Science.gov

Sample records for suction feeding fishes

  1. 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.

  2. 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. © The Author 2015. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. 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. © The Author 2015. Published by Oxford University Press

  11. 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.

  12. 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

    2015-05-07

    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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. 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

  14. Kinematics of suction feeding in the seahorse Hippocampus reidi.

    PubMed

    Roos, Gert; Van Wassenbergh, Sam; Herrel, Anthony; Aerts, Peter

    2009-11-01

    Fish typically use a rostro-caudal wave of head expansion to generate suction, which is assumed to cause a uni-directional, anterior-to-posterior flow of water in the expanding head. However, compared with typical fish, syngnathid fishes have a remarkably different morphology (elongated snout, small hyoid, immobile pectoral girdle) and feeding strategy (pivot feeding: bringing the small mouth rapidly close to the prey by neurocranial dorsorotation). As a result, it is unclear how suction is generated in Syngnathidae. In this study, lateral and ventral expansions of the head were quantified in Hippocampus reidi and linked to the kinematics of the mouth, hyoid and neurocranium. In addition, the flow velocities inside the bucco-pharyngeal cavity and in front of the mouth were calculated. Our data suggest that the volume changes caused by lateral expansion are dominant over ventral expansion. Maximum gape, neurocranium rotation and hyoid depression are all reached before actual volume increase and before visible prey movement. This implies that, unlike previously studied teleosts, hyoid rotation does not contribute to ventral expansion by lowering the floor of the mouth during prey capture in H. reidi. The lateral volume changes show a rostro-caudal expansion, but the maximal flow velocity is not near the mouth aperture (as has been demonstrated for example in catfish) but at the narrow region of the buccal cavity, dorsal to the hyoid.

  15. No trade-off between biting and suction feeding performance in clariid catfishes.

    PubMed

    Van Wassenbergh, Sam; Herrel, Anthony; Adriaens, Dominique; Aerts, Peter

    2007-01-01

    It is generally assumed that biting performance trades off with suction performance in fish because both feeding types may place conflicting demands on the cranial musculo-skeletal system. However, the functional consequences of morphological adaptations enhancing biting on the mechanics and performance of suction feeding in fish remain obscure. In this study, suction feeding performance was compared between three clariid catfish species differing considerably in their biting capacity, by measuring the velocity of a standardized prey being sucked into the buccal cavity using high-speed cineradiography. In addition, buccal volume changes during prey capture were quantified by ellipse modelling. As all species were able to accelerate the prey to similar peak velocities, our results demonstrate the possibility for catfishes to increase bite performance considerably without compromising suction performance. The amount of buccal expansion in the ventral direction is approximately equal for all species. Consequently, the system generating expansion through ventral rotation of the lower jaw, hyoid and pectoral girdle is apparently not constrained (mechanically or architectonically) by the hypertrophy of the jaw adductors. As the effect of a reduced magnitude of lateral expansion (suspensorium abduction) on suction performance in Clariidae appears to be negligible (for example in Gymnallabes typus), these data demonstrate the dominant role of ventral expansion for producing suction in these fish.

  16. Effect of Feeding and Suction on Gastric Impedance Spectroscopy Measurements.

    PubMed

    Beltran, Nohra E; Sánchez-Miranda, Gustavo; Sacristan, Emilio

    2015-01-01

    A specific device and system has been developed and tested for clinical monitoring of gastric mucosal reactance in the critically ill as an early warning of splanchnic hypoperfusion associated with shock and sepsis. This device has been proven effective in clinical trials and is expected to become commercially available next year. The system uses a combination nasogastric tube and impedance spectroscopy probe as a single catheter. Because this device has a double function, the question is: Does enteral feeding or suction affect the gastric reactance measurements? This study was designed to evaluate the effect of feeding and suction on the measurement of gastric impedance spectroscopy in healthy volunteers. Impedance spectra were obtained from the gastric wall epithelia of 18 subjects. The spectra were measured for each of the following conditions: postinsertion of gastric probe, during active suction, postactive suction, and during enteral feeding (236 ml of nutritional supplement). Impedance spectra were reproducible in all volunteers under all conditions tested. There was a slight increase in impedance parameters after suction, and a decrease in impedance after feeding; however, these observed differences were insignificant compared to patient-to-patient variability, and truly negligible compared with previously observed changes associated with splanchnic ischemia in critically ill patients. Our results demonstrate that suction or feeding when using the impedance spectro-metry probe/nasogastric tube does not significantly interfere with gastric impedance spectrometer measurements.

  17. 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

  18. 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

  19. Muscle function and power output during suction feeding in largemouth bass, Micropterus salmoides.

    PubMed

    Carroll, Andrew M; Wainwright, Peter C

    2006-03-01

    Muscle power output is thought to limit suction feeding performance, yet muscle power output during suction feeding has never been directly measured. In this study, epaxial activation and strain, hyoid depression, and intra-oral pressure were simultaneously measured during suction feeding in the largemouth bass (Micropterus salmoides). A mechanical model of muscle force transmission between the neurocranium and oral cavity was used to estimate muscle stress, work, and power. The epaxials shortened from rest an average of 9% of their length, with the highest efforts producing greater than 20% strain. Onset of shortening was simultaneous with or shortly after (< 10 ms) onset of activation. Maximal net power for individual fish ranged from 17 to 137 W kg(-1). Muscle power was significantly correlated with rectified EMG area (r = 0.80; p < 0.0001). The power required for cranial expansion was significantly correlated with epaxial power (r = 0.81; p < 0.0001), and the power exponent of this relationship ( approximately 1 for 3 of the 4 fish) implies that epaxial power accounts for most of the power of cranial expansion. The limitations imposed by the kinematic requirements and loading environment of suction feeding (short delay between activation and strain, maximal stress occurring after shortening, operation at lengths shorter than resting length) may prevent maximal muscular power production.

  20. 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.

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

    PubMed

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

    2012-08-07

    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.

  2. 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

  3. 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.

  4. Kinematics of benthic suction feeding in Callichthyidae and Mochokidae, with functional implications for the evolution of food scraping in catfishes.

    PubMed

    Van Wassenbergh, Sam; Lieben, Tim; Herrel, Anthony; Huysentruyt, Frank; Geerinckx, Tom; Adriaens, Dominique; Aerts, Peter

    2009-01-01

    Food scraping has independently evolved twice from suction feeding in the evolution of catfishes: within neotropical Loricarioidea and paleotropical Mochokidae. To gain insight in the evolutionary transitions associated with the evolution towards scraping, we analyzed prey capture kinematics in two species of benthic suction feeders which belong to taxa that are closely related to the scraper lineages (respectively, Corydoras splendens and Synodontis multipunctatus), and compared it to prey capture in a more distantly related, generalist suction feeder (Clarias gariepinus). Simultaneous ventral and lateral view high-speed videos were recorded to quantify the movements of the lower jaw, hyoid, pectoral girdle and neurocranium. Additionally, ellipse modeling was applied to relate head shape differences to buccal expansion kinematics. Similarly to what has been observed in scrapers, rotations of the neurocranium are minimal in the benthic suction feeders, and may consequently have facilitated the evolution of a scraping feeding mechanism. The hypothesis that fish with a more laterally compressed head rely more heavily on lateral expansion of the buccal cavity to generate suction, was confirmed in our sample of catfish species. Since an important contribution of lateral expansion of the head to suction may avoid the need for a strong, ventral depression of the mouth floor during feeding, we hypothesized that this may have allowed a closer association with the substrate in the ancestors of scrapers. However, our hypothesis was not supported by an ancestral state reconstruction, which suggests that scraping probably evolved from sub-terminal mouthed ancestors with dorsoventrally flattened heads.

  5. Feeding kinematics, suction and hydraulic jetting capabilities in bearded seals (Erignathus barbatus).

    PubMed

    Marshall, Christopher D; Kovacs, Kit M; Lydersen, Christian

    2008-03-01

    Feeding kinematics, suction and hydraulic jetting capabilities of bearded seals (Erignathus barbatus) were characterized during controlled feeding trials. Feeding trials were conducted both on land and in water, and allowed a choice between suction and biting, but food was also presented that could be ingested by suction alone. Four feeding phases, preparatory, jaw opening, hyoid depression and jaw closing were observed; the mean feeding cycle duration was 0.54+/-0.22 s, regardless of feeding mode (P>0.05). Subjects feeding on land used biting and suction 89.3% and 10.7% of the time, respectively. Subjects feeding in water used suction and hydraulic jetting 96.3% and 3.7% of the time, respectively. No biting behavior was observed underwater. Suction feeding was characterized by a small gape (2.7+/-0.85 cm), small gape angle (24.4+/-8.13 degrees ), pursing of the rostral lips to form a circular aperture, and pursing of the lateral lips to occlude lateral gape. Biting was characterized by large gape (7.3+/-2.2 cm), large gape angle (41.7+/-15.2 degrees ), and lip curling to expose the teeth. An excavation behavior in which suction and hydraulic jetting were alternated was used to extract food from recessed wells. The maximum subambient and suprambient pressures recorded were 91.2 and 53.4 kPa, respectively. The inclusion of suction data for phocids broadens the principle that suction feeding kinematics is conserved among aquatic vertebrates. Furthermore, bearded seals support predictions that mouth size, fluid flow speed, and elusiveness of prey consumed are among a suite of traits that determine the specific nature of suction feeding among species.

  6. 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

  7. Sensory-Motor Systems of Copepods involved in their Escape from Suction Feeding.

    PubMed

    Yen, Jeannette; Murphy, David W; Fan, Lin; Webster, Donald R

    2015-07-01

    Copepods escape well by detecting minute gradients in the flow field; they react quickly, and swim away strongly. As a key link in the aquatic food web, these small planktonic organisms often encounter suction-feeding fish. Studies have identified certain hydrodynamic features that are created by the approach of this visual predator and the generation of its suction flow for capturing food. Similarly, studies have identified certain hydrodynamic features that evoke the evasive response of copepods. This is a review of the copepod sensory motor system as pertains to understanding their response to suction-feeding fish. Analyses of the reaction time, threshold sensitivity, structure of sensors, and evasive behavior by this key prey of fish can be useful for evaluating the effectiveness of feeding tactics in response to suction flow. To illustrate, we present results comparing a copepod from a fishless lake (Hesperodiaptomus shoshone) to a copepod from a rich fishing ground (Calanus finmarchicus). We designed a flow mimic that produces a realistic mushroom-cap-shaped flow field and realistic accelerations of flow; the copepods treated the mimic as a threat and performed jumps directed up and away from the siphon. Calanus finmarchicus responded at an average threshold strain rate of 18.7/s, escaped at 0.46 m/s, and traveled 5.99 mm, most frequently as a single jump. Hesperodiaptomus shoshone responded at a strain rate of 15.1/s that is not significantly different, escaped more slowly at 0.22 m/s and traveled a shorter distance of 3.01 mm using a series of hops. The high variability noted in the initial angle of the body and the maximum change in body angle suggests that unpredictability in the escape maneuver is another aspect of the tactic of copepods. The speed of the escape by small copepods 2-3 mm long is overwhelmed by the speed of the attack by the much larger, faster fish; if the copepod reacts when it is within the fish's arena of capture (<1.5 mm from mouth

  8. 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

  9. Remora fish suction pad attachment is enhanced by spinule friction.

    PubMed

    Beckert, Michael; Flammang, Brooke E; Nadler, Jason H

    2015-11-01

    The remora fishes are capable of adhering to a wide variety of natural and artificial marine substrates using a dorsal suction pad. The pad is made of serial parallel pectinated lamellae, which are homologous to the dorsal fin elements of other fishes. Small tooth-like projections of mineralized tissue from the dorsal pad lamella, known as spinules, are thought to increase the remora's resistance to slippage and thereby enhance friction to maintain attachment to a moving host. In this work, the geometry of the spinules and host topology as determined by micro-computed tomography and confocal microscope data, respectively, are combined in a friction model to estimate the spinule contribution to shear resistance. Model results are validated with natural and artificially created spinules and compared with previous remora pull-off experiments. It was found that spinule geometry plays an essential role in friction enhancement, especially at short spatial wavelengths in the host surface, and that spinule tip geometry is not correlated with lamellar position. Furthermore, comparisons with pull-off experiments suggest that spinules are primarily responsible for friction enhancement on rough host topologies such as shark skin. © 2015. Published by The Company of Biologists Ltd.

  10. The Teleost Intramandibular Joint: A mechanism That Allows Fish to Obtain Prey Unavailable to Suction Feeders.

    PubMed

    Gibb, Alice C; Staab, Katie; Moran, Clinton; Ferry, Lara A

    2015-07-01

    Although the majority of teleost fishes possess a fused lower jaw (or mandible), some lineages have acquired a secondary joint in the lower jaw, termed the intramandibular joint (IMJ). The IMJ is a new module that formed within the already exceptionally complex teleost head, and disarticulation of two bony elements of the mandible potentially creates a "double-jointed" jaw. The apparent independent acquisition of this new functional module in divergent lineages raises a suite of questions. (1) How many teleostean lineages contain IMJ-bearing species? (2) Does the IMJ serve the same purpose in all teleosts? (3) Is the IMJ associated with altered feeding kinematics? (4) Do IMJ-bearing fishes experience trade-offs in other aspects of feeding performance? (5) Is the IMJ used to procure prey that are otherwise unavailable? The IMJ is probably under-reported, but has been documented in at least 10 lineages within the Teleostei. Across diverse IMJ-bearing lineages, this secondary joint in the lower jaw serves a variety of functions, including: generating dynamic out-levers that allow fish to apply additional force to a food item during jaw closing; allowing fish to "pick" individual prey items with pincer-like jaws; and facilitating contact with the substrate by altering the size and orientation of the gape. There are no consistent changes in feeding kinematics in IMJ-bearing species relative to their sister taxa; however, some IMJ-bearing taxa produce very slow movements during the capture of food, which may compromise their ability to move prey into the mouth via suction. Despite diversity in behavior, all IMJ-bearing lineages have the ability to remove foods that are physically attached to the substrate or to bite off pieces from sessile organisms. Because such prey cannot be drawn into the mouth by suction, the IMJ provides a new mechanism that enables fish to obtain food that otherwise would be unavailable. © The Author 2015. Published by Oxford University Press on

  11. Aquatic feeding in pipid frogs: the use of suction for prey capture

    PubMed Central

    Carreño, Carrie A.; Nishikawa, Kiisa C.

    2010-01-01

    Inertial suction feeding is the most common method of prey capture among aquatic vertebrates. However, it had been unclear whether the aquatic frogs in the family Pipidae also used inertial suction for prey capture. In this study, we examined feeding behavior in four species of pipids, Pipa pipa, Xenopus laevis, Hymenochirus boettgeri and Pseudhymenochirus merlini. Pressure in the buccopharyngeal cavity was measured during prey capture. These pressure measurements were coupled with high-speed recordings of feeding behavior. For each species, the internal buccopharyngeal pressure was found to drop significantly below ambient pressure, and changes in pressure corresponded with the onset of mouth opening. Kinematic analysis revealed that all species of pipids generated subambient pressure during prey capture; H. boettgeri and P. merlini relied solely on inertial suction feeding. Pipa pipa and X. laevis additionally employed forelimb scooping during prey capture but both of these species demonstrated the ability to capture prey with inertial suction alone. Based on buccopharyngeal pressure measurements as well as kinematic analyses, we conclude that inertial suction feeding is used during prey capture in these four species of pipids. PMID:20511513

  12. 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

  13. 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

  14. A giant chelonioid turtle from the late Cretaceous of Morocco with a suction feeding apparatus unique among tetrapods.

    PubMed

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

    2013-01-01

    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. 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. 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 Maastrichtian phosphatic beds of Morocco, further

  15. 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. © The Author 2015. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

  16. 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

  17. Nutrition, feeding, and behavior of fish.

    PubMed

    Lall, Santosh P; Tibbetts, Sean M

    2009-05-01

    Nutrition and feeding influence growth, reproduction, and health of fish and their response to physiologic and environmental stressors and pathogens. The basics of fish metabolism are similar to those of warm-blooded animals in that they involve food intake, digestion, absorption, and transport of nutrients to the various tissues. Fish, however, being the most primitive form of vertebrates, possess some distinguishing features which will be discussed. Unlike warm-blooded animals, which are homoeothermic, fish are poikilothermic, so their body temperature and metabolic rate depends on the water temperature and this has practical implications for the nutrition, feeding and health of fish. Several behavioral responses have been linked to methods of feeding, feeding habits, frequency of feeding, mechanisms of food detection, and food preferences. Fish are also unique among vertebrates in their ability to absorb minerals not only from their diets but also from water through their gills and skin.

  18. 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.

  19. Spatial and temporal patterns of water flow generated by suction-feeding bluegill sunfish Lepomis macrochirus resolved by Particle Image Velocimetry.

    PubMed

    Day, Steven W; Higham, Timothy E; Cheer, Angela Y; Wainwright, Peter C

    2005-07-01

    The suction-feeding fish generates a flow field external to its head in order to draw prey into the mouth. To date there are very few empirical measurements that characterize the fluid mechanics of suction feeding, particularly the temporal and spatial patterns of water velocity in front of the fish. To characterize the flow in front of suction-feeding bluegill sunfish Lepomis macrochirus, measurements with high spatial (<1 mm) and temporal (500 Hz) resolution were taken using Particle Image Velocimetry (PIV). In an analysis separate from the PIV, high-speed video sequences were used for a novel method of visually tracking every seed particle for the duration of each feeding in order to determine directly the total parcel of water that the fish ingests. PIV measurements and particle tracking show that water is drawn from all around the mouth. Fluid velocity decreases rapidly with distance from the mouth and is only significant (>5% of speed at the mouth) within roughly 1 mouth diameter of the fish. Suction feeders gain little in terms of extending this flow field by even substantial increases in the fluid speed at the mouth opening. Instead, the chief advantage of increased flow speed at the mouth may be the increased magnitude of generated forces within the space very close to the mouth. After scaling of the velocity field based on size of the mouth opening and the measured fluid speed at a fixed position, the measured velocity profiles for all feedings are very similar to one another, so that a functional relationship for the magnitude of fluid speed as a function of distance from the predator mouth is presented and shown to be accurate over the range of kinematic variables tested. This relationship describes the velocity field both along the centerline of the fish and along transects lying at an angle to the centerline within both the mid-sagittal and frontal planes. Comparison of the time-resolved fluid velocity measurements to gape kinematics demonstrate that

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

    PubMed

    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.

  1. 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.

  2. Electromyographic analysis of masseter muscle in newborns during suction in breast, bottle or cup feeding

    PubMed Central

    2014-01-01

    Background When breastfeeding is difficult or impossible during the neonatal period, an analysis of muscle activity can help determine the best method for substituting it to promote the child’s development. The aim of this study was to analyze the electrical activity of the masseter muscle using surface electromyography during suction in term newborns by comparing breastfeeding, bottle and cup feeding. Methods An observational, cross-sectional analytical study was carried out on healthy, clinically stable term infants, assigned to receive either breast, or bottle or cup feeding. Setting was a Baby Friendly accredited hospital. Muscle activity was analyzed when each infant showed interest in sucking using surface electromyography. Root mean square averages (RMS) recorded in microvolts were transformed into percentages (normalization) of the reference value. The three groups were compared by ANOVA; the “stepwise” method of the multiple linear regression analysis tested the model which best defined the activity of the masseter muscle in the sample at a significance level of 5%. Results Participants were 81 full term newborns (27 per group), from 2 to 28 days of life. RMS values were lower for bottle (mean 44.2%, SD 14.1) than breast feeding (mean 58.3%, SD 12.7) (P = 0.003, ANOVA); cup feeding (52.5%, SD 18.2%) was not significantly different (P > 0.05). For every gram of weight increase, RMS increased by 0.010 units. Conclusions Masseter activity was significantly higher in breastfed newborns than in bottle-fed newborns, who presented the lowest RMS values. Levels of masseter activity during cup-feeding were between those of breast and bottle feeding, and did not significantly differ from either group. This study in healthy full term neonates endorses cup rather than bottle feeding as a temporary substitute for breastfeeding. PMID:24885762

  3. Feeding Practices and Fish Health

    USDA-ARS?s Scientific Manuscript database

    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. Discordance between morphological and mechanical diversity in the feeding mechanism of centrarchid fishes.

    PubMed

    Collar, David C; Wainwright, Peter C

    2006-12-01

    Morphological diversity is routinely used to infer ecological variation among species because differences in form underlie variation in functional performance of ecological tasks like capturing prey, avoiding predators, or defending territories. However, many functions have complex morphological bases that can weaken associations between morphological and functional diversification. We investigate the link between these levels of diversity in a mechanically explicit model of fish suction-feeding performance, where the map of head morphology to feeding mechanics is many-to-one: multiple, alternative forms can produce the same mechanical property. We show that many-to-one mapping leads to discordance between morphological and mechanical diversity in the freshwater fish family, the Centrarchidae, despite close associations between morphological changes and their mechanical effects. We find that each of the model's five morphological variables underlies evolution of suction capacity. Yet, the major centrarchid clades exhibit an order of magnitude range in diversity of suction mechanics in the absence of any clear difference in diversity of the morphological variables. This cryptic pattern of mechanical diversity suggests an evolutionary history for suction performance that is unlike the one inferred from comparisons of morphological diversity. Because many-to-one mapping is likely to be common in functional systems, this property of design may lead to widespread discordance between functional and morphological diversity. Although we focus on the interaction between morphology and mechanics, many-to-one mapping can decouple diversity between levels of organization in any hierarchical system.

  5. Interspecific variation in sternohyoideus muscle morphology in clariid catfishes: functional implications for suction feeding.

    PubMed

    Van Wassenbergh, Sam; Herrel, Anthony; Adriaens, Dominique; Aerts, Peter

    2007-03-01

    Depression of the hyoid apparatus plays a crucial role in generating suction, especially in fishes with a dorso-ventrally flattened head shape. It is generally assumed that shortening of the sternohyoideus muscle, which connects the hyoid to the pectoral girdle, contributes to hyoid depression. However, a recent study on the clariid catfish Clarias gariepinus has shown that this muscle does not shorten but elongates during this phase through retraction of the pectoral girdle. Here, we test whether this pattern is general among clariid catfish, or if variation in the morphology of the sternohyoideus may result in a different sternohyoideus behavior during hyoid depression. First, sternohyoideus mass, effective cross-sectional area, fiber length and fiber diameter were measured and compared for four clariid species. Next, velocity and magnitude of hyoid depression during prey capture (from high-speed videos), as well as patterns of sternohyoideus strain were analyzed (from high-speed X-ray videos) in these species. While morphology and hyoid depression performance varied considerably among these species, only the species with the most massive sternohyoideus, Gymnallabes typus, showed shortening of the sternohyoideus muscle during the initial part of the expansive phase. The data for Channallabes apus demonstrate that increasing the magnitude of hyoid depression does not necessarily require a shortening of the m. sternohyoideus, as it shows elongation of this muscle during hyoid depression. 2007 Wiley-Liss, Inc.

  6. 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

  7. 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.

  8. Persistent halogenated hydrocarbons in fish feeds manufactured in South China.

    PubMed

    Guo, Ying; Yu, Huan-Yun; Zhang, Bao-Zhong; Zeng, Eddy Y

    2009-05-13

    Persistent halogenated hydrocarbons (PHHs), including organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs), in fish feeds (including trash fish and compound feed) manufactured in South China, were analyzed. PHHs were ubiquitous in fish feeds, with the concentrations of OCPs, PBDEs, and PCBs at the upper, mid, and lower levels of the global range. Trash fish generally contained higher concentrations of DDXs (sum of o,p'- and p,p'-DDT, -DDD, and -DDE and p,p'-DDMU), especially p,p'-DDT and low-brominated PBDEs, while compound feeds had higher concentrations of highly brominated BDEs, e.g., BDE-209. In addition, no concentration difference of HCHs and PCBs was found between trash fish and compound feeds. The habit of direct use of trash fish as fish feeds has induced the accumulation of DDXs in aquatic species in China, and trash fish collected in South China seemed to be slightly hazardous to wildlife because of the concentrations of DDXs. The results from the present study suggest that the use pattern of fish feeds in China may have to be adjusted to minimize contamination of fishery products and wildlife by PHHs. Use of compound feeds produced with controlled procedures should be encouraged, whereas that of trash fish should be restricted, at least for now.

  9. 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.

  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

    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

    2016-03-10

    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.

  12. 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

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

    NASA Astrophysics Data System (ADS)

    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

    2016-03-01

    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.

  14. 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.

  15. 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. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  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. Unexpectedly high mercury level in pelleted commercial fish feed

    SciTech Connect

    Choi, M.H.; Cech, J.J. Jr.

