Science.gov

Sample records for suction feeding fishes

  1. Some aspects of the hydrodynamics of suction feeding of fish

    NASA Astrophysics Data System (ADS)

    de Jong, M. Christel; Sparenberg, J. A.; de Vries, J.

    1987-10-01

    A mathematical model is described for the suction feeding of fish up to the moment that the gills are opened. The free moving body of the fish is allowed to accelerate when the volume of the mouth cavity is enlarged or when an external force which represents a propulsive action of the caudal fin, is exerted at the body. Some numerical results are given.

  2. Body ram, not suction, is the primary axis of suction-feeding diversity in spiny-rayed fishes.

    PubMed

    Longo, Sarah J; McGee, Matthew D; Oufiero, Christopher E; Waltzek, Thomas B; Wainwright, Peter C

    2016-01-01

    Suction-feeding fishes exhibit diverse prey-capture strategies that vary in their relative use of suction and predator approach (ram), which is often referred to as the ram-suction continuum. Previous research has found that ram varies more than suction distance among species, such that ram accounts for most differences in prey-capture behaviors. To determine whether these findings hold at broad evolutionary scales, we collected high-speed videos of 40 species of spiny-rayed fishes (Acanthomorpha) feeding on live prey. For each strike, we calculated the contributions of suction, body ram (swimming) and jaw ram (mouth movement relative to the body) to closing the distance between predator and prey. We confirm that the contribution of suction distance is limited even in this phylogenetically and ecologically broad sample of species, with the extreme suction area of prey-capture space conspicuously unoccupied. Instead of a continuum from suction to ram, we find that variation in body ram is the major factor underlying the diversity of prey-capture strategies among suction-feeding fishes. Independent measurement of the contribution of jaw ram revealed that it is an important component of diversity among spiny-rayed fishes, with a number of ecomorphologies relying heavily on jaw ram, including pivot feeding in syngnathiforms, extreme jaw protruders and benthic sit-and-wait ambush predators. A combination of morphological and behavioral innovations has allowed fish to invade the extreme jaw ram area of prey-capture space. We caution that while two-species comparisons may support a ram-suction trade-off, these patterns do not speak to broader patterns across spiny-rayed fishes.

  3. Body ram, not suction, is the primary axis of suction-feeding diversity in spiny-rayed fishes.

    PubMed

    Longo, Sarah J; McGee, Matthew D; Oufiero, Christopher E; Waltzek, Thomas B; Wainwright, Peter C

    2016-01-01

    Suction-feeding fishes exhibit diverse prey-capture strategies that vary in their relative use of suction and predator approach (ram), which is often referred to as the ram-suction continuum. Previous research has found that ram varies more than suction distance among species, such that ram accounts for most differences in prey-capture behaviors. To determine whether these findings hold at broad evolutionary scales, we collected high-speed videos of 40 species of spiny-rayed fishes (Acanthomorpha) feeding on live prey. For each strike, we calculated the contributions of suction, body ram (swimming) and jaw ram (mouth movement relative to the body) to closing the distance between predator and prey. We confirm that the contribution of suction distance is limited even in this phylogenetically and ecologically broad sample of species, with the extreme suction area of prey-capture space conspicuously unoccupied. Instead of a continuum from suction to ram, we find that variation in body ram is the major factor underlying the diversity of prey-capture strategies among suction-feeding fishes. Independent measurement of the contribution of jaw ram revealed that it is an important component of diversity among spiny-rayed fishes, with a number of ecomorphologies relying heavily on jaw ram, including pivot feeding in syngnathiforms, extreme jaw protruders and benthic sit-and-wait ambush predators. A combination of morphological and behavioral innovations has allowed fish to invade the extreme jaw ram area of prey-capture space. We caution that while two-species comparisons may support a ram-suction trade-off, these patterns do not speak to broader patterns across spiny-rayed fishes. PMID:26596534

  4. Energetic limitations on suction feeding performance in centrarchid fishes.

    PubMed

    Carroll, Andrew M; Wainwright, Peter C

    2009-10-01

    Energetic analysis of ecologically relevant behaviors can be useful because animals are energetically limited by available muscle mass. In this study we hypothesized that two major determinants of suction feeding performance, the magnitudes of buccal volumetric expansion and subambient buccal pressure, would be correlated with, and limited by, available muscle mass. At least four individuals of three centrarchid species were studied: largemouth bass (Micropterus salmoides), bluegill (Lepomis macrochirus) and green sunfish (Lepomis cyanellus). Buccal pressure was measured directly via cannulation of the buccal cavity with a catheter-tipped pressure transducer. Buccal expansion was estimated from lateral high-speed video (500 or 1000 Hz) sequences and published data on internal kinematics of largemouth bass. These estimates were calibrated from silicone casts made of the buccal cavity post-mortem. Estimated work and power were found to be significantly correlated with muscle mass over all individuals. The slopes of these relationships, estimates of mass-specific muscle work and power, were found to be 11+/-2 J kg(-1) and 300+/-75 W kg(-1), respectively. These estimates are consistent with observations made of in vivo and in vitro muscle use and with digital particle image velocimetry measurements of water flow in feeding centrarchids. A direct trade-off between mean pressure and change in volume was observed, when the latter was normalized to muscle mass. We conclude that available muscle mass may be a useful metric of suction feeding performance, and that the ratio of muscle mass to buccal volume may be a useful predictor of subambient buccal pressure magnitude. PMID:19801429

  5. Hydrodynamic Constraints of Suction Feeding in Low Reynolds Numbers, and the Critical Period of Larval Fishes.

    PubMed

    Holzman, Roi; China, Victor; Yaniv, Sarit; Zilka, Miri

    2015-07-01

    Larval fishes suffer prodigious mortality rates, eliminating 99% of the cohort within a few days after their first feeding. Hjort (1914) famously attributed this "critical period" of low survival to larval inability to obtain sufficient food. We discuss recent experimental and modeling work, suggesting that the viscous hydrodynamic regime have marked effects on the mechanism of suction feeding in larval fish. As larvae grow, the size of the gape and associated volume of the mouth increase. At the same time, larvae swim faster and can generate faster suction flows, thus transiting to a hydrodynamic regime of higher Reynolds numbers. This hydrodynamic regime further leads to changes in the spatio-temporal patterns of flow in front of the mouth, and an increasing ability in larger larvae to exert suction forces on the prey. Simultaneously, the increase in swimming speed and the distance from which the prey is attacked result in higher rates of encountering prey by larger (older) larvae. In contrast, during the first few days after feeding commence the lower rates of encounter and success in feeding translate to low feeding rates. We conclude that young larvae experience "hydrodynamic starvation," in which low Reynolds numbers mechanically limit their feeding performance even under high densities of prey.

  6. New insights from serranid fishes on the role of trade-offs in suction-feeding diversification.

    PubMed

    Oufiero, Christopher E; Holzman, Roi A; Young, Forrest A; Wainwright, Peter C

    2012-11-01

    Suction feeding is central to prey capture in the vast majority of ray-finned fishes and has been well studied from a detailed, mechanistic perspective. Several major trade-offs are thought to have shaped the diversification of suction-feeding morphology and behavior, and have become well established in the literature. We revisited several of these expectations in a study of prey capture morphology and kinematics in 30 species of serranid fishes, a large, ecologically variable group that exhibits diverse combinations of suction and forward locomotion. We find that: (1) diversity among species in the morphological potential to generate suction changes drastically across the range of attack speeds that species use, with all species that use high-speed attacks having low capacity to generate suction, whereas slow-speed attackers exhibit the full range of suction abilities (this pattern indicates a more complex 'ram-suction continuum' than previously recognized); (2) there is no trade-off between the mechanical advantage of the lower jaw opening lever and the speed of jaw depression, revealing that this simple interpretation of lever mechanics fails to predict kinematic diversity; (3) high-speed attackers show increased cranial excursions, potentially to compensate for a decrease in accuracy; (4) the amount of jaw protrusion is positively related to attack speed, but not suction capacity; and (5) a principal component analysis revealed three significant multivariate axes of kinematic variation among species. Two of the three axes were correlated with the morphological potential to generate suction, indicating important but complex relationships between kinematics and suction potential. These results are consistent with other recent studies that show that trade-offs derived from simple biomechanical models may be less of a constraint on the evolutionary diversification of fish feeding systems than previously thought. PMID:22855615

  7. New insights from serranid fishes on the role of trade-offs in suction-feeding diversification.

    PubMed

    Oufiero, Christopher E; Holzman, Roi A; Young, Forrest A; Wainwright, Peter C

    2012-11-01

    Suction feeding is central to prey capture in the vast majority of ray-finned fishes and has been well studied from a detailed, mechanistic perspective. Several major trade-offs are thought to have shaped the diversification of suction-feeding morphology and behavior, and have become well established in the literature. We revisited several of these expectations in a study of prey capture morphology and kinematics in 30 species of serranid fishes, a large, ecologically variable group that exhibits diverse combinations of suction and forward locomotion. We find that: (1) diversity among species in the morphological potential to generate suction changes drastically across the range of attack speeds that species use, with all species that use high-speed attacks having low capacity to generate suction, whereas slow-speed attackers exhibit the full range of suction abilities (this pattern indicates a more complex 'ram-suction continuum' than previously recognized); (2) there is no trade-off between the mechanical advantage of the lower jaw opening lever and the speed of jaw depression, revealing that this simple interpretation of lever mechanics fails to predict kinematic diversity; (3) high-speed attackers show increased cranial excursions, potentially to compensate for a decrease in accuracy; (4) the amount of jaw protrusion is positively related to attack speed, but not suction capacity; and (5) a principal component analysis revealed three significant multivariate axes of kinematic variation among species. Two of the three axes were correlated with the morphological potential to generate suction, indicating important but complex relationships between kinematics and suction potential. These results are consistent with other recent studies that show that trade-offs derived from simple biomechanical models may be less of a constraint on the evolutionary diversification of fish feeding systems than previously thought.

  8. Time resolved measurements of the flow generated by suction feeding fish

    NASA Astrophysics Data System (ADS)

    Day, Steven W.; Higham, Timothy E.; Wainwright, Peter C.

    The majority of aquatic vertebrates are suction feeders: by rapidly expanding the mouth cavity they generate a fluid flow outside of their head in order to draw prey into their mouth. In addition to the biological relevance, the generated flow field is interesting fluid mechanically as it incorporates high velocities, is localized in front of the mouth, and is unsteady, typically lasting between 10 and 50 ms. Using manometry and high-speed particle image velocimetry, this is the first study to quantify pressure within and outside the mouth of a feeding fish while simultaneously measuring the velocity field outside the mouth. Measurements with a high temporal (2 ms) and spatial (<1 mm) resolution were made for several feeding events of a single largemouth bass (Micropterus salmoides). General properties of the flow were evaluated, including the transient velocity field, its relationship to pressure within the mouth and pressure at the prey. We find that throughout the feeding event a relationship exists for the magnitude of fluid speed as a function of distance from the predator mouth that is based on scaling the velocity field according to the size of the mouth opening and the magnitude of fluid speed at the mouth. The velocity field is concentrated within an area extending approximately one mouth diameter from the fish and the generated pressure field is even more local to the mouth aperture. Although peak suction pressures measured inside the mouth were slightly larger than those that were predicted using the equations of motion, we find that these equations give a very accurate prediction of the timing of peak pressure, so long as the unsteady nature of the flow is included.

  9. Time resolved measurements of the flow generated by suction feeding fish

    NASA Astrophysics Data System (ADS)

    Day, Steven W.; Higham, Timothy E.; Wainwright, Peter C.

    2007-11-01

    The majority of aquatic vertebrates are suction feeders: by rapidly expanding the mouth cavity they generate a fluid flow outside of their head in order to draw prey into their mouth. In addition to the biological relevance, the generated flow field is interesting fluid mechanically as it incorporates high velocities, is localized in front of the mouth, and is unsteady, typically lasting between 10 and 50 ms. Using manometry and high-speed particle image velocimetry, this is the first study to quantify pressure within and outside the mouth of a feeding fish while simultaneously measuring the velocity field outside the mouth. Measurements with a high temporal (2 ms) and spatial (<1 mm) resolution were made for several feeding events of a single largemouth bass ( Micropterus salmoides). General properties of the flow were evaluated, including the transient velocity field, its relationship to pressure within the mouth and pressure at the prey. We find that throughout the feeding event a relationship exists for the magnitude of fluid speed as a function of distance from the predator mouth that is based on scaling the velocity field according to the size of the mouth opening and the magnitude of fluid speed at the mouth. The velocity field is concentrated within an area extending approximately one mouth diameter from the fish and the generated pressure field is even more local to the mouth aperture. Although peak suction pressures measured inside the mouth were slightly larger than those that were predicted using the equations of motion, we find that these equations give a very accurate prediction of the timing of peak pressure, so long as the unsteady nature of the flow is included.

  10. Determining Suction Feeding Efficiency in the Bowfin fish (Amia) using Particle Image Velocimery and Computaional Fluid Dynamics

    NASA Astrophysics Data System (ADS)

    Rua, Yenny; Kharbouch, Karim; Sanford, Christopher; Reckinger, Shanon

    2014-11-01

    Suction feeding is the most common form of prey capture in aquatic vertebrates. During the early evolution of fishes there was a major change in shape of the mouth, from a wedge shaped mouth opening in more primitive fishes to a more circular and planar mouth. This change in shape resulted from increased mobility of a key upper jaw bone, the maxilla. It has been suggested that this change in shape dramatically increased suction feeding efficiency. This study examines the hydrodynamic effects of these two mouth shapes in the same animal, the bowfin fish (Amia calva). 2D Particle Image Velocimetry (PIV) is used to analyze suction feeding events. Post-processing algorithms have been developed to determine the flow rate of water into the mouth of the fish; the area of fluid, the velocity of fluid and the volume of fluid affected by the fish; the velocity of the fluid at the mouth, as well as the velocity of the fluid as a function of the distance from the mouth, finally the force exerted on the fluid by the fish is also determined. Lastly, a numerical model has been developed for comparison using a non-uniform mesh, which adapts dynamically in space and time to the fish feeding event. The realistic geometry of the fish's head is modeled in CAD.

  11. The pressures of suction feeding: the relation between buccal pressure and induced fluid speed in centrarchid fishes.

    PubMed

    Higham, Timothy E; Day, Steven W; Wainwright, Peter C

    2006-09-01

    Suction feeding fish rapidly expand their oral cavity, resulting in a flow of water directed towards the mouth that is accompanied by a drop in pressure inside the buccal cavity. Pressure inside the mouth and fluid speed external to the mouth are understood to be mechanically linked but the relationship between them has never been empirically determined in any suction feeder. We present the first simultaneous measurements of fluid speed and buccal pressure during suction feeding in fishes. Digital particle image velocimetry (DPIV) and high-speed video were used to measure the maximum fluid speed in front of the mouth of four largemouth bass and three bluegill sunfish by positioning a vertical laser sheet on the mid-sagittal plane of the fish. Peak magnitude of pressure inside the buccal cavity was quantified using a transducer positioned within a catheter that opened into the dorsal wall of the buccal cavity. In both species the time of peak pressure preceded the time of peak fluid speed by as much as 42 ms, indicating a role for unsteady flow effects in shaping this relation. We parameterized an existing model of suction feeding to determine whether the relationship between peak pressures and fluid speeds that we observed could be predicted using just a few kinematic variables. The model predicted much higher fluid speeds than we measured at all values of peak pressure and gave a scaling exponent between them (0.51) that was higher than observed (0.36 for largemouth bass, 0.38 for bluegill). The scaling between peak buccal pressure and peak fluid speed at the mouth aperture differed in the two species, supporting the recent conclusion that species morphology affects this relation such that a general pattern may not hold. PMID:16916963

  12. Hydroponic Feed With Suction

    NASA Technical Reports Server (NTRS)

    Cox, William M.; Brown, Christopher S.; Dreschel, Thomas W.

    1994-01-01

    Placing nutrient solution under suction increases growth. Foam plug seals growing stem of plant, making it possible to maintain suction in nutrient liquid around roots. Jar wrapped in black tape to keep out light. Potential use in terrestrial applications in arid climates or in labor-intensive agricultural situations.

  13. Reevaluating Musculoskeletal Linkages in Suction-Feeding Fishes with X-Ray Reconstruction of Moving Morphology (XROMM).

    PubMed

    Camp, Ariel L; Brainerd, Elizabeth L

    2015-07-01

    Suction-feeding fishes encompass a vast diversity of morphologies and ecologies, but during feeding they all rely on musculoskeletal linkages and levers to transform the shortening of muscle into 3D expansion of the mouth cavity. To relate the shape of these skeletal elements to their function in expansion of the mouth, four-bar linkage models have been developed and widely used in studies of ecology, evolution, and development. However, we have lacked the ability to test the predictions of these 2D linkage models against the actual 3D motions of fishes' skulls. A new imaging method, X-ray Reconstruction of Moving Morphology (XROMM), now makes it possible to measure 3D skeletal motions relative to other bones within the head and relative to the fish's body, and thereby to examine directly the proposed linkages. We used XROMM to examine the opercular linkage, in which shortening of the levator operculi muscle is hypothesized to retract the operculum, and thereby the interoperculum and interoperculomandibular ligament to generate depression of the lower jaw about the quadratomandibular joint. XROMM animations of suction strikes in largemouth bass revealed that the operculum is indeed retracted relative to the suspensorium as the levator operculi muscle shortens and the jaw depresses. However, the four-bar model of this linkage overestimates the depression of the jaw by nearly a factor of two. Therefore, caution should be used in interpreting and applying the predictions of this linkage model. When we measured kinematics relative to the fish's body, we found that the operculum was relatively stable, whereas the suspensorium was elevated along with the neurocranium, pushing the quadratomandibular joint forward to produce depression of the jaw. Thus, it is the epaxial muscles elevating the neurocranium that powers depression of the jaw through the opercular linkage. However, the levator operculi muscle plays a crucial role in stabilizing the operculum to allow elevation

  14. Multidimensional analysis of suction feeding performance in fishes: fluid speed, acceleration, strike accuracy and the ingested volume of water.

    PubMed

    Higham, Timothy E; Day, Steven W; Wainwright, Peter C

    2006-07-01

    Suction feeding fish draw prey into the mouth using a flow field that they generate external to the head. In this paper we present a multidimensional perspective on suction feeding performance that we illustrate in a comparative analysis of suction feeding ability in two members of Centrarchidae, the largemouth bass (Micropterus salmoides) and bluegill sunfish (Lepomis macrochirus). We present the first direct measurements of maximum fluid speed capacity, and we use this to calculate local fluid acceleration and volumetric flow rate. We also calculated the ingested volume and a novel metric of strike accuracy. In addition, we quantified for each species the effects of gape magnitude, time to peak gape, and swimming speed on features of the ingested volume of water. Digital particle image velocimetry (DPIV) and high-speed video were used to measure the flow in front of the mouths of three fish from each species in conjunction with a vertical laser sheet positioned on the mid-sagittal plane of the fish. From this we quantified the maximum fluid speed (in the earthbound and fish's frame of reference), acceleration and ingested volume. Our method for determining strike accuracy involved quantifying the location of the prey relative to the center of the parcel of ingested water. Bluegill sunfish generated higher fluid speeds in the earthbound frame of reference, accelerated the fluid faster, and were more accurate than largemouth bass. However, largemouth bass ingested a larger volume of water and generated a higher volumetric flow rate than bluegill sunfish. In addition, because largemouth bass swam faster during prey capture, they generated higher fluid speeds in the fish's frame of reference. Thus, while bluegill can exert higher drag forces on stationary prey items, largemouth bass more quickly close the distance between themselves and prey. The ingested volume and volumetric flow rate significantly increased as gape increased for both species, while time to peak

  15. Anterior-to-posterior wave of buccal expansion in suction feeding fishes is critical for optimizing fluid flow velocity profile.

    PubMed

    Bishop, Kristin L; Wainwright, Peter C; Holzman, Roi

    2008-11-01

    In fishes that employ suction feeding, coordinating the timing of peak flow velocity with mouth opening is likely to be an important feature of prey capture success because this will allow the highest forces to be exerted on prey items when the jaws are fully extended and the flow field is at its largest. Although it has long been known that kinematics of buccal expansion in feeding fishes are characterized by an anterior-to-posterior wave of expansion, this pattern has not been incorporated in most previous computational models of suction feeding. As a consequence, these models have failed to correctly predict the timing of peak flow velocity, which according to the currently available empirical data should occur around the time of peak gape. In this study, we use a simple fluid dynamic model to demonstrate that the inclusion of an anterior-to-posterior wave of buccal expansion can correctly reproduce the empirically determined flow velocity profile, although only under very constrained conditions, whereas models that do not allow this wave of expansion inevitably predict peak velocity earlier in the strike, when the gape is less than half of its maximum. The conditions that are required to produce a realistic velocity profile are as follows: (i) a relatively long time lag between mouth opening and expansion of the more posterior parts of the mouth, (ii) a short anterior portion of the mouth relative to more posterior sections, and (iii) a pattern of movement that begins slowly and then rapidly accelerates. Greater maximum velocities were generated in simulations without the anterior-to-posterior wave of expansion, suggesting a trade-off between maximizing fluid speed and coordination of peak fluid speed with peak gape.

  16. Swimming muscles power suction feeding in largemouth bass.

    PubMed

    Camp, Ariel L; Roberts, Thomas J; Brainerd, Elizabeth L

    2015-07-14

    Most aquatic vertebrates use suction to capture food, relying on rapid expansion of the mouth cavity to accelerate water and food into the mouth. In ray-finned fishes, mouth expansion is both fast and forceful, and therefore requires considerable power. However, the cranial muscles of these fishes are relatively small and may not be able to produce enough power for suction expansion. The axial swimming muscles of these fishes also attach to the feeding apparatus and have the potential to generate mouth expansion. Because of their large size, these axial muscles could contribute substantial power to suction feeding. To determine whether suction feeding is powered primarily by axial muscles, we measured the power required for suction expansion in largemouth bass and compared it to the power capacities of the axial and cranial muscles. Using X-ray reconstruction of moving morphology (XROMM), we generated 3D animations of the mouth skeleton and created a dynamic digital endocast to measure the rate of mouth volume expansion. This time-resolved expansion rate was combined with intraoral pressure recordings to calculate the instantaneous power required for suction feeding. Peak expansion powers for all but the weakest strikes far exceeded the maximum power capacity of the cranial muscles. The axial muscles did not merely contribute but were the primary source of suction expansion power and generated up to 95% of peak expansion power. The recruitment of axial muscle power may have been crucial for the evolution of high-power suction feeding in ray-finned fishes.

  17. Origins, Innovations, and Diversification of Suction Feeding in Vertebrates.

    PubMed

    Wainwright, Peter C; McGee, Matthew D; Longo, Sarah J; Hernandez, L Patricia

    2015-07-01

    We review the origins, prominent innovations, and major patterns of diversification in suction feeding by vertebrates. Non-vertebrate chordates and larval lamprey suspension-feed by capturing small particles in pharyngeal mucous. In most of these lineages the gentle flows that transport particles are generated by buccal cilia, although larval lamprey and thaliacean urochordates have independently evolved a weak buccal pump to generate an oscillating flow of water that is powered by elastic recovery of the pharynx following compression by buccal muscles. The evolution of jaws and the hyoid facilitated powerful buccal expansion and high-performance suction feeding as found today throughout aquatic vertebrates. We highlight three major innovations in suction feeding. Most vertebrate suction feeders have mechanisms that occlude the corners of the open mouth during feeding. This produces a planar opening that is often nearly circular in shape. Both features contribute to efficient flow of water into the mouth and help direct the flow to the area directly in front of the mouth's aperture. Among several functions that have been identified for protrusion of the upper jaw, is an increase in the hydrodynamic forces that suction feeders exert on their prey. Protrusion of the upper jaw has evolved five times in ray-finned fishes, including in two of the most successful teleost radiations, cypriniforms and acanthomorphs, and is found in about 60% of living teleost species. Diversification of the mechanisms of suction feeding and of feeding behavior reveals that suction feeders with high capacity for suction rarely approach their prey rapidly, while slender-bodied predators with low capacity for suction show the full range of attack speeds. We hypothesize that a dominant axis of diversification among suction feeders involves a trade-off between the forces that are exerted on prey and the volume of water that is ingested. PMID:25920508

  18. Swimming muscles power suction feeding in largemouth bass.

    PubMed

    Camp, Ariel L; Roberts, Thomas J; Brainerd, Elizabeth L

    2015-07-14

    Most aquatic vertebrates use suction to capture food, relying on rapid expansion of the mouth cavity to accelerate water and food into the mouth. In ray-finned fishes, mouth expansion is both fast and forceful, and therefore requires considerable power. However, the cranial muscles of these fishes are relatively small and may not be able to produce enough power for suction expansion. The axial swimming muscles of these fishes also attach to the feeding apparatus and have the potential to generate mouth expansion. Because of their large size, these axial muscles could contribute substantial power to suction feeding. To determine whether suction feeding is powered primarily by axial muscles, we measured the power required for suction expansion in largemouth bass and compared it to the power capacities of the axial and cranial muscles. Using X-ray reconstruction of moving morphology (XROMM), we generated 3D animations of the mouth skeleton and created a dynamic digital endocast to measure the rate of mouth volume expansion. This time-resolved expansion rate was combined with intraoral pressure recordings to calculate the instantaneous power required for suction feeding. Peak expansion powers for all but the weakest strikes far exceeded the maximum power capacity of the cranial muscles. The axial muscles did not merely contribute but were the primary source of suction expansion power and generated up to 95% of peak expansion power. The recruitment of axial muscle power may have been crucial for the evolution of high-power suction feeding in ray-finned fishes. PMID:26100863

  19. Swimming muscles power suction feeding in largemouth bass

    PubMed Central

    Camp, Ariel L.; Roberts, Thomas J.; Brainerd, Elizabeth L.

    2015-01-01

    Most aquatic vertebrates use suction to capture food, relying on rapid expansion of the mouth cavity to accelerate water and food into the mouth. In ray-finned fishes, mouth expansion is both fast and forceful, and therefore requires considerable power. However, the cranial muscles of these fishes are relatively small and may not be able to produce enough power for suction expansion. The axial swimming muscles of these fishes also attach to the feeding apparatus and have the potential to generate mouth expansion. Because of their large size, these axial muscles could contribute substantial power to suction feeding. To determine whether suction feeding is powered primarily by axial muscles, we measured the power required for suction expansion in largemouth bass and compared it to the power capacities of the axial and cranial muscles. Using X-ray reconstruction of moving morphology (XROMM), we generated 3D animations of the mouth skeleton and created a dynamic digital endocast to measure the rate of mouth volume expansion. This time-resolved expansion rate was combined with intraoral pressure recordings to calculate the instantaneous power required for suction feeding. Peak expansion powers for all but the weakest strikes far exceeded the maximum power capacity of the cranial muscles. The axial muscles did not merely contribute but were the primary source of suction expansion power and generated up to 95% of peak expansion power. The recruitment of axial muscle power may have been crucial for the evolution of high-power suction feeding in ray-finned fishes. PMID:26100863

  20. Quantification of flow during suction feeding in bluegill sunfish.

    PubMed

    Ferry-Graham, Lara A; Wainwright, Peter C; Lauder, George V

    2003-01-01

    Nearly all aquatic-feeding vertebrates use some amount of suction to capture prey items. Suction prey capture occurs by accelerating a volume of water into the mouth and taking a prey item along with it. Yet, until recently, we lacked the necessary techniques and analytical tools to quantify the flow regime generated by feeding fish. We used a new approach; Digital Particle Image Velocimetery (DPIV) to measure several attributes of the flow generated by feeding bluegill sunfish. We found that the temporal pattern of flow was notably compressed during prey capture. Flow velocity increased rapidly to its peak within 20 ms of the onset of the strike, and this peak corresponded to the time that the prey entered the mouth during capture. The rapid acceleration and deceleration of water suggests that timing is critical for the predator in positioning itself relative to the prey so that it can be drawn into the mouth along with the water. We also found that the volume of water affected by suction was spatially limited. Only rarely did we measure significant flow beyond 1.75 cm of the mouth aperture (in 20 cm fish), further emphasizing the importance of mechanisms, like locomotion, that place the fish mouth in close proximity to the prey. We found that the highest flows towards the mouth along the fish midline were generated not immediately in front of the open mouth, but approximately 0.5 cm anterior to the mouth opening. Away from the midline the peak in flow was closer to the mouth. We propose that this pattern indicates the presence of a bow wave created by the locomotor efforts of the fish. In this scheme, the bow wave acts antagonistically to the flow of water generated by suction, the net effect being to push the region of peak flow away from the open mouth. The peak was located farther from the mouth opening in strikes accompanied by faster locomotion, suggesting faster fish created larger bow waves. PMID:16351901

  1. Suction power output and the inertial cost of rotating the neurocranium to generate suction in fish.

    PubMed

    Van Wassenbergh, Sam; Day, Steven W; Hernández, L Patricia; Higham, Timothy E; Skorczewski, Tyler

    2015-05-01

    To expand the buccal cavity, many suction-feeding fishes rely on a considerable contribution from dorsal rotation of the dorsal part of the head including the brains, eyes, and several bones forming the braincase and skull roof (jointly referred to as the neurocranium). As the neurocranium takes up a large part of the total mass of the head, this rotation may incur a considerable inertial cost. If so, this would suggest a significant selective pressure on the kinematics and mass distribution of the neurocranium of suction feeders. Here, an inverse dynamic model is formulated to calculate the instantaneous power required to rotate the neurocranium, approximated by a quarter ellipsoid volume of homogeneous density, as well as to calculate the instantaneous suction power based on intra-oral pressure and head volume quantifications. We applied this model to largemouth bass (Micropterus salmoides) and found that the power required to rotate the neurocranium accounts for only about 4% of the power required to suck water into the mouth. Furthermore, recovery of kinetic energy from the rotating neurocranium converted into suction work may be possible during the phase of neurocranial deceleration. Thus, we suggest that only a negligible proportion of the power output of the feeding muscles is lost as inertial costs in the largemouth bass. Consequently, the feeding performance of piscivorous suction feeders with generalised morphology, comparable to our model species, is not limited by neurocranial motion during head expansion. This suggests that it is thus not likely to be a factor of importance in the evolution of cranial shape and size. PMID:25769945

  2. Characterization of zebrafish larvae suction feeding flow using μPIV and optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Pekkan, Kerem; Chang, Brian; Uslu, Fazil; Mani, Karthick; Chen, Chia-Yuan; Holzman, Roi

    2016-07-01

    The hydrodynamics of suction feeding is critical for the survival of fish larvae; failure to capture food during the onset of autonomous feeding can rapidly lead to starvation and mortality. Fluid mechanics experiments that investigate the suction feeding of suspended particles are limited to adult fishes, which operate at large Reynolds numbers. This manuscript presents the first literature results in which the external velocity fields generated during suction feeding of early zebrafish larvae (2500-20,000 μm total length) are reported using time-resolved microscopic particle image velocimetry. For the larval stages studied, the maximum peak suction velocity of the inflow bolus is measured at a finite distance from the mouth tip and ranges from 1 to 8 mm/s. The average pressure gradient and the velocity profile proximal to the buccal (mouth) cavity are calculated, and two distinct trends are identified. External recirculation regions and reverse flow feeding cycles are also observed and quantified. One of the unresolved questions in fish suction feeding is the shape and dynamics of the buccal cavity during suction feeding; optical coherence tomography imaging is found to be useful for reconstructing the mouth kinematics. The projected area of the mouth cavity during the feeding cycle varies up to 160 and 22 % for the transverse and mid-sagittal planes, respectively. These findings can inspire novel hydrodynamically efficient biomedical and microfluidic devices.

  3. Feeding Kinematics, Suction, and Hydraulic Jetting Performance of Harbor Seals (Phoca vitulina)

    PubMed Central

    Marshall, Christopher D.; Wieskotten, Sven; Hanke, Wolf; Hanke, Frederike D.; Marsh, Alyssa; Kot, Brian; Dehnhardt, Guido

    2014-01-01

    The feeding kinematics, suction and hydraulic jetting capabilities of captive harbor seals (Phoca vitulina) were characterized during controlled feeding trials. Feeding trials were conducted using a feeding apparatus that allowed a choice between biting and suction, but also presented food that could be ingested only by suction. Subambient pressure exerted during suction feeding behaviors was directly measured using pressure transducers. The mean feeding cycle duration for suction-feeding events was significantly shorter (0.15±0.09 s; P<0.01) than biting feeding events (0.18±0.08 s). Subjects feeding in-water used both a suction and a biting feeding mode. Suction was the favored feeding mode (84% of all feeding events) compared to biting, but biting comprised 16% of feeding events. In addition, seals occasionally alternated suction with hydraulic jetting, or used hydraulic jetting independently, to remove fish from the apparatus. Suction and biting feeding modes were kinematically distinct regardless of feeding location (in-water vs. on-land). Suction was characterized by a significantly smaller gape (1.3±0.23 cm; P<0.001) and gape angle (12.9±2.02°), pursing of the rostral lips to form a circular aperture, and pursing of the lateral lips to occlude lateral gape. Biting was characterized by a large gape (3.63±0.21 cm) and gape angle (28.8±1.80°; P<0.001) and lip curling to expose teeth. The maximum subambient pressure recorded was 48.8 kPa. In addition, harbor seals were able to jet water at food items using suprambient pressure, also known as hydraulic jetting. The maximum hydraulic jetting force recorded was 53.9 kPa. Suction and hydraulic jetting where employed 90.5% and 9.5%, respectively, during underwater feeding events. Harbor seals displayed a wide repertoire of behaviorally flexible feeding strategies to ingest fish from the feeding apparatus. Such flexibility of feeding strategies and biomechanics likely forms the basis of their opportunistic

  4. High Speed Tomographic PIV Measurements of Copepod Sensitivity to a Suction-Feeding Predator Mimic

    NASA Astrophysics Data System (ADS)

    Yen, J.; Murphy, D. W.; Fan, L.; Skipper, A.; Webster, D. R.

    2013-11-01

    Copepods, which sense their fluid environment with long, setae-bearing antennules, often serve as prey to fish. The fluid disturbance created by fish feeding is a combination of a bow wave created by swimming towards the prey with an open mouth and a sudden, high speed flow into the fish's mouth created by suction. The sensitivity and reaction of copepods to the dynamic, high acceleration flow created by a suction feeding fish have not been well explored. In the present study, a suction feeding piscine predator mimic is developed and tested with copepods from a fish-containing (marine) environment (Calanus finmarchicus) and with copepods from a fish-less (alpine lake) environment (Hesperodiaptomus shoshone). Flow fields created by the impulsive siphon are measured with a high-speed tomographic particle image velocimetry (PIV) system. Escape success and kinematics of the two species are compared. Finally, using volumetric flow measurements, the hydrodynamic signal measured along each copepod's antennules at the time point of escape is compared between species.

  5. Absence of suction feeding ichthyosaurs and its implications for triassic mesopelagic paleoecology.

    PubMed

    Motani, Ryosuke; Ji, Cheng; Tomita, Taketeru; Kelley, Neil; Maxwell, Erin; Jiang, Da-yong; Sander, Paul Martin

    2013-01-01

    Mesozoic marine reptiles and modern marine mammals are often considered ecological analogs, but the extent of their similarity is largely unknown. Particularly important is the presence/absence of deep-diving suction feeders among Mesozoic marine reptiles because this would indicate the establishment of mesopelagic cephalopod and fish communities in the Mesozoic. A recent study suggested that diverse suction feeders, resembling the extant beaked whales, evolved among ichthyosaurs in the Triassic. However, this hypothesis has not been tested quantitatively. We examined four osteological features of jawed vertebrates that are closely linked to the mechanism of suction feeding, namely hyoid corpus ossification/calcification, hyobranchial apparatus robustness, mandibular bluntness, and mandibular pressure concentration index. Measurements were taken from 18 species of Triassic and Early Jurassic ichthyosaurs, including the presumed suction feeders. Statistical comparisons with extant sharks and marine mammals of known diets suggest that ichthyosaurian hyobranchial bones are significantly more slender than in suction-feeding sharks or cetaceans but similar to those of ram-feeding sharks. Most importantly, an ossified hyoid corpus to which hyoid retractor muscles attach is unknown in all but one ichthyosaur, whereas a strong integration of the ossified corpus and cornua of the hyobranchial apparatus has been identified in the literature as an important feature of suction feeders. Also, ichthyosaurian mandibles do not narrow rapidly to allow high suction pressure concentration within the oral cavity, unlike in beaked whales or sperm whales. In conclusion, it is most likely that Triassic and Early Jurassic ichthyosaurs were 'ram-feeders', without any beaked-whale-like suction feeder among them. When combined with the inferred inability for dim-light vision in relevant Triassic ichthyosaurs, the fossil record of ichthyosaurs does not suggest the establishment of modern

  6. Absence of Suction Feeding Ichthyosaurs and Its Implications for Triassic Mesopelagic Paleoecology

    PubMed Central

    Motani, Ryosuke; Ji, Cheng; Tomita, Taketeru; Kelley, Neil; Maxwell, Erin; Jiang, Da-yong; Sander, Paul Martin

    2013-01-01

    Mesozoic marine reptiles and modern marine mammals are often considered ecological analogs, but the extent of their similarity is largely unknown. Particularly important is the presence/absence of deep-diving suction feeders among Mesozoic marine reptiles because this would indicate the establishment of mesopelagic cephalopod and fish communities in the Mesozoic. A recent study suggested that diverse suction feeders, resembling the extant beaked whales, evolved among ichthyosaurs in the Triassic. However, this hypothesis has not been tested quantitatively. We examined four osteological features of jawed vertebrates that are closely linked to the mechanism of suction feeding, namely hyoid corpus ossification/calcification, hyobranchial apparatus robustness, mandibular bluntness, and mandibular pressure concentration index. Measurements were taken from 18 species of Triassic and Early Jurassic ichthyosaurs, including the presumed suction feeders. Statistical comparisons with extant sharks and marine mammals of known diets suggest that ichthyosaurian hyobranchial bones are significantly more slender than in suction-feeding sharks or cetaceans but similar to those of ram-feeding sharks. Most importantly, an ossified hyoid corpus to which hyoid retractor muscles attach is unknown in all but one ichthyosaur, whereas a strong integration of the ossified corpus and cornua of the hyobranchial apparatus has been identified in the literature as an important feature of suction feeders. Also, ichthyosaurian mandibles do not narrow rapidly to allow high suction pressure concentration within the oral cavity, unlike in beaked whales or sperm whales. In conclusion, it is most likely that Triassic and Early Jurassic ichthyosaurs were ‘ram-feeders’, without any beaked-whale-like suction feeder among them. When combined with the inferred inability for dim-light vision in relevant Triassic ichthyosaurs, the fossil record of ichthyosaurs does not suggest the establishment of modern

  7. Absence of suction feeding ichthyosaurs and its implications for triassic mesopelagic paleoecology.

    PubMed

    Motani, Ryosuke; Ji, Cheng; Tomita, Taketeru; Kelley, Neil; Maxwell, Erin; Jiang, Da-yong; Sander, Paul Martin

    2013-01-01

    Mesozoic marine reptiles and modern marine mammals are often considered ecological analogs, but the extent of their similarity is largely unknown. Particularly important is the presence/absence of deep-diving suction feeders among Mesozoic marine reptiles because this would indicate the establishment of mesopelagic cephalopod and fish communities in the Mesozoic. A recent study suggested that diverse suction feeders, resembling the extant beaked whales, evolved among ichthyosaurs in the Triassic. However, this hypothesis has not been tested quantitatively. We examined four osteological features of jawed vertebrates that are closely linked to the mechanism of suction feeding, namely hyoid corpus ossification/calcification, hyobranchial apparatus robustness, mandibular bluntness, and mandibular pressure concentration index. Measurements were taken from 18 species of Triassic and Early Jurassic ichthyosaurs, including the presumed suction feeders. Statistical comparisons with extant sharks and marine mammals of known diets suggest that ichthyosaurian hyobranchial bones are significantly more slender than in suction-feeding sharks or cetaceans but similar to those of ram-feeding sharks. Most importantly, an ossified hyoid corpus to which hyoid retractor muscles attach is unknown in all but one ichthyosaur, whereas a strong integration of the ossified corpus and cornua of the hyobranchial apparatus has been identified in the literature as an important feature of suction feeders. Also, ichthyosaurian mandibles do not narrow rapidly to allow high suction pressure concentration within the oral cavity, unlike in beaked whales or sperm whales. In conclusion, it is most likely that Triassic and Early Jurassic ichthyosaurs were 'ram-feeders', without any beaked-whale-like suction feeder among them. When combined with the inferred inability for dim-light vision in relevant Triassic ichthyosaurs, the fossil record of ichthyosaurs does not suggest the establishment of modern

  8. Independent Evolution of Suction Feeding in Neobatrachia: Feeding Mechanisms in Two Species of Telmatobius (Anura:Telmatobiidae).

    PubMed

    Barrionuevo, José Sebastián

    2016-02-01

    The most common feeding mechanism among aquatic vertebrates as fishes, turtles, and salamanders is inertial suction. However, among the more than 6,400 species of anurans, suction feeding occurs only in pipids. Pipidae is a small basal lineage relative to Neobatrachia, an enormous clade that contains about 96% of extant anurans. The Andean neobatrachian frogs of the genus Telmatobius include strictly aquatic and semiaquatic species. Diet analyses indicate that some species of Telmatobius feed on strictly aquatic prey, but until now their feeding mechanisms have been unknown. Herein, the feeding mechanisms in two species of Telmatobius, that represent the two predominant modes of life in the genus, are explored. The semiaquatic T. oxycephalus and the fully aquatic T. rubigo are studied using high-speed cinematography and standard anatomical techniques to provide a qualitative approach to feeding behavior and a detailed morphological description of the mouth, tongue, hyoid and related muscles. T. oxycephalus uses similar mechanisms of aquatic prey capture as do the vast majority of anurans that are capable of forage in water, whereas the fully aquatic T. rubigo is an inertial suction feeder. This is the first report of an objective record of this unique feeding behavior in a Neobatrachian. Several morphological characters seem to be related with this function and are convergent with those of pipids.

  9. Independent Evolution of Suction Feeding in Neobatrachia: Feeding Mechanisms in Two Species of Telmatobius (Anura:Telmatobiidae).

    PubMed

    Barrionuevo, José Sebastián

    2016-02-01

    The most common feeding mechanism among aquatic vertebrates as fishes, turtles, and salamanders is inertial suction. However, among the more than 6,400 species of anurans, suction feeding occurs only in pipids. Pipidae is a small basal lineage relative to Neobatrachia, an enormous clade that contains about 96% of extant anurans. The Andean neobatrachian frogs of the genus Telmatobius include strictly aquatic and semiaquatic species. Diet analyses indicate that some species of Telmatobius feed on strictly aquatic prey, but until now their feeding mechanisms have been unknown. Herein, the feeding mechanisms in two species of Telmatobius, that represent the two predominant modes of life in the genus, are explored. The semiaquatic T. oxycephalus and the fully aquatic T. rubigo are studied using high-speed cinematography and standard anatomical techniques to provide a qualitative approach to feeding behavior and a detailed morphological description of the mouth, tongue, hyoid and related muscles. T. oxycephalus uses similar mechanisms of aquatic prey capture as do the vast majority of anurans that are capable of forage in water, whereas the fully aquatic T. rubigo is an inertial suction feeder. This is the first report of an objective record of this unique feeding behavior in a Neobatrachian. Several morphological characters seem to be related with this function and are convergent with those of pipids. PMID:26575038

  10. The benefits of planar circular mouths on suction feeding performance

    PubMed Central

    Skorczewski, Tyler; Cheer, Angela; Wainwright, Peter C.

    2012-01-01

    Suction feeding is the most common form of prey capture across aquatic feeding vertebrates and many adaptations that enhance efficiency and performance are expected. Many suction feeders have mechanisms that allow the mouth to form a planar and near-circular opening that is believed to have beneficial hydrodynamic effects. We explore the effects of the flattened and circular mouth opening through computational fluid dynamics simulations that allow comparisons with other mouth profiles. Compared to mouths with lateral notches, we find that the planar mouth opening results in higher flow rates into the mouth and a region of highest flow that is positioned at the centre of the mouth aperture. Planar mouths provide not only for better total fluid flow rates through the mouth but also through the centre of the mouth near where suction feeders position their prey. Circular mouths are shown to provide the quickest capture times for spherical and elliptical prey because they expose the prey item to a large region of high flow. Planar and circular mouths result in higher flow velocities with peak flow located at the centre of the mouth opening and they maximize the capacity of the suction feeders to exert hydrodynamic forces on the prey. PMID:22319101

  11. Role of axial muscles in powering mouth expansion during suction feeding in largemouth bass (Micropterus salmoides).

    PubMed

    Camp, Ariel L; Brainerd, Elizabeth L

    2014-04-15

    Suction-feeding fishes capture food by fast and forceful expansion of the mouth cavity, and axial muscles probably provide substantial power for this feeding behavior. Dorsal expansion of the mouth cavity can only be powered by the epaxial muscles, but both the sternohyoid, shortening against an immobile pectoral girdle to retract the hyoid, and the hypaxial muscles, shortening to retract both the pectoral girdle and hyoid, could contribute ventral expansion power. To determine whether hypaxial muscles generate power for ventral expansion, and the rostrocaudal extent of axial muscle shortening during suction feeding, we measured skeletal kinematics and muscle shortening in largemouth bass (Micropterus salmoides). The three-dimensional motions of the cleithrum and hyoid were measured with X-ray reconstruction of moving morphology (XROMM), and muscle shortening was measured with fluoromicrometry, wherein changes in the distance between radio-opaque intramuscular markers are measured using biplanar X-ray video recording. We found that the hypaxials generated power for ventral suction expansion, shortening (mean of 6.2 mm) to rotate the pectoral girdle caudoventrally (mean of 9.3 deg) and retract the hyoid (mean of 8.5 mm). In contrast, the sternohyoid shortened minimally (mean of 0.48 mm), functioning like a ligament to transmit hypaxial shortening to the hyoid. Hypaxial and epaxial shortening were not confined to the rostral muscle regions, but extended more than halfway down the body during suction expansion. We conclude that hypaxial and epaxial muscles are both crucial for powering mouth expansion in largemouth bass, supporting the integration of axial and cranial musculoskeletal systems for suction feeding. PMID:24363416

  12. Role of axial muscles in powering mouth expansion during suction feeding in largemouth bass (Micropterus salmoides).

    PubMed

    Camp, Ariel L; Brainerd, Elizabeth L

    2014-04-15

    Suction-feeding fishes capture food by fast and forceful expansion of the mouth cavity, and axial muscles probably provide substantial power for this feeding behavior. Dorsal expansion of the mouth cavity can only be powered by the epaxial muscles, but both the sternohyoid, shortening against an immobile pectoral girdle to retract the hyoid, and the hypaxial muscles, shortening to retract both the pectoral girdle and hyoid, could contribute ventral expansion power. To determine whether hypaxial muscles generate power for ventral expansion, and the rostrocaudal extent of axial muscle shortening during suction feeding, we measured skeletal kinematics and muscle shortening in largemouth bass (Micropterus salmoides). The three-dimensional motions of the cleithrum and hyoid were measured with X-ray reconstruction of moving morphology (XROMM), and muscle shortening was measured with fluoromicrometry, wherein changes in the distance between radio-opaque intramuscular markers are measured using biplanar X-ray video recording. We found that the hypaxials generated power for ventral suction expansion, shortening (mean of 6.2 mm) to rotate the pectoral girdle caudoventrally (mean of 9.3 deg) and retract the hyoid (mean of 8.5 mm). In contrast, the sternohyoid shortened minimally (mean of 0.48 mm), functioning like a ligament to transmit hypaxial shortening to the hyoid. Hypaxial and epaxial shortening were not confined to the rostral muscle regions, but extended more than halfway down the body during suction expansion. We conclude that hypaxial and epaxial muscles are both crucial for powering mouth expansion in largemouth bass, supporting the integration of axial and cranial musculoskeletal systems for suction feeding.

  13. Short-Snouted Toothless Ichthyosaur from China Suggests Late Triassic Diversification of Suction Feeding Ichthyosaurs

    PubMed Central

    Sander, P. Martin; Chen, Xiaohong; Cheng, Long; Wang, Xiaofeng

    2011-01-01

    Background Ichthyosaurs were an important group of Mesozoic marine reptiles and existed from the Early Triassic to the early Late Cretaceous. Despite a great diversity in body shapes and feeding adaptations, all share greatly enlarged eyes, an elongated rostrum with numerous conical teeth, and a streamlined body. Methodology/Principal Findings Based on new material from China and the restudy of Shastasaurus pacificus, we here reinterpret the classical large-bodied Late Triassic ichthyosaur genus Shastasaurus to differ greatly from the standard ichthyosaurian body plan, indicating much greater morphological diversity and range of feeding adaptations in ichthyosaurs than previously recognized. Phylogenetic analysis indicates a monophyletic clade consisting of the giant Shonisaurus sikanniensis, Guanlingsaurus liangae, and Shastasaurus pacificus to which the genus name Shastasaurus is applied. Shastasaurus liangae comb. nov. is from the Late Triassic (Carnian) Xiaowa Formation of Guizhou Province, southwestern China. The species combines a diminutive head with an entirely toothless and greatly reduced snout. The species also has by far the highest vertebral count among ichthyosaurs (86 presacral vertebrae and >110 caudal vertebrae), a count that is also very high for tetrapods in general. A reduced toothless snout and a diminutive head is also apparently present in the giant S. sikanniensis and presumably in S. pacificus. Conclusions/Significance In analogy to many modern odontocetes, Shastasaurus is interpreted as a specialized suction feeder on unshelled cephalopods and fish, suggesting a unique but widespread Late Triassic diversification of toothless, suction-feeding ichthyosaurs. Suction feeding has not been hypothesized for any of the other diverse marine reptiles of the Mesozoic before, but in Shastasaurus may be linked to the Late Triassic minimum in atmospheric oxygen. PMID:21625429

  14. Scaling of suction-induced flows in bluegill: morphological and kinematic predictors for the ontogeny of feeding performance.

    PubMed

    Holzman, Roi; Collar, David C; Day, Steven W; Bishop, Kristin L; Wainwright, Peter C

    2008-08-01

    During ontogeny, animals undergo changes in size and shape that result in shifts in performance, behavior and resource use. These ontogenetic changes provide an opportunity to test hypotheses about how the growth of structures affects biological functions. In the present study, we ask how ontogenetic changes in skull biomechanics affect the ability of bluegill sunfish, a high-performance suction feeder, to produce flow speeds and accelerations during suction feeding. The flow of water in front of the mouth was measured directly for fish ranging from young-of-year to large adults, using digital particle imaging velocimetry (DPIV). As bluegill size increased, the magnitude of peak flow speed they produced increased, and the effective suction distance increased because of increasing mouth size. However, throughout the size range, the timing of peak fluid speed remained unchanged, and flow was constrained to approximately one gape distance from the mouth. The observed scaling relationships between standard length and peak flow speed conformed to expectations derived from two biomechanical models, one based on morphological potential to produce suction pressure (the Suction Index model) and the other derived from a combination of morphological and kinematic variables (the Expanding Cone model). The success of these models in qualitatively predicting the observed allometry of induced flow speed reveals that the scaling of cranial morphology underlies the scaling of suction performance in bluegill. PMID:18689419

  15. Modelled three-dimensional suction accuracy predicts prey capture success in three species of centrarchid fishes.

    PubMed

    Kane, Emily A; Higham, Timothy E

    2014-06-01

    Prey capture is critical for survival, and differences in correctly positioning and timing a strike (accuracy) are likely related to variation in capture success. However, an ability to quantify accuracy under natural conditions, particularly for fishes, is lacking. We developed a predictive model of suction hydrodynamics and applied it to natural behaviours using three-dimensional kinematics of three centrarchid fishes capturing evasive and non-evasive prey. A spheroid ingested volume of water (IVW) with dimensions predicted by peak gape and ram speed was verified with known hydrodynamics for two species. Differences in capture success occurred primarily with evasive prey (64-96% success). Micropterus salmoides had the greatest ram and gape when capturing evasive prey, resulting in the largest and most elongate IVW. Accuracy predicted capture success, although other factors may also be important. The lower accuracy previously observed in M. salmoides was not replicated, but this is likely due to more natural conditions in our study. Additionally, we discuss the role of modulation and integrated behaviours in shaping the IVW and determining accuracy. With our model, accuracy is a more accessible performance measure for suction-feeding fishes, which can be used to explore macroevolutionary patterns of prey capture evolution. PMID:24718455

  16. Modelled three-dimensional suction accuracy predicts prey capture success in three species of centrarchid fishes

    PubMed Central

    Kane, Emily A.; Higham, Timothy E.

    2014-01-01

    Prey capture is critical for survival, and differences in correctly positioning and timing a strike (accuracy) are likely related to variation in capture success. However, an ability to quantify accuracy under natural conditions, particularly for fishes, is lacking. We developed a predictive model of suction hydrodynamics and applied it to natural behaviours using three-dimensional kinematics of three centrarchid fishes capturing evasive and non-evasive prey. A spheroid ingested volume of water (IVW) with dimensions predicted by peak gape and ram speed was verified with known hydrodynamics for two species. Differences in capture success occurred primarily with evasive prey (64–96% success). Micropterus salmoides had the greatest ram and gape when capturing evasive prey, resulting in the largest and most elongate IVW. Accuracy predicted capture success, although other factors may also be important. The lower accuracy previously observed in M. salmoides was not replicated, but this is likely due to more natural conditions in our study. Additionally, we discuss the role of modulation and integrated behaviours in shaping the IVW and determining accuracy. With our model, accuracy is a more accessible performance measure for suction-feeding fishes, which can be used to explore macroevolutionary patterns of prey capture evolution. PMID:24718455

  17. A Solution Strategy to Include the Opening of the Opercular Slits in Moving-Mesh CFD Models of Suction Feeding.

    PubMed

    Van Wassenbergh, Sam

    2015-07-01

    The gill cover of fish and pre-metamorphic salamanders has a key role in suction feeding by acting as a one-way valve. It initially closes and avoids an inflow of water through the gill slits, after which it opens to allow outflow of the water that was sucked through the mouth into the expanded buccopharyngeal cavity. However, due to the inability of analytical models (relying on the continuity principle) to calculate the flow of fluid through a cavity with two openings and that was changing in shape and size, stringent boundary conditions had to be used in previously developed mathematical models after the moment of the valve's opening. By solving additionally for the conservation of momentum, computational fluid dynamics (CFD) has the capacity to dynamically simulate these flows, but this technique also faces complications in modeling a transition from closed to open valves. Here, I present a relatively simple solution strategy to incorporate the opening of the valves, exemplified in an axisymmetrical model of a suction-feeding sunfish in ANSYS Fluent software. By controlling viscosity of a separately defined fluid entity in the region of the opercular cavity, early inflow can be blocked (high viscosity assigned) and later outflow can be allowed (changing viscosity to that of water). Finally, by analyzing the CFD solution obtained for the sunfish model, a few new insights into the biomechanics of suction feeding are gained.

  18. Biomechanics and hydrodynamics of prey capture in the Chinese giant salamander reveal a high-performance jaw-powered suction feeding mechanism

    PubMed Central

    Heiss, Egon; Natchev, Nikolay; Gumpenberger, Michaela; Weissenbacher, Anton; Van Wassenbergh, Sam

    2013-01-01

    During the evolutionary transition from fish to tetrapods, a shift from uni- to bidirectional suction feeding systems followed a reduction in the gill apparatus. Such a shift can still be observed during metamorphosis of salamanders, although many adult salamanders retain their aquatic lifestyle and feed by high-performance suction. Unfortunately, little is known about the interplay between jaws and hyobranchial motions to generate bidirectional suction flows. Here, we study the cranial morphology, as well as kinematic and hydrodynamic aspects related to prey capture in the Chinese giant salamander (Andrias davidianus). Compared with fish and previously studied amphibians, A. davidianus uses an alternative suction mechanism that mainly relies on accelerating water by separating the ‘plates’ formed by the long and broad upper and lower jaw surfaces. Computational fluid dynamics simulations, based on three-dimensional morphology and kinematical data from high-speed videos, indicate that the viscerocranial elements mainly serve to accommodate the water that was given a sufficient anterior-to-posterior impulse beforehand by powerful jaw separation. We hypothesize that this modified way of generating suction is primitive for salamanders, and that this behaviour could have played an important role in the evolution of terrestrial life in vertebrates by releasing mechanical constraints on the hyobranchial system. PMID:23466557

  19. A Giant Chelonioid Turtle from the Late Cretaceous of Morocco with a Suction Feeding Apparatus Unique among Tetrapods

    PubMed Central

    Bardet, Nathalie; Jalil, Nour-Eddine; de Lapparent de Broin, France; Germain, Damien; Lambert, Olivier; Amaghzaz, Mbarek

    2013-01-01

    Background Secondary adaptation to aquatic life occurred independently in several amniote lineages, including reptiles during the Mesozoic and mammals during the Cenozoic. These evolutionary shifts to aquatic environments imply major morphological modifications, especially of the feeding apparatus. Mesozoic (250–65 Myr) marine reptiles, such as ichthyosaurs, plesiosaurs, mosasaurid squamates, crocodiles, and turtles, exhibit a wide range of adaptations to aquatic feeding and a broad overlap of their tooth morphospaces with those of Cenozoic marine mammals. However, despite these multiple feeding behavior convergences, suction feeding, though being a common feeding strategy in aquatic vertebrates and in marine mammals in particular, has been extremely rarely reported for Mesozoic marine reptiles. Principal Findings A relative of fossil protostegid and dermochelyoid sea turtles, Ocepechelon bouyai gen. et sp. nov. is a new giant chelonioid from the Late Maastrichtian (67 Myr) of Morocco exhibiting remarkable adaptations to marine life (among others, very dorsally and posteriorly located nostrils). The 70-cm-long skull of Ocepechelon not only makes it one of the largest marine turtles ever described, but also deviates significantly from typical turtle cranial morphology. It shares unique convergences with both syngnathid fishes (unique long tubular bony snout ending in a rounded and anteriorly directed mouth) and beaked whales (large size and elongated edentulous jaws). This striking anatomy suggests extreme adaptation for suction feeding unmatched among known turtles. Conclusion/Significance The feeding apparatus of Ocepechelon, a bony pipette-like snout, is unique among tetrapods. This new taxon exemplifies the successful systematic and ecological diversification of chelonioid turtles during the Late Cretaceous. This new evidence for a unique trophic specialization in turtles, along with the abundant marine vertebrate faunas associated to Ocepechelon in the Late

  20. Hydrodynamic starvation in first-feeding larval fishes

    PubMed Central

    China, Victor; Holzman, Roi

    2014-01-01

    Larval fishes suffer prodigious mortality rates, eliminating 99% of the brood within a few days after first feeding. Hjort (1914) famously attributed this “critical period” of low survival to the larvae’s inability to obtain sufficient food [Hjort (1914) Rapp P-v Réun Cons Int Explor Mer 20:1–228]. However, the cause of this poor feeding success remains to be identified. Here, we show that hydrodynamic constraints on the ubiquitous suction mechanism in first-feeding larvae limit their ability to capture prey, thereby reducing their feeding rates. Dynamic-scaling experiments revealed that larval size is the primary determinant of feeding rate, independent of other ontogenetic effects. We conclude that first-feeding larvae experience “hydrodynamic starvation,” in which low Reynolds numbers mechanistically limit their feeding performance even under high prey densities. Our results provide a hydrodynamic perspective on feeding of larval fishes that focuses on the physical properties of the larvae and prey, rather than on prey concentration and the rate of encounters. PMID:24843180

  1. Fish consumption and track to a fish feed formulation

    NASA Astrophysics Data System (ADS)

    Cai-Juan, Soong; Ramli, Razamin; Rahman, Rosshairy Abdul

    2015-12-01

    Strategically located in the equator, Malaysia is blessed with plenty of fish supply. The high demand in fish consumption has helped the development in the fishery industry and provided numerous jobs in the secondary sector, contributing significantly to the nation's income. A survey was conducted to understand the trend of current demands for fish for the purpose of designing a feed formulation, which is still limited in this area of study. Results showed that grouper fish in restaurants commanded a very high price compared to other species of fish. Tiger grouper gained the highest demand in most restaurants, while giant grouper had the highest price in restaurants. Due to the demand and challenges to culture this type of fish, a framework for fish feed formulation is proposed. The formulation framework when materialized could be an alternative to the use of trash fish as the feed for grouper.

  2. Time management and nectar flow: flower handling and suction feeding in long-proboscid flies (Nemestrinidae: Prosoeca)

    NASA Astrophysics Data System (ADS)

    Karolyi, Florian; Morawetz, Linde; Colville, Jonathan F.; Handschuh, Stephan; Metscher, Brian D.; Krenn, Harald W.

    2013-11-01

    A well-developed suction pump in the head represents an important adaptation for nectar-feeding insects, such as Hymenoptera, Lepidoptera and Diptera. This pumping organ creates a pressure gradient along the proboscis, which is responsible for nectar uptake. The extremely elongated proboscis of the genus Prosoeca (Nemestrinidae) evolved as an adaptation to feeding from long, tubular flowers. According to the functional constraint hypothesis, nectar uptake through a disproportionately elongated, straw-like proboscis increases flower handling time and consequently lowers the energy intake rate. Due to the conspicuous length variation of the proboscis of Prosoeca, individuals with longer proboscides are hypothesised to have longer handling times. To test this hypothesis, we used field video analyses of flower-visiting behaviour, detailed examinations of the suction pump morphology and correlations of proboscis length with body length and suction pump dimensions. Using a biomechanical framework described for nectar-feeding Lepidoptera in relation to proboscis length and suction pump musculature, we describe and contrast the system in long-proboscid flies. Flies with longer proboscides spent significantly more time drinking from flowers. In addition, proboscis length and body length showed a positive allometric relationship. Furthermore, adaptations of the suction pump included an allometric relationship between proboscis length and suction pump muscle volume and a combination of two pumping organs. Overall, the study gives detailed insight into the adaptations required for long-proboscid nectar feeding, and comparisons with other nectar-sucking insects allow further considerations of the evolution of the suction pump in insects with sucking mouthparts.

  3. Feeding Practices and Fish Health

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Over the past three decades, the aquaculture industry has expanded rapidly throughout the world and is expected to continue to grow in the years to come due to the unpredictability and high cost of harvesting fish from the oceans as well as the increased demand for fish as a result of rapid populati...

  4. Australian Fur Seals (Arctocephalus pusillus doriferus) Use Raptorial Biting and Suction Feeding When Targeting Prey in Different Foraging Scenarios

    PubMed Central

    Hocking, David P.; Salverson, Marcia; Fitzgerald, Erich M. G.; Evans, Alistair R.

    2014-01-01

    Foraging behaviours used by two female Australian fur seals (Arctocephalus pusillus doriferus) were documented during controlled feeding trials. During these trials the seals were presented with prey either free-floating in open water or concealed within a mobile ball or a static box feeding device. When targeting free-floating prey both subjects primarily used raptorial biting in combination with suction, which was used to draw prey to within range of the teeth. When targeting prey concealed within either the mobile or static feeding device, the seals were able to use suction to draw out prey items that could not be reached by biting. Suction was followed by lateral water expulsion, where water drawn into the mouth along with the prey item was purged via the sides of the mouth. Vibrissae were used to explore the surface of the feeding devices, especially when locating the openings in which the prey items had been hidden. The mobile ball device was also manipulated by pushing it with the muzzle to knock out concealed prey, which was not possible when using the static feeding device. To knock prey out of this static device one seal used targeted bubble blowing, where a focused stream of bubbles was blown out of the nose into the openings in the device. Once captured in the jaws, prey items were manipulated and re-oriented using further mouth movements or chews so that they could be swallowed head first. While most items were swallowed whole underwater, some were instead taken to the surface and held in the teeth, while being vigorously shaken to break them into smaller pieces before swallowing. The behavioural flexibility displayed by Australian fur seals likely assists in capturing and consuming the extremely wide range of prey types that are targeted in the wild, during both benthic and epipelagic foraging. PMID:25390347

  5. Australian fur seals (Arctocephalus pusillus doriferus) use raptorial biting and suction feeding when targeting prey in different foraging scenarios.

    PubMed

    Hocking, David P; Salverson, Marcia; Fitzgerald, Erich M G; Evans, Alistair R

    2014-01-01

    Foraging behaviours used by two female Australian fur seals (Arctocephalus pusillus doriferus) were documented during controlled feeding trials. During these trials the seals were presented with prey either free-floating in open water or concealed within a mobile ball or a static box feeding device. When targeting free-floating prey both subjects primarily used raptorial biting in combination with suction, which was used to draw prey to within range of the teeth. When targeting prey concealed within either the mobile or static feeding device, the seals were able to use suction to draw out prey items that could not be reached by biting. Suction was followed by lateral water expulsion, where water drawn into the mouth along with the prey item was purged via the sides of the mouth. Vibrissae were used to explore the surface of the feeding devices, especially when locating the openings in which the prey items had been hidden. The mobile ball device was also manipulated by pushing it with the muzzle to knock out concealed prey, which was not possible when using the static feeding device. To knock prey out of this static device one seal used targeted bubble blowing, where a focused stream of bubbles was blown out of the nose into the openings in the device. Once captured in the jaws, prey items were manipulated and re-oriented using further mouth movements or chews so that they could be swallowed head first. While most items were swallowed whole underwater, some were instead taken to the surface and held in the teeth, while being vigorously shaken to break them into smaller pieces before swallowing. The behavioural flexibility displayed by Australian fur seals likely assists in capturing and consuming the extremely wide range of prey types that are targeted in the wild, during both benthic and epipelagic foraging.

  6. Australian fur seals (Arctocephalus pusillus doriferus) use raptorial biting and suction feeding when targeting prey in different foraging scenarios.

    PubMed

    Hocking, David P; Salverson, Marcia; Fitzgerald, Erich M G; Evans, Alistair R

    2014-01-01

    Foraging behaviours used by two female Australian fur seals (Arctocephalus pusillus doriferus) were documented during controlled feeding trials. During these trials the seals were presented with prey either free-floating in open water or concealed within a mobile ball or a static box feeding device. When targeting free-floating prey both subjects primarily used raptorial biting in combination with suction, which was used to draw prey to within range of the teeth. When targeting prey concealed within either the mobile or static feeding device, the seals were able to use suction to draw out prey items that could not be reached by biting. Suction was followed by lateral water expulsion, where water drawn into the mouth along with the prey item was purged via the sides of the mouth. Vibrissae were used to explore the surface of the feeding devices, especially when locating the openings in which the prey items had been hidden. The mobile ball device was also manipulated by pushing it with the muzzle to knock out concealed prey, which was not possible when using the static feeding device. To knock prey out of this static device one seal used targeted bubble blowing, where a focused stream of bubbles was blown out of the nose into the openings in the device. Once captured in the jaws, prey items were manipulated and re-oriented using further mouth movements or chews so that they could be swallowed head first. While most items were swallowed whole underwater, some were instead taken to the surface and held in the teeth, while being vigorously shaken to break them into smaller pieces before swallowing. The behavioural flexibility displayed by Australian fur seals likely assists in capturing and consuming the extremely wide range of prey types that are targeted in the wild, during both benthic and epipelagic foraging. PMID:25390347

  7. A biorobotic model of the suction-feeding system in largemouth bass: the roles of motor program speed and hyoid kinematics.

    PubMed

    Kenaley, Christopher P; Lauder, George V

    2016-07-01

    The vast majority of ray-finned fishes capture prey through suction feeding. The basis of this behavior is the generation of subambient pressure through rapid expansion of a highly kinetic skull. Over the last four decades, results from in vivo experiments have elucidated the general relationships between morphological parameters and subambient pressure generation. Until now, however, researchers have been unable to tease apart the discrete contributions of, and complex relationships among, the musculoskeletal elements that support buccal expansion. Fortunately, over the last decade, biorobotic models have gained a foothold in comparative research and show great promise in addressing long-standing questions in vertebrate biomechanics. In this paper, we present BassBot, a biorobotic model of the head of the largemouth bass (Micropterus salmoides). BassBot incorporates a 3D acrylic plastic armature of the neurocranium, maxillary apparatus, lower jaw, hyoid, suspensorium and opercular apparatus. Programming of linear motors permits precise reproduction of live kinematic behaviors including hyoid depression and rotation, premaxillary protrusion, and lateral expansion of the suspensoria. BassBot reproduced faithful kinematic and pressure dynamics relative to live bass. We show that motor program speed has a direct relationship to subambient pressure generation. Like vertebrate muscle, the linear motors that powered kinematics were able to produce larger magnitudes of force at slower velocities and, thus, were able to accelerate linkages more quickly and generate larger magnitudes of subambient pressure. In addition, we demonstrate that disrupting the kinematic behavior of the hyoid interferes with the anterior-to-posterior expansion gradient. This resulted in a significant reduction in subambient pressure generation and pressure impulse of 51% and 64%, respectively. These results reveal the promise biorobotic models have for isolating individual parameters and assessing

  8. A biorobotic model of the suction-feeding system in largemouth bass: the roles of motor program speed and hyoid kinematics.

    PubMed

    Kenaley, Christopher P; Lauder, George V

    2016-07-01

    The vast majority of ray-finned fishes capture prey through suction feeding. The basis of this behavior is the generation of subambient pressure through rapid expansion of a highly kinetic skull. Over the last four decades, results from in vivo experiments have elucidated the general relationships between morphological parameters and subambient pressure generation. Until now, however, researchers have been unable to tease apart the discrete contributions of, and complex relationships among, the musculoskeletal elements that support buccal expansion. Fortunately, over the last decade, biorobotic models have gained a foothold in comparative research and show great promise in addressing long-standing questions in vertebrate biomechanics. In this paper, we present BassBot, a biorobotic model of the head of the largemouth bass (Micropterus salmoides). BassBot incorporates a 3D acrylic plastic armature of the neurocranium, maxillary apparatus, lower jaw, hyoid, suspensorium and opercular apparatus. Programming of linear motors permits precise reproduction of live kinematic behaviors including hyoid depression and rotation, premaxillary protrusion, and lateral expansion of the suspensoria. BassBot reproduced faithful kinematic and pressure dynamics relative to live bass. We show that motor program speed has a direct relationship to subambient pressure generation. Like vertebrate muscle, the linear motors that powered kinematics were able to produce larger magnitudes of force at slower velocities and, thus, were able to accelerate linkages more quickly and generate larger magnitudes of subambient pressure. In addition, we demonstrate that disrupting the kinematic behavior of the hyoid interferes with the anterior-to-posterior expansion gradient. This resulted in a significant reduction in subambient pressure generation and pressure impulse of 51% and 64%, respectively. These results reveal the promise biorobotic models have for isolating individual parameters and assessing

  9. Fishing for feed or fishing for food: increasing global competition for small pelagic forage fish.

    PubMed

    Tacon, Albert G J; Metian, Marc

    2009-09-01

    At present, small pelagic forage fish species (includes anchovies, herring, mackerel, sardines, etc.) represent the largest landed species group in capture fisheries (27.3 million t or 29.7% of total capture fisheries landings in 2006). They also currently constitute the major species group actively fished and targeted for nonfood uses, including reduction into fishmeal and fish oil for use within compound animal feeds, or for direct animal feeding; the aquaculture sector alone consumed the equivalent of about 23.8 million t of fish (live weight equivalent) or 87% in the form of feed inputs in 2006. This article attempts to make a global analysis of the competition for small pelagic forage fish for direct human consumption and nonfood uses, particularly concerning the important and growing role played by small pelagic forage fish in the diet and food security of the poor and needy, especially within the developing countries of Africa and the Sub-Saharan region.

  10. Raising the Sugar Content – Orchid Bees Overcome the Constraints of Suction Feeding through Manipulation of Nectar and Pollen Provisions

    PubMed Central

    Pokorny, Tamara; Lunau, Klaus; Eltz, Thomas

    2014-01-01

    Unlike most other bees, the long-tongued orchid bees ingest nectar using suction feeding. Although long tongues allow exploitation of flowers with deep spurs, the energy intake rate is optimal at 10–20% lower nectar sugar concentrations compared to that of lapping bees. This constraint might be compensated by a higher digestive throughput. Additionally, orchid bees might evaporate water from regurgitated droplets of crop contents. We found male Euglossa championi (n = 10) and Euglossa dodsoni (n = 12) to regularly regurgitate droplets of crop content to the base of their proboscis, generating a fluid film between the proximal parts of the galeae, glossa and labial palps. Rhythmic movements of the proboscis may help to increase convection. There was a significant change in sugar concentration between the initially imbibed solution and the resulting crop content (P<0.05) and the time individual bees had engaged in this liquid exposure behavior was positively correlated with the resulting crop sugar concentration. Female Euglossa townsendi and Euglossa viridissima showed the same behavior. Additionally, they manipulated their nectar-enriched pollen provisions for extensive periods of time before deposition in brood cells. The deposited pollen loads (n = 14) showed a significantly higher sugar concentration than the sugar-water available to the bees (P<0.001). Thus, both male and female euglossines show behaviors that promote evaporative water loss from nectar. We suggest that the behaviors have evolved in concert with suction feeding on dilute nectar from deep floral tubes. PMID:25422945

  11. New fossil insect order Permopsocida elucidates major radiation and evolution of suction feeding in hemimetabolous insects (Hexapoda: Acercaria)

    PubMed Central

    Huang, Di-Ying; Bechly, Günter; Nel, Patricia; Engel, Michael S.; Prokop, Jakub; Azar, Dany; Cai, Chen-Yang; van de Kamp, Thomas; Staniczek, Arnold H.; Garrouste, Romain; Krogmann, Lars; dos Santos Rolo, Tomy; Baumbach, Tilo; Ohlhoff, Rainer; Shmakov, Alexey S.; Bourgoin, Thierry; Nel, André

    2016-01-01

    With nearly 100,000 species, the Acercaria (lice, plant lices, thrips, bugs) including number of economically important species is one of the most successful insect lineages. However, its phylogeny and evolution of mouthparts among other issues remain debatable. Here new methods of preparation permitted the comprehensive anatomical description of insect inclusions from mid-Cretaceous Burmese amber in astonishing detail. These “missing links” fossils, attributed to a new order Permopsocida, provide crucial evidence for reconstructing the phylogenetic relationships in the Acercaria, supporting its monophyly, and questioning the position of Psocodea as sister group of holometabolans in the most recent phylogenomic study. Permopsocida resolves as sister group of Thripida + Hemiptera and represents an evolutionary link documenting the transition from chewing to piercing mouthparts in relation to suction feeding. Identification of gut contents as angiosperm pollen documents an ecological role of Permopsocida as early pollen feeders with relatively unspecialized mouthparts. This group existed for 185 million years, but has never been diverse and was superseded by new pollenivorous pollinators during the Cretaceous co-evolution of insects and flowers. The key innovation of suction feeding with piercing mouthparts is identified as main event that triggered the huge post-Carboniferous radiation of hemipterans, and facilitated the spreading of pathogenic vectors. PMID:26961785

  12. Raising the sugar content--orchid bees overcome the constraints of suction feeding through manipulation of nectar and pollen provisions.