    1998-10-01

    An unexpectedly high mercury (Hg) level was found in a pelleted commercial fish feed used to feed fish in laboratory and fish farm settings. Mean total Hg (T-Hg) concentration in the commercial fish pellets was 66 ppb. Mean total selenium (T-Se) concentration in the pellets was 1,120 ppb (ranging from 790 to 1,360 ppb). Total Hg and Se in the whole blood of Sacramento blackfish and in the fish feed were determined by inductively coupled plasma-mass spectrometry (ICP-MS). During a 10-week sampling period T-Hg in blood fluctuated between 35 and 56 ppb. A highly significant, positive correlation was found between T-Hg in the fish blood and in the fish feed through the sampling period. On the other hand, no correlation was found between T-Se in the fish feed and T-Hg or T-Se blood level. Researchers working with fish in Hg studies need to know that fish pellets may contain Hg and to consider the influence of these pellets in their results.

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

    PubMed Central

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

    2009-01-01

    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. PMID:19324657

  19. Effluent profile of commercially used low-phosphorus fish feeds.

    PubMed

    Sugiura, Shozo H; Marchant, Daniel D; Kelsey, Kevin; Wiggins, Thomas; Ferraris, Ronaldo P

    2006-03-01

    Excess phosphorus (P) in aquaculture feeds contributes to the eutrophication of natural waters. While commercially available low-P (LP) fish feeds have been developed, there is uncertainty about their potential to reduce effluent P while maintaining fish growth relative to regular P (RP) feeds. We therefore simulated commercial aquaculture conditions and fed for 55 days rainbow trout (approximately 190 kg/raceway, n = 3 raceways/diet) RP (1.4% total P) and LP (1.0%) feeds then determined effluent P levels, fish growth, and feed costs. Excretions of fecal-P and soluble-P, but not particulate-P, in effluents were greater in RP than in LP ponds. Fish growth, bone-P and plasma-P were similar between diets, demonstrating that LP feeds can lower effluent P levels without compromising growth. Costs were 0.97 dollars/kg fish production for LP feeds, and 0.74 dollars/kg for RP. Because feed is the largest variable cost in commercial aquaculture, the use of LP feeds can significantly increase production costs.

  20. 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

  1. 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.

  2. Unexpectedly high mercury concentration in commercial fish feed

    SciTech Connect

    Choi, H.; Cech, J. Jr.

    1995-12-31

    Unexpectedly high mercury was found in a commercial fish pellet which has been widely used to feed fish in laboratory and fish farm settings. Researchers working with fish in mercury studies need to know that fish pellets contain mercury and consider the pellets, influence in their results. Mean mercury concentration in the commercial fish pellet was 47.4 ug/g (ranging from 35 to 56 ug Hg/g). Total mercury (T-Hg) in the blood of Sacramento blackfish (orthodon microlepidotus), fed the commercial feed for 8 months, was determined by inductively coupled plasma-mass spectrometry (ICP-MS). Mean blood T-Hg reached a steady state at 41 ug Hg/L (ranging from 34 to 51 ug Hg/L) during 5 months of feeding after capture from Clear Lake in California. The accumulation of mercury in blood followed a monoexponential pattern, in accordance with a one-compartment model. There were great variations in mercury levels in blood between individual fishes. The mercury concentrations in the blood did not tend to increase with the growth of the fish. In summary, feed sources of mercury need to be considered in mercury exposure experiments.

  3. Recycle food wastes into high quality fish feeds for safe and quality fish production.

    PubMed

    Wong, Ming-Hung; Mo, Wing-Yin; Choi, Wai-Ming; Cheng, Zhang; Man, Yu-Bon

    2016-12-01

    The amount of food waste generated from modern societies is increasing, which has imposed a tremendous pressure on its treatment and disposal. Food waste should be treated as a valuable resource rather than waste, and turning it into fish feeds would be a viable alternative. This paper attempts to review the feasibility of using food waste to formulate feed pellets to culture a few freshwater fish species, such as grass carp, grey mullet, and tilapia, under polyculture mode (growing different species in the same pond). These species occupy different ecological niches, with different feeding modes (i.e., herbivorous, filter feeding, etc.), and therefore all the nutrients derived from the food waste could be efficiently recycled within the ecosystem. The problems facing environmental pollution and fish contamination; the past and present situation of inland fish culture (focusing on South China); upgrade of food waste based feed pellets by adding enzymes, vitamin-mineral premix, probiotics (yeast), prebiotics, and Chinese medicinal herbs into feeds; and potential health risks of fish cultivated by food waste based pellets are discussed, citing some local examples. It can be concluded that appropriate portions of different types of food waste could satisfy basic nutritional requirements of lower trophic level fish species such as grass carp and tilapia. Upgrading the fish pellets by adding different supplements mentioned above could further elevated the quality of feeds, leading to higher growth rates, and enhanced immunity of fish. Health risk assessments based on the major environmental contaminants (mercury, PAHs and DDTs) in fish flesh showed that fish fed food waste based pellets are safer for consumption, when compared with those fed commercial feed pellets. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. [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%.

  5. 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. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. Investigation into feed preparation for regulatory fish metabolism studies.

    PubMed

    Goeritz, Ina; Atorf, Cornelia; Whalley, Paul; Seymour, Paul; Klein, Michael; Schlechtriem, Christian

    2014-02-01

    Test diets used in fish metabolism studies for regulatory purposes must be homogenously fortified with the radiolabelled test substance and stable with respect to leaching. Standard fish food, as used in commercial fish farming, should also be used in fish metabolism studies. Therefore, suitable spiking and coating procedures are required to ensure the correct dosing of the fish during the experiment. Methods for the homogeneous, safe and efficient application of radiolabelled test items to the surface of commercial feeding pellets were developed. Leaching studies showed that test items of low lipophilicity applied to feeding pellets need to be stabilised, to reduce the risk of significant losses prior to ingestion by the fish. Coating of solvent-spiked pellets with calcium alginate was shown to reduce leaching losses of water-soluble test items significantly. Alternatively, commercial feeding pellets can be coated with alginate or vegetable oil fortified with a radiolabelled test item also leading to sufficiently stabilised test diets. Experimental conditions, such as the water temperature, may have a significant effect on the leaching behaviour of the test items. A detailed description of different spiking and coating procedures for the preparation of experimental diets suitable for fish metabolism studies is provided. © 2013 Society of Chemical Industry.

  7. Gastric suction

    MedlinePlus

    Gastric lavage; Stomach pumping; Nasogastric tube suction; Bowel obstruction - suction ... A tube is inserted through your nose or mouth, down the food pipe (esophagus), and into the stomach. Your ...

  8. A survey of chemical constituents in National Fish Hatchery fish feed

    USGS Publications Warehouse

    Maule, Alec G.; Gannam, Ann; Davis, Jay

    2006-01-01

    Recent studies have demonstrated that various fish feeds contain significant concentrations of contaminants, many of which can bioaccumulate and bioconcentrate in fish. It appears that numerous 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 presence and concentration of contaminants in feeds used in National Fish Hatcheries managed by the U.S. Fish & Wildlife Service, we systematically collected samples of feed from 11 hatcheries that raise cold-water species, and analyzed them for a suite of chemical contaminants. All of the samples (collected from October 2001 to October 2003) contained measurable concentrations of at least one dioxin, furan, polychlorinated biphenyl (PCB) congener, or dichlorodiphenyltrichloroethane (DDT) metabolite. All samples which were assayed for all contaminants contained one or more of those classes of compounds and most contained more than one; dioxin was detected in 39 of the 55 samples for which it was assayed, 24 of 55 contained furans and 24 of 55 samples contained DDT or its metabolites. There with 10- to 150-fold differences in the range in concentrations of the additive totals for PCBs, dioxins, furans and DDT. Although PCBs were the most commonly detected contaminant in our study (all samples in which it was assayed), the concentrations (range: 0.07 to 10.46 ng g·1 wet weight) were low compared to those reported previously. In general, we also found lower levels of organochlorine contaminants than have been reported previously in fish feed. Perhaps most notable is the near absence of OC pesticides~xcept for DDT (and its metabolites) and just two samples containing benzene hexachloride (Lindane). While contaminant concentrations were generally low, the ecological impacts can not be determined without a measure of the bioaccumulation of these compounds in the

  9. Comparative feeding ecology of abyssal and hadal fishes through stomach content and amino acid isotope analysis

    NASA Astrophysics Data System (ADS)

    Gerringer, M. E.; Popp, B. N.; Linley, T. D.; Jamieson, A. J.; Drazen, J. C.

    2017-03-01

    The snailfishes, family Liparidae (Scorpaeniformes), have found notable success in the hadal zone from 6000-8200 m, comprising the dominant ichthyofauna in at least five trenches worldwide. Little is known about the biology of these deepest-living fishes, nor the factors that drive their success at hadal depths. Using recent collections from the Mariana Trench, Kermadec Trench, and neighboring abyssal plains, this study investigates the potential role of trophic ecology in structuring fish communities at the abyssal-hadal boundary. Stomach contents were analyzed from two species of hadal snailfishes, Notoliparis kermadecensis and a newly-discovered species from the Mariana Trench. Amphipods comprised the majority (Kermadec: 95.2%, Mariana: 97.4% index of relative importance) of stomach contents in both species. Decapod crustaceans, polychaetes (N. kermadecensis only), and remains of carrion (squid and fish) were minor dietary components. Diet analyses of abyssal species (families Macrouridae, Ophidiidae, Zoarcidae) collected from near the trenches and the literature are compared to those of the hadal liparids. Stomachs from abyssal fishes also contained amphipods, however macrourids had a higher trophic plasticity with a greater diversity of prey items, including larger proportions of carrion and fish remains; supporting previous findings. Suction-feeding predatory fishes like hadal liparids may find an advantage to descending into the trench - where amphipods are abundant. More generalist feeders and scavengers relying on carrion, such as macrourids, might not benefit from this nutritional advantage at hadal depths. Compound specific isotope analysis of amino acids was used to estimate trophic level of these species (5.3±0.2 Coryphaenoides armatus, 5.2±0.2 C. yaquinae, 4.6±0.2 Spectrunculus grandis, 4.2±0.2 N. kermadecensis, 4.4±0.2 Mariana snailfish). Source amino acid δ15N values were especially high in hadal liparids (8.0±0.3‰ Kermadec, 6.7±0.2

  10. Determination of emamectin benzoate in medicated fish feed.

    PubMed

    Farer, L J; Hayes, J; Rosen, J; Knight, P

    1999-01-01

    A method was developed to quantitate emamectin benzoate in fish feed at levels between 5 and 15 ppm. The active ingredient is extracted from 20 g medicated feed into aqueous-methanolic solvent by overnight shaking. A solid-phase extraction procedure using a 2 g C18 cartridge is then used to concentrate the active residue and remove interfering matrix components. The extracted drug and internal standard are eluted from the cartridge, evaporated to dryness, and reconstituted in methanol. A control feed sample and fortified control working standard are simultaneously prepared. Remaining interferences and sample analysis are further separated on a gradient liquid chromatographic system. Recovery of emamectin benzoate from fortified feeds ranged from 97 to 100%, with a coefficient of variation (CV) of 1.2%. Determination of emamectin benzoate in medicated feeds resulted in CVs ranging from 2.3 to 4.2% and recoveries of 88 to 98% of label claim.

  11. Microscopic recognition and identification of fish meal in compound feeds.

    PubMed

    van Raamsdonk, L W D; Prins, T W; van de Rhee, N; Vliege, J J M; Pinckaers, V G Z

    2017-08-01

    Fish meal is an accepted ingredient in compound feed. Unauthorised application is primarily enforced by visual inspection, i.e., microscopy. In order to document the visually available diversity, fragments of bones and scales of 17 teleost fish species belonging to seven different orders were investigated for their diversity in the presence of structural elements: lacunae and canaliculae in bone fragments and type of growth rings and teeth of scale fragments. Despite the classical division into cellular bones and acellular bones of teleost fish, i.e., whether or not possessing osteocytes, the current examinations revealed patterns of lacunae, in some types accompanied with canaliculae, in all 17 species investigated. In total seven types of bone structures were defined, and six types of scale structures. Profiles with the relative frequency of each bone type per species were established. The share of acellular bone fragments appeared to be related to the evolutionary position of the species. Results of proficiency tests for the detection of fish meal reveal that in most cases the sensitivity and specificity for the detection of fish meal ranges from sufficient to perfect. Only some specified circumstances can hamper proper recognition and identification, most notably salmon bone fragments mimicking bone fragments from terrestrial animals, and pieces of hydrolysed proteins or minerals mimicking acellular fish bone fragments. The expertise gained in this study would help to improve the distinction between fish meal and terrestrial animal material in compound feed, and it supports the application of the species-to-species ban with respect to the valorisation of by-products from fish farms in aquafeed. In a broader perspective, the current expertise might be helpful to detect fraud throughout the feed/food production chain. The matrix of characteristics versus species is implemented in a data model running in the expert system 'Determinator' for facilitating

  12. [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.

  13. 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

  14. 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. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  15. 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.

  16. Biorobotic adhesion in water using suction cups.

    PubMed

    Bandyopadhyay, Promode R; Hrubes, J Dana; Leinhos, Henry A

    2008-03-01

    Echeneid fish, limpets and octopi use suction cups for underwater adhesion. When echeneid fish use suckers to 'hitch a ride' on sharks (which have riblet-patterned skins), the apparent absence of any pump or plumbing may be an advantage over biorobotic suction cups. An intriguing question is: How do they achieve seemingly persistent leak-free contact at low energy cost over rough surfaces? The design features of their suckers are explored in a biorobotic context of adhesion in water over rough surfaces. We have carried out experiments to compare the release force and tenacity of man-made suction cups with those reported for limpets and echeneid fish. Applied tensile and shear release forces were monotonically increased until release. The effects of cup size and type, host surface roughness, curvature and liquid surface tension have been examined. The flow of water in the sharkskin-like host surface roughness has been characterized. The average tenacity is 5.28 N cm(-2) (sigma = 0.53 N cm(-2), N = 37) in the sub-ambient pressure range of 14.6-49.0 kPa, in man-made cups for monotonically increasing applied release force. The tenacity is lower for harmonically oscillating release forces. The dynamic structural interactions between the suction cup and the oscillating applied forcing are discussed. Inspired by the matching of sharkskin riblet topology in echeneid fish suckers, it was found that biorobotic sealed contact over rough surfaces is also feasible when the suction cup makes a negative copy of the rough host surface. However, for protracted, persistent contact, the negative topology would have to be maintained by active means. Energy has to be spent to maintain the negative host roughness topology to minute detail, and protracted hitch-riding on sharks for feeding may not be free for echeneid fish. Further work is needed on the mechanism and efficiency of the densely populated tiny actuators in the fish suckers that maintain leak-proof contact with minimal

  17. The utilization of crude fish oil (CFO) to increase mudcrab (Scylla serrata) feed quality

    NASA Astrophysics Data System (ADS)

    Lamid, Mirni; Agustono

    2017-02-01

    Crude fish oil is one of essential fatty acid sources, which is found in Sardinella lemuru. This research aims to study the quality improvement of mudcrab(Scylla serrata) feed. Four feed formulations were designed by using completely randomized design, including P0 = trash fish + 1% tapioca starch; P1=trash fish + 2.0% crude fish oil + 1% tapioca starch;, P2= trash fish +4.0% crude fish oil + 1% tapioca starch; P3=trash fish + 6.0% crude fish oil + 1% tapioca starch; P4=trash fish +8.0% crude fish oil + 1% tapioca starch, respectively, which were carried out in quadruplicate. This study showed that feed formulation significantly affected crude protein, crude fiber, crude lipid, ash, organic matter and nitrogen free extract and energy of mudcrab. The P2 feed was the best formulation but had a slight different from P3 formulation.

  18. 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.

  19. 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

  20. Carryover of aflatoxins from feed to lambari fish (Astyanax altiparanae) tissues.

    PubMed

    Michelin, E C; Massocco, M M; Godoy, S H S; Baldin, J C; Yasui, G S; Lima, C G; Rottinghaus, G E; Sousa, R L M; Fernandes, A M

    2017-02-01

    The aim of this study was to verify the carryover of aflatoxin B1 from feed to lambari fish. Aflatoxins (AF) were incorporated into feed, checking the levels by HPLC. Treatments were: Control, feed without toxin; A, feed + 10 µg AFB1 kg(-)(1); B, feed + 20 µg AFB1 kg(-)(1); and C, feed + 50 µg AFB1 kg(-)(1). Juveniles of lambari fish were placed in 12 aquariums at a density of 50 fish/m(2). Fish were fed twice a day with extruded feed, at 5% of animal biomass. The unit sample was constituted by a pool of 10 fish. AFs B1, B2, G1, G2 and M1 were quantified by HPLC in fish muscle and liver after 30, 60, 90 and 120 days of experiment. There was accumulation of AFs is fish liver and muscle, mainly after 90 days. Fish from treatment C had higher levels of AFB1 in muscle when compared with the others, and AFB1 in muscle at 120 days was similar to the levels in feed. Therefore, when lambari fish is exposed on a daily and long-term basis to AFs in feed, the regulation limits for AFs in animal feed do not guarantee safety for consumers.

  1. 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. © 2010 Wiley-Liss, Inc.

  2. Integrated diversification of locomotion and feeding in labrid fishes.

    PubMed

    Collar, David C; Wainwright, Peter C; Alfaro, Michael E

    2008-02-23

    An organism's performance of any ecological task involves coordination of multiple functional systems. Feeding performance is influenced by locomotor abilities which are used during search and capture of prey, as well as cranial mechanics, which affect prey capture and processing. But, does this integration of functional systems manifest itself during evolution? We asked whether the locomotor and feeding systems evolved in association in one of the most prominent and diverse reef fish radiations, the Labridae. We examined features of the pectoral fins that affect swimming performance and aspects of the skull that describe force and motion of the jaws. We applied a recent phylogeny, calculated independent contrasts for 60 nodes and performed principal components analyses separately on contrasts for fin and skull traits. The major axes of fin and skull diversification are highly correlated; modifications of the skull to amplify the speed of jaw movements are correlated with changes in the pectoral fins that increase swimming speed, and increases in force capacity of the skull are associated with changes towards fins that produce high thrust at slow speeds. These results indicate that the labrid radiation involved a strong connection between locomotion and feeding abilities.

  3. 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.

  4. Toxicity of melamine, an adulterant in fish feeds: experimental assessment of its effects on tilapia.

    PubMed

    Phromkunthong, W; Nuntapong, N; Boonyaratpalin, M; Kiron, V

    2013-06-01

    Unscrupulous inclusion of melamine in fish feeds can be harmful to fish and may be hazardous to human health. An eight-week feeding trial examined the effects of melamine (inclusion levels; 5-30 g kg⁻¹ feed) on the growth performance, feed efficiency, histopathological changes and melamine residues in sex-reversed red tilapia, Oreochromis niloticus (L.) × O.mossambicus (Peters). Fish which received melamine-containing feeds grew less, utilized feeds less efficiently and performed poorly, besides exhibiting defects such as fin erosion, anorexia, sluggish swimming behaviour, paling/darkening of skin and low survival. Melamine concentration in the fish reflected its inclusion level in the feeds, and the content was higher in the viscera than in the fish fillet or whole fish. Histopathological alterations were evident in the kidney, liver and gills of fish subjected to melamine treatment - the severity of lesions corresponded to its dosage. Enlargement of renal tubules was observed in the kidney of fish fed with ≥10 g melamine kg⁻¹ feed, although, crystals were not deposited. Fish subjected to melamine insult had more prominent lesions in liver than in kidney. Toxic effects on the gills manifested as epithelial hyperplasia of the primary and secondary lamellae. The anomalies were severe at higher intake levels of melamine. © 2012 Blackwell Publishing Ltd.

  5. 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.

  6. Comparative study on gastrointestinal microbiota of eight fish species with different feeding habits.

    PubMed

    Li, J; Ni, J; Li, J; Wang, C; Li, X; Wu, S; Zhang, T; Yu, Y; Yan, Q

    2014-12-01

    To reveal the effects of fish genotype, feeding habits and serum physiological index on the composition of gastrointestinal microbiota, eight fish species with four different feeding habits were investigated. The V1 to V3 regions of 16S rRNA gene were analysed by high-throughput sequencing (454 platform) to compare the gut microbiota of different fish species. A total of 551 995 high-quality sequences with an average length of 463 bp were obtained from the 48 samples. No significant difference was observed among the detected sequences obtained from fishes with different feeding habits (One-way anova, F = 1·003, P = 0·400), but the number of OTUs among different feeding habits was significantly different (One-way anova, F = 7·564, P < 0·001). Additionally, significant correlations were detected between the fish genotype and microbial composition (partial Mantel test, all P values = 0·001) in the stomach, foregut and hindgut. Moreover, different core intestinal microbiota was also noticed in the eight fish species with different feeding habits. Feeding habits and genotype clearly affected the gastrointestinal microbiota of fish. Moreover, the evolutionary process shaped the serum physiological indexes of fish. This study provided much important information for developing commercial fish feeds. © 2014 The Society for Applied Microbiology.

  7. 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).

  8. 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.

  9. 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.

  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. 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.

  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.

  13. Developmental intervals during the larval and juvenile stages of the Antarctic myctophid fish Electrona antarctica in relation to changes in feeding and swimming functions

    NASA Astrophysics Data System (ADS)

    Moteki, Masato; Tsujimura, Eri; Hulley, Percy-Alexander

    2017-06-01

    The Antarctic myctophid fish species Electrona antarctica is believed to play a key role in the Southern Ocean food web, but there have been few studies on its early life history. This study examined the developmental changes in the external morphology and osteology of E. antarctica from the early larva to juvenile stages through the transformation phase and inferred changes in its behaviour and feeding mode. Once the larvae reached 12-13 mm body length (BL), they adopted a primordial suction feeding mode along with the acquisition of early swimming capabilities. Thereafter, both swimming and feeding functions were enhanced through fin development and ossification and acquisition of elements of the jaw and suspensorium. These processes indicate that larvae transition from the planktonic to nektonic phase upon reaching 12-13 mm BL when they enhance their both swimming and feeding abilities with growth. Transformation occurred when larvae reached 19-21 mm BL with changes such as discontinuous increases in eye diameter and upper jaw length and the appearance of photophores and dense body pigmentation. Osteological development of swimming- and feeding-related structures were mostly complete after transformation. Rapid changes in external morphology and osteology during the transformation stage are most likely related to ontogenetic vertical migration into deep waters.

  14. Red Light Stimulates Feeding Motivation in Fish but Does Not Improve Growth

    PubMed Central

    Bovi, Thais S.; de Freitas, Renato H. A.; da Silva, Danielle F.; Delicio, Helton C.; Barreto, Rodrigo Egydio

    2013-01-01

    Nile tilapia fish were individually reared under similar light levels for 8 weeks under five colored light spectra (maximum wavelength absorbance): white (full light spectrum), blue (∼452 nm), green (∼516 nm), yellow (∼520 nm) or red (∼628 nm). The effects of light on feeding, latency to begin feeding, growth and feed conversion were measured during the last 4 weeks of the study (i.e., after acclimation). We found that red light stimulates feeding, as in humans, most likely by affecting central control centers, but the extra feeding is not converted into growth. PMID:23516606

  15. Particulate waste outflow from fish-farming cages. How much is uneaten feed?

    PubMed

    Ballester-Moltó, M; Sanchez-Jerez, P; Cerezo-Valverde, J; Aguado-Giménez, F

    2017-06-15

    Particulate wastes drive benthic organic enrichment from cage fish farming. Differentiation between faeces and uneaten feed estimates at cage level are of great value to both economize the feeding process and reduce waste. This study estimates the particulate waste outflowing cages at different depths and orientations, and the wasted feed component by combining in situ measurements and modelling. Particulate matter flux (PMF) was greater vertically through the cage bottoms (60.89%), but lateral outflow was also substantial (39.11%). PMF occurs all around the cages, and the influence of the mainstream current was low. Wasted feed was greatly variable, reaching high values (about 50% of supplied feed. The self-application of feed wastage monitoring and estimates by fish farmers is recommended to improve sustainability. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Fatty acid composition of fish species with different feeding habits from an Arctic Lake.

    PubMed

    Gladyshev, M I; Sushchik, N N; Glushchenko, L A; Zadelenov, V A; Rudchenko, A E; Dgebuadze, Y Y

    2017-05-01

    We compared the composition and content of fatty acids (FAs) in fish with different feeding habits (sardine (least) cisco Coregonus sardinella, goggle-eyed charr (pucheglazka) form of Salvelinus alpinus complex, humpback whitefish Coregonus pidschian, broad whitefish Coregonus nasus, boganid charr Salvelinus boganidae, and northern pike Esox lucius from an Arctic Lake. Feeding habits of the studied fish (planktivore, benthivore, or piscivore) significantly affected the composition of biomarker fatty acids and the ratio of stable isotopes of carbon and nitrogen in their biomass. The hypothesis on a higher content of eicosapentaenoic and docosahexaenoic acids in the fish of higher trophic level (piscivores) when compared within the same taxonomic group (order Salmoniformes) was confirmed.

  17. Dining in the Deep: The Feeding Ecology of Deep-Sea Fishes

    NASA Astrophysics Data System (ADS)

    Drazen, Jeffrey C.; Sutton, Tracey T.

    2017-01-01

    Deep-sea fishes inhabit ˜75% of the biosphere and are a critical part of deep-sea food webs. Diet analysis and more recent trophic biomarker approaches, such as stable isotopes and fatty-acid profiles, have enabled the description of feeding guilds and an increased recognition of the vertical connectivity in food webs in a whole-water-column sense, including benthic-pelagic coupling. Ecosystem modeling requires data on feeding rates; the available estimates indicate that deep-sea fishes have lower per-individual feeding rates than coastal and epipelagic fishes, but the overall predation impact may be high. A limited number of studies have measured the vertical flux of carbon by mesopelagic fishes, which appears to be substantial. Anthropogenic activities are altering deep-sea ecosystems and their services, which are mediated by trophic interactions. We also summarize outstanding data gaps.

  18. Dining in the Deep: The Feeding Ecology of Deep-Sea Fishes.

    PubMed

    Drazen, Jeffrey C; Sutton, Tracey T

    2017-01-03

    Deep-sea fishes inhabit ∼75% of the biosphere and are a critical part of deep-sea food webs. Diet analysis and more recent trophic biomarker approaches, such as stable isotopes and fatty-acid profiles, have enabled the description of feeding guilds and an increased recognition of the vertical connectivity in food webs in a whole-water-column sense, including benthic-pelagic coupling. Ecosystem modeling requires data on feeding rates; the available estimates indicate that deep-sea fishes have lower per-individual feeding rates than coastal and epipelagic fishes, but the overall predation impact may be high. A limited number of studies have measured the vertical flux of carbon by mesopelagic fishes, which appears to be substantial. Anthropogenic activities are altering deep-sea ecosystems and their services, which are mediated by trophic interactions. We also summarize outstanding data gaps.

  19. Survey of estrogenic activity in fish feed by yeast estrogen-screen assay.

    PubMed

    Matsumoto, Takeru; Kobayashi, Makito; Moriwaki, Toshihisa; Kawai, Shin'ichiro; Watabe, Shugo

    2004-10-01

    Fishes have been used as laboratory animal for research of estrogenic endocrine disrupters by many researchers. However, much less attention was paid to the possibility that compounds with estrogenic activity are present in fish diets. In order to examine this possibility, we measured the estrogenic activity in commercial fish feed by in vitro yeast estrogen-screen (YES) assay based on the binding ability of tested compounds to estrogen receptors. Estrogenic activity was detected in all the commercial fish feed examined (0.2-6.2 ng estradiol equivalent/g fish feed), some phytoestrogens (genistein, formononetin, equol and coumestrol; relative activity to estradiol, 8.6 x 10(-6)-1.1 x 10(-4) by giving a value of 1.0 to estradiol) and some androgens (testosterone, 11-ketotestosterone and 5 alpha-dihydrotestosterone; relative activity to estradiol, 3.0 x 10(-6)-1.2 x 10(-4)). Therefore, it is possible that these compounds could affect the results of in vivo estrogen assay, such as vitellogenin production in male fish, especially when fish are fed commercial feed.

  20. Seasonal variation of assemblage and feeding guild structure of fish species in a boreal tidal basin

    NASA Astrophysics Data System (ADS)

    Kellnreitner, Florian; Pockberger, Moritz; Asmus, Harald

    2012-08-01

    Species composition, abundance, feeding relationships and guild structure of the fish assemblage in the Sylt-Rømø bight, a tidal basin in the northern Wadden Sea, were investigated to show seasonal differences and the importance of functional groups in this area. The tidal flats and in shallow subtidal areas were sampled using a beach seine and a bottom trawl net was used for deeper subtidal areas and tidal gullies. Species richness of fish was highest in summer where 26 species were caught, while the lowest richness was recorded in winter (17 species). Clear differences in species richness and abundance were found between shallow areas and deeper parts of the bight. Clupea harengus and Ammodytes tobianus were the most abundant species in deeper areas, while Pomatoschistus microps and Pomatoschistus minutus dominated shallower waters. Gut contents of 27 fish species were identified and the guild structure analyzed by UPGMA clustering of niche overlaps. Calanoid copepods (19.9%), Crangon crangon (18.2%) and mysid shrimps (8.4%) were the most abundant prey items of all fish species combined. Seven feeding guilds were present in the fall and winter, and eight and six in spring and summer, respectively. Fish feeding on calanoid copepods and C. crangon were present year round, whereas the occurrence of other guilds varied between seasons. Species composition of prey changed through seasons and, for some fish species, even the feeding mode itself varied with season. Most noticeable, 11 fish species changed guilds between seasons. We found a convergence in summer towards abundant prey items, whereas in winter diet overlap was lower. This is the first investigation of guild structure of almost all fish species present in a Wadden Sea area, and shows that consideration of seasonal differences is essential when determining feeding relationships of fish in temperate areas.

  1. 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.

  2. 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

  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.

  4. 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

  5. Visual cues eliciting the feeding reaction of a planktivorous fish swimming in a current.

    PubMed

    Mussi, Martina; McFarland, William N; Domenici, Paolo

    2005-03-01

    The visual plankivorous feeding behaviour of the shiner perch (Cymatogaster aggregata) was investigated by means of a flow tank operated at various current speeds. Artemia salina was used as prey. In a second set of experiments, Artemia was darkened with black ink, to compare the visually mediated behaviour of C. aggregata while feeding on dark prey vs feeding on natural (i.e. semi-transparent) prey. The positions of the fish and its prey at the time of the feeding reaction of C. aggregata were measured in three dimensions. Prey were on average closer and more in line with the fish's axis when feeding reactions to darkened Artemia were considered, in comparison with natural Artemia. Three potential mechanisms triggering the feeding reaction of C. aggregata were explored: the prey may trigger a reaction in C. aggregata when it reaches a threshold (1) angular size, (2) angular velocity, or (3) rate of change of the angular size (i.e. loom) of the prey as it is carried passively by the current towards the fish. Our results show that angular velocity may trigger the fish's reaction when using semi-transparent prey, while loom may trigger the reaction to darkened prey. This suggests that feeding behaviour of planktivorous fish is flexible and can use different cues to trigger a motor reaction to prey with different visual characteristics. The feeding reaction appeared to occur at longer distances for semi-transparent rather than darkened Artemia. We suggest that semi-transparent Artemia were visible at greater distances because of their higher scattering (i.e. diffuse reflectance) that made them appear brighter when viewed against a dark background.

  6. 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.

  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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  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. Microbial and nutritional aspects on the production of live feeds in a fish farming industry.

    PubMed

    De Donno, A; Lugoli, F; Bagordo, F; Vilella, S; Campa, A; Grassi, T; Guido, M

    2010-03-01

    Aquaculture is an enterprise in constant development, in particular relating to its effect on the environment and also the quality of its products. It represents a valid alternative to traditional fishing, facing the increasing demand for fish products. To guarantee to the consumer a product of high nutritional, organoleptic and hygienic quality, it is fundamental to monitor every phase of the fish farming industry, isolating the potential risk points. For this reason there has been a rapid evolution of productive technique, particularly in the technology, artificial reproduction and feed sectors. The aim of this research has been the monitoring of the evolution of certain microbial and nutritional quality indexes (total microbial counts and lipid analysis on suspensions of Rotifers and Artemia, used as live feed) in the larval phase of the productive cycle of the farm raised fish, in an intensive system. The study has shown an increment in the total microbial counts in the fish farming industry within the production of Rotifers and Artemia, more evident in the suspensions of Rotifers. In addition the study has demonstrated that the maintenance phase, in the enrichment protocol, can reduce the EPA and DHA content. The results confirm the importance of microbial and nutritional control of the live feeds before they get supplied to fish larvae.

  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. © 2014. Published by The Company of Biologists Ltd.

  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. A simple molecular technique for identifying marine host fish by sequencing blood-feeding parasites.

    PubMed

    Nagel, L; Lougheed, S C

    2006-06-01

    Gnathiid isopods are common ectoparasites of fish on the Great Barrier Reef, Australia. While screening for appropriate markers for phylogenetic studies of gnathiids, we found that primers for 12S and 16S rDNA preferentially amplified the host fish DNA instead of gnathiid DNA. This amplification occurred even when using gnathiids that were not engorged with host blood and adult gnathiids that do not feed on fish blood. This method could be used in host-parasite studies to identify hosts without having to sample parasites directly from the host (which can be costly and requires considerable skill in a marine environment). Target ribosomal DNA sequences can be amplified from total DNA extracted from parasites that are captured in funnel traps or plankton tows. Sequence data from these can be used to identify the hosts that gnathiids were feeding on before capture.

  13. Is the feeding type related with the content of microplastics in intertidal fish gut?

    PubMed

    Mizraji, Ricardo; Ahrendt, Camila; Perez-Venegas, Diego; Vargas, Juan; Pulgar, Jose; Aldana, Marcela; Patricio Ojeda, F; Duarte, Cristian; Galbán-Malagón, Cristobal

    2017-03-15

    Microplastics pollution is a growing global concern that affects all aquatic ecosystems. Microplastics in the environment can be in the form of fibers and/or particles, being the former the most abundant in the marine environment, representing up to 95% of total plastics. The aim of this work was to compare the content of microplastics among intertidal fish with different feeding type. Our results show that omnivorous fish presented a higher amount of microplastic fibers than registered in herbivores and carnivores. Moreover, lower condition factors (K) were found in omnivorous specimens with higher microplastic content. We hypothesized that the type of feeding resulted in different microplastic ingestion, with species with wider range of food sources as omnivores with higher rates. Futures studies carried out to evaluate the biological impacts of microplastics on marine organisms, and microplastics cycling on the marine environment should consider the type of feeding of the studied species. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Comparison study of two procedures for the determination of emamectin benzoate in medicated fish feed.

    PubMed

    Farer, Leslie J; Hayes, John M

    2005-01-01

    A new method has been developed for the determination of emamectin benzoate in fish feed. The method uses a wet extraction, cleanup by solid-phase extraction, and quantitation and separation by liquid chromatography (LC). In this paper, we compare the performance of this method with that of a previously reported LC assay for the determination of emamectin benzoate in fish feed. Although similar to the previous method, the new procedure uses a different sample pretreatment, wet extraction, and quantitation method. The performance of the new method was compared with that of the previously reported method by analyses of 22 medicated feed samples from various commercial sources. A comparison of the results presented here reveals slightly lower assay values obtained with the new method. Although a paired sample t-test indicates the difference in results is significant, this difference is within the method precision of either procedure.

  15. Protective role of Spirulina feed in a freshwater fish (Poecilia reticulata Peters) exposed to an azo dye-methyl red.

    PubMed

    Sharma, Shweta; Sharma, Subhasini; Sharma, K P

    2005-12-01

    Acute toxicity of an azo dye-methyl red (5-40 ppm) was examined under starving conditions, on two groups of Poecilia reticulata--a freshwater fish, fed on different diets prior to their exposure to dye. Besides natural feed, fish of group-1 also received Spirulina feed for one month (feed population), whereas those of group-2 received only natural feed (non-feed population). The mortality data revealed non-feed population to be more tolerant to feed stress during acute toxicity study, whereas feed population exhibited better tolerance to the combined stress of both feed and methyl red; especially at higher concentrations of the latter. RBCs in methyl red treatments acquired different shapes (poikilocytosis) and an increase in their size (anisocytosis) was also noticed. Percentage of such abnormal RBCs was almost equal in both feed and non-feed populations, except at a lower concentration (5 ppm), at which percentage of poikilocytic RBCs was lesser in the feed population. RBC counts in the control non-feed fish (34.5 x 10(4)/mm3) were significantly lower than control feed population (50.0 x 10(4) /mm3). Their number decreased with an increase in methyl red concentrations in non-feed population (9-26%), but percent reduction in RBC counts was almost similar (20-26%) at various concentrations of methyl red (5-30 ppm) in the feed population. Despite reduction in RBC counts, feed population did not suffer from anemia in methyl red treatments, as evident by their RBC counts which were almost equal to control fish of non-feed population. The results suggest that Spirulina feed improves tolerance of test organism towards methyl red manifested by noticeable reduction in the cytotoxic effects on RBCs and a lower mortality rate at higher concentrations of dye.

  16. Acute effects of triclosan, diclofenac and carbamazepine on feeding performance of Japanese medaka fish (Oryzias latipes).

    PubMed

    Nassef, Mohamed; Matsumoto, Shuhei; Seki, Masanori; Khalil, Fatma; Kang, Ik Joon; Shimasaki, Yohei; Oshima, Yuji; Honjo, Tsuneo

    2010-08-01

    The toxicity of three pharmaceutical and personal care products (PPCPs)--carbamazepine (CBMZ), diclofenac (DCF), and triclosan (TCS)--was examined by measuring their effects on feeding behavior and swimming speed of adult Japanese medaka fish (Oryzias latipes). Medaka were exposed to 6.15 mg L(-1) CBMZ, 1.0 mg L(-1) DCF, 0.17 mg L(-1) TCS, or no PPCP (control) for 9 d. Fish behaviors were monitored during days 5-9 of the exposure period. Feeding behavior (time to eat midge larvae, TE) and swimming speed (SS) of individual exposed and control fish were tracked in two dimensions, using an automated system with a digital charge-coupled device camera. As a result, feeding behavior was affected by exposure to CBMZ and DCF, while SS was altered by exposure to CBMZ and TCS. Thus, TCS, DCF and CBMZ appear to affect fish behaviors through different mechanisms. Overall, the results suggest that behavioral changes may provide a sensitive indicator for assessing the toxicity of PPCPs to aquatic organisms. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  17. The fat-1 mouse has brain docosahexaenoic acid levels achievable through fish oil feeding.

    PubMed

    Orr, Sarah K; Tong, Jasmin Y M; Kang, Jing X; Ma, David W L; Bazinet, Richard P

    2010-05-01

    Fat-1 transgenic mice endogenously convert n-6 to n-3 polyunsaturated fatty acids (PUFA). The aims of this study were to test whether a) fish oil feeding can attain similar brain n-3 PUFA levels as the fat-1 mouse, and b) fat-1 mouse brain docosahexaenoic acid (22:6n-3; DHA) levels can be potentiated by fish oil feeding. Fat-1 mice and their wildtype littermates consumed either a 10% safflower oil (SO) or a 2% fish oil and 8% safflower oil chow (FO). Brain total lipid and phospholipid fraction fatty acids were analyzed using GC-FID. Wildtype mice fed FO chow had similar brain levels of DHA as fat-1 mice fed SO chow. Fat-1 mice fed FO chow had similar brain n-3 PUFA levels as fat-1 mice fed SO chow. In conclusion, brain levels of DHA in the fat-1 mouse can be obtained by and were not further augmented with fish oil feeding.

  18. 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.

  19. 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.

  20. Food selectivity and diet switch can explain the slow feeding of herbivorous coral-reef fishes during the morning.

    PubMed

    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.

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

    PubMed

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

    2007-09-18

    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. 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. 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.

  2. Functional feeding responses of piscivorous fishes from the northeast US continental shelf.

    PubMed

    Moustahfid, H; Tyrrell, M C; Link, J S; Nye, J A; Smith, B E; Gamble, R J

    2010-08-01

    The functional feeding response forms of piscivorous fishes used in multispecies and ecosystem modeling have been questioned because they were mostly conjectural or solely based on laboratory studies. Here, we investigate the functional feeding response of seven species of piscivorous fishes on four species of their prey from the northeast US continental shelf using field data that spans 30 years. Our study confirmed that Holling's types II and III functional responses are the most common functional responses for piscivorous fishes in this region. However, our analyses also revealed that differences exist between piscivorous fishes' functional responses, and, therefore, combining functional responses of piscivores is probably not appropriate in multispecies and ecosystem modeling. In the absence of specific predator-prey functional responses, we suggest that, for cruising, actively attacking predators, a type II functional response is slightly preferable; for a sedentary, ambush predator, a type III functional response is slightly preferable; at low prey densities for a generic fish predator, a type III functional response should be used; and at moderate to high prey densities, either should work sufficiently. Because we have shown that the functional response of a particular predator to individual prey species varies, these relationships must be further evaluated as we continue to develop and employ multispecies and ecosystem modeling.

  3. Formulation of a fish feed for goldfish with natural astaxanthin extracted from shrimp waste.

    PubMed

    Weeratunge, W K O V; Perera, B G K

    2016-01-01

    Astaxanthin is a xanthophyll carotenoid, which exhibits many important biological activities including a high degree of antioxidant capacity (AOC) and antibacterial activity, hence has a significant applicability in food, pharmaceutical and cosmetic industries. An attempt was made towards optimization of astaxanthin extraction conditions using three different extraction conditions and a solvent series, from uncooked, cooked and acid-treated shrimp waste, which is a readily available and cheap source of the pigment. The astaxanthin extracts were analyzed by comparing their UV-visible absorbance spectra and thin layer chromatograms with a standard astaxanthin sample. The percentage of astaxanthin in each crude sample was determined using the Beer-Lambert law. The Folin-Ciocalteu assay and the disk diffusion assay were used to investigate the antioxidant capacities and antibacterial activities of extracted astaxanthin samples respectively. The extracted astaxanthin was incorporated into fish feeds to test its ability to enhance the skin color of goldfish. The best astaxanthin percentage of 68 % was observed with the acetone:ethyl acetate (1:1) solvent system facilitated by maceration of cooked and acid treated shrimp, whereas the best crude yield of 33 % was found to be in the acetone extract of the acid-treated shrimp sample. The highest AOC of 65 µg pyrogallol equivalents/mg was observed for the EtOAc extract obtained by maceration of acid-treated shrimp waste. The highest AOC by sonication and soxhlet extraction methods were also obtained with the EtOAc solvent. The extracts exhibited antibacterial activity against four selected bacterial strains. The newly formulated astaxanthin enriched fish feed was economical and indicated a significant improvement of the skin color and healthiness of goldfish compared to the control feeds. Biologically active astaxanthin can be successfully extracted from shrimp waste in higher percentages. The extraction technique and the

  4. 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

  5. Growth and Feed Efficiency of Juvenile Channel Catfish Reared at Different Water Temperatures and Fed Diets Containing Various Levels of Fish Meal

    USDA-ARS?s Scientific Manuscript database

    Channel catfish Ictalurus punctatus do not feed well at low temperatures. It is thought that a diet containing fish meal may enhance feed palatability at low temperatures since fish meal is highly palatable to the fish. There is a lack of information on effects of fish meal levels on growth perfor...

  6. 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.

  7. Feeding strategies and ecological roles of three predatory pelagic fish in the western Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Navarro, Joan; Sáez-Liante, Raquel; Albo-Puigserver, Marta; Coll, Marta; Palomera, Isabel

    2017-06-01

    Knowing the feeding ecology of marine predators is pivotal to developing an understanding of their ecological role in the ecosystem and determining the trophic relationships between them. Despite the ecological importance of predatory pelagic fish species, research on these species in the Mediterranean Sea is limited. Here, by combining analyses of stomach contents and stable isotope values, we examined the feeding strategies of swordfish, Xiphias gladius, little tunny, Euthynnus alletteratus and Atlantic bonito, Sarda sarda, in the western Mediterranean Sea. We also compared the trophic niche and trophic level of these species with published information of other sympatric pelagic predators present in the ecosystem. Results indicated that, although the diet of the three species was composed mainly by fin-fish species, a clear segregation in their main feeding strategies was found. Swordfish showed a generalist diet including demersal species such as blue whiting, Micromesistius poutassou, and European hake, Merluccius merluccius, and pelagic fin-fish such as barracudina species (Arctozenus risso and Lestidiops jayakari) or small pelagic fish species. Little tunny and Atlantic bonito were segregated isotopically between them and showed a diet basically composed of anchovy, Engraulis encrasicolus, and round sardinella, Sardinella aurita, and sardines, Sardina pilchardus, respectively. This trophic segregation, in addition to potential segregation by depth, is likely a mechanism that allows their potential coexistence within the same pelagic habitat. When the trophic position of these three predatory pelagic fish species is compared with other pelagic predators such as bluefin tuna, Thunnus thynnus, and dolphinfish, Coryphaena hippurus, present in the western Mediterranean Sea, we found that they show similar intermediate trophic position in the ecosystem. In conclusion, the combined stomach and isotopic results highlight, especially for little tunny and Atlantic

  8. A standard deviation selection in evolutionary algorithm for grouper fish feed formulation

    NASA Astrophysics Data System (ADS)

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

    2016-10-01

    Malaysia is one of the major producer countries for fishery production due to its location in the equatorial environment. Grouper fish is one of the potential markets in contributing to the income of the country due to its desirable taste, high demand and high price. However, the demand of grouper fish is still insufficient from the wild catch. Therefore, there is a need to farm grouper fish to cater to the market demand. In order to farm grouper fish, there is a need to have prior knowledge of the proper nutrients needed because there is no exact data available. Therefore, in this study, primary data and secondary data are collected even though there is a limitation of related papers and 30 samples are investigated by using standard deviation selection in Evolutionary algorithm. Thus, this study would unlock frontiers for an extensive research in respect of grouper fish feed formulation. Results shown that the fitness of standard deviation selection in evolutionary algorithm is applicable. The feasible and low fitness, quick solution can be obtained. These fitness can be further predicted to minimize cost in farming grouper fish.

  9. Feeding guilds and food resource partitioning in a lake fish assemblage: an ontogenetic approach.

    PubMed

    Specziár, A; Rezsu, E T

    2009-07-01

    Ontogenetic diet patterns and trophic guild structure of a 15 species temperate lake fish assemblage were analysed over wide size intervals (up to seven orders of magnitude in body mass), representing practically the whole life span in most species. A two-step objective clustering technique supplemented with other multivariate statistical tools proved that size-related diet changes clearly played an important role in structuring trophic organization of fishes inhabiting Lake Balaton. As many as 13 out of the 15 fish species showed marked size-related dietary changes with two to four ontogenetic feeding stages. At the assemblage level, 11 trophic guilds were separated. Guild membership was size-dependent in 11 fish species that participated in two to four trophic guilds during their life span. The most complex trophic ontogeny was observed in roach Rutilus rutilus and asp Aspius aspius with four guild memberships. This study showed that trophic status of fishes may be very size-sensitive and thus a universal classification of fish species to general trophic guilds, such as 'planktivore', 'benthivore', 'piscivore' or 'herbivore', should be applied very carefully even in environmental monitoring and fisheries management applications, unless it is supported by relevant results of life span diet analyses.

  10. Latitudinal and taxonomic patterns in the feeding ecologies of fish larvae: A literature synthesis

    NASA Astrophysics Data System (ADS)

    Llopiz, Joel K.

    2013-01-01

    The longtime focus on factors that influence the survival of marine fish larvae has yielded an extensive number of studies on larval fish diets and feeding success. In light of a recent increase in such studies within lower latitudes, results from the peer-reviewed literature were synthesized to examine both latitudinal and taxonomic differences in several trophic-related categories, including feeding incidence, trophic niche breadth, ontogenetic diet shifts, dominant prey types, diet broadness, and larval piscivory. A total of 204 investigations (taxon-article combinations) contained suitable results for at least one of these categories. Feeding incidences (proportions of larvae containing food) were significantly higher in lower latitudes with all taxa combined, as well as only within the order Perciformes. Feeding incidences also differed among orders, with Perciformes and Scorpaeniformes having the highest values. The number of larval taxa exhibiting a significantly increasing niche breadth (SD of the log of prey sizes) with larval size decreased toward lower latitudes, with some taxa in lower latitudes exhibiting a decrease in niche breadth with size. The frequency of exhibiting ontogenetic diets shifts decreased with decreasing latitude, as did relative diet broadness (a function of prey types). The most common dominant prey types in the diets of higher latitude larvae were nauplii and calanoid copepods, with cyclopoids being rare in higher latitudes. Dominant prey types in lower latitudes were more diverse, with nauplii, calanoids, and cyclopoids being equally important. Appendicularians increased in importance with decreasing latitude, and one of the clearest latitudinal distinctions was the display of larval piscivory (almost exclusively by scombroid taxa), which was highly concentrated in lower latitudes. Overall, the latitudinal differences observed for multiple trophic-related factors highlight inherent distinctions in larval fish feeding ecologies

  11. The feeding habits of slope dwelling macrourid fishes in the eastern North Pacific

    NASA Astrophysics Data System (ADS)

    Drazen, Jeffrey C.; Buckley, Troy W.; Hoff, Gerald R.