    PubMed

    Pokorny, Tamara; Lunau, Klaus; Eltz, Thomas

    2014-01-01

    Unlike most other bees, the long-tongued orchid bees ingest nectar using suction feeding. Although long tongues allow exploitation of flowers with deep spurs, the energy intake rate is optimal at 10-20% lower nectar sugar concentrations compared to that of lapping bees. This constraint might be compensated by a higher digestive throughput. Additionally, orchid bees might evaporate water from regurgitated droplets of crop contents. We found male Euglossa championi (n = 10) and Euglossa dodsoni (n = 12) to regularly regurgitate droplets of crop content to the base of their proboscis, generating a fluid film between the proximal parts of the galeae, glossa and labial palps. Rhythmic movements of the proboscis may help to increase convection. There was a significant change in sugar concentration between the initially imbibed solution and the resulting crop content (P<0.05) and the time individual bees had engaged in this liquid exposure behavior was positively correlated with the resulting crop sugar concentration. Female Euglossa townsendi and Euglossa viridissima showed the same behavior. Additionally, they manipulated their nectar-enriched pollen provisions for extensive periods of time before deposition in brood cells. The deposited pollen loads (n = 14) showed a significantly higher sugar concentration than the sugar-water available to the bees (P<0.001). Thus, both male and female euglossines show behaviors that promote evaporative water loss from nectar. We suggest that the behaviors have evolved in concert with suction feeding on dilute nectar from deep floral tubes.

  13. New fossil insect order Permopsocida elucidates major radiation and evolution of suction feeding in hemimetabolous insects (Hexapoda: Acercaria).

    PubMed

    Huang, Di-Ying; Bechly, Günter; Nel, Patricia; Engel, Michael S; Prokop, Jakub; Azar, Dany; Cai, Chen-Yang; van de Kamp, Thomas; Staniczek, Arnold H; Garrouste, Romain; Krogmann, Lars; Dos Santos Rolo, Tomy; Baumbach, Tilo; Ohlhoff, Rainer; Shmakov, Alexey S; Bourgoin, Thierry; Nel, André

    2016-01-01

    With nearly 100,000 species, the Acercaria (lice, plant lices, thrips, bugs) including number of economically important species is one of the most successful insect lineages. However, its phylogeny and evolution of mouthparts among other issues remain debatable. Here new methods of preparation permitted the comprehensive anatomical description of insect inclusions from mid-Cretaceous Burmese amber in astonishing detail. These "missing links" fossils, attributed to a new order Permopsocida, provide crucial evidence for reconstructing the phylogenetic relationships in the Acercaria, supporting its monophyly, and questioning the position of Psocodea as sister group of holometabolans in the most recent phylogenomic study. Permopsocida resolves as sister group of Thripida + Hemiptera and represents an evolutionary link documenting the transition from chewing to piercing mouthparts in relation to suction feeding. Identification of gut contents as angiosperm pollen documents an ecological role of Permopsocida as early pollen feeders with relatively unspecialized mouthparts. This group existed for 185 million years, but has never been diverse and was superseded by new pollenivorous pollinators during the Cretaceous co-evolution of insects and flowers. The key innovation of suction feeding with piercing mouthparts is identified as main event that triggered the huge post-Carboniferous radiation of hemipterans, and facilitated the spreading of pathogenic vectors. PMID:26961785

  14. Suction is kid's play: extremely fast suction in newborn seahorses.

    PubMed

    Van Wassenbergh, Sam; Roos, Gert; Genbrugge, Annelies; Leysen, Heleen; Aerts, Peter; Adriaens, Dominique; Herrel, Anthony

    2009-04-23

    Ongoing anatomical development typically results in a gradual maturation of the feeding movements from larval to adult fishes. Adult seahorses are known to capture prey by rotating their long-snouted head extremely quickly towards prey, followed by powerful suction. This type of suction is powered by elastic recoil and requires very precise coordination of the movements of the associated feeding structures, making it an all-or-none phenomenon. Here, we show that newborn Hippocampus reidi are able to successfully feed using an extremely rapid and powerful snout rotation combined with a high-volume suction, surpassing that observed in adult seahorses. An inverse dynamic analysis shows that an elastic recoil mechanism is also used to power head rotation in newborn H. reidi. This illustrates how extreme levels of performance in highly complex musculoskeletal systems can be present at birth given a delayed birth and rapid development of functionally important structures. The fact that the head skeleton of newborn seahorses is still largely cartilaginous may not be problematic because the hydrodynamic stress on the rotating snout appeared considerably lower than in adult syngnathids.

  15. PCBs and DDE in commercial fish feeds

    USGS Publications Warehouse

    Mac, Michael J.; Nicholson, L.W.; McCauley, C.A.

    1979-01-01

    Three commercial fish feeds were analyzed for PCBs and p,p' DDE and were reported in dry weight concentrations. In various sizes of Oregon Moist Pellets, concentrations of PCBs ranged from less than 0.10 to 0.30 I?g/g and those of p,p' DDE from less than 0.01 to 0.47 I?g/g. In Silver Cup, concentrations of PCBs were 0.06 to 0.07 I?g/g, and p,p' DDE, 0.01 to 0.06 I?g/g. Nauplii of brine shrimp (Artemia salina) contained 0.14 I?g/g PCB and 0.03 I?g/g p,p' DDE.

  16. A fish that uses its hydrodynamic tongue to feed on land

    PubMed Central

    Michel, Krijn B.; Heiss, Egon; Aerts, Peter; Van Wassenbergh, Sam

    2015-01-01

    To capture and swallow food on land, a sticky tongue supported by the hyoid and gill arch skeleton has evolved in land vertebrates from aquatic ancestors that used mouth-cavity-expanding actions of the hyoid to suck food into the mouth. However, the evolutionary pathway bridging this drastic shift in feeding mechanism and associated hyoid motions remains unknown. Modern fish that feed on land may help to unravel the physical constraints and biomechanical solutions that led to terrestrialization of fish-feeding systems. Here, we show that the mudskipper emerges onto land with its mouth cavity filled with water, which it uses as a protruding and retracting ‘hydrodynamic tongue’ during the initial capture and subsequent intra-oral transport of food. Our analyses link this hydrodynamic action of the intra-oral water to a sequence of compressive and expansive cranial motions that diverge from the general pattern known for suction feeding in fishes. However, the hyoid motion pattern showed a remarkable resemblance to newts during tongue prehension. Consequently, although alternative scenarios cannot be excluded, hydrodynamic tongue usage may be a transitional step onto which the evolution of adhesive mucosa and intrinsic lingual muscles can be added to gain further independence from water for terrestrial foraging. PMID:25788596

  17. A fish that uses its hydrodynamic tongue to feed on land.

    PubMed

    Michel, Krijn B; Heiss, Egon; Aerts, Peter; Van Wassenbergh, Sam

    2015-04-22

    To capture and swallow food on land, a sticky tongue supported by the hyoid and gill arch skeleton has evolved in land vertebrates from aquatic ancestors that used mouth-cavity-expanding actions of the hyoid to suck food into the mouth. However, the evolutionary pathway bridging this drastic shift in feeding mechanism and associated hyoid motions remains unknown. Modern fish that feed on land may help to unravel the physical constraints and biomechanical solutions that led to terrestrialization of fish-feeding systems. Here, we show that the mudskipper emerges onto land with its mouth cavity filled with water, which it uses as a protruding and retracting 'hydrodynamic tongue' during the initial capture and subsequent intra-oral transport of food. Our analyses link this hydrodynamic action of the intra-oral water to a sequence of compressive and expansive cranial motions that diverge from the general pattern known for suction feeding in fishes. However, the hyoid motion pattern showed a remarkable resemblance to newts during tongue prehension. Consequently, although alternative scenarios cannot be excluded, hydrodynamic tongue usage may be a transitional step onto which the evolution of adhesive mucosa and intrinsic lingual muscles can be added to gain further independence from water for terrestrial foraging.

  18. Liparid and macrourid fishes of the hadal zone: in situ observations of activity and feeding behaviour

    PubMed Central

    Jamieson, A.J.; Fujii, T.; Solan, M.; Matsumoto, A.K.; Bagley, P.M.; Priede, I.G.

    2008-01-01

    Using baited camera landers, the first images of living fishes were recorded in the hadal zone (6000–11 000 m) in the Pacific Ocean. The widespread abyssal macrourid Coryphaenoides yaquinae was observed at a new depth record of approximately 7000 m in the Japan Trench. Two endemic species of liparid were observed at similar depths: Pseudoliparis amblystomopsis in the Japan Trench and Notoliparis kermadecensis in the Kermadec Trench. From these observations, we have documented swimming and feeding behaviour of these species and derived the first estimates of hadal fish abundance. The liparids intercepted bait within 100–200 min but were observed to preferentially feed on scavenging amphipods. Notoliparis kermadecensis act as top predators in the hadal food web, exhibiting up to nine suction-feeding events per minute. Both species showed distinctive swimming gaits: P. amblystomopsis (mean length 22.5 cm) displayed a mean tail-beat frequency of 0.47 Hz and mean caudal : pectoral frequency ratio of 0.76, whereas N. kermadecensis (mean length 31.5 cm) displayed respective values of 1.04 and 2.08 Hz. Despite living at extreme depths, these endemic liparids exhibit similar activity levels compared with shallow-water liparids. PMID:19129104

  19. Liparid and macrourid fishes of the hadal zone: in situ observations of activity and feeding behaviour.

    PubMed

    Jamieson, A J; Fujii, T; Solan, M; Matsumoto, A K; Bagley, P M; Priede, I G

    2009-03-22

    Using baited camera landers, the first images of living fishes were recorded in the hadal zone (6000-11000 m) in the Pacific Ocean. The widespread abyssal macrourid Coryphaenoides yaquinae was observed at a new depth record of approximately 7000 m in the Japan Trench. Two endemic species of liparid were observed at similar depths: Pseudoliparis amblystomopsis in the Japan Trench and Notoliparis kermadecensis in the Kermadec Trench. From these observations, we have documented swimming and feeding behaviour of these species and derived the first estimates of hadal fish abundance. The liparids intercepted bait within 100-200 min but were observed to preferentially feed on scavenging amphipods. Notoliparis kermadecensis act as top predators in the hadal food web, exhibiting up to nine suction-feeding events per minute. Both species showed distinctive swimming gaits: P. amblystomopsis (mean length 22.5 cm) displayed a mean tail-beat frequency of 0.47 Hz and mean caudal:pectoral frequency ratio of 0.76, whereas N. kermadecensis (mean length 31.5 cm) displayed respective values of 1.04 and 2.08 Hz. Despite living at extreme depths, these endemic liparids exhibit similar activity levels compared with shallow-water liparids. PMID:19129104

  20. Liparid and macrourid fishes of the hadal zone: in situ observations of activity and feeding behaviour.

    PubMed

    Jamieson, A J; Fujii, T; Solan, M; Matsumoto, A K; Bagley, P M; Priede, I G

    2009-03-22

    Using baited camera landers, the first images of living fishes were recorded in the hadal zone (6000-11000 m) in the Pacific Ocean. The widespread abyssal macrourid Coryphaenoides yaquinae was observed at a new depth record of approximately 7000 m in the Japan Trench. Two endemic species of liparid were observed at similar depths: Pseudoliparis amblystomopsis in the Japan Trench and Notoliparis kermadecensis in the Kermadec Trench. From these observations, we have documented swimming and feeding behaviour of these species and derived the first estimates of hadal fish abundance. The liparids intercepted bait within 100-200 min but were observed to preferentially feed on scavenging amphipods. Notoliparis kermadecensis act as top predators in the hadal food web, exhibiting up to nine suction-feeding events per minute. Both species showed distinctive swimming gaits: P. amblystomopsis (mean length 22.5 cm) displayed a mean tail-beat frequency of 0.47 Hz and mean caudal:pectoral frequency ratio of 0.76, whereas N. kermadecensis (mean length 31.5 cm) displayed respective values of 1.04 and 2.08 Hz. Despite living at extreme depths, these endemic liparids exhibit similar activity levels compared with shallow-water liparids.

  1. Mercury and stable isotope signatures in caged marine fish and fish feeds.

    PubMed

    Onsanit, Sarayut; Chen, Min; Ke, Caihuan; Wang, Wen-Xiong

    2012-02-15

    Total mercury (THg) and methylmercury (MeHg) concentrations were determined in four species of marine caged carnivorous fish, one species of herbivorous fish and three types of fish feeds (dried pellet feed, forage fish and fish viscera), collected from five cage sites in the rural areas along Fujian coastline, China. For the carnivorous fish, the concentrations of THg and MeHg ranged from 0.03 to 0.31 μg/g and from 0.02 to 0.30 μg/g on wet weight basis, respectively. The concentrations were lower for the herbivorous fish with both within the range of 0.01-0.03 μg/g. Out of the three tested fish feeds, tuna viscera contained the highest level of mercury (0.20 μg/g THg and 0.13 μg/g MeHg), with pellet feed containing the lowest level (0.05 μg/g THg and 0.01 μg/g MeHg). The calculated trophic transfer factor of MeHg was the highest (12-64) for fish fed on pellet feeds, and was the lowest for fish fed on tuna viscera. A significant relationship was found between Hg concentrations in caged fish and in fish feeds, thus Hg was primarily accumulated from the diet. Furthermore, the stable isotope δ(15)N was positively correlated with the Hg concentration in two caged sites, indicating that δ(15)N may be a suitable tool for tracking mercury in caged fish. We conclude that fish farming may be a good way of reducing the human exposure to Hg because mercury levels can be carefully controlled in such farming systems. PMID:22195524

  2. [Detection of fish DNA in ruminant feed by PCR amplification].

    PubMed

    Nomura, Tetsuya; Kusama, Toyoko; Kadowaki, Koh-ichi

    2006-10-01

    The Japanese Government has prohibited the use of seafood protein, as well as mammalian protein, in ruminant feed. There is an official method to detect meat and bone meal, but no method is yet available to detect fishmeal in ruminant feed. We tried to develop a suitable method to detect fishmeal in ruminant feed, similar to the official method "PCR detection of animal-derived DNA in feed". Our previously reported primers (fishcon5 and fishcon3-1) showed low sensitivity, so we designed new primers based on a DNA sequence from yellowfin tuna mitchondrial DNA. Among the primers, FM5 and FM3 specifically detected fish DNA (sardine, yellowfin tuna, skipjack tuna, chub mackerel, Pacific saury, salmon, rainbow trout, Japanese anchovy, codfish and Japanese horse mackerel) from fish meat, and did not amplify DNA from animals and plants. The sensitivity for detection of the presence of fishmeal in ruminant feed was 0.01-0.001%. PMID:17128872

  3. Analysis of persistent halogenated hydrocarbons in fish feeds containing fish oil and other alternative lipid sources.

    PubMed

    You, Jing; Kelley, Rebecca A; Crouse, Curtis C; Trushenski, Jesse T; Lydy, Michael J

    2011-09-15

    A trade-off exists between beneficial n-3 long-chain polyunsaturated acids and toxic persistent halogenated hydrocarbons (PHHs), both of which primarily originate from fish oil commonly used in fish feeds. Alternative lipid sources are being investigated for use in fish feeds to reduce harmful contaminant accumulation, hence, research is needed to evaluate PHHs in fish feeds with various lipid compositions. An analytical method was developed for PHHs including nine organochlorine insecticides (OCPs), 26 polychlorinated biphenyls (PCBs) and seven polybrominated diphenyl ethers (PBDEs) in fish feeds with differing proportions of fish oils and alternative lipid sources by GC-ECD after accelerated solvent extraction, gel permeation chromatography (GPC), and sulfuric acid cleanup. The GPC removed the majority of the neutral lipids and sulfuric acid treatment effectively destroyed the polar lipids. Thus, the combination of the two methods removed approximately 99.7% of the lipids in the extracts. The method detection limits were less than 5 ng/g dry weight (dw) for most PHHs, while recoveries were 75-118%, 67-105%, 69-92%, 63-100% and 94-144% with relative standard deviations of 0.2-39%, 0.3-20%, 0.5-12%, 1.5-18% and 1.5-15% for PHHs in five types of fish feeds made from different lipid sources. Although the source of lipid showed no impact on cleanup efficiency and the developed method worked well for all feeds, fish feeds with 100% fish oil contained background PHHs and more interference than feeds containing alternative lipids.

  4. [Selective feeding in fish: Effect of feeding and defensive motivations evoked by natural odors].

    PubMed

    Kasumyan, A O; Marusov, E A

    2015-01-01

    The effect of feeding and defensive motivations evoked by natural olfactory signals (the food odor, the alarm pheromone) on choice and consumption of food items different in color and taste, and the manifestation of foraging behavior were examined in fish (koi Cyprinus carpio, roach Rutilus rutilus). The agar-agar pellets of red and green color having one of the amino acids (glycine, L-proline, L-alanine; all in concentration of 0.1 M) were simultaneously offered to single fishes in pure water, and in water extract of Chironomidae larvae or in water extract of fish skin. It was found out that odors used have different effects on fish foraging activity and on pellet selection for both pellet choice and consumption. On background of food odor, fish grasped pellets more often than in pure water. The equal choice of red and green pellets in pure water shifted to the preference of red ones in the presence of food odor. Despite the increase in the absolute number of pellets grasped, the relative consumption reduced and was replaced by selective consumption of pellets with glycine regardless of their color. Increasing demand for the food quality, due to the increased feeding motivation in response to food odor, is an important adaptation enhancing selection and consumption of food with more appropriate sensory qualities for fish. Defensive motivation caused by alarm pheromone suppressed predisposition. of fish to feed. Fish grasped pellets several times less often than in pure water and refused most of them. Any changes in the color or taste preferences were absent. Feeding behavior of fish of both species was characterized by repeated intraoral pellet testing, but in koi handling was less typical than in roach. In both species, handling activity was higher in those cases when the pellet was finally rejected. This activity was enhanced also on the background of food odor. PMID:26201217

  5. [Selective feeding in fish: Effect of feeding and defensive motivations evoked by natural odors].

    PubMed

    Kasumyan, A O; Marusov, E A

    2015-01-01

    The effect of feeding and defensive motivations evoked by natural olfactory signals (the food odor, the alarm pheromone) on choice and consumption of food items different in color and taste, and the manifestation of foraging behavior were examined in fish (koi Cyprinus carpio, roach Rutilus rutilus). The agar-agar pellets of red and green color having one of the amino acids (glycine, L-proline, L-alanine; all in concentration of 0.1 M) were simultaneously offered to single fishes in pure water, and in water extract of Chironomidae larvae or in water extract of fish skin. It was found out that odors used have different effects on fish foraging activity and on pellet selection for both pellet choice and consumption. On background of food odor, fish grasped pellets more often than in pure water. The equal choice of red and green pellets in pure water shifted to the preference of red ones in the presence of food odor. Despite the increase in the absolute number of pellets grasped, the relative consumption reduced and was replaced by selective consumption of pellets with glycine regardless of their color. Increasing demand for the food quality, due to the increased feeding motivation in response to food odor, is an important adaptation enhancing selection and consumption of food with more appropriate sensory qualities for fish. Defensive motivation caused by alarm pheromone suppressed predisposition. of fish to feed. Fish grasped pellets several times less often than in pure water and refused most of them. Any changes in the color or taste preferences were absent. Feeding behavior of fish of both species was characterized by repeated intraoral pellet testing, but in koi handling was less typical than in roach. In both species, handling activity was higher in those cases when the pellet was finally rejected. This activity was enhanced also on the background of food odor.

  6. Occurrence of PCDD/F, PCB, PBDE, PFAS, and organotin compounds in fish meal, fish oil and fish feed.

    PubMed

    Suominen, K; Hallikainen, A; Ruokojärvi, P; Airaksinen, R; Koponen, J; Rannikko, R; Kiviranta, H

    2011-10-01

    We analysed polychlorinated dibenzo-p-dioxins and furans (PCDD/F, dioxins), and polychlorinated biphenyls (PCB) in 13 fish meal, five fish oil, and seven fish feed samples. Polybrominated diphenyl ethers (PBDE), organotin compounds (OTC), and perfluoroalkylated substances (PFAS) were analysed in ten fish meal, two fish oil, and two fish feed samples. All measured TEQ concentrations of PCDD/F and PCB were below the maximum levels set by Directive 2002/32/EC. There was no correlation between concentrations of WHOPCDD/F-TEQ and indicator PCB in our samples. The most common congeners among PBDEs were BDE-47 and BDE-100. BDE-209 was present in five fish meals of the ten analysed. Tributyltin (TBT) was the predominant congener in all samples except in three fish meals, where monobutyltin (MBT) was the major congener. Perfluorooctane sulphonate (PFOS) was the predominant congener in six fish meals of the ten analysed. There was large variation in concentrations and congener distributions of the studied compounds between our samples. Our results underline a need to pay special attention to the origin and purity of feed raw material of marine origin.

  7. Suction, Ram, and Biting: Deviations and Limitations to the Capture of Aquatic Prey.

    PubMed

    Ferry, Lara A; Paig-Tran, E Misty; Gibb, Alice C

    2015-07-01

    When feeding, most aquatic organisms generate suction that draws prey into the mouth. The papers in this volume are a demonstration of this fact. However, under what circumstances is suction ineffective as a feeding mechanism? Here we consider the interplay between suction, ram, and biting, and analyze the contribution of each to the capture of prey by a wide variety of species of fish. We find, not surprisingly, that ram is the dominant contributor to feeding because suction, and biting, are only effective when very close to the prey. As species utilize more strongly ram-dominated modes of feeding, they may be released from the morphological and behavioral constraints associated with the need to direct a current of water into the head. Morphological and behavioral changes that facilitate larger gapes and stronger jaws are explored here, including predators that lack a protrusile upper jaw, predators with elongate jaws, predators that rely on suspension feeding, and predators that bite. Interestingly, while the mobility of the jaws and the shape of the opening of the mouth are modified in species that have departed from a primary reliance on suction feeding, the anterior-to-posterior wave of expansion persists. This wave may be greatly slowed in ram and biting species, but its retention suggests a fundamental importance to aquatic feeding.

  8. Feeding diets and significance of coral feeding among Chaetodontid fishes in Moorea (French Polynesia)

    NASA Astrophysics Data System (ADS)

    Harmelin-Vivien, M. L.; Bouchon-Navaro, Y.

    1983-06-01

    The feeding diets of 18 Chaetodontid fishes from a coral reef of Moorea (French Polynesia) were studied by quantitative analysis of their stomach contents. Three major types of feeding behaviours were distinguished. Sixteen species essentially ingested coral polyps. Among these species, 5 were exclusive coral browsers and the others displayed more heterogeneous diets. One species was a plankton feeder and the other consumed benthic invertebrates other than corals. The importance of coral consumption on the reef by Chaetodontid fishes was estimated knowing the feeding diets and density of species in the various biota. Moreover, the species which were previously observed as quantitatively dominant in the different reef zones, were found to be exclusive coral browsers. Besides, the proportion between obligative and facultative coral feeders was found to be relatively constant on the reef, emphasizing that a balance is established among the Chaetodontid species occupying the same habitat for the resource partitioning.

  9. Effects of bottom trawling on fish foraging and feeding

    PubMed Central

    Johnson, Andrew Frederick; Gorelli, Giulia; Jenkins, Stuart Rees; Hiddink, Jan Geert; Hinz, Hilmar

    2015-01-01

    The effects of bottom trawling on benthic invertebrates include reductions of biomass, diversity and body size. These changes may negatively affect prey availability for demersal fishes, potentially leading to reduced food intake, body condition and yield of fishes in chronically trawled areas. Here, the effect of trawling on the prey availability and diet of two commercially important flatfish species, plaice (Pleuronectes platessa) and dab (Limanda limanda), was investigated over a trawling intensity gradient in the Irish Sea. Previous work in this area has shown that trawling negatively affects the condition of plaice but not of dab. This study showed that reductions in local prey availability did not result in reduced feeding of fish. As trawling frequency increased, both fish and prey biomass declined, such that the ratio of fish to prey remained unchanged. Consequently, even at frequently trawled sites with low prey biomass, both plaice and dab maintained constant levels of stomach fullness and gut energy contents. However, dietary shifts in plaice towards energy-poor prey items were evident when prey species were analysed individually. This, together with a potential decrease in foraging efficiency due to low prey densities, was seen as the most plausible cause for the reduced body condition observed. Understanding the relationship between trawling, benthic impacts, fish foraging and resultant body condition is an important step in designing successful mitigation measures for future management strategies in bottom trawl fisheries. PMID:25621336

  10. Environmental health impacts of feeding crops to farmed fish.

    PubMed

    Fry, Jillian P; Love, David C; MacDonald, Graham K; West, Paul C; Engstrom, Peder M; Nachman, Keeve E; Lawrence, Robert S

    2016-05-01

    Half of the seafood consumed globally now comes from aquaculture, or farmed seafood. Aquaculture therefore plays an increasingly important role in the global food system, the environment, and human health. Traditionally, aquaculture feed has contained high levels of wild fish, which is unsustainable for ocean ecosystems as demand grows. The aquaculture industry is shifting to crop-based feed ingredients, such as soy, to replace wild fish as a feed source and allow for continued industry growth. This shift fundamentally links seafood production to terrestrial agriculture, and multidisciplinary research is needed to understand the ecological and environmental health implications. We provide basic estimates of the agricultural resource use associated with producing the top five crops used in commercial aquaculture feed. Aquaculture's environmental footprint may now include nutrient and pesticide runoff from industrial crop production, and depending on where and how feed crops are produced, could be indirectly linked to associated negative health outcomes. We summarize key environmental health research on health effects associated with exposure to air, water, and soil contaminated by industrial crop production. Our review also finds that changes in the nutritional content of farmed seafood products due to altered feed composition could impact human nutrition. Based on our literature reviews and estimates of resource use, we present a conceptual framework describing the potential links between increasing use of crop-based ingredients in aquaculture and human health. Additional data and geographic sourcing information for crop-based ingredients are needed to fully assess the environmental health implications of this trend. This is especially critical in the context of a food system that is using both aquatic and terrestrial resources at unsustainable rates. PMID:26970884

  11. Environmental health impacts of feeding crops to farmed fish.

    PubMed

    Fry, Jillian P; Love, David C; MacDonald, Graham K; West, Paul C; Engstrom, Peder M; Nachman, Keeve E; Lawrence, Robert S

    2016-05-01

    Half of the seafood consumed globally now comes from aquaculture, or farmed seafood. Aquaculture therefore plays an increasingly important role in the global food system, the environment, and human health. Traditionally, aquaculture feed has contained high levels of wild fish, which is unsustainable for ocean ecosystems as demand grows. The aquaculture industry is shifting to crop-based feed ingredients, such as soy, to replace wild fish as a feed source and allow for continued industry growth. This shift fundamentally links seafood production to terrestrial agriculture, and multidisciplinary research is needed to understand the ecological and environmental health implications. We provide basic estimates of the agricultural resource use associated with producing the top five crops used in commercial aquaculture feed. Aquaculture's environmental footprint may now include nutrient and pesticide runoff from industrial crop production, and depending on where and how feed crops are produced, could be indirectly linked to associated negative health outcomes. We summarize key environmental health research on health effects associated with exposure to air, water, and soil contaminated by industrial crop production. Our review also finds that changes in the nutritional content of farmed seafood products due to altered feed composition could impact human nutrition. Based on our literature reviews and estimates of resource use, we present a conceptual framework describing the potential links between increasing use of crop-based ingredients in aquaculture and human health. Additional data and geographic sourcing information for crop-based ingredients are needed to fully assess the environmental health implications of this trend. This is especially critical in the context of a food system that is using both aquatic and terrestrial resources at unsustainable rates.

  12. Fish oil replacement in current aquaculture feed: is cholesterol a hidden treasure for fish nutrition?

    PubMed

    Norambuena, Fernando; Lewis, Michael; Hamid, Noor Khalidah Abdul; Hermon, Karen; Donald, John A; Turchini, Giovanni M

    2013-01-01

    Teleost fish, as with all vertebrates, are capable of synthesizing cholesterol and as such have no dietary requirement for it. Thus, limited research has addressed the potential effects of dietary cholesterol in fish, even if fish meal and fish oil are increasingly replaced by vegetable alternatives in modern aquafeeds, resulting in progressively reduced dietary cholesterol content. The objective of this study was to determine if dietary cholesterol fortification in a vegetable oil-based diet can manifest any effects on growth and feed utilization performance in the salmonid fish, the rainbow trout. In addition, given a series of studies in mammals have shown that dietary cholesterol can directly affect the fatty acid metabolism, the apparent in vivo fatty acid metabolism of fish fed the experimental diets was assessed. Triplicate groups of juvenile fish were fed one of two identical vegetable oil-based diets, with additional cholesterol fortification (high cholesterol; H-Chol) or without (low cholesterol; L-Chol), for 12 weeks. No effects were observed on growth and feed efficiency, however, in fish fed H-Col no biosynthesis of cholesterol, and a remarkably decreased apparent in vivo fatty acid β-oxidation were recorded, whilst in L-Chol fed fish, cholesterol was abundantly biosynthesised and an increased apparent in vivo fatty acid β-oxidation was observed. Only minor effects were observed on the activity of stearyl-CoA desaturase, but a significant increase was observed for both the transcription rate in liver and the apparent in vivo activity of the fatty acid Δ-6 desaturase and elongase, with increasing dietary cholesterol. This study showed that the possible effects of reduced dietary cholesterol in current aquafeeds can be significant and warrant future investigations.

  13. Fish Oil Replacement in Current Aquaculture Feed: Is Cholesterol a Hidden Treasure for Fish Nutrition?

    PubMed Central

    Norambuena, Fernando; Lewis, Michael; Hamid, Noor Khalidah Abdul; Hermon, Karen; Donald, John A.; Turchini, Giovanni M.

    2013-01-01

    Teleost fish, as with all vertebrates, are capable of synthesizing cholesterol and as such have no dietary requirement for it. Thus, limited research has addressed the potential effects of dietary cholesterol in fish, even if fish meal and fish oil are increasingly replaced by vegetable alternatives in modern aquafeeds, resulting in progressively reduced dietary cholesterol content. The objective of this study was to determine if dietary cholesterol fortification in a vegetable oil-based diet can manifest any effects on growth and feed utilization performance in the salmonid fish, the rainbow trout. In addition, given a series of studies in mammals have shown that dietary cholesterol can directly affect the fatty acid metabolism, the apparent in vivo fatty acid metabolism of fish fed the experimental diets was assessed. Triplicate groups of juvenile fish were fed one of two identical vegetable oil-based diets, with additional cholesterol fortification (high cholesterol; H-Chol) or without (low cholesterol; L-Chol), for 12 weeks. No effects were observed on growth and feed efficiency, however, in fish fed H-Col no biosynthesis of cholesterol, and a remarkably decreased apparent in vivo fatty acid β-oxidation were recorded, whilst in L-Chol fed fish, cholesterol was abundantly biosynthesised and an increased apparent in vivo fatty acid β-oxidation was observed. Only minor effects were observed on the activity of stearyl-CoA desaturase, but a significant increase was observed for both the transcription rate in liver and the apparent in vivo activity of the fatty acid Δ-6 desaturase and elongase, with increasing dietary cholesterol. This study showed that the possible effects of reduced dietary cholesterol in current aquafeeds can be significant and warrant future investigations. PMID:24324720

  14. Fatty Acid Composition of Tropical Fish Depends on Reservoir Trophic Status and Fish Feeding Habit.

    PubMed

    Gomes, Aline D; Tolussi, Carlos E; Boëchat, Iola G; Pompêo, Marcelo L M; Cortez, Maíra P T; Honji, Renato M; Moreira, Renata G

    2016-10-01

    Eutrophication results in a deficiency of n-3 LC-PUFA (long-chain polyunsaturated fatty acids) in aquatic food chains, affecting fish nutrition and physiology. The trophic transfer of FA (fatty acids) to fish species of different feeding habits was investigated in two reservoirs in southeast Brazil-the mesotrophic Ponte Nova Reservoir (PN) and the hypereutrophic Billings Reservoir (Bil). Total FA profile of stomach contents and adipose tissue, triacylglycerols (TAG), and phospholipids (PL) from liver and muscle of the omnivorous Astyanax fasciatus and the carnivorous Hoplias malabaricus were analyzed by gas chromatography. A prevalence of n-6PUFA, as 18:2n-6 (linoleic acid) and 20:4n-6 (arachidonic acid, ARA) was observed in the stomach contents and in the tissues of A. fasciatus from the PN reservoir. In contrast, n-3 LC-PUFA, as 20:5n-3 (eicosapentaenoic acid, EPA) was accumulated in fish tissues from Bil, resulting in higher n3/n6 and EPA/ARA ratios, compared to fish from PN. This differential FA accumulation was also observed for H. malabaricus, but differences were slightly minor, and no changes were observed in the EPA/ARA ratios between fish from both reservoirs. Regardless reservoir, FA profiles of TAG resembled that of their diet, whereas FA profiles of PL were more conservative and mainly comprised by LC-PUFA. We conclude that reservoir trophic status affected the FA composition of food resources available to these fish species, resulting in differential allocation of n-3 and n-6 FA. As expected, FA profile of the investigated fish species also reflected their feeding habit and physiological demands.

  15. Fatty Acid Composition of Tropical Fish Depends on Reservoir Trophic Status and Fish Feeding Habit.

    PubMed

    Gomes, Aline D; Tolussi, Carlos E; Boëchat, Iola G; Pompêo, Marcelo L M; Cortez, Maíra P T; Honji, Renato M; Moreira, Renata G

    2016-10-01

    Eutrophication results in a deficiency of n-3 LC-PUFA (long-chain polyunsaturated fatty acids) in aquatic food chains, affecting fish nutrition and physiology. The trophic transfer of FA (fatty acids) to fish species of different feeding habits was investigated in two reservoirs in southeast Brazil-the mesotrophic Ponte Nova Reservoir (PN) and the hypereutrophic Billings Reservoir (Bil). Total FA profile of stomach contents and adipose tissue, triacylglycerols (TAG), and phospholipids (PL) from liver and muscle of the omnivorous Astyanax fasciatus and the carnivorous Hoplias malabaricus were analyzed by gas chromatography. A prevalence of n-6PUFA, as 18:2n-6 (linoleic acid) and 20:4n-6 (arachidonic acid, ARA) was observed in the stomach contents and in the tissues of A. fasciatus from the PN reservoir. In contrast, n-3 LC-PUFA, as 20:5n-3 (eicosapentaenoic acid, EPA) was accumulated in fish tissues from Bil, resulting in higher n3/n6 and EPA/ARA ratios, compared to fish from PN. This differential FA accumulation was also observed for H. malabaricus, but differences were slightly minor, and no changes were observed in the EPA/ARA ratios between fish from both reservoirs. Regardless reservoir, FA profiles of TAG resembled that of their diet, whereas FA profiles of PL were more conservative and mainly comprised by LC-PUFA. We conclude that reservoir trophic status affected the FA composition of food resources available to these fish species, resulting in differential allocation of n-3 and n-6 FA. As expected, FA profile of the investigated fish species also reflected their feeding habit and physiological demands. PMID:27631676

  16. Evaluation of an alternative to feeding whole frozen fish in belugas (Delphinapterus leucas).

    PubMed

    Mazzaro, Lisa M; Richmond, Julie P; Morgan, Jessica N; Kluever, Michaela E; Dunn, J Lawrence; Romano, Tracy A; Zinn, Steven A; Koutsos, Elizabeth A

    2011-01-01

    Feeding fish to captive piscivores can be challenging owing to cost, availability, variability in nutrient, and caloric composition, as well as handling and storage concerns. This trial evaluated the response of three belugas to being fed Fish Analog, an alternative to frozen fish. Body condition, gut transit time, serum chemistry and metabolic hormone analytes, immune function, and behavioral motivation were the dependent variables. Belugas (n=3) were fed various levels of Fish Analog (0-50%) over a 6-month period, and follow-up studies were conducted to further examine several dependent variables. When provided in gradually increasing amounts, belugas consumed the Fish Analog, with only minor fecal consistency changes and without behavioral responses indicative of gastric discomfort. Axillary girth and blubber thickness were positively correlated, and did not differ significantly with changes in the percentage of Fish Analog fed. Individual animal variation in initial passage time, some serum chemistry analytes, and immune function differences were noted following feeding of Fish Analog. Feeding Fish Analog reduced blood n9 fatty acids compared with captive belugas fed no Fish Analog. Feeding a DHA-enriched Fish Analog increased several n3 fatty acids, including eicosapentaenoic acid, but not DHA, compared with whales fed no Fish Analog or non-DHA-enriched Fish Analog. Fish Analog was shown to be a viable alternative to feeding fish at up to 50% of the dietary caloric density.

  17. Evaluation of an alternative to feeding whole frozen fish in belugas (Delphinapterus leucas).

    PubMed

    Mazzaro, Lisa M; Richmond, Julie P; Morgan, Jessica N; Kluever, Michaela E; Dunn, J Lawrence; Romano, Tracy A; Zinn, Steven A; Koutsos, Elizabeth A

    2011-01-01

    Feeding fish to captive piscivores can be challenging owing to cost, availability, variability in nutrient, and caloric composition, as well as handling and storage concerns. This trial evaluated the response of three belugas to being fed Fish Analog, an alternative to frozen fish. Body condition, gut transit time, serum chemistry and metabolic hormone analytes, immune function, and behavioral motivation were the dependent variables. Belugas (n=3) were fed various levels of Fish Analog (0-50%) over a 6-month period, and follow-up studies were conducted to further examine several dependent variables. When provided in gradually increasing amounts, belugas consumed the Fish Analog, with only minor fecal consistency changes and without behavioral responses indicative of gastric discomfort. Axillary girth and blubber thickness were positively correlated, and did not differ significantly with changes in the percentage of Fish Analog fed. Individual animal variation in initial passage time, some serum chemistry analytes, and immune function differences were noted following feeding of Fish Analog. Feeding Fish Analog reduced blood n9 fatty acids compared with captive belugas fed no Fish Analog. Feeding a DHA-enriched Fish Analog increased several n3 fatty acids, including eicosapentaenoic acid, but not DHA, compared with whales fed no Fish Analog or non-DHA-enriched Fish Analog. Fish Analog was shown to be a viable alternative to feeding fish at up to 50% of the dietary caloric density. PMID:21319209

  18. Suction patterns in preterm infants.

    PubMed

    Martell, M; Martínez, G; González, M; Díaz Rosselló, J L

    1993-01-01

    The suction pattern for breast and bottle feeding in two groups of preterm infants is described. The time elapsed between birth and the moment of suction was longer in preterm neonates born at lower gestational ages for both groups studied, breast and bottle fed (figure 1). The evolution of suckling in breastfeeding was analyzed in a composite study (longitudinal and transverse) in a group of 16 neonates starting from 32 weeks of gestation. The velocity of milk extraction during suckling varied with gestational age. It was uniform at lower gestational ages, then it became faster in the first minutes and at the 36th week, it was very similar to that of mature neonates (figure 2 and table I). The evaluation of bottle feeding was performed in a transverse study in 46 preterm neonates which had been exclusively bottle fed during 1 or 2 weeks. All of them had previously been fed using an orogastric tube. Nourishing time was shorter than in breastfeeding; the average duration was 3.7 minutes (table II). The greatest volume was ingested in the first minute, 40% (range between 44 and 25%) (figure 3). The frequency of suction did not change the duration of feeding, but it was found that the efficiency of suction (number of suctions to ingest 1 cc) was significantly lower in the first minute (Anova, p < 0.05) (figure 4).

  19. Potential uses of gut weed Enteromorpha spp. as a feed for herbivorous fish.

    PubMed

    Anh, Nguyen Thi Ngoc; Hien, Tran Thi Thanh; Hai, Tran Ngoc

    2013-01-01

    Three separate experiments were performed to assess the potential use of gut weeds Enteromorpha spp. as a food source for herbivorous fish. The fresh or dried gut weeds were used as a direct feed to replace commercial feed in an alternative approach for feeding spotted seat (Scatophagus argus), red tilapia (Oreochromis sp.), and giant gourami (Osphronemus goramy) juveniles for 60 days, 45 days, and 56 days, respectively. Four feeding regimes were applied to triplicate tanks and fish was fed daily either commercial feed or gut weed: (1) single commercial feed everyday as a control treatment, (2) single gut weed daily and 2 alternative feeding regimes where (3) 1 day commercial feed and 1 consecutive day gut weed or and (4) 2 consecutive days gut weed. The results indicated that survival of experimental fish was not affected by the feeding treatments. Growth performance of the S. argus fed single gut weed was not significantly different from the control group (P>0.05). Growth rates of Oreochromis sp. and O. goramy in the alternative feeding treatments were comparable to the control treatment. Application of the combined feeding regimes, feed conversion ratio could be reduced from 26.1 to 57.8%. These results indicated that fresh and dried gut weed can be used as a feed to substitute commercial feed for herbivorous fish. Moreover, using gut weeds as a feed could improve water quality in the rearing tanks.

  20. Potential uses of gut weed Enteromorpha spp. as a feed for herbivorous fish.

    PubMed

    Anh, Nguyen Thi Ngoc; Hien, Tran Thi Thanh; Hai, Tran Ngoc

    2013-01-01

    Three separate experiments were performed to assess the potential use of gut weeds Enteromorpha spp. as a food source for herbivorous fish. The fresh or dried gut weeds were used as a direct feed to replace commercial feed in an alternative approach for feeding spotted seat (Scatophagus argus), red tilapia (Oreochromis sp.), and giant gourami (Osphronemus goramy) juveniles for 60 days, 45 days, and 56 days, respectively. Four feeding regimes were applied to triplicate tanks and fish was fed daily either commercial feed or gut weed: (1) single commercial feed everyday as a control treatment, (2) single gut weed daily and 2 alternative feeding regimes where (3) 1 day commercial feed and 1 consecutive day gut weed or and (4) 2 consecutive days gut weed. The results indicated that survival of experimental fish was not affected by the feeding treatments. Growth performance of the S. argus fed single gut weed was not significantly different from the control group (P>0.05). Growth rates of Oreochromis sp. and O. goramy in the alternative feeding treatments were comparable to the control treatment. Application of the combined feeding regimes, feed conversion ratio could be reduced from 26.1 to 57.8%. These results indicated that fresh and dried gut weed can be used as a feed to substitute commercial feed for herbivorous fish. Moreover, using gut weeds as a feed could improve water quality in the rearing tanks. PMID:25141699

  1. Associations among coral reef macroalgae influence feeding by herbivorous fishes

    NASA Astrophysics Data System (ADS)

    Loffler, Z.; Bellwood, D. R.; Hoey, A. S.

    2015-03-01

    Benthic macroalgae often occur in close association with other macroalgae, yet the implications of such associations on coral reefs are unclear. We selected three pairs of commonly associated macroalgae on inshore reefs of the Great Barrier Reef and exposed them, either independently or paired, to herbivore assemblages. Pairing the palatable alga Acanthophora with the calcified and chemically defended Galaxaura resulted in a 69 % reduction in the consumption of Acanthophora, but had no effect on the consumption of Galaxaura. The reduced consumption of Acanthophora was related to 53-85 % reductions in the feeding rates of two herbivorous fish species, Kyphosus vaigiensis and Siganus doliatus. Neither Acanthophora nor Sargassum were afforded protection when paired with the brown macroalga Turbinaria. Although limited to one of the three species pairings, such associations between algae may allow the ecological persistence of palatable species in the face of intense herbivory, enhancing macroalgal diversity on coral reefs.

  2. Is post-feeding thermotaxis advantageous in elasmobranch fishes?

    PubMed

    Di Santo, V; Bennett, W A

    2011-01-01

    The effects of post-feeding thermotaxis on ileum evacuation and absorption rates were examined in the laboratory using two elasmobranch species, the Atlantic stingray Dasyatis sabina, which inhabits thermally variable environments, and the whitespotted bamboo shark Chiloscyllium plagiosum, a stenothermic fish living on Indo-Pacific reefs. Experiments at temperatures similar to those experienced in nature revealed temperature change had no significant effect on C. plagiosum absorption or evacuation rates, suggesting stenothermic sharks cannot exploit temperature differences as a means to improve digestion efficiency. On the other hand, D. sabina showed significantly lower evacuation and absorption rates at lower temperatures. The relative decrease was greater for evacuation (Q₁₀ = 3·08) than absorption rates (Q₁₀ = 2·20), resulting in a significant increase in total absorption, suggesting D. sabina can benefit from using shuttling behaviour to exploit thermal variability in their environment to maximize energetic uptake. PMID:21235555

  3. Proteome analysis of pyloric ceca: a methodology for fish feed development?

    PubMed

    Wulff, Tune; Petersen, Jørgen; Nørrelykke, Mette R; Jessen, Flemming; Nielsen, Henrik H

    2012-08-29

    Changing the protein source of fish feed from fish meal to alternative sources of protein will affect traits such as fish growth, quality, and feed utilization. The present investigation was initiated to introduce a two-dimensional gel electrophoresis based proteomic workflow as a tool to investigate feed effects on fish by analyzing protein changes in the fish gut. The workflow was used to study the effect of substituting fish meal in fish feed by alternative sources of protein. Rainbow trout divided into five groups were fed for 72 days with feeds varying in protein composition. By two-dimensional gel electrophoresis proteins extracted from the pyloric ceca were separated, making it possible to measure the abundance of more than 440 protein spots. The expression of 41 protein spots was found to change due to differences in feed composition. By mass spectrometry 31 of these proteins were identified, including proteins involved in digestion (trypsinogen, carboxylic ester hydrolase, and aminopeptidase). The many expression changes indicated that the trout, when adapting to differences in feed formulation, alter the protein composition of the gut.

  4. Continuous recording of uneaten food pellets and demand-feeding activity: a new approach to studying feeding rhythms in fish.

    PubMed

    Madrid, J A; Azzaydi, M; Zamora, S; Sánchez-Vázquez, F J

    1997-10-01

    The existence of feeding rhythms implies that fish would feed better during their preferred feeding phase but reject food at any other time. In the present paper, we tested the performance of a new device for continuously collecting and detecting uneaten food pellets. The device is basically made of two parts: a pellet collector placed just under the feeder and a decanter with a sensor attached to the bottom. When a food pellet was not eaten, it was rapidly collected and transferred to the decanter, where it was detected while dropping by an infrared sensor coupled to a microcomputer. To validate this system, five groups of fifteen sea bass, Dicentrachus labrax L., were maintained under natural conditions and subjected to a daily feeding cycle (feeding rate = 2.5% of body weight) consisting of three meals of one hour duration each (0800-0900 h, 1600-1700 h and 2400-0100 h). Uneaten pellets together with demand-feeding activity were simultaneously recorded. In addition to these test tanks, "natural" demand-feeding rhythms were also investigated in five groups of sea bass maintained under an ad lib self-feeding regime. In the test tanks, when submitted to the three meal feeding cycle, sea bass showed clear time preferences for feeding, since they fed mostly during the morning and afternoon, rejecting food at night. Consequently, the profile of uneaten pellets peaked at night butt remained very low during daytime. This diurnal preference for feeding is consistent with the almost strict diurnal feeding rhythm found in the sea bass groups under ad lib self-feeding. These results revealed the usefulness of this device in estimating food utilization and its potential application in nutritional and chronobiological studies in fish.

  5. Organochlorine pesticides residues in feed and muscle of farmed Nile tilapia from Brazilian fish farms.

    PubMed

    Botaro, Daniele; Torres, João Paulo Machado; Malm, Olaf; Rebelo, Mauro Freitas; Henkelmann, Bernhard; Schramm, Karl-Werner

    2011-09-01

    Organochlorine pesticide (OCP) concentrations were determined in fish muscle and feed collected from four different fish farms in Brazil. Nile tilapia from two growth stages, juveniles and adults, collected at two intensive tanks farms (IT1 and IT2) and two net cage farms (NC1 and NC2), were analyzed by High Resolution Gas Chromatography/High Resolution Mass Spectrometry. Pesticides were detected in almost all samples, but no samples exceeded international maximum limits for safe fish consumption. ΣDDT was the predominant pesticide in fish muscle, found in all fish samples, and endosulfan was the most predominant pesticide in feed, found in all feed samples. No significant correlation (p>0.05) was observed between the different growth stages and OCP concentrations, although slightly higher OCP concentrations were observed in adults. Among the rearing systems, NC farmed fish presented higher lipid levels and, consequently, higher OCP concentrations than fish from IT farms. Some OCPs (ΣHCH, aldrin, dieldrin and endrin) presented strong positive correlations (p<0.05) between feed and fish muscle concentrations, while others (ΣDDT, mirex, chlordane, ΣHCB and endosulfan) presented no correlation. However, the low levels of the sum of contaminants found in most of the feed samples may explain the low contaminant levels in fish tissue.

  6. Is nasogastric suction necessary in acute pancreatitis?

    PubMed Central

    Naeije, R; Salingret, E; Clumeck, N; De Troyer, A; Devis, G

    1978-01-01

    Fifty-eight patients with mild to moderately severe acute pancreatitis were randomly allocated to treatment with or without nasogastric suction (27 and 31 patients respectively). Intravenous fluids and pethidine hydrochloride were also given. The two groups were comparable clinically at the start of the study. There were no differences between the two groups in the mean duration of the following features: abdominal pain or tenderness; absence of bowel movements; raised serum amylase concentration; time to resumption of oral feeding; and days in hospital. Prolonged hyperamylasaemia (serum amylase greater than 0.33 mU/l) occurred in one patient in the suction group and in three patients in the non-suction group. A mild recurrence of abdominal pain after resumption of oral feeding occurred in three patients in the suction group and in two patients in the non-suction group. Two patients in the suction group developed overt consumption coagulopathy and two others pulmonary complications. No patient in the non-suction group had complications. The findings suggest that most patients with mild to moderately severe acute pancreatitis do not benefit from nasogastric suction. The procedure should be elective rather than mandatory in treating this condition. PMID:698650

  7. Effects of various feed supplements containing fish protein hydrolysate or fish processing by-products on the innate immune functions of juvenile coho salmon (oncorhynchus kisutch)

    USGS Publications Warehouse

    Murray, A.L.; Pascho, R.J.; Alcorn, S.W.; Fairgrieve, W.T.; Shearer, K.D.; Roley, D.

    2003-01-01

    Immunomodulators administered to fish in the diet have been shown in some cases to enhance innate immune defense mechanisms. Recent studies have suggested that polypeptide fractions found in fish protein hydrolysates may stimulate factors in fish important for disease resistance. For the current study, groups of coho salmon were reared on practical feeds that contained either fish meal (Control diet), fish meal supplemented with cooked fish by-products, or fish meal supplemented with hydrolyzed fish protein alone, or with hydrolyzed fish protein and processed fish bones. For each diet group, three replicate tanks of fish were fed the experimental diets for 6 weeks. Morphometric measurements, and serologic and cellular assays were used to evaluate the general health and immunocompetence of fish in the various feed groups. Whereas the experimental diets had no effect on the morphometric and cellular measurements, fish fed cooked by-products had increased leucocrit levels and lower hematocrit levels than fish from the other feed groups. Innate cellular responses were increased in all feed groups after feeding the four experimental diets compared with pre-feed results. Subgroups of fish from each diet group were also challenged with Vibrio anguillarum (ca. 7.71 ?? 105 bacteria ml-1) at 15??C by immersion. No differences were found in survival among the various feed groups.

  8. Feeding response of sport fish after electrical immobilization, chemical sedation, or both

    USGS Publications Warehouse

    Meinertz, Jeffery R.; Fredricks, Kim T.; Ambrose, Ryan D.; Jackan, Leanna M.; Wise, Jeremy K.

    2012-01-01

    Fishery managers frequently capture wild fish for a variety of fishery management activities. Though some activities can be accomplished without immobilizing the fish, others are accomplished more readily, humanely, and safely (for both the handler and the fish) when fish are immobilized by physical (e.g., electrical immobilization) or chemical sedation. A concern regarding the use of chemical sedatives is that chemical residues may remain in the fillet tissue after the fish recovers from sedation. If those residues are harmful to humans, there is some risk that a postsedated fish released to public waters may be caught and consumed by an angler. To characterize this risk, a series of four trials were conducted. Three trials assessed feeding activity after hatchery-reared fish were electrically immobilized, chemically sedated, or both, and one trial assessed the likelihood of an angler catching a wild fish that had been electrically immobilized and chemically sedated. Results from the first trial indicated that the feeding activity of laboratory habituated fish was variable among and within species after electrical immobilization, chemical sedation, or both. Results from the second trial indicated that the resumption of feeding activity was rapid after being mildly sedated for 45 min. Results from the third trial indicated that the feeding activity of outdoor, hatchery-reared fish was relatively aggressive after fish had been chemically sedated. Results from the fourth trial indicated that the probability of capturing wild fish in a more natural environment by angling after fish had been electrically immobilized and chemically sedated is not likely, i.e., in a group of five fish caught, 3 out of 100 times one would be a fish that had been sedated.

  9. Occurrence of Deoxynivalenol and Zearalenone in Commercial Fish Feed: An Initial Study

    PubMed Central

    Pietsch, Constanze; Kersten, Susanne; Burkhardt-Holm, Patricia; Valenta, Hana; Dänicke, Sven

    2013-01-01

    The control of mycotoxins is a global challenge not only in human consumption but also in nutrition of farm animals including aquatic species. Fusarium toxins, such as deoxynivalenol (DON) and zearalenone (ZEN), are common contaminants of animal feed but no study reported the occurrence of both mycotoxins in fish feed so far. Here, we report for the first time the occurrence of DON and ZEN in samples of commercial fish feed designed for nutrition of cyprinids collected from central Europe. A maximal DON concentration of 825 μg kg−1 feed was found in one feed whereas average values of 289 μg kg−1 feed were noted. ZEN was the more prevalent mycotoxin but the concentrations were lower showing an average level of 67.9 μg kg−1 feed. PMID:23325300

  10. Chemical contaminants in fish feeds used in federal salmonid hatcheries in the USA

    USGS Publications Warehouse

    Maule, A.G.; Gannam, A.L.; Davis, J.W.

    2007-01-01

    Recent studies have demonstrated that fish feeds contain significant concentrations of contaminants, many of which can bioaccumulate and bioconcentrate in fish. Organochlorine (OC) contaminants are present in the fish oils and fish meals used in feed manufacture, and some researchers speculate that all fish feeds contain measurable levels of some contaminants. To determine the concentration of contaminants in feeds used in US Fish and Wildlife Service's National Fish Hatcheries, we systematically collected samples of feed from 11 cold-water fish hatcheries. All samples (collected from October 2001 to October 2003) contained at least one polychlorinated dibenzo-p-dioxin (PCDD), polychlorinated dibenzofuran (PCDF), polychlorinated biphenyl (PCB) congener, or dichlorodiphenyltrichloroethane (DDT) metabolite. Of the 55 samples in which they were analyzed 39 contained PCDDs, 24 contained PCDFs and 24 contained DDT or its metabolites. There were 10- to 150-fold differences in concentrations of total PCBs, PCDDs, PCDFs and DDT. Although PCBs were the most commonly detected contaminant in our study, concentrations (range: 0.07-10.46 ng g-1 wet weight) were low compared to those reported previously. In general, we also found lower levels of OCs than reported previously in fish feed. Perhaps most notable was the near absence of OC pesticides - except for DDT or its metabolites, and two samples containing hexachlorocyclohexane (HCH). While contaminant concentrations were generally low, the ecological impacts can not be determined without a measure of the bioaccumulation of these compounds in the fish and the fate of these compounds after the fish are released. ?? 2006 Elsevier Ltd. All rights reserved.

  11. Wastewater-grown duckweed may be safely used as fish feed.

    PubMed

    Islam, M S; Kabir, M S; Khan, S I; Ekramullah, M; Nair, G B; Sack, R B; Sack, D A

    2004-01-01

    Duckweed has been used for the treatment of wastewater and as fish feed. A comparative study was carried out to determine (i) the efficacy of duckweed in treating hospital-based wastewater and (ii) the level of the microbial contamination of fish fed on wastewater-grown duckweed. There were two groups of ponds where fish farming was done. In one group of ponds (control ponds), duckweed that was grown using artificial fertilizer was used as fish feed; in another group (study ponds), wastewater-grown duckweed was used as fish feed. The faecal contamination of water, duckweed, and fish from study and control ponds were monitored by faecal coliform estimation. The presence of enteric pathogens among handlers, water, duckweed, and fish samples was also examined. It was observed that the faecal coliform counts of raw wastewater were 4.7 Log10 CFU/mL, which was reduced to <1 Log10 CFU/mL after treating with duckweed. There was no significant difference (P > 0.05) in faecal coliform counts in water collected from duckweed ponds and fish ponds of study and control areas. The wastewater-grown duckweed did not pose any health hazard to the handlers. These results demonstrated that the wastewater-treated duckweed may be safely used as fish feed.

  12. Natural occurrence of emerging Fusarium mycotoxins in feed and fish from aquaculture.

    PubMed

    Tolosa, Josefa; Font, Guillermina; Mañes, Jordi; Ferrer, Emilia

    2014-12-24

    A new analytical method for the simultaneous determination of enniatins (ENs) and beauvericin (BEA) in fish feed and fish tissues by liquid chromatography coupled to mass spectrometry with linear ion trap (LC-MS/MS-LIT) was developed. Results showed that the developed method is precise and sensitive. The presence of emerging Fusarium mycotoxins, ENs and BEA, was determined in samples of aquaculture fish and feed for farmed fish, showing that all feed samples analyzed were contaminated with mycotoxins, with 100% coexistence. In aquacultured fish samples, the highest incidence was found in edible muscle and liver. As for the exposure assessment calculated, it was found that average consumer intake was lower than tolerable daily intake (TDI) values for other Fusarium mycotoxins. PMID:25432004

  13. Natural occurrence of emerging Fusarium mycotoxins in feed and fish from aquaculture.

    PubMed

    Tolosa, Josefa; Font, Guillermina; Mañes, Jordi; Ferrer, Emilia

    2014-12-24

    A new analytical method for the simultaneous determination of enniatins (ENs) and beauvericin (BEA) in fish feed and fish tissues by liquid chromatography coupled to mass spectrometry with linear ion trap (LC-MS/MS-LIT) was developed. Results showed that the developed method is precise and sensitive. The presence of emerging Fusarium mycotoxins, ENs and BEA, was determined in samples of aquaculture fish and feed for farmed fish, showing that all feed samples analyzed were contaminated with mycotoxins, with 100% coexistence. In aquacultured fish samples, the highest incidence was found in edible muscle and liver. As for the exposure assessment calculated, it was found that average consumer intake was lower than tolerable daily intake (TDI) values for other Fusarium mycotoxins.

  14. Food wastes as fish feeds for polyculture of low-trophic-level fish: bioaccumulation and health risk assessments of heavy metals in the cultured fish.

    PubMed

    Cheng, Zhang; Lam, Cheung-Lung; Mo, Wing-Yin; Nie, Xiang-Ping; Choi, Wai-Ming; Man, Yu-Bon; Wong, Ming-Hung

    2016-04-01

    The major purpose of this study was to use different types of food wastes which serve as the major sources of protein to replace the fish meal used in fish feeds to produce quality fish. Two types of food waste-based feed pellets FW A (with cereals) and FW B (with cereals and meat products) and the commercial feed Jinfeng® were used to culture fingerlings of three low-trophic-level fish species: bighead carp, grass carp, and mud carp (in the ratio of 1:3:1) for 1 year period in the Sha Tau Kok Organic Farm in Hong Kong. Heavy metal concentrations in all of the fish species fed with food waste pellets and commercial pellets in Sha Tau Kok fish ponds were all below the local and international maximum permissible levels in food. Health risk assessments indicated that human consumption of the fish fed with food waste feed pellets was safe for the Hong Kong residents. The present results revealed that recycling of food waste for cultivating low-trophic-level fish (mainly herbivores and detritus feeders) is feasible, and at the same time will ease the disposal pressure of food waste, a common problem of densely populated cities like Hong Kong. PMID:27002811

  15. Levels of synthetic antioxidants (ethoxyquin, butylated hydroxytoluene and butylated hydroxyanisole) in fish feed and commercially farmed fish.

    PubMed

    Lundebye, A-K; Hove, H; Måge, A; Bohne, V J B; Hamre, K

    2010-12-01

    Several synthetic antioxidants are authorized for use as feed additives in the European Union. Ethoxyquin (EQ) and butylated hydroxytoluene (BHT) are generally added to fish meal and fish oil, respectively, to limit lipid oxidation. The study was conducted to examine the concentrations of EQ, BHT and butylated hydroxyanisole (BHA) in several commercially important species of farmed fish, namely Atlantic salmon, halibut and cod and rainbow trout, as well as concentrations in fish feed. The highest levels of BHT, EQ and BHA were found in farmed Atlantic salmon fillets, and were 7.60, 0.17 and 0.07 mg kg(-1), respectively. The lowest concentrations of the synthetic antioxidants found were in cod. The concentration of the oxidation product ethoxyquin dimer (EQDM) was more than ten-fold higher than the concentration of parent EQ in Atlantic salmon halibut and rainbow trout, whereas this dimer was not detected in cod fillets. The theoretical consumer exposure to the synthetic antioxidants EQ, BHA and BHT from the consumption of farmed fish was calculated. The contribution of EQ from a single portion (300 g) of skinned fillets of the different species of farmed fish would contribute at most 15% of the acceptable daily intake (ADI) for a 60 kg adult. The consumption of farmed fish would not contribute measurably to the intake of BHA; however, a 300 g portion of farmed Atlantic salmon would contribute up to 75% of the ADI for BHT.

  16. Nutritional enrichment of larval fish feed with thraustochytrid producing polyunsaturated fatty acids and xanthophylls.

    PubMed

    Yamasaki, Takashi; Aki, Tsunehiro; Mori, Yuhsuke; Yamamoto, Takeki; Shinozaki, Masami; Kawamoto, Seiji; Ono, Kazuhisa

    2007-09-01

    In marine aquaculture, rotifers and Artemia nauplii employed as larval fish feed are often nutritionally enriched with forage such as yeast and algal cells supplemented with polyunsaturated fatty acids and xanthophylls, which are required for normal growth and a high survival ratio of fish larvae. To reduce the enrichment steps, we propose here the use of a marine thraustochytrid strain, Schizochytrium sp. KH105, producing docosahexaenoic acid, docosapentaenoic acid, canthaxanthin, and astaxanthin. The KH105 cells prepared by cultivation under optimized conditions were successfully incorporated by rotifers and Artemia nauplii. The contents of docosahexaenoic acid surpassed the levels required in feed for fish larvae, and the enriched Artemia showed an increased body length. The results demonstrate that we have developed an improved method of increasing the dietary value of larval fish feed. PMID:17964484

  17. Hiding and feeding in floating seaweed: Floating seaweed clumps as possible refuges or feeding grounds for fishes

    NASA Astrophysics Data System (ADS)

    Vandendriessche, Sofie; Messiaen, Marlies; O'Flynn, Sarah; Vincx, Magda; Degraer, Steven

    2007-02-01

    Floating seaweed is considered to be an important habitat for juvenile fishes due to the provision of food, shelter, a visual orientation point and passive transport. The importance of the presence of the highly dynamical seaweed clumps from the North Sea to juvenile neustonic fishes was investigated by analysing both neuston samples (without seaweed) and seaweed samples concerning fish community structure, and length-frequency distributions and feeding habits of five associated fish species. While the neustonic fish community was mainly seasonally structured, the seaweed-associated fish community was more complex: the response of the associated fish species to environmental variables was species specific and probably influenced by species interactions, resulting in a large multivariate distance between the samples dominated by Chelon labrosus and the samples dominated by Cyclopterus lumpus, Trachurus trachurus and Ciliata mustela. The results of the stomach analysis confirmed that C. lumpus is a weedpatch specialist that has a close spatial affinity with the seaweed and feeds intensively on the seaweed-associated invertebrate fauna. Similarly, C. mustela juveniles also fed on the seaweed fauna, but in a more opportunistic way. The shape of the size-frequency distribution suggested enhanced growth when associated with floating seaweed. Chelon labrosus and T. trachurus juveniles were generally large in seaweed samples, but large individuals were also encountered in the neuston. The proportion of associated invertebrate fauna in their diet was of minor importance, compared to the proportions in C. lumpus. Individuals of Syngnathus rostellatus mainly fed on planktonic invertebrates but had a discontinuous size-frequency distribution, suggesting that some of the syngnathids were carried with the seaweed upon detachment and stayed associated. Floating seaweeds can therefore be regarded as ephemeral habitats shared between several fish species (mainly juveniles) that use

  18. Evaluation of the in Vitro Anti-Atherogenic Properties of Lipid Fractions of Olive Pomace, Olive Pomace Enriched Fish Feed and Gilthead Sea Bream (Sparus aurata) Fed with Olive Pomace Enriched Fish Feed

    PubMed Central

    Nasopoulou, Constantina; Gogaki, Vassiliki; Stamatakis, Giorgos; Papaharisis, Leonidas; Demopoulos, Constantinos A.; Zabetakis, Ioannis

    2013-01-01

    Given the pivotal role of Platelet-Activating-Factor (PAF) in atherosclerosis and the cardio-protective role of PAF-inhibitors derived from olive pomace, the inclusion of olive pomace in fish feed has been studied for gilthead sea bream (Sparus aurata). The aim of the current research was to elucidate the anti-atherogenic properties of specific HPLC lipid fractions obtained from olive pomace, olive pomace enriched fish feed and fish fed with the olive pomace enriched fish feed, by evaluating their in vitro biological activity against washed rabbit platelets. This in vitro study underlines that olive pomace inclusion in fish feed improves the nutritional value of both fish feed and fish possibly by enriching the marine lipid profile of gilthead sea bream (Sparus aurata) with specific bioactive lipid compounds of plant origin. PMID:24084786

  19. Aquatic macrophytes as feeding site for small fishes in the Rosana Reservoir, Paranapanema River, southeastern Brazil.

    PubMed

    Casatti, L; Mendes, H F; Ferreira, K M

    2003-05-01

    In the present investigation we studied the feeding habits of the fishes associated with aquatic macrophytes in the Rosana Reservoir, southeastern Brazil. Twenty fish species were collected during four field trips, regularly distributed across the dry and wet seasons. Focal snorkeling observations of the fishes were made over a total of six hours. Nine species were present in abundances of more than 1% and, therefore, had their feeding habits analyzed. Hemigrammus marginatus, Roeboides paranensis, Hyphessobrycon eques, Astyanax altiparanae, Serrasalmus spilopleura, and Bryconamericus stramineus were predominantly invertivores, with predominance of aquatic insects (Diptera, Ephemeroptera, and Trichoptera immatures) among their food items. The predominantly algivores were Apareiodon affinis, Serrapinnus notomelas, and Satanoperca pappaterra, with high frequency of filamentous blue-green algae, diatoms, clorophyts, and periderm. The different microhabitat exploitation plus diet composition suggests partitioning of resources and absence of food competition among the most representative fish species in the studied community, indicating the importance of the naturalistic approach to fish ecology studies.

  20. Within-colony feeding selectivity by a corallivorous reef fish: foraging to maximize reward?

    PubMed Central

    Brooker, Rohan M; Jones, Geoffrey P; Munday, Philip L

    2013-01-01

    Foraging theory predicts that individuals should choose a prey that maximizes energy rewards relative to the energy expended to access, capture, and consume the prey. However, the relative roles of differences in the nutritive value of foods and costs associated with differences in prey accessibility are not always clear. Coral-feeding fishes are known to be highly selective feeders on particular coral genera or species and even different parts of individual coral colonies. The absence of strong correlations between the nutritional value of corals and prey preferences suggests other factors such as polyp accessibility may be important. Here, we investigated within-colony feeding selectivity by the corallivorous filefish, Oxymonacanthus longirostris, and if prey accessibility determines foraging patterns. After confirming that this fish primarily feeds on coral polyps, we examined whether fish show a preference for different parts of a common branching coral, Acropora nobilis, both in the field and in the laboratory experiments with simulated corals. We then experimentally tested whether nonuniform patterns of feeding on preferred coral species reflect structural differences between polyps. We found that O. longirostris exhibits nonuniform patterns of foraging in the field, selectively feeding midway along branches. On simulated corals, fish replicated this pattern when food accessibility was equal along the branch. However, when food access varied, fish consistently modified their foraging behavior, preferring to feed where food was most accessible. When foraging patterns were compared with coral morphology, fish preferred larger polyps and less skeletal protection. Our results highlight that patterns of interspecific and intraspecific selectivity can reflect coral morphology, with fish preferring corals or parts of coral colonies with structural characteristics that increase prey accessibility. PMID:24324862

  1. Algae in Fish Feed: Performances and Fatty Acid Metabolism in Juvenile Atlantic Salmon

    PubMed Central

    Norambuena, Fernando; Hermon, Karen; Skrzypczyk, Vanessa; Emery, James A.; Sharon, Yoni; Beard, Alastair; Turchini, Giovanni M.

    2015-01-01

    Algae are at the base of the aquatic food chain, producing the food resources that fish are adapted to consume. Previous studies have proven that the inclusion of small amounts (<10% of the diet) of algae in fish feed (aquafeed) resulted in positive effects in growth performance and feed utilisation efficiency. Marine algae have also been shown to possess functional activities, helping in the mediation of lipid metabolism, and therefore are increasingly studied in human and animal nutrition. The aim of this study was to assess the potentials of two commercially available algae derived products (dry algae meal), Verdemin (derived from Ulva ohnoi) and Rosamin (derived from diatom Entomoneis spp.) for their possible inclusion into diet of Atlantic Salmon (Salmo salar). Fish performances, feed efficiency, lipid metabolism and final product quality were assessed to investigated the potential of the two algae products (in isolation at two inclusion levels, 2.5% and 5%, or in combination), in experimental diets specifically formulated with low fish meal and fish oil content. The results indicate that inclusion of algae product Verdemin and Rosamin at level of 2.5 and 5.0% did not cause any major positive, nor negative, effect in Atlantic Salmon growth and feed efficiency. An increase in the omega-3 long-chain polyunsaturated fatty acid (n-3 LC-PUFA) content in whole body of fish fed 5% Rosamin was observed. PMID:25875839

  2. Algae in fish feed: performances and fatty acid metabolism in juvenile Atlantic Salmon.

    PubMed

    Norambuena, Fernando; Hermon, Karen; Skrzypczyk, Vanessa; Emery, James A; Sharon, Yoni; Beard, Alastair; Turchini, Giovanni M

    2015-01-01

    Algae are at the base of the aquatic food chain, producing the food resources that fish are adapted to consume. Previous studies have proven that the inclusion of small amounts (<10% of the diet) of algae in fish feed (aquafeed) resulted in positive effects in growth performance and feed utilisation efficiency. Marine algae have also been shown to possess functional activities, helping in the mediation of lipid metabolism, and therefore are increasingly studied in human and animal nutrition. The aim of this study was to assess the potentials of two commercially available algae derived products (dry algae meal), Verdemin (derived from Ulva ohnoi) and Rosamin (derived from diatom Entomoneis spp.) for their possible inclusion into diet of Atlantic Salmon (Salmo salar). Fish performances, feed efficiency, lipid metabolism and final product quality were assessed to investigated the potential of the two algae products (in isolation at two inclusion levels, 2.5% and 5%, or in combination), in experimental diets specifically formulated with low fish meal and fish oil content. The results indicate that inclusion of algae product Verdemin and Rosamin at level of 2.5 and 5.0% did not cause any major positive, nor negative, effect in Atlantic Salmon growth and feed efficiency. An increase in the omega-3 long-chain polyunsaturated fatty acid (n-3 LC-PUFA) content in whole body of fish fed 5% Rosamin was observed.

  3. Algae in fish feed: performances and fatty acid metabolism in juvenile Atlantic Salmon.

    PubMed

    Norambuena, Fernando; Hermon, Karen; Skrzypczyk, Vanessa; Emery, James A; Sharon, Yoni; Beard, Alastair; Turchini, Giovanni M

    2015-01-01

    Algae are at the base of the aquatic food chain, producing the food resources that fish are adapted to consume. Previous studies have proven that the inclusion of small amounts (<10% of the diet) of algae in fish feed (aquafeed) resulted in positive effects in growth performance and feed utilisation efficiency. Marine algae have also been shown to possess functional activities, helping in the mediation of lipid metabolism, and therefore are increasingly studied in human and animal nutrition. The aim of this study was to assess the potentials of two commercially available algae derived products (dry algae meal), Verdemin (derived from Ulva ohnoi) and Rosamin (derived from diatom Entomoneis spp.) for their possible inclusion into diet of Atlantic Salmon (Salmo salar). Fish performances, feed efficiency, lipid metabolism and final product quality were assessed to investigated the potential of the two algae products (in isolation at two inclusion levels, 2.5% and 5%, or in combination), in experimental diets specifically formulated with low fish meal and fish oil content. The results indicate that inclusion of algae product Verdemin and Rosamin at level of 2.5 and 5.0% did not cause any major positive, nor negative, effect in Atlantic Salmon growth and feed efficiency. An increase in the omega-3 long-chain polyunsaturated fatty acid (n-3 LC-PUFA) content in whole body of fish fed 5% Rosamin was observed. PMID:25875839

  4. Feeding behaviour of Black Sea bottom fishes: Did it change over time?

    NASA Astrophysics Data System (ADS)

    Bănaru, Daniela; Harmelin-Vivien, Mireille

    2009-11-01

    This study was designed to improve knowledge in feeding behaviour of the round goby ( Apollonia melanostomus (Pallas, 1814)), the red mullet ( Mullus barbatus ponticus Essipov, 1927), the whiting ( Merlangius merlangus (Linnaeus, 1758)), the flounder ( Platichthys flesus (Linnaeus, 1758)), the sole ( Solea solea (Linnaeus, 1758)), the turbot ( Psetta maeotica (Pallas, 1814)) and the starry sturgeon ( Acipenser stellatus Pallas, 1771) from the north-western Black Sea. Gut content coupled with stable isotope analysis allowed describing food web variations according to species, in two seasons and at two areas located seawards the Danube River. Present results showed that most fishes have likely changed their feeding behaviour compared to past studies from the same area. Trophic niches were reduced and dietary overlap was common, as different fish species consumed the same dominant prey types. Fishes probably adapted their feeding behaviour to the increasingly low biodiversity of the Black Sea communities.

  5. Are kissing gourami specialized for substrate-feeding? Prey capture kinematics of Helostoma temminckii and other anabantoid fishes.

    PubMed

    Ferry, Lara A; Konow, Nicolai; Gibb, Alice C

    2012-11-01

    Helostoma temminckii are known for a "kissing" behavior, which is often used in intraspecific interactions, and an unusual cranial morphology that is characterized by an intramandibular joint (IMJ). The IMJ is located within the lower jaw and aids in generating the eponymous kissing movement. In other teleost linages the IMJ is associated with the adoption of a substrate-grazing foraging habit. However, because of anatomical modifications of the gill-rakers, Helostoma has been considered a midwater filter-feeding species. We offered midwater, benthic, and attached food to Helostoma, Betta, and two "true" osphronemid gouramis, to ask: (1) how do food capture kinematics differ in different foraging contexts; and (2) are Helostoma feeding kinematics distinct when compared with closely related anabantoids that lack an IMJ? For all anabantoid species except Helostoma, benthic prey were captured using a greater contribution of effective suction relative to midwater prey, though Helostoma was rarely willing to feed in the midwater. Helostoma individuals produced relatively less suction than other species regardless of the food type. Helostoma produced a much larger gape and more premaxillary protrusion than other species, but also took longer to do so. We suggest that the jaw morphology of Helostoma facilitates an extremely large mouth-gape to enhance substrate-scraping. The large amplitude mouth-opening that characterizes substrate-feeding may represent a functional trade-off, whereby the enhanced ability to procure food from the substrate is accompanied by a concomitant reduction in the ability to produce suction.