    2001-03-01

    The diet of slope dwelling macrourid fishes in the eastern North Pacific is poorly known. We collected several hundred stomach samples to investigate the feeding habits of Coryphaenoides acrolepis and Albatrossia pectoralis, the two dominant slope dwelling macrourids off the continental United States. Coryphaenoides acrolepis exhibited a pronounced ontogenetic shift in diet. Specimens <15 cm pre-anal fin length (PAF) consumed primarily polychaetes, amphipods, cumaceans and mysids, while larger individuals consumed increasingly larger, more pelagic prey such as fish, squid, and large crustaceans. Scavenging was also very important to specimens >15 cm with scavenged food constituting approximately 20% of the weight of total prey and occurring in approximately 20% of fish 21-29 cm. Albatrossia pectoralis consumed primarily midwater fish and squid, and we believe that it feeds in the water column. There were significant differences between the diets of A. pectoralis and C. acrolepis suggesting some degree of niche separation between macrourid species on the continental slope of the eastern North Pacific. Both species are at the top of the food web on the upper continental slope and, because of their abundance, may exert significant pressures on their prey populations.

  12. Small Marine Protected Areas in Fiji Provide Refuge for Reef Fish Assemblages, Feeding Groups, and Corals

    PubMed Central

    Pires, Mathias M.; Guimarães, Paulo Roberto; Hoey, Andrew S.; Hay, Mark E.

    2017-01-01

    The establishment of no-take marine protected areas (MPAs) on coral reefs is a common management strategy for conserving the diversity, abundance, and biomass of reef organisms. Generally, well-managed and enforced MPAs can increase or maintain the diversity and function of the enclosed coral reef, with some of the benefits extending to adjacent non-protected reefs. A fundamental question in coral reef conservation is whether these benefits arise within small MPAs (<1 km2), because larval input of reef organisms is largely decoupled from local adult reproduction. We examined the structure of fish assemblages, composition of fish feeding groups, benthic cover, and key ecosystem processes (grazing, macroalgal browsing, and coral replenishment) in three small (0.5–0.8 km2) no-take MPAs and adjacent areas where fisheries are allowed (non-MPAs) on coral reefs in Fiji. The MPAs exhibited greater species richness, density, and biomass of fishes than non-MPAs. Furthermore, MPAs contained a greater abundance and biomass of grazing herbivores and piscivores as well as a greater abundance of cleaners than fished areas. We also found differences in fish associations when foraging, with feeding groups being generally more diverse and having greater biomass within MPAs than adjacent non-MPAs. Grazing by parrotfishes was 3–6 times greater, and macroalgal browsing was 3–5 times greater in MPAs than in non-MPAs. On average, MPAs had 260–280% as much coral cover and only 5–25% as much macroalgal cover as their paired non-MPA sites. Finally, two of the three MPAs had three-fold more coral recruits than adjacent non-MPAs. The results of this study indicate that small MPAs benefit not only populations of reef fishes, but also enhance ecosystem processes that are critical to reef resilience within the MPAs. PMID:28122006

  13. Small Marine Protected Areas in Fiji Provide Refuge for Reef Fish Assemblages, Feeding Groups, and Corals.

    PubMed

    Bonaldo, Roberta M; Pires, Mathias M; Guimarães, Paulo Roberto; Hoey, Andrew S; Hay, Mark E

    2017-01-01

    The establishment of no-take marine protected areas (MPAs) on coral reefs is a common management strategy for conserving the diversity, abundance, and biomass of reef organisms. Generally, well-managed and enforced MPAs can increase or maintain the diversity and function of the enclosed coral reef, with some of the benefits extending to adjacent non-protected reefs. A fundamental question in coral reef conservation is whether these benefits arise within small MPAs (<1 km2), because larval input of reef organisms is largely decoupled from local adult reproduction. We examined the structure of fish assemblages, composition of fish feeding groups, benthic cover, and key ecosystem processes (grazing, macroalgal browsing, and coral replenishment) in three small (0.5-0.8 km2) no-take MPAs and adjacent areas where fisheries are allowed (non-MPAs) on coral reefs in Fiji. The MPAs exhibited greater species richness, density, and biomass of fishes than non-MPAs. Furthermore, MPAs contained a greater abundance and biomass of grazing herbivores and piscivores as well as a greater abundance of cleaners than fished areas. We also found differences in fish associations when foraging, with feeding groups being generally more diverse and having greater biomass within MPAs than adjacent non-MPAs. Grazing by parrotfishes was 3-6 times greater, and macroalgal browsing was 3-5 times greater in MPAs than in non-MPAs. On average, MPAs had 260-280% as much coral cover and only 5-25% as much macroalgal cover as their paired non-MPA sites. Finally, two of the three MPAs had three-fold more coral recruits than adjacent non-MPAs. The results of this study indicate that small MPAs benefit not only populations of reef fishes, but also enhance ecosystem processes that are critical to reef resilience within the MPAs.

  14. 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.

  15. 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

  16. Environmental and Water Quality Operational Studies. Prey Selection and Feeding Patterns of Fish in a Southern United States Hydropower Tailwater.

    DTIC Science & Technology

    1985-10-01

    peaking hydropower generation at Lake Hartwell /4. Georgia -South Carolina, on the diel prey selection and feeding of four species of fish--silver redhorse...releases on the feeding of fish. Materials and Methods 2. The tailwater of Lake Hartwell is that reach of the Savannah River between Georgia and South...Carolina extending 15-20 km downstream from Hartwell Dam (Figure 1). During generation of peaking hydropower 3 I Hartwel Lake StStation 2 !~ Or g S

  17. Investigation of selected persistent organic pollutants in farmed Atlantic salmon (Salmo salar), salmon aquaculture feed, and fish oil components of the feed.

    PubMed

    Jacobs, Miriam N; Covaci, Adrian; Schepens, Paul

    2002-07-01

    There is extensive literature documenting the bioaccumulation of persistent organic pollutants in the marine environment, but relatively little data are available on contamination pathways in aquaculture systems such as that for farmed salmon. In recent years,the salmon industry has grown significantly in Europe. This study reports on the determination of a wide range of polychlorinated biphenyls (PCBs), organochlorine pesticides, and polybrominated diphenyl ethers (PBDEs) in farmed and wild European Atlantic salmon fish, aquaculture feeds, and fish oils used to supplement the feeds. The study confirms previous reports of relatively high concentrations of PCBs and indicates moderate concentrations of organochlorine pesticides and PBDEs in farmed Scottish and European salmon. Concentrations of the selected persistent organic pollutants varied among the samples: PCBs (salmon, 145-460 ng/g lipid; salmon feeds, 76-1153 ng/g lipid; fish oils, 9-253 ng/g lipid), S DDTs (salmon, 5-250 ng/g lipid; salmon feeds, 34-52 ng/g lipid; fish oils, 11-218 ng/g lipid), and PBDEs (salmon, 1-85 ng/g lipid: salmon feeds, 8-24 ng/g lipid; fish oils, ND-13 ng/g lipid). Comparison of the samples for all groups of contaminants, except for HCHs, showed an increase in concentration in the order fish oil < feed < salmon. Homologue profiles were similar, with an increase in contribution of hepta- and octa-PCBs in the fish, and profiles of DDTs were similar in all three types of samples. With a constant contribution to the total PCB content, the ICES 7 PCBs appear to be reliable predictors of the PCB contamination profile through all the samples. For PBDEs, BDE 47 dominated the profiles, with no significant difference in the PBDE profiles for the three matrixes. Samples with higher PCB contents generally showed higher levels of the pesticide residues, but this was not the case with the PBDEs, indicating the existence of different pollution sources.

  18. An investigation of enhanced mercury bioaccumulation in fish from offshore feeding.

    PubMed

    Chételat, John; Cloutier, Louise; Amyot, Marc

    2013-08-01

    We investigated the dietary pathways of mercury transfer in the food web of Morency Lake (Canada) to determine the influence of carbon source and habitat use on mercury bioaccumulation in fish. Whole-body concentrations of methylmercury (MeHg) were significantly different in four fish species (white sucker, brown bullhead, pumpkinseed and smallmouth bass) and increased with both trophic position and greater feeding on offshore (versus littoral) carbon. An examination of fish gut contents and the depth distribution of invertebrates in Morency Lake showed that smallmouth bass and brown bullhead were supplementing their littoral diet with the consumption of either opossum shrimp (Mysis diluviana) or profundal amphipods in offshore waters. The zooplanktivore Mysis had significantly higher MeHg concentrations than zooplankton and benthic invertebrates, and it was an elevated source of MeHg to smallmouth bass. In contrast, profundal amphipods consumed by brown bullhead did not have higher MeHg concentrations than littoral amphipods. Instead, partitioning of benthic invertebrate resources likely explains the greater MeHg bioaccumulation in brown bullhead, associated with offshore feeding of amphipods. White sucker and brown bullhead had a similar trophic position but white sucker consumed more chironomids, which had one-third the MeHg concentration of amphipods. Our findings suggest that offshore feeding in a lake can affect fish MeHg bioaccumulation via two different processes: (1) the consumption of MeHg-enriched pelagic prey, or (2) resource partitioning of benthic primary consumers with different MeHg concentrations. These observations on the mechanisms of habitat-specific bioaccumulation highlight the complexity of MeHg transfer through lake food webs.

  19. Feeding complementarity versus redundancy among herbivorous fishes on a Caribbean reef

    NASA Astrophysics Data System (ADS)

    Burkepile, D. E.; Hay, M. E.

    2011-06-01

    Herbivory is an important driver of community structure on coral reefs. Adequate understanding of herbivory will mandate better knowledge of how specific herbivores impact reef communities and the redundancy versus complementarity of their ecological roles. We used algal communities generated by herbivore manipulations to assess such roles among Caribbean herbivorous fishes. We created large enclosures on a 16- to 18-m-deep reef to create treatments grazed for 10 months by: (1) only Sparisoma aurofrenatum, (2) only Acanthurus bahianus, (3) no large herbivorous fishes, or (4) natural densities of all reef fishes. After 10 months, we removed cages and filmed how free-ranging reef fishes fed among these treatments that differed in algal community structure. In general, Acanthurus spp. and Scarus spp. rapidly grazed exclosure and Sparisoma-only treatments, while Sparisoma spp. preferentially grazed exclosure and Acanthurus-only treatments. These patterns suggest complementarity between Sparisoma spp. and both Acanthurus spp. and Scarus spp. but redundancy between Acanthurus spp. and Scarus spp. Despite these generalities, there was also within-genera variance in response to the different treatments. For example, large Scarus spp., such as Scarus guacamaia, fed more similarly to Sparisoma spp., particularly Sparisoma viride, than to other Scarus spp. Moreover, the three common Sparisoma species differed considerably in the macroalgae to which they exhibited positive or negative relationships. Thus, herbivorous reef fishes vary considerably in their response to different algal communities and exhibit complex patterns of compensatory feeding and functional redundancy that are poorly predicted by taxonomy alone.

  20. 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

  1. Monitoring Escape and Feeding Behaviours of Cruiser Fish by Inertial and Magnetic Sensors

    PubMed Central

    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

  2. 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.

  3. 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.

  4. Particle retention in suspension-feeding fish after removal of filtration structures.

    PubMed

    Smith, Jennifer C; Sanderson, S Laurie

    2013-12-01

    The suspension-feeding cichlids Oreochromis aureus (blue tilapia) and Oreochromis esculentus (ngege tilapia) are able to selectively retain small food particles. The gill rakers and microbranchiospines of these species have been assumed to function as filters. However, surgical removal of these oral structures, which also removed associated mucus, did not significantly affect the total number of 11-200 μm particles ingested by the fish. This result supports the hypothesis that the branchial arch surfaces themselves play an important role in crossflow filtration. Both species selectively retained microspheres greater than 50 μm with gill rakers and microbranchiospines intact as well as removed, demonstrating that neither these structures nor mucus are necessary for size selectivity to occur during biological crossflow filtration. After removal of the gill rakers and microbranchiospines, O. esculentus retained significantly more microspheres 51-70 μm in diameter and fewer 91-130 μm microspheres compared to retention with intact structures, but the particle size selectivity of O. aureus was not affected significantly. These results support conclusions from previous computational fluid dynamics simulations indicating that particle size can have marked effects on particle trajectory and retention inside the fish oropharyngeal cavity during crossflow filtration. The substantial inter-individual variability in particle retention by suspension-feeding fish is an unexplored area of research with the potential to increase our understanding of the factors influencing particle retention during biological filtration.

  5. 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.

  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. "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

  8. Comparative analyses of contaminant levels in bottom feeding and predatory fish using the National Contaminant Biomonitoring Program data

    SciTech Connect

    Kidwell, J.M.; Phillips, L.J.; Birchard, G.F.

    1995-06-01

    Both bottom feeding and predatory fish accumulate chemical contaminants found in water. Bottom feeders are readily exposed to the greater quantities of chlorinated hydrocarbons and metals that accumulate in sediments. Predators, on the other hand, may bioaccumulate organochlorine pesticides, PCBs, and metals from the surrounding water or from feeding on other fish, including bottom feeders, which may result in the biomagnification of these compounds in their tissues. This study used National Contaminant Biomonitoring Program data produced by the Fish and Wildlife Service to test the hypothesis that differences exist between bottom feeders and predators in tissue levels of organochlorine pesticides, PCBs, and metals. 7 refs., 2 tabs.

  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.

  10. Sucking while swimming: evaluating the effects of ram speed on suction generation in bluegill sunfish Lepomis macrochirus using digital particle image velocimetry.

    PubMed

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

    2005-07-01

    It is well established that suction feeding fish use a variable amount of swimming (ram) during prey capture. However, the fluid mechanical effects of ram on suction feeding are not well established. In this study we quantified the effects of ram on the maximum fluid speed of the water entering the mouth during feeding as well as the spatial patterns of flow entering the mouth of suction-feeding bluegill sunfish Lepomis macrochirus. Using Digital Particle Image Velocimetry (DPIV) and high-speed video, we observed the flow in front of the mouth of three fish using a vertical laser sheet positioned on the mid-sagittal plane of the fish. From this we quantified the maximum fluid speed (measured at a distance in front of the mouth equal to one half of the maximum mouth diameter), the degree of focusing of water flow entering the mouth, and the shape of the ingested volume of water. Ram speed in 41 feeding sequences, measured at the time of maximum gape, ranged between 0 and 25 cm s(-1), and the ratio of ram speed to fluid speed ranged from 0.1% to 19.1%. In a regression ram speed did not significantly affect peak fluid speed, but with an increase in ram speed the degree of focusing of water entering the mouth increased significantly, and the shape of the ingested volume of water became more elongate and narrow. The implications of these findings are that (1) suction feeders that employ ram of between 0% and 20% of fluid speed sacrifice little in terms of the fluid speeds they generate and (2) ram speed enhances the total body closing speed of the predator.

  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.

  13. Trophic position of bottom-feeding fish in the Upper Paraná River floodplain.

    PubMed

    Lopes, C A; Benedito, E; Martinelli, L A

    2009-06-01

    The delta15N composition of bottom-feeding fish (iliophagous = Apareiodon affinis, Cyphocharax nagelii, Prochilodus lineatus, Steindachnerina brevipinna and S. insculpta; detritivorous = Loricariichthys platymetopon and Liposarcus anisitsi; benthophagous = Satanoperca pappaterra and Hoplosternum littorale) and their primary food sources were investigated in the upper Paraná River floodplain during rainy seasons in different environments (lotic and lentic). Two hypotheses were tested: i) that the trophic position and isotopic values of the investigated organisms (fish and food resources) vary spatially; and ii) that trophic position and isotopic compositions differ among iliophagous, detritivorous and benthophagous fish. C4 macrophytes, periphyton and phytoplankton were isotopically different in sites analyzed. Significant isotopic differences occurred in the species of each trophic category. Spatial differences were observed in the isotopic composition of P. lineatus and L. platymetopon, whose values were more enriched in the Paraná River and Pau Véio Lake. Significant spatial differences in trophic position were observed for L. platymetopon and H. littorale, which presented the highest values in the Paraná and Baía rivers, respectively. Trophic positions were significantly different among the species that composed each trophic category. These findings demonstrate that in energy-flow studies in detrital food chains generalizations concerning the grouping of fish into trophic categories and/or habitats should only be carried out after careful investigations of the local/specific trophic dynamics of the organisms.

  14. The first direct evidence of a Late Devonian coelacanth fish feeding on conodont animals

    NASA Astrophysics Data System (ADS)

    Zatoń, Michał; Broda, Krzysztof; Qvarnström, Martin; Niedźwiedzki, Grzegorz; Ahlberg, Per Erik

    2017-04-01

    We describe the first known occurrence of a Devonian coelacanth specimen from the lower Famennian of the Holy Cross Mountains, Poland, with a conodont element preserved in its digestive tract. A small spiral and phosphatic coprolite (fossil excrement) containing numerous conodont elements and other unrecognized remains was also found in the same deposits. The coprolite is tentatively attributed to the coelacanth. Although it is unclear whether the Late Devonian coelacanth from Poland was an active predator or a scavenger, these finds provide the first direct evidence of feeding on conodont animals by early coelacanth fish, and one of the few evidences of feeding on these animals known to date. It also expands our knowledge about the diet and trophic relations between the Paleozoic marine animals in general.

  15. Effects of Glyphosate-Based Herbicide Sub-Lethal Concentrations on Fish Feeding Behavior.

    PubMed

    Giaquinto, Percilia Cardoso; de Sá, Marina Borges; Sugihara, Vanessa Seiko; Gonçalves, Bruno Bastos; Delício, Helton Carlos; Barki, Assaf

    2017-04-01

    Glyphosate-based herbicides are widely used in agricultural systems. Although the target organism are particularly plant organisms, there are numerous studies showing adverse effects in aquatic animals, such as inhibition of acetyl cholinesterase, effects on kidney, liver, and gill and stressors effects. This study analyzed the effects of commercial formulation of glyphosate on feeding behavior in Pacu (Piaractus mesopotamicus). Fish were exposed to three glyphosate concentrations (0.2, 0.6, and 1.8 ppm) for 15 days. At concentrations of 0.2 and 0.6 ppm, food intake decreased on day 13 and then returned to normal on day 15. At the highest glyphosate-based herbicide concentration, 1.8 ppm, food consumption decreased dramatically and did not recover on day 15. This study showed that glyphosate-based herbicide at sub-lethal concentrations can affect feed intake in pacu and consequently inhibits its growth.

  16. The first direct evidence of a Late Devonian coelacanth fish feeding on conodont animals.

    PubMed

    Zatoń, Michał; Broda, Krzysztof; Qvarnström, Martin; Niedźwiedzki, Grzegorz; Ahlberg, Per Erik

    2017-04-01

    We describe the first known occurrence of a Devonian coelacanth specimen from the lower Famennian of the Holy Cross Mountains, Poland, with a conodont element preserved in its digestive tract. A small spiral and phosphatic coprolite (fossil excrement) containing numerous conodont elements and other unrecognized remains was also found in the same deposits. The coprolite is tentatively attributed to the coelacanth. Although it is unclear whether the Late Devonian coelacanth from Poland was an active predator or a scavenger, these finds provide the first direct evidence of feeding on conodont animals by early coelacanth fish, and one of the few evidences of feeding on these animals known to date. It also expands our knowledge about the diet and trophic relations between the Paleozoic marine animals in general.

  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. Effect of production quotas on economic and environmental values of growth rate and feed efficiency in sea cage fish farming

    PubMed Central

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

    2017-01-01

    In sea cage fish farming, production quotas aim to constrain the impact of fish farming on the surrounding ecosystem. It is unknown how these quotas affect economic profitability and environmental impact of genetic improvement. We combined bioeconomic modelling with life cycle assessment (LCA) to calculate the economic (EV) and environmental (ENV) values of thermal growth coefficient (TGC) and feed conversion ratio (FCR) of sea bass reared in sea cages, given four types of quota commonly used in Europe: annual production (Qprod), annual feed distributed (Qannual_feed), standing stock (Qstock), and daily feed distributed (Qdaily_feed). ENV were calculated for LCA impact categories climate change, eutrophication and acidification. ENV were expressed per ton of fish produced per year (ENV(fish)) and per farm per year (ENV(farm)). Results show that irrespective of quota used, EV of FCR as well as ENV(fish) and ENV(farm) were always positive, meaning that improving FCR increased profit and decreased environmental impacts. However, the EV and the ENV(fish) of TGC were positive only when quota was Qstock or Qdaily_feed. Moreover, the ENV(farm) of TGC was negative in Qstock and Qdaily_feed quotas, meaning that improving TGC increased the environmental impact of the farm. We conclude that Qstock quota and Qdaily_feed quota are economically favorable to a genetic improvement of TGC, a major trait for farmers. However, improving TGC increases the environmental impact of the farm. Improving FCR represents a good opportunity to balance out this increase but more information on its genetic background is needed to develop breeding programs improving FCR. PMID:28288179

  19. Effect of production quotas on economic and environmental values of growth rate and feed efficiency in sea cage fish farming.

    PubMed

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

    2017-01-01

    In sea cage fish farming, production quotas aim to constrain the impact of fish farming on the surrounding ecosystem. It is unknown how these quotas affect economic profitability and environmental impact of genetic improvement. We combined bioeconomic modelling with life cycle assessment (LCA) to calculate the economic (EV) and environmental (ENV) values of thermal growth coefficient (TGC) and feed conversion ratio (FCR) of sea bass reared in sea cages, given four types of quota commonly used in Europe: annual production (Qprod), annual feed distributed (Qannual_feed), standing stock (Qstock), and daily feed distributed (Qdaily_feed). ENV were calculated for LCA impact categories climate change, eutrophication and acidification. ENV were expressed per ton of fish produced per year (ENV(fish)) and per farm per year (ENV(farm)). Results show that irrespective of quota used, EV of FCR as well as ENV(fish) and ENV(farm) were always positive, meaning that improving FCR increased profit and decreased environmental impacts. However, the EV and the ENV(fish) of TGC were positive only when quota was Qstock or Qdaily_feed. Moreover, the ENV(farm) of TGC was negative in Qstock and Qdaily_feed quotas, meaning that improving TGC increased the environmental impact of the farm. We conclude that Qstock quota and Qdaily_feed quota are economically favorable to a genetic improvement of TGC, a major trait for farmers. However, improving TGC increases the environmental impact of the farm. Improving FCR represents a good opportunity to balance out this increase but more information on its genetic background is needed to develop breeding programs improving FCR.

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

    PubMed

    Purnell, Mark A

    2002-01-07

    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.

  1. 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.

  2. 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

  3. 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.

  4. Rapid determination of tyramine in fish feed and slaughter offal by HPLC using coulometric detection.

    PubMed

    Vuorela, H; Hinkkanen, R; Hiltunen, R

    1989-11-01

    Fish feed and slaughter offal products may contain decomposition compounds such as biogenic amines. Owing to their harmful effects on animals fed with such products, there is a need for determining the amine content. In the work a simple and fast HPLC method, based on coulometric detection (EC) measuring only tyramine, was developed for routine quality screening. The samples were extracted with 0.4 mol/L perchloric acid and analysed directly by HPLC using a mobile phase of 0.2 mol/L potassium dihydrogen phosphate in water at pH 3. Tyramine was detected using a coulometric detector consisting of two analytical cells, the first one at 0.4 V and the second at 0.7 V. The calibration was linear over the range 4.52 to 452 ng/ml. The minimum detectable quantity was 10 pg/20 microliters. The reproducibility and the recoveries were high. Comparison of the tyramine content measured by EC or derivatization followed by ultraviolet detection showed that both methods gave similar results. HPLC using EC is a fast and sensitive method for analysing tyramine reliably in fish feed and slaughter offal samples without any time-consuming derivatization steps.

  5. 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

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

    PubMed

    Friedman, Matt

    2012-03-07

    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.

  7. 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

  8. 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

    2015-11-17

    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

  9. Comparative lever analysis and ontogenetic scaling in esocid fishes: Functional demands and constraints in feeding biomechanics.

    PubMed

    Goulet, Courtney L; Smith, Harrison J; Maie, Takashi

    2016-11-01

    When animals grow, the functional demands that they experience often change as a consequence of their increasing body size. In this study, we examined the feeding biomechanics in esocid species that represent different size classes (small, Esox americanus; intermediate, Esox niger; large, Esox lucius), and how their bite forces and associated functional variables change as they grow. In order to evaluate bite performance through ontogeny, we dissected and measured dimensions of the feeding apparatus and the adductor mandibulae muscle complex with its segmentum facialis subdivisions such as the ricto-malaris, stegalis and endoricto-malaris across a wide range of body sizes. The collected morphological data was used as input variables for a published anatomical model to simulate jaw function in these fish species. Maximum bite forces for both anterior bite and posterior bite increased in isometry in E. americanus and E. niger. The posterior bite of E. lucius also increases in isometry, however, the anterior bite increases in positive allometry. Intraspecific comparison within E. lucius indicated the increase of bite forces in more developed individuals accelerated after the fish grew out of fingerling stage. In addition, our analysis indicated functional differentiation between subdivisions of the adductor mandibulae segmentum facialis, as well as interspecific differences in the pattern of contribution to the bite performance by these subdivisions. Our study provides insights into not only the musculoskeletal basis of the jaw function of esocid species, but also the feeding capacity of this species in relation to the functional demands it faces as one of the top predators in lake and river systems. J. Morphol. 277:1447-1458, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  10. 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.

  11. Determination of emamectin benzoate in medicated fish feed: a multisite study.

    PubMed

    Farer, Leslie J

    2005-01-01

    A new method was developed for the quantitation of emamectin benzoate in medicated fish feed at levels between 1 and 30 ppm. The new procedure, based on a previously reported assay, consists of a wet methanolic extraction of ground feed, followed by solid-phase extraction and injection onto a gradient liquid chromatographic system. A multisite study involving 3 laboratories (the developing laboratory and 2 independent laboratories) was performed to evaluate precision, recovery, linearity, and sensitivity. Mean recove;ries for triplicate analyses at 3 levels, performed by 2 analysts per laboratory, were between 89 and 97%, with coefficients of variation ranging from 1.6 to 8.6%. Coefficients of determination (r2) obtained from the plotted data were > or =0.993. The precision of the method, determined from 6 replicate preparations from the same batch of medicated feed assayed in 3 separate trials per laboratory, was between 0.6 and 5.8%. The quantitation limit was established at 0.5 ppm. Specificity and robustness studies were performed by the developing laboratory.

  12. 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

  13. 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.

  14. Development and validation of a multi-analyte method for the regulatory control of carotenoids used as feed additives in fish and poultry feed.

    PubMed

    Vincent, Ursula; Serano, Federica; von Holst, Christoph

    2017-08-01

    Carotenoids are used in animal nutrition mainly as sensory additives that favourably affect the colour of fish, birds and food of animal origin. Various analytical methods exist for their quantification in compound feed, reflecting the different physico-chemical characteristics of the carotenoid and the corresponding feed additives. They may be natural products or specific formulations containing the target carotenoids produced by chemical synthesis. In this study a multi-analyte method was developed that can be applied to the determination of all 10 carotenoids currently authorised within the European Union for compound feedingstuffs. The method functions regardless of whether the carotenoids have been added to the compound feed via natural products or specific formulations. It is comprised of three steps: (1) digestion of the feed sample with an enzyme; (2) pressurised liquid extraction; and (3) quantification of the analytes by reversed-phase HPLC coupled to a photodiode array detector in the visible range. The method was single-laboratory validated for poultry and fish feed covering a mass fraction range of the target analyte from 2.5 to 300 mg kg(-)(1). The following method performance characteristics were obtained: the recovery rate varied from 82% to 129% and precision expressed as the relative standard deviation of intermediate precision varied from 1.6% to 15%. Based on the acceptable performance obtained in the validation study, the multi-analyte method is considered fit for the intended purpose.

  15. 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.

  16. 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.

  17. 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.

  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. Feeding biology of a guild of benthivorous fishes in a sandy shore on south-eastern Brazilian coast.

    PubMed

    Zahorcsak, P; Silvano, R A; Sazima, I

    2000-08-01

    The feeding biology of eight species of benthivorous fishes was studied in a sandy shore at Anchieta Island, south-eastern Brazilian coast. The fishes fed mainly on Amphipoda and Mysidacea crustaceans. The diet of the most abundant species, the drum Umbrina coroides, was analyzed in three standard length classes (20-55, 56-90 and 91-135 mm). This sciaenid showed an ontogenetic diet shift from Mysidacea to Amphipoda. The feeding behaviour of the sciaenid U. coroides and the gerreid Eucinostomus gula was recorded while snorkeling. During their foraging both species uncovered small organisms buried in the sand. Notwithstanding general similarities in diet, U. coroides and E. gula presented differences in feeding behaviour and morphology. Two carangid species of the genus Trachinotus differed in diet composition and consumed a larger array of food items than the remaining fish species. Differences in diet and feeding activity between the remaining benthivorous species were noted. These differences possibly reduce overlap in resource use and favour the coexistence of guilds of benthivorous fishes on sandy shores.

  20. Gas chromatography-triple quadrupole tandem mass spectrometry: a powerful tool for the (ultra)trace analysis of multiclass environmental contaminants in fish and fish feed.

    PubMed

    Kalachova, Kamila; Pulkrabova, Jana; Cajka, Tomas; Drabova, Lucie; Stupak, Michal; Hajslova, Jana

    2013-09-01

    A new method for rapid determination of 73 target organic environmental contaminants including 18 polychlorinated biphenyls, 16 organochlorinated pesticides, 14 brominated flame retardants and 25 polycyclic aromatic hydrocarbons in fish and fish feed using gas chromatography coupled with triple quadrupole tandem mass spectrometry (GC-MS/MS) was developed and validated. GC-MS/MS in electron ionization mode was shown to be a powerful tool for the (ultra)trace analysis of multiclass environmental contaminants in complex matrices, providing measurements with high selectivity and sensitivity. Another positive aspect characterizing the newly developed method is a substantial simplification of the sample preparation, which was achieved by an ethyl acetate QuEChERS (quick, easy, cheap, effective, rugged and safe) based extraction followed by silica minicolumn clean-up. With use of this sample preparation approach the sample laboratory throughput was increased not only because six samples may be prepared in approximately 1 h, but also because all the above-mentioned groups of contaminants can be determined in a single GC-MS/MS run. Under the optimized conditions, the recoveries of all target analytes in both matrices were within the range from 70 to 120% and the repeatabilities were 20% or less. The method quantification limits were in the range from 0.005 to 1 μg kg(-1) and from 0.05 to 10 μg kg(-1) for fish muscle tissue and fish feed, respectively. The developed method was successfully applied to the determination of halogenated persistent organic pollutants and polycyclic aromatic hydrocarbons in fish and fish feed samples.

  1. Effects of fish oil replacement and re-feeding on the bioaccumulation of organochlorine compounds in gilthead sea bream (Sparus aurata L.) of market size.

    PubMed

    Nácher-Mestre, Jaime; Serrano, Roque; Benedito-Palos, Laura; Navarro, Juan C; López, Francisco J; Pérez-Sánchez, Jaume

    2009-08-01

    Organochlorine pesticide residues and polychlorinated biphenyls were determined in raw materials, fish feeds and fillets from fish exposed through the productive cycle (14 months) to experimental diets with different percentages of fish oil replacement with vegetable oils. Detectable amounts of organochlorine compounds were found in raw materials derived from fish sources with none being detected in vegetable ingredients. Fish feeds presented trace concentrations of contaminants at the ng/g level, which varied according to the contribution of the different resources used in their manufacture. Contaminants did not accumulate during the first 11 months of exposure, and low concentrations of organochlorine compounds were found both at the start and at the end of this feeding period. Fillets from fish fed the fish oil diet presented the highest concentrations of organochlorine compounds, with these decreasing in proportion to fish oil replacement. Three months of fish oil re-feeding during the finishing phase only produced significant bioaccumulation over the course of the first month. By optimizing fish meal and fish oil replacement with vegetable oils alternative feeds can contribute to significantly reduce the risk of organochlorine uptake by consumers.

  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. A broader look at ammonia production, excretion, and transport in fish: a review of impacts of feeding and the environment.

    PubMed

    Bucking, Carol

    2017-01-01

    For nearly a century, researchers have studied ammonia production and excretion in teleost fish. Stemming from past investigations a body of knowledge now exists on various aspects including biochemical mechanisms of ammonia formation and specific routes and tissues used for ammonia transport, culminating in a current detailed theoretical model of branchial transport, including the molecular identities of the moieties involved. However, typical studies examining ammonia balance use routine laboratory conditions and fasted fish. While avoiding additional variables that influence nitrogen balance, these studies are arguably idealistic and do not reflect the natural variety of conditions that fish encounter. Further studies have revealed the impacts of extrinsic factors (e.g. salinity, pH, temperature) on ammonia handling in fasted fish whereas others have explored intrinsic factors, such as life history and developmental impacts. One routine challenge for ammonia balance that fish encounter is feeding and digestion. Fortunately, many new studies have revealed the impact of feeding and digestion on several aspects of ammonia balance; from production to excretion and to transport, and several have done so incorporating supplemental extrinsic and/or intrinsic factors. Together, these complex studies reveal realistic responses to multifactorial challenges encountered by animals in the wild and begin to provide a holistic view of ammonia balance in freshwater teleost fish.

  4. Determination of oxytetracycline/oxytetracycline hydrochloride in animal feed, fish feed, and veterinary medicinal products by liquid chromatography with fluorescence detection: collaborative study.

    PubMed

    Thiex, Nancy J; Larson, Richard

    2009-01-01

    A method for determining oxytetracycline (OTC) in animal feed, fish feed, and veterinary medicinal products at medicated use and contamination levels was collaboratively studied. The method is applicable to the analysis of animal feeds and mineral premixes containing levels > or =2 mg/kg, and fish feed containing levels > or =10 mg/kg. Oxytetracycline hydrochloride (OTC.HCI) is extracted from ground feed material in acid-methanol solution using mechanical agitation. After centrifugation for 5 min at 1230 x g, an aliquot of the extract is diluted with water andlor acid-methanol so that the concentration of OTC.HCI is approximately the same as that in the working standard, and the solutions contain at least 50% water. Injectable veterinary medicinal materials (also called animal remedy materials) are diluted with water andlor extractant to reach the target concentration. The extracts are filtered and analyzed by reversed-phase liquid chromatography with fluorescence detection with excitation at 390 nm and emission at 512 nm. Twenty-eight test samples of medicated feeds, supplements, and drug premixes, including 4 test samples for trace-level analysis, were sent to 17 collaborators in Canada, The Netherlands, and the United States. Results were received from 11 laboratories. The RSDr values (within-laboratory repeatability) ranged from 1.26 to 9.21%; RSDR values (among-laboratory reproducibility) ranged from 2.14 to 12.9%, and HorRat values ranged from 0.54 to 3.02. It is recommended that this method be adopted AOAC Official First Action.

  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.

  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. Development of a novel casein-protamine based microparticles for early feeding of fish larvae: in vitro evaluation.

    PubMed

    Cara, Beatriz; Moyano, Francisco J; Gander, Bruno; Yúfera, Manuel

    2007-09-01

    The objective of this study was to develop novel type of protein walled microparticles suitable for using in early feeding of fish larvae. The microparticles were made of casein and protamine through complex coacervation and did not require further cross-linking or use of environmentally problematic reagents. The methodology was oriented to generate microparticles with an appropriate size range for easy recognition and ingestion by fish larvae (50-200 microm), adequate floating properties in saline, sufficient stability in terms of protein leakage and appropriate digestibility by the gut enzymes of fish larvae. Desired particle size and stability against protein leakages over 8 h were successfully achieved by optimizing the coacervation process conditions. The floating properties under static conditions were considered appropriate as a main particle fraction remained in suspension during at least 10 min. Very importantly, an enzyme extract from larval gut readily digested the particles. The digestibility of the casein-protamine particles was similar to that measured for Artemia nauplii and for two previously developed casein-based microparticles produced by interfacial polymerization and ionic gelation; the latter microparticle type had previously achieved good results of digestibility in early feeding of marine fish larvae. The in vitro evaluation of the newly developed casein-protamine microparticles revealed promising characteristics as artificial larval feed. Thus, these particles merit further development with respect to entrapping nutrients and testing them in larval cultures for their nutritional value.

  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. Stress, nutrition and parental care in a teleost fish: exploring mechanisms with supplemental feeding and cortisol manipulation.

    PubMed

    Zolderdo, A J; Algera, D A; Lawrence, M J; Gilmour, K M; Fast, M D; Thuswaldner, J; Willmore, W G; Cooke, S J

    2016-04-15

    Parental care is an essential life-history component of reproduction for many animal species, and it entails a suite of behavioural and physiological investments to enhance offspring survival. These investments can incur costs to the parent, reducing their energetic and physiological condition, future reproductive capabilities and survival. In fishes, relatively few studies have focused on how these physiological costs are mediated. Male smallmouth bass provide parental care for developing offspring until the brood reaches independence. During this energetically demanding life stage, males cease active foraging as they vigorously defend their offspring. Experimental manipulation of cortisol levels (via implantation) and food (via supplemental feeding) in parental males was used to investigate the fitness consequences of parental care. Improving the nutritional condition of nest-guarding males increased their reproductive success by reducing premature nest abandonment. However, supplemental feeding and cortisol treatment had no effect on parental care behaviours. Cortisol treatment reduced plasma lymphocyte numbers, but increased neutrophil and monocyte concentrations, indicating a shift in immune function. Supplemental feeding improved the physiological condition of parental fish by reducing the accumulation of oxidative injury. Specifically, supplemental feeding reduced the formation of 8-hydroxy-2'-deoxyguanosine (8-OHdG) on DNA nucleotides. Increasing the nutritional condition of parental fish can reduce the physiological cost associated with intensive parental activity and improve overall reproductive success, illustrating the importance of nutritional condition as a key modulator of parental fitness. © 2016. Published by The Company of Biologists Ltd.

  10. The Ecology and Feeding Habits of Fish Assemblages Closely Associated with Offshore Oil and Gas Platforms in the North Sea

    NASA Astrophysics Data System (ADS)

    Fujii, T.

    2016-02-01

    Despite the large number of offshore oil and gas platforms currently installed in the North Sea, little is known about the role of such large fixed offshore structures in the ecology of fish populations in this region. This presentation reports the results of the first detailed study on feeding habits of fish assemblages closely associated with offshore oil/gas platforms in the North Sea. Multi-seasonal fish sampling was conducted at one of the oil platforms located in the Central North Sea (September 2010 - January 2014), and the results revealed that commercially important gadoids such as saithe (Pollachius virens), haddock (Melanogrammus aeglefinus) and cod (Gadus morhua) were the most abundant species. Saithe fed predominantly on euphausiids and haddock consumed large proportion of ophiuroids, whereas cod were mainly piscivorous. Their prey compositions were significantly different between species, indicating individual offshore installations could provide unique feeding grounds for a variety of fish species and thereby allow for interspecific prey resource partitioning among those species closely associated with the structure. To further investigate possible links between the feeding habits of the most dominant fish species, saithe, and the physical presence of offshore platforms across the North Sea, a separate set of stomach data were collected during the 2012 Q3 International Bottom Trawl Survey. The multivariate analysis showed the observed spatio-temporal variability in saithe diet was significantly explained by proximity to the nearest offshore platforms and changes in water temperatures, which appear to reflect patterns of euphausiid availability over space and time. The physical presence of the offshore structures may affect the distribution/availability of euphausiids and thereby influence the feeding behaviour of saithe and possibly other marine populations that are interconnected to the dynamics of such trophic interactions in the North Sea.

  11. Impact of medicated feed on the development of antimicrobial resistance in bacteria at integrated pig-fish farms in Vietnam.

    PubMed

    Dang, Son Thi Thanh; Petersen, Andreas; Van Truong, Dung; Chu, Huong Thi Thanh; Dalsgaard, Anders

    2011-07-01

    Integrated livestock-fish aquaculture utilizes animal excreta, urine, and feed leftovers as pond fertilizers to enhance the growth of plankton and other microorganisms eaten by the fish. However, antimicrobial-resistant bacteria may be transferred and develop in the pond due to selective pressure from antimicrobials present in animal feed, urine, and feces. In an experimental pig-fish farm located in periurban Hanoi, Vietnam, nine piglets were provided feed containing 5 μg of tetracycline (TET)/kg pig weight/day and 0.45 μg of enrofloxacin (ENR)/kg pig weight/day during the second and fourth (last) months of the experiment. The aim of this study was to determine the association between the provision of pig feed with antimicrobials and the development of antimicrobial resistance, as measured in a total of 520 Escherichia coli and 634 Enterococcus strains isolated from pig manure and water-sediment pond samples. MIC values for nalidixic acid (NAL) and ENR showed that E. coli and Enterococcus spp. overall exhibited significant higher frequencies of resistance toward NAL and ENR during the 2 months when pigs were administered feed with antimicrobials, with frequencies reaching 60 to 80% in both water-sediment and manure samples. TET resistance for both indicators was high (>80%) throughout the study period, which indicates that TET-resistant E. coli and Enterococcus spp. were present in the piglets before the initiation of the experiment. PCR-based identification showed similar relative occurrences of Enterococcus faecium, Enterococcus faecalis, and other Enterococcus spp. in the water-sediment and manure samples, suggesting that Enterococcus spp. isolated in the ponds originated mainly from the pig manure. The development of antimicrobial resistance in integrated animal husbandry-fish farms and possible transfers and the impact of such resistance on food safety and human health should be further assessed.

  12. [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.

  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. Effect of magnesium peroxide biostimulation of fish feed-loaded marine sediments on changes in the bacterial community.

    PubMed

    Santander-De Leon, Sheila Mae S; Okunishi, Suguru; Kihira, Masaki; Nakano, Miyo; Nuñal, Sharon N; Hidaka, Masayasu; Yoshikawa, Takeshi; Maeda, Hiroto

    2013-01-01

    The effect of an oxygen-releasing compound (ORC) magnesium peroxide (MgO(2)) on the changes in the bacterial community in organically polluted sediment of aquaculture farms was tested in a microcosm experiment. The sediment, to which fish feed was added, was treated with 1% or 5% MgO(2). The addition of fish feed induced a highly reduced environment with low redox potential, high total sulfides, and abundance of sulfate-reducing bacteria (SRB) . Although the sediment remained highly reduced at 1% MgO(2), there was a significant reduction of total sulfides, increase of redox potential, and resultant reduction of SRB. The bacterial community clearly changed with the treatments according to denaturing gradient gel electrophoresis (DGGE) analysis of 16S ribosomal RNA gene (16S rDNA) . Aerobes disappeared in the fish feed-added sediment, and some SRB emerged in place of these aerobes. On the other hand, the SRB disappeared in the ORC-amended sediment due to its highly oxic condition. This study revealed the bacterial community in the sediments was affected mainly by the redox potential and resultant sulfides produced by SRB, but total organic carbon and nitrogen were not determinants of the microbial population.

  15. 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.

  16. Computational fluid dynamics in the oral cavity of ram suspension-feeding fishes.

    PubMed

    Cheer, A Y; Ogami, Y; Sanderson, S L

    2001-06-21

    We have modeled steady, three-dimensional flow with a no-slip boundary condition in cylindrical and conical oral cavities possessing vertical or slanted branchial slits. These numerical simulations illustrate the transport of food particles toward the esophagus, as well as the velocity profiles of water exiting the oral cavity via the branchial slits. The maximum and average velocities are highest for flow exiting the most posterior branchial slit. The highest volume flow rates also occur in the most posterior slit for the cylindrical simulations, but occur in the most anterior slit for the conical simulations. Along the midline, there is a pronounced bilaterally symmetrical vortex in the posterodorsal region of the cylindrical and conical oral cavities and a second bilaterally symmetrical vortex in the posteroventral region of the cylinder. Particles entrained in the vortices will recirculate in the posterior oral cavity, increasing the probability of encounter with sticky, mucus-covered surfaces such as the oral roof, gill arches, or gill rakers. The posterodorsal vortex could serve to concentrate particles near the entrances of the epibranchial organs. The ventral vortex could be involved in sequestering dense inorganic particles that sink toward the floor of the oral cavity. All vortices are absent in the conical simulation with vertical branchial slits, indicating that the slanted branchial slits between the gill arches are responsible for the formation of the vortex in the conical oral cavity. Experiments using in vivo flow visualization techniques are needed to determine whether ram suspension feeders, pump suspension feeders, and non-suspension-feeding fishes possess vortices in the posterior oral cavity that contribute to particle transport, food particle encounter with sticky surfaces, and inorganic particle rejection. Copyright 2001 Academic Press.

  17. LC-MS/MS methods for albendazole analysis in feed and its metabolite residues in fish fillet and a leaching study in feed after an alternative procedure for drug incorporation.

    PubMed

    Busatto, Zenaís; da Silva, Agnaldo Fernando Baldo; de Freitas, Osvaldo; Paschoal, Jonas Augusto Rizzato

    2017-04-01

    This paper describes the development of analytical methods for the quantification of albendazole (ABZ) in fish feed and ABZ and its main known metabolites (albendazole sulfoxide, albendazole sulfone and albendazole aminosulfone) in fish fillet employing LC-MS/MS. In order to assess the reliability of the analytical methods, evaluation was undertaken as recommended by related guides proposed by the Brazilian Ministry of Agriculture for analytical method validation. The calibration curve for ABZ quantification in feed showed adequate linearity (r > 0.99), precision (CV < 1.03%) and trueness ranging from 99% to 101%. The method for ABZ residues in fish fillet involving the QuEChERS technique for sample extraction had adequate linearity (r > 0.99) for all analytes, precision (CV < 13%) and trueness around 100%, with CCα < 122 ng g(-)(1) and CCβ < 145 ng g(-)(1). Besides, by aiming to avoid the risk of ABZ leaching from feed into the aquatic environment during fish medication via the oral route, a promising procedure for drug incorporation in the feed involving coating feed pellets with ethyl cellulose polymer containing ABZ was also evaluated. The medicated feed had good homogeneity (CV < 3%) and a lower release of ABZ (< 0.2%) from feed to water when the medicated feed stayed in the water for up to 15 min.

  18. 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.

  19. 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.

  20. First Known Feeding Trace of the Eocene Bottom-Dwelling Fish Notogoneus osculus and Its Paleontological Significance

    PubMed Central

    Martin, Anthony J.; Vazquez-Prokopec, Gonzalo M.; Page, Michael

    2010-01-01

    Background The Green River Formation (early Eocene, about 42–53 Ma) at and near Fossil Butte National Monument in Wyoming, USA, is world famous for its exquisitely preserved freshwater teleost fish in the former Fossil Lake. Nonetheless, trace fossils attributed to fish interacting with the lake bottom are apparently rare, and have not been associated directly with any fish species. Here we interpret the first known feeding and swimming trace fossil of the teleost Notogoneus osculus Cope (Teleostei: Gonorynchidae), which is also represented as a body fossil in the same stratum. Methodology/Principal Findings A standard description of the trace fossil, identified as Undichna cf. U. simplicatas, was augmented by high-resolution digital images and spatial and mathematical analyses, which allowed for detailed interpretations of the anatomy, swimming mode, feeding behavior, and body size of the tracemaker. Our analysis indicates that the tracemaker was about 45 cm long; used its caudal, anal, and pelvic fins (the posterior half of its body) to make the swimming traces; and used a ventrally oriented mouth to make overlapping feeding marks. We hypothesize that the tracemaker was an adult Notogoneus osculus. Conclusions/Significance Our results are the first to link a specific teleost tracemaker with a trace fossil from the Green River Formation, while also interpreting the size and relative age of the tracemaker. The normal feeding and swimming behaviors indicated by the trace fossil indicate temporarily oxygenated benthic conditions in the deepest part of Fossil Lake, counter to most paleoecological interpretations of this deposit. Lastly, our spatial and mathematical analyses significantly update and advance previous approaches to the study of teleost trace fossils. PMID:20463969

  1. Thermal Resilience of Feeding Kinematics May Contribute to the Spread of Invasive Fishes in Light of Climate Change

    PubMed Central

    Turingan, Ralph; Sloan, Tyler

    2016-01-01

    As a consequence of global warming, tropical invasive species are expected to expand their range pole-ward, extending their negative impacts to previously undisturbed, high-latitude ecosystems. Investigating the physiological responses of invasive species to environmental temperature is important because the coupled effects of climate change and species invasion on ecosystems could be more alarming than the effects of each phenomenon independently. Especially in poikilotherms, the rate of motion in muscle-driven biomechanical systems is expected to double for every 10 °C increase in temperature. In this study, we address the question, “How does temperature affect the speed of jaw-movement during prey-capture in invasive fishes?” Kinematic analysis of invasive-fish prey-capture behavior revealed that (1) movement velocities of key components of the feeding mechanism did not double as water temperature increased from 20 °C to 30 °C; and (2) thermal sensitivity (Q10 values) for gape, hyoid, lower-jaw rotation, and cranial rotation velocities at 20 °C and 30 °C ranged from 0.56 to 1.44 in all three species. With the exception of lower-jaw rotation, Q10 values were significantly less than the expected Q10 = 2.0, indicating that feeding kinematics remains consistent despite the change in environmental temperature. It is conceivable that the ability to maintain peak performance at different temperatures helps facilitate the spread of invasive fishes globally. PMID:27897997

  2. Thermal Resilience of Feeding Kinematics May Contribute to the Spread of Invasive Fishes in Light of Climate Change.

    PubMed

    Turingan, Ralph; Sloan, Tyler

    2016-11-25

    As a consequence of global warming, tropical invasive species are expected to expand their range pole-ward, extending their negative impacts to previously undisturbed, high-latitude ecosystems. Investigating the physiological responses of invasive species to environmental temperature is important because the coupled effects of climate change and species invasion on ecosystems could be more alarming than the effects of each phenomenon independently. Especially in poikilotherms, the rate of motion in muscle-driven biomechanical systems is expected to double for every 10 °C increase in temperature. In this study, we address the question, "How does temperature affect the speed of jaw-movement during prey-capture in invasive fishes?" Kinematic analysis of invasive-fish prey-capture behavior revealed that (1) movement velocities of key components of the feeding mechanism did not double as water temperature increased from 20 °C to 30 °C; and (2) thermal sensitivity (Q10 values) for gape, hyoid, lower-jaw rotation, and cranial rotation velocities at 20 °C and 30 °C ranged from 0.56 to 1.44 in all three species. With the exception of lower-jaw rotation, Q10 values were significantly less than the expected Q10 = 2.0, indicating that feeding kinematics remains consistent despite the change in environmental temperature. It is conceivable that the ability to maintain peak performance at different temperatures helps facilitate the spread of invasive fishes globally.