  6. Are kissing gourami specialized for substrate-feeding? Prey capture kinematics of Helostoma temminckii and other anabantoid fishes.

    PubMed

    Ferry, Lara A; Konow, Nicolai; Gibb, Alice C

    2012-11-01

    Helostoma temminckii are known for a "kissing" behavior, which is often used in intraspecific interactions, and an unusual cranial morphology that is characterized by an intramandibular joint (IMJ). The IMJ is located within the lower jaw and aids in generating the eponymous kissing movement. In other teleost linages the IMJ is associated with the adoption of a substrate-grazing foraging habit. However, because of anatomical modifications of the gill-rakers, Helostoma has been considered a midwater filter-feeding species. We offered midwater, benthic, and attached food to Helostoma, Betta, and two "true" osphronemid gouramis, to ask: (1) how do food capture kinematics differ in different foraging contexts; and (2) are Helostoma feeding kinematics distinct when compared with closely related anabantoids that lack an IMJ? For all anabantoid species except Helostoma, benthic prey were captured using a greater contribution of effective suction relative to midwater prey, though Helostoma was rarely willing to feed in the midwater. Helostoma individuals produced relatively less suction than other species regardless of the food type. Helostoma produced a much larger gape and more premaxillary protrusion than other species, but also took longer to do so. We suggest that the jaw morphology of Helostoma facilitates an extremely large mouth-gape to enhance substrate-scraping. The large amplitude mouth-opening that characterizes substrate-feeding may represent a functional trade-off, whereby the enhanced ability to procure food from the substrate is accompanied by a concomitant reduction in the ability to produce suction. PMID:22952136

  7. Feeding ecology of some fish species occurring in artisanal fishery of Socotra Island (Yemen).

    PubMed

    Hassan Ali', Mohammed Kaed; Belluscio, Andrea; Ventura, Daniele; Ardizzone, Giandomenico

    2016-04-30

    The demersal species Lethrinus borbonicus, Lethrinus mahsena, Lethrinus microdon, Lethrinus nebulosus, Lutjanus bohar, Lutjanus gibbus, Lutjanus kasmira, Epinephelus fasciatus, Epinephelus stoliczkae, Carangoides gymnostethus and Euthynnus affinis are important coastal fishes species of the northern coast of Socotra (Yemen), exploited by local fishery. The biology and feeding ecology of these species are poorly known in the area. A total of 1239 specimens were sampled from the main fishing landing site of the island (Hadibo). Total length and weight were measured, stomach contents were analyzed, diet overlap, Fulton's Condition index, and trophic levels were estimated. C. gymnostethus, L. microdon and L. kasmira occupied the highest position (T=4.50), L. nebulosus occupied the lower one (TL=3.41). The role of the increasing abundance of small pelagic fish in the diet of many species after the upwelling event is evident, but also different feeding strategies are reported, according to fish ecology.

  8. Food and feeding of fish in Hartwell Reservoir tailwater, Georgia-South Carolina

    USGS Publications Warehouse

    Barwick, D. Hugh; Hudson, Patrick L.

    1985-01-01

    Food of silver redhorse (Moxostoma anisurum), redbreast sunfish (Lepomis auritus), green sunfish (L. cyanellus), and bluegills (L. macrochirus) was examined to determine whether or not these fish in the Hartwell Reservoir tailwater (Savannah River, Georgia-South Carolina) ate organisms entrained from the reservoir or displaced from the tailwater during water releases associated with the production of hydropower. These fish fed primarily on aquatic insects, crayfish, and terrestrial organisms originating from the tailwater. Major periods of feeding occurred during nongeneration.

  9. Use of a gyroscope/accelerometer data logger to identify alternative feeding behaviours in fish.

    PubMed

    Kawabata, Yuuki; Noda, Takuji; Nakashima, Yuuki; Nanami, Atsushi; Sato, Taku; Takebe, Takayuki; Mitamura, Hiromichi; Arai, Nobuaki; Yamaguchi, Tomofumi; Soyano, Kiyoshi

    2014-09-15

    We examined whether we could identify the feeding behaviours of the trophic generalist fish Epinephelus ongus on different prey types (crabs and fish) using a data logger that incorporated a three-axis gyroscope and a three-axis accelerometer. Feeding behaviours and other burst behaviours, including escape responses, intraspecific interactions and routine movements, were recorded from six E. ongus individuals using data loggers sampling at 200 Hz, and were validated by simultaneously recorded video images. For each data-logger record, we extracted 5 s of data when any of the three-axis accelerations exceeded absolute 2.0 g, to capture all feeding behaviours and other burst behaviours. Each feeding behaviour was then identified using a combination of parameters that were derived from the extracted data. Using decision trees with the parameters, high true identification rates (87.5% for both feeding behaviours) with low false identification rates (5% for crab-eating and 6.3% for fish-eating) were achieved for both feeding behaviours.

  10. Use of a gyroscope/accelerometer data logger to identify alternative feeding behaviours in fish.

    PubMed

    Kawabata, Yuuki; Noda, Takuji; Nakashima, Yuuki; Nanami, Atsushi; Sato, Taku; Takebe, Takayuki; Mitamura, Hiromichi; Arai, Nobuaki; Yamaguchi, Tomofumi; Soyano, Kiyoshi

    2014-09-15

    We examined whether we could identify the feeding behaviours of the trophic generalist fish Epinephelus ongus on different prey types (crabs and fish) using a data logger that incorporated a three-axis gyroscope and a three-axis accelerometer. Feeding behaviours and other burst behaviours, including escape responses, intraspecific interactions and routine movements, were recorded from six E. ongus individuals using data loggers sampling at 200 Hz, and were validated by simultaneously recorded video images. For each data-logger record, we extracted 5 s of data when any of the three-axis accelerations exceeded absolute 2.0 g, to capture all feeding behaviours and other burst behaviours. Each feeding behaviour was then identified using a combination of parameters that were derived from the extracted data. Using decision trees with the parameters, high true identification rates (87.5% for both feeding behaviours) with low false identification rates (5% for crab-eating and 6.3% for fish-eating) were achieved for both feeding behaviours. PMID:25013109

  11. Social interactions can affect feeding behaviour of fish in tanks

    NASA Astrophysics Data System (ADS)

    Kooijman, S. A. L. M.

    2009-08-01

    Fish from the same clutch of eggs, so of the same age and family, can differ substantially in size after some time in a tank as result of social interactions. On the basis of computer simulation studies I here demonstrate that it is possible to mimic this empirical observation using the rules of the standard Dynamic Energy Budget (DEB) model, supplemented with a simple stochastic module for interaction between individuals that have identical parameters. The remarkable result is that length-at-age of two individuals in a tank where the number of food particles is kept constant closely follows von Bertalanffy growth curves with very different parameters, while in reality the individuals have identical parameters. The empirical observation demonstrates that fish are close to the supply end of the supply-demand spectrum and that age-based models for growth don't apply to supply systems. The significance of the result is discussed.

  12. Trophic transfer of sediment-associated polychlorinated biphenyls from meiobenthos to bottom-feeding fish

    SciTech Connect

    DiPinto, L.M.; Coull, B.C.

    1997-12-01

    Experiments were conducted to examine the dynamics of the sediment-associated polychlorinated biphenyl (PCB) using a benthic-based trophic transfer model (sediments to benthic copepods to juvenile fish). Field-collected benthic copepods were exposed to sublethal levels of PCB in sediments for 96 h. Accumulation of PCB was measured in the copepods, and these contaminated copepods were fed to the juvenile fish predator Leiostomus xanthurus in uncontaminated sediments. After gut clearance, whole fish were homogenized and examined for PCB accumulation. Similar experiments with L. xanthurus in which meals of uncontaminated copepods were fed in PCB-contaminated sediments were conducted to determine the relative roles of contaminated sediments and contaminated copepod prey ingestion to PCB transfer. Total PCB transfer as well as PCB congener group contributions were examined. A total of 30 congeners were grouped according to log K{sub ow} increments and according to chlorine homologue groups. Copepods exposed to PCB-contaminated sediments to 90 {micro}g/g accumulated PCBs to 326 {micro}g/g dry weight. Accumulation of PCB in fish feeding in contaminated sediments was five times higher than that in fish feeding on contaminated prey in uncontaminated sediments (p = 0.0498). In terms of congener patterns, log K{sub ow} grouping provided clearer discrimination between groups. Congener patterns were similar in PCB stock solution, sediments, and copepods and were different in the two fish treatments. K{sub ow} group relative accumulation patterns in fish were mixed. The chlorine homologue groups revealed that the fish preferentially accumulated the tetrachlorinated congeners relative to copepods and sediments.

  13. Detection of artificial water flows by the lateral line system of a benthic feeding cichlid fish.

    PubMed

    Schwalbe, Margot A B; Sevey, Benjamin J; Webb, Jacqueline F

    2016-04-01

    The mechanosensory lateral line system of fishes detects water motions within a few body lengths of the source. Several types of artificial stimuli have been used to probe lateral line function in the laboratory, but few studies have investigated the role of flow sensing in benthic feeding teleosts. In this study, we used artificial flows emerging from a sandy substrate to assess the contribution of flow sensing to prey detection in the peacock cichlid, Aulonocara stuartgranti, which feeds on benthic invertebrates in Lake Malawi. Using a positive reinforcement protocol, we trained fish to respond to flows lacking the visual and chemical cues generated by tethered prey in prior studies with A. stuartgranti Fish successfully responded to artificial flows at all five rates presented (characterized using digital particle image velocimetry), and showed a range of flow-sensing behaviors, including an unconditioned bite response. Immediately after lateral line inactivation, fish rarely responded to flows and the loss of vital fluorescent staining of hair cells (with 4-di-2-ASP) verified lateral line inactivation. Within 2 days post-treatment, some aspects of flow-sensing behavior returned and after 7 days, flow-sensing behavior and hair cell fluorescence both returned to pre-treatment levels, which is consistent with the reported timing of hair cell regeneration in other vertebrates. The presentation of ecologically relevant water flows to assess flow-sensing behaviors and the use of a positive reinforcement protocol are methods that present new opportunities to study the role of flow sensing in the feeding ecology of benthic feeding fishes. PMID:27030780

  14. How to capture fish in a school? Effect of successive predator attacks on seabird feeding success.

    PubMed

    Thiebault, Andréa; Semeria, Magali; Lett, Christophe; Tremblay, Yann

    2016-01-01

    Prey aggregations, such as fish schools, attract numerous predators. This typically leads to the formation of multispecific groups of predators. These aggregations can be seen both as a place of increased competition and as a place of possible facilitation between predators. Consequently, the functional role of such predator-prey aggregation is uncertain, and its effect on individual feeding success is virtually unknown. Using underwater film footage of different predators feeding on fish schools during the sardine run in South Africa, we directly measured the in situ feeding success of individual Cape gannets Morus capensis in different foraging situations. We determined the types of Cape gannet attacks (direct plunge dive or plunge dive followed by underwater pursuit) and we measured the occurrences and timing of attacks from the different species (mostly Cape gannets and long-beaked common dolphins Delphinus capensis). We also estimated the size of the targeted fish schools. These observations were complemented with a simulation model to evaluate the cumulative effect of successive predator attacks on the prey aggregation structure. The probability to capture a fish in one feeding attempt by Cape gannets averaged 0·28. It was lower when gannets engaged in underwater prey pursuit after the plunge compared to direct plunge (0·13 vs. 0·36). We found no effect of the number of prey on gannets' feeding success. However, the timing and frequency of attacks influenced strongly and positively the feeding success of individuals. The probability to capture a fish was the lowest (0·16) when no attack occurred in the few seconds (1-15 s) prior to a dive and the highest (˜0·4, i.e. more than twice) when one or two attacks occurred during this time window. The simulation model showed that a prey aggregation disorganized just after an attack and that the maximum of disturbance was obtained a few seconds after the initiation of the successive attacks. Our study suggests

  15. Feeding habits and habitats preferences affecting mercury bioaccumulation in 37 subtropical fish species from Wujiang River, China.

    PubMed

    Li, Sixin; Zhou, Lianfeng; Wang, Hongjun; Liang, Youguang; Chang, Jianbo; Xiong, Meihua; Zhang, Yichao; Hu, Juxiang

    2009-02-01

    The present study is the first to report the total mercury concentration of 37 fish species collected from Wujiang River, which is the largest branch on the southern bank of Yangtze River, China and proposed for hydropower development. Total mercury concentrations varied among the 37 subtropical species examined. We found higher mercury concentrations in carnivorous species demonstrating greater mercury bioaccumulation in species with more predatory feeding habits. There is no significant difference between fish grouped by habitat preference and feeding habit. However, carnivorous species preferring benthic positions had higher total mercury concentrations than others suggesting that mercury accumulation is related to the interaction of feeding habit and habitat preference. In our study, fish that are bottom living and feed on other fish or aquatic animals are more likely at high risk of mercury exposure. Additional mercury contamination and future impoundment may raise mercury concentration in fish in the Wujiang causing concern for human health and ecological impacts.

  16. Food Selectivity and Diet Switch Can Explain the Slow Feeding of Herbivorous Coral-Reef Fishes during the Morning

    PubMed Central

    Khait, Ruth; Obolski, Uri; Hadany, Lilach; Genin, Amatzia

    2013-01-01

    Most herbivorous coral-reef fishes feed slower in the morning than in the afternoon. Given the typical scarcity of algae in coral reefs, this behavior seems maladaptive. Here we suggest that the fishes' slow feeding during the morning is an outcome of highly selective feeding on scarcely found green algae. The rarity of the food requires longer search time and extended swimming tracks, resulting in lower bite rates. According to our findings by noon the fish seem to stop their search and switch to indiscriminative consumption of benthic algae, resulting in apparent higher feeding rates. The abundance of the rare preferable algae gradually declines from morning to noon and seems to reach its lowest levels around the switch time. Using in situ experiments we found that the feeding pattern is flexible, with the fish exhibiting fast feeding rates when presented with ample supply of preferable algae, regardless of the time of day. Analyses of the fish's esophagus content corroborated our conclusion that their feeding was highly selective in the morning and non-selective in the afternoon. Modeling of the fishes' behavior predicted that the fish should perform a diel diet shift when the preferred food is relatively rare, a situation common in most coral reefs found in a warm, oligotrophic ocean. PMID:24358178

  17. Study of mechanical effects on the quality of fish feed during different stages of manufacturing.

    PubMed

    Patwary, Y A; Sarker, B S; Belal Hossain, M; Minar, M H; Shamsuddin, M

    2013-09-01

    Successful aquaculture highly depends on ensuring the quality feed which mostly depends on the proper feedstuffs selection and the manufacturing process. This study was undertaken to monitor the deviation of protein level and the mechanical effects on different biofactors viz. protein, moisture, ash, crude lipid and fiber in feed during manufacture. Samples were collected at randomly and batch wise from the prominent feed industry during the production period. Samples were collected from two different production level viz. 'Final Mixer' and 'Finished Feed' and third other sample was prepared as 'Control Mixer' on the dry basis. All the samples were analyzed by using proper analytical procedure in the laboratory of fish nutrition. The percentage of protein content was 17.9 in control mixer and 18.46 in final mixer which finally decreased to 17.03% in finished feed. In control mixer ash content was 25.74 and 23.1% in final mixer which increased in finished feed to 24.68%. Lipid content increased in finished feed (6.1%) rather than the final mixer (5.95%) and the control mixer (3.75%). However, crude fiber content decreased from control mixer to finished feed thoroughly. Crude fiber content in control mixer was 7.4% which decreased to 6.86 and 6.56% in final mixer and finished feed respectively. Again a relation may be drawn between the moisture content and ash and lipid content with crude fiber. By this study it was observed quality of feed is highly influenced by quality machine.

  18. A trait-based approach reveals the feeding selectivity of a small endangered Mediterranean fish.

    PubMed

    Rodríguez-Lozano, Pablo; Verkaik, Iraima; Maceda-Veiga, Alberto; Monroy, Mario; de Sostoa, Adolf; Rieradevall, Maria; Prat, Narcís

    2016-05-01

    Functional traits are growing in popularity in modern ecology, but feeding studies remain primarily rooted in a taxonomic-based perspective. However, consumers do not have any reason to select their prey using a taxonomic criterion, and prey assemblages are variable in space and time, which makes taxon-based studies assemblage-specific. To illustrate the benefits of the trait-based approach to assessing food choice, we studied the feeding ecology of the endangered freshwater fish Barbus meridionalis. We hypothesized that B. meridionalis is a selective predator which food choice depends on several prey morphological and behavioral traits, and thus, its top-down pressure may lead to changes in the functional composition of in-stream macroinvertebrate communities. Feeding selectivity was inferred by comparing taxonomic and functional composition (13 traits) between ingested and free-living potential prey using the Jacob's electivity index. Our results showed that the fish diet was influenced by 10 of the 13 traits tested. Barbus meridionalis preferred prey with a potential size of 5-10 mm, with a medium-high drift tendency, and that drift during daylight. Potential prey with no body flexibility, conical shape, concealment traits (presence of nets and/or cases, or patterned coloration), and high aggregation tendency had a low predation risk. Similarly, surface swimmers and interstitial taxa were low vulnerable to predation. Feeding selectivity altered the functional composition of the macroinvertebrate communities. Fish absence favored taxa with weak aggregation tendency, weak flexibility, and a relatively large size (10-20 mm of potential size). Besides, predatory invertebrates may increase in fish absence. In conclusion, our study shows that the incorporation of the trait-based approach in diet studies is a promising avenue to improve our mechanistic understanding of predator-prey interactions and to help predict the ecological outcomes of predator invasions and

  19. Feeding characteristics reveal functional distinctions among browsing herbivorous fishes on coral reefs

    NASA Astrophysics Data System (ADS)

    Streit, Robert P.; Hoey, Andrew S.; Bellwood, David R.

    2015-12-01

    The removal of macroalgal biomass by fishes is a key process on coral reefs. Numerous studies have identified the fish species responsible for removing mature macroalgae, and have identified how this varies spatially, temporally, and among different algal types. None, however, have considered the behavioural and morphological traits of the browsing fishes and how this may influence the removal of macroalgal material. Using video observations of fish feeding on the brown macroalga Sargassum polycystum, we quantified the feeding behaviour and morphology of the four dominant browsing species on the Great Barrier Reef ( Kyphosus vaigiensis, Naso unicornis, Siganus canaliculatus, and Siganus doliatus). The greatest distinction between species was the algal material they targeted. K. vaigiensis and N. unicornis bit on the entire macroalgal thallus in approximately 90 % of bites. In contrast, Si. canaliculatus and Si. doliatus avoided biting the stalks, with 80-98 % of bites being on the macroalgal leaves only. This distinctive grouping into `entire thallus-biters' versus `leaf-biters' was not supported by size-standardized measures of biting morphology. Rather, species-specific adult body sizes, tooth shape, and feeding behaviour appear to underpin this functional distinction, with adults of the two larger fish species ( N. unicornis and K. vaigiensis) eating the entire macroalgal thallus, while the two smaller species ( Si. canaliculatus and Si. doliatus) bite only leaves. These findings caution against assumed homogeneity within this, and potentially other, functional groups on coral reefs. As functional redundancy within the macroalgal browsers is limited, the smaller `leaf-biting' species are unlikely to be able to compensate functionally for the loss of larger `entire thallus-biting' species.

  20. Development and validation of a high performance liquid chromatography assay for 17alpha-methyltestosterone in fish feed.

    PubMed

    Marwah, Ashok; Marwah, Padma; Lardy, Henry

    2005-09-25

    17alpha-Methyltestosterone (MT) is used to manipulate the gender of a variety of fish species. A high performance liquid chromatography (HPLC) internal standard method for the determination of 17alpha-methyltestosterone in fish feed using 3beta-methoxy-17beta-hydroxyandrost-5-en-7-one as internal standard (IS) has been developed. The method has been validated for the quantitation of MT in fish feed using 245 nm UV absorbance as the parent wavelength and 255 nm as a qualifier wavelength. The method was validated in the concentration range of 15.0-120 mg/kg of 17alpha-methyltestosterone in fish feed. Method was also found to be suitable for other feeds.

  1. Tropical agricultural residues and their potential uses in fish feeds: the Costa Rican situation.

    PubMed

    Ulloa, J B; van Weerd, J H; Huisman, E A; Verreth, J A J

    2004-01-01

    In Costa Rica as many other tropical countries, the disposal problem of agricultural wastes is widely recognized but efforts to find solutions are not equal for different sectors. This study describes the situation of major agricultural residues in Costa Rica, identifying the activities with higher amounts produced and, the potential use of these residues in fish feeds. In Costa Rica, during the 1993-1994 production season, major agricultural sectors (crop and livestock) generated a total amount of 3.15-3.25 million MT of residues (classified in by-products: used residues and wastes: not used residues). Some residues are treated to turn them into valuable items or to diminish their polluting effects (e.g., the so-called by-products). About 1.56-1.63 million MT of by-products were used for different purposes (e.g. fertilization, animal feeding, fuel, substrates in greenhouses). However, the remainder (1.59-1.62 million MT) was discharged into environment causing pollution. About 1.07-1.2 million MT wastes came from major crop systems (banana, coffee, sugarcane and oil palm) whereas the remainder came from animal production systems (porcine and poultry production, slaughtering). These data are further compared to residues estimates for the 2001-2002 production season coming from the biggest crops activities. Unfortunately, most of the studied wastes contain high levels of moisture and low levels of protein, and also contain variable amounts of antinutritional factors (e.g., polyphenols, tannins, caffeine), high fibre levels and some toxic substances and pesticides. All these reasons may limit the use of these agricultural wastes for animal feeding, especially in fish feeds. The potential use of the major vegetable and animal residues in fish feeds is discussed based on their nutritional composition, on their amount available over the year and on their pollution risks. Other constraints to use these wastes in fish feeds are the extra costs of drying and, in most cases

  2. Tropical agricultural residues and their potential uses in fish feeds: the Costa Rican situation.

    PubMed

    Ulloa, J B; van Weerd, J H; Huisman, E A; Verreth, J A J

    2004-01-01

    In Costa Rica as many other tropical countries, the disposal problem of agricultural wastes is widely recognized but efforts to find solutions are not equal for different sectors. This study describes the situation of major agricultural residues in Costa Rica, identifying the activities with higher amounts produced and, the potential use of these residues in fish feeds. In Costa Rica, during the 1993-1994 production season, major agricultural sectors (crop and livestock) generated a total amount of 3.15-3.25 million MT of residues (classified in by-products: used residues and wastes: not used residues). Some residues are treated to turn them into valuable items or to diminish their polluting effects (e.g., the so-called by-products). About 1.56-1.63 million MT of by-products were used for different purposes (e.g. fertilization, animal feeding, fuel, substrates in greenhouses). However, the remainder (1.59-1.62 million MT) was discharged into environment causing pollution. About 1.07-1.2 million MT wastes came from major crop systems (banana, coffee, sugarcane and oil palm) whereas the remainder came from animal production systems (porcine and poultry production, slaughtering). These data are further compared to residues estimates for the 2001-2002 production season coming from the biggest crops activities. Unfortunately, most of the studied wastes contain high levels of moisture and low levels of protein, and also contain variable amounts of antinutritional factors (e.g., polyphenols, tannins, caffeine), high fibre levels and some toxic substances and pesticides. All these reasons may limit the use of these agricultural wastes for animal feeding, especially in fish feeds. The potential use of the major vegetable and animal residues in fish feeds is discussed based on their nutritional composition, on their amount available over the year and on their pollution risks. Other constraints to use these wastes in fish feeds are the extra costs of drying and, in most cases

  3. Feeding ecology of elasmobranch fishes in coastal waters of the Colombian Eastern Tropical Pacific

    PubMed Central

    Navia, Andrés F; Mejía-Falla, Paola A; Giraldo, Alan

    2007-01-01

    Background Stomach contents of 131 specimens of five elasmobranch species (Mustelus lunulatus, Dasyatis longa, Rhinobatos leucorhynchus, Raja velezi and Zapteryx xyster) caught in the central fishing zone in the Pacific Ocean of Colombia were counted and weighed to describe feeding habits and dietary overlaps. Results Twenty-one prey items belonging to four major groups (stomatopods, decapods, mollusks and fish) were identified. Decapod crustaceans were the most abundant prey found in stomachs. The mantis shrimp Squilla panamensis was the main prey item in the diet of M. lunulatus; tiger shrimp Trachypenaeus sp. was the main prey item in the diet of Rhinobatos leucorhynchus and Raja velezi, and Penaeidae shrimp were the main prey items in the diet of Z. xyster. Furthermore, fish were important in the diet of Raja velezi, Z. xyster and D. longa. The greatest diet breadth corresponded to Z. xyster whereas M. lunulatus was the most specialized predator. Finally, four significant diet overlaps between the five species were found, attributable mainly to Squillidae, Penaeidae and Fish. Conclusion Shrimps (Penaeidae and stomatopods) and benthic fishes were the most important food types in the diet of the elasmobranch species studied. Diet breadth and overlap were relatively low. Determination of food resource partitioning among the batoid species studied was not possible. However, we identified partitions in other niche axes (time of feeding activity and habitat utilization). It is possible to assume that diffuse competition could be exceeding the biunivocal competition among the studied species. Therefore, this assemblage would have a strong tendency to trophic guild formation. PMID:17877796

  4. Phosphorus Loadings Associated with a Park Tourist Attraction: Limnological Consequences of Feeding the Fish

    NASA Astrophysics Data System (ADS)

    Turner, Andrew M.; Ruhl, Nathan

    2007-04-01

    The Linesville spillway of Pymatuning State Park is one of the most visited tourist attractions in Pennsylvania, USA, averaging more than 450,000 visitors · year-1. Carp ( Cyprinus carpio Linnaeus) and waterfowl congregate at the spillway where they are fed bread and other foods by park visitors. We hypothesized that the “breadthrowers” constitute a significant nutrient vector to the upper portion of Pymatuning Reservoir. In the summer of 2002, we estimated phosphorus loadings attributable to breadthrowers, and compared these values to background loadings from Linesville Creek, a major tributary to the upper reservoir. Items fed to fish included bread, donuts, bagels, canned corn, popcorn, corn chips, hot dogs, birthday cakes, and dog food. Phosphorus loading associated with park visitors feeding fish was estimated to be 3233 g day-1, and estimated P export from the Linesville Creek watershed was 2235 g·day-1. P loading attributable to breadthrowers exceeded that of the entire Linesville Creek watershed on 33 of the 35 days of study, with only a heavy rainfall event triggering watershed exports that exceeded spillway contributions. Averaged across 5 weeks, breadthrowers contributed 1.45-fold more P to Pymatuning Reservoir than the Linesville Creek watershed. If Linesville Creek P exports are extrapolated to the entire Sanctuary Lake watershed, spillway contributions of P added 48% to the non-point source watershed P entering the lake. Park visitors feeding fish at the Linesville Spillway are a significant source of nutrients entering Sanctuary Lake.

  5. Monitoring escape and feeding behaviours of cruiser fish by inertial and magnetic sensors.

    PubMed

    Noda, Takuji; Kawabata, Yuuki; Arai, Nobuaki; Mitamura, Hiromichi; Watanabe, Shun

    2013-01-01

    A method was developed and applied for monitoring two types of fast-start locomotion (feeding and escape) of a cruiser fish, Japanese amberjacks Seriola quinqueradiata. A data logger, which incorporated a 3-axis gyroscope, a 3-axis accelerometer and a 3-axis magnetometer, was attached to the five fish. The escape, feeding and routine movements of the fish, which were triggered in tank experiments, were then recorded by the data logger and video cameras. The locomotor variables, calculated based on the high resolution measurements by the data logger (500 Hz), were investigated to accurately detect and classify the types of fast-track behaviour. The results show that fast-start locomotion can be detected with a high precision (0.97) and recall rate (0.96) from the routine movements. Two types of fast-start movements were classified with high accuracy (0.84). Accuracy was greater if the data were obtained from the data logger, which combined an accelerometer, a gyroscope and a magnetometer, than if only an accelerometer (0.80) or a gyroscope (0.66) was used. PMID:24236126

  6. Phosphorus loadings associated with a park tourist attraction: limnological consequences of feeding the fish.

    PubMed

    Turner, Andrew M; Ruhl, Nathan

    2007-04-01

    The Linesville spillway of Pymatuning State Park is one of the most visited tourist attractions in Pennsylvania, USA, averaging more than 450,000 visitors . year(-1). Carp (Cyprinus carpio Linnaeus) and waterfowl congregate at the spillway where they are fed bread and other foods by park visitors. We hypothesized that the "breadthrowers" constitute a significant nutrient vector to the upper portion of Pymatuning Reservoir. In the summer of 2002, we estimated phosphorus loadings attributable to breadthrowers, and compared these values to background loadings from Linesville Creek, a major tributary to the upper reservoir. Items fed to fish included bread, donuts, bagels, canned corn, popcorn, corn chips, hot dogs, birthday cakes, and dog food. Phosphorus loading associated with park visitors feeding fish was estimated to be 3233 g day(-1), and estimated P export from the Linesville Creek watershed was 2235 g.day(-1). P loading attributable to breadthrowers exceeded that of the entire Linesville Creek watershed on 33 of the 35 days of study, with only a heavy rainfall event triggering watershed exports that exceeded spillway contributions. Averaged across 5 weeks, breadthrowers contributed 1.45-fold more P to Pymatuning Reservoir than the Linesville Creek watershed. If Linesville Creek P exports are extrapolated to the entire Sanctuary Lake watershed, spillway contributions of P added 48% to the non-point source watershed P entering the lake. Park visitors feeding fish at the Linesville Spillway are a significant source of nutrients entering Sanctuary Lake.

  7. Changes in the trophic status of fish feeding guilds in response to flow modification

    NASA Astrophysics Data System (ADS)

    Delong, M. D.; Thoms, M. C.

    2016-03-01

    Rivers are among the most extensively modified ecosystems globally. Identifying linkages between critical drivers of change and ecological response is challenging because of the myriad of ways rivers are modified. This study examines longer-term relationships (>70 years) between the trophic status of fish and historical flow changes in rivers of the Mississippi Basin. The flow regime of each river is regulated but differs in terms of character of hydrological modification. Tissue samples from specimens obtained from museum collections were used for determination of carbon and nitrogen stable isotope ratios. Questions asked were as follows: (1) Are there differences in stable isotope ratios of fish feeding guilds prior to and following hydrological modification? (2) What hydrological attributes are associated with isotopic changes? And (3) are corresponding changes in stable isotope ratios and hydrology identifiable across different spatial scales? Significant and sustained changes in stable isotope ratios of fish feeding guilds occurred immediately following flow regulation in all rivers. These changes were not associated with human-induced biogeochemical alterations. The subsequent response was complex because (1) different guilds exhibited pronounced shifts in isotopic ratios, (2) hydrological modification differed between rivers, and (3) differences in stable isotopic ratios varied between spatial scales.

  8. "Who's been feeding in my bed?" Benthivorous fish affect fluvial sediment transport - fact or fairy tale?

    NASA Astrophysics Data System (ADS)

    Rice, Stephen; Pledger, Andrew; Smith, James; Toone, Julia

    2016-04-01

    Many species of fish are benthivorous - they forage for food in the river bed - and their foraging disturbs, displaces and sorts bed materials with implications for fluvial sediment transport. Flume experiments have confirmed that benthic foraging by Barbel (Barbus barbus (L.)) and Chub (Squalius cephalus (L.)) modifies the structure and topography of water-worked gravels, thereby increasing particle entrainment probabilities and the quantity of sediment mobilised during experimental high flows. Field experiments and observations have demonstrated the impact of foraging on patch-scale bed disturbance, gravel structure, grain displacements and grain-size sorting. Initial ex-situ experiments support the suggestion that in low gradient rivers, shoals of fish like Bream (Abramis brama (L.)) entrain fine bed sediments, adding a biotic surcharge to the suspended sediment flux and modifying bed topography. These results underpin a novel proposal: that there is an aggregate, cumulative effect of benthic foraging on fluvial sediment transport at larger scales, including at scales where the contribution to sediment movement and river channel behaviour generates management concerns. Evaluating this proposal is a long-term goal, which is based on two intermediate objectives: to develop deeper mechanistic understanding of foraging impacts and to establish the spatial and temporal extent of geomorphologically significant feeding behaviours in river systems. The latter is crucial because field data are currently limited to a single reach on one UK river. It is reasonable to hypothesise that foraging impacts are spatially and temporally widespread because obligate and opportunistic benthic feeding is common and fish feed throughout their life. However, the effectiveness of foraging as a geomorphological process is likely to vary with factors including substrate size, fish community composition, food availability, water temperature, river flows and seasonal changes in fish

  9. Comparison of remote video and diver's direct observations to quantify reef fishes feeding on benthos in coral and rocky reefs.

    PubMed

    Longo, G O; Floeter, S R

    2012-10-01

    This study compared remote underwater video and traditional direct diver observations to assess reef fish feeding impact on benthos across multiple functional groups within different trophic categories (e.g. herbivores, zoobenthivores and omnivores) and in two distinct reef systems: a subtropical rocky reef and a tropical coral reef. The two techniques were roughly equivalent, both detecting the species with higher feeding impact and recording similar bite rates, suggesting that reef fish feeding behaviour at the study areas are not strongly affected by the diver's presence. PMID:23020575

  10. Comparison of remote video and diver's direct observations to quantify reef fishes feeding on benthos in coral and rocky reefs.

    PubMed

    Longo, G O; Floeter, S R

    2012-10-01

    This study compared remote underwater video and traditional direct diver observations to assess reef fish feeding impact on benthos across multiple functional groups within different trophic categories (e.g. herbivores, zoobenthivores and omnivores) and in two distinct reef systems: a subtropical rocky reef and a tropical coral reef. The two techniques were roughly equivalent, both detecting the species with higher feeding impact and recording similar bite rates, suggesting that reef fish feeding behaviour at the study areas are not strongly affected by the diver's presence.

  11. Diet and feeding strategies of mesopelagic fishes in the western Mediterranean

    NASA Astrophysics Data System (ADS)

    Bernal, Ainhoa; Olivar, M. Pilar; Maynou, Francesc; Fernández de Puelles, M. Luz

    2015-06-01

    Myctophids, gonostomatids and sternoptychids are the most abundant teleosteans worldwide and constitute an important assemblage of the mesopelagic ecosystem, functioning as vehicles of energy and matter through trophic webs. This study concentrates on the trophic ecology of the most abundant mesopelagic fishes of the western Mediterranean (WM) based on stomach content analysis. The myctophids (in this study: Benthosema glaciale, Ceratoscopelus maderensis, Lobianchia dofleini, Myctophum punctatum, Hygophum benoiti, Hygophum hygomii, Lampanyctus crocodilus, Lampanyctus pusillus and Notoscopelus elongatus) perform extensive diel migrations across the water column, between the surface to as deep as 1000 m, interacting with plankton and micronekton at multiple depths, and generally feeding in the epipelagic layers at night. In contrast, the gonostomatids Cyclothone braueri, Cyclothone pygmaea, and the sternoptychid Argyropelecus hemigymnus remain below epipelagic layers, feeding at different times throughout the day and night. The diet composition, trophic niche breadth and prey selectivity of 11 of these fish species were determined for juvenile and adult individuals from two surveys performed in December 2009 and July 2010 in the western Mediterranean Sea. The number of prey items varied among species, e.g. Myctophum punctatum was the species with the highest feeding intensity, reaching ca. 700 prey items in a stomach, whereas the mean number of prey in Cyclothone braueri was low (usually 1 or 2 prey per stomach). A dietary shift towards larger prey was evident from juveniles to the largest and oldest adult individuals, despite trophic niche breadths did not increase with body length for any of these mesopelagic species. The diets of the small gonostomatids, sternoptychid and early juveniles of myctophids were dominated by non-calanoid copepods, ostracods, and other small zooplankton, whereas medium-sized myctophids, e.g. L. dofleini or H. benoiti, preyed mainly on

  12. Phytoremediation of aquaculture wastewater for water recycling and production of fish feed.

    PubMed

    Ghaly, A E; Kamal, M; Mahmoud, N S

    2005-01-01

    Five plants were examined for their ability to remove nutrients from aquaculture wastewater and suitability as fish feed: alfalfa, white clover, oat, fall rye, barley. The seeds were first germinated in water in a hydroponic system, and the plants were fed wastewater from Tilapia production facility. Clover and alfalfa seeds were infected with fungus shortly after germination, and their roots were completely destroyed by day 14. Oat, rye and barley had the fastest growth and showed greater tolerance to fungal disease compared with alfalfa and clover. Although substantial amounts of soluble and insoluble substances were released by the seeds during the germination period, the plants were able to remove all the pollutants in wastewater and significant portions of those released substances. The total reductions in total solids, COD, NO3-N, NO2-N, phosphate and potassium ranged from 54.7% to 91.0%, 56.0% to 91.5%, 82.9% to 98.1%, 95.9% to 99.5%, 54.5% to 93.6% and 99.6% to 99.8%, respectively. Oat, barley and rye grow well in this type of hydroponic system and can be used as a fish feed after being supplemented with fat, Ca, Na, Mn and Fe. Oil seeds and the chlorides of these elements could be added to these plants when formulating the fish feed. For a continuous operation, a two-unit system could be configured to allow for one week germination and one week cleaning and startup in one unit while the other unit is in operation. PMID:15607774

  13. Use of computational fluid dynamics to study forces exerted on prey by aquatic suction feeders

    PubMed Central

    Skorczewski, Tyler; Cheer, Angela; Cheung, Samson; Wainwright, Peter C.

    2010-01-01

    Suction feeding is the most commonly used mechanism of prey capture among aquatic vertebrates. Most previous models of the fluid flow caused by suction feeders involve making several untested assumptions. In this paper, a Chimera overset grids approach is used to solve the governing equations of fluid dynamics in order to investigate the assumptions that prey do not interact with the flow and that the flow can be modelled as a one-dimensional flow. Results show that, for small prey, both neglecting the prey and considering prey interaction give similar calculated forces exerted on the prey. However, as the prey item increases in size toward the size of the gape, its effect on the flow becomes more pronounced. This in turn affects both the magnitude of the hydrodynamic forces imparted to the prey and the time when maximum force is delivered. Maximum force is delivered most quickly to intermediate sized prey, about one-third of mouth diameter, and most slowly to prey less than 7 per cent or greater than 67 per cent of mouth diameter. This suggests that the effect of prey size on the timing of suction forces may have substantial consequences for the feeding ecology of suction feeders that are known to prefer prey between 25 and 50 per cent of mouth diameter. Moreover, for a 15 cm fish with a 15 mm gape, assuming a radial one-dimensional flow field can result in underestimating the maximum force exerted on a 5 mm diameter spherical prey 1 gape distance from the mouth by up to 28.7 per cent. PMID:19674998

  14. Use of computational fluid dynamics to study forces exerted on prey by aquatic suction feeders.

    PubMed

    Skorczewski, Tyler; Cheer, Angela; Cheung, Samson; Wainwright, Peter C

    2010-03-01

    Suction feeding is the most commonly used mechanism of prey capture among aquatic vertebrates. Most previous models of the fluid flow caused by suction feeders involve making several untested assumptions. In this paper, a Chimera overset grids approach is used to solve the governing equations of fluid dynamics in order to investigate the assumptions that prey do not interact with the flow and that the flow can be modelled as a one-dimensional flow. Results show that, for small prey, both neglecting the prey and considering prey interaction give similar calculated forces exerted on the prey. However, as the prey item increases in size toward the size of the gape, its effect on the flow becomes more pronounced. This in turn affects both the magnitude of the hydrodynamic forces imparted to the prey and the time when maximum force is delivered. Maximum force is delivered most quickly to intermediate sized prey, about one-third of mouth diameter, and most slowly to prey less than 7 per cent or greater than 67 per cent of mouth diameter. This suggests that the effect of prey size on the timing of suction forces may have substantial consequences for the feeding ecology of suction feeders that are known to prefer prey between 25 and 50 per cent of mouth diameter. Moreover, for a 15 cm fish with a 15 mm gape, assuming a radial one-dimensional flow field can result in underestimating the maximum force exerted on a 5 mm diameter spherical prey 1 gape distance from the mouth by up to 28.7 per cent.

  15. Feeding in extinct jawless heterostracan fishes and testing scenarios of early vertebrate evolution.

    PubMed Central

    Purnell, Mark A

    2002-01-01

    How long-extinct jawless fishes fed is poorly understood, yet interpretations of feeding are an important component of many hypotheses concerning the origin and early evolution of vertebrates. Heterostracans were the most diverse clade of armoured jawless vertebrates (stem gnathostomes), and the structure of the mouth and its use in feeding are the subjects of long-standing and heated controversy. I present here evidence that heterostracan feeding structures exhibit recurrent patterns of in vivo wear, are covered internally by microscopic oral denticles, and that the mouth may have been less flexible than has been thought. These data, particularly the absence of wear at the tips of oral plates, and the evidence that the mouth was lined with delicate outwardly directed denticles, effectively falsify all but one hypothesis of feeding in heterostracans: heterostracans were microphagous suspension feeders. This has a direct bearing on hypotheses that address ecological aspects of early vertebrate diversity and evolution, contradicting the widespread view that the pattern of early vertebrate evolution reflects a long-term trend towards increasingly active and predatory habits. PMID:11788040

  16. Seagrass feeding choices and digestive strategies of the herbivorous fish Sarpa salpa.

    PubMed

    Goldenberg, S U; Erzini, K

    2014-05-01

    This is the first study investigating the plant-herbivore interaction between Sarpa salpa, which has overgrazed seagrass transplants in Portugal, and the seagrasses Cymodocea nodosa, Zostera marina and Zostera noltii, which have been considered for restoration. When offered the choice between the three seagrasses in outdoor tanks, adult S. salpa clearly preferred Z. noltii. Testing the seagrasses separately, mean ± s.d. feeding rates ranged from 21 ± 11 g seagrass fresh mass kg⁻¹ fish mass day⁻¹ for Z. marina to 32 ± 9 g seagrass fresh mass kg⁻¹ fish mass day⁻¹ for C. nodosa and 40 ± 11 g seagrass fresh mass kg⁻¹ fish mass day⁻¹ for Z. noltii (temperature = 16° C). Food-processing rate in S. salpa did not differ between seagrasses, and there was no evidence of a regulation of processing rate according to food intake. Seagrasses differed substantially in nitrogen content and C:N, with C. nodosa containing the highest nitrogen content and lowest C:N (2·5 ± 0·1% and 14·0 ± 1·0), followed by Z. noltii (2·1 ± 0·1% and 17·0 ± 1·0) and Z. marina (1·4 ± 0·1% and 26·0 ± 2·0). Food-processing rate in S. salpa and the nutritional value of the seagrasses were not correlated with the observed feeding preference and rate. The study suggests that C. nodosa and Z. marina are less at risk of overgrazing by S. salpa and might thus be preferable to Z. noltii for seagrass restoration in areas with noticeable abundances of this fish. PMID:24684485

  17. Seagrass feeding choices and digestive strategies of the herbivorous fish Sarpa salpa.

    PubMed

    Goldenberg, S U; Erzini, K

    2014-05-01

    This is the first study investigating the plant-herbivore interaction between Sarpa salpa, which has overgrazed seagrass transplants in Portugal, and the seagrasses Cymodocea nodosa, Zostera marina and Zostera noltii, which have been considered for restoration. When offered the choice between the three seagrasses in outdoor tanks, adult S. salpa clearly preferred Z. noltii. Testing the seagrasses separately, mean ± s.d. feeding rates ranged from 21 ± 11 g seagrass fresh mass kg⁻¹ fish mass day⁻¹ for Z. marina to 32 ± 9 g seagrass fresh mass kg⁻¹ fish mass day⁻¹ for C. nodosa and 40 ± 11 g seagrass fresh mass kg⁻¹ fish mass day⁻¹ for Z. noltii (temperature = 16° C). Food-processing rate in S. salpa did not differ between seagrasses, and there was no evidence of a regulation of processing rate according to food intake. Seagrasses differed substantially in nitrogen content and C:N, with C. nodosa containing the highest nitrogen content and lowest C:N (2·5 ± 0·1% and 14·0 ± 1·0), followed by Z. noltii (2·1 ± 0·1% and 17·0 ± 1·0) and Z. marina (1·4 ± 0·1% and 26·0 ± 2·0). Food-processing rate in S. salpa and the nutritional value of the seagrasses were not correlated with the observed feeding preference and rate. The study suggests that C. nodosa and Z. marina are less at risk of overgrazing by S. salpa and might thus be preferable to Z. noltii for seagrass restoration in areas with noticeable abundances of this fish.

  18. Trophic characteristics of a mangrove fish community in Southwest Thailand: Important mangrove contribution and intraspecies feeding variability

    NASA Astrophysics Data System (ADS)

    Zagars, Matiss; Ikejima, Kou; Kasai, Akihide; Arai, Nobuaki; Tongnunui, Prasert

    2013-03-01

    Mangrove production has been found to make a major contribution to the nutrition of a fish community in the Sikao Creek mangrove estuary, Southwest Thailand. Gut content analysis and carbon and nitrogen stable isotope analysis were used to assess fish feeding behavior and trophic reliance on different primary producers (mangrove leaves, phytoplankton, microphytobenthos) focusing on 19 dominant fish species, and 4 potential fish food items. Cluster analysis identified 5 trophic groups and the IsoSource model indicated the importance of primary food sources in trophically supporting different fish species. Most analyzed fish species had carbon isotopic signatures that were more depleted than those reported in previous studies, and the IsoSource model indicated that mangrove leaves were an important primary food source. This may be a specific characteristic of our study site, which is not well connected to other productive coastal habitats that provide alternative primary food sources. Thus we suggest that food chains in trophically isolated mangrove estuaries of southwest Thailand are more dependent on mangrove tree production. We also assessed the relationship of individuality in fish feeding habits and variability of δ13C values and showed that several mangrove fish species have significant intraspecies variability in feeding habits, possibly due to high intraspecific competition.

  19. Waste feed from coastal fish farms: A trophic subsidy with compositional side-effects for wild gadoids

    NASA Astrophysics Data System (ADS)

    Fernandez-Jover, Damian; Martinez-Rubio, Laura; Sanchez-Jerez, Pablo; Bayle-Sempere, Just T.; Lopez Jimenez, Jose Angel; Martínez Lopez, Francisco Javier; Bjørn, Pål-Arne; Uglem, Ingebrigt; Dempster, Tim

    2011-03-01

    Aquaculture of carnivorous fish species in sea-cages typically uses artificial feeds, with a proportion of these feeds lost to the surrounding environment. This lost resource may provide a trophic subsidy to wild fish in the vicinity of fish farms, yet the physiological consequences of the consumption of waste feed by wild fish remain unclear. In two regions in Norway with intensive aquaculture, we tested whether wild saithe ( Pollachius virens) and Atlantic cod ( Gadus morhua) associated with fish farms (F assoc), where waste feed is readily available, had modified diets, condition and fatty acid (FA) compositions in their muscle and liver tissues compared to fish unassociated (UA) with farms. Stomach content analyses revealed that both cod and saithe consumed waste feed in the vicinity of farms (6-96% of their diet was composed of food pellets). This translated into elevated body and liver condition compared to fish caught distant from farms for cod at both locations and elevated body condition for saithe at one of the locations. As a consequence of a modified diet, we detected significantly increased concentrations of terrestrial-derived fatty acids (FAs) such as linoleic (18:2ω6) and oleic (18:1ω9) acids and decreased concentrations of DHA (22:6ω3) in the muscle and/or liver of F assoc cod and saithe when compared with UA fish. In addition, the ω3:ω6 ratio clearly differed between F assoc and UA fish. Linear discriminant analysis (LDA) correctly classified 97% of fish into F assoc or UA origin for both cod and saithe based on the FA composition of liver tissues, and 89% of cod and 86% of saithe into F assoc or UA origin based on the FA composition of muscle. Thus, LDA appears a useful tool for detecting the influence of fish farms on the FA composition of wild fish. Ready availability of waste feed with high protein and fat content provides a clear trophic subsidy to wild fish in coastal waters, yet whether the accompanying side-effect of altered fatty

  20. Feeding ecology of pelagic fish larvae and juveniles in slope waters of the Gulf of Mexico.

    PubMed

    Wells, R J D; Rooker, J R

    2009-11-01

    Stable isotope ratios of carbon (delta13C) and nitrogen (delta15N) were used to investigate feeding patterns of larval and early juvenile pelagic fishes in slope waters of the Gulf of Mexico. Contribution of organic matter supplied to fishes and trophic position within this pelagic food web was estimated in 2007 and 2008 by comparing dietary signatures of the two main producers in this ecosystem: phytoplankton [based on particulate organic matter (POM)] and Sargassum spp. Stable isotope ratios of POM and pelagic Sargassum spp. were significantly different from one another with delta13C values of POM depleted by 3-6 per thousand and delta15N values enriched by 2 relative to Sargassum spp. Stable isotope ratios were significantly different among the five pelagic fishes examined: blue marlin Makaira nigricans, dolphinfish Coryphaena hippurus, pompano dolphinfish Coryphaena equiselis, sailfish Istiophorus platypterus and swordfish Xiphias gladius. Mean delta13C values ranged almost 2 among fishes and were most depleted in I. platypterus. In addition, mean delta15N values ranged 4-5 with highest mean values found for both C. hippurus and C. equiselis and the lowest mean value for M. nigricans during both years. Increasing delta13C or delta15N with standard length suggested that shifts in trophic position and diet occurred during early life for several species examined. Results of a two-source mixing model suggest approximately an equal contribution of organic matter by both sources (POM=55%; pelagic Sargassum spp.=45%) to the early life stages of pelagic fishes examined. Contribution of organic matter, however, varied among species, and sensitivity analyses indicated that organic source estimates changed from 2 to 13% for a delta(13)C fractionation change of +/-0.25 per thousand or a delta15N fractionation change of +/-1.0 per thousand relative to original fractionation values.

  1. Feeding ecology of pelagic fish larvae and juveniles in slope waters of the Gulf of Mexico.

    PubMed

    Wells, R J D; Rooker, J R

    2009-11-01

    Stable isotope ratios of carbon (delta13C) and nitrogen (delta15N) were used to investigate feeding patterns of larval and early juvenile pelagic fishes in slope waters of the Gulf of Mexico. Contribution of organic matter supplied to fishes and trophic position within this pelagic food web was estimated in 2007 and 2008 by comparing dietary signatures of the two main producers in this ecosystem: phytoplankton [based on particulate organic matter (POM)] and Sargassum spp. Stable isotope ratios of POM and pelagic Sargassum spp. were significantly different from one another with delta13C values of POM depleted by 3-6 per thousand and delta15N values enriched by 2 relative to Sargassum spp. Stable isotope ratios were significantly different among the five pelagic fishes examined: blue marlin Makaira nigricans, dolphinfish Coryphaena hippurus, pompano dolphinfish Coryphaena equiselis, sailfish Istiophorus platypterus and swordfish Xiphias gladius. Mean delta13C values ranged almost 2 among fishes and were most depleted in I. platypterus. In addition, mean delta15N values ranged 4-5 with highest mean values found for both C. hippurus and C. equiselis and the lowest mean value for M. nigricans during both years. Increasing delta13C or delta15N with standard length suggested that shifts in trophic position and diet occurred during early life for several species examined. Results of a two-source mixing model suggest approximately an equal contribution of organic matter by both sources (POM=55%; pelagic Sargassum spp.=45%) to the early life stages of pelagic fishes examined. Contribution of organic matter, however, varied among species, and sensitivity analyses indicated that organic source estimates changed from 2 to 13% for a delta(13)C fractionation change of +/-0.25 per thousand or a delta15N fractionation change of +/-1.0 per thousand relative to original fractionation values. PMID:20738644

  2. Retrospective quantification of estuarine feeding activity by coastally caught marine fishes

    NASA Astrophysics Data System (ADS)

    Leakey, Chris D. B.; Attrill, Martin J.; Jennings, Simon; Fitzsimons, Mark F.

    2008-10-01

    Many commercially important marine fishes are found in estuaries, particularly as juveniles. The estuaries may provide a thermal resource, refuge from predators and a source of abundant prey. Here, carbon ( δ13C) and sulphur ( δ34S) stable isotope data from coastally caught common sole ( Solea solea) and whiting ( Merlangius merlangus) were used in independent mixing models to determine relative contributions of estuarine prey to white muscle composition. The influence of assumed trophic fractionation was also investigated with sensitivity analysis. At the population level, there was evidence for estuarine contributions to muscle tissue in both species (means from 16.37% to 61.28%), though among-individual variability was considerable. δ13C and δ34S model outputs implied different estuarine contributions for the same individual, likely reflecting the slower turnover of δ34S than δ13C. Sole exhibited population level plasticity in their feeding as juveniles, separating into two distinct juvenile sub-populations; but they are less plastic as older fish when they adopt increasingly marine diets. Whiting show individual plasticity as both juveniles and adults, feeding on prey of estuarine and coastal origin.

  3. Parallel evolutionary trajectories underlie the origin of giant suspension-feeding whales and bony fishes.

    PubMed

    Friedman, Matt

    2012-03-01

    Giant suspension feeders such as mysticete whales, basking and whale sharks, and the extinct (indicated by '†') †pachycormiform teleosts are conspicuous members of modern and fossil marine vertebrate faunas. Whether convergent anatomical features common to these clades arose along similar evolutionary pathways has remained unclear because of a lack of information surrounding the origins of all groups of large-bodied suspension feeders apart from baleen whales. New investigation reveals that the enigmatic ray-finned fish †Ohmdenia, from the Lower Jurassic (Toarcian, 183.0-175.6 Ma) Posidonia Shale Lagerstätte, represents the immediate sister group of edentulous †pachycormiforms, the longest lived radiation of large vertebrate suspension feeders. †Ohmdenia bisects the long morphological branch leading to suspension-feeding †pachycormiforms, providing information on the sequence of anatomical transformations preceding this major ecological shift that can be compared to changes associated with the origin of modern mysticetes. Similarities include initial modifications to jaw geometry associated with the reduction of dentition, followed by the loss of teeth. The evolution of largest body sizes within both radiations occurs only after the apparent onset of microphagy. Comparing the fit of contrasting evolutionary models to functionally relevant morphological measurements for whales and †pachycormiform fishes reveals strong support for a common adaptive peak shared by suspension-feeding members of both clades.

  4. Parallel evolutionary trajectories underlie the origin of giant suspension-feeding whales and bony fishes

    PubMed Central

    Friedman, Matt

    2012-01-01

    Giant suspension feeders such as mysticete whales, basking and whale sharks, and the extinct (indicated by ‘†’) †pachycormiform teleosts are conspicuous members of modern and fossil marine vertebrate faunas. Whether convergent anatomical features common to these clades arose along similar evolutionary pathways has remained unclear because of a lack of information surrounding the origins of all groups of large-bodied suspension feeders apart from baleen whales. New investigation reveals that the enigmatic ray-finned fish †Ohmdenia, from the Lower Jurassic (Toarcian, 183.0–175.6 Ma) Posidonia Shale Lagerstätte, represents the immediate sister group of edentulous †pachycormiforms, the longest lived radiation of large vertebrate suspension feeders. †Ohmdenia bisects the long morphological branch leading to suspension-feeding †pachycormiforms, providing information on the sequence of anatomical transformations preceding this major ecological shift that can be compared to changes associated with the origin of modern mysticetes. Similarities include initial modifications to jaw geometry associated with the reduction of dentition, followed by the loss of teeth. The evolution of largest body sizes within both radiations occurs only after the apparent onset of microphagy. Comparing the fit of contrasting evolutionary models to functionally relevant morphological measurements for whales and †pachycormiform fishes reveals strong support for a common adaptive peak shared by suspension-feeding members of both clades. PMID:21849314

  5. Mercury Exposure in Healthy Korean Weaning-Age Infants: Association with Growth, Feeding and Fish Intake

    PubMed Central

    Chang, Ju Young; Park, Jeong Su; Shin, Sue; Yang, Hye Ran; Moon, Jin Soo; Ko, Jae Sung

    2015-01-01

    Low-level mercury (Hg) exposure in infancy might be harmful to the physical growth as well as neurodevelopment of children. The aim of this study was to investigate postnatal Hg exposure and its relationship with anthropometry and dietary factors in late infancy. We recruited 252 healthy Korean infants between six and 24 months of age from an outpatient clinic during the 2009/2010 and 2013/2014 seasons. We measured the weight and height of the infants and collected dietary information using questionnaires. The Hg content of the hair and blood was assessed using inductively coupled plasma mass spectroscopy. The geometric mean Hg concentration in the hair and blood was 0.22 (95% confidence interval: 0.20–0.24) µg/g and 0.94 (n = 109, 95% confidence interval: 0.89–0.99) µg/L, respectively. The hair Hg concentration showed a good correlation with the blood Hg concentration (median hair-to-blood Hg ratio: 202.7, r = 0.462, p < 0.001) and was >1 µg/g in five infants. The hair Hg concentration showed significant correlations with weight gain after birth (Z-score of the weight for age—Z-score of the birthweight; r = −0.156, p = 0.015), the duration (months) of breastfeeding as the dominant method of feeding (r = 0.274, p < 0.001), and the duration of fish intake more than once per week (r = 0.138, p = 0.033). In an ordinal logistic regression analysis with categorical hair Hg content (quartiles), dietary factors, including breastfeeding as the dominant method of feeding in late infancy (cumulative odds ratio: 6.235, 95% confidence interval: 3.086–12.597, p < 0.001) and the monthly duration of fish intake more than once per week (cumulative odds ratio: 1.203, 95% confidence interval: 1.034–1.401; p = 0.017), were significantly associated with higher hair Hg content. Weight gain after birth was not, however, significantly associated with hair Hg content after adjustment for the duration of breastfeeding as the dominant method of feeding. Low-level Hg exposure

  6. Mercury Exposure in Healthy Korean Weaning-Age Infants: Association with Growth, Feeding and Fish Intake.

    PubMed

    Chang, Ju Young; Park, Jeong Su; Shin, Sue; Yang, Hye Ran; Moon, Jin Soo; Ko, Jae Sung

    2015-11-01

    Low-level mercury (Hg) exposure in infancy might be harmful to the physical growth as well as neurodevelopment of children. The aim of this study was to investigate postnatal Hg exposure and its relationship with anthropometry and dietary factors in late infancy. We recruited 252 healthy Korean infants between six and 24 months of age from an outpatient clinic during the 2009/2010 and 2013/2014 seasons. We measured the weight and height of the infants and collected dietary information using questionnaires. The Hg content of the hair and blood was assessed using inductively coupled plasma mass spectroscopy. The geometric mean Hg concentration in the hair and blood was 0.22 (95% confidence interval: 0.20-0.24) µg/g and 0.94 (n = 109, 95% confidence interval: 0.89-0.99) µg/L, respectively. The hair Hg concentration showed a good correlation with the blood Hg concentration (median hair-to-blood Hg ratio: 202.7, r = 0.462, p < 0.001) and was >1 µg/g in five infants. The hair Hg concentration showed significant correlations with weight gain after birth (Z-score of the weight for age-Z-score of the birthweight; r = -0.156, p = 0.015), the duration (months) of breastfeeding as the dominant method of feeding (r = 0.274, p < 0.001), and the duration of fish intake more than once per week (r = 0.138, p = 0.033). In an ordinal logistic regression analysis with categorical hair Hg content (quartiles), dietary factors, including breastfeeding as the dominant method of feeding in late infancy (cumulative odds ratio: 6.235, 95% confidence interval: 3.086-12.597, p < 0.001) and the monthly duration of fish intake more than once per week (cumulative odds ratio: 1.203, 95% confidence interval: 1.034-1.401; p = 0.017), were significantly associated with higher hair Hg content. Weight gain after birth was not, however, significantly associated with hair Hg content after adjustment for the duration of breastfeeding as the dominant method of feeding. Low-level Hg exposure through

  7. Fluid dynamics of feeding behaviour in white-spotted bamboo sharks.

    PubMed

    Nauwelaerts, Sandra; Wilga, Cheryl D; Lauder, George V; Sanford, Christopher P

    2008-10-01

    Although the motor control of feeding is presumed to be generally conserved, some fishes are capable of modulating the feeding behaviour in response to prey type and or prey size. This led to the 'feeding modulation hypothesis', which states that rapid suction strikes are pre-programmed stereotyped events that proceed to completion once initiated regardless of sensory input. If this hypothesis holds true, successful strikes should be indistinguishable from unsuccessful strikes owing to a lack of feedback control in specialized suction feeding fishes. The hydrodynamics of suction feeding in white-spotted bamboo sharks (Chiloscyllium plagiosum) was studied in three behaviours: successful strikes, intraoral transports of prey and unsuccessful strikes. The area of the fluid velocity region around the head of feeding sharks was quantified using time-resolved digital particle image velocimetry (DPIV). The maximal size of the fluid velocity region is 56% larger in successful strikes than unsuccessful strikes (10.79 cm2 vs 6.90 cm2), but they do not differ in duration, indicating that strikes are modulated based on some aspect of the prey or simply as a result of decreased effort on the part of the predator. The hydrodynamic profiles of successful and unsuccessful strikes differ after 21 ms, a period probably too short to provide time to react through feedback control. The predator-to-prey distance is larger in missed strikes compared with successful strikes, indicating that insufficient suction is generated to compensate for the increased distance. An accuracy index distinguishes unsuccessful strikes (-0.26) from successful strikes (0.45 to 0.61). Successful strikes occur primarily between the horizontal axis of the mouth and the dorsal boundary of the ingested parcel of water, and missed prey are closer to the boundary or beyond. Suction transports are shorter in duration than suction strikes but have similar maximal fluid velocity areas to move the prey through the

  8. Investigation of the available technologies and their feasibility for the conversion of food waste into fish feed in Hong Kong.

    PubMed

    Cheng, Jack Y K; Lo, Irene M C

    2016-04-01

    Food waste is the largest constituent of municipal solid waste in Hong Kong, but food waste recycling is still in its infancy. With the imminent saturation of all landfill sites by 2020, multiple technologies are needed to boost up the food waste recycling rate in Hong Kong. Conversion of food waste into animal feeds is prevalent in Japan, South Korea, and Taiwan, treating over 40 % of their recycled food waste. This direction is worth exploring in Hong Kong once concerns over food safety are resolved. Fortunately, while feeding food waste to pigs and chickens poses threats to public health, feeding it to fish is considered low risk. In order to examine the feasibility of converting food waste into fish feed in Hong Kong, this paper investigates the market demand, technical viability, feed quality, regulatory hurdles, and potential contribution. The results show that a significant amount of food waste can be recycled by converting it into fish feed due to the enormous demand from feed factories in mainland China. Two conversion technologies, heat drying and black soldier fly bioconversion, are studied extensively. Black soldier fly bioconversion is preferable because the end-product, insect powder, is anticipated to gain import approval from mainland China. The authors suggest further research efforts to speed up its application for food waste recycling in urban cities.

  9. Effects of feeding fermented fish on egg cholesterol content in hens.

    PubMed

    Loh, Teck-Chwen; Law, Fang-Ling; Goh, Yong-Meng; Foo, Hooi-Ling; Zulkifli, Idrus

    2009-02-01

    This study was conducted to investigate the effects of feeding fermented fish (FF) to layers on laying performance, and polyunsaturated fatty acid and cholesterol levels in eggs and plasma. A total of 96, 13-week-old Babcock B380 pullets were used in this study. They were randomly assigned to four numerically equal groups with eight replicates per treatment, three birds per replicate. All the birds were housed in individual cages. The dietary treatments were: Control diet, without FF; FF3 diet containing 3% (w/w) FF, FF6 diet containing 6% (w/w) FF and FF9 diet containing 9% (w/w) FF. The study was carried out for 16 weeks inclusive of two weeks of adjustment. Weekly feed intake and egg production were recorded. Blood plasma cholesterol and fatty acid profiles were assayed at the end of the experiment. FF did not enhance (P > 0.05) egg mass but (P < 0.05) decreased egg weight slightly. However, egg yolk cholesterol and plasma cholesterol concentrations were reduced (P < 0.05) by FF. The n-6:n-3 fatty acids ratio in the egg yolk (Control = 7.9, FF9 = 6.2) and plasma (Control = 10.6, FF9 = 6.2) were decreased by feeding FF. Moreover, FF was able to increase (P < 0.05) the docosahexaenoic acid (DHA) concentrations in egg yolk and plasma. In conclusion, this study demonstrated that FF increased DHA and reduced egg yolk cholesterol in poultry eggs. PMID:20163464

  10. Piscivorous fish exhibit temperature-influenced binge feeding during an annual prey pulse

    USGS Publications Warehouse

    Furey, Nathan B.; Hinch, Scott G.; Mesa, Matthew G.; Beauchamp, David A.

    2016-01-01

    Understanding the limits of consumption is important for determining trophic influences on ecosystems and predator adaptations to inconsistent prey availability. Fishes have been observed to consume beyond what is sustainable (i.e. digested on a daily basis), but this phenomenon of hyperphagia (or binge-feeding) is largely overlooked. We expect hyperphagia to be a short-term (1-day) event that is facilitated by gut volume providing capacity to store consumed food during periods of high prey availability to be later digested.We define how temperature, body size and food availability influence the degree of binge-feeding by comparing field observations with laboratory experiments of bull trout (Salvelinus confluentus), a large freshwater piscivore that experiences highly variable prey pulses. We also simulated bull trout consumption and growth during salmon smolt outmigrations under two scenarios: 1) daily consumption being dependent upon bioenergetically sustainable rates and 2) daily consumption being dependent upon available gut volume (i.e. consumption is equal to gut volume when empty and otherwise ‘topping off’ based on sustainable digestion rates).One-day consumption by laboratory-held bull trout during the first day of feeding experiments after fasting exceeded bioenergetically sustainable rates by 12- to 87-fold at low temperatures (3 °C) and by  ˜1·3-fold at 20 °C. The degree of binge-feeding by bull trout in the field was slightly reduced but largely in agreement with laboratory estimates, especially when prey availability was extremely high [during a sockeye salmon (Oncorhynchus nerka) smolt outmigration and at a counting fence where smolts are funnelled into high densities]. Consumption by bull trout at other settings were lower and more variable, but still regularly hyperphagic.Simulations demonstrated the ability to binge-feed increased cumulative consumption (16–32%) and cumulative growth (19–110%) relative to only feeding at

  11. Piscivorous fish exhibit temperature-influenced binge feeding during an annual prey pulse.

    PubMed

    Furey, Nathan B; Hinch, Scott G; Mesa, Matthew G; Beauchamp, David A

    2016-09-01

    Understanding the limits of consumption is important for determining trophic influences on ecosystems and predator adaptations to inconsistent prey availability. Fishes have been observed to consume beyond what is sustainable (i.e. digested on a daily basis), but this phenomenon of hyperphagia (or binge-feeding) is largely overlooked. We expect hyperphagia to be a short-term (1-day) event that is facilitated by gut volume providing capacity to store consumed food during periods of high prey availability to be later digested. We define how temperature, body size and food availability influence the degree of binge-feeding by comparing field observations with laboratory experiments of bull trout (Salvelinus confluentus), a large freshwater piscivore that experiences highly variable prey pulses. We also simulated bull trout consumption and growth during salmon smolt outmigrations under two scenarios: 1) daily consumption being dependent upon bioenergetically sustainable rates and 2) daily consumption being dependent upon available gut volume (i.e. consumption is equal to gut volume when empty and otherwise 'topping off' based on sustainable digestion rates). One-day consumption by laboratory-held bull trout during the first day of feeding experiments after fasting exceeded bioenergetically sustainable rates by 12- to 87-fold at low temperatures (3 °C) and by  ˜1·3-fold at 20 °C. The degree of binge-feeding by bull trout in the field was slightly reduced but largely in agreement with laboratory estimates, especially when prey availability was extremely high [during a sockeye salmon (Oncorhynchus nerka) smolt outmigration and at a counting fence where smolts are funnelled into high densities]. Consumption by bull trout at other settings were lower and more variable, but still regularly hyperphagic. Simulations demonstrated the ability to binge-feed increased cumulative consumption (16-32%) and cumulative growth (19-110%) relative to only feeding at

  12. Potential changes in feeding behavior of Antarctic fish, Pseudotrematomus bernacchii (Boulenger, 1902) on the East Ongul Island, Antarctica

    NASA Astrophysics Data System (ADS)

    Chavanich, Suchana; Viyakarn, Voranop; Nomura, Daiki; Watanabe, Kentaro

    2015-12-01

    The feeding habits of the Antarctic fish Pseudotrematomus bernacchii (Previous name: Trematomus bernacchii) under the fast ice around Japanese Syowa Station were investigated in the summers of 2004/2005 and 2009/2010. The results showed that amphipods and krill were the major prey. However, there was a significant difference in the proportions of larger invertebrates such as squids, octopus and other crustaceans found in the fish stomachs between 2009/2010 and the previous years. Moreover, the percentage of amphipods and krill in fish stomachs declined over the 5-year period in all fish size classes. Several factors including sea ice melting, habitat and environmental changes might have influenced the pattern of feeding behavior.

  13. Culture of harpacticoid copepods: potential as live feed for rearing marine fish.

    PubMed

    Cutts, Christopher J

    2003-01-01

    Copepods are useful as food for marine fish cultivation, in terms of both nutrition and ease of culture. Harpacticoid copepods are favoured over calanoids, since harpacticoids, as a result of their benthic habitat, can be reared at much higher densities. However, their benthic nature also makes mass culture difficult, since large surface areas must be provided. Within Harpacticoida, Tisbe spp. seem most useful, having high overall fecundity, and positive phototaxis of the nauplii. Harpacticoids can synthesise de novo several nutritionally important essential fatty acids (EFA), making them desirable as food for rearing marine fish. However, a diet rich in EFAs (e.g. animal derived feed) improves the productivity of copepod cultures, suggesting that the synthesis of EFA is rate-limiting for their reproduction. The nature of the substratum is also important in maintaining a good population, since harpacticoid biomass is more dependent on surface area than volume of a culture. Heterogeneous substrates can support large cultures because of their high surface area, but efficient cleaning methods are necessary. Frequent harvesting of populations will maintain good water quality and an overall low density of sexually mature copepods, raising naupliar productivity overall. Over-harvesting will naturally deplete the population. Harpacticoids are generally tolerant of environmental fluctuations but they do have temperature and salinity optima, and these will be species- and strain-dependent. Harpacticoid copepods are better food for fish larvae than Artemia, because of their ability to synthesise EFAs. The nauplii of harpacticoids are energetically poor but appear to have an appetite-stimulatory effect. Uneaten nauplii grow within the fish rearing tanks and graze on the walls, building up their own nutritional value and maintaining tank hygiene.

  14. Feeding ecology of indigenous and non-indigenous fish species within the family Sphyraenidae.

    PubMed

    Kalogirou, S; Mittermayer, F; Pihl, L; Wennhage, H

    2012-06-01

    The feeding ecology of two common indigenous (Sphyraena viridensis and Sphyraena sphyraena) and one abundant non-indigenous sphyraenid species, Sphyraena chrysotaenia, of Indo-Pacific Ocean origin, was investigated in an area of the eastern Mediterranean Sea. The stomach contents of 738 individuals of varying size, collected during the period December 2008 to August 2009, were examined. The dietary analyses revealed that all three species were specialized piscivores with a diet consisting of >90% fish, both by number and mass. Concurrent sampling of the fish assemblage made it possible to calculate selectivity as well as diet breadth and overlap of these strict piscivores. Even though several prey species were found in the stomachs of the three predators examined, selectivity towards Atherina boyeri was highly significant. For all species examined, >70% of the diet by mass was made up by three indigenous species of commercial value: Spicara smaris, Boops boops and A. boyeri. Diet breadth and size of prey increased with increasing body size for all predators. With increased body size, the diet overlap between indigenous and non-indigenous species decreased. This could be attributed to increased diet breadth and the specific life-history characteristics of indigenous species developing into larger individuals. During winter, the condition factor of the non-indigenous species was significantly lower than that of the indigenous, indicating that winter conditions in the Mediterranean Sea may limit its further expansion north and westward. With this study, the gap in knowledge of the feeding preferences of the most abundant piscivorous species found in coastal areas of the study region is filled. Additionally, the results indicate that non-indigenous species familial affiliation to indigenous ones does not facilitate invasion success. PMID:22650432

  15. Feeding habits of an endemic fish, Oxygymnocypris stewartii, in the Yarlung Zangbo River in Tibet, China

    USGS Publications Warehouse

    Huo, Bin; Xie, Cong Xin; Madenjian, Charles P.; Ma, Bao Shan; Yang, Xue Feng; Huang, Hai Ping

    2014-01-01

    Feeding habits of Oxygymnocypris stewartii were investigated based on monthly sampling in the Yarlung Zangbo River from August 2008 to August 2009. The gut contents of 194 individuals were analysed and quantified with numerical and gravimetric methods. This species can be considered a generalized and opportunistic predator feeding both on teleosts and aquatic insects. A multivariate analysis revealed noticeable variation in O. stewartii diet composition with fish size and season. The smaller specimens fed primarily on Cobitidae and Hydropsychidae. As they grew, Cyprinidae and Chironomidae larvae became important prey. The preferred food items were teleosts in summer and autumn. For winter and spring, the predominant prey switched to chironomidae larvae. Diet composition did not significantly vary between the sexes. Finally, a significant and positive correlation between predator and prey length was found. These findings provide the fundamental information better understanding the role of this important endemic species in the Yarlung Zangbo River food web.

  16. Intraoral transmental suction lipectomy.

    PubMed

    Mommaerts, M Y; Abeloos, J V S; De Clerq, C A S; Neyt, L F

    2002-08-01

    Intraoral transmental suction lipectomy (TMSL) is performed by entering the suction canula through the chin osteotomy/ostectomy gap into the sub- and/or supraplatysmal fat tissue layers. The aim of the study was to know patients' and operators' satisfaction with the procedure, and to know the kind and frequency of the complications. Twenty patients were consecutively treated and reviewed after a minimum of 5 years. All were satisfied with the overall results. It proved difficult to differentiate between the results of the liposuction and those of the genioplasty and/or orthognathic profile correction. From a surgeon's point of view, 11 showed excellent, nine good and one moderate results. Complications included one local subcutaneous infection, four transient neurosensory disturbances at the lower lip and two marginal branch weaknesses. All complications were resolved by the time of the long-term follow-up appointment. TMSL offers the psychological advantage of being performed without skin incision. Cosmetic results and complications are similar to those obtained with the transcutaneous liposuction techniques. PMID:12361067

  17. Diet and feeding of fish from Grande River, located below the Volta Grande Reservoir, MG-SP.

    PubMed

    Andrade, P M; Braga, F M S

    2005-08-01

    We compare the classic model of feeding of tropical fish by means of six bimonthly samplings using gillnets of varying mesh sizes that were inspected every twelve hours throughout a forty-eight hour period. The stomachs of the fish caught were classified in three categories according to quantity of food found. The amount of fat in the visceral cavity with respect to the energetic reserve deposition was also studied. The relative frequencies of the different categories of stomach repletion and fat deposition were examined for patterns of feeding seasonality. The stomachs considered full were examined to record diet composition. To assess the relative importance of the different food resources, we applied Feeding Importance Degree (FID), which is a useful index when difficulties exist in determining a common basis for volume, number, or weight of a given food item in different species, a common problem when dealing with fish species having different feeding habits. The fish species whose stomach contents were analyzed using the FID index were Serrasalmus spilopleura (Characidae), L. prolixa (Loricaridae), Schizodon nasutus (Anostomidae), and Pimelodus maculatus (Pimelodidae). Our findings indicate some contrasting elements, in dietary composition in relation to the classic model for tropical rivers. These factors include the importance of aquatic macrophytes, the lack of piscivorous species, and a lesser presence of allochthonous vegetation in the diet of the species studied. PMID:16341415

  18. Diet and feeding of fish from Grande River, located below the Volta Grande Reservoir, MG-SP.

    PubMed

    Andrade, P M; Braga, F M S

    2005-08-01

    We compare the classic model of feeding of tropical fish by means of six bimonthly samplings using gillnets of varying mesh sizes that were inspected every twelve hours throughout a forty-eight hour period. The stomachs of the fish caught were classified in three categories according to quantity of food found. The amount of fat in the visceral cavity with respect to the energetic reserve deposition was also studied. The relative frequencies of the different categories of stomach repletion and fat deposition were examined for patterns of feeding seasonality. The stomachs considered full were examined to record diet composition. To assess the relative importance of the different food resources, we applied Feeding Importance Degree (FID), which is a useful index when difficulties exist in determining a common basis for volume, number, or weight of a given food item in different species, a common problem when dealing with fish species having different feeding habits. The fish species whose stomach contents were analyzed using the FID index were Serrasalmus spilopleura (Characidae), L. prolixa (Loricaridae), Schizodon nasutus (Anostomidae), and Pimelodus maculatus (Pimelodidae). Our findings indicate some contrasting elements, in dietary composition in relation to the classic model for tropical rivers. These factors include the importance of aquatic macrophytes, the lack of piscivorous species, and a lesser presence of allochthonous vegetation in the diet of the species studied.

  19. Selective feeding by coral reef fishes on coral lesions associated with brown band and black band disease

    NASA Astrophysics Data System (ADS)

    Chong-Seng, K. M.; Cole, A. J.; Pratchett, M. S.; Willis, B. L.

    2011-06-01

    Recent studies have suggested that corallivorous fishes may be vectors for coral disease, but the extent to which fishes actually feed on and thereby potentially transmit coral pathogens is largely unknown. For this study, in situ video observations were used to assess the level to which fishes fed on diseased coral tissues at Lizard Island, northern Great Barrier Reef. Surveys conducted at multiple locations around Lizard Island revealed that coral disease prevalence, especially of brown band disease (BrB), was higher in lagoon and backreef locations than in exposed reef crests. Accordingly, video cameras were deployed in lagoon and backreef habitats to record feeding by fishes during 1-h periods on diseased sections of each of 44 different coral colonies. Twenty-five species from five fish families (Blennidae, Chaetodontidae, Gobiidae, Labridae and Pomacentridae) were observed to feed on infected coral tissues of staghorn species of Acropora that were naturally infected with black band disease (BBD) or brown band disease (BrB). Collectively, these fishes took an average of 18.6 (±5.6 SE) and 14.3 (±6.1 SE) bites per hour from BBD and BrB lesions, respectively. More than 40% (408/948 bites) and nearly 25% (314/1319 bites) of bites were observed on lesions associated with BBD and BrB, respectively, despite these bands each representing only about 1% of the substratum available. Moreover, many corallivorous fishes ( Labrichthys unilineatus, Chaetodon aureofasciatus, C. baronessa, C. lunulatus, C. trifascialis, Cheiloprion labiatus) selectively targeted disease lesions over adjacent healthy coral tissues. These findings highlight the important role that reef fishes may play in the dynamics of coral diseases, either as vectors for the spread of coral disease or in reducing coral disease progression through intensive and selective consumption of diseased coral tissues.

  20. Decontamination trends in the aquacultured fish gilthead seabream (Sparus aurata) after feeding long-term a PCDD/F spiked feed.

    PubMed

    Abalos, Manuela; Parera, Jordi; Estévez, Alicia; Solé, Montserrat; Fabregat, Mari Carmen; Piña, Benjamin; Navarro, Anna; Abad, Esteban

    2011-01-01

    Aquacultured fish gilthead seabream (Sparusaurata), previously exposed to low levels of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) trough the diet for a 13 months period, were fed on a clean feed for another 22 months. Gilthead seabream is a protandrous hermaphrodite species and this "decontamination" period coincided with the stages of sex differentiation, maturity and reproduction of the fish. PCDD/F levels in the fish tissues (i.e. muscle, liver, perivisceral fat and gonads), expressed in pg WHO-TEQg⁻¹ fresh weight, showed a general decreasing trend during the "decontamination" period. However, this general trend varied among tissues and was also dependent on sex and lipid contents. Toxicological effects affecting fish behaviour and hepatic marker responses were also evaluated. The results pointed out that exposure to PCDD/Fs did not have an impact on fish development and reproduction, since the proportion of sexes found after the sex reversal process was within the normal range described for this species. In addition, long-term exposure to low PCDD/F levels did not significantly affect the response of most of the biochemical markers considered. On the contrary, some of them (e.g. EROD activity) showed variations in their responses during the sex differentiation process and onwards. Finally, the hepatic AhR mRNA levels increased during dioxin exposure but they returned to values typical for non-exposed fish after the "decontamination" period.

  1. Oryzias melastigma - an effective substitute for exotic larvicidal fishes: enhancement of its reproductive potential by supplementary feeding.

    PubMed

    Dutta, Abir Lal; Dey, Sajal Kumar; Chakraborty, Debargha; Manna, Asim Kumar; Manna, Pankaj Kumar

    2013-12-01

    A preliminary study was conducted on the efficacy of Oryzias melastigma in consuming mosquito larva so as to control mosquito and mosquito borne diseases, and enhancing its reproductive success using supplementary feed. Oryzias melastigma is a larvivore fish and widely distributed in the shallow water, wetlands of Gangetic plains and peninsular India. These studies indicate that O. melastigma is a prolific breeder and gregarious feeder of mosquito larvae. Increased reproduction by providing different supplementary feed, of which Ulothrix acted remarkably, may aid in wide spread use of this fish as a biological control measure against mosquitoes. One adult fish of any sex can consume 87.1% first instars mosquito larvae/day. So, early stages of mosquito larvae are effectively controlled, as compared to other successive stages. Ulothrix has considerable effect on egg production, successful hatching and regaining reproductive maturity of female in surprisingly quicker interval. PMID:23807913

  2. Quantification of malachite green in fish feed utilising liquid chromatography-tandem mass spectrometry with a monolithic column.

    PubMed

    Abro, Kamran; Mahesar, Sarfaraz Ahmed; Iqbal, Seema; Perveen, Shahnaz

    2014-01-01

    The purpose of this study was to develop a rapid and sensitive method for the quantification of malachite green (MG) in fish feed using LC-ESI-MS/MS with a monolithic column as stationary phase. Fish feed was cleaned using ultrasonic assisted liquid-liquid extraction. The separation was achieved on a Chromolith® Performance RP-18e column (100 × 4.6 mm) using gradient mobile phase composition of methanol and 0.1% formic acid at the flow rate of 1.0 ml min⁻¹. The analyte was ionised using electrospray ionisation in positive mode. Mass spectral transitions were recorded in selected reaction monitoring (SRM) mode at m/z 329.78 → m/z 314.75 with a collision energy (CE) of 52% for MG. The system suitability responses were calculated for reproducibility tests of the retention time, number of theoretical plates and capacity factor. System validation was evaluated for precision, specificity and linearity of MG. The linearity and calibration graph was plotted in the range of 15.0-250 ng ml⁻¹ with the regression coefficient of >0.997. The lower limits of detection and quantification for MG were 0.55 and 1.44 ng ml⁻¹, respectively, allowing easy determination in fish feed with accuracy evaluated as a percentage recovery of 92.1% and precision determined as % CV of < 5. The method was also extended to the determination of MG in an actual fish feed. The sensitivity and selectivity of LC-ESI-MS/MS using monolithic column offers a valuable alternative to the methodologies currently employed for the quantification of MG in fish feeds.

  3. Influence of substrate orientation on feeding kinematics and performance of algae-grazing Lake Malawi cichlid fishes.

    PubMed

    Rupp, Maxwell F; Hulsey, C Darrin

    2014-09-01

    Lake Malawi cichlids have been studied extensively in an effort to elucidate the mechanisms underlying their adaptive radiation. Both habitat partitioning and trophic specialization have been suggested to be critical ecological axes underlying the exceptional diversification of these fishes, but the mechanisms facilitating this divergence are often unclear. For instance, in the rock-dwelling mbuna of Lake Malawi, coexistence is likely tightly linked to how and where species feed on the algae coating all the surfaces of the rocky reefs they exclusively inhabit. Yet, although mbuna species often preferentially graze from particular substrate orientations, we understand very little about how substrate orientation influences feeding kinematics or feeding rates in any group of organisms. Therefore, for three species of mbuna, we quantified feeding kinematics and inferred the rates that algae could be ingested on substrates that mimicked the top, side and bottom of the algae-covered boulders these species utilize in Lake Malawi. A number of differences in feeding kinematics were found among species, and several of the kinematic variables were found to differ even within species when the fish grazed from different surface orientations. However, despite their preferences for particular microhabitats, we found no evidence for clear trade-offs in the rates that the three species were inferred to be able to obtain algae from different substrate orientations. Nevertheless, our results indicate microhabitat divergence linked to differences in feeding kinematics could have played a role in the origin and maintenance of the vast diversity of co-occurring Lake Malawi mbuna species.

  4. The biological role of pituitary adenylate cyclase-activating polypeptide (PACAP) in growth and feeding behavior in juvenile fish.

    PubMed

    Lugo, Juana Maria; Oliva, Aymé; Morales, Antonio; Reyes, Osvaldo; Garay, Hilda Elisa; Herrera, Fidel; Cabrales, Ania; Pérez, Ever; Estrada, Mario Pablo

    2010-11-01

    To date, many technologies have been developed to increase efficiency in aquaculture, but very few successful biotechnology molecules have arrived on the market. In this context, marine biotechnology has an opportunity to develop products to improve the output of fish in aquaculture. Published in vivo studies on the action of the pituitary adenylate cyclase-activating polypeptide (PACAP) in fish are scarce. Recently, our group, for the first time, demonstrated the biological role of this neuropeptide administrated by immersion baths in the growth and development of larval fish. In this work, we have evaluated the effects of recombinant Clarias gariepinus PACAP administration by intraperitoneal injection on growth performance and feeding behavior in juvenile fish. Our results showed the physiological role of this peptide for growth control in fish, including the juvenile stage, and confirm that its biological functions are well conserved in fish, since C. gariepinus PACAP stimulated growth in juvenile tilapia Oreochromis niloticus. In addition, we have observed that the growth-promoting effect of PACAP in juvenile tilapia was correlated with higher GH concentration in serum. With regard to the neuroendocrine regulation of growth control by PACAP, it was demonstrated that PACAP stimulates food intake in juvenile tilapia. In general, PACAP appears to act in the regulation of the growth control in juvenile fish. These findings propose that PACAP is a prominent target with the potential to stimulate fish growth in aquaculture. PMID:20853308

  5. Trace elements in farmed fish (Cyprinus carpio, Ctenopharyngodon idella and Oncorhynchus mykiss) from Beijing: implication from feed.

    PubMed

    Jiang, Haifeng; Qin, Dongli; Mou, Zhenbo; Zhao, Jiwei; Tang, Shizhan; Wu, Song; Gao, Lei

    2016-06-01

    Concentrations of 30 trace elements, Li, V, Cr, Mn, Fe, Ni, Cu, Mo, Zn, Se, Sr, Co, Al, Ti, As, Cs, Sc, Te, Ba, Ga, Pb, Sn, Cd, Sb, Ag, Tm, TI, Be, Hg and U in major cultured freshwater fish species (common carp-Cyprinus carpio, grass carp-Ctenopharyngodon idella and rainbow trout-Oncorhynchus mykiss) with the corresponding feed from 23 fish farms in Beijing, China, were investigated. The results revealed that Fe, Zn, Cu, Mn, Sr, Se were the major accumulated essential elements and Al, Ti were the major accumulated non-essential elements, while Mo, Co, Ga, Sn, Cd, Sb, Ag, Tm, U, TI, Be, Te, Pb and Hg were hardly detectable. Contents of investigated trace elements were close to or much lower than those in fish from other areas in China. Correlation analysis suggested that the elemental concentrations in those fish species were relatively constant and did not vary much with the fish feed. In comparison with the limits for aquafeeds and fish established by Chinese legislation, Cd in 37.5% of rainbow trout feeds and As in 20% of rainbow trout samples exceeded the maximum limit, assuming that inorganic As accounts for 10% of total As. Further health risk assessment showed that fish consumption would not pose risks to consumers as far as non-essential element contaminants are concerned. However, the carcinogenic risk of As in rainbow trout for the inhabitants in Beijing exceeded the acceptable level of 10(-)(4), to which more attention should be paid. PMID:26892032

  6. Replacing fish meal by food waste in feed pellets to culture lower trophic level fish containing acceptable levels of organochlorine pesticides: health risk assessments.

    PubMed

    Cheng, Zhang; Mo, Wing-Yin; Man, Yu-Bon; Nie, Xiang-Ping; Li, Kai-Bing; Wong, Ming-Hung

    2014-12-01

    The present study used food waste (collected from local hotels and restaurants) feed pellets in polyculture of low-trophic level fish [bighead (Aristichtys nobilis), grass carp (Ctenopharyngodon idellus), and mud carp (Cirrhina molitorella)] aiming at producing safe and quality products for local consumption. The results indicated that grass carp (hexachlorocyclohexanes (HCHs) <0.03; dichlorodiphenyltrichloroethanes (DDTs) 1.42-3.34 ng/g ww) and bighead carp (HCHs<0.03; DDTs 1.55-2.56 ng/g ww) fed with food waste feed pellets were relatively free of organochlorine pesticides (OCPs). The experimental ponds (water and sediment) were relatively free of OCPs, lowering the possibility of biomagnification of OCPs in the food chains within the ponds. The raw concentrations of OCPs extracted from the fish were not in the bioavailable form, which would ultimately reach bloodstream and exert adverse effects on human body. Health risk assessments based on digestible concentrations are commonly regarded as a more accurate method. The results of health risk assessments based on raw and digestible concentrations showed that the fish fed with food waste feed pellets were safe for consumption from the OCP perspective.

  7. Replacing fish meal by food waste in feed pellets to culture lower trophic level fish containing acceptable levels of organochlorine pesticides: health risk assessments.

    PubMed

    Cheng, Zhang; Mo, Wing-Yin; Man, Yu-Bon; Nie, Xiang-Ping; Li, Kai-Bing; Wong, Ming-Hung

    2014-12-01

    The present study used food waste (collected from local hotels and restaurants) feed pellets in polyculture of low-trophic level fish [bighead (Aristichtys nobilis), grass carp (Ctenopharyngodon idellus), and mud carp (Cirrhina molitorella)] aiming at producing safe and quality products for local consumption. The results indicated that grass carp (hexachlorocyclohexanes (HCHs) <0.03; dichlorodiphenyltrichloroethanes (DDTs) 1.42-3.34 ng/g ww) and bighead carp (HCHs<0.03; DDTs 1.55-2.56 ng/g ww) fed with food waste feed pellets were relatively free of organochlorine pesticides (OCPs). The experimental ponds (water and sediment) were relatively free of OCPs, lowering the possibility of biomagnification of OCPs in the food chains within the ponds. The raw concentrations of OCPs extracted from the fish were not in the bioavailable form, which would ultimately reach bloodstream and exert adverse effects on human body. Health risk assessments based on digestible concentrations are commonly regarded as a more accurate method. The results of health risk assessments based on raw and digestible concentrations showed that the fish fed with food waste feed pellets were safe for consumption from the OCP perspective. PMID:25080070

  8. Influence of intrinsic signals and environmental cues on the endocrine control of feeding in fish: potential application in aquaculture.

    PubMed

    Volkoff, Hélène; Hoskins, Leah J; Tuziak, Sarah M

    2010-07-01

    Optimization of food consumption and ultimately growth are major concerns for aquaculture. In fish, food intake is regulated by several hormones produced by both brain and peripheral tissues. Changes in feeding behavior and appetite usually occur through the modulation of the gene expression and/or action of these appetite-regulating hormones and can be due not only to variations in intrinsic factors such as nutritional/metabolic or reproductive status, but also to changes in environmental factors, such as temperature and photoperiod. In addition, the gene expression and/or plasma levels of appetite-regulating hormones might also display daily as well as circannual (seasonal) rhythms. Despite recent advances, our current understanding of the regulation of feeding in fish is still limited. We give here a brief overview of our current knowledge of the endocrine regulation of feeding in fish and describe how a better understanding of appetite-related hormones in fish might lead to the development of sustainable aquaculture.

  9. Assessing impacts of land-applied manure from concentrated animal feeding operations on fish populations and communities.

    PubMed

    Leet, Jessica K; Lee, Linda S; Gall, Heather E; Goforth, Reuben R; Sassman, Stephen; Gordon, Denise A; Lazorchak, James M; Smith, Mark E; Jafvert, Chad T; Javfert, Chad T; Sepúlveda, Maria S

    2012-12-18

    Concentrated animal feeding operation (CAFO) manure is a cost-effective fertilizer. In the Midwest, networks of subsurface tile-drains expedite transport of animal hormones and nutrients from land-applied CAFO manure to adjacent waterways. The objective of this study was to evaluate impacts of land-applied CAFO manure on fish populations and communities. Water chemistry including hormone, pesticide, and nutrient concentrations was characterized from study sites along with fish assemblage structure, growth, and endocrine disruption assessed in selected fish species. Although most CAFO water samples had hormone concentrations <1 ng/L, equivalent concentrations for 17β-E2 and 17α-TB peaked at >30 ng/L each during the period of spawning, hatching, and development for resident fishes. CAFO sites had lower fish species richness, and fishes exhibited faster somatic growth and lower reproductive condition compared to individuals from the reference site. Fathead minnows (Pimephales promelas) exposed to CAFO ditchwater during early developmental stages exhibited significantly skewed sex ratios toward males. Maximum observed hormone concentrations were well above the lowest observable effect concentrations for these hormones; however, complexities at the field scale make it difficult to directly relate hormone concentration and impacts on fish. Complicating factors include the consistent presence of pesticides and nutrients, and the difference in temperature and stream architecture of the CAFO-impacted ditches compared to the reference site (e.g., channelization, bottom substrate, shallow pools, and riparian cover). PMID:23171355

  10. [The feeding activity of herbivorous fishes and their impact on coral reefs with different levels of anthropogenic degradation].

    PubMed

    Durán, Alain; Claro, Rodolfo

    2009-09-01

    The feeding activity of three herbivorous fishes (Sparisoma viride, Scarus iserti and Acanthurus coeruleus) and its impact on two coral reefs were studied during the dry (February) and rainy (August) seasons of 2006 in Cuba. One of the reef stations is at the "Acuario" dive point in the Guanahacabibes National Park, and is relatively pristine. The second one is located at the north coast of Havana City facing the Instituto de Oceanología (IdO) and is subject to pollution and fishing pressures. Herbivore fish composition was analized, and foraging intensity was measured for all Acanthurid and Scarid species, by counting fish bites in 1 m2 during five minute intervals (25 replicates). Concurrently, species foraging intensity was measured for juvenile, intermediate, and adult phases, counting fish bites during 10 minutes intervals (10 replicates). Algal consumption rate was estimated using a coefficent of consumed biomass per bite, for each size class. The algal cover was sampled at 20 m linear transects with four replicates at each site. Food items were assessed sampling algae at the observed bitten substrates. Compared to Acuario, herbivores in IdO showed lower species richness and higher density of small size fishes, but large-sized parrotfish was almost absent due to intense fishing. The highest bite rate was observed for the smallest fish size, but net consumption rate was three times greater for medium and great size fishes, which were more abundant in the protected area. Algal cover was lower in Acuario, while in IdO it was very high, and coral cover was very low. In both locations epiphytic algae were the preferred food. These results support generalizations referring to the importance of great size herbivores fishes in controlling excesive algal proliferation on coral reefs. PMID:19928463

  11. [The feeding activity of herbivorous fishes and their impact on coral reefs with different levels of anthropogenic degradation].

    PubMed

    Durán, Alain; Claro, Rodolfo

    2009-09-01

    The feeding activity of three herbivorous fishes (Sparisoma viride, Scarus iserti and Acanthurus coeruleus) and its impact on two coral reefs were studied during the dry (February) and rainy (August) seasons of 2006 in Cuba. One of the reef stations is at the "Acuario" dive point in the Guanahacabibes National Park, and is relatively pristine. The second one is located at the north coast of Havana City facing the Instituto de Oceanología (IdO) and is subject to pollution and fishing pressures. Herbivore fish composition was analized, and foraging intensity was measured for all Acanthurid and Scarid species, by counting fish bites in 1 m2 during five minute intervals (25 replicates). Concurrently, species foraging intensity was measured for juvenile, intermediate, and adult phases, counting fish bites during 10 minutes intervals (10 replicates). Algal consumption rate was estimated using a coefficent of consumed biomass per bite, for each size class. The algal cover was sampled at 20 m linear transects with four replicates at each site. Food items were assessed sampling algae at the observed bitten substrates. Compared to Acuario, herbivores in IdO showed lower species richness and higher density of small size fishes, but large-sized parrotfish was almost absent due to intense fishing. The highest bite rate was observed for the smallest fish size, but net consumption rate was three times greater for medium and great size fishes, which were more abundant in the protected area. Algal cover was lower in Acuario, while in IdO it was very high, and coral cover was very low. In both locations epiphytic algae were the preferred food. These results support generalizations referring to the importance of great size herbivores fishes in controlling excesive algal proliferation on coral reefs.

  12. Biomechanical trade-offs bias rates of evolution in the feeding apparatus of fishes.

    PubMed

    Holzman, Roi; Collar, David C; Price, Samantha A; Hulsey, C Darrin; Thomson, Robert C; Wainwright, Peter C

    2012-04-01

    Morphological diversification does not proceed evenly across the organism. Some body parts tend to evolve at higher rates than others, and these rate biases are often attributed to sexual and natural selection or to genetic constraints. We hypothesized that variation in the rates of morphological evolution among body parts could also be related to the performance consequences of the functional systems that make up the body. Specifically, we tested the widely held expectation that the rate of evolution for a trait is negatively correlated with the strength of biomechanical trade-offs to which it is exposed. We quantified the magnitude of trade-offs acting on the morphological components of three feeding-related functional systems in four radiations of teleost fishes. After accounting for differences in the rates of morphological evolution between radiations, we found that traits that contribute more to performance trade-offs tend to evolve more rapidly, contrary to the prediction. While ecological and genetic factors are known to have strong effects on rates of phenotypic evolution, this study highlights the role of the biomechanical architecture of functional systems in biasing the rates and direction of trait evolution.

  13. Sensing the strike of a predator fish depends on the specific gravity of a prey fish.

    PubMed

    Stewart, William J; McHenry, Matthew J

    2010-11-15

    The ability of a predator fish to capture a prey fish depends on the hydrodynamics of the prey and its behavioral response to the predator's strike. Despite the importance of this predator-prey interaction to the ecology and evolution of a diversity of fish, it is unclear what factors dictate a fish's ability to evade capture. The present study evaluated how the specific gravity of a prey fish's body affects the kinematics of prey capture and the signals detected by the lateral line system of the prey during the strike of a suction-feeding predator. The specific gravity of zebrafish (Danio rerio) larvae was measured with high precision from recordings of terminal velocity in solutions of varying density. This novel method found that specific gravity decreased by ∼5% (from 1.063, N=8, to 1.011, N=35) when the swim bladder inflates. To examine the functional consequences of this change, we developed a mathematical model of the hydrodynamics of prey in the flow field created by a suction-feeding predator. This model found that the observed decrease in specific gravity due to swim bladder inflation causes an 80% reduction of the flow velocity around the prey's body. Therefore, swim bladder inflation causes a substantial reduction in the flow signal that may be sensed by the lateral line system to evade capture. These findings demonstrate that the ability of a prey fish to sense a predator depends crucially on the specific gravity of the prey.

  14. Suction muffler for refrigeration compressor

    DOEpatents

    Nelson, Richard T.; Middleton, Marc G.

    1983-01-01

    A hermetic refrigeration compressor includes a suction muffler formed from two pieces of plastic material mounted on the cylinder housing. One piece is cylindrical in shape with an end wall having an aperture for receiving a suction tube connected to the cylinder head. The other piece fits over and covers the other end of the cylindrical piece, and includes a flaring entrance horn which extends toward the return line on the sidewall of the compressor shell.

  15. Suction muffler for refrigeration compressor

    DOEpatents

    Nelson, R.T.; Middleton, M.G.

    1983-01-25

    A hermetic refrigeration compressor includes a suction muffler formed from two pieces of plastic material mounted on the cylinder housing. One piece is cylindrical in shape with an end wall having an aperture for receiving a suction tube connected to the cylinder head. The other piece fits over and covers the other end of the cylindrical piece, and includes a flaring entrance horn which extends toward the return line on the sidewall of the compressor shell. 5 figs.

  16. Microbial protein production in activated suspension tanks manipulating C:N ratio in feed and the implications for fish culture.

    PubMed

    Azim, M E; Little, D C; Bron, J E

    2008-06-01

    The present experiment investigated the possibility of microbial protein production in 250 l indoor tanks by manipulating C:N ratio in fish feed applied. Two different levels of protein feed (35% and 22% CP) resulting in C:N ratio of 8.4 and 11.6, respectively, were applied at 25 g daily in each tank. Tanks were aerated and agitated continuously using a dome diffuser. The experiment was carried out for eight weeks. The biofloc development in terms of VSS and BOD5 was better in the low protein fed tanks than in the high protein fed tanks. An estimated biofloc productivity ranged 3-5 g Cm(-3)day(-1). A 3-D image stained with DAPI indicates that the biofloc is comprised of hundreds of bacterial nuclei, size being ranged from 100 to 200 microm. Biofloc quality was independent of the quality of feed applied and contained more than 50% crude protein, 2.5% crude lipid, 4% fibre, 7% ash and 22 kJ g(-1) energy on dry matter basis. The dietary composition and size of biofloc can be considered as appropriate for all omnivorous fish species. The underlying ecological processes are explained through factor analysis. The potential of using biofloc in fish culture is also discussed. PMID:17869097

  17. Microbial protein production in activated suspension tanks manipulating C:N ratio in feed and the implications for fish culture.

    PubMed

    Azim, M E; Little, D C; Bron, J E

    2008-06-01

    The present experiment investigated the possibility of microbial protein production in 250 l indoor tanks by manipulating C:N ratio in fish feed applied. Two different levels of protein feed (35% and 22% CP) resulting in C:N ratio of 8.4 and 11.6, respectively, were applied at 25 g daily in each tank. Tanks were aerated and agitated continuously using a dome diffuser. The experiment was carried out for eight weeks. The biofloc development in terms of VSS and BOD5 was better in the low protein fed tanks than in the high protein fed tanks. An estimated biofloc productivity ranged 3-5 g Cm(-3)day(-1). A 3-D image stained with DAPI indicates that the biofloc is comprised of hundreds of bacterial nuclei, size being ranged from 100 to 200 microm. Biofloc quality was independent of the quality of feed applied and contained more than 50% crude protein, 2.5% crude lipid, 4% fibre, 7% ash and 22 kJ g(-1) energy on dry matter basis. The dietary composition and size of biofloc can be considered as appropriate for all omnivorous fish species. The underlying ecological processes are explained through factor analysis. The potential of using biofloc in fish culture is also discussed.

  18. Resting metabolism and heat increment of feeding in mandarin fish (Siniperca chuatsi) and Chinese snakehead (Channa argus).

    PubMed

    Liu, J; Cui, Y; Liu, J

    2000-10-01

    Resting metabolism was measured in immature mandarin fish Siniperca chuatsi weighing 42.1-510.2 g and Chinese snakehead Channa argus weighing 41.5-510.3 g at 10, 15, 20, 25, 30 and 35 degrees C. Heat increment of feeding was measured in mandarin fish weighing 202.0 (+/-14.0) g and snakehead weighing 200.8 (+/-19.3) g fed swamp loach Misgurnus anguillicaudatus at 1% body weight per day at 28 degrees C. In both species, weight exponent in the power relationship between resting metabolism and body weight was not affected by temperature. The relationship between resting metabolism and temperature could be described by a power function. The temperature exponent was 1.39 in mandarin fish and 2.10 in snakehead (P<0.05), indicating that resting metabolism in snakehead increased with temperature at a faster rate than in mandarin fish. Multiple regression models were used to describe the effects of body weight (W, g) and temperature (T, degrees C) on the resting metabolism (R(s), mg O(2)/h): lnR(s)=-5.343+0.772 lnW+1.387 lnT for the mandarin fish and lnR(s)=-7.863+0.801 lnW+2.104 lnT for the Chinese snakehead. The proportion of food energy channelled to heat increment was 8.7% in mandarin fish and 6.8% in snakehead.

  19. Influence of substrate orientation on feeding kinematics and performance of algae-grazing Lake Malawi cichlid fishes.

    PubMed

    Rupp, Maxwell F; Hulsey, C Darrin

    2014-09-01

    Lake Malawi cichlids have been studied extensively in an effort to elucidate the mechanisms underlying their adaptive radiation. Both habitat partitioning and trophic specialization have been suggested to be critical ecological axes underlying the exceptional diversification of these fishes, but the mechanisms facilitating this divergence are often unclear. For instance, in the rock-dwelling mbuna of Lake Malawi, coexistence is likely tightly linked to how and where species feed on the algae coating all the surfaces of the rocky reefs they exclusively inhabit. Yet, although mbuna species often preferentially graze from particular substrate orientations, we understand very little about how substrate orientation influences feeding kinematics or feeding rates in any group of organisms. Therefore, for three species of mbuna, we quantified feeding kinematics and inferred the rates that algae could be ingested on substrates that mimicked the top, side and bottom of the algae-covered boulders these species utilize in Lake Malawi. A number of differences in feeding kinematics were found among species, and several of the kinematic variables were found to differ even within species when the fish grazed from different surface orientations. However, despite their preferences for particular microhabitats, we found no evidence for clear trade-offs in the rates that the three species were inferred to be able to obtain algae from different substrate orientations. Nevertheless, our results indicate microhabitat divergence linked to differences in feeding kinematics could have played a role in the origin and maintenance of the vast diversity of co-occurring Lake Malawi mbuna species. PMID:24948641

  20. Mexican blind cavefish use mouth suction to detect obstacles.

    PubMed

    Holzman, Roi; Perkol-Finkel, Shimrit; Zilman, Gregory

    2014-06-01

    Fish commonly use their lateral line system to detect moving bodies such as prey and predators. A remarkable case is the Mexican blind cavefish Astyanax fasciatus, which evolved the ability to detect non-moving obstacles. The swimming body of A. fasciatus generates fluid disturbances, the alteration of which by an obstacle can be sensed by the fish's lateral line system. It is generally accepted that these alterations can provide information on the distance to the obstacle. We observed that A. fasciatus swimming in an unfamiliar environment open and close their mouths at high frequency (0.7-4.5 Hz) in order to generate suction flows. We hypothesized that repeated mouth suction generates a hydrodynamic velocity field, which is altered by an obstacle, inducing pressure gradients in the neuromasts of the lateral line and corresponding strong lateral line stimuli. We observed that the frequency and rate of mouth-opening events varied with the fish's distance to obstacles, a hallmark of pulse-based navigation mechanisms such as echolocation. We formulated a mathematical model of this hitherto unrecognized mechanism of obstacle detection and parameterized it experimentally. This model suggests that suction flows induce lateral line stimuli that are weakly dependent on the fish's speed, and may be an order of magnitude stronger than the correspondent stimuli induced by the fish's gliding body. We illustrate that A. fasciatus can navigate non-visually using a combination of two deeply ancestral and highly conserved mechanisms of ray-finned fishes: the mechanism of sensing water motion by the lateral line system and the mechanism of generating water motion by mouth suction. PMID:24675558

  1. Fish meal in animal feed and human exposure to persistent bioaccumulative and toxic substances.

    PubMed

    Dórea, José G

    2006-11-01

    Persistent and bioaccumulative toxic substances (PBTSs) that end up in fish are health hazards and the object of fish-consumption advisories. Some of these substances are present as extraneous contaminants, e.g., man-made lipophilic pollutants such as organohalogen pollutants, and others such as monomethyl mercury can be considered naturally occurring. Omnivores (e.g., poultry and swine) and especially ruminants that are fed contaminated fish meal can pass monomethyl mercury and organohalogen pollutants to eggs, meat, and dairy products. Differences in fish meal PBTS profiles and farm animal (e.g., poultry, swine, cattle, and farmed fish) physiology modulate PBTSs in animal products. Fish-consumption advisories issued to protect human health do not extend to fish by-products fed to farmed animals. Animals (especially farmed fish) that are fed fish meal can bioconcentrate monomethyl mercury in protein matrices, and organohalogen pollutants can be passed on in the fat components of derived foods. Policies to decrease exposure to monomethyl mercury and organohalogen pollutants must consider farming practices that use fish by-products. A risk assessment of toxic contaminants in fish meal may indicate that food safety objectives must consider the human health impact of foods derived from animals fed contaminated meal.

  2. Small estuarine fishes feed on large trematode cercariae: Lab and field investigations

    USGS Publications Warehouse

    Kaplan, A.T.; Rebhal, S.; Lafferty, K.D.; Kuris, A.M.

    2009-01-01

    In aquatic ecosystems, dense populations of snails can shed millions of digenean trematode cercariae every day. These short-lived, free-living larvae are rich in energy and present a potential resource for consumers. We investigated whether estuarine fishes eat cercariae shed by trematodes of the estuarine snail Cerithidea californica. In aquaria we presented cercariae from 10 native trematode species to 6 species of native estuarine fishes. Many of these fishes readily engorged on cercariae. To determine if fishes ate cercariae in the field, we collected the most common fish species, Fundulus parvipinnis (California killifish), from shallow water on rising tides when snails shed cercariae. Of 61 killifish, 3 had recognizable cercariae in their gut. Because cercariae are common in this estuary, they could be frequent sources of energy for small fishes. In turn, predation on cercariae by fishes (and other predators) could also reduce the transmission success of trematodes. ?? 2009 American Society of Parasitologists.

  3. Daily rhythms of lipid metabolic gene expression in zebra fish liver: Response to light/dark and feeding cycles.

    PubMed

    Paredes, J F; López-Olmeda, J F; Martínez, F J; Sánchez-Vázquez, F J

    2015-01-01

    Despite numerous studies about fish nutrition and lipid metabolism, very little is known about the daily rhythm expression of lipogenesis and lipolysis genes. This research aimed to investigate the existence of daily rhythm expressions of the genes involved in lipid metabolism and their synchronization to different light/dark (LD) and feeding cycles in zebra fish liver. For this purpose, three groups of zebra fish were submitted to a 12:12 h LD cycle. A single daily meal was provided to each group at various times: in the middle of the light phase (ML); in the middle of the dark phase (MD); at random times. After 20 days of acclimation to these experimental conditions, liver samples were collected every 4 h in one 24-h cycle. The results revealed that most genes displayed a significant daily rhythm with an acrophase of expression in the dark phase. The acrophase of lipolytic genes (lipoprotein lipase - lpl, peroxisome proliferator-activated receptor - pparα and hydroxyacil CoA dehydrogenase - hadh) was displayed between ZT 02:17 h and ZT 18:31 h. That of lipogenic genes (leptin-a - lepa, peroxisome proliferator-activated receptor - pparγ, liver X receptor - lxr, insulin-like growth factor - igf1, sterol regulatory element-binding protein - srebp and fatty acid synthase - fas) was displayed between ZT 15:25 h and 20:06 h (dark phase). Feeding time barely influenced daily expression rhythms, except for lxr in the MD group, whose acrophase shifted by about 14 h compared with the ML group (ZT 04:31 h versus ZT 18:29 h, respectively). These results evidence a strong synchronization to the LD cycle, but not to feeding time, and most genes showed a nocturnal acrophase. These findings highlight the importance of considering light and feeding time to optimize lipid metabolism and feeding protocols in fish farming. PMID:26595085

  4. Application of mercury isotopes for tracing trophic transfer and internal distribution of mercury in marine fish feeding experiments.

    PubMed

    Kwon, Sae Yun; Blum, Joel D; Chirby, Michelle A; Chesney, Edward J

    2013-10-01

    Feeding experiments were performed to investigate mercury (Hg) isotope fractionation during trophic transfer and internal distribution of total Hg (THg) in marine fish on exposure to natural seafood. Young-of-the-year amberjack (Seriola dumerili) were fed with either blackfin tuna (Thunnus atlanticus; 2647 ng/g THg) or brown shrimp (Farfantepenaeus aztecus; 25.1 ng/g THg) for 80 d or 50 d, respectively, and dissected for muscle, liver, kidney, brain, and blood. After 30 d of tuna consumption, Hg isotopes (δ(202) Hg and Δ(199)Hg) of the amberjack organs shifted to the tuna value (δ(202)Hg = 0.55‰, Δ(199)Hg = 1.54‰,), demonstrating the absence of Hg isotope fractionation. When amberjack were fed a shrimp diet, there was an initial mixing of the amberjack organs toward the shrimp value (δ(202)Hg = -0.48‰, Δ(199)Hg = 0.32‰), followed by a cessation of further shifts in Δ(199)Hg and a small shift in δ(202)Hg. The failure of Δ(199)Hg to reach the shrimp value can be attributed to a reduction in Hg bioaccumulation from shrimp resulting from feeding inhibition and the δ(202)Hg shift can be attributed to a small internal fractionation during excretion. Given that the feeding rate and Hg concentration of the diet can influence internal Hg isotope distribution, these parameters must be considered in biosentinel fish studies. PMID:23787815

  5. Diel changes in food and feeding activity of sciaenid fishes from the South-western Atlantic, Brazil.

    PubMed

    Soares, L S; Vazzoler, A E

    2001-05-01

    Food habits and daily feeding activity of fish populations are important ecological variables for understanding their role in the ecosystem. Diel changes in feeding activity and dietary composition of juvenile whitemouth croaker Micropogonias furnieri, shortfin corvina Isopisthus parvipinnis, shorthead drum Larimus breviceps and of juvenile and adult banded croaker Paralonchurus brasiliensis were investigated from samples taken over a 24 hours period from 4 to 5 September 1987 on the continental shelf off South-eastern Brazil. Whitemouth croaker and banded croaker had a benthic diet based on polychaetes and some caridean shrimps and showed no diel feeding pattern. Shortfin corvina and shorthead drum fed on crustaceans and teleostean fish, the former species primarily on pelagic sergestid shrimps and benthic caridean shrimps, and the latter mainly on pelagic sergestid shrimps, mysidacean and benthic caridean shrimps. Shortfin corvina is primarily a diurnal feeder, but preyed on some items only at night. Shorthead drum is a night feeder, with minimum stomach fullness values between dawn and daytime, and maximum values between dusk and night time.

  6. Environmental and water-quality operational studies. Prey selection and feeding patterns of fish in a Southern United States hydropower tailwater. Final report

    SciTech Connect

    Barwick, D.; Hudson, P.L.; Nestler, J.M.

    1985-10-01

    The downstream effects of peaking hydropower generation at Lake Hartwell Georgia-South Carolina, on the diel prey selection and feeding of four species of fish-silver redhorse (Moxostoma anisurum), redbreast sunfish (Lepomis auritus), green sunfish (L. cyanellus), and bluegill (L. macrochirus)--were determined. Aquatic insects (primarily dipterans, ephemeropterans, and trichopterans), crayfish, and terrestrial organisms (primarily insects) composed most of the food eaten. These fish fed primarily during daylight, before daily hydropower generation began, and little or no feeding occurred during generation. Consequently, few organisms entrained from the reservoir or displaced from the tailwater during hydropower generation were eaten by these fish.

  7. Radiocesium uptake, trophic transfer, and exposure in three estuarine fish with contrasting feeding habits.

    PubMed

    Pan, Ke; Wang, Wen-Xiong

    2016-11-01

    This study investigated the effects of different environmental factors on (137)Cs uptake in three subtropical estuarine fish, and the trophic transfer of (137)Cs in the fish from different preys. Our data showed that salinity, potassium, and temperature had appreciable effects on the dissolved uptake of (137)Cs in the fish, but no conclusive relationship was found between the effects of salinity and potassium concentration on the uptake. The dietary assimilation of (137)Cs was 51-55% in the omnivorous fish Siganus fuscescens when fed with macroalgae or bivalve tissues, and was much lower than those in carnivorous fish Sebastiscus marmoratus and Jarbua terapon (70-79%). Dietary pathway dominated the (137)Cs accumulation in the omnivorous and carnivorous fish, both of which exhibited strong potential to biomagnify (137)Cs from their preys. Using the biokinetic model, we demonstrated that salinity and temperature only had minor effects on the overall accumulation of (137)Cs in carnivorous species living in estuarine environment. Modeling calculation suggested that it would take 37-80 days for the fish to reach 95% of steady-state concentration, and lower somatic growth increased the time to reach steady-state in the fish. PMID:27565318

  8. Effect of feeding frequency on the daily rhythms of acidic digestion in a teleost fish (gilthead seabream).

    PubMed

    Yúfera, Manuel; Romero, María José; Pujante, Isabel M; Astola, Antonio; Mancera, Juan Miguel; Sánchez-Vázquez, F J; Moyano, Francisco Javier; Martínez-Rodríguez, Gonzalo

    2014-11-01

    Gilthead seabream is a fish species of great importance in Mediterranean aquaculture, attracting many studies on nutrition and chronobiology, although nothing is known about the effect of feeding frequency on the daily rhythms of the gastric digestion process. In this article, we investigated daily rhythms in stomach fullness, gastric and intestine pH, as well as pepsin activity and expression of pepsinogen and proton pump in juvenile fish under three different feeding protocols: (A) one daily meal at 9:00, (B) two daily meals at 9:00 and 17:00 and (C) continuous feeding during the daytime. The results revealed that feeding protocol affected significantly the rhythm of gastric pH and the pepsin activity pattern. The gastric pH exhibited significant daily rhythms in the three cases with the acrophase located at night in the regimes A and B and during daytime, in the regime C. In the regimes A and B, the pepsin activity peaked few hours after the meals, although the afternoon meal in B produced a higher peak. In the regime C, the peak occurred in the middle of the feeding period. Lowest total pepsin activity was observed in regime A, and the highest activity with the regime C. In contrast, the pepsinogen gene expression remained low along the daily cycle, with an expression peak just before or after the morning meal in regimes A and C, respectively. The proton pump gene expression was also practically constant with a peak right after the morning meal in the regime C. On the other hand, intestinal pH showed a postprandial increase after the first morning meal in all the three treatments, recovering the resting values in the dark period. Two meals and continuous feeding allowed a better and prolonged gastric digestion and consequently the juveniles exhibited better growth with the same daily ration of food. In short, while the gastric digestion pattern is mainly driven by pH changes induced by the time of food ingestion, the regulation of the intestinal digestion seems

  9. Development, validation and accreditation of a method for the determination of Pb, Cd, Cu and As in seafood and fish feed samples.

    PubMed

    Psoma, A K; Pasias, I N; Rousis, N I; Barkonikos, K A; Thomaidis, N S

    2014-05-15

    A rapid, sensitive, accurate and precise method for the determination of Pb, Cd, As and Cu in seafood and fish feed samples by Simultaneous Electrothermal Atomic Absorption Spectrometry was developed in regard to Council Directive 333/2007EC and ISO/IEC 17025 (2005). Different approaches were investigated in order to shorten the analysis time, always taking into account the sensitivity. For method validation, precision (repeatability and reproducibility) and accuracy by addition recovery tests have been assessed as performance criteria. The expanded uncertainties based on the Eurachem/Citac Guidelines were calculated. The method was accredited by the Hellenic Accreditation System and it was applied for an 8 years study in seafood (n=202) and fish feeds (n=275) from the Greek market. The annual and seasonal variation of the elemental content and correlation among the elemental content in fish feeds and the respective fish samples were also accomplished. PMID:24423504

  10. Uptake and transmission of Toxoplasma gondii oocysts by migratory, filter-feeding fish.

    PubMed

    Massie, Gloeta N; Ware, Michael W; Villegas, Eric N; Black, Michael W

    2010-05-11

    From bottlenose dolphins, to walruses, to sea otters, the parasitic protozoan Toxoplasma gondii is infecting marine mammals around the world. Whereas the terrestrial transmission pathways of T. gondii are well-described, the transmission pathway by which marine mammals are being infected is unknown. We hypothesize that migratory filter feeders, specifically northern anchovies (Engraulis mordax) and Pacific sardines (Sardinops sagax), are serving as biotic vectors for T. gondii within the marine environment. By filtering oocysts from seawater, these fishes could be transporting the oocysts from nearshore to pelagic environments. In this study, we experimentally exposed northern anchovies and Pacific sardines to T. gondii oocysts under laboratory conditions. Following exposure, the fishes' alimentary canals were harvested and assayed for the presence of T. gondii by PCR. Fish exposed to as few as 1197 oocysts/L seawater tested positive for T. gondii by PCR. In total, the PCR assay detected T. gondii DNA in 66% (40/61) of the exposed fishes. Oocyst infectivity was confirmed by mouse bioassay: 30% (7/23) of mice developed toxoplasmosis when fed fish exposed to 100,000 oocysts/L. This study demonstrates that both northern anchovies and Pacific sardines can filter T. gondii oocysts out of seawater under experimental conditions. Our experiments with anchovies demonstrated that the oocysts persisted in the fish for at least 8h post-exposure and our experiments with sardines demonstrated that the oocysts remained infectious inside the fish's alimentary canals. PMID:20097009

  11. Protecting the hand that feeds us: seagrass (Zostera marina) serves as commercial juvenile fish habitat.

    PubMed

    Bertelli, Chiara M; Unsworth, Richard K F

    2014-06-30

    Although fisheries are of major economic and food security importance we still know little about specific juvenile habitats that support such production. This is a major issue given the degradation to and lack of protection afforded to potential juvenile habitats such as seagrass meadows. In the present study we investigate the role of seagrass in supporting juvenile fish of commercial value. By assessing seagrass relative to adjacent sand we determined the presence of abundant juvenile fish. Nine commercial species were recorded and the most abundant of these were Plaice, Pollock and Herring. We provide the first quantitative evidence of the presence of juvenile fish of commercial value in seagrass surrounding Great Britain. Although the species that we found in seagrass as juveniles are not obligate seagrass users the resources that seagrass meadows offer to these fish provide significant long-term fitness benefits, potentially enhancing the whole population. PMID:23998854

  12. Protecting the hand that feeds us: seagrass (Zostera marina) serves as commercial juvenile fish habitat.

    PubMed

    Bertelli, Chiara M; Unsworth, Richard K F

    2014-06-30

    Although fisheries are of major economic and food security importance we still know little about specific juvenile habitats that support such production. This is a major issue given the degradation to and lack of protection afforded to potential juvenile habitats such as seagrass meadows. In the present study we investigate the role of seagrass in supporting juvenile fish of commercial value. By assessing seagrass relative to adjacent sand we determined the presence of abundant juvenile fish. Nine commercial species were recorded and the most abundant of these were Plaice, Pollock and Herring. We provide the first quantitative evidence of the presence of juvenile fish of commercial value in seagrass surrounding Great Britain. Although the species that we found in seagrass as juveniles are not obligate seagrass users the resources that seagrass meadows offer to these fish provide significant long-term fitness benefits, potentially enhancing the whole population.

  13. Effects of the timing of initial feeding on growth and survival of spotted mandarin fish Siniperca scherzeri larvae.

    PubMed

    Zhang, L; Wang, Y J; Hu, M H; Fan, Q X; Chenung, S G; Shin, P K S; Li, H; Cao, L

    2009-10-01

    The effects of delayed first feeding on growth and survival of spotted mandarin fish Siniperca scherzeri larvae were examined under controlled conditions. Morphometric characters [yolk-sac volume, oil globule volume, head depth (H(D)), body depth (B(D)), eye diameter (E(D)), musculature height (M(H)), mouth diameter (M(D)) and total length (L(T))], body mass (M), specific growth rate (S(GR)) and survival were evaluated under different first-feeding time (2, 3, 4 and 5 days after hatching). Larvae began to feed exogenously at 2 days after hatching (DAH) and the point of no return (P(NR)) occurred between 5 and 6 DAH at 23 degrees C, range +/-1.0 degrees C. The yolk volume of larvae first-fed at 2 days had a significant difference compared with that of larvae first-fed at 3, 4 and 5 days on 3 and 4 DAH. The larvae first-fed at 2 days achieved comparatively better growth performance than that of 3, 4 and 5 days. On 5 DAH, all morphometric characters had significant differences between 2 and 5 days and 2 and 4 days initial feeding, respectively. Total mortality was recorded on 9 DAH for the larvae first-fed at 5 days. On 12 DAH, significant differences were observed between 2 and 4 days and 3 and 4 days initial feeding for all morphometric characters. From 16 DAH to the end of experiment, all growth variables of the larvae first-fed at 2 days were significantly higher than those in other treatments. The S(GR) (2-9 DAH) first-fed at 2 and 3 days were significantly higher than 4 and 5 day treatments, and the S(GR) (9-16 DAH) first-fed at 2 days was significantly higher than 3 and 4 day treatments. There was no significant difference, however, of S(GR) (16-28 DAH) among treatments. Survival rate was significantly higher at 2 days initial feeding (27.42%) when compared with 3 (15.96%) and 4 days (7.92%) initial feeding at the end of experiment. The present study suggests that the first feeding of S. scherzeri larvae should be initiated at 2 days after hatching for

  14. Myosin heavy chain and parvalbumin expression in swimming and feeding muscles of centrarchid fishes: the molecular basis of the scaling of contractile properties.

    PubMed

    Campion, L A; Choi, S; Mistry, H L; Coughlin, D J

    2012-10-01

    In centrarchid fishes, such as bluegill (Lepomis macrochirus, Rafinesque) and largemouth bass (Micropterus salmoides, Lacepède), the contractile properties of feeding and swimming muscles show different scaling patterns. While the maximum shortening velocity (V(max)) and rate of relaxation from tetanus of swimming or myotomal muscle slow with growth, the feeding muscle shows distinctive scaling patterns. Cranial epaxial muscle, which is used to elevate the head during feeding strikes, retains fast contractile properties across a range of fish sizes in both species. In bass, the sternohyoideous muscle, which depresses the floor of the mouth during feeding strikes, shows faster contractile properties with growth. The objective of this study was to determine the molecular basis of these different scaling patterns. We examined the expression of two muscle proteins, myosin heavy chain (MyHC) and parvalbumin (PV), that affect contractile properties. We hypothesized that the relative contribution of slow and fast MyHC isoforms will modulate V(max) in these fishes, while the presence of PV in muscle will enhance rates of muscle relaxation. Myotomal muscle displays an increase in sMyHC expression with growth, in agreement with its physiological properties. Feeding muscles such as epaxial and sternohyoideus show no change or a decrease in sMyHC expression with growth, again as predicted from contractile properties. PV expression in myotomal muscle decreases with growth in both species, as has been seen in other fishes. The feeding muscles again show no change or an increase in PV expression with growth, contributing to faster contractile properties in these fishes. Both MyHC and PV appear to play important roles in modulating muscle contractile properties of swimming and feeding muscles in centrarchid fishes. PMID:22705556

  15. Economic values of growth and feed efficiency for fish farming in recirculating aquaculture system with density and nitrogen output limitations: a case study with African catfish (Clarias gariepinus).

    PubMed

    Besson, M; Komen, H; Aubin, J; de Boer, I J M; Poelman, M; Quillet, E; Vancoillie, C; Vandeputte, M; van Arendonk, J A M

    2014-12-01

    In fish farming, economic values (EV) of breeding goal traits are lacking, even though they are key parameters when defining selection objectives. The aim of this study was to develop a bioeconomic model to estimate EV of 2 traits representing production performances in fish farming: the thermal growth coefficient (TGC) and the feed conversion ratio (FCR). This approach was applied to a farm producing African catfish (Clarias gariepinus) in a recirculating aquaculture system (RAS). In the RAS, 2 factors could limit production level: the nitrogen treatment capacity of the biofilter or the fish density in rearing tanks at harvest. Profit calculation includes revenue from fish sales, cost of juveniles, cost of feed, cost of waste water treatment, and fixed costs. In the reference scenario, profit was modeled to zero. EV were calculated as the difference in profit per kilogram of fish between the current population mean for both traits (µt) and the next generation of selective breeding (µt+Δt) for either TGC or FCR. EV of TGC and FCR were calculated for three generations of hypothetical selection on either TGC or FCR (respectively 6.8% and 7.6% improvement per generation). The results show that changes in TGC and FCR can affect both the number of fish that can be stocked (number of batches per year and number of fish per batch) and the factor limiting production. The EV of TGC and FCR vary and depend on the limiting factors. When dissolved NH3-N is the limiting factor for both µt and µt+Δt, increasing TGC decreases the number of fish that can be stocked but increases the number of batches that can be grown. As a result, profit remains constant and EVTGC is zero. Increasing FCR, however, increases the number of fish stocked and the ratio of fish produced per kilogram of feed consumed ("economic efficiency"). The EVFCR is 0.14 €/kg of fish, and profit per kilogram of fish increases by about 10%. When density is the limiting factor for both µt and µt+Δt, the

  16. Polychlorinated Biphenyls (PCBs) in Predator and Bottom-Feeding Fish from Abiquiu and Cochiti Reservoirs in North-Central New Mexico

    SciTech Connect

    G.J. Gonzales, P.R. Fresquez

    2006-03-01

    Concern has existed for years that the Los Alamos National Laboratory (LANL), a complex of nuclear weapons research and support facilities, has released polychlorinated biphenyls (PCBs) to the environment that may have reached adjacent bodies of water through canyons that connect them. In 1997, we began measuring PCBs in fish in the Rio Grande upstream and downstream of ephemeral streams that cross LANL and later began sampling fish in Abiquiu and Cochiti reservoirs, which are situated on the Rio Chama and Rio Grande upstream and downstream of LANL, respectively. In 2005, six species of fish from Abiquiu and Cochiti reservoirs were collected and the edible portion (fillets) was analyzed for 209 possible PCB congeners. Fish from the reservoirs were last sampled in 2001. Mean total PCB concentrations in fish from Abiquiu Reservoir ({mu} = 2.4 ng/g) were statistically similar ({alpha} = 0.01; P (T{le}t) [range = 0.23-0.71]) to mean total PCB concentrations in fish from Cochiti Reservoir ({mu} = 2.7 ng/g), implying that LANL is not the source of PCBs in fish in Cochiti Reservoir. The levels of PCBs in fish from Cochiti Reservoir generally appear to be declining, at least since 2001, which is when PCB levels might have peaked resulting from storm water runoff after the Cerro Grande Fire. Although a PCB ''fingerprinting'' method can be used to relate PCB ''signatures'' in one area to signatures in another area, this method of implicating the source of PCBs cannot be effectively used for biota because they alter the PCB signature through metabolic processes. Regardless of the source of the PCBs, certain species of fish (catfish and carpsuckers) at both Abiquiu and Cochiti reservoirs continue to harbor levels of PCBs that could be harmful to human health if they are consistently eaten over a long period of time. Bottom-feeding fish (carpsucker and catfish) from Cochiti Reservoir contained statistically higher levels of total PCBs ({mu} = 4.25 ng/g-fillet-wet) than predator

  17. Economic values of growth and feed efficiency for fish farming in recirculating aquaculture system with density and nitrogen output limitations: a case study with African catfish (Clarias gariepinus).

    PubMed

    Besson, M; Komen, H; Aubin, J; de Boer, I J M; Poelman, M; Quillet, E; Vancoillie, C; Vandeputte, M; van Arendonk, J A M

    2014-12-01

    In fish farming, economic values (EV) of breeding goal traits are lacking, even though they are key parameters when defining selection objectives. The aim of this study was to develop a bioeconomic model to estimate EV of 2 traits representing production performances in fish farming: the thermal growth coefficient (TGC) and the feed conversion ratio (FCR). This approach was applied to a farm producing African catfish (Clarias gariepinus) in a recirculating aquaculture system (RAS). In the RAS, 2 factors could limit production level: the nitrogen treatment capacity of the biofilter or the fish density in rearing tanks at harvest. Profit calculation includes revenue from fish sales, cost of juveniles, cost of feed, cost of waste water treatment, and fixed costs. In the reference scenario, profit was modeled to zero. EV were calculated as the difference in profit per kilogram of fish between the current population mean for both traits (µt) and the next generation of selective breeding (µt+Δt) for either TGC or FCR. EV of TGC and FCR were calculated for three generations of hypothetical selection on either TGC or FCR (respectively 6.8% and 7.6% improvement per generation). The results show that changes in TGC and FCR can affect both the number of fish that can be stocked (number of batches per year and number of fish per batch) and the factor limiting production. The EV of TGC and FCR vary and depend on the limiting factors. When dissolved NH3-N is the limiting factor for both µt and µt+Δt, increasing TGC decreases the number of fish that can be stocked but increases the number of batches that can be grown. As a result, profit remains constant and EVTGC is zero. Increasing FCR, however, increases the number of fish stocked and the ratio of fish produced per kilogram of feed consumed ("economic efficiency"). The EVFCR is 0.14 €/kg of fish, and profit per kilogram of fish increases by about 10%. When density is the limiting factor for both µt and µt+Δt, the

  18. Effect of substituting live feed with formulated feed on the reproductive performance and fry survival of Siamese fighting fish, Betta splendens (Regan, 1910).

    PubMed

    Mandal, Sagar C; Kohli, Mahinder P S; Das, Pronob; Singh, Soibam K; Munilkumar, Sukham; Sarma, Kamal; Baruah, Kartik

    2012-04-01

    This study aimed to elucidate the effect of partial or complete replacement of live feed (LF) (Tubifex) with formulated feed (FF) on the reproductive performance of Betta splendens. Three hundred B. splendens fry (average weight 0.19 ± 0.01 g) were equally distributed into five different groups, each with three replicates. They were fed for 105 days with following different diets: control (C)-100% LF; T1-75% LF, 25% FF; T2-50% LF, 50% FF; T3-25% LF, 75% FF, and T4-100% FF. Results showed that the average number of hatched larvae (654 ± 101) and fry survival after 2 weeks of rearing (428 ± 70), after completion of three spawning, were recorded highest in the control group, which was, however, not significantly different from the T1, T2, and T3 groups. At the end of the feeding trial, the highest hatching percentage (90.3%) was registered in the T2 group, which was not significantly different from the control and T1 groups. The T2 group also recorded highest fry survival (65.54%) after completion of three spawning, which was not significantly (P < 0.05) different from the T1 and T3 groups. Control diet contained higher saturated fatty acid (63.23%) than formulated diet (29.80%). In the whole-body tissue, highest level of EPA (0.42%) and DHA (3.13%) were found in the T4 group followed by T3 group. The DHA/EPA ration was recorded highest in the T2 group (10.96%), which did not differ significantly from the T1 and T3 groups. Significant positive correlation was observed between saturated fatty acid levels in fish whole-body tissue and number of hatched larvae (Y = 30.81 × -825.3, R(2) = 0.968) and fry survival after 2 weeks of rearing (Y = 21.38 × -580.9, R(2) = 0.967). Considering all these factors, it can be concluded that the live feed Tubifex can be replaced up to 50% without any adverse effect on the reproductive performance and fry survival of B. splendens.

  19. Effect of substituting live feed with formulated feed on the reproductive performance and fry survival of Siamese fighting fish, Betta splendens (Regan, 1910).

    PubMed

    Mandal, Sagar C; Kohli, Mahinder P S; Das, Pronob; Singh, Soibam K; Munilkumar, Sukham; Sarma, Kamal; Baruah, Kartik

    2012-04-01

    This study aimed to elucidate the effect of partial or complete replacement of live feed (LF) (Tubifex) with formulated feed (FF) on the reproductive performance of Betta splendens. Three hundred B. splendens fry (average weight 0.19 ± 0.01 g) were equally distributed into five different groups, each with three replicates. They were fed for 105 days with following different diets: control (C)-100% LF; T1-75% LF, 25% FF; T2-50% LF, 50% FF; T3-25% LF, 75% FF, and T4-100% FF. Results showed that the average number of hatched larvae (654 ± 101) and fry survival after 2 weeks of rearing (428 ± 70), after completion of three spawning, were recorded highest in the control group, which was, however, not significantly different from the T1, T2, and T3 groups. At the end of the feeding trial, the highest hatching percentage (90.3%) was registered in the T2 group, which was not significantly different from the control and T1 groups. The T2 group also recorded highest fry survival (65.54%) after completion of three spawning, which was not significantly (P < 0.05) different from the T1 and T3 groups. Control diet contained higher saturated fatty acid (63.23%) than formulated diet (29.80%). In the whole-body tissue, highest level of EPA (0.42%) and DHA (3.13%) were found in the T4 group followed by T3 group. The DHA/EPA ration was recorded highest in the T2 group (10.96%), which did not differ significantly from the T1 and T3 groups. Significant positive correlation was observed between saturated fatty acid levels in fish whole-body tissue and number of hatched larvae (Y = 30.81 × -825.3, R(2) = 0.968) and fry survival after 2 weeks of rearing (Y = 21.38 × -580.9, R(2) = 0.967). Considering all these factors, it can be concluded that the live feed Tubifex can be replaced up to 50% without any adverse effect on the reproductive performance and fry survival of B. splendens. PMID:21710171

  20. A rectangular capillary suction apparatus

    SciTech Connect

    Lee, D.J. . Dept. of Chemical Engineering); Hsu, Y.H. . Dept. of Chemical Engineering)

    1994-06-01

    Fluid flow and cake formation in a rectangular capillary suction apparatus (RCSA) are investigated experimentally and theoretically. Water, methanol, ethanol, and ethylene glycol are used to study the effects of liquid properties, and CaCO[sub 3], kaolin, and bentonite slurries are employed for studying the effects of cake formation on capillary suction-time (CST). A theory based on a diffusion-like approach is developed. The liquid saturation under the inner cell will approach a constant value when the wet front distance is large. A method based on this experimental finding for estimating the cake specific resistance is proposed. The agreement between experiments and calculations is close. The RCSA is superior to the cylindrical CSA when treating liquids with small diffusivities or slurries with high solid concentration and/or with high averaged specific resistance.

  1. Analysis of Tank 38H (HTF-38-15-119, 127) Surface, Subsurface and Tank 43H (HTF-43-15-116, 117 and 118) Surface, Feed Pump Suction and Jet Suction Subsurface Supernatant Samples in Support of Enrichment, Corrosion Control and Salt Batch Planning Programs

    SciTech Connect

    Oji, L.

    2015-12-17

    Compositional feed limits have been established to ensure that a nuclear criticality event for the 2H and 3H Evaporators is not possible. The Enrichment Control Program (ECP) requires feed sampling to determine the equivalent enriched uranium content prior to transfer of waste other than recycle transfers (requires sampling to determine the equivalent enriched uranium at two locations in Tanks 38H and 43H every 26 weeks) The Corrosion Control Program (CCP) establishes concentration and temperature limits for key constituents and periodic sampling and analysis to confirm that waste supernate is within these limits. This report provides the results of analyses on Tanks 38H and 43H surface and subsurface supernatant liquid samples in support of the ECP, the CCP, and the Salt Batch 10 Planning Program.

  2. Functional Feed Assessment on Litopenaeus vannamei Using 100% Fish Meal Replacement by Soybean Meal, High Levels of Complex Carbohydrates and Bacillus Probiotic Strains

    PubMed Central

    Olmos, Jorge; Ochoa, Leonel; Paniagua-Michel, Jesus; Contreras, Rosalia

    2011-01-01

    Functional feed supplemented with alternative-economic nutrient sources (protein, carbohydrates, lipids) and probiotics are being considered in shrimp/fish aquaculture production systems as an option to increase yield and profits and to reduce water pollution. In this study the probiotic potential to formulate functional feeds have been evaluated using four dietary treatments: Treatment 1 (B + Bs); Bacillus subtilis potential probiotic strain was supplemented to a soybeanmeal (SBM)—carbohydrates (CHO) basal feed. Treatment 2 (B + Bm); Bacillus megaterium potential probiotic strain was supplemented to the same SBM-CHO basal feed. In Treatment 3 (B); SBM-CHO basal feed was not supplemented with probiotic strains. Treatment 4 (C); fishmeal commercial feed (FM) was utilized as positive control. Feeding trials evaluated the survival, growth, and food conversion ratio and stress tolerance of juvenile Litopenaeus vannamei (Boone) Pacific white shrimp. Best overall shrimp performance was observed for animals fed with Treatment 1 (B+Bs); additionally, stress tolerance and hemolymph metabolites also showed the best performance in this treatment. SBM-CHO basal feed not supplemented with probiotic strains (B) presented smaller growth and lower feed conversion ratio (FCR). Shrimps fed with the fishmeal commercial feed (C) presented the lowest stress tolerance to high ammonia and low oxygen levels. Specifically selected B. subtilis strains are recommended to formulate functional and economical feeds containing high levels of vegetable; protein and carbohydrates as main dietary sources in L. vannamei cultures. PMID:21747750

  3. A game of keep-away: feeding the fish and not the pond

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phytic acid is a storage form of phosphorus in many plants. Its levels rise in the diet along with the inclusion rate of plant-based materials. Our measurements have found that phytic acid levels can be as high as 2% of catfish diets (40 lbs/ton of feed). However, phytic acid is largely indigestib...

  4. Evidence of a specialized feeding niche in a Late Triassic ray-finned fish: evolution of multidenticulate teeth and benthic scraping in † Hemicalypterus

    NASA Astrophysics Data System (ADS)

    Gibson, Sarah Z.

    2015-04-01

    Fishes have evolved to exploit multiple ecological niches. Extant fishes in both marine (e.g., rabbitfishes, surgeonfishes) and freshwater systems (e.g., haplochromine cichlids, characiforms) have evolved specialized, scoop-like, multidenticulate teeth for benthic scraping, feeding primarily on algae. Here, I report evidence of the oldest example of specialized multidenticulate dentition in a ray-finned fish, † Hemicalypterus weiri, from the Upper Triassic Chinle Formation of southeastern Utah (˜210-205 Ma), USA. † H. weiri is a lower actinopterygian species that is phylogenetically remote from modern fishes, and has evolved specialized teeth that converge with those of several living teleost fishes (e.g., characiforms, cichlids, acanthurids, siganids), with a likely function of these teeth being to scrape algae off a rock substrate. This finding contradicts previously held notions that fishes with multicuspid, scoop-like dentition were restricted to teleosts, and indicates that ray-finned fishes were diversifying into different trophic niches and exploring different modes of feeding earlier in their history than previously thought, fundamentally altering our perceptions of the ecological roles of fishes during the Mesozoic.

  5. Evidence of a specialized feeding niche in a Late Triassic ray-finned fish: evolution of multidenticulate teeth and benthic scraping in †Hemicalypterus.

    PubMed

    Gibson, Sarah Z

    2015-04-01

    Fishes have evolved to exploit multiple ecological niches. Extant fishes in both marine (e.g., rabbitfishes, surgeonfishes) and freshwater systems (e.g., haplochromine cichlids, characiforms) have evolved specialized, scoop-like, multidenticulate teeth for benthic scraping, feeding primarily on algae. Here, I report evidence of the oldest example of specialized multidenticulate dentition in a ray-finned fish, †Hemicalypterus weiri, from the Upper Triassic Chinle Formation of southeastern Utah (∼210-205 Ma), USA. †H. weiri is a lower actinopterygian species that is phylogenetically remote from modern fishes, and has evolved specialized teeth that converge with those of several living teleost fishes (e.g., characiforms, cichlids, acanthurids, siganids), with a likely function of these teeth being to scrape algae off a rock substrate. This finding contradicts previously held notions that fishes with multicuspid, scoop-like dentition were restricted to teleosts, and indicates that ray-finned fishes were diversifying into different trophic niches and exploring different modes of feeding earlier in their history than previously thought, fundamentally altering our perceptions of the ecological roles of fishes during the Mesozoic.

  6. Amending reduced fish-meal feeds with marine lecithin, but not soy lecithin, improves the growth of juvenile cobia and may attenuate heightened responses to stress challenge.

    PubMed

    Trushenski, J; Schwarz, M; Pessoa, W V N; Mulligan, B; Crouse, C; Gause, B; Yamamoto, F; Delbos, B

    2013-02-01

    Sparing of marine resources in aquafeeds can be environmentally and economically advantageous; however, fish meal (FM) replacement can affect the production performance and physiological competence. Phospholipids are increasingly understood to be involved in maintaining growth and vigour in fish and may be deficient in reduced FM formulations. Accordingly, we evaluated the growth and stress tolerance of juvenile cobia fed typical (50% FM) or reduced FM feeds (12% FM) with or without phospholipid amendment [1% marine lecithin (12% FM + Marine PL) or soy lecithin (12% FM + Soy PL)] for 6 weeks in triplicate tanks (N = 3) in a recirculation aquaculture system. The 50% FM feed yielded significantly superior growth and growth efficiency in comparison with the 12% FM and 12% FM+ Soy PL feeds, but the 12% FM+ Marine PL feed yielded comparable results to 50% FM feed. A low-water stress challenge induced elevated plasma glucose, cortisol and lactate levels in all treatments. However, a significant interaction (diet × stress) effect suggested a lesser cortisol response among fish fed the 12% FM+ Marine PL and 50% FM diets. These findings demonstrate that growth performance and, perhaps, resilience of cobia raised on reduced FM feeds may be improved by the addition of marine-origin phospholipid to the diet.

  7. Persistent organic pollutants (POPs) in fish with different feeding habits inhabiting a shallow lake ecosystem.

    PubMed

    Barni, María F Silva; Ondarza, Paola M; Gonzalez, Mariana; Da Cuña, Rodrigo; Meijide, Fernando; Grosman, Fabián; Sanzano, Pablo; Lo Nostro, Fabiana L; Miglioranza, Karina S B

    2016-04-15

    The occurrence of persistent organic pollutants (POPs) in the environment can affect organisms inhabiting aquatic systems, in particular shallow lakes that are vulnerable to environmental stressors. This study aimed to assess POPs accumulation and changes at histological and physiological levels in tissues of three fish species with different trophic habits. Gills, brain, muscle, liver and gonads of Odontesthes bonariensis, Oligosarcus jenynsii and Cyphocharax voga were collected from the shallow lake La Peregrina, located in an agricultural area from Argentina. In addition, contaminant levels in surface water (SW), suspended particulate matter (SPM) and bottom sediments (BS) were assessed. Histological lesions were evaluated in fish tissues and levels of vitellogenin (VTG) were assessed in plasma of male fish in order to correlate these alterations with the presence of POPs in the environment. Organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) were determined by GC-ECD. Biotic and abiotic samples showed the same POPs distribution pattern: OCPs>PCBs>PBDEs. Although tissue distribution of OCPs was species-specific, muscle showed the lowest levels in all species. The most abundant contaminants were endosulfans, suggesting their widespread use in the area. O. bonariensis showed the highest endosulfans levels in liver (184.2-219ngg(-1)wet w), which was associated with the high SPM levels considering this species is a filter feeder. The occurrence of PCBs and PBDEs shows the ubiquity of these pollutants in the area. Histological lesions in gills and liver of O. bonariensis and O. jenynsii, might be related with the high levels of endosulfans in these organs. The detection of VTG in males warns about a possible exposure to estrogenic compounds in the environment. In conclusion, the simultaneous exposure of fish to multiple environmental pollutants leads to different alterations, so measures should be taken in

  8. Persistent organic pollutants (POPs) in fish with different feeding habits inhabiting a shallow lake ecosystem.

    PubMed

    Barni, María F Silva; Ondarza, Paola M; Gonzalez, Mariana; Da Cuña, Rodrigo; Meijide, Fernando; Grosman, Fabián; Sanzano, Pablo; Lo Nostro, Fabiana L; Miglioranza, Karina S B

    2016-04-15

    The occurrence of persistent organic pollutants (POPs) in the environment can affect organisms inhabiting aquatic systems, in particular shallow lakes that are vulnerable to environmental stressors. This study aimed to assess POPs accumulation and changes at histological and physiological levels in tissues of three fish species with different trophic habits. Gills, brain, muscle, liver and gonads of Odontesthes bonariensis, Oligosarcus jenynsii and Cyphocharax voga were collected from the shallow lake La Peregrina, located in an agricultural area from Argentina. In addition, contaminant levels in surface water (SW), suspended particulate matter (SPM) and bottom sediments (BS) were assessed. Histological lesions were evaluated in fish tissues and levels of vitellogenin (VTG) were assessed in plasma of male fish in order to correlate these alterations with the presence of POPs in the environment. Organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) were determined by GC-ECD. Biotic and abiotic samples showed the same POPs distribution pattern: OCPs>PCBs>PBDEs. Although tissue distribution of OCPs was species-specific, muscle showed the lowest levels in all species. The most abundant contaminants were endosulfans, suggesting their widespread use in the area. O. bonariensis showed the highest endosulfans levels in liver (184.2-219ngg(-1)wet w), which was associated with the high SPM levels considering this species is a filter feeder. The occurrence of PCBs and PBDEs shows the ubiquity of these pollutants in the area. Histological lesions in gills and liver of O. bonariensis and O. jenynsii, might be related with the high levels of endosulfans in these organs. The detection of VTG in males warns about a possible exposure to estrogenic compounds in the environment. In conclusion, the simultaneous exposure of fish to multiple environmental pollutants leads to different alterations, so measures should be taken in

  9. Stochastic feeding of fish larvae and their metabolic handling of starvation

    NASA Astrophysics Data System (ADS)

    Augustine, S.; Litvak, M. K.; Kooijman, S. A. L. M.