  3. LC-MS/MS methods for sulfadimethoxine and ormetoprim analysis in feed and fish fillet and a leaching study for feed after alternative procedures for the incorporation of drugs.

    PubMed

    Fais, Ana Paula; Franco, Rodolfo Scarpino Barboza; da Silva, Agnaldo Fernando Baldo; de Freitas, Osvaldo; Paschoal, Jonas Augusto Rizzato

    2017-04-01

    This paper describes the method development for sulfadimethoxine (SDM) and ormetoprim (OMP) quantitation in fish feed and fish fillet employing LC-MS/MS. In order to assess the reliability of the analytical method, valuation was undertaken as recommended by guidelines proposed by the Brazilian Ministry of Agriculture. The calibration curve for the quantification of both drugs in feed showed adequate linearity (r > 0.99), precision (CV < 12%) and trueness ranging from 97% to 100%. The method for the determination of SDM and OMP residues in fish fillet involved a simple sample preparation procedure that had adequate linearity (r > 0.99), precision (CV < 16%) and trueness around 100%, with CCα < 100.2 ng g(-)(1) and CCβ < 100.4 ng g(-)(1). With a goal of avoiding the risk of drug leaching from feed into the aquatic environment during fish medication via the oral route, different procedures for drug incorporation into feed were evaluated. Coating feed pellets with ethyl cellulose polymer containing the drug showed promising results. In this case, medicated feed released drugs to water at a level below 6% when the medicated feed stayed in the water for up to 15 min.

  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. © 2013 SETAC.

  5. 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.

  6. The influence of fish feed pellets on the stability of seabed sediment: A laboratory flume investigation

    NASA Astrophysics Data System (ADS)

    Neumeier, Urs; Friend, Patrick L.; Gangelhof, Uffe; Lunding, Jens; Lundkvist, Morten; Bergamasco, Alessandro; Amos, Carl L.; Flindt, Mogens

    2007-11-01

    Superfluous fish food settling below fish farms can have a negative impact on the seabed. To aid in the assessment of this impact a series of flume experiments, designed to mimic seabed conditions below a fish farm, was conducted with the aim of examining the effects of fish pellets on the stability of fine sediments. Artificial beds, with varying quantities of fish pellets incorporated both within the sediment matrix and lying on the sediment surface, were allowed to consolidate for different periods of time ranging from 1 to 10 days, and then subjected to erosion experiments. In flume experiments containing fish pellets, a bacterial biofilm developed at the sediment-water interface after a few days. In the control experiments (no fish pellets), a diatom biofilm caused extensive stabilisation of the surface sediment. The erosion experiments showed that the addition of fish pellets reduced the surface erosion threshold by more than 50%. The stability decrease was more pronounced in the experiments with greater amounts of pellets. Evidence of drag reduction due to high suspended sediment concentration was also observed. This phenomenon is discussed and a correction formula is proposed for the effective shear stress experienced by the bed.

  7. A toothless dwarf dolphin (Odontoceti: Xenorophidae) points to explosive feeding diversification of modern whales (Neoceti).

    PubMed

    Boessenecker, Robert W; Fraser, Danielle; Churchill, Morgan; Geisler, Jonathan H

    2017-08-30

    Toothed whales (Odontoceti) are adapted for catching prey underwater and possess some of the most derived feeding specializations of all mammals, including the loss of milk teeth (monophyodonty), high tooth count (polydonty), and the loss of discrete tooth classes (homodonty). Many extant odontocetes possess some combination of short, broad rostra, reduced tooth counts, fleshy lips, and enlarged hyoid bones-all adaptations for suction feeding upon fishes and squid. We report a new fossil odontocete from the Oligocene (approx. 30 Ma) of South Carolina (Inermorostrum xenops, gen. et sp. nov.) that possesses adaptations for suction feeding: toothlessness and a shortened rostrum (brevirostry). Enlarged foramina on the rostrum suggest the presence of enlarged lips or perhaps vibrissae. Phylogenetic analysis firmly places Inermorostrum within the Xenorophidae, an early diverging odontocete clade typified by long-snouted, heterodont dolphins. Inermorostrum is the earliest obligate suction feeder within the Odontoceti, a feeding mode that independently evolved several times within the clade. Analysis of macroevolutionary trends in rostral shape indicate stabilizing selection around an optimum rostral shape over the course of odontocete evolution, and a post-Eocene explosion in feeding morphology, heralding the diversity of feeding behaviour among modern Odontoceti. © 2017 The Author(s).

  8. Routine oro/nasopharyngeal suction versus no suction at birth.

    PubMed

    Foster, Jann P; Dawson, Jennifer A; Davis, Peter G; Dahlen, Hannah G

    2017-04-18

    Oro/nasopharyngeal suction is a method used to clear secretions from the oropharynx and nasopharynx through the application of negative pressure via a suction catheter or bulb syringe. Traditionally, airway oro/nasopharyngeal suction at birth has been used routinely to remove fluid rapidly from the oropharynx and nasopharynx in vigorous and non-vigorous infants at birth. Concerns relating to the reported adverse effects of oro/nasopharyngeal suctioning led to a practice review and routine oro/nasopharyngeal suctioning is no longer recommended for vigorous infants. However, it is important to know whether there is any clear benefit or harm for infants whose oro/nasopharyngeal airway is suctioned compared to infants who are not suctioned. To evaluate the effect of routine oropharyngeal/nasopharyngeal suction compared to no suction on mortality and morbidity in newly born infants. We used the standard search strategy of the Cochrane Neonatal Review group to search the Cochrane Central Register of Controlled Trials (CENTRAL 2016, Issue 3), MEDLINE via PubMed (1966 to April 18, 2016), Embase (1980 to April 18, 2016), and CINAHL (1982 to April 18, 2016). We also searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials. Randomised, quasi-randomised controlled trials and cluster randomised trials that evaluated the effect of routine oropharyngeal/nasopharyngeal suction compared to no suction on mortality and morbidity in newly born infants with and without meconium-stained amniotic fluid. The review authors extracted from the reports of the clinical trials, data regarding clinical outcomes including mortality, need for resuscitation, admission to neonatal intensive care, five minute Apgar score, episodes of apnoea and length of hospital stay. Eight randomised controlled trials met the inclusion criteria and only included term infants (n = 4011). Five studies

  9. The comparative feeding ecology of temperate and tropical deep-sea fishes from the western North Atlantic

    NASA Astrophysics Data System (ADS)

    Crabtree, R. E.; Carter, J.; Musick, J. A.

    1991-10-01

    A study of the feeding habits of 32 species of fishes from the continental slope, rise, and abyss of temperate and tropical regions of the western North Atlantic was conducted to ascertain if regional faunal differences were related to differences in trophic structure. Fishes consumed a wide variety of benthic and pelagic prey and appear to have diets comparable to their counterparts on the continental shelf. Commonly occurring small to moderate sized species fed predominately on small crustaceans and polychaetes, while less common large-bodied species igested decapods and teleosts and displayed ontogenetic shifts in diets. In some cases, presence or absence of a particular taxon from the respective areas appears related to food availability, although no single causal factor adequately explains all of the observed faunal differences.

  10. Evaluation of commercial marine fish feeds for production of juvenile cobia in recirculating aquaculture systems

    USDA-ARS?s Scientific Manuscript database

    The effect of feeding three commercially available diets manufactured by three U.S. feed companies on production characteristics and body composition of juvenile cobia Rachycentron canadum reared in recirculating aquaculture systems (RAS) was evaluated in a 57 d growth trial. Juvenile cobia (26.7 +...

  11. Altered feeding habits and strategies of a benthic forage fish (Fundulus heteroclitus) in chronically polluted tidal salt marshes.

    PubMed

    Goto, Daisuke; Wallace, William G

    2011-07-01

    Responses in feeding ecology of a benthic forage fish, mummichogs (Fundulus heteroclitus), to altered prey resources were investigated in chronically polluted salt marshes (the Arthur Kill-AK, New York, USA). The diet niche breadth of the AK populations of mummichogs was significantly lower than that of the reference population, reflecting reduced benthic macroinfaunal species diversity. Most of the AK populations also had 2-3 times less food in their gut than the reference population. This disparity in gut fullness among the populations appeared to be partly due to ingested prey size shifts; some of the AK populations ingested fewer large prey than the reference population. Furthermore, benthic assemblages were strongly associated with sediment-associated mercury; gut fullness of the AK populations also significantly decreased with increasing mercury body burdens. These results indicate that chronic pollution may have directly (chemical bioaccumulation) and indirectly (reduced prey availability) altered the feeding ecology of mummichogs.

  12. 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. © 2014. Published by The Company of Biologists Ltd.

  13. Early enteral feeding in postsurgical cancer patients. Fish oil structured lipid-based polymeric formula versus a standard polymeric formula.

    PubMed Central

    Kenler, A S; Swails, W S; Driscoll, D F; DeMichele, S J; Daley, B; Babineau, T J; Peterson, M B; Bistrian, B R

    1996-01-01

    OBJECTIVES: The authors compared the safety, gastrointestinal tolerance, and clinical efficacy of feeding an enteral diet containing a fish oil/medium-chain triglyceride structured lipid (FOSL-HN) versus an isonitrogenous, isocaloric formula (O-HN) in patients undergoing major abdominal surgery for upper gastrointestinal malignancies. SUMMARY BACKGROUND DATA: Previous studies suggest that feeding with n-3 fatty acids from fish oil can alter eicosanoid and cytokine production, yielding an improved immunocompetence and a reduced inflammatory response to injury. The use of n-3 fatty acids as a structured lipid can improve long-chain fatty acid absorption. METHODS: This prospective, blinded, randomized trial was conducted in 50 adult patients who were jejunally fed either FOSL-HN or O-HN for 7 days. Serum chemistries, hematology, urinalysis, gastrointestinal complications, liver and renal function, plasma and erythrocyte fatty acid analysis, urinary prostaglandins, and outcome parameters were measured at baseline and on day 7. Comparisons were made in 18 and 17 evaluable patients based a priori on the ability to reach a tube feeding rate of 40 mL/hour. RESULTS: Patients receiving FOSL-HN experienced no untoward side effects, significant incorporation of eicosapentaenoic acid into plasma and erythrocyte phospholipids, and a 50% decline in the total number of gastrointestinal complications and infections compared with patients given O-HN. The data strongly suggest improved liver and renal function during the postoperative period in the FOSL-HN group. CONCLUSION: Early enteral feeding with FOSL-HN was safe and well tolerated. Results suggest that the use of such a formula during the postoperative period may reduce the number of infections and gastrointestinal complications per patient, as well as improve renal and liver function through modulation of urinary prostaglandin levels. Additional clinical trials to fully quantify clinical benefits and optimize nutritional

  14. 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.

  15. 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.

  16. Terrestrial-style feeding in a very early aquatic tetrapod is supported by evidence from experimental analysis of suture morphology

    PubMed Central

    Markey, Molly J.; Marshall, Charles R.

    2007-01-01

    There is no consensus on when in the fish-tetrapod transition suction feeding, the primary method of prey capture in the aquatic realm, evolved into the direct biting on prey typical of terrestrial animals. Here, we show that differences in the morphology of selected cranial sutures between species that span the fish–tetrapod transition (the Devonian osteolepiform fish Eusthenopteron, the aquatic Devonian tetrapod Acanthostega, and the Permian terrestrial tetrapod Phonerpeton) can be used to infer when terrestrial feeding first appeared. Our approach consists of defining a sutural morphospace, assigning functional fields to that morphospace based on our previous measurements of suture function made during feeding in the living fish Polypterus, inferring the functions of the fossil sutures based on where they fall in the morphospace, and then using the correlation between feeding mode and the patterns of inferred suture function across the skull roof in taxa where feeding mode is unambiguous to infer the feeding mode practiced by Acanthostega. Using this procedure, we find that the suture morphologies of Acanthostega are inconsistent with the hypothesis that it captured prey primarily by means of suction, which suggests that it may have bitten directly on prey at or near the water's edge. Thus, our data strongly support the hypothesis that the terrestrial mode of feeding first emerged in aquatic taxa. PMID:17438285

  17. Optimal diets in complex environments: feeding strategies of two herbivorous fishes from a temperate rocky intertidal zone.

    PubMed

    Horn, M H

    1983-06-01

    The seasonal diets of Cebidichthys violaceus and Xiphister mucosus, two herbivorous fishes from the complex, multifood environment of the central California rocky intertidal zone, were partially consistent with three predictions of optimal diet models based on energy maximization: 1) The prediction that at high food densities a forager should concentrate solely on the energetically most valuable items was incompletely met by these two fish species. C. violaceus and X. mucosus increased their consumption of energy-rich annual macrophytes during periods (summer and fall) of high food abundance, but nevertheless continued to take a mixed diet. 2) The prediction that abundance of lower-valued foods does not determine their inclusion in the diet was largely upheld by the feeding habits of these two intertidal fishes. The probability of an item being consumed apparently depends upon its abundance as well as its chemical composition. 3) The prediction that foragers will generalize as food abundance declines was largely met by the two fishes since their diets broadened considerably during periods (e.g. winter) of reduced food supply. Furthermore, diets of the two species converged during periods of high food abundance and diverged during months of low food abundance. Whether this seasonal pattern of overlap was due to interspecific competition or other factors is unknown. This study, in agreement with other recent investigations, indicates that optimal diet models cannot be based solely on energy maximization but should also include nutrient constraints in order to more accurately predict the seasonally fluctuating mixed diets of these fishes and other generalist herbivores.

  18. Engineered maize as a source of astaxanthin: processing and application as fish feed.

    PubMed

    Breitenbach, Jürgen; Nogueira, Marilise; Farré, Gemma; Zhu, Changfu; Capell, Teresa; Christou, Paul; Fleck, Gunther; Focken, Ulfert; Fraser, Paul D; Sandmann, Gerhard

    2016-12-01

    Astaxanthin from a transgenic maize line was evaluated as feed supplement source conferring effective pigmentation of rainbow trout flesh. An extraction procedure using ethanol together with the addition of vegetal oil was established. This resulted in an oily astaxanthin preparation which was not sufficiently concentrated for direct application to the feed. Therefore, a concentration process involving multiple phase partitioning steps was implemented to remove 90 % of the oil. The resulting astaxanthin raw material contained non-esterified astaxanthin with 12 % 4-keto zeaxanthin and 2 % zeaxanthin as additional carotenoids. Isomeric analysis confirmed the exclusive presence of the 3S, 3'S astaxanthin enantiomer. The geometrical isomers were 89 % all-E, 8 % 13-Z and 3 % 9-Z. The incorporation of the oily astaxanthin preparation into trout feed was performed to deliver 7 mg/kg astaxanthin in the final feed formulation for the first 3.5 weeks and 72 mg/kg for the final 3.5 weeks of the feeding trial. The resulting pigmentation of the trout fillets was determined by hue values with a colour meter and further confirmed by astaxanthin quantification. Pigmentation properties of the maize-produced natural astaxanthin incorporated to 3.5 µg/g dw in the trout fillet resembles that of chemically synthesized astaxanthin. By comparing the relative carotenoid compositions in feed, flesh and feces, a preferential uptake of zeaxanthin and 4-keto zeaxanthin over astaxanthin was observed.

  19. Growth performance and feed utilization of keureling fish Tor tambra (Cyprinidae) fed formulated diet supplemented with enhanced probiotic.

    PubMed Central

    Muchlisin, Zainal Abidin; Murda, Tanzil; Yulvizar, Cut; Dewiyanti, Irma; Fadli, Nur; Afrido, Fardin; Siti-Azizah, Mohd Nor; Muhammadar, Abdullah A.

    2017-01-01

    Background The objective of the present study was to determine the optimum dosage of probiotic in the diet of keureling fish ( Tor tambra) fry. Methods Lactobacillus casei from Yakult® was used as a starter, and enhanced with Curcuma xanthorrhiza, Kaempferia galanga and molasses. The mixture was fermented for 7 days prior to use as probiotic in a formulated diet containing 30% crude protein. Four levels of probiotic dosage; 0 ml kg -1 (control), 5 ml kg -1, 10 ml kg -1 and 15 ml kg -1 were tested in this study. The fish was fed twice a day at 08.00 AM and 06.00 PM at the ration of 5% body weight for 80 days. Results The results showed that growth performance and feed efficiency increased with increasing probiotic dosage in the diet from control (no probiotic) to 10 ml kg -1 of probiotic dosage and then decreased when the dosage was increased up to 15 ml kg -1. Conclusions The best values for all measured parameters were recorded at the dosage of 10 ml kg -1. Therefore, it was concluded that the optimum dosage of enhanced probiotic for T. tambra fry was 10 ml kg -1 of feed. PMID:28357045

  20. Growth performance and feed utilization of keureling fish Tor tambra (Cyprinidae) fed formulated diet supplemented with enhanced probiotic.

    PubMed

    Muchlisin, Zainal Abidin; Murda, Tanzil; Yulvizar, Cut; Dewiyanti, Irma; Fadli, Nur; Afrido, Fardin; Siti-Azizah, Mohd Nor; Muhammadar, Abdullah A

    2017-01-01

    Background The objective of the present study was to determine the optimum dosage of probiotic in the diet of keureling fish ( Tor tambra) fry. MethodsLactobacillus casei from Yakult® was used as a starter, and enhanced with Curcuma xanthorrhiza, Kaempferia galanga and molasses. The mixture was fermented for 7 days prior to use as probiotic in a formulated diet containing 30% crude protein. Four levels of probiotic dosage; 0 ml kg (-1) (control), 5 ml kg (-1), 10 ml kg (-1) and 15 ml kg (-1) were tested in this study. The fish was fed twice a day at 08.00 AM and 06.00 PM at the ration of 5% body weight for 80 days. Results The results showed that growth performance and feed efficiency increased with increasing probiotic dosage in the diet from control (no probiotic) to 10 ml kg (-1) of probiotic dosage and then decreased when the dosage was increased up to 15 ml kg (-1). Conclusions The best values for all measured parameters were recorded at the dosage of 10 ml kg (-1). Therefore, it was concluded that the optimum dosage of enhanced probiotic for T. tambra fry was 10 ml kg (-1) of feed.

  1. 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

  2. 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

  3. 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.

  4. 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

  5. Functional feed assessment on Litopenaeus vannamei using 100% fish meal replacement by soybean meal, high levels of complex carbohydrates and Bacillus probiotic strains.

    PubMed

    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.

  6. 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.

  7. 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.

  8. Is there enough zooplankton to feed forage fish populations off Peru? An acoustic (positive) answer

    NASA Astrophysics Data System (ADS)

    Ballón, Michael; Bertrand, Arnaud; Lebourges-Dhaussy, Anne; Gutiérrez, Mariano; Ayón, Patricia; Grados, Daniel; Gerlotto, François

    2011-12-01

    The Northern Humboldt Current system (NHCS) produces more fish per unit area than any other region in the world. Although the system produces enough macrozooplankton to sustain its high production of forage fish, the paucity of information on macrozooplankton hampers research into the system. In this study, we estimated the biomass of the epipelagic crustacean macrozooplankton from the NHCS during both austral summer and spring 2005. To do this, we developed a bi-frequency acoustic method and extracted high-resolution information on the biomass and the patterns of distribution of crustacean macrozooplankton, fish and other marine compartments. We found that, although macrozooplankton comprises a number of distinct organisms, the euphausiids were the zooplankton group that better fitted the patterns from independent net sampling zooplankton data. Also, the similarities between the nocturnal patterns of size and biomass macrozooplankton distribution from this study and the known patterns of euphausiids, in particular Euphausia mucronata, suggest that euphausiids were the main constituent of the estimated nocturnal acoustic macrozooplankton biomass even if other organisms such as large copepods may have contributed considerably to the macrozooplankton biomass. The total macrozooplankton biomass was estimated to about 105 g m -2, i.e., two to five times more than previous estimates. This direct biomass estimation of macrozooplankton is in agreement with the new findings in trophic ecology indicating that forage fish consume mainly macrozooplankton. This high biomass also supports the current hypotheses explaining the NHCS high fish production. Using the method, we are able to revisit present-day and historical acoustic databases and extract high-resolution data on macrozooplankton, a key ecological compartment of the ecosystem. Since zooplankton is the link between the physically driven primary producers and the biologically driven tertiary consumers, this information

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

    USDA-ARS?s Scientific Manuscript database

    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...

  10. Comprehensive characterization of ethoxyquin transformation products in fish feed by traveling-wave ion mobility spectrometry coupled to quadrupole time-of-flight mass spectrometry.

    PubMed

    Negreira, Noelia; Regueiro, Jorge; Valdersnes, Stig; Berntssen, Marc H G; Ørnsrud, Robin

    2017-05-01

    Feed additives are typically used in intensive farming production over long periods, and hence, they can accumulate in farmed animal tissues. Concerns regarding the use of ethoxyquin as an antioxidant feed additive, have recently arisen due to its potential conversion into a series of transformation products (TPs). The aim of this work was to characterize the TPs of ethoxyquin in fish feed by a novel approach based on the use of traveling-wave ion mobility spectrometry (TWIMS) coupled to high-resolution quadrupole time-of-flight mass spectrometry (QTOFMS). First, ethoxyquin was oxidized under controlled conditions and the generated TPs were added to a comprehensive database. Atlantic salmon feeds were then screened for ethoxyquin TPs using both targeted and untargeted approaches. Twenty-seven TPs were tentatively identified during the oxidation experiments, fifteen of them also being present in the feed samples. In addition, ten other potential TPs were detected in fish feed following the untargeted approach. Thirty-one of these TPs have been reported for the first time in this work through the oxidation experiments and the feed samples. Therefore, this study provides valuable information on the oxidative fate of ethoxyquin in feed, which can be used for future evaluations of potential risk related to this additive.

  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. Regulation of feeding behavior and psychomotor activity by corticotropin-releasing hormone (CRH) in fish

    PubMed Central

    Matsuda, Kouhei

    2013-01-01

    Corticotropin-releasing hormone (CRH) is a hypothalamic neuropeptide belonging to a family of neuropeptides that includes urocortins, urotensin I, and sauvagine in vertebrates. CRH and urocortin act as anorexigenic factors for satiety regulation in fish. In a goldfish model, intracerebroventricular (ICV) administration of CRH has been shown to affect not only food intake, but also locomotor and psychomotor activities. In particular, CRH elicits anxiety-like behavior as an anxiogenic neuropeptide in goldfish, as is the case in rodents. This paper reviews current knowledge of CRH and its related peptides derived from studies of teleost fish, as representative non-mammals, focusing particularly on the role of the CRH system, and examines its significance from a comparative viewpoint. PMID:23754974

  13. 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

  14. 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

  15. Effects of fish oil feeding and fasting on LXRalpha/RXRalpha binding to LXRE in the SREBP-1c promoter in mouse liver.