    2011-11-01

    Developmental patterns of yolk-sac larvae are well captured by the standard DEB model: (i) when feeding is delayed post birth the size at which post-feeding growth begins is reduced but the rate of growth post-feeding is unaffected and (ii) maternal effects (initial energy in egg) show up as differences in condition at birth and maximum length of non fed individuals. We extended the standard DEB model in two ways to account for starvation. (I): if somatic maintenance can no longer be paid structure is also mobilized to cover the costs, but at an extra cost-conversion efficiency of structure to energy. Death occurs if structure reaches a fraction of the maximum at the onset of shrinking. (II): if maturity maintenance can no longer be paid then maturity level decays exponentially (rejuvenation). Hazard due to rejuvenation is proportional to the difference between maturity and the maximum maturity at the onset of rejuvenation. We performed Monte Carlo simulation studies which treat feeding as a random process to evaluate the contribution of the metabolic handling of starvation to early teleost life history. The simulations suggest that food density strongly impacts growth, energy reserves, mineral fluxes, hazard and mortality from shrinking. Environmental factors can soon override maternal induced differences between individuals. Moreover in the low food density, simulated individuals from eggs of lower caloric content experience mortality from shrinking earlier than their counterparts issued from higher energy eggs. Empirically observed patterns of real data, i.e. high scatter in respiration in combination with low scatter in lengths, can be expected when the metabolism is treated as a deterministic system while behaviourally controlled input is stochastic. At low food densities where mortality from shrinking reaches 10% almost all individuals experience hazard due to rejuvenation. This hazard is difficult to access experimentally but represents moments of heightened

  10. Hybrid striped bass feeds based on fish oil, beef tallow, and eicosapentaenoic acid/docosahexaenoic acid supplements: Insight regarding fish oil sparing and demand for -3 long-chain polyunsaturated fatty acids.

    PubMed

    Bowzer, J; Jackson, C; Trushenski, J

    2016-03-01

    Previous research suggests that saturated (SFA) and monounsaturated fatty acid (MUFA) rich lipids, including beef tallow, can make utilization or diet-to-tissue transfer of long-chain polyunsaturated fatty acids (LC-PUFA) more efficient. We hypothesized that using beef tallow as an alternative to fish oil may effectively reduce the LC-PUFA demand of hybrid striped bass × and allow for greater fish oil sparing. Accordingly, we evaluated growth performance and tissue fatty acid profiles of juvenile fish (23.7 ± 0.3 g) fed diets containing menhaden fish oil (considered an ideal source of LC-PUFA for this taxon), beef tallow (BEEF ONLY), or beef tallow amended with purified sources of eicosapentaenoic acid (EPA) and/or docosahexaenoic acid (DHA) to achieve levels corresponding to 50 or 100% of those observed in the FISH ONLY feed. Diets were randomly assigned to quadruplicate tanks of fish ( = 4; 10 fish/tank), and fish were fed assigned diets to apparent satiation once daily for 10 wk. Survival (98-100%) was equivalent among treatments, but weight gain (117-180%), specific growth rate (1.1-1.5% BW/d), feed intake (1.4-1.8% BW/d), thermal growth coefficient (0.50-0.70), and feed conversion ratio (FCR; 1.1-1.4, DM basis) varied. Except for FCR, no differences were observed between the FISH ONLY and BEEF ONLY treatments, but performance was generally numerically superior among fish fed the diets containing beef tallow supplemented with DHA at the 100% or both EPA and DHA at the 50% or 100% level. Tissue fatty acid composition was significantly distorted in favor among fish fed the beef tallow-based feeds; however, profile distortion was most overt in peripheral tissues. Results suggest that beef tallow may be used as a primary lipid source in practical diets for hybrid striped bass, but performance may be improved by supplementation with LC-PUFA, particularly DHA. Furthermore, our results suggest that -3 LC-PUFA requirements reported for hybrid striped bass may not be

  11. Hybrid striped bass feeds based on fish oil, beef tallow, and eicosapentaenoic acid/docosahexaenoic acid supplements: Insight regarding fish oil sparing and demand for -3 long-chain polyunsaturated fatty acids.

    PubMed

    Bowzer, J; Jackson, C; Trushenski, J

    2016-03-01

    Previous research suggests that saturated (SFA) and monounsaturated fatty acid (MUFA) rich lipids, including beef tallow, can make utilization or diet-to-tissue transfer of long-chain polyunsaturated fatty acids (LC-PUFA) more efficient. We hypothesized that using beef tallow as an alternative to fish oil may effectively reduce the LC-PUFA demand of hybrid striped bass × and allow for greater fish oil sparing. Accordingly, we evaluated growth performance and tissue fatty acid profiles of juvenile fish (23.7 ± 0.3 g) fed diets containing menhaden fish oil (considered an ideal source of LC-PUFA for this taxon), beef tallow (BEEF ONLY), or beef tallow amended with purified sources of eicosapentaenoic acid (EPA) and/or docosahexaenoic acid (DHA) to achieve levels corresponding to 50 or 100% of those observed in the FISH ONLY feed. Diets were randomly assigned to quadruplicate tanks of fish ( = 4; 10 fish/tank), and fish were fed assigned diets to apparent satiation once daily for 10 wk. Survival (98-100%) was equivalent among treatments, but weight gain (117-180%), specific growth rate (1.1-1.5% BW/d), feed intake (1.4-1.8% BW/d), thermal growth coefficient (0.50-0.70), and feed conversion ratio (FCR; 1.1-1.4, DM basis) varied. Except for FCR, no differences were observed between the FISH ONLY and BEEF ONLY treatments, but performance was generally numerically superior among fish fed the diets containing beef tallow supplemented with DHA at the 100% or both EPA and DHA at the 50% or 100% level. Tissue fatty acid composition was significantly distorted in favor among fish fed the beef tallow-based feeds; however, profile distortion was most overt in peripheral tissues. Results suggest that beef tallow may be used as a primary lipid source in practical diets for hybrid striped bass, but performance may be improved by supplementation with LC-PUFA, particularly DHA. Furthermore, our results suggest that -3 LC-PUFA requirements reported for hybrid striped bass may not be

  12. Optimum Suction Distribution for Transition Control

    NASA Technical Reports Server (NTRS)

    Balakumar, P.; Hall, P.

    1996-01-01

    The optimum suction distribution which gives the longest laminar region for a given total suction is computed. The goal here is to provide the designer with a method to find the best suction distribution subject to some overall constraint applied to the suction. We formulate the problem using the Lagrangian multiplier method with constraints. The resulting non-linear system of equations is solved using the Newton-Raphson technique. The computations are performed for a Blasius boundary layer on a flat-plate and crossflow cases. For the Blasius boundary layer, the optimum suction distribution peaks upstream of the maximum growth rate region and remains flat in the middle before it decreases to zero at the end of the transition point. For the stationary and travelling crossflow instability, the optimum suction peaks upstream of the maximum growth rate region and decreases gradually to zero.

  13. Spatial variations in feeding habits and trophic levels of two small pelagic fish species in the central Mediterranean Sea.

    PubMed

    Rumolo, P; Bonanno, A; Barra, M; Fanelli, E; Calabrò, M; Genovese, S; Ferreri, R; Mazzola, S; Basilone, G

    2016-04-01

    Trophic ecology of adults of European sardine (Sardina pilchardus) and anchovy (Engraulis encrasicolus) was examined and compared among various regions of central Mediterranean Sea. Carbon and nitrogen stable isotope analyses (δ(13)C and δ(15)N) were adopted as a tool to determine changes in feeding behaviour of adults of sardines and anchovies. In the study period (summer) a clear geographical pattern was recognized in the isotopic composition of both species, with an increasing trend northward. The highest variations in isotopic signal were linked to the geographical positions of the samples and, especially, between pairs of areas: South Sicily/South Campania and Gulf of Gaeta/South Elba. Higher isotope values were found in the anchovies and sardines caught in northern Tyrrhenian Sea, while lower values were mostly estimated in the southern region. Higher carbon and nitrogen isotopes may reflect a more coastal behaviour of both species, being (13)C-enriched source from benthic primary producers in addition to phytoplankton. Variations in the nitrogen isotope ratio may reflect not only differences in the trophic level of prey species, but also variations in the baseline level of food webs. Our results support the hypothesis that feeding behaviour of both species is directly or indirectly influenced by local factors, or by resource partitioning based on zooplankton size. Findings can supply knowledge needed for improving fish stock management and promoting plans able to take into account also local ecosystem analysis. PMID:26895386

  14. Spatial variations in feeding habits and trophic levels of two small pelagic fish species in the central Mediterranean Sea.

    PubMed

    Rumolo, P; Bonanno, A; Barra, M; Fanelli, E; Calabrò, M; Genovese, S; Ferreri, R; Mazzola, S; Basilone, G

    2016-04-01

    Trophic ecology of adults of European sardine (Sardina pilchardus) and anchovy (Engraulis encrasicolus) was examined and compared among various regions of central Mediterranean Sea. Carbon and nitrogen stable isotope analyses (δ(13)C and δ(15)N) were adopted as a tool to determine changes in feeding behaviour of adults of sardines and anchovies. In the study period (summer) a clear geographical pattern was recognized in the isotopic composition of both species, with an increasing trend northward. The highest variations in isotopic signal were linked to the geographical positions of the samples and, especially, between pairs of areas: South Sicily/South Campania and Gulf of Gaeta/South Elba. Higher isotope values were found in the anchovies and sardines caught in northern Tyrrhenian Sea, while lower values were mostly estimated in the southern region. Higher carbon and nitrogen isotopes may reflect a more coastal behaviour of both species, being (13)C-enriched source from benthic primary producers in addition to phytoplankton. Variations in the nitrogen isotope ratio may reflect not only differences in the trophic level of prey species, but also variations in the baseline level of food webs. Our results support the hypothesis that feeding behaviour of both species is directly or indirectly influenced by local factors, or by resource partitioning based on zooplankton size. Findings can supply knowledge needed for improving fish stock management and promoting plans able to take into account also local ecosystem analysis.

  15. Evaluation of Enterococcus spp. from rainbow trout (Oncorhynchus mykiss, Walbaum), feed, and rearing environment against fish pathogens.

    PubMed

    Araújo, Carlos; Muñoz-Atienza, Estefanía; Hernández, Pablo E; Herranz, Carmen; Cintas, Luis M; Igrejas, Gilberto; Poeta, Patrícia

    2015-04-01

    The use of lactic acid bacteria of aquatic origin as probiotics constitutes an alternative strategy to the antibiotic treatment for disease control in aquaculture. Enterococci are currently used as probiotics in human and animal health. In this study, we evaluated the safety of 64 enterococci isolated from rainbow trout (Oncorhynchus mykiss, Walbaum), feed and rearing environment, and their antimicrobial activity against 9 fish pathogens. The 64 enterococcal isolates were identified to the species level by polymerase chain reaction (PCR), using specific primers for the different enterococcal species, and confirmed by superoxide dismutase gene sequencing. Enterococcus faecium and E. hirae were the most common species (42.2 and 35.9%, respectively). A total of 48 isolates (75%) showed phenotypic resistance to at least 1 antibiotic determined by a disk-diffusion method, and 25 isolates (39.1%) harbored at least 1 antibiotic resistance gene [erm(B), tet(M), tet(S), tet(K), tet(L), tet(T), vanC2, and aad(E)], detected by PCR. One (1.6%) isolate produced gelatinase and none produced hemolysin, using a plate assay. The virulence genes gelE (46.9%), efaAfs (17.2%), agg (1.6%), and hyl (1.6%) were detected by PCR. A total of 48 isolates (75%) exerted antimicrobial activity against 1 or more of the tested fish pathogens, using a stab-on-agar test. From these isolates, 21 (43.8%) harbored at least 1 bacteriocin-encoding gene (entP, entL50A and entL50B, hirJM79, entSE-K4, entQ and entA), detected by PCR. None of the enterococci showed bile deconjugation and mucin degradation abilities. A total of 17 enterococcal isolates (26.6%) that did not harbor any antibiotic resistance or virulence factor were considered safe for application as probiotics, including 6 isolates (35.3%) that showed antimicrobial activity against at least 1 fish pathogen and harbored at least 1 bacteriocin-encoding gene. Rainbow trout, feed, and rearing environment constitute an appropriate source for the

  16. Evaluation of Enterococcus spp. from rainbow trout (Oncorhynchus mykiss, Walbaum), feed, and rearing environment against fish pathogens.

    PubMed

    Araújo, Carlos; Muñoz-Atienza, Estefanía; Hernández, Pablo E; Herranz, Carmen; Cintas, Luis M; Igrejas, Gilberto; Poeta, Patrícia

    2015-04-01

    The use of lactic acid bacteria of aquatic origin as probiotics constitutes an alternative strategy to the antibiotic treatment for disease control in aquaculture. Enterococci are currently used as probiotics in human and animal health. In this study, we evaluated the safety of 64 enterococci isolated from rainbow trout (Oncorhynchus mykiss, Walbaum), feed and rearing environment, and their antimicrobial activity against 9 fish pathogens. The 64 enterococcal isolates were identified to the species level by polymerase chain reaction (PCR), using specific primers for the different enterococcal species, and confirmed by superoxide dismutase gene sequencing. Enterococcus faecium and E. hirae were the most common species (42.2 and 35.9%, respectively). A total of 48 isolates (75%) showed phenotypic resistance to at least 1 antibiotic determined by a disk-diffusion method, and 25 isolates (39.1%) harbored at least 1 antibiotic resistance gene [erm(B), tet(M), tet(S), tet(K), tet(L), tet(T), vanC2, and aad(E)], detected by PCR. One (1.6%) isolate produced gelatinase and none produced hemolysin, using a plate assay. The virulence genes gelE (46.9%), efaAfs (17.2%), agg (1.6%), and hyl (1.6%) were detected by PCR. A total of 48 isolates (75%) exerted antimicrobial activity against 1 or more of the tested fish pathogens, using a stab-on-agar test. From these isolates, 21 (43.8%) harbored at least 1 bacteriocin-encoding gene (entP, entL50A and entL50B, hirJM79, entSE-K4, entQ and entA), detected by PCR. None of the enterococci showed bile deconjugation and mucin degradation abilities. A total of 17 enterococcal isolates (26.6%) that did not harbor any antibiotic resistance or virulence factor were considered safe for application as probiotics, including 6 isolates (35.3%) that showed antimicrobial activity against at least 1 fish pathogen and harbored at least 1 bacteriocin-encoding gene. Rainbow trout, feed, and rearing environment constitute an appropriate source for the

  17. Feeding Ecology of Predatory Fishes from Groote Eylandt in the Gulf of Carpentaria, Australia, with Special Reference to Predation on Penaeid Prawns

    NASA Astrophysics Data System (ADS)

    Brewer, D. T.; Blaber, S. J. M.; Salini, J. P.; Farmer, M. J.

    1995-05-01

    The aim of this study was to describe the feeding ecology of predatory fishes in the inshore waters of Groote Eylandt in the Gulf of Carpentaria, a large tropical bay in northern Australia. This knowledge will increase our understanding of trophic ecology of fishes in tropical waters and, in particular, their interactions with commercially important penaeid prawns. Several structurally complex habitats, including seagrass beds, mixed seagrass/reef habitats and mangrove areas, which support a diverse marine fauna, are found in these shallow waters. Consequently the diets of most predatory fishes in the region comprise a wide variety of fish and invertebrate prey. Juveniles of several species of penaeid live in seagrasses, where they are preyed on by, especially, Scomberoides commersonianusand the common shark species. However, the impact on juvenile penaeid populations is not as high as in the tropical estuaries of north-eastern Australia where fish abundances are lower. Many predatory fishes are size-selective and, in general, larger fish eat bigger penaeids. Seasonal and diel predation on penaeids is largely density-dependent. Evidence from this and previous studies indicates that individual species of tropical marine fishes eat similar prey (taxa and proportions) regardless of their habitat; any differences are chiefly only at the level of genus or species.

  18. Practical aspects of oronasopharyngeal suction in children.

    PubMed

    Knox, Tony

    2011-09-01

    Undergoing oronasopharyngeal suction is an unpleasant experience, but the intervention may prevent the deterioration of children who cannot clear their secretions. A successful procedure requires a practitioner with appropriate knowledge, dexterity and communication skills. Thorough training should be provided and a careful risk-benefit assessment is important before suction is performed.

  19. Feed of Siamese fighting fish, Betta splendens, (Regan, 1910) in open pond: live and formulated diets.

    PubMed

    Sipaúba-Tavares, L H; Appoloni, A M; Fernandes, J B K; Millan, R N

    2016-06-01

    The growth rate and percent survival of Betta splendens when submitted to formulated diet and live food treatments are evaluated. The three different diets were used and designated as: formulated diet (basal diet); live food diet (plankton) and mixed diet (formulated diet with plankton). The live food diet contained plankton belonging to an open pond. High mortality was reported with live food (plankton) treatment whereas higher percent survival occurred with formulated diet. Highest specific growth rate, weight gain and final weight were reported in the mixed diet treatment and were significantly different (p<0.01) from those in formulated diet and live food treatments. The gut contents of B. splendens in mixed diet and live food treatments comprised, Rotifera and Bacillariophyceae species in high percentages or rather, over 78% of total organisms. Lecane sp. was the most ingested zooplankton species by B. splendens in both treatments (mixed diet and live food), with the phytoplankton species Asterionella sp. and Melosira sp. respectively in mixed diet and in live food, respectively. Results indicated that the formulated diet influenced the water parameters dissolved oxygen, total suspended solids, total dissolved solids and pH. The live food in the open pond was not enough to improve the growth rate and percent survival of B. splendens. The growth performance of B. splendens; had the best results with mixed diet which was capable of maintaining species's survival (82%) and development in artificial conditions, benefiting the culture management of ornamental fish.

  20. Feed of Siamese fighting fish, Betta splendens, (Regan, 1910) in open pond: live and formulated diets.

    PubMed

    Sipaúba-Tavares, L H; Appoloni, A M; Fernandes, J B K; Millan, R N

    2016-06-01

    The growth rate and percent survival of Betta splendens when submitted to formulated diet and live food treatments are evaluated. The three different diets were used and designated as: formulated diet (basal diet); live food diet (plankton) and mixed diet (formulated diet with plankton). The live food diet contained plankton belonging to an open pond. High mortality was reported with live food (plankton) treatment whereas higher percent survival occurred with formulated diet. Highest specific growth rate, weight gain and final weight were reported in the mixed diet treatment and were significantly different (p<0.01) from those in formulated diet and live food treatments. The gut contents of B. splendens in mixed diet and live food treatments comprised, Rotifera and Bacillariophyceae species in high percentages or rather, over 78% of total organisms. Lecane sp. was the most ingested zooplankton species by B. splendens in both treatments (mixed diet and live food), with the phytoplankton species Asterionella sp. and Melosira sp. respectively in mixed diet and in live food, respectively. Results indicated that the formulated diet influenced the water parameters dissolved oxygen, total suspended solids, total dissolved solids and pH. The live food in the open pond was not enough to improve the growth rate and percent survival of B. splendens. The growth performance of B. splendens; had the best results with mixed diet which was capable of maintaining species's survival (82%) and development in artificial conditions, benefiting the culture management of ornamental fish. PMID:27097088

  1. Between-Habitat Variation of Benthic Cover, Reef Fish Assemblage and Feeding Pressure on the Benthos at the Only Atoll in South Atlantic: Rocas Atoll, NE Brazil

    PubMed Central

    Longo, G. O.; Morais, R. A.; Martins, C. D. L.; Mendes, T. C.; Aued, A. W.; Cândido, D. V.; de Oliveira, J. C.; Nunes, L. T.; Fontoura, L.; Sissini, M. N.; Teschima, M. M.; Silva, M. B.; Ramlov, F.; Gouvea, L. P.; Ferreira, C. E. L.; Segal, B.; Horta, P. A.; Floeter, S. R.

    2015-01-01

    The Southwestern Atlantic harbors unique and relatively understudied reef systems, including the only atoll in South Atlantic: Rocas atoll. Located 230 km off the NE Brazilian coast, Rocas is formed by coralline red algae and vermetid mollusks, and is potentially one of the most “pristine” areas in Southwestern Atlantic. We provide the first comprehensive and integrative description of the fish and benthic communities inhabiting different shallow reef habitats of Rocas. We studied two contrasting tide pool habitats: open pools, which communicate with the open ocean even during low tides, thus more exposed to wave action; and closed pools, which remain isolated during low tide and are comparatively less exposed. Reef fish assemblages, benthic cover, algal turfs and fish feeding pressure on the benthos remarkably varied between open and closed pools. The planktivore Thalassoma noronhanum was the most abundant fish species in both habitats. In terms of biomass, the lemon shark Negaprion brevirostris and the omnivore Melichtys niger were dominant in open pools, while herbivorous fishes (mainly Acanthurus spp.) prevailed in closed pools. Overall benthic cover was dominated by algal turfs, composed of articulated calcareous algae in open pools and non-calcified algae in closed pools. Feeding pressure was dominated by acanthurids and was 10-fold lower in open pools than in closed pools. Besides different wave exposure conditions, such pattern could also be related to the presence of sharks in open pools, prompting herbivorous fish to feed more in closed pools. This might indirectly affect the structure of reef fish assemblages and benthic communities. The macroalgae Digenea simplex, which is uncommon in closed pools and abundant in the reef flat, was highly preferred in herbivory assays, indicating that herbivory by fishes might be shaping this distribution pattern. The variations in benthic and reef fish communities, and feeding pressure on the benthos between open

  2. Between-Habitat Variation of Benthic Cover, Reef Fish Assemblage and Feeding Pressure on the Benthos at the Only Atoll in South Atlantic: Rocas Atoll, NE Brazil.

    PubMed

    Longo, G O; Morais, R A; Martins, C D L; Mendes, T C; Aued, A W; Cândido, D V; de Oliveira, J C; Nunes, L T; Fontoura, L; Sissini, M N; Teschima, M M; Silva, M B; Ramlov, F; Gouvea, L P; Ferreira, C E L; Segal, B; Horta, P A; Floeter, S R

    2015-01-01

    The Southwestern Atlantic harbors unique and relatively understudied reef systems, including the only atoll in South Atlantic: Rocas atoll. Located 230 km off the NE Brazilian coast, Rocas is formed by coralline red algae and vermetid mollusks, and is potentially one of the most "pristine" areas in Southwestern Atlantic. We provide the first comprehensive and integrative description of the fish and benthic communities inhabiting different shallow reef habitats of Rocas. We studied two contrasting tide pool habitats: open pools, which communicate with the open ocean even during low tides, thus more exposed to wave action; and closed pools, which remain isolated during low tide and are comparatively less exposed. Reef fish assemblages, benthic cover, algal turfs and fish feeding pressure on the benthos remarkably varied between open and closed pools. The planktivore Thalassoma noronhanum was the most abundant fish species in both habitats. In terms of biomass, the lemon shark Negaprion brevirostris and the omnivore Melichtys niger were dominant in open pools, while herbivorous fishes (mainly Acanthurus spp.) prevailed in closed pools. Overall benthic cover was dominated by algal turfs, composed of articulated calcareous algae in open pools and non-calcified algae in closed pools. Feeding pressure was dominated by acanthurids and was 10-fold lower in open pools than in closed pools. Besides different wave exposure conditions, such pattern could also be related to the presence of sharks in open pools, prompting herbivorous fish to feed more in closed pools. This might indirectly affect the structure of reef fish assemblages and benthic communities. The macroalgae Digenea simplex, which is uncommon in closed pools and abundant in the reef flat, was highly preferred in herbivory assays, indicating that herbivory by fishes might be shaping this distribution pattern. The variations in benthic and reef fish communities, and feeding pressure on the benthos between open and

  3. Between-Habitat Variation of Benthic Cover, Reef Fish Assemblage and Feeding Pressure on the Benthos at the Only Atoll in South Atlantic: Rocas Atoll, NE Brazil.

    PubMed

    Longo, G O; Morais, R A; Martins, C D L; Mendes, T C; Aued, A W; Cândido, D V; de Oliveira, J C; Nunes, L T; Fontoura, L; Sissini, M N; Teschima, M M; Silva, M B; Ramlov, F; Gouvea, L P; Ferreira, C E L; Segal, B; Horta, P A; Floeter, S R

    2015-01-01

    The Southwestern Atlantic harbors unique and relatively understudied reef systems, including the only atoll in South Atlantic: Rocas atoll. Located 230 km off the NE Brazilian coast, Rocas is formed by coralline red algae and vermetid mollusks, and is potentially one of the most "pristine" areas in Southwestern Atlantic. We provide the first comprehensive and integrative description of the fish and benthic communities inhabiting different shallow reef habitats of Rocas. We studied two contrasting tide pool habitats: open pools, which communicate with the open ocean even during low tides, thus more exposed to wave action; and closed pools, which remain isolated during low tide and are comparatively less exposed. Reef fish assemblages, benthic cover, algal turfs and fish feeding pressure on the benthos remarkably varied between open and closed pools. The planktivore Thalassoma noronhanum was the most abundant fish species in both habitats. In terms of biomass, the lemon shark Negaprion brevirostris and the omnivore Melichtys niger were dominant in open pools, while herbivorous fishes (mainly Acanthurus spp.) prevailed in closed pools. Overall benthic cover was dominated by algal turfs, composed of articulated calcareous algae in open pools and non-calcified algae in closed pools. Feeding pressure was dominated by acanthurids and was 10-fold lower in open pools than in closed pools. Besides different wave exposure conditions, such pattern could also be related to the presence of sharks in open pools, prompting herbivorous fish to feed more in closed pools. This might indirectly affect the structure of reef fish assemblages and benthic communities. The macroalgae Digenea simplex, which is uncommon in closed pools and abundant in the reef flat, was highly preferred in herbivory assays, indicating that herbivory by fishes might be shaping this distribution pattern. The variations in benthic and reef fish communities, and feeding pressure on the benthos between open and

  4. Development of thiamine deficiencies and early mortality syndrome in lake trout by feeding experimental and feral fish diets containing thiaminase

    USGS Publications Warehouse

    Honeyfield, D.C.; Hinterkopf, J.P.; Fitzsimons, J.D.; Tillitt, D.E.; Zajicek, J.L.; Brown, S.B.

    2005-01-01

    We conducted a laboratory investigation on the consequences of feeding predatory saimonids either experimental diets low in thiamine or diets containing alewife Alosa pseudoharengus. In experiment 1, adult lake trout Salvelinus namaycush were fed experimental diets containing bacterial thiaminase. In experiment 2, adult lake trout were fed natural prey species, alewives, and bloaters Coregonus hoyi. The diets consisted of four combinations of alewives and bloaters from Lake Michigan (100% alewives, 65% alewives-35% bloaters, 35% alewives-65% bloaters, and 100% bloaters), alewives from Cayuga Lake, a casein bacterial thiaminase, and a commercial trout diet. We assessed the effects of each diet on egg thiamine concentration and incidence of an embryonic early mortality syndrome (EMS). In experiment 1, incidence of EMS ranged from 0% to 100%. Significant relationships were found between the incidence of EMS and thiamine. In experiment 2, adult lake trout fed 100% alewives from either Lake Michigan or Cayuga Lake or fish fed the casein bacterial thiaminase diet produced eggs with low thiamine and swim-up fry with EMS. At either 35% or 65% alewives in the diet, egg thiamine was significantly lowered. The number of females that produced offspring that died from EMS were low but demonstrated the negative potential if feral lake trout foraged on either 35% or 65% alewives. Depleted egg thiamine and the onset of EMS required diets containing thiaminase for a minimum of 2 years in lake trout initially fully thiamine replete. We conclude that EMS can be caused by extensive feeding on 100% alewives and dietary levels of 35% or greater may prove detrimental to sustainable reproduction of salmonids in the Great Lakes. The data are consistent with that observed in feral lake trout, and it is concluded that EMS is the result of a thiamine deficiency. ?? Copyright by the American Fisheries Society 2005.

  5. Elemental content of commercial 'ready to-feed' poultry and fish based infant foods in the UK.

    PubMed

    Zand, Nazanin; Chowdhry, Babur Z; Wray, David S; Pullen, Frank S; Snowden, Martin J

    2012-12-15

    The study reported herein was conducted in order to establish the concentration of 20 essential and non-essential elements in a representative range of commercial infant foods in the UK targeted for infants aged between 6-12 months. The primary objective of this study was to examine the nutritive values and safety of such complementary infant foods on the UK market in relation to dietary and safety guidelines. Quantitative analyses were conducted on eight different products representing four popular brands (poultry and fish based) of ready to-feed infant foods currently on sale in the UK. Six essential elements, namely: calcium, iron, magnesium, potassium, sodium and zinc were determined by ICP-OES. The concentrations of six essential trace elements (selenium, molybdenum, cobalt, copper, chromium, manganese) and eight non-essential, potentially toxic, elements (arsenic, barium, nickel, cadmium, antimony, lead, mercury, aluminium) were determined by ICP-MS due to the higher sensitivity required. The total daily intakes of essential and trace elements from the consumption of such products were then estimated, based on the results of this study, and were referenced to the Recommended Nutrient Intake (RNI) values and safety guidelines for 6-9 months old children. Based on these comparisons the concentration of essential, except for potassium, and trace elements were found to be inadequate in meeting the RNI. In terms of the risk of exposure to toxicity, the concentration of toxic elements in ready to feed products analysed in this study, were not considered to be of concern. These results suggest that commercial complementary infant foods on the UK market may not contain minimum levels of minerals required for labelling declaration of micronutrient content (Commission Directive 2006/125/EC). This provides opportunities and scope for product optimisation to improve their nutritive value. PMID:22980874

  6. Effects of flooding regime on the feeding activity and body condition of piscivorous fish in the Upper Paraná River floodplain.

    PubMed

    Luz-Agostinho, K D G; Agostinho, A A; Gomes, L C; Júlio, H F; Fugi, R

    2009-06-01

    Flood pulses affect floodplain enrichment via the incorporation of nutrients and terrestrial biomass. As a result, they positively affect the body condition of aquatic organisms. This paper evaluates whether the absence of floods (resulting from dam control) affects the feeding activity and body condition of piscivorous fish. In addition, whether piscivores respond similarly to alterations in the flooding regime was assessed. Five piscivorous species were selected (Acestrorhynchus lacustris, Hoplias aff. malabaricus, Plagioscion squamosissimus, Rhaphiodon vulpinus, and Salminus brasiliensis). The fish were captured in four distinct years and in three river subsystems with differentiated water level fluctuations (Ivinheira = not regulated; Baía = regulated by the Paraná River level; Paraná = regulated by dams). Feeding activity and body condition were evaluated using the mean values of the standard residuals generated by regression models between body and stomach weights and standard length and body weight (all log-transformed). Differences among years and subsystems were evaluated via two-way analysis of variance. Pearson and Spearman correlations were performed between flooding attributes (duration, amplitude, timing, and daily variability) and feeding activity and body condition. Feeding activity differed across subsystems, whereas body condition varied across years, depending on the subsystem. Hoplias aff malabaricus (an ambusher adapted to starvation) presented feeding activity independent of the flooding regime and also presented better body condition in times of high water levels. Rhaphidon vulpinus exhibited variations in feeding activity but did not present alterations in body condition. The other species presented poorer body condition in years or subsystems with regular floods. Correlations identified that the duration and timing of floods had negative effects on body condition, whereas amplitude and mean annual water level improved feeding activity

  7. Nano-Fe as feed additive improves the hematological and immunological parameters of fish, Labeo rohita H.

    NASA Astrophysics Data System (ADS)

    Behera, T.; Swain, P.; Rangacharulu, P. V.; Samanta, M.

    2014-08-01

    An experiment was conducted to compare the effects of iron oxide nanoparticles ( T 1) and ferrous sulfate ( T 2) on Indian major carp, Labeo rohita H. There were significant differences ( P < 0.05) in the final weight of T 1 and T 2 compared with the control. Survival rates were not affected by the dietary treatments. Fish fed a basal diet (control) showed lower ( P < 0.05) iron content in muscle compared to T 1 and T 2. Furthermore, the highest value ( P < 0.05) of iron content was observed in T 1. In addition, RBCs and hemoglobin levels were significantly higher in T 1 as compared to other treated groups. Different innate immune parameters such as respiratory burst activity, bactericidal activity and myeloperoxidase activity were higher in nano-Fe-treated diet ( T 1) as compared to other iron source ( T 2) and control in 30 days post-feeding. Moreover, nano-Fe appeared to be more effective ( P < 0.05) than ferrous sulfate in increasing muscle iron and hemoglobin contents. Dietary administration of nano-Fe did not cause any oxidative damage, but improved antioxidant enzymatic activities (SOD and GSH level) irrespective of different iron sources in the basal diet.

  8. Temperature acclimation rate of aerobic scope and feeding metabolism in fishes: implications in a thermally extreme future.

    PubMed

    Sandblom, Erik; Gräns, Albin; Axelsson, Michael; Seth, Henrik

    2014-11-01

    Temperature acclimation may offset the increased energy expenditure (standard metabolic rate, SMR) and reduced scope for activity (aerobic scope, AS) predicted to occur with local and global warming in fishes and other ectotherms. Yet, the time course and mechanisms of this process is little understood. Acclimation dynamics of SMR, maximum metabolic rate, AS and the specific dynamic action of feeding (SDA) were determined in shorthorn sculpin (Myoxocephalus scorpius) after transfer from 10°C to 16°C. SMR increased in the first week by 82% reducing AS to 55% of initial values, while peak postprandial metabolism was initially greater. This meant that the estimated AS during peak SDA approached zero, constraining digestion and leaving little room for additional aerobic processes. After eight weeks at 16°C, SMR was restored, while AS and the estimated AS during peak SDA recovered partly. Collectively, this demonstrated a considerable capacity for metabolic thermal compensation, which should be better incorporated into future models on organismal responses to climate change. A mathematical model based on the empirical data suggested that phenotypes with fast acclimation rates may be favoured by natural selection as the accumulated energetic cost of a slow acclimation rate increases in a warmer future with exacerbated thermal variations. PMID:25232133

  9. Temperature acclimation rate of aerobic scope and feeding metabolism in fishes: implications in a thermally extreme future.

    PubMed

    Sandblom, Erik; Gräns, Albin; Axelsson, Michael; Seth, Henrik

    2014-11-01

    Temperature acclimation may offset the increased energy expenditure (standard metabolic rate, SMR) and reduced scope for activity (aerobic scope, AS) predicted to occur with local and global warming in fishes and other ectotherms. Yet, the time course and mechanisms of this process is little understood. Acclimation dynamics of SMR, maximum metabolic rate, AS and the specific dynamic action of feeding (SDA) were determined in shorthorn sculpin (Myoxocephalus scorpius) after transfer from 10°C to 16°C. SMR increased in the first week by 82% reducing AS to 55% of initial values, while peak postprandial metabolism was initially greater. This meant that the estimated AS during peak SDA approached zero, constraining digestion and leaving little room for additional aerobic processes. After eight weeks at 16°C, SMR was restored, while AS and the estimated AS during peak SDA recovered partly. Collectively, this demonstrated a considerable capacity for metabolic thermal compensation, which should be better incorporated into future models on organismal responses to climate change. A mathematical model based on the empirical data suggested that phenotypes with fast acclimation rates may be favoured by natural selection as the accumulated energetic cost of a slow acclimation rate increases in a warmer future with exacerbated thermal variations.

  10. You are what you eat: diet-induced chemical crypsis in a coral-feeding reef fish

    PubMed Central

    Brooker, Rohan M.; Munday, Philip L.; Chivers, Douglas P.; Jones, Geoffrey P.

    2015-01-01

    The vast majority of research into the mechanisms of camouflage has focused on forms that confound visual perception. However, many organisms primarily interact with their surroundings using chemosensory systems and may have evolved mechanisms to ‘blend in’ with chemical components of their habitat. One potential mechanism is ‘chemical crypsis' via the sequestration of dietary elements, causing a consumer's odour to chemically match that of its prey. Here, we test the potential for chemical crypsis in the coral-feeding filefish, Oxymonacanthus longirostris, by examining olfactory discrimination in obligate coral-dwelling crabs and a predatory cod. The crabs, which inhabit the corals consumed by O. longirostris, were used as a bioassay to determine the effect of coral diet on fish odour. Crabs preferred the odour of filefish fed their preferred coral over the odour of filefish fed a non-preferred coral, suggesting coral-specific dietary elements that influence odour are sequestered. Crabs also exhibited a similar preference for the odour of filefish fed their preferred coral and odour directly from that coral, suggesting a close chemical match. In behavioural trials, predatory cod were less attracted to filefish odour when presented alongside the coral it had been fed on, suggesting diet can reduce detectability. This is, we believe, the first evidence of diet-induced chemical crypsis in a vertebrate. PMID:25621328

  11. FAST Real Time PCR for control of intra-species recycling in aquaculture feed, focused to the most relevant fish species farmed in Europe.

    PubMed

    Espiñeira, Montserrat; Vieites, Juan M

    2016-08-01

    Recent regulations in animal feed composition prohibit intra-species recycling, the recycling of one given animal species to the same species, in order to avoid potential safety risks to human and animal health. These regulations have generated the need of their control in aquaculture by effective and specific analytical techniques. To date, most studies of species identification and detection in feedstuffs are focused on land species, but few studies are focused on species composition in fish feed. The present work describes five methodologies based in Real Time PCR for detection of the most relevant fish species farmed in Europe: gilthead sea bream (Sparus aurata); sea bass (Dicentrarchus labrax); turbot (Scophthalmus maximus); rainbow trout (Onchorynchus mykiss); and salmon (Salmo salar), in order to guarantee the intra-species recycling regulation in aquaculture feedstuffs.

  12. FAST Real Time PCR for control of intra-species recycling in aquaculture feed, focused to the most relevant fish species farmed in Europe.

    PubMed

    Espiñeira, Montserrat; Vieites, Juan M

    2016-08-01

    Recent regulations in animal feed composition prohibit intra-species recycling, the recycling of one given animal species to the same species, in order to avoid potential safety risks to human and animal health. These regulations have generated the need of their control in aquaculture by effective and specific analytical techniques. To date, most studies of species identification and detection in feedstuffs are focused on land species, but few studies are focused on species composition in fish feed. The present work describes five methodologies based in Real Time PCR for detection of the most relevant fish species farmed in Europe: gilthead sea bream (Sparus aurata); sea bass (Dicentrarchus labrax); turbot (Scophthalmus maximus); rainbow trout (Onchorynchus mykiss); and salmon (Salmo salar), in order to guarantee the intra-species recycling regulation in aquaculture feedstuffs. PMID:26988512

  13. Feeding a Modified Fish Diet to Bottlenose Dolphins Leads to an Increase in Serum Adiponectin and Sphingolipids.

    PubMed

    Sobolesky, Philip M; Harrell, Tyler S; Parry, Celeste; Venn-Watson, Stephanie; Janech, Michael G

    2016-01-01

    Feeding a modified fish diet has been suggested to improve insulin sensitivity in bottlenose dolphins; however, insulin sensitivity was not directly measured. Since demonstrating an improvement in insulin sensitivity is technically difficult in dolphins, we postulated that directional changes in the hormone axis: fibroblast growth factor 21 (FGF21)/Adiponectin/Ceramide (Cer), could provide further support to this hypothesis. We measured 2-h post-prandial serum FGF21, total adiponectin, percent unmodified adiponectin, ceramide, and sphingosine levels from dolphins fed a diet rich in heptadecanoic acid (C17:0) over 24 weeks. Serum FGF21 was quantified by ELISA with an observed range of 129-1599 pg/ml, but did not significantly change over the 24-week study period. Total adiponectin levels (mean ± SD) significantly increased from 776 ± 400 pmol/ml at week 0 to 1196 ± 467 pmol/ml at week 24. The percent unmodified adiponectin levels (mean ± SD) decreased from 23.8 ± 6.0% at week 0 to 15.2 ± 5.2% at week 24. Interestingly, although FGF21 levels did not change, there was a good correlation between FGF21 and total adiponectin (ρ = 0.788, P < 0.001). We quantified the abundances of serum ceramides and sphingosines (SPH) because adiponectin has a defined role in sphingolipid metabolism through adiponectin receptor-mediated activation of ceramidases. The most abundant ceramide in dolphin sera was Cer 24:1 comprising 49% of the ceramides measured. Significant reductions were observed in the unsaturated Cer 18:1, Cer 20:1, and Cer 24:1, whereas significant increases were observed in saturated Cer 22:0, Cer 24:0, and Cer 26:0. However, total serum ceramides did not change. Significant elevations were detected for total sphingosine, dihydrosphingosine, sphingosine-1-phosphate, and dihydrosphingosine-1-phosphate. Proteomic analysis of the serum proteins revealed few changes in serum proteins over the study period. In conclusion

  14. Feeding a Modified Fish Diet to Bottlenose Dolphins Leads to an Increase in Serum Adiponectin and Sphingolipids.

    PubMed

    Sobolesky, Philip M; Harrell, Tyler S; Parry, Celeste; Venn-Watson, Stephanie; Janech, Michael G

    2016-01-01

    Feeding a modified fish diet has been suggested to improve insulin sensitivity in bottlenose dolphins; however, insulin sensitivity was not directly measured. Since demonstrating an improvement in insulin sensitivity is technically difficult in dolphins, we postulated that directional changes in the hormone axis: fibroblast growth factor 21 (FGF21)/Adiponectin/Ceramide (Cer), could provide further support to this hypothesis. We measured 2-h post-prandial serum FGF21, total adiponectin, percent unmodified adiponectin, ceramide, and sphingosine levels from dolphins fed a diet rich in heptadecanoic acid (C17:0) over 24 weeks. Serum FGF21 was quantified by ELISA with an observed range of 129-1599 pg/ml, but did not significantly change over the 24-week study period. Total adiponectin levels (mean ± SD) significantly increased from 776 ± 400 pmol/ml at week 0 to 1196 ± 467 pmol/ml at week 24. The percent unmodified adiponectin levels (mean ± SD) decreased from 23.8 ± 6.0% at week 0 to 15.2 ± 5.2% at week 24. Interestingly, although FGF21 levels did not change, there was a good correlation between FGF21 and total adiponectin (ρ = 0.788, P < 0.001). We quantified the abundances of serum ceramides and sphingosines (SPH) because adiponectin has a defined role in sphingolipid metabolism through adiponectin receptor-mediated activation of ceramidases. The most abundant ceramide in dolphin sera was Cer 24:1 comprising 49% of the ceramides measured. Significant reductions were observed in the unsaturated Cer 18:1, Cer 20:1, and Cer 24:1, whereas significant increases were observed in saturated Cer 22:0, Cer 24:0, and Cer 26:0. However, total serum ceramides did not change. Significant elevations were detected for total sphingosine, dihydrosphingosine, sphingosine-1-phosphate, and dihydrosphingosine-1-phosphate. Proteomic analysis of the serum proteins revealed few changes in serum proteins over the study period. In conclusion

  15. Feeding a Modified Fish Diet to Bottlenose Dolphins Leads to an Increase in Serum Adiponectin and Sphingolipids

    PubMed Central

    Sobolesky, Philip M.; Harrell, Tyler S.; Parry, Celeste; Venn-Watson, Stephanie; Janech, Michael G.

    2016-01-01

    Feeding a modified fish diet has been suggested to improve insulin sensitivity in bottlenose dolphins; however, insulin sensitivity was not directly measured. Since demonstrating an improvement in insulin sensitivity is technically difficult in dolphins, we postulated that directional changes in the hormone axis: fibroblast growth factor 21 (FGF21)/Adiponectin/Ceramide (Cer), could provide further support to this hypothesis. We measured 2-h post-prandial serum FGF21, total adiponectin, percent unmodified adiponectin, ceramide, and sphingosine levels from dolphins fed a diet rich in heptadecanoic acid (C17:0) over 24 weeks. Serum FGF21 was quantified by ELISA with an observed range of 129–1599 pg/ml, but did not significantly change over the 24-week study period. Total adiponectin levels (mean ± SD) significantly increased from 776 ± 400 pmol/ml at week 0 to 1196 ± 467 pmol/ml at week 24. The percent unmodified adiponectin levels (mean ± SD) decreased from 23.8 ± 6.0% at week 0 to 15.2 ± 5.2% at week 24. Interestingly, although FGF21 levels did not change, there was a good correlation between FGF21 and total adiponectin (ρ = 0.788, P < 0.001). We quantified the abundances of serum ceramides and sphingosines (SPH) because adiponectin has a defined role in sphingolipid metabolism through adiponectin receptor-mediated activation of ceramidases. The most abundant ceramide in dolphin sera was Cer 24:1 comprising 49% of the ceramides measured. Significant reductions were observed in the unsaturated Cer 18:1, Cer 20:1, and Cer 24:1, whereas significant increases were observed in saturated Cer 22:0, Cer 24:0, and Cer 26:0. However, total serum ceramides did not change. Significant elevations were detected for total sphingosine, dihydrosphingosine, sphingosine-1-phosphate, and dihydrosphingosine-1-phosphate. Proteomic analysis of the serum proteins revealed few changes in serum proteins over the study period. In conclusion

  16. Evolutionary novelty versus exaptation: oral kinematics in feeding versus climbing in the waterfall-climbing Hawaiian Goby Sicyopterus stimpsoni.

    PubMed

    Cullen, Joshua A; Maie, Takashi; Schoenfuss, Heiko L; Blob, Richard W

    2013-01-01

    Species exposed to extreme environments often exhibit distinctive traits that help meet the demands of such habitats. Such traits could evolve independently, but under intense selective pressures of extreme environments some existing structures or behaviors might be coopted to meet specialized demands, evolving via the process of exaptation. We evaluated the potential for exaptation to have operated in the evolution of novel behaviors of the waterfall-climbing gobiid fish genus Sicyopterus. These fish use an "inching" behavior to climb waterfalls, in which an oral sucker is cyclically protruded and attached to the climbing surface. They also exhibit a distinctive feeding behavior, in which the premaxilla is cyclically protruded to scrape diatoms from the substrate. Given the similarity of these patterns, we hypothesized that one might have been coopted from the other. To evaluate this, we filmed climbing and feeding in Sicyopterus stimpsoni from Hawai'i, and measured oral kinematics for two comparisons. First, we compared feeding kinematics of S. stimpsoni with those for two suction feeding gobiids (Awaous guamensis and Lentipes concolor), assessing what novel jaw movements were required for algal grazing. Second, we quantified the similarity of oral kinematics between feeding and climbing in S. stimpsoni, evaluating the potential for either to represent an exaptation from the other. Premaxillary movements showed the greatest differences between scraping and suction feeding taxa. Between feeding and climbing, overall profiles of oral kinematics matched closely for most variables in S. stimpsoni, with only a few showing significant differences in maximum values. Although current data cannot resolve whether oral movements for climbing were coopted from feeding, or feeding movements coopted from climbing, similarities between feeding and climbing kinematics in S. stimpsoni are consistent with evidence of exaptation, with modifications, between these behaviors. Such

  17. Evolutionary novelty versus exaptation: oral kinematics in feeding versus climbing in the waterfall-climbing Hawaiian Goby Sicyopterus stimpsoni.

    PubMed

    Cullen, Joshua A; Maie, Takashi; Schoenfuss, Heiko L; Blob, Richard W

    2013-01-01

    Species exposed to extreme environments often exhibit distinctive traits that help meet the demands of such habitats. Such traits could evolve independently, but under intense selective pressures of extreme environments some existing structures or behaviors might be coopted to meet specialized demands, evolving via the process of exaptation. We evaluated the potential for exaptation to have operated in the evolution of novel behaviors of the waterfall-climbing gobiid fish genus Sicyopterus. These fish use an "inching" behavior to climb waterfalls, in which an oral sucker is cyclically protruded and attached to the climbing surface. They also exhibit a distinctive feeding behavior, in which the premaxilla is cyclically protruded to scrape diatoms from the substrate. Given the similarity of these patterns, we hypothesized that one might have been coopted from the other. To evaluate this, we filmed climbing and feeding in Sicyopterus stimpsoni from Hawai'i, and measured oral kinematics for two comparisons. First, we compared feeding kinematics of S. stimpsoni with those for two suction feeding gobiids (Awaous guamensis and Lentipes concolor), assessing what novel jaw movements were required for algal grazing. Second, we quantified the similarity of oral kinematics between feeding and climbing in S. stimpsoni, evaluating the potential for either to represent an exaptation from the other. Premaxillary movements showed the greatest differences between scraping and suction feeding taxa. Between feeding and climbing, overall profiles of oral kinematics matched closely for most variables in S. stimpsoni, with only a few showing significant differences in maximum values. Although current data cannot resolve whether oral movements for climbing were coopted from feeding, or feeding movements coopted from climbing, similarities between feeding and climbing kinematics in S. stimpsoni are consistent with evidence of exaptation, with modifications, between these behaviors. Such

  18. [Suction-irrigator device for microsurgery: technical note].

    PubMed

    Gusmão, Sebastião; Silveira, Roberto Leal

    2003-06-01

    A modification of the conventional suction device for microsurgery is described. It consists of a built-in tube in another tube, being the first connected to the suction device and the second to the irrigation. This suction-irrigator device allows to accomplish the suction and irrigation simultaneously and in a precise way. PMID:12806518

  19. Largemouth bass (Micropterus salmoides) switch feeding modalities in response to sensory deprivation.

    PubMed

    Gardiner, Jayne M; Motta, Philip J

    2012-04-01

    Animals use a suite of sensory modalities to precisely locate and capture prey. While numerous studies have examined the effects of sensory deprivation on the behaviors leading to prey capture and while it is generally believed that information in the pre-strike period determines the way fish capture prey, this study is the first to examine the contribution of sensory information to jaw kinematics during capture. Largemouth bass were filmed using high-speed videography while capturing live mosquitofish. Bass were examined intact, with visual deprivation under infrared light, and with lateral line deprivation following treatment with cobalt chloride. Deprived of visual cues, this visual ram-feeding predator switches towards suction-based feeding to successfully capture prey. They approach prey slowly but open their mouths more rapidly, which has been shown to result in greater buccal pressure, causing their prey to move a greater distance at a more rapid velocity as they are being drawn into the predators' mouths. Deprived of lateral line cues, bass have higher forward velocities during capture and capture prey earlier in the gape cycle. This study demonstrates that sensory pre-strike information directly affects the capture modality employed by fishes and that fish can modulate between ram and suction not only by adjusting the amount of ram by increasing or decreasing their movements, but also by actively increasing the amount of suction used. These results suggest that the ability to modulate feeding behavior may allow animals to not only exploit a broader breadth of prey items, but also to be capable of doing so in a wider variety of environments. PMID:22285791

  20. Largemouth bass (Micropterus salmoides) switch feeding modalities in response to sensory deprivation.

    PubMed

    Gardiner, Jayne M; Motta, Philip J

    2012-04-01

    Animals use a suite of sensory modalities to precisely locate and capture prey. While numerous studies have examined the effects of sensory deprivation on the behaviors leading to prey capture and while it is generally believed that information in the pre-strike period determines the way fish capture prey, this study is the first to examine the contribution of sensory information to jaw kinematics during capture. Largemouth bass were filmed using high-speed videography while capturing live mosquitofish. Bass were examined intact, with visual deprivation under infrared light, and with lateral line deprivation following treatment with cobalt chloride. Deprived of visual cues, this visual ram-feeding predator switches towards suction-based feeding to successfully capture prey. They approach prey slowly but open their mouths more rapidly, which has been shown to result in greater buccal pressure, causing their prey to move a greater distance at a more rapid velocity as they are being drawn into the predators' mouths. Deprived of lateral line cues, bass have higher forward velocities during capture and capture prey earlier in the gape cycle. This study demonstrates that sensory pre-strike information directly affects the capture modality employed by fishes and that fish can modulate between ram and suction not only by adjusting the amount of ram by increasing or decreasing their movements, but also by actively increasing the amount of suction used. These results suggest that the ability to modulate feeding behavior may allow animals to not only exploit a broader breadth of prey items, but also to be capable of doing so in a wider variety of environments.

  1. Bio-inspired particle separator design based on the food retention mechanism by suspension-feeding fish.

    PubMed

    Hung, Tien-Chieh; Piedrahita, Raul H; Cheer, Angela

    2012-12-01

    A new particle separator is designed using a crossflow filtration mechanism inspired by suspension-feeding fish in this study. To construct the model of the bio-inspired particle separator, computational fluid dynamics techniques are used, and parameters related to separator shape, fluid flow and particle properties that might affect the performance in removing particles from the flow, are varied and tested. The goal is to induce a flow rotation which enhances the separation of particles from the flow, reduce the particle-laden flow that exits via a collection zone at the lower/posterior end of the separator, while at the same time increase the concentration of particles in that flow. Based on preliminary particle removal efficiency tests, an exiting flow through the collection zone of about 8% of the influent flow rate is selected for all the performance tests of the separator including trials with particles carried by air flow instead of water. Under this condition, the simulation results yield similar particle removal efficiencies in water and air but with different particle properties. Particle removal efficiencies (percentage of influent particles that exit through the collection zone) were determined for particles ranging in size from 1 to 1500 µm with a density between 1000 and 1150 kg m(-3) in water and 2 and 19 mm and 68 and 2150 kg m(-3) in air. As an example, removal efficiencies are 66% and 64% for 707 µm diameter particles with a density of 1040 kg m(-3) in water and for 2 mm particles with a density of 68 kg m(-3) in air, respectively. No significant performance difference is found by geometrically scaling the inlet diameter of the separator up or down in the range from 2.5 to 10 cm.

  2. Effects of Feeding Diets With or Without Fish Meal on Production of Channel Catfish, Ictalurus Punctatus, Stocked at Varying Densities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Animal protein, generally fish meal, has traditionally been used in the diet of channel catfish. However, our previous research indicates that animal protein is not needed for growing stocker size catfish to food fish when the fish are stocked at densities typical of those used in commercial catfish...

  3. Fish oil in feeds for entire male and female pigs: changes in muscle fatty acid composition and stability of sensory quality.

    PubMed

    Hallenstvedt, E; Kjos, N P; Rehnberg, A C; Overland, M; Thomassen, M

    2010-05-01

    A total of 72 crossbred [(Norwegian Landrace x Yorkshire) x Duroc] male and female growing-finishing pigs were restrictedly fed diets containing fish oil to study the fatty acid composition of Musculus longissimusdorsi and sensory quality of belly and neck. Six diets were used: two low-fat diets with or without 0.5% fish oil added, and four medium-fat diets with palm kernel oil to fish oil in ratios given as % inclusion: 4.1:0.0, 3.9:0.3, 3.6:0.5 and 3.4:0.7. Feeding fish oil gave a dose-dependent response between fatty acids in the diets and in the M.longissimusdorsi and increased the level of very long chain n-3 fatty acids, especially the C22:5n-3 (DPA). A more efficient n-3 fatty acids deposition was obtained when given as a medium-fat diet rather than the low-fat diet. Female pigs had a significant higher percentage of monounsaturated fatty acids and C18:1 than males suggesting a gender related difference in the delta-9-desaturase activity. No significant differences were found in sensory attributes for short-term stored neck and belly. For pigs fed the highest level of fish oil (0.7%) long-term stored (12 months at -80 degrees C, 6 months at -20 degrees C) belly showed a slight increase in fish oil flavour. After warmed-over treatment, fish oil odour and flavour as well as rancid flavour were increased in this group. The results suggest levels of dietary fish oil up to 0.5% produce a healthier meat fatty acid composition, without negative effects on sensory attributes, even in long-termed stored belly. PMID:20374883

  4. Fish oil in feeds for entire male and female pigs: changes in muscle fatty acid composition and stability of sensory quality.

    PubMed

    Hallenstvedt, E; Kjos, N P; Rehnberg, A C; Overland, M; Thomassen, M

    2010-05-01

    A total of 72 crossbred [(Norwegian Landrace x Yorkshire) x Duroc] male and female growing-finishing pigs were restrictedly fed diets containing fish oil to study the fatty acid composition of Musculus longissimusdorsi and sensory quality of belly and neck. Six diets were used: two low-fat diets with or without 0.5% fish oil added, and four medium-fat diets with palm kernel oil to fish oil in ratios given as % inclusion: 4.1:0.0, 3.9:0.3, 3.6:0.5 and 3.4:0.7. Feeding fish oil gave a dose-dependent response between fatty acids in the diets and in the M.longissimusdorsi and increased the level of very long chain n-3 fatty acids, especially the C22:5n-3 (DPA). A more efficient n-3 fatty acids deposition was obtained when given as a medium-fat diet rather than the low-fat diet. Female pigs had a significant higher percentage of monounsaturated fatty acids and C18:1 than males suggesting a gender related difference in the delta-9-desaturase activity. No significant differences were found in sensory attributes for short-term stored neck and belly. For pigs fed the highest level of fish oil (0.7%) long-term stored (12 months at -80 degrees C, 6 months at -20 degrees C) belly showed a slight increase in fish oil flavour. After warmed-over treatment, fish oil odour and flavour as well as rancid flavour were increased in this group. The results suggest levels of dietary fish oil up to 0.5% produce a healthier meat fatty acid composition, without negative effects on sensory attributes, even in long-termed stored belly.

  5. [Ultrasonic aspirator with controllable suction system--variable action suction adapter and clinical experience with it].

    PubMed

    Nagasawa, S; Shimano, H; Kuroiwa, T

    2000-12-01

    While the ultrasonic aspirator (UA) has been widely used as one of the indispensable tools in the field of neurosurgery, a potential risk when using the present UA is injury to the neurovascular structures due to ultrasonic pulverization and constant forceful suction power. We have devised a small variable action suction adapter that can be used in a similar manner to conventional surgical suction tubes. The UA control unit and the handpiece used in this study were the Sonopet UST-2000 and HA-01, respectively (M & M Corporation Tokyo, Japan). The handpiece is slim, with the mid-portion diameter of 13 mm, and it weighs 100 grams. A variable action suction adapter was made from polycarbonate of 15 x 12 x 13 mm in size. The adapter was connected to the suction tube using a Y-shaped connector (Fig. 2 A), which was integrated into the handpiece. The suction power is regulated by variably closing the oval-shaped hole. The adapter can be variously placed on and rotated around the handpiece (Fig. 2 B and C) so that either the right or left hand handles it in a similar fashion to conventional suction tubes. We used this UA in surgery for 8 patients with large brain tumors (meningioma in 5 cases, metastatic brain tumor in 2 cases and glioma in one case). It reduced the risk of suction-related injury to the neurovascular structures and was handled in a similar manner to conventional suction tubes. This adapter ensures the complete control of suction power, which will reduce the risk of suction injury.

  6. Comparison of early life-stage strategies in temperate freshwater fish species: trade-offs are directed towards first feeding of larvae in spring and early summer.

    PubMed

    Teletchea, F; Fontaine, P

    2010-07-01

    Based on the analysis of 12 egg and larval variables and temperature of 65 temperate freshwater fish species, the possible relationships between oocyte diameter, larval size at hatch, time and temperature were reassessed and the main early life-stage strategies were described and compared. Time and degree-days required to reach hatching and mixed feeding were weakly related to oocyte diameter and strongly to temperature. These results are chiefly because oocyte diameter and yolk reserves are weakly related and temperature strongly increases tissue differentiation rate, activity of hatching glands and embryo motility. Strong positive relationships were found between larval size and oocyte diameter and degree-days for incubation. No relationship was found between larval size and degree-days from hatching to mixed feeding and between degree-days for incubation and degree-days from hatching to mixed feeding. These last two results are chiefly because the developmental stages at hatching and at the onset of exogenous feeding are not fixed in ontogeny and are not directly related to either larval size or degree-days for incubation, but more probably are species specific. Whatever the spawning season, which can occur almost all year long, the different trade-offs at the early life-stages ensure that most larvae are first feeding during spring, when food size and abundance are the most appropriate.

  7. Detection of feeding behaviour in common carp Cyprinus carpio by using an acceleration data logger to identify mandibular movement.

    PubMed

    Makiguchi, Y; Sugie, Y; Kojima, T; Naito, Y

    2012-05-01

    Miniaturized acceleration data loggers were attached to the lower mandible of common carp Cyprinus carpio to remotely identify feeding behaviour. Whether the acceleration signal could distinguish the quantity and quality of food was also investigated. The frequency and amplitude of the lower mandible stroke, calculated from surging acceleration determined by continuous wavelet transformation, significantly increased during the feeding period compared to that during the non-feeding period. These characteristic movement patterns were maintained for mean ±s.e. 187·3 ± 38·2 s when the fish were fed a single item of food and for mean ±s.e. 419·3 ± 28·6 s when they consumed multiple items. The dominant cycle and amplitude calculated according to feeding event duration, however, did not differ significantly between the two types of diets the fish consumed. Surging acceleration could detect mean ±s.e. 89·8 ± 13·5% of feeding events, although the false detection rate was mean ±s.e. 25·9 ± 10·9%. The results indicate that the mandible acceleration measurement method could be utilized to detect and record the feeding events in fishes that use a suction feeding mode similar to C. carpio.

  8. Detection of feeding behaviour in common carp Cyprinus carpio by using an acceleration data logger to identify mandibular movement.

    PubMed

    Makiguchi, Y; Sugie, Y; Kojima, T; Naito, Y

    2012-05-01

    Miniaturized acceleration data loggers were attached to the lower mandible of common carp Cyprinus carpio to remotely identify feeding behaviour. Whether the acceleration signal could distinguish the quantity and quality of food was also investigated. The frequency and amplitude of the lower mandible stroke, calculated from surging acceleration determined by continuous wavelet transformation, significantly increased during the feeding period compared to that during the non-feeding period. These characteristic movement patterns were maintained for mean ±s.e. 187·3 ± 38·2 s when the fish were fed a single item of food and for mean ±s.e. 419·3 ± 28·6 s when they consumed multiple items. The dominant cycle and amplitude calculated according to feeding event duration, however, did not differ significantly between the two types of diets the fish consumed. Surging acceleration could detect mean ±s.e. 89·8 ± 13·5% of feeding events, although the false detection rate was mean ±s.e. 25·9 ± 10·9%. The results indicate that the mandible acceleration measurement method could be utilized to detect and record the feeding events in fishes that use a suction feeding mode similar to C. carpio. PMID:22551186

  9. Use of food waste as fish feeds: effects of prebiotic fibers (inulin and mannanoligosaccharide) on growth and non-specific immunity of grass carp (Ctenopharyngodon idella).

    PubMed

    Mo, Wing Y; Cheng, Zhang; Choi, Wai M; Lun, Clare H I; Man, Yu B; Wong, James T F; Chen, Xun W; Lau, Stanley C K; Wong, Ming H

    2015-11-01

    The effects of inulin and mannanoligosaccharide (MOS) on the growth performance and non-specific immunity of grass carp were studied. Two doses of prebiotic fiber with 0.2 or 2% of the fibers are being mixed into fish feed pellets. Fish growth as well as selected non-specific immune parameters of grass carp were tested in a feeding trial, which lasted for 8 weeks. Fish was fed at 2.5% body mass per day. INU02, INU2, and MOS2 significantly improved relative weight gain, specific growth rate, protein efficiency ratio, and food conversion ratio of grass carp fed with food waste-based diet. In terms of non-specific immune response, grass carp showed significant improvement in all three tested parameters (total serum immunoglobin, bactericidal activity, and anti-protease activity). Adding 2% of inulin (INU2) into food waste diets seemed to be more preferable than other supplemented experimental diets (INU02, MOS02, MOS2), as it could promote growth of grass carp as well as improving the non-specific immune systems of grass carp.

  10. Feeding of the megamouth shark (Pisces: Lamniformes: Megachasmidae) predicted by its hyoid arch: a biomechanical approach.

    PubMed

    Tomita, Taketeru; Sato, Keiichi; Suda, Kenta; Kawauchi, Junro; Nakaya, Kazuhiro

    2011-05-01

    Studies of the megamouth shark, one of three planktivorous sharks, can provide information about their evolutionary history. Megamouth shark feeding has never been observed in life animals, but two alternative hypotheses on biomechanics suggest either feeding, i.e., ram feeding or suction feeding. In this study, the second moment of area of the ceratohyal cartilages, which is an indicator of the flexural stiffness of the cartilages, is calculated for 21 species of ram- and suction-feeding sharks using computed tomography. The results indicate that suction-feeding sharks have ceratohyal cartilages with a larger second moment of area than ram-feeding sharks. The result also indicates that the ram-suction index, which is an indicator of relative contribution of ram and suction behavior, is also correlated with the second moment of area of the ceratohyal. Considering that large bending stresses are expected to be applied to the ceratohyal cartilage during suction, the larger second moment of area of the ceratohyal of suction-feeding sharks can be interpreted as an adaptation for suction feeding. Based on the small second moment of area of the ceratohyal cartilage of the megamouth shark, the feeding mode of the megamouth shark is considered to be ram feeding, similar to the planktivorous basking shark. From these results, an evolutionary scenario of feeding mechanics of three species of planktivorous sharks can be suggested. In this scenario, the planktivorous whale shark evolved ram feeding from a benthic suction-feeding ancestor. Ram feeding in the planktivorous megamouth shark and the basking shark evolved from ram feeding swimming-type ancestors and that both developed their unique filtering system to capture small-sized prey.

  11. Negative tracheal pressure during neonatal endotracheal suction.

    PubMed

    Kiraly, Nicholas J; Tingay, David G; Mills, John F; Morley, Colin J; Copnell, Beverley

    2008-07-01

    Endotracheal tube (ETT) suction is the most frequently performed invasive procedure in ventilated newborn infants and is associated with adverse effects related to negative tracheal pressure. We aimed to measure suction catheter gas flow and intratracheal pressure during ETT suction of a test lung and develop a mathematical model to predict tracheal pressure from catheter and ETT dimensions and applied pressure. Tracheal pressure and catheter flow were recorded during suction of ETT sizes 2.5-4.0 mm connected to a test lung with catheters 5-8 French Gauge and applied pressures of 80-200 mm Hg. The fraction of applied pressure transmitted to the trachea was calculated for each combination, and data fitted to three nonlinear models for analysis. Tracheal pressure was directly proportional to applied pressure (r = 0.82-0.99), and catheter flow fitted a turbulent flow model (R = 0.85-0.96). With each ETT, increasing catheter size resulted in greater catheter flow (p < 0.0001) and thus lower intratracheal pressure (p < 0.0001). The fraction of applied pressure transmitted to the trachea was accurately modeled using ETT and catheter dimensions (R = 0.98-0.99). Negative tracheal pressure during in vitro ETT suction is directly proportional to applied pressure. This relationship is determined by ETT and catheter dimensions.

  12. Are parasite richness and abundance linked to prey species richness and individual feeding preferences in fish hosts?

    PubMed

    Cirtwill, Alyssa R; Stouffer, Daniel B; Poulin, Robert; Lagrue, Clément

    2016-01-01

    Variations in levels of parasitism among individuals in a population of hosts underpin the importance of parasites as an evolutionary or ecological force. Factors influencing parasite richness (number of parasite species) and load (abundance and biomass) at the individual host level ultimately form the basis of parasite infection patterns. In fish, diet range (number of prey taxa consumed) and prey selectivity (proportion of a particular prey taxon in the diet) have been shown to influence parasite infection levels. However, fish diet is most often characterized at the species or fish population level, thus ignoring variation among conspecific individuals and its potential effects on infection patterns among individuals. Here, we examined parasite infections and stomach contents of New Zealand freshwater fish at the individual level. We tested for potential links between the richness, abundance and biomass of helminth parasites and the diet range and prey selectivity of individual fish hosts. There was no obvious link between individual fish host diet and helminth infection levels. Our results were consistent across multiple fish host and parasite species and contrast with those of earlier studies in which fish diet and parasite infection were linked, hinting at a true disconnect between host diet and measures of parasite infections in our study systems. This absence of relationship between host diet and infection levels may be due to the relatively low richness of freshwater helminth parasites in New Zealand and high host-parasite specificity. PMID:26573385

  13. Are parasite richness and abundance linked to prey species richness and individual feeding preferences in fish hosts?

    PubMed

    Cirtwill, Alyssa R; Stouffer, Daniel B; Poulin, Robert; Lagrue, Clément

    2016-01-01

    Variations in levels of parasitism among individuals in a population of hosts underpin the importance of parasites as an evolutionary or ecological force. Factors influencing parasite richness (number of parasite species) and load (abundance and biomass) at the individual host level ultimately form the basis of parasite infection patterns. In fish, diet range (number of prey taxa consumed) and prey selectivity (proportion of a particular prey taxon in the diet) have been shown to influence parasite infection levels. However, fish diet is most often characterized at the species or fish population level, thus ignoring variation among conspecific individuals and its potential effects on infection patterns among individuals. Here, we examined parasite infections and stomach contents of New Zealand freshwater fish at the individual level. We tested for potential links between the richness, abundance and biomass of helminth parasites and the diet range and prey selectivity of individual fish hosts. There was no obvious link between individual fish host diet and helminth infection levels. Our results were consistent across multiple fish host and parasite species and contrast with those of earlier studies in which fish diet and parasite infection were linked, hinting at a true disconnect between host diet and measures of parasite infections in our study systems. This absence of relationship between host diet and infection levels may be due to the relatively low richness of freshwater helminth parasites in New Zealand and high host-parasite specificity.

  14. Compressible laminar streaks with wall suction

    NASA Astrophysics Data System (ADS)

    Ricco, Pierre; Shah, Daniel; Hicks, Peter D.

    2013-05-01

    The response of a compressible laminar boundary layer subject to free-stream vortical disturbances and steady mean-flow wall suction is studied. The theoretical frameworks of Leib et al. [J. Fluid Mech. 380, 169-203 (1999), 10.1017/S0022112098003504] and Ricco and Wu [J. Fluid Mech. 587, 97-138 (2007), 10.1017/S0022112007007070], based on the linearized unsteady boundary-region equations, are adopted to study the influence of suction on the kinematic and thermal streaks arising through the interaction between the free-stream vortical perturbations and the boundary layer. In the asymptotic limit of small spanwise wavelength compared with the boundary layer thickness, i.e., when the disturbance flow is conveniently described by the steady compressible boundary region equations, the effect of suction is mild on the velocity fluctuations and negligible on the temperature fluctuations. When the spanwise wavelength is comparable with the boundary layer thickness, small suction values intensify the supersonic streaks, while higher transpiration levels always stabilize the disturbances at all Mach numbers. At larger spanwise wavelengths, very small amplitudes of wall transpiration have a dramatic stabilizing effect on all boundary layer fluctuations, which can take the form of transiently growing thermal streaks, large amplitude streamwise oscillations, or oblique exponentially growing Tollmien-Schlichting waves, depending on the Mach number and the wavelengths. The range of wavenumbers for which the exponential growth occurs becomes narrower and the location of instability is significantly shifted downstream by mild suction, indicating that wall transpiration can be a suitable vehicle for delaying transition when the laminar breakdown is promoted by these unstable disturbances. The typical streamwise wavelength of these disturbances is instead not influenced by suction, and asymptotic triple deck theory predicts the strong changes in growth rate and the very mild

  15. Reproduction and Feeding of the Electric Fish Brachyhypopomus gauderio (Gymnotiformes: Hypopomidae) and the Discussion of a Life History Pattern for Gymnotiforms from High Latitudes

    PubMed Central

    Giora, Julia; Tarasconi, Hellen M.; Fialho, Clarice B.

    2014-01-01

    The reproductive biology and feeding habits of the electric fish Brachyhypopomus gauderio were studied. The species has seasonal reproductive behavior, with breeding occurring during the Southern Hemisphere spring and summer, and having a positive relation with the photoperiod variation. Brachyhypopomus gauderio was defined as a fractional spawner, with low relative fecundity and high first maturation size. Sexual dimorphism was registered, males undergoing hypertrophy of the distal portion of caudal filament. The results on reproductive biology herein obtained are in agreement with data concerning gymnotiforms from Southern Brazil and Uruguay, pointing to an ecological pattern for the species from high latitudes, differing from species with tropical distribution. According to the analysis of the food items, B. gauderio feed mainly on autochthonous insects, likewise the other gymnotiforms previously investigated, leading to conclude that there is no variation on the diet of the species of the order related to climatic conditions or even to habitat of occurrence. PMID:25207924

  16. Thermophile-fermented compost as a fish feed additive modulates lipid peroxidation and free amino acid contents in the muscle of the carp, Cyprinus carpio.

    PubMed

    Tanaka, Ryusuke; Miyamoto, Hirokuni; Inoue, Shin-Ichi; Shigeta, Kazuhiro; Kondo, Masakazu; Ito, Toshiyuki; Kodama, Hiroaki; Miyamoto, Hisashi; Matsushita, Teruo

    2016-05-01

    Recently, a compost fermented with marine animals with thermophilic Bacillaceae in a clean and exclusive process at high temperature was reported as a possible feed additive to improve the healthy balance in sea fish and mammals (i.e., pigs and rodents). Here, the effects of the oral administration of the compost on the muscle and internal organs of carp (Cyprinus carpio) as a freshwater fish model were investigated. The fatty acid composition was different in the muscle of the carp fed with or without the compost extract, but there was little difference in the hepatopancreas. The accumulation of triacylglycerols, cholesterol, lipid peroxide and hydroxyl lipids decreased in the muscle after the oral administration of the compost extract in the carps over 12 weeks, but the accumulation did not always decrease in the hepatopancreas. In contrast, free-radical-scavenging activities and the concentrations of free amino acids in the muscle did not always increase and was dependent on the dose of the compost at 12 weeks. The scavenging activities and part of free amino acid levels in the muscle of the carp were improved at 24 weeks after a high dose of compost exposure, and then the survival rates of the carp were maintained. Thus, the oral administration of thermophile-fermented compost can prevent peroxidation and increase the content of free amino acids in the muscle of the freshwater fish, depending on the dose and term of the administration, and may be associated with the viability of the fish.

  17. Confocal microscopy as a useful approach to describe gill rakers of Asian species of carp and native filter-feeding fishes of the upper Mississippi River system.

    PubMed

    Walleser, L R; Howard, D R; Sandheinrich, M B; Gaikowski, M P; Amberg, J J

    2014-11-01

    To better understand potential diet overlap among exotic Asian species of carp and native species of filter-feeding fishes of the upper Mississippi River system, microscopy was used to document morphological differences in the gill rakers. Analysing samples first with light microscopy and subsequently with confocal microscopy, the three-dimensional structure of gill rakers in Hypophthalmichthys molitrix, Hypophthalmichthys nobilis and Dorosoma cepedianum was more thoroughly described and illustrated than previous work with traditional microscopy techniques. The three-dimensional structure of gill rakers in Ictiobus cyprinellus was described and illustrated for the first time.

  18. Confocal microscopy as a useful approach to describe gill rakers of Asian species of carp and native filter-feeding fishes of the upper Mississippi River system

    USGS Publications Warehouse

    Liza R. Walleser,; D.R. Howard,; Sandheinrich, Mark B.; Gaikowski, Mark P.; Amberg, Jon J.

    2014-01-01

    To better understand potential diet overlap among exotic Asian species of carp and native species of filter-feeding fishes of the upper Mississippi River system, microscopy was used to document morphological differences in the gill rakers. Analysing samples first with light microscopy and subsequently with confocal microscopy, the three-dimensional structure of gill rakers in Hypophthalmichthys molitrix,Hypophthalmichthys nobilis and Dorosoma cepedianum was more thoroughly described and illustrated than previous work with traditional microscopy techniques. The three-dimensional structure of gill rakers in Ictiobus cyprinellus was described and illustrated for the first time.

  19. Confocal microscopy as a useful approach to describe gill rakers of Asian species of carp and native filter-feeding fishes of the upper Mississippi River system.

    PubMed

    Walleser, L R; Howard, D R; Sandheinrich, M B; Gaikowski, M P; Amberg, J J

    2014-11-01

    To better understand potential diet overlap among exotic Asian species of carp and native species of filter-feeding fishes of the upper Mississippi River system, microscopy was used to document morphological differences in the gill rakers. Analysing samples first with light microscopy and subsequently with confocal microscopy, the three-dimensional structure of gill rakers in Hypophthalmichthys molitrix, Hypophthalmichthys nobilis and Dorosoma cepedianum was more thoroughly described and illustrated than previous work with traditional microscopy techniques. The three-dimensional structure of gill rakers in Ictiobus cyprinellus was described and illustrated for the first time. PMID:25141916

  20. Remotely operated submersible underwater suction apparatus

    SciTech Connect

    Kristan, Louis L.

    1990-01-01

    A completely submersible, remotely operated underwater suction device for collection of irradiated materials in a nuclear pool is disclosed. The device includes a pump means for pumping water through the device, a filter means for capturing irradiated debris, remotely operated releasable connector means, a collection means and a means for remotely maneuvering the collection means. The components of the suction device may be changed and replaced underwater to take advantage of the excellent radiation shielding ability of water to thereby minimize exposure of personnel to radiation.

  1. Effects of brown fish meal replacement with fermented soybean meal on growth performance, feed efficiency and enzyme activities of Chinese soft-shelled turtle, Pelodiscus sinensis

    NASA Astrophysics Data System (ADS)

    Zou, Yurong; Ai, Qinghui; Mai, Kangsen; Zhang, Wenbing; Zhang, Yanjiao; Xu, Wei

    2012-06-01

    A 120-day feeding experiment was conducted to investigate the effects of partial replacement of brown fish meal (BFM) by fermented soybean meal (FSBM) in diets of Chinese soft-shelled turtle ( Pelodiscus sinensis). The turtles (initial mean body weight, (115.52 ± 1.05) g) were fed with three experimental diets, in which 0%, 4.72% and 9.44% BFM protein was replaced by 0%, 3% and 6% FSBM, respectively. Results showed that the feeding rate (FR), specific growth rate (SGR) and feed efficiency ratio (FER) of turtles fed with the diet containing 3% FSBM were not significantly different from the control group (0% FSBM) ( P > 0.05). However, FR, SGR and FER of turtles fed with the diet containing 6% FSBM were significantly lower than those of the control group ( P < 0.05). No significant differences were observed in the activities of serum glutamic-oxalacetic transaminase and glutamic-pyruvic transaminase among dietary treatments ( P > 0.05). However, the uric acid concentration in turtles fed with the diet containing 3% or 6% FSBM was significantly lower than that in the control group ( P < 0.05). There were no significant differences in the activities of lysozyme, alkaline phosphatase and total superoxide dismutase among dietary treatments ( P > 0.05). The results suggested that FSBM could replace 4.72% BFM protein in turtle diets without exerting adverse effects on turtle growth, feed utilization and measured immune parameters.

  2. Metabolic response to feeding in weight-losing pancreatic cancer patients and its modulation by a fish-oil-enriched nutritional supplement.

    PubMed

    Barber, M D; McMillan, D C; Preston, T; Ross, J A; Fearon, K C

    2000-04-01

    Weight-losing patients with advanced cancer often fail to gain weight with conventional nutritional support. This suboptimal response might be explained, in part, by an increased metabolic response to feeding. It has been suggested that eicosapentaenoic acid (EPA) can modify beneficially the metabolic response to cancer. The aim of the present study was to examine the metabolic response to feeding in cancer and the effects of an EPA-enriched oral food supplement on this response. A total of 16 weight-losing, non-diabetic patients with unresectable pancreatic adenocarcinoma and six healthy, weight-stable controls were studied by indirect calorimetry in the fasting and fed states. Body composition was estimated by bioimpedence analysis. Cancer patients were then given a fish-oil-enriched nutritional supplement providing 2 g of EPA and 2550 kJ daily, and underwent repeat metabolic study after 3 weeks of such supplementation. At baseline, resting energy expenditure whether expressed per kg body weight, lean body mass or body cell mass was significantly greater in the cancer patients compared with controls. Fat oxidation was significantly higher in the fasting state in cancer patients [median 1.26 g.kg(-1).min(-1) (interquartile range 0.95-1.38)] than in controls [0.76 g.kg(-1). min(-1) (0.62-0.92); P<0.05]. Over the 4 h feeding period, changes in insulin and glucose concentrations in cancer patients suggested relative glucose intolerance. In response to oral meal feeding, the percentage change in the area under the curve of energy expenditure was significantly lower in the cancer patients [median 7.9% (interquartile range 3.4-9.0)] than in controls [12.6% (9.9-15.1); P<0.01]. After 3 weeks of the EPA-enriched supplement, the body weight of the cancer patients had increased and the energy expenditure in response to feeding had risen significantly [9.6% (6. 3-12.4)], such that it was no different from baseline healthy control values. Similarly, fasting fat oxidation fell

  3. 21 CFR 884.1175 - Endometrial suction curette and accessories.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... suction curette is a device used to remove material from the uterus and from the mucosal lining of the uterus by scraping and vacuum suction. This device is used to obtain tissue for biopsy or for...

  4. 21 CFR 884.1175 - Endometrial suction curette and accessories.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... suction curette is a device used to remove material from the uterus and from the mucosal lining of the uterus by scraping and vacuum suction. This device is used to obtain tissue for biopsy or for...

  5. 21 CFR 884.1175 - Endometrial suction curette and accessories.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... suction curette is a device used to remove material from the uterus and from the mucosal lining of the uterus by scraping and vacuum suction. This device is used to obtain tissue for biopsy or for...

  6. 21 CFR 884.1175 - Endometrial suction curette and accessories.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... suction curette is a device used to remove material from the uterus and from the mucosal lining of the uterus by scraping and vacuum suction. This device is used to obtain tissue for biopsy or for...

  7. 21 CFR 884.1175 - Endometrial suction curette and accessories.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... suction curette is a device used to remove material from the uterus and from the mucosal lining of the uterus by scraping and vacuum suction. This device is used to obtain tissue for biopsy or for...

  8. Control of voluntary feed intake in fish: a role for dietary oxygen demand in Nile tilapia (Oreochromis niloticus) fed diets with different macronutrient profiles.

    PubMed

    Saravanan, S; Geurden, I; Figueiredo-Silva, A C; Kaushik, S J; Haidar, M N; Verreth, J A J; Schrama, J W

    2012-10-28

    It has been hypothesised that, at non-limiting water oxygen conditions, voluntary feed intake (FI) in fish is limited by the maximal physiological capacity of oxygen use (i.e. an 'oxystatic control of FI in fish'). This implies that fish will adjust FI when fed diets differing in oxygen demand, resulting in identical oxygen consumption. Therefore, FI, digestible energy (DE) intake, energy balance and oxygen consumption were monitored at non-limiting water oxygen conditions in Nile tilapia fed diets with contrasting macronutrient composition. Diets were formulated in a 2 × 2 factorial design in order to create contrasts in oxygen demand: two ratios of digestible protein (DP):DE ('high' v. 'low'); and a contrast in the type of non-protein energy source ('starch' v. 'fat'). Triplicate groups of tilapia were fed each diet twice daily to satiation for 48 d. FI (g DM/kg(0·8) per d) was significantly lower (9·5%) in tilapia fed the starch diets relative to the fat diets. The DP:DE ratio affected DE intakes (P < 0·05), being 11% lower with 'high' than with 'low' DP:DE ratio diets, which was in line with the 11·9% higher oxygen demand of these diets. Indeed, DE intakes of fish showed an inverse linear relationship with dietary oxygen demand (DOD; R 2 0·81, P < 0·001). As hypothesised ('oxystatic' theory), oxygen consumption of fish was identical among three out of the four diets. Altogether, these results demonstrate the involvement of metabolic oxygen use and DOD in the control of FI in tilapia.

  9. Effects of feeding fish oil on the properties of lipoproteins isolated from rhesus monkeys consuming an atherogenic diet.

    PubMed

    Soltys, P A; Mazzone, T; Wissler, R W; Vahed, S; Rangnekar, V; Lukens, J; Vesselinovitch, D; Getz, G S

    1989-04-01

    This study examined plasma lipids and lipoproteins of rhesus monkeys fed fish oil incorporated into a highly atherogenic diet containing saturated fat and cholesterol. The animals were fed diets containing 2% cholesterol and either 25% coconut oil (group I), 25% fish oil/coconut oil (1:1; group II), or 25% fish oil/coconut oil (3:1; group III) for 12 months (n = 8/group). Adding menhaden fish oil to the diet increased plasma eicosapentaenoic acid and docosahexaenoic acid and decreased plasma linoleic acid in animals fed the fish oil containing diets. Plasma concentrations of all lipoprotein fractions were decreased in the fish oil groups. VLDL isolated from group I animals exhibited beta-mobility on agarose gels but the VLDL from groups II and III animals did not. The group I VLDL was more highly enriched in cholesteryl ester than was VLDL from groups II and III. Group I LDL had a small but significant increase in cholesteryl ester content compared to group III LDL. No differences in HDL composition were observed in the 3 groups. At least 6 times less apo E was recovered in VLDL, IDL, and LDL from group III animals than from group I animals. Assuming 1 molecule of apo B per lipoprotein particle, there were 50% fewer VLDL, IDL, and LDL particles in group III than in group I animals. Group III also had significantly lower molar ratios of apo E/apo B in VLDL, IDL, and LDL than did group I animals. When VLDL from all 3 groups were incubated with J774 macrophages at equal protein concentrations, only the VLDL from the group I animals stimulated cholesterol esterification. Thus, introducing fish oil into an atherogenic diet reduced the number of VLDL, IDL and LDL particles in plasma by as much as 50%, reduced the cholesteryl ester content of the circulating lipoprotein, and reduced the ability of the VLDL to stimulate cholesterol esterification in macrophages.

  10. Experimental study of flow due to an isolated suction hole and a partially plugged suction slot

    NASA Technical Reports Server (NTRS)

    Goglia, G. L.; Wilkinson, S. P.

    1980-01-01

    Details for construction of a model of a partially plugged, laminar flow control, suction slot and an isolated hole are presented. The experimental wind tunnel facility and instrumentation is described. Preliminary boundary layer velocity profiles (without suction model) are presented and shown to be in good agreement with the Blasius laminar profile. Recommendations for the completion of the study are made. An experimental program for study of transition on a rotating disk is described along with preliminary disturbance amplification rate data.

  11. 21 CFR 870.5050 - Patient care suction apparatus.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Patient care suction apparatus. 870.5050 Section 870.5050 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... suction apparatus. (a) Identification. A patient care suction apparatus is a device used with...

  12. 21 CFR 870.5050 - Patient care suction apparatus.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Patient care suction apparatus. 870.5050 Section 870.5050 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... suction apparatus. (a) Identification. A patient care suction apparatus is a device used with...

  13. 21 CFR 874.5350 - Suction antichoke device.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Therapeutic Devices § 874.5350 Suction antichoke device. (a) Identification. A suction antichoke device is a device intended to be used in an emergency situation to remove... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Suction antichoke device. 874.5350 Section...

  14. 21 CFR 874.5350 - Suction antichoke device.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Therapeutic Devices § 874.5350 Suction antichoke device. (a) Identification. A suction antichoke device is a device intended to be used in an emergency situation to remove... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Suction antichoke device. 874.5350 Section...

  15. The ontogeny of feeding kinematics in a giant salamander Cryptobranchus alleganiensis: Does current function or phylogenetic relatedness predict the scaling patterns of movement?

    PubMed

    Deban, Stephen M; O'Reilly, James C

    2005-01-01

    Studies of the scaling of feeding movements in vertebrates have included three species that display both near-geometric growth and isometry of kinematic variables. These scaling characteristics allow one to examine the "pure" relationship of growth and movement. Despite similar growth patterns, the feeding movements of toads (Bufo) slow down more with increasing body size than those of bass (Micropterus), and sharks (Ginglymostoma). This variation might be due to major differences in the mechanism of prey capture; the bass and sharks use suction to capture prey in water, while the toad uses tongue prehension to capture prey on land. To investigate whether or not these different scaling patterns are correlated with differences in feeding mechanics, we examined the ontogenetic scaling of prey capture movements in the hellbender salamander (Cryptobranchus alleganiensis), which also has near-geometric growth. The hellbender suction feeds in the same general manner as the teleosts and shark, but is much more closely related to the toad. The feeding movements of the hellbender scale more similarly to the feeding movements of toads than to those of fishes or sharks, indicating that phylogenetic relatedness rather than biomechanical similarity predicts ontogenetic scaling patterns of movement. PMID:16351963

  16. Maximizing collection and minimizing risk: does vacuum suction sampling increase the likelihood for misinterpretation of food web connections?

    PubMed

    Chapman, Eric G; Romero, Susan A; Harwood, James D

    2010-11-01

    Molecular tools that characterize the structure of complex food webs and identify trophic connectedness in the field have become widely adopted in recent years. However, characterizing the intensity of predator-prey interactions can be prone to error. Maximizing collection success of small, fast-moving predators with vacuum suction samplers has the potential to increase the likelihood of prey DNA detection either through surface-level contamination with damaged prey or direct consumption within the sampling device. In this study, we used PCR to test the hypothesis that vacuum suction sampling will not cause an erroneous increase in the detection of 'predation', thereby incorrectly assigning trophic linkages when evaluating food web structure. We utilized general (1) Aphidoidea and (2) Collembola primers to measure the predation rates of Glenognatha foxi (Araneae: Tetragnathidae) on these prey collected by hand versus those sampled with a vacuum suction device. With both primer pairs, there was no significant increase in predators screening positive for prey DNA when sampled by vacuum suction versus those predators collected, in parallel, by hand. These results clearly validate the application of vacuum suction sampling during molecular gut-content analysis of predator-prey feeding linkages in the field. Furthermore, we found no evidence that predation was occurring inside the suction sampler because specimens collected were never observed to be feeding nor did they screen positive at greater frequencies than hand-collected individuals. Therefore, it can be concluded that the use of vacuum suction sampling devices (in this case a Modified CDC Backpack Aspirator Model 1412) is suitable for molecular gut-content analysis.

  17. To fear or to feed: the effects of turbidity on perception of risk by a marine fish.

    PubMed

    Leahy, Susannah M; McCormick, Mark I; Mitchell, Matthew D; Ferrari, Maud C O

    2011-12-23

    Coral reefs are currently experiencing a number of worsening anthropogenic stressors, with nearshore reefs suffering from increasing sedimentation because of growing human populations and development in coastal regions. In habitats where vision and olfaction serve as the primary sources of information, reduced visual input from suspended sediment may lead to significant alterations in prey fish behaviour. Here, we test whether prey compensate for reduced visual information by increasing their antipredator responses to chemically mediated risk cues in turbid conditions. Experiments with the spiny damselfish, Acanthochromis polyacanthus, found that baseline activity levels were reduced by 23 per cent in high turbidity conditions relative to low turbidity conditions. Furthermore, risk cues elicited strong antipredator responses at all turbidity levels; the strongest antipredator responses were observed in high turbidity conditions, with fish reducing their foraging by almost 40 per cent, as compared with 17 per cent for fish in clear conditions. This provides unambiguous evidence of sensory compensation in a predation context for a tropical marine fish, and suggests that prey fish may be able to behaviourally offset some of the fitness reductions resulting from anthropogenic sedimentation of their habitats.

  18. Effect of feeding lipids recovered from fish processing waste by lactic acid fermentation and enzymatic hydrolysis on antioxidant and membrane bound enzymes in rats.

    PubMed

    Rai, Amit Kumar; Bhaskar, N; Baskaran, V

    2015-06-01

    Fish oil recovered from fresh water fish visceral waste (FVW-FO) through lactic acid fermentation (FO-LAF) and enzymatic hydrolysis (FO-EH) were fed to rats to study their influence on lipid peroxidation and activities of antioxidant and membrane bound enzyme in liver, heart and brain. Feeding of FO-LAF and FO-EH resulted in increase (P < 0.05) in lipid peroxides level in serum, liver, brain and heart tissues compared to ground nut oil (control). Activity of catalase (40-235 %) and superoxide dismutase (17-143 %) also increased (P < 0.05) with incremental level of EPA + DHA in diet. The increase was similar to cod liver oil fed rats at same concentration of EPA + DHA. FO-LAF and FO-EH increased (P < 0.05) the Na(+)K(+) ATPase activity in liver and brain microsomes, Ca(+)Mg(+) ATPase in heart microsome and acetylcholine esterase in brain microsomes when fed with 5 % EPA + DHA. There was also significant change in fatty acid composition and cholesterol/phospholipid ratio in microsomes of rat fed with FVW-FO. Feeding FVW-FO recovered by biotechnological approaches enhanced the activity of antioxidant enzymes in tissues, modulates the activities of membrane bound enzymes and improved the fatty acid composition in microsomes of tissues similar to CLO. Utilization of these processing wastes for the production of valuable biofunctional products can reduce the mounting economic values of fish oil and minimize the environmental pollution problems.

  19. Infection levels of plerocercoids of the tapeworm Triaenophorus crassus and feeding strategy in two fish species from the ultra-oligotrophic Lake Achensee, Austria.

    PubMed

    Schähle, Z; Medgyesy, N; Psenner, R

    2016-01-01

    Thus far, high burdens of Triaenophorus crassus plerocercoids have been reported only in old age groups of coregonid and salmonid fishes. Here we show heavy infection with T. crassus in young whitefish Coregonus lavaretus in the ultra-oligotrophic and regulated Achensee in Tyrol, Austria. Prevalence of T. crassus on C. lavaretus was 100% in all age groups and abundance significantly increased with fish age. The mean annual accumulation of T. crassus was 5.2 parasites in 0- to 7-year-old C. lavaretus, and 2-year-old specimens already harboured a mean of 19.4 plerocercoids. In Arctic charr Salvelinus umbla, however, the prevalence of T. crassus was less than 16% and the majority of infected fish contained only one or two plerocercoids. Triaenophorus nodulosus was present neither in C. lavaretus nor in S. umbla. We assume that the heavy T. crassus infection in C. lavaretus is largely related to their zooplankton-dominated diet and to the characteristics of Achensee, while habitat choice and feeding strategy of the S. umbla population are seen to be the main reasons for their low burdens of T. crassus.

  20. Influence of salinity regime on the food-web structure and feeding ecology of fish species from Mediterranean coastal lagoons

    NASA Astrophysics Data System (ADS)

    Prado, Patricia; Vergara, Carolina; Caiola, Nuno; Ibáñez, Carles

    2014-02-01

    Dual δ15N and δ13C analyses and estimates of biomass were used to characterize the food webs of valuable fish species in three coastal lagoons of the Ebro Delta subjected to contrasting salinity regimes (polyhaline in the Tancada lagoon, mesohaline in the Encanyissada and oligohaline in the Clot lagoon). The δ13C signatures of the entire food-web including primary producers, sediment organic matter and consumers showed the most enriched values in the Tancada lagoon (from approx. -4.8‰ in sediments to -19.7‰ in fish) and the most depleted ones in the Clot lagoon (from approx. -11.4‰ in sediments to -25.4‰ in fish), consistent with dominant contributions from marine and continental sources, respectively. For δ15N, particularly high values were detected in the submersed vegetation (11.3 ± 0.3‰) together with more enriched sediment values at lower salinities (by approx. 2.5‰), suggesting that historical loadings of agricultural fertilizers are still retained by the systems and transmitted across trophic levels. Negative relationships between δ15N and salinity were also observed for the amphipod Gammarus aequicauda and the isopod Sphaeroma hookeri, suggesting some consumption of accumulated and resuspended detrital material. In contrast, δ15N signatures of fish showed lower values and inconsistent patterns, possibly because most species have a seasonal use of the lagoons. The biomass of fish species did not show a clear effect of the salinity regime (except for the mosquitofish Gambusia holbrookii), but results for mixing models suggest a diet shift from higher contribution of zooplankton size fractions in the Encanyissada (from 57 to 73%) to macrofauna at the other lagoons (from 40 to 67%). We suggest that alterations in salinity might modify the trophic dynamics of the systems from benthic to planktonic pathways, without large-scale differences in δ15N of fish suggestive of similar trophic levels.

  1. The feeding habits of Austrolethops wardi, a gobiid fish inhabiting burrows of the thalassinidean shrimp Neaxius acanthus

    NASA Astrophysics Data System (ADS)

    Hung Liu, Ha Trieu; Kneer, Dominik; Asmus, Harald; Ahnelt, Harald

    2008-09-01

    The feeding habit of Austrolethops wardi (Gobiidae) in the seagrass beds of Barrang Lompo and Bone Batang Island in the Spermonde Archipelago, South West Sulawesi, Indonesia, was investigated through gut content analysis. The feeding preferences of this species are very similar on both islands: A. wardi, a burrow associate of Neaxius acanthus, was found to feed almost exclusively on seagrass (which was found in 100% of the investigated stomachs and made up >94% of food items). However, seagrass epiphytes (<5% of food items) and animal food (<1% of food items) occurred in the guts as well, the latter predominantly in terms of copepods and to a lesser degree in other small invertebrates. These results indicate that animal food is of little importance for A. wardi. Some specimens even contained no parts of animal food.

  2. Durophagy in sharks: feeding mechanics of the hammerhead Sphyrna tiburo.

    PubMed

    Wilga, C D; Motta, P J

    2000-09-01

    This study investigates the motor pattern and head movements during feeding of a durophagus shark, the bonnethead Sphyrna tiburo, using electromyography and simultaneous high-speed video. Sphyrna tiburo feeds almost exclusively on hard-shelled crabs, with shrimp and fish taken occasionally. It captures crabs by ram feeding, then processes or reduces the prey by crushing it between molariform teeth, finally transporting the prey by suction for swallowing. The prey-crushing mechanism is distinct from that of ram or bite capture and suction transport. This crushing mechanism is accomplished by altering the duration of jaw adductor muscle activity and modifying jaw kinematics by the addition of a second jaw-closing phase. In crushing events, motor activity of the jaw adductor muscles continues (biting of the prey occurs as the jaws close and continues after the jaws have closed) throughout a second jaw-closing phase, unlike capture and transport events during which motor activity (biting) ceases at jaw closure. Sphyrna tiburo is able to take advantage of a resource (hard prey) that is not readily available to most sharks by utilizing a suite of durophagous characteristics: molariform teeth, a modified jaw protrusor muscle, altered jaw adductor activity and modified jaw kinematics. Sphyrna tiburo is a specialist feeder on crab prey as demonstrated by the lack of differences in kinematic or motor patterns when offered prey of differing hardness and its apparent lack of ability to modulate its behavior when feeding on other prey. Functional patterns are altered and coupled with modifications in dental and jaw morphology to produce diverse crushing behaviors in elasmobranchs.

  3. Control of respiration in fish, amphibians and reptiles.

    PubMed

    Taylor, E W; Leite, C A C; McKenzie, D J; Wang, T

    2010-05-01

    Fish and amphibians utilise a suction/force pump to ventilate gills or lungs, with the respiratory muscles innervated by cranial nerves, while reptiles have a thoracic, aspiratory pump innervated by spinal nerves. However, fish can recruit a hypobranchial pump for active jaw occlusion during hypoxia, using feeding muscles innervated by anterior spinal nerves. This same pump is used to ventilate the air-breathing organ in air-breathing fishes. Some reptiles retain a buccal force pump for use during hypoxia or exercise. All vertebrates have respiratory rhythm generators (RRG) located in the brainstem. In cyclostomes and possibly jawed fishes, this may comprise elements of the trigeminal nucleus, though in the latter group RRG neurons have been located in the reticular formation. In air-breathing fishes and amphibians, there may be separate RRG for gill and lung ventilation. There is some evidence for multiple RRG in reptiles. Both amphibians and reptiles show episodic breathing patterns that may be centrally generated, though they do respond to changes in oxygen supply. Fish and larval amphibians have chemoreceptors sensitive to oxygen partial pressure located on the gills. Hypoxia induces increased ventilation and a reflex bradycardia and may trigger aquatic surface respiration or air-breathing, though these latter activities also respond to behavioural cues. Adult amphibians and reptiles have peripheral chemoreceptors located on the carotid arteries and central chemoreceptors sensitive to blood carbon dioxide levels. Lung perfusion may be regulated by cardiac shunting and lung ventilation stimulates lung stretch receptors.

  4. Assessing impacts of land-applied manure from concentrated animal feeding operations on fish populations and communities

    EPA Science Inventory

    Concentrated animal feeding operation (CAFO) waste is a cost effective fertilizer. In the Midwest, networks of subsurface tile-drains expedite transport of animal hormones and nutrients from land-applied CAFO waste to adjacent waterways. The objective of this study was to evaluat...

  5. Integrated assessment of runoff from concentrated animal feeding operations: Analytical approaches, in vitro bioassays, and in vivo fish exposures

    EPA Science Inventory

    While the trend toward using concentrated animal feeding operations (CAFOs) has resulted in increased efficiency in food production, this has prompted concern regarding the impact these operations have on the environment. For example, animal waste from CAFOs can contain natural a...

  6. Feeding soy or fish meal to Alaskan reindeer (Rangifer tarandus tarandus) - effects on animal performance and meat quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fourteen reindeer were used to compare the effects of two different reindeer diets containing soybean meal (SBM) or fishmeal (WFM) as protein source) on animal growth performance, feed efficiency and ultimate meat quality. No significant difference was observed in overall weight gain between the WFM...

  7. Effects of dietary fat energy restriction and fish oil feeding on hepatic metabolic abnormalities and insulin resistance in KK mice with high-fat diet-induced obesity.

    PubMed

    Arai, Takeshi; Kim, Hyoun-ju; Hirako, Satoshi; Nakasatomi, Maki; Chiba, Hiroshige; Matsumoto, Akiyo

    2013-01-01

    We investigated the effects of dietary fat energy restriction and fish oil intake on glucose and lipid metabolism in female KK mice with high-fat (HF) diet-induced obesity. Mice were fed a lard/safflower oil (LSO50) diet consisting of 50 energy% (en%) lard/safflower oil as the fat source for 12 weeks. Then, the mice were fed various fat energy restriction (25 en% fat) diets - LSO, FO2.5, FO12.5 or FO25 - containing 0, 2.5, 12.5, or 25 en% fish oil, respectively, for 9 weeks. Conversion from a HF diet to each fat energy restriction diet significantly decreased final body weights and visceral and subcutaneous fat mass in all fat energy restriction groups, regardless of fish oil contents. Hepatic triglyceride and cholesterol levels markedly decreased in the FO12.5 and FO25 groups, but not in the LSO group. Although plasma insulin levels did not differ among groups, the blood glucose areas under the curve in the oral glucose tolerance test were significantly lower in the FO12.5 and FO25 groups. Real-time polymerase chain reaction analysis showed fatty acid synthase mRNA levels significantly decreased in the FO25 group, and stearoyl-CoA desaturase 1 mRNA levels markedly decreased in the FO12.5 and FO25 groups. These results demonstrate that body weight gains were suppressed by dietary fat energy restriction even in KK mice with HF diet-induced obesity. We also suggested that the combination of fat energy restriction and fish oil feeding decreased fat droplets and ameliorated hepatic hypertrophy and insulin resistance with suppression of de novo lipogenesis in these mice.

  8. Bite force and feeding kinematics in the eastern North Pacific Kyphosidae.

    PubMed

    Moran, Clinton Joseph; Ferry, Lara

    2014-04-01

    Some fishes that feed on attached food items possess an intramandibular joint (IMJ), which is thought to increase maximum gape and facilitate contact between the tooth-bearing surface and the substrate. However, the mechanical consequences of using an IMJ to remove attached food items from the substrate are still poorly understood. We examined the most prominent eastern North Pacific kyphosid, the scraper: Girella nigricans and two other kyphosids, Medialuna californiensis and Hermosilla azurea, which occupy similar habitats. Of the three species, G. nigricans had the highest theoretical bite force per unit length. We examined the feeding mechanics of G. nigricans in two different feeding scenarios: a scraping behavior elicited on a block of brine shrimp gelatin and a picking behavior elicited on Ulva sp. We measured cranial elevation, lower jaw rotation, premaxillary protrusion, premaxillary rotation, gape maximum, and intramandibular rotation. Ulva treatments produced significantly greater cranial rotation, when compared to gelatin treatments. Gelatin treatments were associated with greater lower jaw rotation and larger gape. Premaxillary rotation and premaxillary protrusion did not differ between treatments. Intramandibular rotation occurred only when G. nigricans physically contacted the gelatin, suggesting the IMJ is a passive joint with no associated musculature. We also noted that G. nigricans do not appear to use suction to draw food into the mouth. The lack of suction and the presence of the IMJ suggest that the jaws of G. nigricans are specialized for maximizing jaw force when scraping. PMID:24497484

  9. Bernoulli Suction Effect on Soap Bubble Blowing?

    NASA Astrophysics Data System (ADS)

    Davidson, John; Ryu, Sangjin

    2015-11-01

    As a model system for thin-film bubble with two gas-liquid interfaces, we experimentally investigated the pinch-off of soap bubble blowing. Using the lab-built bubble blower and high-speed videography, we have found that the scaling law exponent of soap bubble pinch-off is 2/3, which is similar to that of soap film bridge. Because air flowed through the decreasing neck of soap film tube, we studied possible Bernoulli suction effect on soap bubble pinch-off by evaluating the Reynolds number of airflow. Image processing was utilized to calculate approximate volume of growing soap film tube and the volume flow rate of the airflow, and the Reynolds number was estimated to be 800-3200. This result suggests that soap bubbling may involve the Bernoulli suction effect.

  10. [Contusion-suction trauma after globe injuries].

    PubMed

    Kroll, P; Stoll, W; Kirchhoff, E

    1983-06-01

    An analysis of ball injuries treated during the last 3 years at Münster University Eye Hospital revealed a difference in the kind of traumata caused by air-filled balls and by solid, inelastic balls. The pathomechanism of a "contusion-suction trauma" is discussed; this would offer a satisfactory explanation not only for injuries of the anterior segment, but also for retinal changes at the outer periphery and the posterior pole.

  11. Ultra-fast underwater suction traps.

    PubMed

    Vincent, Olivier; Weisskopf, Carmen; Poppinga, Simon; Masselter, Tom; Speck, Thomas; Joyeux, Marc; Quilliet, Catherine; Marmottant, Philippe

    2011-10-01

    Carnivorous aquatic Utricularia species catch small prey animals using millimetre-sized underwater suction traps, which have fascinated scientists since Darwin's early work on carnivorous plants. Suction takes place after mechanical triggering and is owing to a release of stored elastic energy in the trap body accompanied by a very fast opening and closing of a trapdoor, which otherwise closes the trap entrance watertight. The exceptional trapping speed--far above human visual perception--impeded profound investigations until now. Using high-speed video imaging and special microscopy techniques, we obtained fully time-resolved recordings of the door movement. We found that this unique trapping mechanism conducts suction in less than a millisecond and therefore ranks among the fastest plant movements known. Fluid acceleration reaches very high values, leaving little chance for prey animals to escape. We discovered that the door deformation is morphologically predetermined, and actually performs a buckling/unbuckling process, including a complete trapdoor curvature inversion. This process, which we predict using dynamical simulations and simple theoretical models, is highly reproducible: the traps are autonomously repetitive as they fire spontaneously after 5-20 h and reset actively to their ready-to-catch condition.

  12. Whale sharks, Rhincodon typus, aggregate around offshore platforms in Qatari waters of the Arabian Gulf to feed on fish spawn.

    PubMed

    Robinson, David P; Jaidah, Mohammed Y; Jabado, Rima W; Lee-Brooks, Katie; Nour El-Din, Nehad M; Al Malki, Ameena A; Elmeer, Khaled; McCormick, Paul A; Henderson, Aaron C; Pierce, Simon J; Ormond, Rupert F G

    2013-01-01

    Whale sharks, Rhincodon typus, are known to aggregate to feed in a small number of locations in tropical and subtropical waters. Here we document a newly discovered major aggregation site for whale sharks within the Al Shaheen oil field, 90 km off the coast of Qatar in the Arabian Gulf. Whale sharks were observed between April and September, with peak numbers observed between May and August. Density estimates of up to 100 sharks within an area of 1 km(2) were recorded. Sharks ranged between four and eight metres' estimated total length (mean 6.92 ± 1.53 m). Most animals observed were actively feeding on surface zooplankton, consisting primarily of mackerel tuna, Euthynnus affinis, eggs.

  13. Whale Sharks, Rhincodon typus, Aggregate around Offshore Platforms in Qatari Waters of the Arabian Gulf to Feed on Fish Spawn

    PubMed Central

    Robinson, David P.; Jaidah, Mohammed Y.; Jabado, Rima W.; Lee-Brooks, Katie; Nour El-Din, Nehad M.; Malki, Ameena A. Al.; Elmeer, Khaled; McCormick, Paul A.; Henderson, Aaron C.; Pierce, Simon J.; Ormond, Rupert F. G.

    2013-01-01

    Whale sharks, Rhincodon typus, are known to aggregate to feed in a small number of locations in tropical and subtropical waters. Here we document a newly discovered major aggregation site for whale sharks within the Al Shaheen oil field, 90 km off the coast of Qatar in the Arabian Gulf. Whale sharks were observed between April and September, with peak numbers observed between May and August. Density estimates of up to 100 sharks within an area of 1 km2 were recorded. Sharks ranged between four and eight metres’ estimated total length (mean 6.92±1.53 m). Most animals observed were actively feeding on surface zooplankton, consisting primarily of mackerel tuna, Euthynnus affinis, eggs. PMID:23516456

  14. Application of Novel CO2 Laser-Suction Device.

    PubMed

    Straus, David; Moftakhar, Roham; Fink, Yoel; Patel, Deval; Byrne, Richard W

    2013-12-01

    Background Development of the flexible CO2 fiber has presented new opportunities for the use of precision laser cutting in cranial procedures. The efficacy of the CO2 scalpel is further enhanced by combining it with a fluid removal suction capability. Objectives We report our experience with a novel CO2 laser-suction device. Methods The novel laser-suction device was designed in conjunction with OmniGuide Inc. (Cambridge, Massachusetts, USA). We performed a case review of its use in firm tumors that were resistant to resection by bipolar, suction, and ultrasonic aspirator. Results The laser-suction device was applied in three tumors where resection with ultrasonic aspiration failed. Tumor resection using the laser-suction device was successful in all three cases. There were no complications related to the laser-suction device. There were no instances of intraoperative device malfunction. Discussion The CO2 laser combined with suction is a useful instrument for resection of firm tumors that prove to be resistant to ultrasonic aspiration. We also find it to be useful in settings where precise tissue incisions are desired with minimal manipulation. In our experience, the surgical efficiency of the CO2 laser is improved by the laser-suction device. This device allows the surgeon to utilize a suction device and laser in a single hand and enables concurrent use of bipolar electrocautery without repeated instrument changes.

  15. Optimal concentrations in nectar feeding

    PubMed Central

    Kim, Wonjung; Gilet, Tristan; Bush, John W. M.

    2011-01-01

    Nectar drinkers must feed quickly and efficiently due to the threat of predation. While the sweetest nectar offers the greatest energetic rewards, the sharp increase of viscosity with sugar concentration makes it the most difficult to transport. We here demonstrate that the sugar concentration that optimizes energy transport depends exclusively on the drinking technique employed. We identify three nectar drinking techniques: active suction, capillary suction, and viscous dipping. For each, we deduce the dependence of the volume intake rate on the nectar viscosity and thus infer an optimal sugar concentration consistent with laboratory measurements. Our results provide the first rationale for why suction feeders typically pollinate flowers with lower sugar concentration nectar than their counterparts that use viscous dipping. PMID:21949358

  16. Evaluation of hypopharyngeal suction to eliminate aspiration: the Retro-Esophageal Suction (REScue) catheter.

    PubMed

    Belafsky, Peter C; Mehdizadeh, O B; Ledgerwood, L; Kuhn, M

    2015-02-01

    Profound oropharyngeal dysphagia (OPD) is common and costly. Treatment options are limited. The purpose of this investigation was to evaluate the utility of hypopharyngeal suction at the upper esophageal sphincter (UES) to eliminate aspiration. Five different catheters were passed retrograde up the esophagus and positioned at the UES in a cadaver model of profound OPD. Suction was affixed to each catheter. 10 cc of barium was administered into the pyriform sinus, and videofluoroscopy was utilized to evaluate the presence of aspiration. 6 trials were administered per catheter and for a no catheter control. The outcome measures were the incidence of aspiration, the NIH Swallow Safety Scale (NIH-SSS), and UES opening. Control trials with no suction resulted in an aspiration rate of 100 % (6/6 trials). Negative pressure through 16, 18, 24, and 30 Fr catheter resulted in an aspiration rate of 0 % (0/24 trials; p < 0.001), and suction through a 12-Fr catheter resulted in an aspiration rate of 33 % (2/6 trials; p > 0.05). The mean NIH-SSS improved from 7.0 (±0.0) in the control to 0 (±0.0) with hypopharyngeal suction (18 Fr nasogastric catheter; p < 0.001). Mean UES opening improved from 0.0 (±0.0) mm in the control condition to 8.6 (±0.2) mm with a hypopharyngeal catheter (16 Fr Foley catheter; p < 0.001). Negative pressure applied through retro-esophageal suction catheters (>12 Fr) at the level of the UES reduced aspiration by 100 % and significantly increased UES opening in a cadaveric model of profound oropharyngeal dysphagia.

  17. Cloning and characterization of leptin in a Perciform fish, the striped bass (Morone saxatilis): control of feeding and regulation by nutritional state.

    PubMed

    Won, Eugene T; Baltzegar, David A; Picha, Matthew E; Borski, Russell J

    2012-08-01

    In mammals, leptin is an anorexigenic peptide hormone that regulates energy homeostasis. It is produced predominantly by white adipose tissue and circulates as an endocrine indicator of energy reserves. Teleost leptin has been characterized in a few fish species, but its regulation is not well understood, particularly in response to nutritional status. In this study, we cloned a putative leptin in striped bass (Morone saxatilis) and report the first characterization of leptin in a Perciforme, the largest and most diverse order of fish. The striped bass leptin coding sequence was 65% homologous with pufferfish, 52% with Atlantic salmon, and 46% with human. PCR showed that leptin mRNA was exclusively expressed in the liver, and not adipose or other tissues. The leptin coding sequence of striped bass and the more widely cultured hybrid striped bass variety (HSB; Morone chrysops, white bass×M. saxatilis) were identical. We then evaluated whether the metabolic status of HSB might alter leptin gene expression. Juvenile HSB were subjected to 3weeks feed deprivation followed by 3weeks of refeeding. Quantitative PCR showed that fasting for 3weeks reduced hepatic leptin mRNA levels relative to fed controls. Leptin mRNA levels then increased upon refeeding, albeit levels were not completely restored to those seen in control fish fed throughout the experiment. Intraperitoneal injection of human leptin suppressed appetite in HSB. In as much as hepatic HSB leptin mRNA is regulated by nutritional state and has a corresponding anorexigenic effect, our results suggest that leptin may play a role in energy homeostasis in these advanced Perciformes. PMID:22569172

  18. Cloning and characterization of leptin in a Perciform fish, the striped bass (Morone saxatilis): control of feeding and regulation by nutritional state.

    PubMed

    Won, Eugene T; Baltzegar, David A; Picha, Matthew E; Borski, Russell J

    2012-08-01

    In mammals, leptin is an anorexigenic peptide hormone that regulates energy homeostasis. It is produced predominantly by white adipose tissue and circulates as an endocrine indicator of energy reserves. Teleost leptin has been characterized in a few fish species, but its regulation is not well understood, particularly in response to nutritional status. In this study, we cloned a putative leptin in striped bass (Morone saxatilis) and report the first characterization of leptin in a Perciforme, the largest and most diverse order of fish. The striped bass leptin coding sequence was 65% homologous with pufferfish, 52% with Atlantic salmon, and 46% with human. PCR showed that leptin mRNA was exclusively expressed in the liver, and not adipose or other tissues. The leptin coding sequence of striped bass and the more widely cultured hybrid striped bass variety (HSB; Morone chrysops, white bass×M. saxatilis) were identical. We then evaluated whether the metabolic status of HSB might alter leptin gene expression. Juvenile HSB were subjected to 3weeks feed deprivation followed by 3weeks of refeeding. Quantitative PCR showed that fasting for 3weeks reduced hepatic leptin mRNA levels relative to fed controls. Leptin mRNA levels then increased upon refeeding, albeit levels were not completely restored to those seen in control fish fed throughout the experiment. Intraperitoneal injection of human leptin suppressed appetite in HSB. In as much as hepatic HSB leptin mRNA is regulated by nutritional state and has a corresponding anorexigenic effect, our results suggest that leptin may play a role in energy homeostasis in these advanced Perciformes.

  19. Environmental concentrations of the selective serotonin reuptake inhibitor fluoxetine impact specific behaviors involved in reproduction, feeding and predator avoidance in the fish Pimephales promelas (fathead minnow)

    PubMed Central

    Weinberger, Joel; Klaper, Rebecca

    2014-01-01

    Pharmaceuticals and personal care products (PPCP) have been found in surface waters worldwide, but little is understood of their effects on the wildlife that inhabit these waters. Fluoxetine (Prozac; Eli Lilly), a highly prescribed selective serotonin reuptake inhibitor (SSRI), is a commonly found PPCP in surface water. The purpose of this project was to determine if environmentally relevant concentrations of fluoxetine impact behavior that is important for population survival in native fish species, including reproduction, feeding and predator avoidance. Chronic 4-week exposures were conducted with doses ranging from 100 ng/L to 100 μg/L to cover a range of environmentally relevant concentrations up to higher concentrations comparable to other published studies with the same drug that have documented various physiological impacts. Pimephales promelas (fathead minnow), a species native to North America, was used as it conducts a range of specific mating behaviors and therefore serves as an excellent model of specific impacts on brain function. Fluoxetine concentrations as low as 1 μg/L, a concentration that has been found in many freshwater environments, were found to significantly impact mating behavior, specifically nest building and defending in male fish. Males were also found to display aggression, isolation, and repetitive behaviors at higher concentrations. Female mating behavior was largely unaffected. In addition, predator avoidance behaviors in males and females were also impacted at 1 μg/L. Feeding was impacted at 10 μg/L and in the highest exposure (100 μg/L), egg production was limited by deaths of females due to significant male aggressive behaviors in first two weeks of exposure. Specific behavioral changes occurred at each concentration (most noticeably 1 μg/L and 100 μg/L) indicating a dose dependent effect that triggered different responses at lower exposures versus higher exposures or differential impacts of dose depending on brain region

  20. Apparent digestibility of Asian carp and common carp-derived fish meals in feeds for hybrid striped bass Morone saxatilis female x M. chrysops male and rainbow trout Oncorhynchus mykiss

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Apparent digestibility coefficients (ADCs) of nutrients (crude protein, amino acids, crude lipid, fatty acids, and minerals) were determined for fish meals derived from menhaden, Asian carp (combination of silver and bighead carps), and common carp in feeds for hybrid striped bass and rainbow trout....

  1. Salmon testes meal as a functional feed additive in fish meal and plant-protein based diets for rainbow trout(Oncorhynchus mykiss walbaum)and nile tilapia(Oreochromis niloticus L.) fry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We report that salmon testes meal (TM) produced from Alaskan seafood processing byproducts is a potential protein source for aquafeed formulations. A series of feeding trials was conducted using three different fish species; including Nile tilapia, rainbow trout, and white sturgeon at their early gr...

  2. Probiotics, immunostimulants, plant products and oral vaccines, and their role as feed supplements in the control of bacterial fish diseases.

    PubMed

    Newaj-Fyzul, A; Austin, B

    2015-11-01

    There is a rapidly increasing literature pointing to the success of probiotics, immunostimulants, plant products and oral vaccines in immunomodulation, namely stimulation of the innate, cellular and/or humoral immune response, and the control of bacterial fish diseases. Probiotics are regarded as live micro-organisms administered orally and leading to health benefits. However, in contrast with the use in terrestrial animals, a diverse range of micro-organisms have been evaluated in aquaculture with the mode of action often reflecting immunomodulation. Moreover, the need for living cells has been questioned. Also, key subcellular components, including lipopolysaccharides, have been attributed to the beneficial effect in fish. Here, there is a link with immunostimulants, which may also be administered orally. Furthermore, numerous plant products have been reported to have health benefits, namely protection against disease for which stimulation of some immune parameters has been reported. Oral vaccines confer protection against some diseases, although the mode of action is usually linked to humoral rather than the innate and cellular immune responses. This review explores the relationship between probiotics, immunostimulants, plant products and oral vaccines.

  3. Feeding kinematics and performance of Hawaiian stream gobies, Awaous guamensis and Lentipes concolor: linkage of functional morphology and ecology.

    PubMed

    Maie, Takashi; Wilson, Megan P; Schoenfuss, Heiko L; Blob, Richard W

    2009-03-01

    Distributions of Hawaiian stream fishes are typically interrupted by waterfalls that divide streams into multiple segments. Larvae hatch upstream, are flushed into the ocean, and must climb these waterfalls to reach adult habitats when returning back to freshwater as part of an amphidromous life cycle. Stream surveys and studies of climbing performance show that Lentipes concolor Gill can reach fast-flowing upper stream segments but that Awaous guamensis Valenciennes reaches only slower, lower stream segments. Gut content analyses for these two species indicate considerable overlap in diet, suggesting that feeding kinematics and performance of these two species might be comparable. Alternatively, feeding kinematics and performance of these species might be expected to differ in relation to the different flow regimes in their habitat (feeding in faster stream currents for L. concolor versus in slower currents for A. guamensis). To test these alternative hypotheses, we compared food capturing kinematics and performance during suction feeding behaviors of A. guamensis and L. concolor using morphological data and high-speed video. Lentipes concolor showed both a significantly larger gape angle and faster jaw opening than A. guamensis. Geometric models calculated that despite the inverse relationship of gape size and suction pressure generation, the fast jaw motions of L. concolor allow it to achieve higher pressure differentials than A. guamensis. Such elevated suction pressure would enhance the ability of L. concolor to successfully capture food in the fast stream reaches it typically inhabits. Differences in jaw morphology may contribute to these differences in performance, as the lever ratio for jaw opening is about 10% lower in L. concolor compared with A. guamensis, suiting the jaws of L. concolor better for fast opening. PMID:19107821

  4. Feeding kinematics and performance of Hawaiian stream gobies, Awaous guamensis and Lentipes concolor: linkage of functional morphology and ecology.

    PubMed

    Maie, Takashi; Wilson, Megan P; Schoenfuss, Heiko L; Blob, Richard W

    2009-03-01

    Distributions of Hawaiian stream fishes are typically interrupted by waterfalls that divide streams into multiple segments. Larvae hatch upstream, are flushed into the ocean, and must climb these waterfalls to reach adult habitats when returning back to freshwater as part of an amphidromous life cycle. Stream surveys and studies of climbing performance show that Lentipes concolor Gill can reach fast-flowing upper stream segments but that Awaous guamensis Valenciennes reaches only slower, lower stream segments. Gut content analyses for these two species indicate considerable overlap in diet, suggesting that feeding kinematics and performance of these two species might be comparable. Alternatively, feeding kinematics and performance of these species might be expected to differ in relation to the different flow regimes in their habitat (feeding in faster stream currents for L. concolor versus in slower currents for A. guamensis). To test these alternative hypotheses, we compared food capturing kinematics and performance during suction feeding behaviors of A. guamensis and L. concolor using morphological data and high-speed video. Lentipes concolor showed both a significantly larger gape angle and faster jaw opening than A. guamensis. Geometric models calculated that despite the inverse relationship of gape size and suction pressure generation, the fast jaw motions of L. concolor allow it to achieve higher pressure differentials than A. guamensis. Such elevated suction pressure would enhance the ability of L. concolor to successfully capture food in the fast stream reaches it typically inhabits. Differences in jaw morphology may contribute to these differences in performance, as the lever ratio for jaw opening is about 10% lower in L. concolor compared with A. guamensis, suiting the jaws of L. concolor better for fast opening.

  5. Sustainable production of toxin free marine microalgae biomass as fish feed in large scale open system in the Qatari desert.

    PubMed

    Das, Probir; Thaher, Mahmoud Ibrahim; Hakim, Mohammed Abdul Quadir Mohd Abdul; Al-Jabri, Hareb Mohammed S J

    2015-09-01

    Mass cultivation of microalgae biomass for feed should be cost effective and toxin free. Evaporation loss in Qatar can be as high as 2 cm/d. Hence, production of marine microalgae biomass in Qatar would also require mitigating water loss as there was only very limited groundwater reserve. To address these issues, a combination of four growth conditions were applied to a 25,000 L raceway pond: locally isolated microalgae strain was selected which could grow in elevated salinity; strain that did not require silica and vitamins; volume of the culture would increase over time keeping denser inoculum in the beginning, and evaporation water loss would be balanced by adding seawater only. A local saline tolerant Nannochloropsis sp. was selected which did not require silica and vitamins. When the above conditions were combined in the pond, average areal biomass productivities reached 20.37 g/m(2)/d, and the culture was not contaminated by any toxic microalgae.

  6. Sustainable production of toxin free marine microalgae biomass as fish feed in large scale open system in the Qatari desert.

    PubMed

    Das, Probir; Thaher, Mahmoud Ibrahim; Hakim, Mohammed Abdul Quadir Mohd Abdul; Al-Jabri, Hareb Mohammed S J

    2015-09-01

    Mass cultivation of microalgae biomass for feed should be cost effective and toxin free. Evaporation loss in Qatar can be as high as 2 cm/d. Hence, production of marine microalgae biomass in Qatar would also require mitigating water loss as there was only very limited groundwater reserve. To address these issues, a combination of four growth conditions were applied to a 25,000 L raceway pond: locally isolated microalgae strain was selected which could grow in elevated salinity; strain that did not require silica and vitamins; volume of the culture would increase over time keeping denser inoculum in the beginning, and evaporation water loss would be balanced by adding seawater only. A local saline tolerant Nannochloropsis sp. was selected which did not require silica and vitamins. When the above conditions were combined in the pond, average areal biomass productivities reached 20.37 g/m(2)/d, and the culture was not contaminated by any toxic microalgae. PMID:26022971

  7. Stick tight: suction adhesion on irregular surfaces in the northern clingfish

    PubMed Central

    Wainwright, Dylan K.; Kleinteich, Thomas; Kleinteich, Anja; Gorb, Stanislav N.; Summers, Adam P.

    2013-01-01

    The northern clingfish, Gobiesox maeandricus, is able to adhere to slippery, fouled and irregular surfaces in the marine intertidal environment. We have found that the fish can adhere equally well to surfaces with a broad range of surface roughness, from the finest sandpaper (Ra = 15 µm) to textures suitable for removing finish from flooring (Ra = 269 µm). The fishes outperform man-made suction cups, which only adhere to the smoothest surfaces. The adhesive forces of clingfish correspond to pressures 0.2–0.5 atm below ambient and are 80–230 times the body weight of the fish. The tenacity appears related to hierarchically structured microvilli around the edges of the adhesive disc that are similar in size and aspect ratio to the setae found on the feet of geckoes, spiders and insects. This points to a possible biomimetic solution to the problem of reversibly adhering to irregular, submerged surfaces. PMID:23637393

  8. The influence of fish cage culture on δ13C and δ15N of filter-feeding Bivalvia (Mollusca).

    PubMed

    Benedito, E; Figueroa, L; Takeda, A M; Manetta, G I

    2013-11-01

    The objective of this study was to evaluate the effect of Oreochromis niloticus cage culture promoted variations in the δ13C and δ15N in Corbicula fluminea (Mollusca; Bivalvia) and in the sediment of an aquatic food web. Samples were taken before and after net cage installation in the Rosana Reservoir (Paranapanema River, PR-SP). Samples of specimens of the bivalve filterer C. fluminea and samples of sediment were collected using a modified Petersen grab. All samples were dried in an oven (60 °C) for 72 hours, macerated to obtain homogenous fine powders and sent for carbon (δ13C) and nitrogen (δ15N) isotopic value analysis in a mass spectrometer. There were significant differences in the δ13C and δ15N values of the invertebrate C. fluminea between the beginning and the end of the experiment. There were no differences between the δ13C and δ15N values of sediment. These results indicate that the installation of fish cage culture promoted impacts in the isotopic composition of the aquatic food web organisms, which could exert influence over the native species and the ecosystem.

  9. Influence of feeding a fish oil-containing diet to young, lean, adult dogs: effects on lipid metabolites, postprandial glycaemia and body weight.

    PubMed

    de Godoy, Maria R C; Conway, Charlotte E; Mcleod, Kyle R; Harmon, David L

    2015-01-01

    The aim of this study was to determine the effect of feeding a fish oil (FO)-containing diet on lipid and protein metabolism, postprandial glycaemia and body weight in young, lean, adult dogs. Eight female Beagles were randomly assigned to one of two isonitrogenous and isoenergetic diets, Control or FO, in a crossover design. At the beginning of the experiment and at 30 and 60 d, a baseline blood sample was collected and the dogs then were fed their daily ration. Nitrogen balance began at 07:00 h on day 63 of each experimental period and ended at 07:00 h on day 69. On day 66 of each period, a single dose (7.5 mg/kg) of (15)N-glycine was administered orally to each dog via gelatin capsule. Postprandial glycaemia did not differ between treatments or among sampling days within treatment. Cholesterol concentration was increased (p<0.05) on the Control treatment throughout the experiment when compared to values of day 0. Dogs fed the FO treatment had higher plasma triglyceride and ghrelin concentrations than those fed the Control treatment. Body weight and food intake did not differ between dietary treatments. Faecal excretion was increased (p<0.05) in the FO treatment. Dry matter digestibility was decreased (p<0.05) and fat digestibility tended (p<0.10) to decrease in the FO treatment. Overall, feeding a FO-containing diet showed a protective effect against the rise of plasma cholesterol and it increased plasma ghrelin concentration. However, FO supplementation did not appear to affect protein metabolism or postprandial glycaemia in adult lean dogs. PMID:26490201

  10. Influence of feeding a fish oil-containing diet to young, lean, adult dogs: effects on lipid metabolites, postprandial glycaemia and body weight.

    PubMed

    de Godoy, Maria R C; Conway, Charlotte E; Mcleod, Kyle R; Harmon, David L

    2015-01-01

    The aim of this study was to determine the effect of feeding a fish oil (FO)-containing diet on lipid and protein metabolism, postprandial glycaemia and body weight in young, lean, adult dogs. Eight female Beagles were randomly assigned to one of two isonitrogenous and isoenergetic diets, Control or FO, in a crossover design. At the beginning of the experiment and at 30 and 60 d, a baseline blood sample was collected and the dogs then were fed their daily ration. Nitrogen balance began at 07:00 h on day 63 of each experimental period and ended at 07:00 h on day 69. On day 66 of each period, a single dose (7.5 mg/kg) of (15)N-glycine was administered orally to each dog via gelatin capsule. Postprandial glycaemia did not differ between treatments or among sampling days within treatment. Cholesterol concentration was increased (p<0.05) on the Control treatment throughout the experiment when compared to values of day 0. Dogs fed the FO treatment had higher plasma triglyceride and ghrelin concentrations than those fed the Control treatment. Body weight and food intake did not differ between dietary treatments. Faecal excretion was increased (p<0.05) in the FO treatment. Dry matter digestibility was decreased (p<0.05) and fat digestibility tended (p<0.10) to decrease in the FO treatment. Overall, feeding a FO-containing diet showed a protective effect against the rise of plasma cholesterol and it increased plasma ghrelin concentration. However, FO supplementation did not appear to affect protein metabolism or postprandial glycaemia in adult lean dogs.

  11. Contribution to the feeding ecology of the banded puffer fish Colomesus psittacus (Tetraodontidae) in north Brazilian mangrove creeks.

    PubMed

    Krumme, U; Keuthen, H; Saint-Paul, U; Villwock, W

    2007-08-01

    Stomach contents were examined from 102 banded puffer, Colomesus psittacus (Tetraodontidae), caught from intertidal mangrove creeks at diurnal neap tides between June and September, 1997 (early dry season) near Bragança (north Brazil). The study found that C. psittacus were specialized predators of Cirripedia (Balanus spp.) and Brachyuran crabs (Uca spp., Pachygrapsus gracilis) (mean: 58 and 38% by dry weight, respectively), emphasizing a short food chain in the mangrove system. Cirripedia and Brachyura dominated the diet in all size classes, however, the prey spectrum narrowed with fish size. The mean daily consumption of Cirripedia and Brachyura was 6.2% body weight of C. psittacus. On average C. psittacus consumed 100.3 g x ha(-1) x d(-1) of Cirripedia and 178.7 g x ha(-1) x d(-1) of Brachyura (wet weight). The predation on Brachyuran crabs--a significant driver of fluxes of organic matter and energy in the system--provides C. psittacus with an important ecological function in the mangrove food web. A plant-animal interaction is proposed where C. psittacus exerts a mutually beneficial cleaning function on the Aufwuchs (Cirripedia and associated epibiota) of Rhizophora mangle stilt roots. Our results and those of other studies suggest that C. psittacus encounter optimum foraging conditions in the mangrove at high inundations at daylight (spring tide-day) whereas darkness and low inundations are linked to poor foraging conditions (neap tide-night). The C. psittacus resource could be used as an alternative income in the region in terms of i) sustainable catch and filet processing for exports to East Asia, ii) developing certified aquaculture methods for breeding puffers for the aquarium trade.

  12. Contribution to the feeding ecology of the banded puffer fish Colomesus psittacus (Tetraodontidae) in north Brazilian mangrove creeks.

    PubMed

    Krumme, U; Keuthen, H; Saint-Paul, U; Villwock, W

    2007-08-01

    Stomach contents were examined from 102 banded puffer, Colomesus psittacus (Tetraodontidae), caught from intertidal mangrove creeks at diurnal neap tides between June and September, 1997 (early dry season) near Bragança (north Brazil). The study found that C. psittacus were specialized predators of Cirripedia (Balanus spp.) and Brachyuran crabs (Uca spp., Pachygrapsus gracilis) (mean: 58 and 38% by dry weight, respectively), emphasizing a short food chain in the mangrove system. Cirripedia and Brachyura dominated the diet in all size classes, however, the prey spectrum narrowed with fish size. The mean daily consumption of Cirripedia and Brachyura was 6.2% body weight of C. psittacus. On average C. psittacus consumed 100.3 g x ha(-1) x d(-1) of Cirripedia and 178.7 g x ha(-1) x d(-1) of Brachyura (wet weight). The predation on Brachyuran crabs--a significant driver of fluxes of organic matter and energy in the system--provides C. psittacus with an important ecological function in the mangrove food web. A plant-animal interaction is proposed where C. psittacus exerts a mutually beneficial cleaning function on the Aufwuchs (Cirripedia and associated epibiota) of Rhizophora mangle stilt roots. Our results and those of other studies suggest that C. psittacus encounter optimum foraging conditions in the mangrove at high inundations at daylight (spring tide-day) whereas darkness and low inundations are linked to poor foraging conditions (neap tide-night). The C. psittacus resource could be used as an alternative income in the region in terms of i) sustainable catch and filet processing for exports to East Asia, ii) developing certified aquaculture methods for breeding puffers for the aquarium trade. PMID:18094820

  13. 21 CFR 880.5740 - Suction snakebite kit.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Suction snakebite kit. 880.5740 Section 880.5740 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL HOSPITAL AND PERSONAL USE DEVICES General Hospital and Personal Use Therapeutic Devices § 880.5740 Suction snakebite kit....

  14. Transient bacteremia following endotracheal suctioning in ventilated newborns.

    PubMed

    Storm, W

    1980-03-01

    Endotracheal suctioning is a routine procedure in ventilated newborns. A study of ten neonates demonstrates the association of transient bacteremia with endotracheal suctioning. This complication in ventilated newborns, with colonization of the respiratory tract by the same organism, must be considered in the pathogenesis of systemic infection.

  15. 21 CFR 870.4430 - Cardiopulmonary bypass intracardiac suction control.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass intracardiac suction control. 870.4430 Section 870.4430 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND....4430 Cardiopulmonary bypass intracardiac suction control. (a) Identification. A cardiopulmonary...

  16. 21 CFR 874.5350 - Suction antichoke device.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Suction antichoke device. 874.5350 Section 874.5350 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Therapeutic Devices § 874.5350 Suction antichoke device....

  17. 21 CFR 874.5350 - Suction antichoke device.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Suction antichoke device. 874.5350 Section 874.5350 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Therapeutic Devices § 874.5350 Suction antichoke device....

  18. 21 CFR 874.5350 - Suction antichoke device.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Suction antichoke device. 874.5350 Section 874.5350 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Therapeutic Devices § 874.5350 Suction antichoke device....

  19. 21 CFR 880.5740 - Suction snakebite kit.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Suction snakebite kit. 880.5740 Section 880.5740 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL HOSPITAL AND PERSONAL USE DEVICES General Hospital and Personal Use Therapeutic Devices § 880.5740 Suction snakebite kit....

  20. Aquatic prey capture in ray-finned fishes: a century of progress and new directions.

    PubMed

    Ferry-Graham, L A; Lauder, G V

    2001-05-01

    The head of ray-finned fishes is structurally complex and is composed of numerous bony, muscular, and ligamentous elements capable of intricate movement. Nearly two centuries of research have been devoted to understanding the function of this cranial musculoskeletal system during prey capture in the dense and viscous aquatic medium. Most fishes generate some amount of inertial suction to capture prey in water. In this overview we trace the history of functional morphological analyses of suction feeding in ray-finned fishes, with a particular focus on the mechanisms by which suction is generated, and present new data using a novel flow imaging technique that enables quantification of the water flow field into the mouth. We begin with a brief overview of studies of cranial anatomy and then summarize progress on understanding function as new information was brought to light by the application of various forms of technology, including high-speed cinematography and video, pressure, impedance, and bone strain measurement. We also provide data from a new technique, digital particle image velocimetry (DPIV) that allows us to quantify patterns of flow into the mouth. We believe that there are three general areas in which future progress needs to occur. First, quantitative three-dimensional studies of buccal and opercular cavity dimensions during prey capture are needed; sonomicrometry and endoscopy are techniques likely to yield these data. Second, a thorough quantitative analysis of the flow field into the mouth during prey capture is necessary to understand the effect of head movement on water in the vicinity of the prey; three-dimensional DPIV analyses will help to provide these data. Third, a more precise understanding of the fitness effects of structural and functional variables in the head coupled with rigorous statistical analyses will allow us to better understand the evolutionary consequences of intra- and interspecific variation in cranial morphology and function

  1. Transition Flight Experiments on a Swept Wing With Suction

    NASA Technical Reports Server (NTRS)

    Maddalon, D. V.; Collier, F. S., Jr.; Montoya, L. C.; Land, C. K.

    1989-01-01

    Flight experiments were conducted on a 30 degree swept wing with a perforated leading edge by systematically varying the location and amount of suction over a range of Mach number and Reynolds number. Suction was varied chordwise ahead of the front spar from either the front or rear direction by sealing spanwise perforated strips. Transition from laminar to turbulent flow was due to leading edge turbulence contamination or crossflow disturbance growth and/or Tollmien-Schlichting disturbance growth-depending on the test configuration, flight condition, and suction location. A state-of-the-art linear stability theory which accounts for body and streamline curvature and compressibility was used to study the boundary layer stability as suction location and magnitude varied. N-factor correlations with transition location were made for various suction configurations.

  2. Suction socket suspension for below-knee amputees.

    PubMed

    Roberts, R A

    1986-03-01

    In this study the current use of suction suspension for below-knee prostheses is examined by means of two questionnaire surveys. The experience of 56 below-knee (B-K) amputees wearing suction socket prostheses is evaluated comparing suction prostheses with previously worn limbs. A high degree of satisfaction was found, with amputees on the whole reporting improved skin condition, diminished pain, and increased activity levels compared to previous prosthetic history. The experience and opinions of 466 certified prosthetist members of the American Orthotist Prosthetist Association are examined in the second survey, including degree of contact, success, and evaluation of problems in using suction suspension for the B-K amputee. This survey indicated limited contact and familiarity with B-K suction suspension, with only 22% stating they had made this type of prosthesis. Prosthetists cited characteristics of the B-K residual limb as the chief deterrent to a successful fitting.

  3. Preliminary insights into the incorporation of rosemary extract (Rosmarinus officinalis L.) in fish feed: influence on performance and physiology of gilthead seabream (Sparus aurata).

    PubMed

    Hernández, A; García García, B; Caballero, M J; Hernández, M D

    2015-08-01

    Gilthead seabream (Sparus aurata) were fed a basal (control) diet and four experimental diets (R600, R1200, R1800 and R2400), containing 600, 1200, 1800 and 2400 mg kg(-1), respectively, of rosemary extract (Rosmarinus officinalis L.). At 4 and 12 weeks from the beginning of the ongrowing period, the fish were sacrificed, blood was drawn to obtain plasma and the liver and intestines were dissected. Growth and feed intake were unaffected by rosemary extract addition. A histological examination of the intestine revealed no differences among the dosages, while the liver showed a sharp decrease in hepatic steatosis in diets supplemented with rosemary extract. Furthermore, plasma alanine aminotransferase was lower with these diets at the end of the ongrowing period. Rosemary extract reduced the plasma levels of glucose and triglycerides on week 4 and glucose and HDL/LDL cholesterol ratio on week 12, suggesting better transport and energy metabolism of the lipids. Overall, the most evident effect of rosemary extract was observed with the 600 mg kg(-1) dose. PMID:25968936

  4. Preliminary insights into the incorporation of rosemary extract (Rosmarinus officinalis L.) in fish feed: influence on performance and physiology of gilthead seabream (Sparus aurata).

    PubMed

    Hernández, A; García García, B; Caballero, M J; Hernández, M D

    2015-08-01

    Gilthead seabream (Sparus aurata) were fed a basal (control) diet and four experimental diets (R600, R1200, R1800 and R2400), containing 600, 1200, 1800 and 2400 mg kg(-1), respectively, of rosemary extract (Rosmarinus officinalis L.). At 4 and 12 weeks from the beginning of the ongrowing period, the fish were sacrificed, blood was drawn to obtain plasma and the liver and intestines were dissected. Growth and feed intake were unaffected by rosemary extract addition. A histological examination of the intestine revealed no differences among the dosages, while the liver showed a sharp decrease in hepatic steatosis in diets supplemented with rosemary extract. Furthermore, plasma alanine aminotransferase was lower with these diets at the end of the ongrowing period. Rosemary extract reduced the plasma levels of glucose and triglycerides on week 4 and glucose and HDL/LDL cholesterol ratio on week 12, suggesting better transport and energy metabolism of the lipids. Overall, the most evident effect of rosemary extract was observed with the 600 mg kg(-1) dose.

  5. Effect of replacing fish meal with extruded soybean meal on growth, feed utilization and apparent nutrient digestibility of juvenile white shrimp ( Litopenaeus vannamei)

    NASA Astrophysics Data System (ADS)

    Yang, Qihui; Tan, Beiping; Dong, Xiaohui; Chi, Shuyan; Liu, Hongyu

    2015-10-01

    Extruded soybean meal (ESBM) was evaluated as a protein source for partial replacement of fish meal (FM) in diets of juvenile Litopenaeus vannamei. In the control diet (Diet 1), FM protein was replaced with increasing dietary levels of ESBM (4.28%, 8.40%, 12.62%, 16.82%, and 25.26%) at 10%, 20%, 30%, 40%, and 60% levels (Diets 2 to 6, respectively). An eight-week feeding trial was conducted on 720 juvenile shrimp (0.67 g ± 0.01 g mean initial weight), and nutrient digestibility of the six diets was determined. ESBM could replace 20% of FM without causing a significant reduction in growth of shrimp, but other dietary treatments strongly affected whole body composition. Crude protein content of the whole body fed Diet 6 was significantly lower than that fed Diet 2 ( P < 0.05), while crude lipid content of the whole body fed Diet 5 or 6 was significantly higher than that fed Diet 2 ( P < 0.05). Protein digestibilities of Diets 5 and 6 were significantly lower than that of Diet 1 ( P < 0.05). Digestibility of lipids ranged from 96.97% in Diet 6 to 98.34% in Diet 3, whereas dry matter digestibility decreased with increasing replacement level. This study indicates that 20% FM replacement with ESBM in the basic diet containing 40% protein and 30% FM is optimal for juvenile L. vannamei.

  6. Effects of feed access after hatch and inclusion of fish oil and medium chain fatty acids in a pre-starter diet on broiler chicken growth performance and humoral immunity.

    PubMed

    Lamot, D M; van der Klein, S A S; van de Linde, I B; Wijtten, P J A; Kemp, B; van den Brand, H; Lammers, A

    2016-09-01

    Delayed feed and water access is known to impair growth performance of day old broiler chickens. Although effects of feed access on growth performance and immune function of broilers have been examined before, effects of dietary composition and its potential interaction with feed access are hardly investigated. This experiment aimed to determine whether moment of first feed and water access after hatch and pre-starter composition (0 to 7 days) affect growth rate and humoral immune function in broiler chickens. Direct fed chickens received feed and water directly after placement in the grow-out facility, whilst delayed fed chickens only after 48 h. Direct and delayed fed chickens received a control pre-starter diet, or a diet containing medium chain fatty acids (MCFA) or fish oil. At 21 days, chickens were immunized by injection of sheep red blood cells. The mortality rate depended on an interaction between feed access and pre-starter composition (P=0.014). Chickens with direct feed access fed the control pre-starter diet had a higher risk for mortality than chickens with delayed feed access fed the control pre-starter diet (16.4% v. 4.2%) whereas the other treatment groups were in-between. BW gain and feed intake till 25 days in direct fed chickens were higher compared with delayed fed chickens, whilst gain to feed ratio was lower. Within the direct fed chickens, the control pre-starter diet resulted in the highest BW at 28 days and the MCFA pre-starter diet the lowest (Δ=2.4%), whereas this was opposite for delayed fed chickens (Δ=3.0%; P=0.033). Provision of MCFA resulted in a 4.6% higher BW gain and a higher gain to feed ratio compared with other pre-starter diets, but only during the period it was provided (2 to 7 days). Minor treatment effects were found for humoral immune response by measuring immunoglobulins, agglutination titers, interferon gamma (IFN- γ ), and complement activity. Concluding, current inclusion levels of fish oil (5 g/kg) and MCFA (30 g

  7. Dynamical effects of suction/heating on turbulent boundary layers

    NASA Astrophysics Data System (ADS)

    Blackwelder, Ron

    1992-01-01

    The main emphasis of this quarter has been to test the effects of suction in a controlled environment with the emulated wall eddy structure. A study of the curved working wall of the test section in the Goertler Wind Tunnel showed that there were sufficient stresses within the plexiglas that cutting elongated slits for suction would probably cause the surface to develop step-type roughnesses. Thus several individual holes were initially drilled along the streamline direction in a spanwise region between two vortices. Air was withdrawn through this series of holes to provide a semi-continuous region of suction. Differing rates of suction through these holes were used to explore the effects upon the eddy structure. These preliminary results were obtained using visualization; i.e., smoke as introduced via a smoke wire into the boundary layer. Images were captured using a video camera and analyzed to determine the best suction rates. The preliminary results showed that suction has a large effect upon individual streaks of low speed fluid. Without the suction, the low speed region lying in the upwelling zone between two streamwise vortices was broken down by a secondary instability. This instability typically caused the low speed fluid marked with the smoke to oscillate from side to side in a manifestation of an inflectional instability in the spanwise direction as found and reported earlier in this research. With increasing distance downstream, the oscillation amplitude grew very rapidly until it broke down into complete turbulence.

  8. How to perform open tracheal suction via an endotracheal tube.

    PubMed

    Credland, Nicola

    2016-04-27

    Rationale and key points Tracheal suction involves the removal of pulmonary secretions from the respiratory tract using negative pressure under sterile conditions. Practitioners should be aware of the indications for, and risks associated with, open tracheal suction via an endotracheal tube. ▶ Respiratory assessment of the patient should be carried out to identify when tracheal suction is required. ▶ A suction pressure of 80-120mmHg is recommended, and suction should last no longer than 15 seconds. ▶ Reassurance and support should be given to the patient to minimise any discomfort and distress that might result from tracheal suction. Reflective activity Clinical skills articles can help update your practice and ensure it remains evidence-based. Apply this article to your practice. Reflect on and write a short account of: 1. How you think this article will change your practice when performing open tracheal suction via an endotracheal tube. 2. How you could use this resource to educate your colleagues. Subscribers can upload their reflective accounts at: rcni.com/portfolio .

  9. Comparative feeding kinematics and performance of odontocetes: belugas, Pacific white-sided dolphins and long-finned pilot whales.

    PubMed

    Kane, E A; Marshall, C D

    2009-12-01

    Cetaceans are thought to display a diversity of feeding modes that are often described as convergent with other more basal aquatic vertebrates (i.e. actinopterygians). However, the biomechanics of feeding in cetaceans has been relatively ignored by functional biologists. This study investigated the feeding behavior, kinematics and pressure generation of three odontocetes with varying feeding modes (belugas, Delphinapterus leucas; Pacific white-sided dolphins, Lagenorhynchus obliquidens; and long-finned pilot whales, Globicephala melas). Four feeding phases were recognized in all odontocetes: (I) preparatory, (II) jaw opening, (III) gular depression, and (IV) jaw closing. Belugas relied on a feeding mode that was composed of discrete ram and suction components. Pacific white-sided dolphins fed using ram, with some suction for compensation or manipulation of prey. Pilot whales were kinematically similar to belugas but relied on a combination of ram and suction that was less discrete than belugas. Belugas were able to purse the anterior lips to occlude lateral gape and form a small, circular anterior aperture that is convergent with feeding behaviors observed in more basal vertebrates. Suction generation in odontocetes is a function of hyolingual displacement and rapid jaw opening, and is likely to be significantly enhanced by lip pursing behaviors. Some degree of subambient pressure was measured in all species, with belugas reaching 126 kPa. Functional variations of suction generation during feeding demonstrate a wider diversity of feeding behaviors in odontocetes than previously thought. However, odontocete suction generation is convergent with that of more basal aquatic vertebrates. PMID:19946072

  10. Development of Cutting and Suction Device with Twist Blade Screw for Minimally Invasive Surgery: Evaluation of Suction Performance

    PubMed Central

    Fujii, Yusuke; Suzuki, Takashi; Tamura, Manabu; Muragaki, Yoshihiro; Iseki, Hiroshi

    2015-01-01

    In this study, we aim to develop a narrow-diameter and long-bore device for minimally invasive surgery that achieves the simultaneous cutting and suction of body tissue such as the diseased part of an organ. In this paper, we propose a screw made of a thin metal plate, and we developed a prototype device using this screw. For smooth operation, the suction performance must be superior to the cutting performance. Therefore, we performed experiments and evaluated the suction performance of the developed device assuming the crushed tissue pieces correspond to a highly viscous fluid. From the results, we confirmed that the suction volume is almost proportional to the rotation speed of the screw in the low speed range, and the device has an upper limit of suction volume at a certain rotation speed. Considering practical use, its proportional speed range is suitable for the device controllability of cutting and suction volume, and the size of the device tip needs to be 1 mm or more. Based on these conditions, we are planning to examine the shape of the cutting edge for realizing efficient cutting and suction and we will complete the device. PMID:26132592

  11. Development of Cutting and Suction Device with Twist Blade Screw for Minimally Invasive Surgery: Evaluation of Suction Performance.