    PubMed

    Nakatani, Teruyo; Katsumata, Aki; Miura, Shinji; Kamei, Yasutomi; Ezaki, Osamu

    2005-09-05

    High-fish oil feeding and fasting down-regulate sterol regulatory element-binding protein-1c (SREBP-1c) mRNA level and suppress lipogenesis in mouse liver. Previous promoter analysis revealed that liver X receptor alpha (LXRalpha)/retinoid X receptor alpha (RXRalpha) complex was required for SREBP-1c gene expression in cell culture. In in vitro studies, polyunsaturated fatty acids (PUFAs, n-6, n-3) inhibited binding of LXRalpha/RXRalpha heterodimer to LXR responsive elements (LXREs) in the SREBP-1c promoter. To examine whether fish oil feeding and fasting would also inhibit its binding to LXREs in mouse liver, active liver nuclear extracts were prepared by percoll gradient centrifugation, and gel mobility shift assay was conducted. Although 1- to 5-day fish oil feeding and 2-day fasting decreased SREBP-1c mRNA by 45-68% and 65%, respectively, fish oil feeding decreased binding of LXR/RXR heterodimer to LXREs by 0-26%, while 2-day fasting decreased their binding by 40-56%. Luciferase assay using mutation of LXREs in mouse primary hepatocytes revealed that the LXR ligand, T0901317, induced increased transcription of SREBP-1c mRNA was mediated by LXREs, but it is unknown whether fish oil/eicosapentaenoic acid (EPA)-induced down-regulation of SREBP-1c mRNA was mediated by LXREs. These data indicate that high-fish oil feeding might decrease SREBP-1c mRNA partly by decreased transcription of SREBP-1c, but if so, the binding inhibition of LXRalpha to LXREs might not be a major cause, while fasting decreased SREBP-1c mRNA, mainly by its binding inhibition of LXRalpha to LXREs in the SREBP-1c promoter.

  16. Trace element content of fish feed and bluegill sunfish (Lepomis macrochirus) from aquaculture and wild source in Missouri.

    PubMed

    Ikem, Abua; Egilla, Jonathan

    2008-09-15

    Trace element content of fish feed and bluegill sunfish muscles (Lepomis macrochirus) from aquaculture and natural pond in Missouri were determined using the inductively coupled-plasma optical emission spectrometer (ICP-OES) and the direct mercury analyzer (DMA). Dietary intake rates of trace elements were estimated. Dogfish muscle (DORM-2) and lobster hepatopancreas (TORT-2) reference standards were used in trace element recovery and method validations. The average elemental concentrations (mg/kg diet, dry wt.) of fish feed were: As 1.81, Cd 2.37, Co 0.10, Cr 1.42, Cu 8.0, Fe 404, Mn 35.9, Ni 0.51, Pb 9.16, Se 1.71, Sn 20.7, V 0.09, Zn 118 and Hg 0.07. The mean elemental concentrations (μg/kg wet wt.) in bluegill muscles from both aquaculture and wild (in parenthesis) sources were: As 0.36 (0.06), Cd 0.28 (0.01), Co 0.0 (0.0), Cr 0.52 (0.05), Cu 0.38 (0.18), Fe 17.5 (2.43), Mn 0.18 (0.24), Ni 0.18 (0.04), Pb 1.03 (0.04), Se 0.34 (0.30), Sn 0.66 (0.42), V 0.02 (0.01), Zn 6.97 (9.13) and Hg 0.06 (0.24). Kruskal-Wallis chi square indicated significant differences in As, Cd, Co, Cr, Cu, Fe, Ni, Pb, Sn, V, Zn and Hg (P<0.001), Se (P<0.01) and Mn (P<0.05) across the sampling locations. Dietary intake rates, estimated from weekly consumption of 228g of aquaculture and wild bluegills, posed no health risks for approximately 85% of all samples.

  17. Effect of marine protected areas (MPAs) on consumer diet: MPA fish feed higher in the food chain.

    PubMed

    Dell, Claire; Montoya, Joseph; Hay, Mark

    2015-11-26

    Marine Protected Areas (MPAs) are often established to mitigate the effects of overfishing and other human disturbances. In Fiji these are locally managed and, where enforced, have significantly higher coral cover, higher fish biomass, and lower seaweed cover than in the adjacent, unprotected reefs (non-MPAs). We investigated how the isotopic signatures of a common, mid-level consumer, Epinephelus merra, differed among three small (0.5- 0.8km(2)) MPAs versus adjacent, unprotected reefs. Isotopic ratios suggested that the fish in the MPAs fed higher in the food chain than those in the adjacent non-MPAs, despite being slightly smaller in size. Calculations using a brown alga as representative of the basal level of the food chain estimate this difference to be about half a trophic level. Thus, the isotopic ratio of a mid-level consumer can be noticeably altered over scales of only a few hundred meters. This may result from more complete food webs and hence greater prey choice and availability in the MPAs and implies that MPAs affect not only species' abundance and diversity, but also diet composition and trophic biology of member individuals. Our findings suggest E. merra exhibits considerable site fidelity in its feeding biology and thus provides a localized isotopic signal of its reef of residence. If the isotopic signal of this mid-level carnivore is reflective of the composition of the food web beneath it, the signal might provide an easily obtained indication of reef conditions in that area.

  18. Effect of marine protected areas (MPAs) on consumer diet: MPA fish feed higher in the food chain

    PubMed Central

    Dell, Claire; Montoya, Joseph; Hay, Mark

    2016-01-01

    Marine Protected Areas (MPAs) are often established to mitigate the effects of overfishing and other human disturbances. In Fiji these are locally managed and, where enforced, have significantly higher coral cover, higher fish biomass, and lower seaweed cover than in the adjacent, unprotected reefs (non-MPAs). We investigated how the isotopic signatures of a common, mid-level consumer, Epinephelus merra, differed among three small (0.5- 0.8km2) MPAs versus adjacent, unprotected reefs. Isotopic ratios suggested that the fish in the MPAs fed higher in the food chain than those in the adjacent non-MPAs, despite being slightly smaller in size. Calculations using a brown alga as representative of the basal level of the food chain estimate this difference to be about half a trophic level. Thus, the isotopic ratio of a mid-level consumer can be noticeably altered over scales of only a few hundred meters. This may result from more complete food webs and hence greater prey choice and availability in the MPAs and implies that MPAs affect not only species’ abundance and diversity, but also diet composition and trophic biology of member individuals. Our findings suggest E. merra exhibits considerable site fidelity in its feeding biology and thus provides a localized isotopic signal of its reef of residence. If the isotopic signal of this mid-level carnivore is reflective of the composition of the food web beneath it, the signal might provide an easily obtained indication of reef conditions in that area. PMID:27340314

  19. 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.

  20. Determination of melamine in milk powder, milk and fish feed by capillary electrophoresis: a good alternative to HPLC.

    PubMed

    Wen, Yingying; Liu, Huitao; Han, Ping; Gao, Yuan; Luan, Feng; Li, Xiuyong

    2010-10-01

    Since September 2008, an increased incidence of kidney stones and renal failure in infants, associated with the ingestion of infant formula contaminated with melamine has been reported in China. Furthermore, melamine was not only found in many protein-based food commodities, but also in the feeds for cattle and poultry. So it is necessary to develop a suitable method to determine melamine. A capillary zone electrophoresis (CZE) method for analysis of melamine was developed by use of running electrolyte containing 35 mmol L(-1) sodium dihydrogen phosphate at pH 3.5, with UV detection at 210 nm. Regression equation revealed linear relationships (r = 0.9999) between the peak-area and the content of melamine from 0.8 to 80 µg mL(-1). The detection limit was 0.08 µg mL(-1). The method was successfully applied to the determination of melamine in milk powder, milk and fish feed, with the recoveries from 94.5% to 103.7%. The performance of the CZE method evaluated in terms of precision, limits of detection, accuracy and quantification were comparable and in good agreement with those obtained by the HPLC method, with the advantage of shorter analysis time and lower cost. Copyright © 2010 Society of Chemical Industry.

  1. Comparing the effects of feeding a grain- or a fish meal-based diet on water quality, waste production, and rainbow trout Oncorhynchus mykiss performance within low exchange water recirculating aquaculture systems

    USDA-ARS?s Scientific Manuscript database

    Feeding a fish meal-free grain-based diet (GB) was compared to feeding a fish meal-based diet (FM) relative to water quality criteria, waste production, water treatment process performance, and rainbow trout Oncorhynchus mykiss performance within six replicated water recirculating aquaculture system...

  2. Does upwelling intensity influence feeding habits and trophic position of planktivorous fish?

    NASA Astrophysics Data System (ADS)

    Lopez-Lopez, Lucia; Preciado, Izaskun; Muñoz, Isabel; Decima, Moira; Molinero, Juan Carlos; Tel, Elena

    2017-04-01

    Food web configuration is shaped by many factors, including primary production patterns and oceanographic features, such as upwelling events. In this study, we investigate variability in the trophic position, food web interlinks and energy pathways of four planktivorous demersal fish in the Southern Bay of Biscay- NE Atlantic. The study area is exposed to upwelling events of varying intensity and shows a significant spatial gradient along the coast. The two sampling years were characterized by markedly different conditions, with weak summer upwelling in 2012 and an intense upwelling season in 2013. We used a complementary approach based on stomach content analysis (SCA) and stable isotope analysis (SIA) to test the effects of upwelling intensity and persistence on the food-web. In particular we investigated whether different intensities shift the main flow of energy between the pelagic and benthic energy pathways. We found conspicuous interannual changes in the isotopic POM, whose δ15N was 2.5‰ lower during the productive 2013 season. Interannual changes in the isotopic signature of the fish species were also detected, although their values did not mirror variability at the basal level. The SCA results did not match the isotopic changes, which likely reflected dietary adjustments of the species during summer. The upwelling intensity gradient along the coast did not affect the nitrogen isotopic ratio of any group, however there was a significant effect of such gradient on the carbon isotopic ratio of the fish and euphausiid species. This effect was likely related to the higher primary production associated with intense upwelling conditions.

  3. A two-step fermentation of distillers' grains using Trichoderma viride and Rhodopseudomonas palustris for fish feed.

    PubMed

    Zhang, Jian; Zhang, Wen-Xue; Li, Shun-Zhou; You, Ling; Zhang, Chao; Sun, Chuan-Ze; Liu, Xiao-Bin

    2013-10-01

    It is important to provide added value or to make full use of the co-product of grains from ethanol production. In order to convert distillers' grains into a high-quality feed, the Trichoderma viride and Rhodopseudomonas palustris fermentation were combined and investigated in this study. The T. viride fermentation was carried out in an aerobic fermentation installation in favoring of the growth of the fungi and the degradation of the cellulose, and then the fermentation of R. palustris was performed to increase the content of protein with an anaerobic installation. After the two step fermentations, the true protein content of dried distiller' grains increased from 11.4 to 33.6 % (w/w) (the content of crude protein from 14.5 to 39.7 %), the crude fiber content decreased from 21.3 to 7.6 % (w/w), the crude fat content increased from 5.5 to 7.9 % (w/w), the crude ash decreased from 14.6 to 10.2 % (w/w), the total phosphorus content increased from 0.4 to 1.2 % (w/w), and the water content was 11.8 % (w/w). The dried and fermented grains contain the R. palustris viable count of 5.3 × 10¹¹ CFU/g dry matter. The results may support a new application of an active photosynthetic bacteria fish feed in fisheries industry and offer a reference for the further study of lignocellulosic materials as raw materials converting into high-quality feed.

  4. 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

  5. Dietary high-linoleate safflower oil is not hypocholesterolemic in aged mice after a long-term feeding--comparison with lard, perilla oil and fish oil.

    PubMed

    Ishihara, A; Ito, A; Sakai, K; Watanabe, S; Kobayashi, T; Okuyama, H

    1995-04-01

    Aged mice (6 months of age) fed a conventional diet were shifted to diets containing 10% lard, high-linoleate safflower seed oil, high alpha-linolenate perilla seed oil or high-docosahexaenoate fish oil. A significant increase in whole body cholesterol (/g wt) was seen within 30 d after the shift (rapid response), followed by a gradual decrease in 60 to 120 d (slow response); similar changes occurred in all the dietary groups. Shortly after the shift, the serum cholesterol concentrations increased to higher levels in the lard and safflower oil groups than in the other groups, and the levels at 120 d were in the group order of safflower oil > lard > perilla oil > fish oil. Rapid and slow responses to dietary shifts were also seen in hepatic cholesterol levels (/g wt), which were higher in the lard group than in the other groups at 120 d. The arterial cholesterol contents of the fish oil group tended to be less than in the other groups at 120 d. Thus in aged mice after a relatively long-term feeding (> one tenth of the life-span), safflower oil was not hypocholesterolemic as compared with lard and other omega 3-rich oils. Long-term feeding of fish oil maintained serum cholesterol concentrations at lower levels than feeding with safflower oil or lard and without accumulating cholesterol in the aorta, liver or whole body; perilla oil was also hypocholesterolemic but to a lesser degree than fish oil.(ABSTRACT TRUNCATED AT 250 WORDS)

  6. Feeding ecology and trophic relationships of fish species in the lower Guadiana River Estuary and Castro Marim e Vila Real de Santo António Salt Marsh

    NASA Astrophysics Data System (ADS)

    Sá, Rita; Bexiga, Constança; Veiga, Pedro; Vieira, Lina; Erzini, Karim

    2006-10-01

    In this study we analyze the feeding ecology and trophic relationships of some of the main fish species (Soleidae, Moronidae, Mullidae, Sparidae, Mugilidae, and Batrachoididae) of the lower Estuary of the Guadiana River and the Castro Marim e Vila Real de Santo António Salt Marsh. We examined the stomachs of 1415 fish caught monthly between September 2000 and August 2001. Feeding indices and coefficients were determined and used along with the results of multivariate analysis to develop diagrams of trophic interactions (food webs). Results show that these species are largely opportunistic predators. The most important prey items are amphipods, gobies (Gobiidae), shrimps ( Palaemon serratus and Crangon crangon), and polychaete worms. The lower Estuary and associated salt marshes are important nurseries and feeding grounds for the species studied. In this area, it is therefore important to monitor the effects of changes in river runoff, nutrient input, and temperature that result from construction of the Alqueva Dam upstream.

  7. Determinations of hexabromocyclododecane (HBCD) isomers in channel catfish, crayfish, hen eggs and fish feeds from China by isotopic dilution LC-MS/MS.

    PubMed

    Hu, Xiaozhong; Hu, Decong; Song, Qi; Li, Jing; Wang, Peng

    2011-01-01

    HBCD is widely used brominated flame retardant, which is increasingly reported in the environment. A new isotopic dilution LC-MS/MS method was developed to determine three HBCD isomers, α-, β- and γ-HBCD in channel catfish, crayfish, hen eggs and fish feeds in this study, and especially for the first time HBCD isomers composition in crayfish, hen eggs and fish feeds. Soxhlet extractor and GPC cleanup were used, some important steps and crucial parameters were modified and intensified compared with other literatures, and LC and MS/MS conditions were optimized. The limits of quantitation values of 0.01, 0.005 and 0.005ngg(-1) wet weight in channel catfish and crayfish were calculated for three HBCD isomers, respectively; so did 0.1, 0.05 and 0.05ngg(-1) wet weight in eggs and 0.2, 0.1, 0.1ngg(-1) wet weight in fish feeds. Recoveries of α-HBCD, β-HBCD and γ-HBCD were ranged between 75% and 105% for these productions at medium and high-level spiked samples, and between 60% and 85% at low-level spiked samples. The established methods were therefore suitable for the determinations of three HBCD isomers in these productions at trace contamination levels. Moreover, thirty commercial channel catfish, crayfish, hen eggs and fish feeds samples collected from local markets, and thirty home-produced hen eggs from private owners in Hubei province of China, were analyzed to determine whether these productions were contaminated by HBCD. Using the established methods, HBCD emerged in 4 of 30 fish feeds and 3 of 30 home-produced eggs, and in low-ngg(-1) wet weight.

  8. Optimizing the closed suction surgical drainage system.

    PubMed

    Carruthers, Katherine H; Eisemann, Bradley S; Lamp, Susan; Kocak, Ergun

    2013-01-01

    Closed suction drains are indicated in a wide array of postoperative settings, with many distinct drainage systems available to the surgeon. The purpose of this study was to compare the suction gradients achieved using 2 different sizes of suction reservoirs and 2 different techniques for generating negative pressure. Drainage reservoirs of 100 and 400 ml were chosen to evaluate their ability to achieve suction. Suction was established in both sizes of drains by pressing the sides of the reservoir together or by pushing the bottom of the reservoir toward the top. Negative pressures were recorded with the reservoir empty, and after every 10-ml addition of saline. Averages were graphed to illustrate the applied suction over a range of drain volumes. The 100-ml drainage system reached a peak suction of -117.6 mmHg, while the 400-ml drainage system reached only a peak suction of -71.4 mmHg. Both of the maximum suction readings were achieved using the full-squeeze technique. The bottom-pushed-in technique did not result in any sustained measurable levels of suction using either of the reservoir volumes. Smaller drain reservoirs are more successful in generating a high initial suction than larger reservoirs, especially when the volume of fluid in the drain is relatively low. In all sizes of drains, compressing the sides of the reservoir is a far better technique for establishing negative pressure than pressing the bottom of the drain up toward the top.

  9. Effectiveness evaluation of different suction systems.

    PubMed

    Junevicius, Jonas; Surna, Algimantas; Surna, Rimas

    2005-01-01

    Microorganisms of the patient's oral cavity and his/her blood and saliva may cause different air-borne and blood-borne infectious diseases among odontologists and their assistants who work with patients. Quantitative analysis and spatial distribution analysis of the environmental spread of oral liquid and cooling liquid mixture were performed during this study. Effectiveness of suction systems of four types was evaluated: without suction, using a small-size suction pump alone, using a small-size and large-size suction pumps, using a small-size suction pump together with an experimental extra-oral aspirator. Quantitative changes of the water aerosol, which enters the environment during the preparation of teeth, were determined in respect of the used suction systems. The small-size pump system together with an experimental extra-oral suction system eliminated best the aerosol formed during the preparation.

  10. Feeding mechanism and functional morphology of the jaws of the lemon shark Negaprion brevirostris (Chondrichthyes, Carcharhinidae)

    PubMed

    Motta; Tricas; Summers

    1997-01-01

    This study tests the hypothesis that preparatory, expansive, compressive and recovery phases of biting behavior known for aquatically feeding anamniotes are conserved among extant elasmobranch fishes. The feeding mechanism of the lemon shark Negaprionbrevirostris is examined by anatomical dissection, electromyography and high-speed video analysis. Three types of feeding events are differentiated during feeding: (1) food ingestion primarily by ram feeding; (2) food manipulation; and (3) hydraulic transport of the food by suction. All feeding events are composed of the expansive, compressive and recovery phases common to aquatically feeding teleost fishes, salamanders and turtles. A preparatory phase is occasionally observed during ingestion bites, and there is no fast opening phase characteristic of some aquatically feeding vertebrates. During the compressive phase, palatoquadrate protrusion accounts for 26% of the gape distance during jaw closure and is concurrent with muscle activity in the dorsal and ventral preorbitalis and the levator palatoquadrati. Hydraulic transport events are shorter in duration than ram ingestion bites. Prey ingestion, manipulation and hydraulic transport events are all found to have a common series of kinematic and motor components. Individual sharks are capable of varying the duration and to a lesser extent the onset of muscle activity and, consequently, can vary their biting behavior. We propose a model for the feeding mechanism in carcharhinid sharks, including upper jaw protrusion. This study represents the first electromyographic and kinematic analysis of the feeding mechanism and behavior of an elasmobranch.

  11. 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.

  12. 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.

  13. The integration of locomotion and prey capture in divergent cottid fishes: functional disparity despite morphological similarity.

    PubMed

    Kane, Emily A; Higham, Timothy E

    2011-04-01

    Many mobile animals rely on the integration of locomotion and feeding to capture prey. Fishes commonly swim up to a prey item and utilize a combination of ram and suction feeding for prey capture. Marine cottids represent a diverse and abundant lineage of fishes that exhibit variation in feeding mode that is related to their mouth morphology. However, little is known regarding the integration of the locomotor and feeding systems during prey capture. We quantified the feeding kinematics, feeding performance and integration of locomotion and feeding in two species of divergent cottids: Blepsias cirrhosus (silver-spotted sculpin) and Oligocottus maculosus (tidepool sculpin). Individuals were caught from sympatric habitats near the Bamfield Marine Sciences Centre on Vancouver Island and filmed with a high-speed video camera (500 Hz) while feeding on amphipod prey. Two principal component axes summarize differences in integration and feeding mode despite similarity in attack velocity and feeding morphology (peak gape, peak cranial elevation and peak jaw protrusion). A greater number of correlations between locomotor and feeding variables in B. cirrhosus, compared with O. maculosus, indicate greater integration. We conclude that traditional measures of attack kinematics do not capture functionally and ecologically relevant differences between species. The mechanisms underlying differences in locomotor strategy likely result from unexplored morphological or ecological differences between species. In cottids, integration is apparent in more basal, subtidal species such as B. cirrhosus, and the need for integration may be superceded by demands from the habitat in more derived, shallow-water species such as O. maculosus.

  14. Vortex Lift Augmentation by Suction

    NASA Technical Reports Server (NTRS)

    Taylor, A. H.; Jackson, L. R.; Huffman, J. K.

    1983-01-01

    Lift performance is improved on a 60 degrees swept Gothic wing. Vortex lift at moderate to high angles of attack on highly swept wings used to improve takeoff performance and maneuverability. New design proposed in which suction of propulsion system augments vortex. Turbofan placed at down stream end of leading-edge vortex system induces vortex to flow into inlet which delays onset of vortex breakdown.

  15. Vortex Lift Augmentation by Suction

    NASA Technical Reports Server (NTRS)

    Taylor, A. H.; Jackson, L. R.; Huffman, J. K.

    1983-01-01

    Lift performance is improved on a 60 degrees swept Gothic wing. Vortex lift at moderate to high angles of attack on highly swept wings used to improve takeoff performance and maneuverability. New design proposed in which suction of propulsion system augments vortex. Turbofan placed at down stream end of leading-edge vortex system induces vortex to flow into inlet which delays onset of vortex breakdown.

  16. Hydrodynamic modelling of aquatic suction performance and intra-oral pressures: limitations for comparative studies

    PubMed Central

    Van Wassenbergh, Sam; Aerts, Peter; Herrel, Anthony

    2006-01-01

    The magnitude of sub-ambient pressure inside the bucco-pharyngeal cavity of aquatic animals is generally considered a valuable metric of suction feeding performance. However, these pressures do not provide a direct indication of the effect of the suction act on the movement of the prey item. Especially when comparing suction performance of animals with differences in the shape of the expanding bucco-pharyngeal cavity, the link between speed of expansion, water velocity, force exerted on the prey and intra-oral pressure remains obscure. By using mathematical models of the heads of catfishes, a morphologically diverse group of aquatic suction feeders, these relationships were tested. The kinematics of these models were fine-tuned to transport a given prey towards the mouth in the same way. Next, the calculated pressures inside these models were compared. The results show that no simple relationship exists between the amount of generated sub-ambient pressure and the force exerted on the prey during suction feeding, unless animals of the same species are compared. Therefore, for evaluating suction performance in aquatic animals in future studies, the focus should be on the flow velocities in front of the mouth, for which a direct relationship exists with the hydrodynamic force exerted on prey. PMID:16849247

  17. 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

  18. 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

  19. Projecting mechanics into morphospace: disparity in the feeding system of labrid fishes.

    PubMed Central

    Hulsey, C Darrin; Wainwright, Peter C

    2002-01-01

    In no group of organisms has the link between species richness, morphological disparity, disparity in mechanics and functional or ecological diversification been made explicit. As a step towards integrating these measures of diversity, we examine how the mechanics of the anterior-jaw four-bar linkages of 104 species of Great Barrier Reef (GBR) labrid fishes maps into a scale-independent morphospace. As predicted from theory, no relationship exists between overall size and the mechanics of velocity and force transmission in labrid anterior-jaw linkages. Nonetheless, mechanics associated with the anterior jaw appear to have constrained diversification of labrid anterior-jaw morphology. Furthermore, simulations depict a generally nonlinear relationship between the length of individual links and transmission of motion. In addition, no relationship was found between morphological disparity and mechanical disparity among the most species-rich labrid groups from the GBR. It is also established that regions of morphospace equivalent in morphological disparity differ over nearly an order of magnitude in mechanical disparity. These results illustrate that without an explicit interpretation of the consequences of per unit change in morphology, conclusions about diversification drawn only from morphological disparity may be misleading. PMID:11839201

  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.

  1. 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. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. 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 salmonids 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.