    PubMed

    Fujii, Yusuke; Suzuki, Takashi; Tamura, Manabu; Muragaki, Yoshihiro; Iseki, Hiroshi

    2015-01-01

    In this study, we aim to develop a narrow-diameter and long-bore device for minimally invasive surgery that achieves the simultaneous cutting and suction of body tissue such as the diseased part of an organ. In this paper, we propose a screw made of a thin metal plate, and we developed a prototype device using this screw. For smooth operation, the suction performance must be superior to the cutting performance. Therefore, we performed experiments and evaluated the suction performance of the developed device assuming the crushed tissue pieces correspond to a highly viscous fluid. From the results, we confirmed that the suction volume is almost proportional to the rotation speed of the screw in the low speed range, and the device has an upper limit of suction volume at a certain rotation speed. Considering practical use, its proportional speed range is suitable for the device controllability of cutting and suction volume, and the size of the device tip needs to be 1 mm or more. Based on these conditions, we are planning to examine the shape of the cutting edge for realizing efficient cutting and suction and we will complete the device. PMID:26132592

  12. Optically transparent multi-suction electrode arrays

    PubMed Central

    Nagarah, John M.; Stowasser, Annette; Parker, Rell L.; Asari, Hiroki; Wagenaar, Daniel A.

    2015-01-01

    Multielectrode arrays (MEAs) allow for acquisition of multisite electrophysiological activity with submillisecond temporal resolution from neural preparations. The signal to noise ratio from such arrays has recently been improved by substrate perforations that allow negative pressure to be applied to the tissue; however, such arrays are not optically transparent, limiting their potential to be combined with optical-based technologies. We present here multi-suction electrode arrays (MSEAs) in quartz that yield a substantial increase in the detected number of units and in signal to noise ratio from mouse cortico-hippocampal slices and mouse retina explants. This enables the visualization of stronger cross correlations between the firing rates of the various sources. Additionally, the MSEA's transparency allows us to record voltage sensitive dye activity from a leech ganglion with single neuron resolution using widefield microscopy simultaneously with the electrode array recordings. The combination of enhanced electrical signals and compatibility with optical-based technologies should make the MSEA a valuable tool for investigating neuronal circuits. PMID:26539078

  13. 21 CFR 878.4780 - Powered suction pump.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4780 Powered suction pump. (a... support system. The device may be used during surgery in the operating room or at the patient's...

  14. 21 CFR 878.4780 - Powered suction pump.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4780 Powered suction pump. (a... support system. The device may be used during surgery in the operating room or at the patient's...

  15. 21 CFR 878.4780 - Powered suction pump.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4780 Powered suction pump. (a... support system. The device may be used during surgery in the operating room or at the patient's...

  16. 21 CFR 878.4780 - Powered suction pump.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4780 Powered suction pump. (a... support system. The device may be used during surgery in the operating room or at the patient's...

  17. 21 CFR 878.4780 - Powered suction pump.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4780 Powered suction pump. (a... support system. The device may be used during surgery in the operating room or at the patient's...

  18. A trial of suction drainage in inguinal hernia repair.

    PubMed

    Beacon, J; Hoile, R W; Ellis, H

    1980-08-01

    A prospective randomized trial was conducted on 301 adult males undergoing inguinal herniorrhaphy to assess the value of postoperative suction drainage. Hernias were classified into 'complicated' and 'simple'. In the 'complicated' group suction drainage for 24 h significantly reduced the incidence of wound haematoma, seroma or infection from 48.7 per cent to 17.6 per cent (P < 0.01); there was also a noticeable effect on the postoperative morbidity in the 'simple' hernias, although this just failed to achieve significance (4.5 per cent in the suction group compared with 9.8 per cent in the controls). It is concluded that suction drainage should be employed postoperatively following repair of hernias where dissection may be difficult or where other complicating factors are present.

  19. Complete feeds-intensive systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Most commercially cultivated fish are raised in high-density culture systems where the assumption is that the contribution of natural foods to the nutrition of the fish is insignificant. Thus, intensively cultured fish must be fed a nutritionally complete feed. A short section on the concept and im...

  20. Colonization of Yankauer suction catheters with pathogenic organisms.

    PubMed

    Brown, Melissa; Willms, David

    2005-10-01

    Oral suction devices may be fomites for nosocomial infections. This study was designed to evaluate the rate of contamination of Yankauer suction catheters. Among the 20 catheters tested, 16 (80%) yielded cultures for pathogens. Seven (35%) were colonized with multiple pathogens. Among the organisms encountered included methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococci (VRE). These devices should be handled and stored with appropriate care.

  1. The generation of side force by distributed suction

    NASA Technical Reports Server (NTRS)

    Roberts, Leonard; Hong, John

    1993-01-01

    This report provides an approximate analysis of the generation of side force on a cylinder placed horizontal to the flow direction by the application of distributed suction on the rearward side of the cylinder. Relationships are derived between the side force coefficients and the required suction coefficients necessary to maintain attached flow on one side of the cylinder, thereby inducing circulation around the cylinder and a corresponding side force.

  2. Displacement of oropharyngeal structures during suction-swallowing cycles.

    PubMed

    Engelke, W; Glombek, J; Psychogios, M; Schneider, S; Ellenberger, D; Santander, P

    2014-07-01

    Suction ability plays an important role in supporting oral nutrition and needs special care following neurological disorders and tumor-associated defects. However, the details of suction are still poorly understood. The present study evaluates displacement of orofacial structures during suction and deglutition based on manometric controlled MRI. Nine healthy subjects were scanned wearing an intraoral mouthpiece for water intake by suction and subsequent swallowing. Suction-swallowing cycles were identified by intraoral negative pressure. Midsagittal MRI slices (3 T; temporal resolution 0.53 s) were analyzed at rest, suction and pharyngeal swallowing. The mandibular displacement was measured as the distance between the anterior nasal spine and the inferior point of the mandible. Following areas were defined: subpalatal compartment (SCA), retrolingual (RLA), epipharyngeal (EPA) and mouth floor area (MFA). During rest, an average distance of 7 cm was observed between the mandibular measurement points. The measured SCA was 3.67 cm(2), the RLA 6.98 cm(2), the EPA 9.00 cm(2) and the MFA 15.21 cm(2) (average values). At the end of suction, the mandibular distance reduces (to 6.88 cm), the SCA increases significantly (to 5.96 cm(2); p = 0.0002), the RLA decreases (to 6.45 cm(2)), the EPA increases (to 10.59 cm(2)) and the MFA decreases (to 15.02 cm(2)). During deglutition, the mandible lifted significantly (to 6.81 cm; p = 0.0276), the SCA reduced to zero, the RLA was not measurable, the EPA reduces significantly (to 3.01 cm(2); p < 0.0001) and the MFA increases (to 16.36 cm(2)). According to these observations, a combined displacement of the tongue in an anteroposterior direction with active tongue dorsum-velum contact appears to be the predominant activity during suction and responsible for the expansion of the subpalatal area.

  3. The generation of side force by distributed suction

    NASA Astrophysics Data System (ADS)

    Roberts, Leonard; Hong, John

    1993-05-01

    This report provides an approximate analysis of the generation of side force on a cylinder placed horizontal to the flow direction by the application of distributed suction on the rearward side of the cylinder. Relationships are derived between the side force coefficients and the required suction coefficients necessary to maintain attached flow on one side of the cylinder, thereby inducing circulation around the cylinder and a corresponding side force.

  4. Differing ERP patterns caused by suction and puff stimuli.

    PubMed

    Choi, Mi-Hyun; Kim, Hyung-Sik; Baek, Ji-Hye; Lee, Jung-Chul; Park, Sung-Jun; Jeong, Ul-Ho; Gim, Seon-Young; You, Ji Hye; Kim, Sung-Pil; Lim, Dae-Woon; Kim, Hyun-Jun; Chung, Soon-Cheol

    2015-05-01

    The present study compared event-related potential (ERP) patterns for two stimuli types, puff and suction, by applying these stimuli to the fingers; ERP patterns for the two stimuli were compared at C3, an area related to somatosensory perception, and at FC5, an area related to motor function. Participants were 12 healthy males in their 20s (mean age=23.1±2.0 years). One session consisted of a Control Phase (3s), a Stimulation Phase (3s), and a Rest Phase (9s). During the Stimulation Phase, a 4-psi suction or puff stimulus was applied to the first joint of the right index finger. After completion of the session, a subjective magnitude test was presented. In all phases, electroencephalography signals were recorded. We extracted maximum positive amplitude and minimum negative amplitude as well as relevant latency values for C3 and FC5 signals. Suction and puff stimuli had similar subjective magnitude scores. For both C3 and FC5, the maximum and minimum amplitude latency was reached earlier for the suction stimulus than for the puff stimulus. In conclusion, when suction and puff stimuli of the same intensity were applied to the fingers, the suction stimulus caused a more sensitive response in the somatosensory area (C3) and motor area (FC5) than did the puff stimulus.

  5. Endotracheal suctioning in intubated newborns: an integrative literature review.

    PubMed

    Gonçalves, Roberta Lins; Tsuzuki, Lucila Midori; Carvalho, Marcos Giovanni Santos

    2015-01-01

    Evidence-based practices search for the best available scientific evidence to support problem solving and decision making. Because of the complexity and amount of information related to health care, the results of methodologically sound scientific papers must be integrated by performing literature reviews. Although endotracheal suctioning is the most frequently performed invasive procedure in intubated newborns in neonatal intensive care units, few Brazilian studies of good methodological quality have examined this practice, and a national consensus or standardization of this technique is lacking. Therefore, the purpose of this study was to review secondary studies on the subject to establish recommendations for endotracheal suctioning in intubated newborns and promote the adoption of best-practice concepts when conducting this procedure. An integrative literature review was performed, and the recommendations of this study are to only perform endotracheal suctioning in newborns when there are signs of tracheal secretions and to avoid routinely performing the procedure. In addition, endotracheal suctioning should be conducted by at least two people, the suctioning time should be less than 15 seconds, the negative suction pressure should be below 100 mmHg, and hyperoxygenation should not be used on a routine basis. If indicated, oxygenation is recommended with an inspired oxygen fraction value that is 10 to 20% greater than the value of the previous fraction, and it should be performed 30 to 60 seconds before, during and 1 minute after the procedure. Saline instillation should not be performed routinely, and the standards for invasive procedures must be respected.

  6. Suction blister fluid as potential body fluid for biomarker proteins.

    PubMed

    Kool, Jeroen; Reubsaet, Léon; Wesseldijk, Feikje; Maravilha, Raquel T; Pinkse, Martijn W; D'Santos, Clive S; van Hilten, Jacobus J; Zijlstra, Freek J; Heck, Albert J R

    2007-10-01

    Early diagnosis is important for effective disease management. Measurement of biomarkers present at the local level of the skin could be advantageous in facilitating the diagnostic process. The analysis of the proteome of suction blister fluid, representative for the interstitial fluid of the skin, is therefore a desirable first step in the search for potential biomarkers involved in biological pathways of particular diseases. Here, we describe a global analysis of the suction blister fluid proteome as potential body fluid for biomarker proteins. The suction blister fluid proteome was compared with a serum proteome analyzed using identical protocols. By using stringent criteria allowing less than 1% false positive identifications, we were able to detect, using identical experimental conditions and amount of starting material, 401 proteins in suction blister fluid and 240 proteins in serum. As a major result of our analysis we construct a prejudiced list of 34 proteins, relatively highly and uniquely detected in suction blister fluid as compared to serum, with established and putative characteristics as biomarkers. We conclude that suction blister fluid might potentially serve as a good alternative biomarker body fluid for diseases that involve the skin.

  7. Self-pumping suction/propulsion for laminar flow bodies

    NASA Astrophysics Data System (ADS)

    Rogers, K. H.; King, D. A.

    1984-06-01

    An analysis is presented to investigate the feasibility of a self-pumping suction system for a very low drag suction laminar flow control (SLFC) underwater test body. The nose and afterbody of a torpedo-like body are contoured such that a prominent low-pressure region in the aft part of the body can serve as a suction pump to suck the boundary layer fluid through the circumferential surface-slots and thus laminarize the entire body length forward of the aft low-pressure peak. The results indicate that it is feasible to laminarize a test body in this fashion at a design speed, such as 40 knots; but that the laminarization of a particular configuration is limited to a band of speeds at and near the design speed. If an SLFC test body with a wide range of speed capability is desired, then a controllable-speed suction pump and controllable suction distribution along the body are indicated. The analysis includes a suction system design calculation example and should be a useful reference for future development of undersea SLFC vehicles.

  8. Endotracheal suctioning in intubated newborns: an integrative literature review

    PubMed Central

    Gonçalves, Roberta Lins; Tsuzuki, Lucila Midori; Carvalho, Marcos Giovanni Santos

    2015-01-01

    Evidence-based practices search for the best available scientific evidence to support problem solving and decision making. Because of the complexity and amount of information related to health care, the results of methodologically sound scientific papers must be integrated by performing literature reviews. Although endotracheal suctioning is the most frequently performed invasive procedure in intubated newborns in neonatal intensive care units, few Brazilian studies of good methodological quality have examined this practice, and a national consensus or standardization of this technique is lacking. Therefore, the purpose of this study was to review secondary studies on the subject to establish recommendations for endotracheal suctioning in intubated newborns and promote the adoption of best-practice concepts when conducting this procedure. An integrative literature review was performed, and the recommendations of this study are to only perform endotracheal suctioning in newborns when there are signs of tracheal secretions and to avoid routinely performing the procedure. In addition, endotracheal suctioning should be conducted by at least two people, the suctioning time should be less than 15 seconds, the negative suction pressure should be below 100 mmHg, and hyperoxygenation should not be used on a routine basis. If indicated, oxygenation is recommended with an inspired oxygen fraction value that is 10 to 20% greater than the value of the previous fraction, and it should be performed 30 to 60 seconds before, during and 1 minute after the procedure. Saline instillation should not be performed routinely, and the standards for invasive procedures must be respected. PMID:26465249

  9. Oronasopharyngeal suction versus no suction in normal, term and vaginally born infants: a prospective randomised controlled trial.

    PubMed

    Gungor, Sadettin; Teksoz, Ertan; Ceyhan, Temel; Kurt, Ercan; Goktolga, Umit; Baser, Iskender

    2005-10-01

    This prospective randomised controlled trial aimed to compare the effects of oronasopharyngeal suction with those of no suction in normal, term and vaginally born infants and was performed at a Turkish tertiary hospital from June 2003 to January 2004. A total of 140 newborns were enrolled in the trial (n = 70 per group). The no suction group showed lower mean heart rates through the 3rd and 6th minutes and higher SaO(2) values through the first 6 mins of life (P < 0.001). The maximum time to reach SaO2 of >or= 92% (6 vs. 11 min) and >or= 86% (5 vs. 8 min) were shorter in the no suction group (P < 0.001).

  10. Suction-generated noise in an anatomic silicon ear model.

    PubMed

    Luxenberger, Wolfgang; Lahousen, T; Walch, C

    2012-10-01

    The objectives of this study were to evaluate noise levels generated during micro-suction aural toilet using an anatomic silicon ear model. It is an experimental study. In an anatomic ear model made of silicone, the eardrum was replaced by a 1-cm diameter microphone of a calibrated sound-level measuring device. Ear wax was removed using the sucker of a standard ENT treatment unit (Atmos Servant 5(®)). Mean and peak sound levels during the suction procedure were recorded with suckers of various diameters (Fergusson-Frazier 2.7-4 mm as well as Rosen 1.4-2.5 mm). Average noise levels during normal suction in a distance of 1 cm in front of the eardrum ranged between 97 and 103.5 dB(A) (broadband noise). Peak noise levels reached 118 dB(A). During partial obstruction of the sucker by cerumen or dermal flakes, peak noise levels reached 146 dB(A). Peak noise levels observed during the so-called clarinet phenomena were independent of the diameter or type of suckers used. Although micro-suction aural toilet is regarded as an established, widespread and usually safe method to clean the external auditory canal, some caution seems advisable. The performance of long-lasting suction periods straight in front of the eardrum without sound-protecting earwax between sucker and eardrum should be avoided. In particular, when clarinet phenomena are occurring (as described above), the suction procedure should be aborted immediately. In the presence of dermal flakes blocking the auditory canal, cleaning with micro-forceps or other non-suctioning instruments might represent a reasonable alternative.

  11. Replacement of Marine Fish Oil with de novo Omega-3 Oils from Transgenic Camelina sativa in Feeds for Gilthead Sea Bream (Sparus aurata L.).

    PubMed

    Betancor, Mónica B; Sprague, M; Montero, D; Usher, S; Sayanova, O; Campbell, P J; Napier, J A; Caballero, M J; Izquierdo, M; Tocher, D R

    2016-10-01

    Omega-3 (n-3) long-chain polyunsaturated fatty acids (LC-PUFA) are essential components of the diet of all vertebrates. The major dietary source of n-3 LC-PUFA for humans has been fish and seafood but, paradoxically, farmed fish are also reliant on marine fisheries for fish meal and fish oil (FO), traditionally major ingredients of aquafeeds. Currently, the only sustainable alternatives to FO are vegetable oils, which are rich in C18 PUFA, but devoid of the eicosapentaenoic (EPA) and docosahexaenoic acids (DHA) abundant in FO. Two new n-3 LC-PUFA sources obtained from genetically modified (GM) Camelina sativa containing either EPA alone (ECO) or EPA and DHA (DCO) were compared to FO and wild-type camelina oil (WCO) in juvenile sea bream. Neither ECO nor DCO had any detrimental effects on fish performance, although final weight of ECO-fed fish (117 g) was slightly lower than that of FO- and DCO-fed fish (130 and 127 g, respectively). Inclusion of the GM-derived oils enhanced the n-3 LC-PUFA content in fish tissues compared to WCO, although limited biosynthesis was observed indicating accumulation of dietary fatty acids. The expression of genes involved in several lipid metabolic processes, as well as fish health and immune response, in both liver and anterior intestine were altered in fish fed the GM-derived oils. This showed a similar pattern to that observed in WCO-fed fish reflecting the hybrid fatty acid profile of the new oils. Overall the data indicated that the GM-derived oils could be suitable alternatives to dietary FO in sea bream.

  12. Replacement of Marine Fish Oil with de novo Omega-3 Oils from Transgenic Camelina sativa in Feeds for Gilthead Sea Bream (Sparus aurata L.).

    PubMed

    Betancor, Mónica B; Sprague, M; Montero, D; Usher, S; Sayanova, O; Campbell, P J; Napier, J A; Caballero, M J; Izquierdo, M; Tocher, D R

    2016-10-01

    Omega-3 (n-3) long-chain polyunsaturated fatty acids (LC-PUFA) are essential components of the diet of all vertebrates. The major dietary source of n-3 LC-PUFA for humans has been fish and seafood but, paradoxically, farmed fish are also reliant on marine fisheries for fish meal and fish oil (FO), traditionally major ingredients of aquafeeds. Currently, the only sustainable alternatives to FO are vegetable oils, which are rich in C18 PUFA, but devoid of the eicosapentaenoic (EPA) and docosahexaenoic acids (DHA) abundant in FO. Two new n-3 LC-PUFA sources obtained from genetically modified (GM) Camelina sativa containing either EPA alone (ECO) or EPA and DHA (DCO) were compared to FO and wild-type camelina oil (WCO) in juvenile sea bream. Neither ECO nor DCO had any detrimental effects on fish performance, although final weight of ECO-fed fish (117 g) was slightly lower than that of FO- and DCO-fed fish (130 and 127 g, respectively). Inclusion of the GM-derived oils enhanced the n-3 LC-PUFA content in fish tissues compared to WCO, although limited biosynthesis was observed indicating accumulation of dietary fatty acids. The expression of genes involved in several lipid metabolic processes, as well as fish health and immune response, in both liver and anterior intestine were altered in fish fed the GM-derived oils. This showed a similar pattern to that observed in WCO-fed fish reflecting the hybrid fatty acid profile of the new oils. Overall the data indicated that the GM-derived oils could be suitable alternatives to dietary FO in sea bream. PMID:27590240

  13. Fishmeal-free Atlantic salmon feed formulation shows promise - Joint research between TCFFI, USDA and EWOS uses new diet for post-smolt to food-size fish

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The 2 MT/week of Atlantic salmon that The Conservation Fund Freshwater Institute provided to market in March and April of 2016 were fed a custom diet during nearly 90% of their growth that met the following sustainability criteria: - Fishmeal free - GMO free - Zero wild fish in: fish out according t...

  14. Dielectric elastomer actuators for octopus inspired suction cups.

    PubMed

    Follador, M; Tramacere, F; Mazzolai, B

    2014-09-25

    Suction cups are often found in nature as attachment strategy in water. Nevertheless, the application of the artificial counterpart is limited by the dimension of the actuators and their usability in wet conditions. A novel design for the development of a suction cup inspired by octopus suckers is presented. The main focus of this research was on the modelling and characterization of the actuation unit, and a first prototype of the suction cup was realized as a proof of concept. The actuation of the suction cup is based on dielectric elastomer actuators. The presented device works in a wet environment, has an integrated actuation system, and is soft. The dimensions of the artificial suction cups are comparable to proximal octopus suckers, and the attachment mechanism is similar to the biological counterpart. The design approach proposed for the actuator allows the definition of the parameters for its development and for obtaining a desired pressure in water. The fabricated actuator is able to produce up to 6 kPa of pressure in water, reaching the maximum pressure in less than 300 ms.

  15. Octopus-like suction cups: from natural to artificial solutions.

    PubMed

    Tramacere, F; Follador, M; Pugno, N M; Mazzolai, B

    2015-05-13

    Octopus suckers are able to attach to all nonporous surfaces and generate a very strong attachment force. The well-known attachment features of this animal result from the softness of the sucker tissues and the surface morphology of the portion of the sucker that is in contact with objects or substrates. Unlike artificial suction cups, octopus suckers are characterized by a series of radial grooves that increase the area subjected to pressure reduction during attachment. In this study, we constructed artificial suction cups with different surface geometries and tested their attachment performances using a pull-off setup. First, smooth suction cups were obtained for casting; then, sucker surfaces were engraved with a laser cutter. As expected, for all the tested cases, the engraving treatment enhanced the attachment performance of the elastomeric suction cups compared with that of the smooth versions. Moreover, the results indicated that the surface geometry with the best attachment performance was the geometry most similar to octopus sucker morphology. The results obtained in this work can be utilized to design artificial suction cups with higher wet attachment performance.

  16. Octopus-like suction cups: from natural to artificial solutions.

    PubMed

    Tramacere, F; Follador, M; Pugno, N M; Mazzolai, B

    2015-06-01

    Octopus suckers are able to attach to all nonporous surfaces and generate a very strong attachment force. The well-known attachment features of this animal result from the softness of the sucker tissues and the surface morphology of the portion of the sucker that is in contact with objects or substrates. Unlike artificial suction cups, octopus suckers are characterized by a series of radial grooves that increase the area subjected to pressure reduction during attachment. In this study, we constructed artificial suction cups with different surface geometries and tested their attachment performances using a pull-off setup. First, smooth suction cups were obtained for casting; then, sucker surfaces were engraved with a laser cutter. As expected, for all the tested cases, the engraving treatment enhanced the attachment performance of the elastomeric suction cups compared with that of the smooth versions. Moreover, the results indicated that the surface geometry with the best attachment performance was the geometry most similar to octopus sucker morphology. The results obtained in this work can be utilized to design artificial suction cups with higher wet attachment performance. PMID:25970079

  17. Dielectric elastomer actuators for octopus inspired suction cups.

    PubMed

    Follador, M; Tramacere, F; Mazzolai, B

    2014-01-01

    Suction cups are often found in nature as attachment strategy in water. Nevertheless, the application of the artificial counterpart is limited by the dimension of the actuators and their usability in wet conditions. A novel design for the development of a suction cup inspired by octopus suckers is presented. The main focus of this research was on the modelling and characterization of the actuation unit, and a first prototype of the suction cup was realized as a proof of concept. The actuation of the suction cup is based on dielectric elastomer actuators. The presented device works in a wet environment, has an integrated actuation system, and is soft. The dimensions of the artificial suction cups are comparable to proximal octopus suckers, and the attachment mechanism is similar to the biological counterpart. The design approach proposed for the actuator allows the definition of the parameters for its development and for obtaining a desired pressure in water. The fabricated actuator is able to produce up to 6 kPa of pressure in water, reaching the maximum pressure in less than 300 ms. PMID:25253019

  18. Rotary blood pump control strategy for preventing left ventricular suction.

    PubMed

    Wang, Yu; Koenig, Steven C; Slaughter, Mark S; Giridharan, Guruprasad A

    2015-01-01

    The risk for left ventricular (LV) suction while maintaining adequate perfusion over a range of physiologic conditions during continuous flow LV assist device (LVAD) support is a significant clinical concern. To address this challenge, we developed a suction prevention and physiologic control (SPPC) algorithm for use with axial and centrifugal LVADs. The SPPC algorithm uses two gain-scheduled, proportional-integral controllers that maintain a differential pump speed (ΔRPM) above a user-defined threshold to prevent LV suction, while maintaining an average reference differential pressure (ΔP) between the LV and aorta to provide physiologic perfusion. Efficacy and robustness of the proposed algorithm were evaluated in silico during simulated rest and exercise test conditions for (1) ΔP/ΔRPM excessive setpoint (ES); (2) rapid eightfold increase in pulmonary vascular resistance (PVR); and (3) ES and PVR. Hemodynamic waveforms (LV pressure and volume; aortic pressure and flow) were simulated and analyzed to identify suction event(s), quantify total flow output (pump + cardiac output), and characterize the performance of the SPPC algorithm. The results demonstrated that the proposed SPPC algorithm prevented LV suction while maintaining physiologic perfusion for all simulated test conditions, and warrants further investigation in vivo. PMID:25248043

  19. Turbulence, Temperature, and Turbidity: The Ecomechanics of Predator-Prey Interactions in Fishes.

    PubMed

    Higham, Timothy E; Stewart, William J; Wainwright, Peter C

    2015-07-01

    Successful feeding and escape behaviors in fishes emerge from precise integration of locomotion and feeding movements. Fishes inhabit a wide range of habitats, including still ponds, turbulent rivers, and wave-pounded shorelines, and these habitats vary in several physical variables that can strongly impact both predator and prey. Temperature, the conditions of ambient flow, and light regimes all have the potential to affect predator-prey encounters, yet the integration of these factors into our understanding of fish biomechanics is presently limited. We explore existing knowledge of kinematics, muscle function, hydrodynamics, and evolutionary morphology in order to generate a framework for understanding the ecomechanics of predator-prey encounters in fishes. We expect that, in the absence of behavioral compensation, a decrease in temperature below the optimum value will reduce the muscle power available both to predator and prey, thus compromising locomotor performance, suction-feeding mechanics of predators, and the escape responses of prey. Ambient flow, particularly turbulent flow, will also challenge predator and prey, perhaps resulting in faster attacks by predators to minimize mechanical instability, and a reduced responsiveness of prey to predator-generated flow. Reductions in visibility, caused by depth, turbidity, or diel fluctuations in light, will decrease distances at which either predator or prey detect each other, and generally place a greater emphasis on the role of mechanoreception both for predator and prey. We expect attack distances to be shortened when visibility is low. Ultimately, the variation in abiotic features of a fish's environment will affect locomotion and feeding performance of predators, and the ability of the prey to escape. The nature of these effects and how they impact predator-prey encounters stands as a major challenge for future students of the biomechanics of fish during feeding. Just as fishes show adaptations for capturing

  20. Adaption of suction connectors for use in meconium aspiration syndrome.

    PubMed

    Green, David Anthony

    2010-01-01

    Severe meconium aspiration syndrome is difficult to manage and has a high mortality in developing countries. Guidelines are available for the initial management. If the infant has been born through particulate meconium and is not vigorous, an inspection of the vocal cords by laryngoscopy is recommended. If meconium is seen at the cords it should, ideally, be sucked out of the trachea using an endotracheal tube as a suction device. However, as this needs a way of applying suction directly to the endotracheal tube it can be problematic. Commercially available equipment does exist, but in a resource-scarce setting, its cost could be prohibitive. We have adapted cheap suction connectors which can be adapted for this purpose.

  1. Safety System for Controlling Fluid Flow into a Suction Line

    NASA Technical Reports Server (NTRS)

    England, John Dwight (Inventor); Kelley, Anthony R. (Inventor); Cronise, Raymond J. (Inventor)

    2015-01-01

    A safety system includes a sleeve fitted within a pool's suction line at the inlet thereof. An open end of the sleeve is approximately aligned with the suction line's inlet. The sleeve terminates with a plate that resides within the suction line. The plate has holes formed therethrough. A housing defining a plurality of distinct channels is fitted in the sleeve so that the distinct channels lie within the sleeve. Each of the distinct channels has a first opening on one end thereof and a second opening on another end thereof. The second openings reside in the sleeve. Each of the distinct channels is at least approximately three feet in length. The first openings are in fluid communication with the water in the pool, and are distributed around a periphery of an area of the housing that prevents coverage of all the first openings when a human interacts therewith.

  2. Design considerations of advanced supercritical low drag suction airfoils

    NASA Technical Reports Server (NTRS)

    Pfenninger, W.; Reed, H. L.; Dagenhart, J. R.

    1980-01-01

    Supercritical low drag suction laminar flow airfoils were laid out for shock-free flow at design freestream Mach = 0.76, design lift coefficient = 0.58, and t/c = 0.13. The design goals were the minimization of suction laminarization problems and the assurance of shock-free flow at freestream Mach not greater than design freestream Mach (for design lift coefficient) as well as at lift coefficient not greater than design lift coefficient (for design freestream Mach); this involved limiting the height-to-length ratio of the supersonic zone at design to 0.35. High design freestream Mach numbers result with extensive supersonic flow (over 80% of the chord) on the upper surface, with a steep Stratford-type rear pressure rise with suction, as well as by carrying lift essentially in front- and rear-loaded regions of the airfoil with high static pressures on the carved out front and rear lower surface.

  3. Cohesive suction-cup force in cell separation dynamics

    NASA Astrophysics Data System (ADS)

    Vasseur, H.

    2010-07-01

    When an external pulling force is applied onto a cell stuck to its substrate, a reacting "suction-cup" force, due to the slow penetration of the surrounding fluid between the cell and the substrate, opposes to the separation. It can overcome other known adhesive forces when the process is sufficiently violent (typically 105 N/m2). The physical origin of this effect may be compared with that leaning a suction-cup against a bathroom wall. We address the consequences of this effect on i) the separation energy, ii) the fluid motion surrounding the cell, and iii) the inhibition of cell motion.

  4. A PHYSIOLOGICALLY BASED TOXICOKINETIC MODEL FOR DIETARY UPTAKE OF HYDROPHOBIC ORGANIC COMPOUNDS BY FISH: I. FEEDING STUDIES WITH 2,2',5,5'-TETRACHLOROBIPHENYL

    EPA Science Inventory

    A physiologically-based toxicokinetic (PBTK) model was developed to describe dietary uptake of hydrophobic organic compounds by fish. The gastrointestinal (GI) tract was modeled using four compartments corresponding to the stomach, pyloric ceca, upper intestine, and lower intesti...

  5. Protein nutrition in fish: protein/energy ratio and alternative protein sources to fish meal.

    PubMed

    Sanz, A; García Gallego, M; De la Higuera, M

    2000-09-01

    Those interested in the design and manufacture of feeds for intensive fish farming face the basic concern of formulating mixtures for the best yield at the lowest costs. Of the macronutrients in the feed, protein has and continues to receive special consideration because fish present high and specific needs for this constituent. Traditionally, protein has been supplied primarily by fish meals. This paper presents a synthesis of the efforts made and the lines explored to achieve an effective reduction of the amount of fish meal in the feeds for fish, following two strategies: reduction of the protein in the feeds and the use of new raw materials to replace fish meal.

  6. Feeding mechanics and bite force modelling of the skull of Dunkleosteus terrelli, an ancient apex predator.

    PubMed

    Anderson, Philip S L; Westneat, Mark W

    2007-02-22

    Placoderms are a diverse group of armoured fishes that dominated the aquatic ecosystems of the Devonian Period, 415-360 million years ago. The bladed jaws of predators such as Dunkleosteus suggest that these animals were the first vertebrates to use rapid mouth opening and a powerful bite to capture and fragment evasive prey items prior to ingestion. Here, we develop a biomechanical model of force and motion during feeding in Dunkleosteus terrelli that reveals a highly kinetic skull driven by a unique four-bar linkage mechanism. The linkage system has a high-speed transmission for jaw opening, producing a rapid expansion phase similar to modern fishes that use suction during prey capture. Jaw closing muscles power an extraordinarily strong bite, with an estimated maximal bite force of over 4400 N at the jaw tip and more than 5300 N at the rear dental plates, for a large individual (6 m in total length). This bite force capability is the greatest of all living or fossil fishes and is among the most powerful bites in animals.

  7. Dual-durometer soft suction foot robot for concrete inspection

    NASA Astrophysics Data System (ADS)

    Huston, Dryver; Burns, Dylan; Gardner-Morse, John; Montane, Paul; Angola, Enrique

    2014-03-01

    Climbing on concrete, masonry and brick with automated machines is difficult due to the uneven surfaces that prevent getting a good grip. This paper describes developments in using dual-durometer pneumatic suction feet for gripping onto concrete surfaces as part of a multi-legged robotic climbing system for inspecting concrete structures with vertical walls. The dual durometer technique presents a compliant suction tip to the concrete thereby producing a good seal against an irregular surface, and stiff component to deliver the structural rigidity needed for walking and climbing. Individually actuated pneumatic Venturi vacuum generators provide the suction from positive pneumatic pressure in a manner that is robust against leaks that cause the systemic vacuum collapse that can plague other vacuum configurations. The feet are attached to a six-legged robot that with a nominal floor walking capability and gait. Climbing a wall requires modification to leg actuation and gait, along with suction feet. System design, integration, concrete wall climbing performance and sensor deployment in the form of a lightweight ground penetrating radar system are presented.

  8. Teaching Self-Administration of Suctioning to Children with Tracheostomies.

    ERIC Educational Resources Information Center

    Derrickson, Janice G.; And Others

    1991-01-01

    Four children (ages 5-8) with tracheostomies were taught to self-administer a suctioning procedure via doll-centered simulations. Performance of all children improved as a function of training; skill maintenance was demonstrated during followup; and participants revealed high levels of satisfaction with outcomes. (Author/JDD)

  9. Premaxillary movements in cyprinodontiform fishes: an unusual protrusion mechanism facilitates "picking" prey capture.

    PubMed

    Ferry-Graham, Lara A; Gibb, Alice C; Hernandez, L Patricia

    2008-01-01

    Premaxillary protrusion is hypothesized to confer a number of feeding advantages to teleost fishes; however, most proposed advantages relate to enhanced stealth or suction production during prey capture. Cyprinodontiformes exhibit an unusual form of premaxillary protrusion where the descending process of the premaxilla does not rotate anteriorly to occlude the sides of the open mouth during prey capture. Instead, the premaxilla is protruded such that it gives the impression of a beak during prey capture. We quantified premaxillary kinematics during feeding in four cyprinodontiform taxa and compared them with three percomorph taxa to identify any performance consequences of this protrusion mechanism. Individual prey capture events were recorded using digital high-speed video at 250-500 frames per second (n >or= 4 individuals, >or= 4 strikes per individual). Species differed in the timing of movement and the maximum displacement of the premaxilla during the gape cycle and in the contribution of the premaxilla to jaw closing. Cyprinodontiform taxa produced less premaxillary protrusion than the percomorph taxa, and were consistently slower in the time to maximum gape. Further, it appears cyprinodontiforms can alter the contribution of the premaxilla to mouth closure on an event-specific basis. We were able to demonstrate that, within at least one species, this variability is associated with the location of the prey (bottom vs. water column). Cyprinodontiform upper jaw movements likely reflect increased dexterity associated with a foraging ecology where prey items are "picked" from a variety of locations: the bottom, water column, or surface. We postulate that dexterity requires slow, precisely controlled jaw movements; thus, may be traded off for some aspects of suction-feeding performance, such as protrusion distance and speed. PMID:18619823

  10. Stable isotopes as a useful tool for revealing the environmental fate and trophic effect of open-sea-cage fish farm wastes on marine benthic organisms with different feeding guilds.

    PubMed

    Wai, Tak-Cheung; Leung, Kenneth M Y; Wu, Rudolf S S; Shin, Paul K S; Cheung, S G; Li, X Y; Lee, Joseph H W

    2011-01-01

    Environmental fate of fish farm wastes (FFW) released from an open-sea-cage farm at Kat O, Hong Kong was examined by measuring carbon and nitrogen stable isotope (SI) ratios in selected benthic organisms collected along a 2000 m transect from the farm. Our results showed that FFW significantly influenced the energy utilization profile of consumers near the fish farm. Although nitrogen enrichment effect on δ15N was anticipated in biota near the farm, the predicted patterns did not consistently occur in all feeding guilds. Two species of suspension-feeders, which relied on naturally δ15N-depleted sources, were δ15N-enriched near the fish farm. In contrast, both species of benthic grazer and deposit-feeder, which relied on naturally δ15N-enriched algal sources, were δ15N-depleted under the influence of FFW. The SI signatures of biota can, therefore, serve as feasible biomarkers for FFW discharges only when the trophic structure of the receiving environment is fully elucidated. PMID:21641622

  11. Stable isotopes as a useful tool for revealing the environmental fate and trophic effect of open-sea-cage fish farm wastes on marine benthic organisms with different feeding guilds.

    PubMed

    Wai, Tak-Cheung; Leung, Kenneth M Y; Wu, Rudolf S S; Shin, Paul K S; Cheung, S G; Li, X Y; Lee, Joseph H W

    2011-01-01

    Environmental fate of fish farm wastes (FFW) released from an open-sea-cage farm at Kat O, Hong Kong was examined by measuring carbon and nitrogen stable isotope (SI) ratios in selected benthic organisms collected along a 2000 m transect from the farm. Our results showed that FFW significantly influenced the energy utilization profile of consumers near the fish farm. Although nitrogen enrichment effect on δ15N was anticipated in biota near the farm, the predicted patterns did not consistently occur in all feeding guilds. Two species of suspension-feeders, which relied on naturally δ15N-depleted sources, were δ15N-enriched near the fish farm. In contrast, both species of benthic grazer and deposit-feeder, which relied on naturally δ15N-enriched algal sources, were δ15N-depleted under the influence of FFW. The SI signatures of biota can, therefore, serve as feasible biomarkers for FFW discharges only when the trophic structure of the receiving environment is fully elucidated.

  12. 21 CFR 880.6740 - Vacuum-powered body fluid suction apparatus.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Vacuum-powered body fluid suction apparatus. 880... Personal Use Miscellaneous Devices § 880.6740 Vacuum-powered body fluid suction apparatus. (a) Identification. A vacuum-powered body fluid suction apparatus is a device used to aspirate, remove, or...

  13. 21 CFR 880.6740 - Vacuum-powered body fluid suction apparatus.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Vacuum-powered body fluid suction apparatus. 880... Personal Use Miscellaneous Devices § 880.6740 Vacuum-powered body fluid suction apparatus. (a) Identification. A vacuum-powered body fluid suction apparatus is a device used to aspirate, remove, or...

  14. 21 CFR 880.6740 - Vacuum-powered body fluid suction apparatus.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Vacuum-powered body fluid suction apparatus. 880... Personal Use Miscellaneous Devices § 880.6740 Vacuum-powered body fluid suction apparatus. (a) Identification. A vacuum-powered body fluid suction apparatus is a device used to aspirate, remove, or...

  15. 21 CFR 880.6740 - Vacuum-powered body fluid suction apparatus.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Vacuum-powered body fluid suction apparatus. 880... Personal Use Miscellaneous Devices § 880.6740 Vacuum-powered body fluid suction apparatus. (a) Identification. A vacuum-powered body fluid suction apparatus is a device used to aspirate, remove, or...

  16. 21 CFR 880.6740 - Vacuum-powered body fluid suction apparatus.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Vacuum-powered body fluid suction apparatus. 880... Personal Use Miscellaneous Devices § 880.6740 Vacuum-powered body fluid suction apparatus. (a) Identification. A vacuum-powered body fluid suction apparatus is a device used to aspirate, remove, or...

  17. Feeding mice with diets containing mercury-contaminated fish flesh from French Guiana: a model for the mercurial intoxication of the Wayana Amerindians

    PubMed Central

    Bourdineaud, Jean-Paul; Bellance, Nadège; Bénard, Giovani; Brèthes, Daniel; Fujimura, Masatake; Gonzalez, Patrice; Marighetto, Aline; Maury-Brachet, Régine; Mormède, Cécile; Pédron, Vanessa; Philippin, Jean-Nicolas; Rossignol, Rodrigue; Rostène, William; Sawada, Masumi; Laclau, Muriel

    2008-01-01

    Background In 2005, 84% of Wayana Amerindians living in the upper marshes of the Maroni River in French Guiana presented a hair mercury concentration exceeding the limit set up by the World Health Organization (10 μg/g). To determine whether this mercurial contamination was harmful, mice have been fed diets prepared by incorporation of mercury-polluted fish from French Guiana. Methods Four diets containing 0, 0.1, 1, and 7.5% fish flesh, representing 0, 5, 62, and 520 ng methylmercury per g, respectively, were given to four groups of mice for a month. The lowest fish regimen led to a mercurial contamination pressure of 1 ng mercury per day per g of body weight, which is precisely that affecting the Wayana Amerindians. Results The expression of several genes was modified with mercury intoxication in liver, kidneys, and hippocampus, even at the lowest tested fish regimen. A net genetic response could be observed for mercury concentrations accumulated within tissues as weak as 0.15 ppm in the liver, 1.4 ppm in the kidneys, and 0.4 ppm in the hippocampus. This last value is in the range of the mercury concentrations found in the brains of chronically exposed patients in the Minamata region or in brains from heavy fish consumers. Mitochondrial respiratory rates showed a 35–40% decrease in respiration for the three contaminated mice groups. In the muscles of mice fed the lightest fish-containing diet, cytochrome c oxidase activity was decreased to 45% of that of the control muscles. When mice behavior was assessed in a cross maze, those fed the lowest and mid-level fish-containing diets developed higher anxiety state behaviors compared to mice fed with control diet. Conclusion We conclude that a vegetarian diet containing as little as 0.1% of mercury-contaminated fish is able to trigger in mice, after only one month of exposure, disorders presenting all the hallmarks of mercurial contamination. PMID:18959803

  18. The relative importance of mangroves and seagrass beds as feeding habitats for resident and transient fishes from Florida and Belize:: evidence from dietary and stable isotope analyses

    EPA Science Inventory

    In the western Atlantic region, the contribution of mangrove food-sources to fish diets has been considered of more limited importance then previously expected due to their constant flooding and proximity to adjacent coastal habitats such as seagrass beds which provide potential ...

  19. Feeding kinematics and performance of basal otariid pinnipeds, Steller sea lions and northern fur seals: implications for the evolution of mammalian feeding.

    PubMed

    Marshall, Christopher D; Rosen, David A S; Trites, Andrew W

    2015-10-01

    Feeding performance studies can address questions relevant to feeding ecology and evolution. Our current understanding of feeding mechanisms for aquatic mammals is poor. Therefore, we characterized the feeding kinematics and performance of five Steller sea lions (Eumetopias jubatus) and six northern fur seals (Callorhinus ursinus). We tested the hypotheses that both species use suction as their primary feeding mode, and that rapid jaw opening was related to suction generation. Steller sea lions used suction as their primary feeding mode, but also used a biting feeding mode. In contrast, northern fur seals only used a biting feeding mode. Kinematic profiles of Steller sea lions were all indicative of suction feeding (i.e. a small gape, small gape angle, large depression of the hyolingual apparatus and lip pursing). However, jaw opening as measured by gape angle opening velocity (GAOV) was relatively slow in Steller sea lions. In contrast to Steller sea lions, the GAOV of northern fur seals was extremely fast, but their kinematic profiles indicated a biting feeding mode (i.e. northern fur seals exhibited a greater gape, a greater gape angle and minimal depression of the hyolingual apparatus compared with Steller sea lions). Steller sea lions produced both subambient and suprambient pressures at 45 kPa. In contrast, northern fur seals produced no detectable pressure measurements. Steller sea lions have a broader feeding repertoire than northern fur seals, which likely enables them to feed on a greater variety of prey, in more diverse habitats. Based on the basal phylogenetic position of northern fur seals, craniodental morphological data of the Callorhinus lineage, and the performance data provided in this study, we suggest that northern fur seals may be exhibiting their ancestral feeding mode.

  20. Feeding kinematics and performance of basal otariid pinnipeds, Steller sea lions and northern fur seals: implications for the evolution of mammalian feeding.

    PubMed

    Marshall, Christopher D; Rosen, David A S; Trites, Andrew W

    2015-10-01

    Feeding performance studies can address questions relevant to feeding ecology and evolution. Our current understanding of feeding mechanisms for aquatic mammals is poor. Therefore, we characterized the feeding kinematics and performance of five Steller sea lions (Eumetopias jubatus) and six northern fur seals (Callorhinus ursinus). We tested the hypotheses that both species use suction as their primary feeding mode, and that rapid jaw opening was related to suction generation. Steller sea lions used suction as their primary feeding mode, but also used a biting feeding mode. In contrast, northern fur seals only used a biting feeding mode. Kinematic profiles of Steller sea lions were all indicative of suction feeding (i.e. a small gape, small gape angle, large depression of the hyolingual apparatus and lip pursing). However, jaw opening as measured by gape angle opening velocity (GAOV) was relatively slow in Steller sea lions. In contrast to Steller sea lions, the GAOV of northern fur seals was extremely fast, but their kinematic profiles indicated a biting feeding mode (i.e. northern fur seals exhibited a greater gape, a greater gape angle and minimal depression of the hyolingual apparatus compared with Steller sea lions). Steller sea lions produced both subambient and suprambient pressures at 45 kPa. In contrast, northern fur seals produced no detectable pressure measurements. Steller sea lions have a broader feeding repertoire than northern fur seals, which likely enables them to feed on a greater variety of prey, in more diverse habitats. Based on the basal phylogenetic position of northern fur seals, craniodental morphological data of the Callorhinus lineage, and the performance data provided in this study, we suggest that northern fur seals may be exhibiting their ancestral feeding mode. PMID:26449976

  1. Compressor bleed cooling fluid feed system

    DOEpatents

    Donahoo, Eric E; Ross, Christopher W

    2014-11-25

    A compressor bleed cooling fluid feed system for a turbine engine for directing cooling fluids from a compressor to a turbine airfoil cooling system to supply cooling fluids to one or more airfoils of a rotor assembly is disclosed. The compressor bleed cooling fluid feed system may enable cooling fluids to be exhausted from a compressor exhaust plenum through a downstream compressor bleed collection chamber and into the turbine airfoil cooling system. As such, the suction created in the compressor exhaust plenum mitigates boundary layer growth along the inner surface while providing flow of cooling fluids to the turbine airfoils.

  2. Ontogenetic differences in the feeding biomechanics of oviparous and viviparous caecilians (Lissamphibia: Gymnophiona).

    PubMed

    Kleinteich, Thomas

    2010-10-01

    Caecilians have a unique dual jaw-closing system in that jaw closure is driven by the ancestral jaw-closing muscles (mm. levatores mandibulae) plus a secondarily recruited hyobranchial muscle (m. interhyoideus posterior). There is a variety of feeding habits (suction feeding, skin feeding, intrauterine scraping, and biting) during ontogeny that relate to reproductive modes in different caecilian species. This study examines the cranial biomechanics of caecilians in the suction-feeding larva of Ichthyophis cf. kohtaoensis, in the embryo and juvenile of the skin-feeding Boulengerula taitana, and in a newborn of the intrauterine feeder Typhlonectes natans. A lever arm model was applied to calculate effective mechanical advantages of jaw-closing muscles over gape angles and to predict total bite force in developing caecilians. In I. cf. kohtaoensis, Notable differences were found in the larval jaw-closing system compared to that of the adult. The suction-feeding larva of I. cf. kohtaoensis has comparatively large mm. levatores mandibulae that insert with an acute muscle fiber angle to the lower jaw and a m. interhyoideus posterior that has its optimal leverage at small gape angles. Conversely, the skin-feeding juvenile of B. taitana and the neonate T. natans are very similar in the feeding parameters considered herein compared to adult caecilians. Some ontogenetic variation in the feeding system of B. taitana before the onset of feeding was present. This study contributes to our understanding of the functional demands that feeding habits put on the development of cranial structures.

  3. Ontogenetic differences in the feeding biomechanics of oviparous and viviparous caecilians (Lissamphibia: Gymnophiona).

    PubMed

    Kleinteich, Thomas

    2010-10-01

    Caecilians have a unique dual jaw-closing system in that jaw closure is driven by the ancestral jaw-closing muscles (mm. levatores mandibulae) plus a secondarily recruited hyobranchial muscle (m. interhyoideus posterior). There is a variety of feeding habits (suction feeding, skin feeding, intrauterine scraping, and biting) during ontogeny that relate to reproductive modes in different caecilian species. This study examines the cranial biomechanics of caecilians in the suction-feeding larva of Ichthyophis cf. kohtaoensis, in the embryo and juvenile of the skin-feeding Boulengerula taitana, and in a newborn of the intrauterine feeder Typhlonectes natans. A lever arm model was applied to calculate effective mechanical advantages of jaw-closing muscles over gape angles and to predict total bite force in developing caecilians. In I. cf. kohtaoensis, Notable differences were found in the larval jaw-closing system compared to that of the adult. The suction-feeding larva of I. cf. kohtaoensis has comparatively large mm. levatores mandibulae that insert with an acute muscle fiber angle to the lower jaw and a m. interhyoideus posterior that has its optimal leverage at small gape angles. Conversely, the skin-feeding juvenile of B. taitana and the neonate T. natans are very similar in the feeding parameters considered herein compared to adult caecilians. Some ontogenetic variation in the feeding system of B. taitana before the onset of feeding was present. This study contributes to our understanding of the functional demands that feeding habits put on the development of cranial structures. PMID:20952171

  4. On equations for the total suction and its matric and osmotic components

    SciTech Connect

    Dao, Vinh N.T. Morris, Peter H.; Dux, Peter F.

    2008-11-15

    A clear fundamental understanding of suctions is crucial for the study of the behaviour of plastic cement mortar and concrete, including plastic shrinkage cracking. In this paper, the expression relating the change in free energy of the pore water with an isothermal change in pressure is first derived. Based upon definitions of suctions, it is then shown that total, matric, and osmotic suctions can all be expressed in the same thermodynamic form. The widely accepted, but not yet satisfactorily validated, assumption that the total suction comprises matric and osmotic components is then confirmed theoretically. The well-known Kelvin equation for matric suction, and Morse and van't Hoff equations for osmotic suction are subsequently derived from the corresponding thermodynamic equations. The applicability of latter two equations in evaluating the osmotic suctions of cement mortar and concrete is highlighted.

  5. Trophic relationships, feeding habits and seasonal dietary changes in an intertidal rockpool fish assemblage in the Gulf of Cadiz (NE Atlantic)

    NASA Astrophysics Data System (ADS)

    Compaire, Jesus C.; Cabrera, Remedios; Gómez-Cama, Carmen; Soriguer, Milagrosa C.

    2016-06-01

    This paper describes the use of resources and diet of nine resident fish species in the rocky intertidal zone of the Gulf of Cadiz and examines whether their populations are affected by trophic competition. A stomach content analysis of the nine species revealed that only one was herbivorous (Parablennius sanguinolentus), while the rest were mainly carnivorous (Gobius bucchichi, Gobius cobitis, Gobius paganellus, Zebrus zebrus, Salaria pavo, Lepadogaster lepadogaster, Scorpaena porcus and Tripterygion tripteronotum). The most frequently consumed prey were amphipods, isopods, polychaetes, decapods, chironomids, tanaidaceans, gastropods, copepods, cumaceans and ostracods. In most species, the occurrence of polychaetes and molluscs was higher in the cold season, whereas that of isopods, decapods, chironomids and fish increased in the warm season. In general, larger specimens consumed larger prey, with an increase in the occurrence of isopods, decapods and fish. An analysis of trophic niche breadth defined G. cobitis as generalist, G. bucchichi as opportunist and S. porcus as specialist, whereas the values obtained for the other species did not indicate a clearly defined strategy. Low diet overlap values and the segregation observed in several analyses indicated an adequate distribution of resources.

  6. Suction blister skin grafting--a modern application.

    PubMed

    Parbhoo, A V; Simpson, M T

    2014-03-01

    The suction blistering technique produces an ultra-thin skin graft with no morbidity at the donor site. Negative pressure using wall suction in outpatients is used to generate a graft that can be used for reconstruction, and it avoids the need for invasive procedures in patients with coexisting conditions. The harvested tissue has a low metabolic demand and survival is excellent. We used it in a patient when previous reconstructions after excision of skin cancer had failed. Graft survival was more than 95% by surface area and there was no donor site morbidity. We have found it particularly useful for grafting over Integra® dermal regeneration template (Integra LifeSciences Corporation, NJ, USA) to produce healing at difficult sites. Patients tolerate the procedure well and the donor site heals quickly. It is useful where recipient vascularity is poor or where coexisting conditions prevent complex procedures.

  7. Postinflammatory depigmentation: excellent results with suction blister grafting.

    PubMed

    Suthar, Chandanmal; Gupta, Somesh; Kathuria, Sushruta

    2010-11-01

    Depigmentation over the face of young females is usually not acceptable from an Indian social perspective. We are reporting a case of postinflammatory depigmentation over face of young female that was successfully treated. The patient developed depigmentation following inflammation as a result of a local application. She underwent three sessions of epidermal suction blister grafting with PUVA therapy instituted after the grafting to assist in the spreading of the pigmentation. First two sitting resulted in total repigmentation. She underwent a third sitting recently. Pigment spread is continuing with PUVA therapy in the area of the third session. The patient is satisfied with the outcome. In conclusion, we suggest that suction blister epidermal grafting can be tried in the treatment of postinflammatory depigmentation.

  8. Prolonged suction drainage prevents serous wound discharge after cardiac surgery.

    PubMed

    Kockelbergh, R C; Harris, A M; John, R M; Bailey, J S; Firmin, R K

    1994-01-01

    A series of 180 patients was randomised to two groups after median sternotomy performed for cardiac surgery in order to evaluate the effect of suction drainage on serous wound discharge. In group A all wounds were drained using two conventional mediastinal drains, while in group B one suction drain and one conventional mediastinal drain were employed. Five patients developed serous wound discharge in group B compared with 14 in group A (chi 2, P < 0.02). There were no significant differences between the rates of major wound infection (group A, n = 1; group B, n = 1) or the incidence of postoperative pericardial effusion assessed by echocardiography (group A, n = 10; group B, n = 5).

  9. Stability of flow over axisymmetric bodies with porous suction strips

    NASA Technical Reports Server (NTRS)

    Nayfeh, A. H.; Reed, H. L.

    1982-01-01

    Linear triple deck, closed form solutions for mean-flow quantities are developed for axisymmetric incompressible flow past a body with porous strips. The solutions account for upstream influence and are linear superpositions of the flow past the body without suction plus the perturbations due to the suction strips. Flow past the suctionless body is calculated using the Transition Analysis Program System, and a simple linear optimization scheme to determine number, spacing, and mass flow rate through the strips on an axisymmetric body is developed using the linear, triple-deck, closed-form solutions. The theory is demonstrated by predicting optimal strip distributions, and the effect of various adverse pressure-gradient situations on stability is studied.

  10. Evaluation of Karl Storz CMAC Tip™ Device Versus Traditional Airway Suction in a Cadaver Model

    PubMed Central

    Lipe, Demis N.; Lindstrom, Randi; Tauferner, Dustin; Mitchell, Christopher; Moffett, Peter

    2014-01-01

    Introduction We compared the efficacy of Karl Storz CMAC Tip™ with inline suction to CMAC with traditional suction device in cadaveric models simulating difficult airways, using media mimicking pulmonary edema and vomit. Methods This was a prospective, cohort study in which we invited emergency medicine faculty and residents to participate. Each participant intubated 2 cadavers (one with simulated pulmonary edema and one with simulated vomit), using CMAC with inline suction and CMAC with traditional suction. Thirty emergency medicine providers performed 4 total intubations each in a crossover trial comparing the CMAC with inline suction and CMAC with traditional suction. Two intubations were performed with simulated vomit and two with simulated pulmonary edema. The primary outcome was time to successful intubation; and the secondary outcome was proportion of successful intubation. Results The median time to successful intubation using the CMAC with inline suction versus traditional suction in the pulmonary edema group was 29s and 30s respectively (p=0.54). In the vomit simulation, the median time to successful intubation was 40s using the CMAC with inline suction and 41s using the CMAC with traditional suction (p=0.70). There were no significant differences in time to successful intubation between the 2 devices. Similarly, the proportions of successful intubation were also not statistically significant between the 2 devices. The proportions of successful intubations using the inline suction were 96.7% and 73.3%, for the pulmonary edema and vomit groups, respectively. Additionally using the handheld suction device, the proportions for the pulmonary edema and vomit group were 100% and 66.7%, respectively. Conclusion CMAC with inline suction was no different than CMAC with traditional suction and was associated with no statistically significant differences in median time to intubation or proportion of successful intubations. PMID:25035766

  11. Intermittent patient suction system, self-contained control

    DOEpatents

    Lewis, Jay L.

    1992-01-01

    An intermittent patient suction system, a self-contained control device therefor and methods of making the same are provided, the self-contained control device having a housing that contains two restrictor units therein for respectively controlling the "on" time and "off" time that the control device applies a vacuum and does not apply a vacuum through the output of the control device to the patient.

  12. Development of a laminar boundary layer behind a suction point

    NASA Technical Reports Server (NTRS)

    Wuest, Walter

    1952-01-01

    A theoretical investigation is made of the development of a laminar boundary layer behind a suction slot that is assumed to cut off part of the boundary layer without exerting any sink effect. The development, which is approximate, is based on the heat conduction equation. The heat conduction equation enters the analysis through a linearization of the Prandtl-Mises form of the boundary-layer equation.

  13. Making Large Suction Panels For Laminar-Flow Control

    NASA Technical Reports Server (NTRS)

    Maddalon, Dal V.

    1991-01-01

    Perforated titanium panels used to identify and resolve issues related to manufacture. Recently, relatively large suction panels with aerodynamically satisfactory surface perforations and with surface contours and smoothness characteristics necessary for Laminar-Flow Control (LFC) designed, fabricated, and tested. Requirements of production lines for commercial transport airplanes carefully considered in development of panels. Sizes of panels representative of what is used on wing of commercial transport airplane. Tests of perforated panels in transonic wind tunnel demonstrated aerodynamic stability at flight mach numbers.

  14. Approximation theory for boundary layer suction through individual slits

    NASA Technical Reports Server (NTRS)

    Walz, A.

    1979-01-01

    The basic concepts of influencing boundary layers are summarized, especially the prevention of flow detachment and the reduction of frictional resistance. A mathematical analysis of suction through a slit is presented with two parameters, for thickness and for shape of the boundary layer, being introduced to specify the flow's velocity profile behind the slit. An approximation of the shape parameter produces a useful formula, which can be used to determine the most favorable position of the slit. An aerodynamic example is given.

  15. Effect of wall suction on the stability of compressible subsonic flows over smooth two-dimensional backward-facing steps

    NASA Technical Reports Server (NTRS)

    Al-Maaitah, Ayman A.; Nayfeh, Ali H.; Ragab, Saad A.

    1989-01-01

    The effect of suction on the stability of compressible flows over backward-facing steps is investigated. Mach numbers up to 0.8 are considered. The results show that continuous suction stabilizes the flow outside the separation bubble, but it destabilizes the flow inside it. Nevertheless, the overall N factor decreases as the suction level increases due to the considerable reduction of the separation bubble. For the same suction flow rate, properly distributed suction strips stabilize the flow more than continuous suction. The size of the separation bubble, and hence its effect on the instability can be considerably reduced by placing strips with high suction velocities in the separation region.

  16. Bioaccumulation of dioxin-like PCBs and PBDEs by detritus-feeding fish in the Rio de la Plata estuary, Argentina.

    PubMed

    Cappelletti, N; Speranza, E; Tatone, L; Astoviza, M; Migoya, M C; Colombo, J C

    2015-05-01

    A comparative analysis of bioaccumulation behavior of dioxin-like polychlorinated biphenyls (dlPCBs) and polybrominated biphenyl ethers (PBDEs) was conducted involving simultaneous measurements in settling particles and a detritivorous fish (Sabalo, Prochilodus linneatus) collected in the sewage impacted Buenos Aires coastal area. Focalization of dlPCBs and PBDEs along the detritus food chain is reflected by a 30-40-fold increase of dry weight PBDE and dlPCB concentrations from settling particles to fish (1.8 ± 1.0 to 58 ± 31 and 6.8 ± 3.9 to 281 ± 155 ng g(-1) dry weight (dw), respectively). In this transference, dlPCB congeners presented more conservative patterns than those of PBDEs, basically due to debromination of BDE 99 and 153 to BDE 47 in fish. Lipid/organic carbon-based biota-sediment accumulation factors (BSAFs) ranged between 5 and 20 (7.3 ± 3.0 and 16 ± 8.0 for PBDEs and dlPCBs). Congener-specific BSAF of dlPCBs suggested a lower bioavailability of more planar non-ortho-PCB versus mono-ortho-PCB suggesting higher affinity to organic matter. BSAFs of PBDEs differed markedly among bromine homolog groups, supporting the biotransformation-formation from higher brominated to lighter congeners. The log BSAFs-log K OW relationship of dlPCBs and PBDEs presented a parabolic pattern maximizing at log K OW 6-7, but PBDE curve differs reflecting biotransformation processes.

  17. Transcatheter radiofrequency ablation of atrial tissue using a suction catheter.

    PubMed

    Lavergne, T; Prunier, L; Cuize, L; Bruneval, P; Von Euw, D; Le Heuzey, J Y; Peronneau, P

    1989-01-01

    Closed chest ablative technique that avoid barotrauma would be attractive for ablation at thin walled cardiac structures, such as the atrial free wall or coronary sinus. Transcatheter radiofrequency (RF) currents produce tissue necrosis the size of which is dependent on the contact between the tissue and the electrode. In order to assess the effects of transvenous RF ablation of atrial free wall using a suction electrode catheter, we delivered in ten dogs, one single unmodulated RF pulse 1.2 MHz, in a unipolar mode, through the distal electrode of a lumen catheter (USCI 8F) (USCI, Billerica, MA USA) located in the right appendage. During the pulse an 80 KPa vacuum depression was applied to the lumen of the catheter. Each pulse had a 10 seconds duration and the mean delivered power was 4.3 +/- 1.4 W. Aortic pressure and electrocardiogram were monitored during the procedure. A right atrial electrophysiological study was performed at the ablated site, at control, after suction application and after RF pulse delivery. The animals were sacrificed after 14 or 21 days. Atrial pacing threshold values decreased after suction application in comparison to control values after the pulse (0.42 +/- 0.06 vs 0.60 +/- 0.23 mA, P less than O.05) but increased after the pulse delivery (2.60 +/- 1.85 mA, P less than 0.01). In contrast, the atrial effective refractory period did not significantly change after suction, nor after RF pulse delivery. Aortic pressure remained unchanged throughout the procedure. Complex arrhythmias were not observed during or after RF pulse delivery. One dog died suddenly at the first day after ablation, but this death was most probably unrelated to RF ablation. Anatomic lesions had a length of 8.8 +/- 3.3 mm, a width of 4.6 +/- 2.5 mm and a depth of 3.6 +/- 1.1 mm. They were transmural in nine of the ten dogs but without atrial wall perforation in any case. Lesions suggesting tissue volatilization were present in four dogs. These results demonstrate that

  18. Comparison the Effects of Shallow and Deep Endotracheal Tube Suctioning on Respiratory Rate, Arterial Blood Oxygen Saturation and Number of Suctioning in Patients Hospitalized in the Intensive Care Unit: A Randomized Controlled Trial

    PubMed Central

    Abbasinia, Mohammad; Irajpour, Alireza; Babaii, Atye; Shamali, Mehdi; Vahdatnezhad, Jahanbakhsh

    2014-01-01

    Introduction: Endotracheal tube suctioning is essential for improve oxygenation in the patients undergoing mechanical ventilation. There are two types of shallow and deep endotracheal tube suctioning. This study aimed to evaluate the effect of shallow and deep suctioning methods on respiratory rate (RR), arterial blood oxygen saturation (SpO2) and number of suctioning in patients hospitalized in the intensive care units of Al-Zahra Hospital, Isfahan, Iran. Methods: In this randomized controlled trial, 74 patients who hospitalized in the intensive care units of Isfahan Al-Zahra Hospital were randomly allocated to the shallow and deep suctioning groups. RR and SpO2 were measured immediately before, immediately after, 1 and 3 minute after each suctioning. Number of suctioning was also noted in each groups. Data were analyzed using repeated measures analysis of variance (RMANOVA), chi-square and independent t-tests. Results: RR was significantly increased and SpO2 was significantly decreased after each suctioning in the both groups. However, these changes were not significant between the two groups. The numbers of suctioning was significantly higher in the shallow suctioning group than in the deep suctioning group. Conclusion: Shallow and deep suctioning had a similar effect on RR and SpO2. However, shallow suctioning caused further manipulation of patient's trachea than deep suctioning method. Therefore, it seems that deep endotracheal tube suctioning method can be used to clean the airway with lesser manipulation of the trachea. PMID:25276759

  19. Effect of endotracheal suction on lung dynamics in mechanically-ventilated paediatric patients.

    PubMed

    Morrow, Brenda; Futter, Merle; Argent, Andrew

    2006-01-01

    Endotracheal suctioning is performed regularly in ventilated infants and children to remove obstructive secretions. The effect of suctioning on respiratory mechanics is not known. This study aimed to determine the immediate effect of endotracheal suctioning on dynamic lung compliance, tidal volume, and airway resistance in mechanically-ventilated paediatric patients by means of a prospective observational clinical study. Lung mechanics were recorded for five minutes before and five minutes after a standardised suctioning procedure in 78 patients intubated with endotracheal tubes < or = 4.0 mm internal diameter. Twenty-four patients with endotracheal tube leaks > or = 20% were excluded from analysis. There was a significant overall decrease in dynamic compliance (p < 0.001) and mechanical expired tidal volume (p = 0.03) following suctioning with no change in the percentage endotracheal tube leak (p = 0.41). The change in dynamic compliance was directly related to both endotracheal tube and catheter sizes. There was no significant change in expiratory or inspiratory airway resistance following suctioning (p > 0.05). Although the majority of patients (68.5%) experienced a drop in dynamic compliance following suctioning, dynamic compliance increased in 31.5% of patients after the procedure. This study demonstrates that endotracheal suctioning frequently causes an immediate drop in dynamic compliance and expired tidal volume in ventilated children with variable lung pathology, intubated with small endotracheal tubes, probably indicating loss of lung volume caused by the suctioning procedure. There is no evidence that suctioning reduces airway resistance.

  20. Numerical simulation of installation process and uplift resistance for an integrated suction foundation in deep ocean

    NASA Astrophysics Data System (ADS)

    Li, Ying; Yang, Shu-geng; Yu, Shu-ming

    2016-03-01

    A concept design, named integrated suction foundation, is proposed for a tension leg platform (TLP) in deep ocean. The most important improvement in comparing with the traditional one is that a pressure-resistant storage module is designed. It utilizes the high hydrostatic pressure in deep ocean to drive water into the module to generate negative pressure for bucket suction. This work aims to further approve the feasibility of the concept design in the aspect of penetration installation and the uplift force in-place. Seepage is generated during suction penetration, and can have both positive and negative effects on penetration process. To study the effect of seepage on the penetration process of the integrated suction foundation, finite element analysis (FEA) is carried out in this work. In particular, an improved methodology to calculate the penetration resistance is proposed for the integrated suction foundation with respect to the reduction factor of penetration resistance. The maximum allowable negative pressure during suction penetration is calculated with the critical hydraulic gradient method through FEA. The simulation results of the penetration process show that the integrated suction foundation can be installed safely. Moreover, the uplift resistance of the integrated suction foundation is calculated and the feasibility of the integrated suction foundation working on-site is verified. In all, the analysis in this work further approves the feasibility of the integrated suction foundation for TLPs in deep ocean applications.

  1. Broken Piece of Silicone Suction Catheter in Upper Alimentary Tract of a Neonate

    PubMed Central

    Saleem, Muhammad; Sheikh, Afzal

    2010-01-01

    Esophageal foreign bodies (FB) are common in adults and children. These are rarely reported in infants and neonates. A 2-day-old newborn was referred to our hospital with history of accidental intrusion of soft silicone suction catheter into the upper gastrointestinal tract (GIT). X-ray chest and abdomen confirmed the presence of suction tube in esophagus and stomach. The suction catheter was retrieved successfully at direct laryngoscopy. PMID:22953251

  2. Perforated Sheets as the Porous Material for a Suction-flap Application

    NASA Technical Reports Server (NTRS)

    Dannenberg, Robert E; Weiburg, James A; Gambucci, Bruno J

    1957-01-01

    Two-dimensional tests were made of an NACA 0006 airfoil with area suction applied to a porous region on a 0.3-chord trailing-edge flap deflected 50 degrees. The lift with suction approached the value computed from thin-airfoil theory. The lift gains and suction quantity requirements were unaffected by the perforation patterns of the surface over a wide range of hole sizes and spacings.

  3. Necessity of Surgical Site Closed Suction Drain for Pterional Craniotomy

    PubMed Central

    Choi, Su Yong; Yoon, Sung Min; Yoo, Chan Jong; Kim, Young Bo; Kim, Woo Kyung

    2015-01-01

    Objective The aim of this study was to assess the benefit of using a prophylactic surgical site closed suction drain in pterional craniotomy. Materials and Methods A retrospective review was conducted on 607 consecutive patients who underwent a pterional craniotomy for treatment of intracranial anterior circulation aneurysms over a 5-year period. Between January 2000 and December 2004, 607 patients were divided into two groups, those who had a prophylactic suction drain during closure of the surgical site (drain group, DG) and those who did not (non-drain group, NDG). Head computed tomography (CT) was taken routinely on postoperative day (POD) 1, 7, and 14. Patients' demographics, incidence of surgical site complications, and courses of surgical site healing which were evaluated radiologically by the thickness of the surgical site myocutaneous layer, were analyzed between DG and NDG. Results Patients' demographics and characteristics did not differ significantly between the two groups. The head CT showed that the degree of changes in the postoperative surgical site thickness was 148% at POD 1, 209% at POD 7, and 198% at POD 14 in DG, and 118% at POD 1, 152% at POD 7, and 158% at POD 14 in NDG compared to the preoperative value. Postoperative surgical site hematoma was 7.9% (22/274) in DG and 2.4% (8/333) in NDG. Conclusion Prophylactic use of an epidural and/or subgaleal closed suction drain does not appear to be necessary for prevention of postoperative surgical site hematoma as well as for promotion of surgical site healing in pterional craniotomy. PMID:26523255

  4. Pump tank divider plate for sump suction sodium pumps

    DOEpatents

    George, John A.; Nixon, Donald R.

    1977-01-01

    A circular plate extends across the diameter of "sump suction" pump, with a close clearance between the edge of the plate and the wall of the pump tank. The plate is located above the pump impeller, inlet and outlet flow nozzles but below the sodium free surface and effectively divides the pump tank into two separate chambers. On change of pump speed, the close fitting flow restriction plate limits the rate of flow into or out of the upper chamber, thereby minimizing the rate of level change in the tank and permitting time for the pump cover gas pressure to be varied to maintain an essentially constant level.

  5. Fat Harvest Using a Closed-Suction Drain

    PubMed Central

    Zakeri, Roxana; Mallucci, Patrick

    2016-01-01

    We propose a safe, simple, and novel method to harvest fat using a standard liposuction cannula and a Redivac or alternative closed-suction drain. The authors have used this technique for both 'dry' and 'wet' liposuction. This technique is both easy to perform and cost-effective whilst providing both a silent and relatively atraumatic fat harvest. The lower negative pressure compared with traditional harvesting systems likely preserves fat integrity for lipofilling. This method maximises resources already held within a hospital environment. PMID:27218029

  6. Motion compensation using a suctioning stabilizer for intravital microscopy

    PubMed Central

    Vinegoni, Claudio; Lee, Sungon; Gorbatov, Rostic; Weissleder, Ralph

    2013-01-01

    Motion artifacts continue to present a major challenge to single cell imaging in cardiothoracic organs such as the beating heart, blood vessels, or lung. In this study, we present a new water-immersion suctioning stabilizer that enables minimally invasive intravital fluorescence microscopy using water-based stick objectives. The stabilizer works by reducing major motion excursions and can be used in conjunction with both prospective or retrospective gating approaches. We show that the new approach offers cellular resolution in the beating murine heart without perturbing normal physiology. In addition, because this technique allows multiple areas to be easily probed, it offers the opportunity for wide area coverage at high resolution. PMID:24086796

  7. The effects of closed endotracheal suction on ventilation during conventional and high-frequency oscillatory ventilation.

    PubMed

    Kiraly, Nicholas J; Tingay, David G; Mills, John F; Morley, Colin J; Dargaville, Peter A; Copnell, Beverley

    2009-10-01

    In newborn infants, closed endotracheal tube (ETT) suction may reduce associated adverse effects, but it is not clear whether ventilation is maintained during the procedure. We aimed to determine the effect of ETT size, catheter size, and suction pressure on ventilation parameters measured distal to the ETT. Suction was performed on a test lung, ventilated with conventional (CMV) and high-frequency oscillatory ventilation (HFOV) using ETT sizes 2.5-4.0 mm, catheter sizes 5-8 French gauge (Fr), and suction pressures 80-200 mm Hg. Tracheal and circuit peak inspiratory pressure, positive end-expiratory pressure, and tracheal tidal volume (VT) were recorded for each suction episode. During both CMV and HFOV, tracheal pressures and VT were considerably reduced by suctioning; this reduction was dependent on the combination of ETT, catheter, and suction pressure. Loss of VT, inflation pressure (CMV), and pressure amplitude (HFOV) occurred primarily with insertion of the catheter, and loss of end-expiratory pressure (CMV) and mean tracheal pressure (HFOV) occurred with the application of suction. Circuit pressures were reduced to lesser degree. We conclude that airway pressures and VT are not maintained during closed endotracheal suction with either CMV or HFOV, and choice of equipment and settings will affect the degree of interruption to ventilation.

  8. Tree Water Uptake And Suction Distribution On Tropical Residual Soil Slope

    NASA Astrophysics Data System (ADS)

    Ishak, M. F.; Sulaiman, F. F.; Ali, N.; Kassim, A.

    2016-02-01

    This paper present an exploration of soil matric suction effected by water uptake via tree root at toe of slope on various condition between wet condition (high rainfall) and dry condition (prolonged no rainfall). Matric suction generated by active root tree has substantial influence soil moisture content on residual soil slope. A field monitoring was carried out to collect matric suction data at slope in two conditions; with a tree located at toe of slope and absent of a tree. The installations of instruments particularly at slope with tree at toe were placed within vicinity of the tree with certain depths and distances. The matric suction data from field monitoring was influence by the rainfall events that lead to the instability of soils slope. Analysis of soil matric suction distribution pattern indicates that the highest matric suction value was at shallower depth and proximity of tree. The matric suction profiles obtained from field monitoring are applied as an input data to develop soil matric suction contour. The effect of transpiration driven by active root zone generated matric suction on soil at vicinity of tree may create dry soil to increase soil shear strength.

  9. The NASA Langley laminar-flow-control experiment on a swept, supercritical airfoil: Suction coefficient analysis

    NASA Technical Reports Server (NTRS)

    Brooks, Cuyler W., Jr.; Harris, Charles D.; Harvey, William D.

    1991-01-01

    A swept supercritical wing incorporating laminar flow control at transonic flow conditions was designed and tested. The definition of an experimental suction coefficient and a derivation of the compressible and incompressible formulas for the computation of the coefficient from measurable quantities is presented. The suction flow coefficient in the highest velocity nozzles is shown to be overpredicted by as much as 12 percent through the use of an incompressible formula. However, the overprediction on the computed value of suction drag when some of the suction nozzles were operating in the compressible flow regime is evaluated and found to be at most 6 percent at design conditions.

  10. Comparing two levels of closed system suction pressure in ICU patients: Evaluating the relative safety of higher values of suction pressure

    PubMed Central

    Yazdannik, Ahmad R.; Haghighat, Somayeh; Saghaei, Mahmoud; Eghbali, Maryam

    2013-01-01

    Background: Endotracheal suctioning (ETS) is one of the most common supportive measures in intensive care units (ICU). ETS may be associated with complications including hypoxia and tachycardia. Closed system suctioning (CSS) decreases the rate of cardiorespiratory complication mainly due to continuation of ventilatory support and oxygenation during procedure. CSS has questionable efficacy, therefore higher values of negative pressure has been recommended to enhance the efficacy of CSS. This study was designed to evaluate the effects on gas exchange of 200 mmHg suctioning pressure compared with 100 mmHg in CSS. Materials and Methods: Fifty mechanically ventilated (MV) ICU patients were selected for the study. Two consecutive ten seconds CSS using suction pressures of 100 and 200 mmHg, in random order applied in each subject with the two hours wash out period. Effects of two levels of suction pressure on gas exchange were measured by recording the SPo2 values at 4 times. Results: Repeated measure analysis of variance didn't show any significant difference between two levels of pressure (P = 0.315), but within each groups (100 and 200 mmHg) SPO2 changes was significant (P = 0.000). There was a mild but significant and transient increase in heart rate following both suction pressures, but no significant difference between two groups. Conclusion: The results show that CSS with suction pressure 200 mmHg has no detrimental effect on cardiorespiratory function of MV ICU patients. Since the safety of 200 mmHg suctioning pressure was approved, using 200 mmHg suction pressures is recommended for ETS of MV patients. PMID:23983740

  11. Use of a Yankauer suction tip combined with the Colpo-Pneumo Occluder balloon to suction the surgical field at the vaginal cuff during robotic hysterectomy.

    PubMed

    Stitely, Michael L; Hashmi, Mahreen; Jain, Preiya; Hochberg, Charles

    2011-01-01

    A 39-year-old patient with complex endometrial hyperplasia without atypia underwent robotic total laparoscopic hysterectomy with bilateral salpingo-oophorectomy. The procedure was technically challenging because of the patient's obesity (body mass index 50 kg/m(2)). Concomitant suction of pooled blood and retraction of bowel and omentum were necessary to close the vaginal cuff. An endoscopic retractor was used through the assistant's port, and a Yankauer suction tip was placed through an inflated Colpo-Pneumo Occluder balloon in the vagina to provide directed suction to the vagina cuff. This technique enabled efficient closure of the vaginal cuff.

  12. Effects of suction-dredging for cockles on non-target fauna in the Wadden Sea [rapid communication

    NASA Astrophysics Data System (ADS)

    Hiddink, J. G.

    2003-12-01

    Suction dredging for cockles removes large cockles from tidal flats and may also cause mortality of non-target fauna and make the habitat less suitable for some species. This study examines whether suction dredging for cockles on tidal flats of the Dutch Wadden Sea had affected densities of non-target fauna, directly after fishing and one year later. Densities of non-target fauna in two randomly chosen undredged locations were compared to densities at the surrounding heavily commercially dredged area. A significant negative effect of cockle dredging on densities of 0-group Macoma balthica was observed and this effect persisted one year after dredging. The dredged area appeared to be less suitable for settlement of mussels Mytilus edulis. No significant effects of dredging on the mudsnail Hydrobia ulvae and on 0 and 1-group C. edule were found. For the mobile young Macoma balthica it seems unlikely that the effect found after one year was still due to the mortality caused by dredging and this suggests that the habitat was less suitable as a consequence of dredging. Thus, even in the highly dynamic ecosystem of the Wadden Sea, effects of bottom disturbance by cockle dredging may persist after one year.

  13. Acute IOP elevation with scleral suction: effects on retrobulbar haemodynamics.

    PubMed Central

    Harris, A; Joos, K; Kay, M; Evans, D; Shetty, R; Sponsel, W E; Martin, B

    1996-01-01

    AIMS/BACKGROUND: Mechanical and vascular factors may both contribute to glaucoma. This study investigated the relation of mechanical to vascular factors by examining how acute IOP elevation altered flow velocities in the central retinal and ophthalmic arteries. METHODS: IOP was elevated from a baseline near 14 to approximately 45 mm Hg using suction ophthalmodynamometry. During recovery from scleral suction, IOP fell to near 8 mm Hg. At each IOP, peak systolic and end diastolic velocities (PSV and EDV) were measured in the central retinal and ophthalmic arteries using colour Doppler imaging (Siemens Quantum 2000). Eleven healthy people served as subjects. RESULTS: Acute elevation in IOP had no effect upon PSV, EDV, or the derived resistance index in the ophthalmic artery: flow velocities in this vessel were identical at IOP of 8 mm Hg or 45 mm Hg. In contrast, in the central retinal artery, PSV and EDV fell, and the resistance index rose, in steady progression as IOP was acutely elevated (each p < 0.01). At IOP of 45 mm Hg, EDV was virtually absent and the resistance index was very nearly 1.0. CONCLUSION: Ophthalmic arterial haemodynamics are unrelated to acute fluctuations of the IOP over a wide range, suggesting that ocular hypertension itself cannot induce vascular dysfunction in this artery. In contrast, flow velocities in the central retinal artery were highly IOP dependent, implying that haemodynamic and mechanical factors are closely linked in this vascular bed. PMID:9059269

  14. Assessment of capillary suction time (CST) test methodologies.

    PubMed

    Sawalha, O; Scholz, M

    2007-12-01

    The capillary suction time (CST) test is a commonly used method to measure the filterability and the easiness of removing moisture from slurry and sludge in numerous environmental and industrial applications. This study assessed several novel alterations of both the test methodology and the current standard capillary suction time (CST) apparatus. Twelve different papers including the standard Whatman No. 17 chromatographic paper were tested. The tests were run using four different types of sludge including a synthetic sludge, which was specifically developed for benchmarking purposes. The standard apparatus was altered by the introduction of a novel rectangular funnel instead of a standard circular one. A stirrer was also introduced to solve the problem of test inconsistency (e.g. high CST variability) particularly for heavy types of sludge. Results showed that several alternative papers, which are cheaper than the standard paper, can be used to estimate CST values accurately, and that the test repeatability can be improved in many cases and for different types of sludge. The introduction of the rectangular funnel demonstrated an obvious enhancement of test repeatability. The use of a stirrer to avoid sedimentation of heavy sludge did not have statistically significant impact on the CST values or the corresponding data variability. The application of synthetic sludge can support the testing of experimental methodologies and should be used for subsequent benchmarking purposes. PMID:18341148

  15. Suction based mechanical characterization of superficial facial soft tissues.

    PubMed

    Weickenmeier, J; Jabareen, M; Mazza, E

    2015-12-16

    The present study is aimed at a combined experimental and numerical investigation of the mechanical response of superficial facial tissues. Suction based experiments provide the location, time, and history dependent behavior of skin and SMAS (superficial musculoaponeurotic system) by means of Cutometer and Aspiration measurements. The suction method is particularly suitable for in vivo, multi-axial testing of soft biological tissue including a high repeatability in subsequent tests. The campaign comprises three measurement sites in the face, i.e. jaw, parotid, and forehead, using two different loading profiles (instantaneous loading and a linearly increasing and decreasing loading curve), multiple loading magnitudes, and cyclic loading cases to quantify history dependent behavior. In an inverse finite element analysis based on anatomically detailed models an optimized set of material parameters for the implementation of an elastic-viscoplastic material model was determined, yielding an initial shear modulus of 2.32kPa for skin and 0.05kPa for SMAS, respectively. Apex displacements at maximum instantaneous and linear loading showed significant location specificity with variations of up to 18% with respect to the facial average response while observing variations in repeated measurements in the same location of less than 12%. In summary, the proposed parameter sets for skin and SMAS are shown to provide remarkable agreement between the experimentally observed and numerically predicted tissue response under all loading conditions considered in the present study, including cyclic tests. PMID:26584965

  16. An Ultrasonic Suction Pump with No Physically Moving Parts

    NASA Astrophysics Data System (ADS)

    Yun, Cheol-Ho; Hasegawa, Takeshi; Nakamura, Kentaro; Ueha, Sadayuki

    2004-05-01

    A new ultrasonic suction pump is described in this paper. The pump uses the suction force of a rigid cylinder tube vibrating at an ultrasonic frequency and has no physically moving parts. The pump consists of a longitudinal bolt-clamped Langevin transducer (BLT) combined with a stepped horn working at a resonance frequency of 24 kHz. A glass tube with the length of the half-wavelength-resonance is glued at the tip of the horn. To enhance pump performance, we introduced a reflection plate and a thin rod installed to the end of the glass tube with a small gap. Maximum pressures of 7.2 kPa and 23.5 kPa were recorded using the reflection plate and the thin rod, respectively. In this study, we experimentally investigate the characteristics of the pump and the operating physics. The maximum pressure is a function of the vibration velocity of the end surface of the glass tube and of the gap.

  17. Behavior of Water Jet Accompanied with Air Suction

    NASA Astrophysics Data System (ADS)

    Kawakami, Hironobu; Ishido, Tsutomu; Ihara, Akio

    In order to atomize a liquid, the authors have investigated the behavior of air-water jets. In a series of experiments, we have discovered a strange phenomenon that the water jet accompanied with air suction from the free surface has made a periodic radial splash of water drop. The purpose of the present paper is to clear out the origin of this phenomenon and the behavior of water jet accompanied with air suction. The behavior of water jet has been photographed by a digital camera aided with a flashlight and high-speed video camera. Those experiments enable us to find the origin of a periodic radial splash due to a formation of single air bubble at the flow separation region inside the nozzle and due to explosive expansion of the bubble after injected in the free space. In order to analyze the radial splash of water, we have conducted the equation of spherical liquid membrane. The numerical results obtained have been compared with the experimental results and good agreement has been obtained in radial expansion velocity.

  18. Cavitation improvement of double suction centrifugal pump HPP Fuhren

    NASA Astrophysics Data System (ADS)

    Škerlavaj, A.; Titzschkau, M.; Pavlin, R.; Vehar, F.; Mežnar, P.; Lipej, A.

    2012-11-01

    A double suction storage pump has been refurbished because of the strong cavitation which resulted in cavitation damage on blade and consequently in frequent repairs of the impeller. The analyses of the old and the new impeller were done by the computational fluid dynamics (CFD), performing transient simulations with the commercial solver Ansys CFX. In the simulations, the scale-adaptive-simulation with the curvature correction (SAS-CC) turbulence model was used. No model tests were carried out. Additionally, observations with the digital camera were made through the specially designed plexi-glass window, mounted at the lid at the suction side. The predicted pump head at the operating point agrees well with the pump characteristics measurements, performed with the direct thermodynamic method. The extent of the cavitation predicted by CFD is smaller than the observed one because the cloud cavitation was not predicted. The observations of the cavitation extent show that the impeller design is better than the old one, which was also possible to anticipate based on the CFD results.

  19. Assessment of capillary suction time (CST) test methodologies.

    PubMed

    Sawalha, O; Scholz, M

    2007-12-01

    The capillary suction time (CST) test is a commonly used method to measure the filterability and the easiness of removing moisture from slurry and sludge in numerous environmental and industrial applications. This study assessed several novel alterations of both the test methodology and the current standard capillary suction time (CST) apparatus. Twelve different papers including the standard Whatman No. 17 chromatographic paper were tested. The tests were run using four different types of sludge including a synthetic sludge, which was specifically developed for benchmarking purposes. The standard apparatus was altered by the introduction of a novel rectangular funnel instead of a standard circular one. A stirrer was also introduced to solve the problem of test inconsistency (e.g. high CST variability) particularly for heavy types of sludge. Results showed that several alternative papers, which are cheaper than the standard paper, can be used to estimate CST values accurately, and that the test repeatability can be improved in many cases and for different types of sludge. The introduction of the rectangular funnel demonstrated an obvious enhancement of test repeatability. The use of a stirrer to avoid sedimentation of heavy sludge did not have statistically significant impact on the CST values or the corresponding data variability. The application of synthetic sludge can support the testing of experimental methodologies and should be used for subsequent benchmarking purposes.

  20. [Swimming pool suction injury: etiology, profylaxis and management].

    PubMed

    Škach, J; Kašák, P; Šrám, J

    2015-01-01

    Swimming pool suction injuries are unique and rare with a substantive risk of fatal consequences. Little children under the age of 8 are the most frequent victims with serious injuries. Drownings of different seriousness are also a usual part of accidents. The case of a 19 year old man trapped in the gluteal area by a unsecured suction drainage hole illustrates the uniqueness of this problem in an interesting way. Prophylactic arrangements are well known but the problem is with their strict application. Fatal causes excluding drowning include hypovolemic shock from the sudden redistribution of intersticial fluid and blood and also the evisceration of the bowel and other abdominal organs. Localised often bizarre and large swellings and sufusions can be treated nonoperatively in the vast majority of cases. For the prevention of these injuries it is important to inform the public and increase their awareness to these injuries. It is also crucial for the correct management of these injuries a deeper awareness of this issue and a sharing of experiences and solutions with other experts.Key words: vacuum - accident - entrapment - compartment syndrome.

  1. Adaptive Suction and Blowing for Twin-Tail Buffet Control

    NASA Technical Reports Server (NTRS)

    Kandil, Osama A.; Yang, Zhi

    1999-01-01

    Adaptive active flow control for twin-tail buffet alleviation is investigated. The concept behind this technique is to place control ports on the tail outer and inner surfaces with flow suction or blowing applied through these ports in order to minimize the pressure difference across the tail. The suction or blowing volume flow rate from each port is proportional to the pressure difference across the tail at this location. A parametric study of the effects of the number and location of these ports on the buffet response is carried out. The computational model consists of a sharp-edged delta wing of aspect ratio one and swept-back flexible twin tail with taper ratio of 0.23. This complex multidisciplinary problem is solved sequentially using three sets of equations for the fluid flow, aeroelastic response and grid deformation, using a dynamic multi-block grid structure. The computational model is pitched at 30 deg angle of attack. The freestream Mach number and Reynolds number are 0.3 and 1.25 million, respectively. The model is investigated for the inboard position of the twin tails, which corresponds to a separation distance between the twin tails of 33% of the wing span. Comparison of the time history and power spectral density responses of the tails for various distributions of the control ports are presented and discussed.

  2. Temperature Measurement in WTE Boilers Using Suction Pyrometers

    PubMed Central

    Rinaldi, Fabio; Najafi, Behzad

    2013-01-01

    The temperature of the flue-gas in the post combustion zone of a waste to energy (WTE) plant has to be maintained within a fairly narrow range of values, the minimum of which is prescribed by the European Waste Directive 2000/76/CE, whereas the maximum value must be such as to ensure the preservation of the materials and the energy efficiency of the plant. A high degree of accuracy in measuring and controlling the aforementioned temperature is therefore required. In almost the totality of WTE plants this measurement process is carried out by using practical industrial thermometers, such as bare thermocouples and infrared radiation (IR) pyrometers, even if affected by different physical contributions which can make the gas temperature measurements incorrect. The objective of this paper is to analyze errors and uncertainties that can arise when using a bare thermocouple or an IR pyrometer in a WTE plant and to provide a method for the in situ calibration of these industrial sensors through the use of suction pyrometers. The paper describes principle of operation, design, and uncertainty contributions of suction pyrometers, it also provides the best estimation of the flue-gas temperature in the post combustion zone of a WTE plant and the estimation of its expanded uncertainty. PMID:24248279

  3. Temperature measurement in WTE boilers using suction pyrometers.

    PubMed

    Rinaldi, Fabio; Najafi, Behzad

    2013-01-01

    The temperature of the flue-gas in the post combustion zone of a waste to energy (WTE) plant has to be maintained within a fairly narrow range of values, the minimum of which is prescribed by the European Waste Directive 2000/76/CE, whereas the maximum value must be such as to ensure the preservation of the materials and the energy efficiency of the plant. A high degree of accuracy in measuring and controlling the aforementioned temperature is therefore required. In almost the totality of WTE plants this measurement process is carried out by using practical industrial thermometers, such as bare thermocouples and infrared radiation (IR) pyrometers, even if affected by different physical contributions which can make the gas temperature measurements incorrect. The objective of this paper is to analyze errors and uncertainties that can arise when using a bare thermocouple or an IR pyrometer in a WTE plant and to provide a method for the in situ calibration of these industrial sensors through the use of suction pyrometers. The paper describes principle of operation, design, and uncertainty contributions of suction pyrometers, it also provides the best estimation of the flue-gas temperature in the post combustion zone of a WTE plant and the estimation of its expanded uncertainty. PMID:24248279

  4. Fish oil supplementation suppresses resistance exercise and feeding-induced increases in anabolic signaling without affecting myofibrillar protein synthesis in young men.

    PubMed

    McGlory, Chris; Wardle, Sophie L; Macnaughton, Lindsay S; Witard, Oliver C; Scott, Fraser; Dick, James; Bell, J Gordon; Phillips, Stuart M; Galloway, Stuart D R; Hamilton, D Lee; Tipton, Kevin D

    2016-03-01

    Fish oil (FO) supplementation potentiates muscle protein synthesis (MPS) in response to a hyperaminoacidemic-hyperinsulinemic infusion. Whether FO supplementation potentiates MPS in response to protein ingestion or when protein ingestion is combined with resistance exercise (RE) remains unknown. In a randomized, parallel group design, 20 healthy males were randomized to receive 5 g/day of either FO or coconut oil control (CO) for 8 weeks. After supplementation, participants performed a bout of unilateral RE followed by ingestion of 30 g of whey protein. Skeletal muscle biopsies were obtained before and after supplementation for assessment of muscle lipid composition and relevant protein kinase activities. Infusion of L-[ring-(13)C6] phenylalanine was used to measure basal myofibrillar MP Sat rest (REST), in a nonexercised leg following protein ingestion (FED) and following RE and protein ingestion (FEDEX).MPS was significantly elevated above REST during FEDEX in both the FO and CO groups, but there was no effect of supplementation. There was a significant increase in MPS in both groups above REST during FED but no effect of supplementation. Supplementation significantly decreased pan PKB activity at RESTin the FO group but not the CO group. There was a significant increase from REST at post-RE for PKB and AMPKα2 activity in the CO group but not in the FO group. In FEDEX, there was a significant increase in p70S6K1 activity from REST at 3 h in the CO group only. These data highlight that 8 weeks of FO supplementation alters kinase signaling activity in response to RE plus protein ingestion without influencing MPS. PMID:27009278

  5. Fish oil supplementation suppresses resistance exercise and feeding-induced increases in anabolic signaling without affecting myofibrillar protein synthesis in young men.

    PubMed

    McGlory, Chris; Wardle, Sophie L; Macnaughton, Lindsay S; Witard, Oliver C; Scott, Fraser; Dick, James; Bell, J Gordon; Phillips, Stuart M; Galloway, Stuart D R; Hamilton, D Lee; Tipton, Kevin D

    2016-03-01

    Fish oil (FO) supplementation potentiates muscle protein synthesis (MPS) in response to a hyperaminoacidemic-hyperinsulinemic infusion. Whether FO supplementation potentiates MPS in response to protein ingestion or when protein ingestion is combined with resistance exercise (RE) remains unknown. In a randomized, parallel group design, 20 healthy males were randomized to receive 5 g/day of either FO or coconut oil control (CO) for 8 weeks. After supplementation, participants performed a bout of unilateral RE followed by ingestion of 30 g of whey protein. Skeletal muscle biopsies were obtained before and after supplementation for assessment of muscle lipid composition and relevant protein kinase activities. Infusion of L-[ring-(13)C6] phenylalanine was used to measure basal myofibrillar MP Sat rest (REST), in a nonexercised leg following protein ingestion (FED) and following RE and protein ingestion (FEDEX).MPS was significantly elevated above REST during FEDEX in both the FO and CO groups, but there was no effect of supplementation. There was a significant increase in MPS in both groups above REST during FED but no effect of supplementation. Supplementation significantly decreased pan PKB activity at RESTin the FO group but not the CO group. There was a significant increase from REST at post-RE for PKB and AMPKα2 activity in the CO group but not in the FO group. In FEDEX, there was a significant increase in p70S6K1 activity from REST at 3 h in the CO group only. These data highlight that 8 weeks of FO supplementation alters kinase signaling activity in response to RE plus protein ingestion without influencing MPS.

  6. Fish Allergy

    MedlinePlus

    ... Story" 5 Things to Know About Zika & Pregnancy Fish Allergy KidsHealth > For Parents > Fish Allergy Print A ... From Home en español Alergia al pescado About Fish Allergy A fish allergy is not exactly the ...

  7. Gray whale and walrus feeding excavation on the Bering Shelf, Alaska.

    USGS Publications Warehouse

    Nelson, C.H.; Johnson, K.R.; Barber, J.H.

    1987-01-01

    The gray whales (average mouth length, 2.0 m), when suction feeding on infaunal amphipods, create shallow pits in the sea floor, typically 2.5m x 1.5m x 10cm deep, which are distinct and mappable on sidescan sonographs. Similarly, walrus, when foraging for shallow clams, create long, linear feeding furrows that average 47 x 0.4 x 0.1m (length-width-depth). The whale feeding pits are commonly enlarged and oriented by seasonal storm-related scour. Walrus-feeding features are smaller, formed in higher-energy environments, and modified more rapidly than whale-feeding pits. -from Authors

  8. One Fish Two Fish.

    ERIC Educational Resources Information Center

    Hoffman, Michele

    1998-01-01

    This activity explains fisheries resource management to seven-year olds. First-grade students learn concepts such as offspring viability, life expectancy, and distribution of species, which help to determine when, where, and how people fish and the importance of fishing responsibly. Lists materials, procedures, and extensions. (SJR)

  9. 75 FR 70112 - Medical Devices; General and Plastic Surgery Devices; Classification of Non-Powered Suction...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-17

    ... Devices; Classification of Non-Powered Suction Apparatus Device Intended for Negative Pressure Wound... Administration (FDA) is classifying the non- powered suction apparatus device intended for negative pressure... Apparatus Device Intended for Negative Pressure Wound Therapy.'' The agency is classifying the device...

  10. Tono-Pen XL tonometry during application of a suction ring in rabbits

    PubMed Central

    Charisis, Spyridon K; Ginis, Harilaos S; Kounis, Georgios A; Tsilimbaris, Miltiadis K

    2008-01-01

    Background The purpose of this study is to evaluate the use of Tono-Pen XL in measuring IOP during the application of a suction ring in rabbit eyes with manometrically controlled IOP. Methods Tono-Pen XL was calibrated against direct manometry in 10 rabbit eyes. A suction ring was then applied in 4 rabbit eyes and the IOP was determined manometrically during suction ring application at 350 mmHg vacuum pressure. Finally, in 6 catheterized rabbit eyes the IOP was measured with Tono-Pen XL during suction ring application at suction vacuum from 350 to 650 mmHg, while keeping actual IOP stable at 30 mmHg and 60 mmHg. Results Linear regression analysis revealed that the Tono-pen XL was reliable for IOPs between 10 and 70 mmHg (R2 = 0.9855). Direct manometry during suction ring application showed no statistically significant variation of Tono-Pen XL readings when the incanulation manometry intraocular pressure changed from 30 mmHg to 60 mmHg and no statistically significant correlation between suction vacuum and IOP measurements. Conclusion Tono-Pen XL measurements are unreliable during the application of a suction ring on living rabbit eyes even when the actual IOP is forced to be within the validated range of Tono-Pen XL measurements. This inaccuracy is probably related to altered corneal and scleral geometry and stress. PMID:18667058

  11. DETAIL OF DENVER DISC FILTER IN CO91107, SUCTION END. NOTE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL OF DENVER DISC FILTER IN CO-91-107, SUCTION END. NOTE BEARING HOUSING WITH CAST LOGO, SUCTION PIPE GOING OFF TO THE RIGHT, AND FILTER DISC IN BACKGROUND. VACUUM INSIDE DISCS FURTHER DEWATERED CONCENTRATE. AS DISC SLOWLY ROTATED A BAR SCRAPED DRIED CONCENTRATE FROM OUTSIDE OF FILTER CLOTH. - Shenandoah-Dives Mill, 135 County Road 2, Silverton, San Juan County, CO

  12. 21 CFR 878.4680 - Nonpowered, single patient, portable suction apparatus.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... apparatus. 878.4680 Section 878.4680 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND....4680 Nonpowered, single patient, portable suction apparatus. (a) Identification. A nonpowered, single patient, portable suction apparatus is a device that consists of a manually operated plastic,...

  13. 21 CFR 878.4680 - Nonpowered, single patient, portable suction apparatus.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... apparatus. 878.4680 Section 878.4680 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND....4680 Nonpowered, single patient, portable suction apparatus. (a) Identification. A nonpowered, single patient, portable suction apparatus is a device that consists of a manually operated plastic,...

  14. 46 CFR 134.180 - Piping for fire-main suction.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Piping for fire-main suction. 134.180 Section 134.180 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS ADDED PROVISIONS FOR LIFTBOATS § 134.180 Piping for fire-main suction. (a) Except as provided by paragraph (b) of...

  15. 46 CFR 134.180 - Piping for fire-main suction.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Piping for fire-main suction. 134.180 Section 134.180 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS ADDED PROVISIONS FOR LIFTBOATS § 134.180 Piping for fire-main suction. (a) Except as provided by paragraph (b) of...

  16. 21 CFR 870.4270 - Cardiopulmonary bypass cardiotomy suction line blood filter.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... blood filter. 870.4270 Section 870.4270 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Devices § 870.4270 Cardiopulmonary bypass cardiotomy suction line blood filter. (a) Identification. A cardiopulmonary bypass cardiotomy suction line blood filter is a device used as part of a gas exchange...

  17. An Analysis of Reciprocating Compressor Suction System Using Digital Image Processing

    NASA Astrophysics Data System (ADS)

    Lee, In-Seop; Kaga, Akikazu; Yamaguchi, Katsuhito

    In a reciprocating compressor having close distance between a suction pipe and a suction muffler, great part of refrigerant flowing from the suction pipe is directly sucked into the suction muffler. But a part of refrigerant leaks into the void space in the hermetic shell and contacts with the cylinder, the motor or other high temperature parts. The temperature rise of refrigerant due to this leakage decreases the efficiency of a compressor. Therefore the efficiency of the compressor increases with decrease the amount of leakage. In this paper, the direct suction ratio (DSR) is defined as the ratio of the flow rate of refrigerant directly sucked to the total flow rate from the suction pipe, and measured with a new technique using digital image processing. The technique developed measures the temporal decrease of visible tracer particles filled initially within the hermetic shell of a compressor visualization model, and calculates the DSR from the rate of concentration decrease. The technique is applied to improve the performance of reciprocating compressor by modifying the shape of the suction pipe which gives higher DSR. Although refrigerant flow velocity around suction pipe and muffler is required as a fundamental data for further improvement of the performance, there has been no report or paper which measures these data due to the difficulty in insertion of velocity sensor into hermetic shell. In this paper, flow velocity data obtained with a PIV (Particle Imaging Velocimetry) technique applied to compressor visualization model is also presented.

  18. Impact of supra-cuff suction on ventilator-associated pneumonia prevention

    PubMed Central

    de Souza, Carolina Ramos; Santana, Vivian Taciana Simioni

    2012-01-01

    Critically ill patients are intubated or tracheostomized because, in most cases, these individuals require invasive mechanical ventilation. The cannulae that are used include the cuff, which can act as a reservoir for oropharyngeal secretions, predisposing to ventilator-associated pneumonia. Studies have revealed that the suction of subglottic secretions through the dorsal suction lumen above the endotracheal tube cuff delays the onset and reduces the incidence of ventilator-associated pneumonia. The aim of this review is to assess published studies regarding the significance of using suction with a supra-cuff device for the prevention of ventilator-associated pneumonia in critically ill patients treated with orotracheal intubation or tracheostomy. Therefore, by searching national and international databases, a literature review was undertaken of studies published between the years 1986 and 2011. Few results were found relating the suction of subglottic secretions to decreased duration of mechanical ventilation and length of stay in the intensive care unit. The suction of subglottic secretions is ineffective in decreasing mortality but is effective in reducing the incidence of early-onset ventilator-associated pneumonia and hospital costs. Techniques involving continuous suction of subglottic secretions may be particularly efficient in removing secretions; however, intermittent suction appears to be the least harmful method. In conclusion, cannulae with a supra-cuff suction device enable the aspiration of subglottic secretions, providing benefits to critically ill patients by reducing the incidence of ventilator-associated pneumonia and, consequently, hospital costs - with no large-scale adverse effects. PMID:23917940

  19. Cardiopulmonary and intracranial pressure changes related to endotracheal suctioning in preterm infants.

    PubMed

    Durand, M; Sangha, B; Cabal, L A; Hoppenbrouwers, T; Hodgman, J E

    1989-06-01

    Although endotracheal (ET) suctioning is performed frequently in sick newborn infants, its effects on cardiorespiratory variables and intracranial pressure (ICP) have not been thoroughly documented in neonates greater than 24 h who were not paralyzed while receiving mechanical ventilation. This study evaluates these changes in preterm infants who required ventilatory assistance. We measured transcutaneous PO2 and PCO2 (PtcO2 and PtcCO2, respectively), intra-arterial BP, heart rate, ICP, and cerebral perfusion pressure (CPP) before, during, and for at least 5 min after ET suctioning in 15 low birth weight infants less than 1500 g and less than or equal to 30 days of age. One infant was studied twice. A suction adaptor was used to avoid disconnecting the patient from the ventilator and to attempt to minimize hypoxemia and hypercapnia during suctioning. The patients were studied in the supine position and muscle relaxants were not used. PtcO2 decreased 12.1% while PtcCO2 increased 4.7% 1 min after suctioning; however, greater increases in mean BP (33%) and ICP (117%) were observed during suctioning. CPP also increased during the procedure. ICP returned to baseline almost immediately, whereas BP remained slightly elevated 1 min after suctioning. Our findings demonstrate that ET suctioning significantly increases BP, ICP, and CPP in preterm infants on assisted ventilation in the first month of life. These changes appear to be independent of changes observed in oxygenation and ventilation.

  20. History and development of suction-irrigation-reaming.

    PubMed

    Green, James

    2010-11-01

    Excessive intramedullary pressure coincident to surgical procedures requiring entrance and surgical manipulation within the intramedullary canal is a problem that was recognized by Gerhard Küntscher, the godfather of intramedullary nailing. He expressed concern about this phenomenon in his early writings during the 1940's. Although he suggested certain technical methods to moderate the event while doing the surgical procedure he had no solution for absolutely preventing its occurrence. This became more of an issue after he introduced motorized reaming in the mid 1950's to improve the strength of intramedullary fixation. The first to demonstrate that pressure could be avoided during intramedullary surgeries were Lorenzi, Olerud and Dankwardt-Lillieström in the late 1960's. Using a method that employed suction evacuation of intramedullary content prior to reaming, and by introducing irrigation while reaming, they were able to achieve negative pressures during their intramedullary work. They proved that if an IM technique did not inject fat throughout the bone and into the organism there were significant benefits both locally and systemically. With impeccable methodology, they showed fat destroyed the vascularity of the bone and inhibited its revascularization. Systemically, its presence was associated with death and morbidity. K.M. Stürmer, using sheep in studies done in the 1980's, further validated the effectiveness of negative pressure reaming to prevent adverse effects associated with reaming. The attempt to create a device to provide these benefits clinically, however, has been challenging. The group in Muenster did work with a rinsing-suction-reamer (RSR) that showed fat introduction with reaming need not be significantly greater than when using an external fixator. In the US, the effort has focused on developing a reamer that integrated suction and irrigation into its design. This instrument has been given the acronym of RIA (reamer

  1. [Enteral tube feeding].

    PubMed

    Haller, Alois

    2014-03-01

    Tube feeding is an integral part of medical therapies, and can be easily managed also in the outpatient setting. Tube feeding by the stomach or small intestine with nasogastral or nasojejunal tubes is common in clinical practice. Long-term nutrition is usually provided through a permanent tube, i. e. a percutaneous endoscopic gastrostomy (PEG). Modern portable nutrition pumps are used to cover the patient's nutritional needs. Enteral nutrition is always indicated if patients can not or should not eat or if nutritional requirements cannot be covered within 3 days after an intervention, e. g. after abdominal surgery. Industrially produced tube feedings with defined substrate concentrations are being used; different compositions of nutrients, such as glutamine fish oil etc., are used dependent on the the condition of the patient. Enteral nutrition may be associated with complications of the tube, e. g. dislocation, malposition or obstruction, as well as the feeding itself, e. g.hyperglycaemia, electrolyte disturbances, refeeding syndrome diarrhea or aspiration). However, the benefit of tube feeding usually exceeds the potential harm substantially.

  2. Experiments on the stability of the flat-plate boundary layer with suction

    NASA Technical Reports Server (NTRS)

    Reynolds, G. A.; Saric, W. S.

    1982-01-01

    Experiments have been conducted in the VPI and SU Stability Wind Tunnel on a flat-plate wind-tunnel model equipped with porous suction panels. Detailed hot-wire measurements were conducted in the laminar boundary layer to investigate the stabilizing effects of suction on growing Tollmien-Schlichting waves, which were introduced into the boundary layer using a vibrating ribbon. Special care was taken to minimize external disturbances and to avoid extraneous experimental bias. The measurements, which included mean-flow and disturbance-amplitude profiles across the boundary layer, showed that suction applied through discrete porous strips can be as effective as suction applied continuously over a much longer streamwise length. The measurements also showed that suction is more effective when placed forward, nearer to the region of neutral stability, than when placed in the region of maximum growth rate. These results also provided meaningful comparison with recent theory.

  3. The suction pouch for management of simple or complex enterocutaneous fistulae.

    PubMed

    Franklin, Christoph

    2010-01-01

    Containing effluent from an enterocutaneous fistula (ECF) requires expertise, critical thinking skills, and creativity. Using a combination of products readily available to WOC nurses practicing in the United States, I have designed a suction pouch that reliably contains fistula output. A standard ostomy pouch can be converted into a suction pouch by adding a large, single-lumen catheter into the pouch, sealing it, and connecting the assembly to low continuous suction. The resulting pouch can be used by itself to drain effluent from an ECF or it can be used in combination with wound dressings, or a negative pressure wound therapy system. Application of a suction pouch extends the integrity of the appliance and diverts succus away from the wound bed or the newly applied skin graft with increased reliability. This article describes the technique used to create a suction pouch, followed by 4 brief case descriptions that demonstrate feasibility of its use for the management of ECFs.

  4. Trematode infections in farm-raised fish: Reasons for massive infections, impacts on fish and fish farms, and management of infections on fish farms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There is an increasing problem with trematodes in fish production facilities. The onset and growth of pond aquaculture in the US (1950-1990) resulted in concentrated areas of fish, new sites for snail growth and multiplication, and new bird feeding habitat. Snails, fish, and birds serve as hosts for...

  5. Case study involving suctioning of an electromyographic endotracheal tube.

    PubMed

    Evanina, Eileen Youshock; Hanisak, Jill L

    2005-04-01

    The electromyographic endotracheal tube (EMG-ETT) is a relatively new tool used to measure integrity of the vocal cord structures during surgery. We describe a case in which an EMG-ETT was inserted for the operative period but not replaced with an ETT during the immediate postoperative period. Intensive care unit nurses had difficulty suctioning the EMG-ETT. The patient was not provided the pulmonary toilet necessary until the EMG-ETT was removed and replaced with a regular ETT. The purpose of this article is to make anesthesia providers aware that when mechanical ventilation is required during the postoperative period, the EMG-ETT should be removed and replaced with a regular ETT to facilitate pulmonary toilet. PMID:15835830

  6. Flat slab deformation caused by interplate suction force

    NASA Astrophysics Data System (ADS)

    Ma, Yiran; Clayton, Robert W.

    2015-09-01

    We image the structure at the southern end of the Peruvian flat subduction zone, using receiver function and surface wave methods. The Nazca slab subducts to ~100 km depth and then remains flat for ~300 km distance before it resumes the dipping subduction. The flat slab closely follows the topography of the continental Moho above, indicating a strong suction force between the slab and the overriding plate. A high-velocity mantle wedge exists above the initial half of the flat slab, and the velocity resumes to normal values before the slab steepens again, indicating the resumption of dehydration and ecologitization. Two prominent midcrust structures are revealed in the 70 km thick crust under the Central Andes: molten rocks beneath the Western Cordillera and the underthrusting Brazilian Shield beneath the Eastern Cordillera.

  7. Effects of shallow and deep endotracheal tube suctioning on cardiovascular indices in patients in intensive care units

    PubMed Central

    Irajpour, Alireza; Abbasinia, Mohammad; Hoseini, Abbas; Kashefi, Parviz

    2014-01-01

    Background: Clearing the endotracheal tube through suctioning should be done to promote oxygenation. Depth of suctioning is one of the variables in this regard. In shallow suctioning method, the catheter passes to the tip of the endotracheal tube, and in deep suctioning method, it passes beyond the tip into the trachea or brunches. This study aimed to evaluate the effect of shallow and deep suctioning methods on cardiovascular indices in patients hospitalized in the intensive care units (ICUs). Materials and Methods: In this clinical trial, 74 patients were selected among those who had undergone mechanical ventilation in the ICU of Al-Zahra Hospital, Isfahan, Iran using convenience sampling method. The subjects were randomly allocated to shallow and deep suctioning groups. Heart rate (HR) and blood pressure (BP) were measured immediately before and 1, 2, and 3 min after each suctioning. Number of times of suctioning was also noted in both the groups. Data were analyzed using repeated measures analysis of variance (ANOVA), Chi-square and independent t-tests. Results: HR and BP were significantly increased after suctioning in both the groups (P < 0.05). But these changes were not significant between the two groups (P > 0.05). The suctioning count was significantly higher in the shallow suctioning group than in the deep suctioning group. Conclusions: Shallow and deep suctioning were similar in their effects on HR and BP, but shallow suctioning caused further manipulation of patient's trachea than deep suctioning method. Therefore, in order to prevent complications, nurses are recommended to perform the endotracheal tube suctioning by the deep method. PMID:25183976

  8. Uniform flow over a permeable plane with downward suction

    NASA Astrophysics Data System (ADS)

    Hsieh, Ping-Cheng; Lin, Yen-Ti

    2015-04-01

    In previous research, studies on channel flow were mostly focused on the flow profiles with consideration of the horizontal (or streamwise) velocity component only. Due to the neglect of the vertical velocity component, the governing equations were simplified and then the analytical solutions could be probably derived. However, the vertical velocity as well as the horizontal velocity is actually existent in the real world, especially at the water-porous matrix interface. This study derives an analytical solution to a two-dimensional flow field composed of a uniform flow over a plane homogeneous porous medium with downward suction. The Navier-Stokes equations are employed to describe the water flow, whereas the poroelastic theory is addressed for the pore water flow. Setting the stream function for the velocity components associated with corresponding boundary conditions, we successfully find the solutions to the dimensionless boundary-value problem by taking the six-order power series method (PSM) and differential transform method (DTM), respectively. After the stream function is solved, the vertical velocity component as well as the horizontal velocity component can be obtained. The present results agree very well with the previous study which was carried out by a numerical method. This validates the presented analytical solutions separately by PSM and DTM. The vertical velocity increases gradually from the top lid to the bottom of the porous medium. The maximum horizontal velocity component is about 1.64 times of the downward suction velocity and occurs at a little below the centerline of the total depth. It is noted that the vertical velocity component should not be neglected in a two-dimensional flow, and the horizontal velocity might be affected by the vertical one. The present study also shows that the flow field of a two-dimensional flow is possible to be solved by analytical approaches. The employed technique and methods will be applied to the future study

  9. The better to eat you with: the comparative feeding morphology of phocid seals (Pinnipedia, Phocidae).

    PubMed

    Kienle, Sarah S; Berta, Annalisa

    2016-03-01

    One adaptation crucial to the survival of mammalian lineages that secondarily transitioned from land to water environments was the ability to capture and consume prey underwater. Phocid seals have evolved diverse feeding strategies to feed in the marine environment, and the objectives of this study were to document the specialized feeding morphologies and identify feeding strategies used by extant phocids. This study used principal component analysis (PCA) to determine the major axes of diversification in the skull for all extant phocid taxa and the recently extinct Caribbean monk seal (n = 19). Prey data gathered from the literature and musculoskeletal data from dissections were included to provide a comprehensive description of each feeding strategy. Random Forest analysis was used to determine the morphological, ecological and phylogenetic variables that best described each feeding strategy. There is morphological evidence for four feeding strategies in phocids: filter; grip and tear; suction; and pierce feeding. These feeding strategies are supported by quantitative cranial and mandibular characters, dietary information, musculoskeletal data and, for some species, behavioral observations. Most phocid species are pierce feeders, using a combination of biting and suction to opportunistically catch prey. Grip and tear and filter feeding are specialized strategies with specific morphological adaptations. These unique adaptations have allowed leopard seals (Hydrurga leptonyx) and crabeater seals (Lobodon carcinophaga) to exploit novel ecological niches and prey types. This study provides the first cranial and mandibular morphological evidence for the use of specialized suction feeding in hooded seals (Cystophora cristata), northern elephant seals (Mirounga angustirostris) and southern elephant seals (Mirounga leonina). The most important variables in determining the feeding strategy of a given phocid species were cranial and mandibular shape, diet, and phylogeny

  10. The better to eat you with: the comparative feeding morphology of phocid seals (Pinnipedia, Phocidae).

    PubMed

    Kienle, Sarah S; Berta, Annalisa

    2016-03-01

    One adaptation crucial to the survival of mammalian lineages that secondarily transitioned from land to water environments was the ability to capture and consume prey underwater. Phocid seals have evolved diverse feeding strategies to feed in the marine environment, and the objectives of this study were to document the specialized feeding morphologies and identify feeding strategies used by extant phocids. This study used principal component analysis (PCA) to determine the major axes of diversification in the skull for all extant phocid taxa and the recently extinct Caribbean monk seal (n = 19). Prey data gathered from the literature and musculoskeletal data from dissections were included to provide a comprehensive description of each feeding strategy. Random Forest analysis was used to determine the morphological, ecological and phylogenetic variables that best described each feeding strategy. There is morphological evidence for four feeding strategies in phocids: filter; grip and tear; suction; and pierce feeding. These feeding strategies are supported by quantitative cranial and mandibular characters, dietary information, musculoskeletal data and, for some species, behavioral observations. Most phocid species are pierce feeders, using a combination of biting and suction to opportunistically catch prey. Grip and tear and filter feeding are specialized strategies with specific morphological adaptations. These unique adaptations have allowed leopard seals (Hydrurga leptonyx) and crabeater seals (Lobodon carcinophaga) to exploit novel ecological niches and prey types. This study provides the first cranial and mandibular morphological evidence for the use of specialized suction feeding in hooded seals (Cystophora cristata), northern elephant seals (Mirounga angustirostris) and southern elephant seals (Mirounga leonina). The most important variables in determining the feeding strategy of a given phocid species were cranial and mandibular shape, diet, and phylogeny

  11. 21 CFR 878.4683 - Non-Powered suction apparatus device intended for negative pressure wound therapy.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Non-Powered suction apparatus device intended for... Surgical Devices § 878.4683 Non-Powered suction apparatus device intended for negative pressure wound therapy. (a) Identification. A non-powered suction apparatus device intended for negative pressure...

  12. [Development of oral feeding skills in the preterm infant].

    PubMed

    Lau, C

    2007-09-01

    Preterm infants cannot readily transition from tube to oral feeding. Such difficulty often delays their discharge from the hospital and mother-infant reunion. Therefore, understanding the development of the necessary skills preterm infants need to acquire for safe and successful oral feeding is essential. It is now recognized that a mature sucking pattern consisting of the rhythmic alternation of suction and expression is not sufficient for an infant to feed by mouth safely. Rather, an adequate coordination of sucking, swallowing, and respiration appear to be crucial if the infant is to feed with no episodes of desaturation, apnea, bradycardia, and/or aspiration. Studies have shown the benefits of some interventions in facilitating oral feeding in the preterm infant. However, it remains to be determined whether these effects can be generalized.

  13. Managing urine leakage following laparoscopic radical prostatectomy with active suction of the prevesical space

    PubMed Central

    Stránský, Petr; Klečka, Jiří; Trávníček, Ivan; Ürge, Tomáš; Eret, Viktor; Ferda, Jiří; Petersson, Fredrik; Hes, Ondřej

    2012-01-01

    Introduction Urine leakage following laparoscopic radical prostatectomy (LRP) is a possible complication that may herald chronic urine incontinence. Intraoperative measures aiming to prevent this is not standardised. Aim Presentation of experience with active suction of the prevesical space in managing postoperative urine leakage. Material and methods At the Department of Urology, where laparoscopy of the upper abdomen and open RP were performed, a protocol for extraperitoneal LRP was established in 8/2008. Until 5/2011, 154 LRPs have been performed. Urine leakage from a suction drain appeared in 9 cases (5.8%). Permanent active suction (with a machine for Büllae thoracic drainage) of the prevesical space with negative pressure of 7-12 cm of H2O was started immediately. Results Urine leakage started after a mean of 0.9 (0-2) days postoperatively and stopped after a mean of 8.1 (15-42) days. Leakage stopped with only suctioning in 7 cases. In one case, open re-anastomosis was performed on the 7th postoperative day (POD). In another case, ineffective active suction was replaced on the 10th POD by needle vented suction without effect and the leakage stopped following gradual shortening of the drain up to the 15th POD. Conclusions Active suction of the prevesical space seems to be an effective intervention to stop postoperative urine leakage after laparoscopic radical prostatectomy. PMID:23630554

  14. A computed tomographic scan assessment of endotracheal suctioning-induced bronchoconstriction in ventilated sheep.

    PubMed

    Lu, Q; Capderou, A; Cluzel, P; Mourgeon, E; Abdennour, L; Law-Koune, J D; Straus, C; Grenier, P; Zelter, M; Rouby, J J

    2000-11-01

    This study was directed at assessing changes in bronchial cross-sectional surface areas (BCSA) and in respiratory resistance induced by endotracheal suctioning in nine anesthetized sheep. Cardiorespiratory parameters (Swan-Ganz catheter), respiratory resistance (inspiratory occlusion technique), BCSA, and lung aeration (computed tomography) were studied at baseline, during endotracheal suctioning, and after 20 consecutive hyperinflations. Measurements performed initially at an inspired oxygen fraction (FI(O(2))) of 0.3 were repeated at an FI(O(2)) of 1.0. At an FI(O(2)) of 0.3, endotracheal suctioning resulted in atelectasis, a reduction in BCSA of 29 +/- 23% (mean +/- SD), a decrease in arterial oxygen saturation from 95 +/- 3% to 87 +/- 12% (p = 0.02), an increase in venous admixture from 19 +/- 10% to 31 +/- 19% (p = 0. 006), and an increase in lung tissue resistance (DR(rs)) (p = 0. 0003). At an FI(O(2)) of 1.0, despite an extension of atelectasis and an increase in pulmonary shunt from 19 +/- 5% to 36 +/- 2% (p < 0.0001), arterial O(2) desaturation was prevented and BCSA decreased by only 7 +/- 32%. A recruitment maneuver after endotracheal suctioning entirely reversed the suctioning-induced increase in DR(rs) and atelectasis. In three lidocaine-pretreated sheep, the endotracheal suctioning-induced reduction of BCSA was entirely prevented. These data suggest that the endotracheal suctioning-induced decrease in BCSA is related to atelectasis and bronchoconstriction. Both effects can be reversed by hyperoxygenation maneuver before suctioning in combination with recruitment maneuver after suctioning.

  15. Review of Suction Water Content Relationship of Bentonite-Sand Mixtures Considering Temperature Effects

    NASA Astrophysics Data System (ADS)

    Rawat, Abhishek; Zhi Lang, Lin; Baille, Wiebke

    2015-04-01

    Bentonite-sand mixture is one of the candidate sealing/ buffer material for landfills, hazardous and high level radioactive waste repository. The long term satisfactory performance of bentonite sand mixture in terms of load bearing function, sealing function and buffer function is governed by hydro-mechanical response of material under elevated temperature conditions. The suction-water content relationship is one of the key parameter, which govern the thermo-hydro-mechanical behavior of compacted bentonite-sand mixture. This paper presents brief review of suction water content relationships of bentonite-sand mixture considering temperature effects. Numerous parametric models or equations have been developed for representing the soil water characteristics curve i.e. SWCC for isothermal conditions. The most frequently used equations for representing the SWCC are the van Genuchten (1980) and Fredlund and Xing (1994) SWCC equations. Various researchers (Romero et al. 2000; Villar and Lloret, 2004; Tang and Cui, 2005; Agus, 2005; Arifin, 2008) have reported the temperature effect on the water retention behavior of compacted bentonite-sand mixtures. The testing program, results and major conclusions made by above mentioned researchers were discussed in this paper. The changes in hydro-mechanical behavior due to elevated temperature are also discussed based on the suction components of soil which are influenced by temperature. As a general conclusion, total suction of the bentonite-sand mixtures is a function of mixture water content and mixture bentonite content or collectively a function of bentonite water content both at room temperature and at elevated temperature. At a constant temperature, different techniques for measuring suction results in different values of suction depending on accuracy of the sensor and calibration technique used as founded earlier by Agus (2005). The change in total suction due to change in temperature lower than 100 degree C is reversible

  16. City Fishing.

    ERIC Educational Resources Information Center

    Lange, Robert E.

    1979-01-01

    A program of supplying opportunities for fishing at locations within and near urban areas was developed. This effort included stocking, management of bodies of water for fishing, and presentation of fishing clinics for urban fishermen. (RE)

  17. Fish Hearing.

    ERIC Educational Resources Information Center

    Blaxter, J. H. S.

    1980-01-01

    Provides related information about hearing in fish, including the sensory stimulus of sound in the underwater environment, mechanoreceptors in fish, pressure perception and the swimbladder, specializations in sound conduction peculiar to certain fish families. Includes numerous figures. (CS)

  18. Determination of sulfadiazine, trimethoprim, and N(4) -acetyl-sulfadiazine in fish muscle plus skin by Liquid Chromatography-Mass Spectrometry. Withdrawal-time calculation after in-feed administration in gilthead sea bream (Sparus aurata L.) fed two different diets.

    PubMed

    Zonaras, V; Tyrpenou, A; Alexis, M; Koupparis, M

    2016-10-01

    This study presents a depletion study for sulfadiazine and trimethoprim in muscle plus skin of gilthead sea bream (Sparus aurata L.). N(4) -acetyl-sulfadiazine, the main metabolite of sulfadiazine (SDZ), was also examined. The fish were held in seawater at a temperature of 24-26 °C. SDZ and trimethoprim (TMP) were administered orally with medicated feed for five consecutive days at daily doses of 25 mg SDZ and 5 mg TMP per kg of fish body weight per day. Two different diets, fish oil- and plant oil-based diets, were investigated. Ten fish were sampled at each of the days 1, 3, 5, 6, 8, 9, 10, and 12 after the start of veterinary medicine administration. However for the calculation of the withdrawal periods, sampling day 1 was set as 24 h after the last dose of the treatment. Fish samples were analyzed for SDZ, TMP, and acetyl-sulfadiazine (AcSDZ) residues by liquid chromatography-mass spectrometry. SDZ and TMP concentrations declined rapidly from muscle plus skin. Considering a maximum residue limit of 100 μg/kg for the total of sulfonamides and 50 μg/kg for TMP residues in fish muscle plus skin, the withdrawal periods of the premix trimethoprim-sulfadiazine 50% were calculated as 5 and 6 days, at 24-26 °C, in fish oil (FO) and plant oil (PO) groups, respectively. The investigation of this work is important to protect consumers by controlling the undesirable residues in fish.

  19. Determination of sulfadiazine, trimethoprim, and N(4) -acetyl-sulfadiazine in fish muscle plus skin by Liquid Chromatography-Mass Spectrometry. Withdrawal-time calculation after in-feed administration in gilthead sea bream (Sparus aurata L.) fed two different diets.

    PubMed

    Zonaras, V; Tyrpenou, A; Alexis, M; Koupparis, M

    2016-10-01

    This study presents a depletion study for sulfadiazine and trimethoprim in muscle plus skin of gilthead sea bream (Sparus aurata L.). N(4) -acetyl-sulfadiazine, the main metabolite of sulfadiazine (SDZ), was also examined. The fish were held in seawater at a temperature of 24-26 °C. SDZ and trimethoprim (TMP) were administered orally with medicated feed for five consecutive days at daily doses of 25 mg SDZ and 5 mg TMP per kg of fish body weight per day. Two different diets, fish oil- and plant oil-based diets, were investigated. Ten fish were sampled at each of the days 1, 3, 5, 6, 8, 9, 10, and 12 after the start of veterinary medicine administration. However for the calculation of the withdrawal periods, sampling day 1 was set as 24 h after the last dose of the treatment. Fish samples were analyzed for SDZ, TMP, and acetyl-sulfadiazine (AcSDZ) residues by liquid chromatography-mass spectrometry. SDZ and TMP concentrations declined rapidly from muscle plus skin. Considering a maximum residue limit of 100 μg/kg for the total of sulfonamides and 50 μg/kg for TMP residues in fish muscle plus skin, the withdrawal periods of the premix trimethoprim-sulfadiazine 50% were calculated as 5 and 6 days, at 24-26 °C, in fish oil (FO) and plant oil (PO) groups, respectively. The investigation of this work is important to protect consumers by controlling the undesirable residues in fish. PMID:26987772

  20. Theoretical investigation of maintaining the boundary layer of revolution laminar using suction slits in incompressible flow

    NASA Technical Reports Server (NTRS)

    Thiede, P.

    1978-01-01

    The transition of the laminar boundary layer into the turbulent state, which results in an increased drag, can be avoided by sucking of the boundary layer particles near the wall. The technically-interesting case of sucking the particles using individual slits is investigated for bodies of revolution in incompressible flow. The results of the variational calculations show that there is an optimum suction height, where the slot separations are maximum. Combined with favorable shaping of the body, it is possible to keep the boundary layer over bodies of revolution laminar at high Reynolds numbers using relatively few suction slits and small amounts of suction flow.

  1. A law of the wall for turbulent boundary layers with suction: Stevenson's formula revisited

    NASA Astrophysics Data System (ADS)

    Vigdorovich, Igor

    2016-08-01

    The turbulent velocity field in the viscous sublayer of the boundary layer with suction to a first approximation is homogeneous in any direction parallel to the wall and is determined by only three constant quantities — the wall shear stress, the suction velocity, and the fluid viscosity. This means that there exists a finite algebraic relation between the turbulent shear stress and the longitudinal mean-velocity gradient, using which as a closure condition for the equations of motion, we establish an exact asymptotic behavior of the velocity profile at the outer edge of the viscous sublayer. The obtained relationship provides a generalization of the logarithmic law to the case of wall suction.

  2. Feeding Tubes

    MedlinePlus

    ... administer the TPN. Tubes Used for Enteral Feeds NG (Nasogastric Tube) A flexible tube is placed via ... down through the esophagus into the stomach. The NG tube can be used to empty the stomach ...

  3. 7 CFR 1437.303 - Aquaculture, including ornamental fish.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 10 2013-01-01 2013-01-01 false Aquaculture, including ornamental fish. 1437.303... ASSISTANCE PROGRAM Determining Coverage Using Value § 1437.303 Aquaculture, including ornamental fish. (a... human consumption as determined by CCC. (2) Fish raised as feed for other fish that are consumed...

  4. 7 CFR 1437.303 - Aquaculture, including ornamental fish.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Aquaculture, including ornamental fish. 1437.303... ASSISTANCE PROGRAM Determining Coverage Using Value § 1437.303 Aquaculture, including ornamental fish. (a... human consumption as determined by CCC. (2) Fish raised as feed for other fish that are consumed...

  5. Feed Fish Effluent and Reel in Savings

    ERIC Educational Resources Information Center

    Wert, Frank S.; Henderson, Upton B.

    1978-01-01

    Discusses the ways in which aquaculture can be a cost-effective wastewater treatment alternative. Fifteen strategies were selected as being appropriate and technologically feasible wastewater treatment systems to compare for the size of community under consideration. Costs for each stage of each strategy were estimated and compared. (Author/MA)

  6. Calculation of vortex lift effect for cambered wings by the suction analogy

    NASA Technical Reports Server (NTRS)

    Lan, C. E.; Chang, J. F.

    1981-01-01

    An improved version of Woodward's chord plane aerodynamic panel method for subsonic and supersonic flow is developed for cambered wings exhibiting edge separated vortex flow, including those with leading edge vortex flaps. The exact relation between leading edge thrust and suction force in potential flow is derived. Instead of assuming the rotated suction force to be normal to wing surface at the leading edge, new orientation for the rotated suction force is determined through consideration of the momentum principle. The supersonic suction analogy method is improved by using an effective angle of attack defined through a semi-empirical method. Comparisons of predicted results with available data in subsonic and supersonic flow are presented.

  7. Shock wave boundary layer interaction on suction side of compressor profile in single passage test section

    NASA Astrophysics Data System (ADS)

    Flaszynski, Pawel; Doerffer, Piotr; Szwaba, Ryszard; Kaczynski, Piotr; Piotrowicz, Michal

    2015-11-01

    The shock wave boundary layer interaction on the suction side of transonic compressor blade is one of the main objectives of TFAST project (Transition Location Effect on Shock Wave Boundary Layer Interaction). In order to investigate the flow structure on the suction side of a profile, a design of a generic test section in linear transonic wind tunnel was proposed. The experimental and numerical results for the flow structure investigations are shown for the flow conditions as the existing ones on the suction side of the compressor profile. Near the sidewalls the suction slots are applied for the corner flow structure control. It allows to control the Axial Velocity Density Ratio (AVDR), important parameter for compressor cascade investigations. Numerical results for Explicit Algebraic Reynolds Stress Model with transition modeling are compared with oil flow visualization, schlieren and Pressure Sensitive Paint. Boundary layer transition location is detected by Temperature Sensitive Paint.

  8. Evidence-based guideline for suctioning the intubated neonate and infant.

    PubMed

    Gardner, Denice L; Shirland, Lee

    2009-01-01

    The endotracheal tube (ETT) is the most common artificial airway used in NICUs. Suctioning of the ETT is imperative to maintain patency and prevent complications. An extensive review of the literature revealed a lack of standardized criteria or guidelines for suctioning the ETT of neonates and infants in the NICU. The purpose of this article is to report the implementation of an evidence-based guideline that can be utilized in NICU care.

  9. Numerical Studies on a Rotor with Distributed Suction for Noise Reduction

    NASA Astrophysics Data System (ADS)

    Lutz, Thorsten; Arnold, Benjamin; Wolf, Alexander; Krämer, Ewald

    2014-06-01

    Minimizing the flow-induced noise is an important issue in the design of modern onshore wind turbines. There is a number of proven passive means to reduce the aeroacoustic noise, such as the implementation of serrations, porous trailing edges or the aeroacoustic airfoil design. The noise emission can be further reduced by active flow control techniques. In the present study the impact of distributed boundary layer suction on the noise emission of an airfoil and a complete rotor is investigated. Aerodynamic and aeroacoustic wind tunnel tests were performed for the NACA 64-418 airfoil and supplemented by numerical calculations. The aeroacoustic analyses have been conducted by means of the institute's Rnoise prediction scheme. The 2D studies have shown that noise reductions of 5 dB can be achieved by suction at moderate mass flow rates. To study the impact of three-dimensional effects numerical investigations have been conducted on the example of the generic NREL 5MW rotor with suction applied in the outer part of the blade. The predictions for the complete rotor provided smaller benefits compared to those for the isolated airfoil, mainly because the examined suction configurations were not optimized with respect to the extent of the suction patch and suction distribution.

  10. Design and experimental performance of short curved wall diffusers with axial symmetry utilizing slot suction

    NASA Technical Reports Server (NTRS)

    Yang, T.; Hudson, W. G.; Nelson, C. D.

    1973-01-01

    The feasibility of designing short curved wall axially symmetrical subsonic diffusers utilizing suction through slots in the diffuser walls to prevent flow separation was investigated. A potential flow analysis was made, and a digital computer program was written for determining the diffuser wall contour for prescribed boundary conditions. The flow field included branch flow so that the suction slot geometry could be a part of the diffuser design. One bell shaped diffuser and three annular diffusers with area ratios of either 2.5:1 or 3:1 were designed, fabricated, and tested. Minimum suction requirements of metastable operation ranged from 6.3 percent to 12 percent when operating with inlet air velocities in the 1000 to 250 ft/sec (30 to 76 m/sec) range. For stable operation suction rates from 10 percent to 22 percent were required. In all cases the diffuser effectiveness was above 95 percent based on the conventional definition, and from 81 percent to 94 percent when the suction loss was accounted for. The exit velocity profiles were virtually flat with no more than + or - 9% variation over 95 percent of the exit area when operated with sufficient suction to prevent flow separation.

  11. Performance of a short annular dump diffuser using wall trailing-edge suction

    NASA Technical Reports Server (NTRS)

    Juhasz, A. J.

    1974-01-01

    A short annular dump (abrupt flow area change) diffuser was tested with suction through wall trailing-edge slots at inlet Mach numbers of 0.19 and 0.27 and at near ambient inlet temperature and pressure, with suction flow varied from zero to 10 percent of the inlet air mass-flow rate. The overall ratio of diffuser exit area to inlet area was 4.0, and the ratio of length to inlet height was 2.0. By applying suction flow separately on either wall or to both walls simultaneously, the original annular jet profile could be altered to either a hub- or tip-biased profile. Diffuser effectiveness was increased from about 25 percent with no suction to 50 percent at 6 percent outer-wall suction and to 52 percent at a combined suction rate on both walls of 10.25 percent. At the same time, diffuser total pressure loss was reduced by one-fourth.

  12. Influence of suction cycles on the soil fabric of compacted swelling soil

    NASA Astrophysics Data System (ADS)

    Nowamooz, Hossein; Masrouri, Farimah

    2010-12-01

    The soil fabric plays an important role in complex hydromechanical behaviour of the expansive soils. This article addresses the influence of the wetting and drying paths on the soil fabric of compacted bentonite and silt mixtures at two different initial dry densities corresponding to loose and dense states. To obtain the hydric response of the soil, two suction imposition techniques were used: osmotic technique for the suction range less than 8.5 MPa and the vapour equilibrium or the salt solution technique for the suction range between 8.5 and 287.9 MPa. Additionally, the soil fabric analysis was performed using mercury intrusion porosimetry (MIP) and nitrogen gas adsorption (BET) techniques. The dense samples produced cumulative swelling strains during the suction cycles, while shrinkage was observed for the loose samples. The suction cycles induced an equilibrium state indicative of the elastic behaviour of the samples. The soil fabric analysis showed that regardless of the soil's initial state (loose or dense), the samples obtained the same soil fabric at the equilibrium state. The experimental results illustrated also the existence of an elastic void ratio ( e0el) where the compacted soils at this state present an elastic hydric behaviour during the successive suction cycles.

  13. The role of subgaleal suction drain placement in chronic subdural hematoma evacuation

    PubMed Central

    Yadav, Yad Ram; Parihar, Vijay; Chourasia, Ishwar D.; Bajaj, Jitin; Namdev, Hemant

    2016-01-01

    Introduction: There is lack of uniformity about the preferred surgical treatment, role of drain, and type of drain among various surgeons in chronic subdural hematoma (CSDH). The present study is aimed to evaluate role of subgaleal drain. Materials and Methods: This was a prospective study of 260 patients of CSDH treated surgically. Burr-hole irrigation with and without suction drain was done in 140 and 120 patients, respectively. Out of 120 patients without suction drain 60 each were managed by single and two burr holes. Pre- and postoperative GCS was recorded. Recurrent hematomas, CSDH secondary to tumor, due to intracranial hypotension, coagulopathy, children below 18 years, and patients treated by twist drill craniostomy or craniotomy were excluded. Subgaleal closed-system drainage with low negative pressure was used. Results: Age of the patients ranged from 18 to 75 years with mean age of 57 years. There were 9, 47, 204 patients in GCS of 3-8, 9-12, and 13-15, respectively. Both the groups were comparable in terms of age, etiology, gender, and neurological status. There was no difference in the mortality in both the group. The recurrence and postoperative pneumocephalus was significantly less in suction drain group as compared to without drain group. There was no infection or any other complication related to suction drainage. Conclusion: Subgaleal closed suction drainage was safe, simple, and effective in the management of CSDH. Recurrence rate was low in the suction drain group. PMID:27366247

  14. A Morphospace for Reef Fishes: Elongation Is the Dominant Axis of Body Shape Evolution

    PubMed Central

    Claverie, Thomas; Wainwright, Peter C.

    2014-01-01

    Tropical reef fishes are widely regarded as being perhaps the most morphologically diverse vertebrate assemblage on earth, yet much remains to be discovered about the scope and patterns of this diversity. We created a morphospace of 2,939 species spanning 56 families of tropical Indo-Pacific reef fishes and established the primary axes of body shape variation, the phylogenetic consistency of these patterns, and whether dominant patterns of shape change can be accomplished by diverse underlying changes. Principal component analysis showed a major axis of shape variation that contrasts deep-bodied species with slender, elongate forms. Furthermore, using custom methods to compare the elongation vector (axis that maximizes elongation deformation) and the main vector of shape variation (first principal component) for each family in the morphospace, we showed that two thirds of the families diversify along an axis of body elongation. Finally, a comparative analysis using a principal coordinate analysis based on the angles among first principal component vectors of each family shape showed that families accomplish changes in elongation with a wide range of underlying modifications. Some groups such as Pomacentridae and Lethrinidae undergo decreases in body depth with proportional increases in all body regions, while other families show disproportionate changes in the length of the head (e.g., Labridae), the trunk or caudal region in all combinations (e.g., Pempheridae and Pinguipedidae). In conclusion, we found that evolutionary changes in body shape along an axis of elongation dominates diversification in reef fishes. Changes in shape on this axis are thought to have immediate implications for swimming performance, defense from gape limited predators, suction feeding performance and access to some highly specialized habitats. The morphological modifications that underlie changes in elongation are highly diverse, suggesting a role for a range of developmental processes

  15. Breast Feeding.

    ERIC Educational Resources Information Center

    International Children's Centre, Paris (France).

    This set of documents consists of English, French, and Spanish translations of four pamphlets on breast-feeding. The pamphlets provide information designed for lay persons, academics and professionals, health personnel and educators, and policy-makers. The contents cover health-related differences between breast and bottle milk; patterns of…

  16. Tube Feedings.

    ERIC Educational Resources Information Center

    Plummer, Nancy

    This module on tube feedings is intended for use in inservice or continuing education programs for persons who work in long-term care. Instructor information, including teaching suggestions and a listing of recommended audiovisual materials and their sources appear first. The module goal and objectives are then provided. A brief discussion follows…

  17. Application of food waste based diets in polyculture of low trophic level fish: effects on fish growth, water quality and plankton density.

    PubMed

    Mo, Wing Yin; Cheng, Zhang; Choi, Wai Ming; Man, Yu Bon; Liu, Yihui; Wong, Ming Hung

    2014-08-30

    Food waste was collected from local hotels and fish feed pellets were produced for a 6 months long field feeding trial. Three types of fish feed pellets (control diet: Jinfeng® 613 formulated feed, contains mainly fish meal, plant product and fish oil; Diet A: food waste based diet without meat and 53% cereal; Diet B: food waste based diet with 25% meat and 28% cereal) were used in polyculture fish ponds to investigate the growth of fish (grass carp, bighead and mud carp), changes in water quality and plankton density. No significant differences in the levels of nitrogen and phosphorous compounds of water body were observed between 3 fish ponds after the half-year feeding trial, while pond receiving Diet A had the highest density of plankton. The food waste combination of Diet B seems to be a better formulation in terms of the overall performance on fish growth.

  18. Application of food waste based diets in polyculture of low trophic level fish: effects on fish growth, water quality and plankton density.

    PubMed

    Mo, Wing Yin; Cheng, Zhang; Choi, Wai Ming; Man, Yu Bon; Liu, Yihui; Wong, Ming Hung

    2014-08-30

    Food waste was collected from local hotels and fish feed pellets were produced for a 6 months long field feeding trial. Three types of fish feed pellets (control diet: Jinfeng® 613 formulated feed, contains mainly fish meal, plant product and fish oil; Diet A: food waste based diet without meat and 53% cereal; Diet B: food waste based diet with 25% meat and 28% cereal) were used in polyculture fish ponds to investigate the growth of fish (grass carp, bighead and mud carp), changes in water quality and plankton density. No significant differences in the levels of nitrogen and phosphorous compounds of water body were observed between 3 fish ponds after the half-year feeding trial, while pond receiving Diet A had the highest density of plankton. The food waste combination of Diet B seems to be a better formulation in terms of the overall performance on fish growth. PMID:24492151

  19. Scaling of in vivo muscle velocity during feeding in the largemouth bass, Micropterus salmoides (Centrarchidae).

    PubMed

    Carroll, Andrew M; Wainwright, Peter C

    2011-01-01

    Many vertebrates undergo large increases in body size over the course of a lifetime, and these increases are often accompanied by changes in morphological and physiological parameters. For instance, in most animals, increases in size with growth are accompanied by decreases in the maximum speed of shortening (V(max)) in locomotor muscles. Curiously, in muscles involved in suction feeding, V(max) shows no decreases with size in vitro, despite the fact that timing of kinematic events involved in suction feeding (e.g., time to peak gape) slow with increased size. The goal of this study was to examine whether muscular speed in vivo varies with size during suction feeding in the largemouth bass (Micropterus salmoides). The dorsal epaxial musculature of 10 individual bass (varying from 123 to 685 g and from 18.1 to 32.0 cm standard length [SL]) was implanted with sonometric crystals to measure muscle length during feeding on elusive prey (large goldfish). No relationship was found between the mean individual or maximum speed of shortening with mean individual log-transformed SL. However, mean magnitude of shortening and maximum shortening magnitude showed nonsignificant increases with SL ([Formula: see text] and 0.06, respectively). Average duration of shortening was found to increase with log-transformed SL. The size invariance of observed shortening velocity in the epaxial muscles during feeding may stem from size invariance of imposed loads during suction feeding. This is in contrast to what is normally seen in locomotor systems where loads on muscles often increase with body size. PMID:22030854

  20. Scaling of in vivo muscle velocity during feeding in the largemouth bass, Micropterus salmoides (Centrarchidae).

    PubMed

    Carroll, Andrew M; Wainwright, Peter C

    2011-01-01

    Many vertebrates undergo large increases in body size over the course of a lifetime, and these increases are often accompanied by changes in morphological and physiological parameters. For instance, in most animals, increases in size with growth are accompanied by decreases in the maximum speed of shortening (V(max)) in locomotor muscles. Curiously, in muscles involved in suction feeding, V(max) shows no decreases with size in vitro, despite the fact that timing of kinematic events involved in suction feeding (e.g., time to peak gape) slow with increased size. The goal of this study was to examine whether muscular speed in vivo varies with size during suction feeding in the largemouth bass (Micropterus salmoides). The dorsal epaxial musculature of 10 individual bass (varying from 123 to 685 g and from 18.1 to 32.0 cm standard length [SL]) was implanted with sonometric crystals to measure muscle length during feeding on elusive prey (large goldfish). No relationship was found between the mean individual or maximum speed of shortening with mean individual log-transformed SL. However, mean magnitude of shortening and maximum shortening magnitude showed nonsignificant increases with SL ([Formula: see text] and 0.06, respectively). Average duration of shortening was found to increase with log-transformed SL. The size invariance of observed shortening velocity in the epaxial muscles during feeding may stem from size invariance of imposed loads during suction feeding. This is in contrast to what is normally seen in locomotor systems where loads on muscles often increase with body size.

  1. An analysis of quantitative measurements of drainage exudate using negative suction in 96 microtia ear reconstructions

    PubMed Central

    Xu, Zhicheng; Zhang, Ruhong; Zhang, Qun; Xu, Feng

    2012-01-01

    Negative suction drainage is commonly used for the prevention of seromas or hematomas in auricular reconstruction surgery; however, there are few reports regarding the quantitative measurement of negative suction and its relation to disposed time, patient age or microtia type. In the present study, the authors recorded the volume of suction exudate in microtia reconstruction and elaborate on the relevant details of controlling negative suction. A negative suction drainage system was applied in 96 microtia patients between 2007 and 2010. Two small polyethylene drains were inserted adjacent to the concha and the scapha, respectively. The volume of exudate was recorded for three days after surgery and was analyzed according to disposed time, patient age and microtia type. The drains were removed on the third postoperative day, when only a small amount of exudate remained. A significant change in drainage was observed over three days postoperatively, and the quantity decreased progressively on the third postoperative day. Comparison of age groups showed that the volume of drainage from adults was greater than that from children or adolescents in the first two postoperative days, regardless of whether the drains were inserted in the scapha or concha. No statistical differences were found on the third postoperative day. A comparison of drain types revealed no statistically significant differences between scapha and concha drains three days postoperatively. The analysis demonstrated that drainage quantity is related to disposed time and patient age, but not to microtia type. The authors recommend removal of suction drains on the third postoperative day. Moreover, individualized negative suction treatment according to age or microtia type provides a safe and consistent approach to achieving acceptable results and fewer complications. PMID:24294013

  2. Boundary layer modification by means of wall suction and the effect on the wake behind a rectangular forebody

    NASA Astrophysics Data System (ADS)

    Trip, Renzo; Fransson, Jens H. M.

    2014-12-01

    The wake characteristics of a two-dimensional rectangular forebody with a smooth leading edge and a blunt trailing edge are investigated. Wall suction is applied along the forebody in order to modify the developing boundary layer. An initially laminar boundary layer subject to suction yields an asymptotic suction boundary layer at the trailing edge of the body, whereas a high enough suction coefficient relaminarizes an initially turbulent boundary layer. The critical suction velocity required to achieve this significant modification of the boundary layer properties is typically in the order of 1% of the free-stream velocity, where the critical suction coefficient depends on the Reynolds number. We show that a thinner boundary layer induces a higher vortex shedding frequency and a lower base pressure. Furthermore, the boundary layer state, laminar or turbulent, has a significant influence on the wake. For example, the Strouhal number based on the effective body thickness is being reduced by 25% from laminar to turbulent inlet conditio