  3. Molecular characterization, tissue distribution and feeding related changes of NUCB2A/nesfatin-1 in Ya-fish (Schizothorax prenanti).

    PubMed

    Lin, Fangjun; Zhou, Chaowei; Chen, Hu; Wu, Hongwei; Xin, Zhiming; Liu, Ju; Gao, Yundi; Yuan, Dengyue; Wang, Tao; Wei, Rongbin; Chen, Defang; Yang, Shiyong; Wang, Yan; Pu, Yundan; Li, Zhiqiong

    2014-02-25

    The protein nucleobindin-2 (NUCB2) was identified over a decade ago and recently raised great interest as its derived peptide nesfatin-1 was shown to reduce food intake and body weight in rodents. However, the involvement of NUCB2 in feeding behavior has not well been studied in fish. In the present study, we characterized the structure, distribution, and meal responsive of NUCB2A/nesfatin-1 in Ya-fish (Schizothorax prenanti) for the first time. The full length cDNA of Ya-fish was 2140base pair (bp), which encoded a polypeptide of 487 amino acid residues including a 23 amino acid signal peptide. A high conservation in NUCB2 sequences was found in vertebrates, however the proposed propeptide cleavage site (Arg-Arg) conserved among other species is not present in Ya-fish NUCB2A sequence. Tissue distribution analysis revealed that Ya-fish NUCB2A mRNA was ubiquitously expressed in all test tissues, and abundant expression was detected in several regions including the hypothalamus, hepatopancreas, ovary and intestines. NUCB2A mRNA expression respond to feeding status change may vary and be tissue specific. NUCB2A mRNA levels significantly increased (P<0.05) in the hypothalamus and intestines after feeding and substantially decreased (P<0.01) during a week food deprivation in the hypothalamus. Meanwhile, NUCB2A mRNA in the hepatopancreas was significantly elevated (P<0.001) during food deprivation, and a similar increase was also found after short-time fasting. This points toward a potential hepatopancreas specific local role for NUCB2A in the regulation of metabolism during food deprivation. Collectively, these results provide the molecular and functional evidence to support potential anorectic and metabolic roles for NUCB2A in Ya-fish.

  4. [The feeding ecology of the endemic fish Girardinichthys multiradiatus (Cyprinidontiformes: Goodeidae) in Lagunas of Zempoala National Park, Mexico].

    PubMed

    Trujillo-Jiménez, Patricia; Monteros Viveros, Efrén Espinosa de los

    2006-12-01

    Girardinichthys multiradiatus, locally known as "mexcalpique", is a small endemic fish of the Lerma river basin. Its presence in lakes (Zempoala) suggests a long-standing connection between these lakes and the river basin. The current range of this species in the Mexico and Toluca valley appears to have been reduced, making this park a refuge for the species. Nevertheless, little is known about its biology. We studied its diet and feeding habits in Acoyotongo Lake, Lagunas de Zempoala National Park (19 degrees 01'30"-19 degrees 06' N, 99 degrees 16'20"-99 degrees 21' W) where seasonal collections were carried out. The gut contents of 97 specimens were identified to the most specific taxonomic category possible and analyzed with numeric and frequency of occurrence methods. The general diet of this species consists of twelve dietary components, eleven of which are of animal origin. Hymenopterans, springtails and chironomids represented the highest percentage of ingestion and preference. G. multiradiatus is as a carnivorous species with entomophagous tendencies.

  5. Feeding habits of the deep-sea fish, Scopelogadus beanii (Pisces: Melamphaide), in the western North Atlantic

    NASA Astrophysics Data System (ADS)

    Gartner, John V.; Musick, John A.

    1989-10-01

    Stomach contents were examined from 106 specimens (37-113 mm SL) of the melamphaid Scopelogadus beanii collected from the slope waters of the western North Atlantic Ocean by bottom and midwater trawls. Seventy-five stomachs (70.8%) contained food. Gelatinous zooplankton (mainly salps) and associated obligate and facultative symbiotic hyperiid amphipods of the genera Vibilia, Parathemisto, and Phronima were the predominant food items in the stomachs of S. beanii, although calanoid copepods (especially Paraeuchaeta norvegica) were of similar importance in individuals from offshore midwater trawls. Other pelagic prey items included halocyprid ostracods, euphausiids and fishes. Representatives from three benthic groups (gammaridean amphipods, polychaetes and pelecypods) were recovered from stomachs of specimens from bottom trawls. The only significant pattern observed in diel feeding periodicity was a decrease in the percentage of stomachs containing food between 1201 and 1800 h as compared to the percentage of stomachs containing food between 1201 and 2400 h. This observation might be an artifact, however, because no differences in degree of prey digestion were observed. Limited seasonal data from bottom-trawled collections indicate that consumption of amphipods was highest in spring, whereas that of gelatinous plankton was highest in summer and autumn. There were no apparent ontogenetic shifts in diet composition. Differences in prey importance between bottom and pelagic trawl-captured individuals may be due to vertical ranges and abundance of prey taxa and the presence of S. beanii near the bottom in continental slope waters.

  6. 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.

  7. 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

  8. Pilot study on control of phytoplankton by zooplankton coupling with filter-feeding fish in surface water.

    PubMed

    Ma, Hua; Cui, Fuyi; Liu, Zhiquan; Fan, Zhenqiang

    2009-01-01

    A pilot-scale facility was originally designed to control phytoplankton in algae-laden reservoir water characterized by summer cyanobacteria blooms (mainly Microcystis flos-aquae). The system made good use of the different food habits of Daphnia magna and silver carp. Zooplankton (Daphnia magna), filter-feeding fish (silver carp), and zooplankton (Daphnia magna) were stocked in three separated tanks in sequence, respectively. Thus, single-cell phytoplankton and some Microcystis flos-aquae in small size were first grazed by Daphnia magna in the first tank, and in the second tank phytoplankton larger than 10 microm were filtered by silver carp, and the concentration of the remaining phytoplankton was further reduced to a rather low level by Daphnia magna in the third tank. The results showed that the system had good removal efficiencies of phytoplankton and chlorophyll a, 86.85% and 59.41%, respectively, and permanganate consumption (COD(Mn)) and turbidity were lowered as well. A high phytoplankton removal efficiency and low cost indicated that the system had a good advantage in pre-treating algae-laden source water in drinking water works.

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

    PubMed

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

    2015-01-22

    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.

  10. 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.

  11. Method for maintaining precise suction strip porosities

    NASA Technical Reports Server (NTRS)

    Gallimore, Frank H. (Inventor)

    1989-01-01

    This invention relates to a masking method generally and, more particularly to a method of masking perforated titanium sheets having laminar control suction strips. As illustrated in the drawings, a nonaerodynamic surface of a perforated sheet has alternating suction strip areas and bonding land areas. Suction strip tapes overlie the bonding land areas during application of a masking material to an upper surface of the suction strip tapes. Prior to bonding the perforated sheet to a composite structure, the bonding land tapes are removed. The entire opposite aerodynamic surface is masked with tape before bonding. This invention provides a precise control of suction strip porosities by ensuring that no chemicals penetrate the suction strip areas during bonding.

  12. 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. © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.

  13. Appropriate suction device in rescue medicine.

    PubMed

    Dahlgren, B E; Nilsson, H; Bjorn, P; Skedevik, C

    1987-12-01

    In rescue medicine, a suction apparatus must function in a variety of environmental conditions. To find an appropriate device for the Swedish Air Force air rescue service the Laerdal suction device 790,000 was selected for further testing according to international standards for aviation safety. Tests showed that vibrations had deleterious effects on the internal construction of the suction device. In addition, an electromagnetic field was generated affecting the navigation, autopilot, and communication systems. We conclude that the suction apparatus and probably other devices as well must be tested for their functioning in adverse environments and their ability to meet international aviation safety regulations.

  14. 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.

  15. PCDD/F and DL-PCB levels in meat from broilers and rabbits fed with fish-oil enriched feeds.

    PubMed

    Abalos, Manuela; Parera, Jordi; Rivera, Josep; Abad, Esteban

    2010-01-01

    The aim of this study was to assess the effect on the final levels of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs) in meat when fats, in particular fish oils, are included as ingredients in feeds. Two types of animals (broilers and rabbits) were fed with three different experimental feeds containing varying amounts of two selected fish oils. PCDD/Fs and DL-PCBs were determined in the fish oils, the feeds and in the animals' meat. For broilers, PCDD/F and DL-PCB profiles in meat samples were similar to those found in the corresponding feeds, even though bioaccumulation of the highest chlorinated PCDD/F congeners seemed to decrease. Depending on the treatment, PCDD/F and the sum of PCDD/F and DL-PCB levels were 1.11-4.60 and 6.03-16.71 pg WHO-TEQ/g fat, respectively. For most of the cases, these values exceeded the maximum established by the Commission Regulation (EC) No. 1881/2006. In contrast, the levels of these contaminants in the corresponding feeds ranged from 0.11 to 0.54 pg WHO-TEQ/g, in the case of PCDD/Fs, and from 0.59 to 1.75 pg WHO-TEQ/g, when DL-PCBs were also included. These levels were, in general, below the maximum allowed by the Commission Directive 2006/13/EC. The results of the experiments with rabbits were not as conclusive as those for broilers although bioaccumulation appeared to be slower.

  16. 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

  17. Evolutionary Novelty versus Exaptation: Oral Kinematics in Feeding versus Climbing in the Waterfall-Climbing Hawaiian Goby Sicyopterus stimpsoni

    PubMed Central

    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

  18. 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

  19. Long-term management of a dog with idiopathic megaesophagus and recurrent aspiration pneumonia by use of an indwelling esophagostomy tube for suction of esophageal content and esophagogastric tube feeding.

    PubMed

    Kanemoto, Yuka; Fukushima, Kenjiro; Kanemoto, Hideyuki; Ohno, Koichi; Tsujimoto, Hajime

    2017-01-24

    A 10-year-old neutered male Labrador Retriever dog was diagnosed with idiopathic megaesophagus. Despite receiving conventional treatments including elevated feeding, the dog showed repeated regurgitation and aspiration pneumonia, consequently developing weight loss and severe malnutrition. For the purpose of controlling regurgitation, an esophagostomy tube was placed for draining the esophageal fluid. Additionally, an esophagogastric tube was placed for nutritional support. After tube placement, the average frequency of regurgitation was reduced from 2.4 times a day to 0.1 times a day. The nutritional state of the dog improved gradually, and the body weight increased from 18.5 to 27.9 kg. The dog died on day 951, and necropsy revealed a gastric ulcer (2.5 cm in diameter), presumably esophagostomy tube-induced injury. This case report suggests that patients with idiopathic megaesophagus and persistent regurgitation might benefit from esophageal drainage through an esophagostomy tube.

  20. Long-term management of a dog with idiopathic megaesophagus and recurrent aspiration pneumonia by use of an indwelling esophagostomy tube for suction of esophageal content and esophagogastric tube feeding

    PubMed Central

    KANEMOTO, Yuka; FUKUSHIMA, Kenjiro; KANEMOTO, Hideyuki; OHNO, Koichi; TSUJIMOTO, Hajime

    2016-01-01

    A 10-year-old neutered male Labrador Retriever dog was diagnosed with idiopathic megaesophagus. Despite receiving conventional treatments including elevated feeding, the dog showed repeated regurgitation and aspiration pneumonia, consequently developing weight loss and severe malnutrition. For the purpose of controlling regurgitation, an esophagostomy tube was placed for draining the esophageal fluid. Additionally, an esophagogastric tube was placed for nutritional support. After tube placement, the average frequency of regurgitation was reduced from 2.4 times a day to 0.1 times a day. The nutritional state of the dog improved gradually, and the body weight increased from 18.5 to 27.9 kg. The dog died on day 951, and necropsy revealed a gastric ulcer (2.5 cm in diameter), presumably esophagostomy tube-induced injury. This case report suggests that patients with idiopathic megaesophagus and persistent regurgitation might benefit from esophageal drainage through an esophagostomy tube. PMID:27853047

  1. 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.

  2. Functional morphology of feeding in the scale-eating specialist Catoprion mento.

    PubMed

    Janovetz, Jeff

    2005-12-01

    The wimple piranha, Catoprion mento, has a narrow-range natural diet with fish scales comprising an important proportion of its total food intake. Scales are eaten throughout most of ontogeny and adults feed almost exclusively on this food source. Catoprion exhibits a novel prey capture behavior when removing scales for ingestion. Scale feeding strikes involve a high-speed, open-mouth, ramming attack where the prey is bitten to remove scales and the force of the collision knocks scales free. Unique kinematic parameters of scale-feeding strikes include a mean gape angle of nearly 120 degrees and a ;plateau' stage of prolonged maximum displacement for cranial elevation and opercular expansion. When feeding on live fish or loose scales, Catoprion performs a typical ram/suction attack that is modulated according to the elusiveness of the prey. Captures of elusive fish elicit faster strikes with greater displacement of cranial elements than do attacks on loose scales sinking in the water column. Despite its specialized diet and suite of anatomical characters, functional versatility in feeding behavior has not been reduced in Catoprion, as predicted by many analogous studies in functional morphology. On the contrary, the behavioral repertoire of Catoprion has been broadened by the addition of a novel behavior for scale feeding.

  3. Monola oil versus canola oil as a fish oil replacer in rainbow trout feeds: effects on growth, fatty acid metabolism and final eating quality.

    PubMed

    Turchini, G M; Moretti, V M; Hermon, K; Caprino, F; Busetto, M L; Bellagamba, F; Rankin, T; Keast, R S J; Francis, D S

    2013-11-15

    Monola oil, a high oleic acid canola cultivar, and canola oil were evaluated as replacers of fish oil at three levels of inclusion (60%, 75% and 90%) in rainbow trout diets. After a 27-week grow-out cycle, the diet-induced effects on growth, fatty acid metabolism and final eating quality were assessed. Overall, no effects were noted for growth, feed utilisation or fish biometry, and the fatty acid composition of fish fillets mirrored that of the diets. Dietary treatments affected fillet lipid oxidation (free malondialdehyde), pigmentation and flavour volatile compounds, but only minor effects on sensorial attributes were detected. Ultimately, both oils were demonstrated to possess, to differing extents, suitable qualities to adequately replace fish oil from the perspective of fish performance and final product quality. However, further research is required to alleviate on-going issues associated with the loss of health promoting attributes (n-3 long chain polyunsaturated fatty acids) of final farmed products. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. 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.

  5. Estimating soil suction from electrical resistivity

    NASA Astrophysics Data System (ADS)

    Piegari, E.; Di Maio, R.

    2013-09-01

    Soil suction and resistivity strongly depend on the degree of soil saturation and, therefore, both are used for estimating water content variations. The main difference between them is that soil suction is measured using tensiometers, which give point information, while resistivity is obtained by tomography surveys, which provide distributions of resistivity values in large volumes, although with less accuracy. In this paper, we have related soil suction to electrical resistivity with the aim of obtaining information about soil suction changes in large volumes, and not only for small areas around soil suction probes. We derived analytical relationships between soil matric suction and electrical resistivity by combining the empirical laws of van Genuchten and Archie. The obtained relationships were used to evaluate maps of soil suction values in different ashy layers originating in the explosive activity of the Mt Somma-Vesuvius volcano (southern Italy). Our findings provided a further example of the high potential of geophysical methods in contributing to more effective monitoring of soil stress conditions; this is of primary importance in areas where rainfall-induced landslides occur periodically.

  6. 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. Copyright © 2011 Wiley-Liss, Inc.

  7. 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... Devices § 880.5740 Suction snakebite kit. (a) Identification. A suction snakebite kit is a device consisting of a knife, suction device, and tourniquet used for first-aid treatment of snakebites by removing...

  8. Effects of size on predation risk, behavioural response to fish, and cost of reduced feeding in larval Ischnura verticalis (Coenagrionidae: Odonata).

    PubMed

    Dixon, S M; Baker, R L

    1988-07-01

    We used laboratory studies to examine the role of predation risk and cost of anti-predator behaviour in determining the behavioural response of several larval instars of Ischnura verticalis to a fish predator (Lepomis gibbosus). Smaller larvae were less susceptible to fish predation than larger larvae. Smaller larvae depressed movement to a greater degree in the presence of fish than did larger larvae; large larvae were generally less active than small larvae regardless of fish presence. Reduced feeding resulted in smaller larvae suffering more in terms of reduced growth than did large larvae. In general, our results tend to support the hypothesis that individuals that suffer high costs of anti-predator behaviour but little risk of predation may only exhibit anti-predator behaviours in the presence of predators, whereas individuals with a higher risk of predation and a lower cost of anti-predator behaviour may evolve anti-predator mechanisms that are in effect even in the absence of predators.

  9. 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

    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.

  10. 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

  11. Efficient atraumatic liquid suction by means of slit suction tubes combined with a pressure control unit.

    PubMed

    Vällfors, B

    1984-01-01

    In 1976 a modified suction system for neurosurgery and precision surgery was presented. It was developed to meet the need for efficient and atraumatic liquid suction. the system consists of suction tube ends provided with three vertical slits in the suction edge (W-tubes), a Pressure Control Unit (PCU) and an independent suction pump with an air capacity of 25-30 litres per min. This system has subsequently been modified for microsurgery. The PCU normally controls the negative pressure to 20 kPa (corresponding to 200 cm of water) for atraumatic suction of liquid, which is needed during most of the operating time. For suction of various tissues or cleaning the system, the surgeon can set the pressure limit to 50 or 90 kPa by means of a foot-operated IR-transmitter in a pedal with a kick-down function. The PCU and the W-tubes, which neutralize the pressure load on tissue and the sudden interruption of liquid flow that are inevitable with conventional suction tips, form a system with a high liquid suction capacity in spite of the atraumatic suction pressure. This is possible because the slits maintain a large active suction area. Crushed or soft tissues and coagulated blood are aspirated as and when required, if necessary by elevation of the negative pressure limit. The W-tubes are not provided with an air inlet hole on the tube because that method of pressure control proved unpredictable and variable and reduced the suction capacity by interfering with the flow.(ABSTRACT TRUNCATED AT 250 WORDS)

  12. 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. © 2014 The Fisheries Society of the British Isles.

  13. 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.

  14. Fish meal replacement by plant protein substitution and guar gum addition in trout feed. Part II: Effects on faeces stability and rheology.

    PubMed

    Brinker, Alexander; Friedrich, Christian

    2012-01-01

    In the explosively growing aquaculture industry, the challenge of sustainability includes a requirement to produce more fish than are consumed by stock. A promising avenue of research is the substitution of the fish meal in feeds with plant protein. However, there are inherent risks in the development of such feeds, and serious consideration should be given not only to nutritional content, but also to the mechanical quality of resulting faecal wastes. The present study uses a plate on plate rheometer running in different flow modes (creep, oscillation) to assess the rheological properties of wastes resulting from different diets.All faeces were shown to be thixotropic in nature, independent of diet composition. Details of dietary composition influence the consistency and the characteristic stresses at which faecal structure changes from a viscoelastic solid into a viscoelastic liquid. Furthermore, in linking active food components with mechanical properties of chyme faeces, rheological studies may be used to understand and counteract some problematic properties. Substituting 100% of fish meal with plant proteins leads to faeces that rapidly disintegrate into very fine solids which threaten the viability of aquacultural operations. Adding just 0.3% of the rapidly hydrating non-starch polysaccharide, guar gum (GG), significantly increased the viscosity and elastic modulus of the faeces. These mechanical improvements increase the size of the resulting particles and the effectiveness with which they can be removed, thereby leading to optimized water quality. GG addition was sufficiently effective to counter the stability and particle size effects of a 50% substitution of fish meal, but could not mitigate those of a 100% substitution, wherein dissolution effects of an unknown emulsifier are suspected.

  15. Development of a low-cost technology for mass production of the free-living nematode Panagrellus redivivus as an alternative live food for first feeding fish larvae.

    PubMed

    Ricci, M; Fifi, A P; Ragni, A; Schlechtriem, C; Focken, U

    2003-01-01

    The free-living nematode Panagrellus redivivus is a suitable food source for first feeding fish. In the present report, a new method for the mass production of P. redivivus is presented. The technique involves multiplication of the nematode in monoxenic (single microorganism: Saccharomyces cerevisiae) solid culture (fluid media supported by 1- to 4-cm(3) sponge cubes) in autoclavable plastic bags (size range: 50 x 30 cm to 75 x 67 cm). Two growing media were tested: oat-meal medium (OM), which is an oat-based medium (16.7% oat-meal flour in 0.8% saline solution), and purified ingredient medium (PIM), a semi-synthetic medium (1.64% meat peptone, 0.94% yeast extract, 12.6% corn starch, 0.24% glucose, 1.48% sunflower oil, in 0.8% saline solution). The bags were inoculated with 350 nematodes/g medium. After an average period of 12 days (11-13 days) at 25 degrees C, the average yield (number of nematodes/g medium) was 241 x 10(3) for OM and 333 x 10(3) for PIM in 12-l bags (50 x 30 cm). The production scale has currently reached a bag volume of 50 l (75 x 67 cm); using PIM and the conditions described above, it was possible to harvest more than 1.3 x 10(9) nematodes/bag (291 x 10(3) nematodes/g medium). In PIM, when sun flower oil was replaced with the same amount of fish oil or cod liver oil, yields of 259 x 10(3) and 290 x 10(3) nematodes/g medium, respectively, were attained. The technology for mass production and formulation of P. redivivus should enable fish-hatchery operators to rely on a cheap, standardised, and permanently available live food product for first feeding fish larvae.

  16. Distribution and feeding of Benthosema glaciale in the western Labrador Sea: Fish-zooplankton interaction and the consequence to calanoid copepod populations

    NASA Astrophysics Data System (ADS)

    Pepin, Pierre

    2013-05-01

    This study evaluated the distribution of major calanoid copepods in the western Labrador Sea in relation to that of the myctophid Benthosema glaciale, and investigated patterns of prey composition and feeding periodicity by the latter to assess the potential impact of mesopelagic fish on copepod populations that reside in the deep ocean. Hydroacoustic surveys indicated that B. glaciale and the deep-scattering layer are widely distributed throughout the region with limited evidence of patchiness, with an average abundance of 6 fish m-2 and biomass of 9.3 g m-2. There was clear evidence of diurnal variations in feeding activity that was achieved through vertical migration from several hundred meters depths to the surface layer. B. glaciale fed principally on calanoid copepods, with prey size dependent on the length of the fish but the relative variability in prey size was independent of predator length. Average rations were generally less than 1% of body weight per day, and the patterns of diurnal vertical migration by myctophids suggest that individuals fed once every two days rather than daily. The estimated mortality caused by B. glaciale on the calanoid populations, which considers most sources of uncertainty, ranged from 0.002 to 1.8% d-1, with the mid-point of these estimates being ˜0.15% d-1, which is well below the estimated mortality rates of 10-20% d-1 based on vertical life tables. From observations from this and other ecosystems, understanding and contrasting the drivers of population dynamics and productivity of calanoid copepods in different deep basins of the North Atlantic will likely require a more comprehensive characterization of the plankton and pelagic and oceanic fish faunas of the epipelagic and mesopelagic zones and their trophic relationships and interactions.

  17. 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.

  18. Effects of feeding roasted safflower seeds (variety IL-111) and fish oil on dry matter intake, performance and milk fatty acid profiles in dairy cattle.

    PubMed

    Alizadeh, A R; Alikhani, M; Ghorbani, G R; Rahmani, H R; Rashidi, L; Loor, J J

    2012-06-01

    Safflower seed has the highest concentration of linoleic acid among 80 oilseeds but little information exists on the effective use of SS for lactation cows. It was hypothesised that a diet supplemented with an Iranian SS variety (IL-111) in combination with fish oil (FO) would result in higher concentrations of trans-18:1 (including vaccenic acid) and conjugated linoleic acids in milk fat than feeding an unsupplemented control diet. Our objective was to determine the effects of feeding diets containing: (i) (C); (ii) 25 g of roasted SS IL-111 (RSS); (iii) 20 g FO and (iv) 25 g RSS + 10 g FO (RSS + FO) per kilogram of dietary DM on feed intake, ruminal fermentation, milk production and fatty acid profile. Eight multiparous Holstein cows were used in a replicated 4 × 4 Latin square design study. The experiment had four periods of 21 days. Milk Fat percentage was lower (p < 0.01) with FO supplementation and averaged 19.0 and 21.5 g/kg milk with FO and RSS + FO compared with 30.3 and 32.5 g/kg with C and RSS. Feed intake also was lower (p < 0.01) with FO vs. C (23.1 vs. 24.5 kg/day) but feeding RSS resulted in greater feed intake compared with other treatments (26 kg/day). Despite lower feed intake with FO, milk production did not change from controls but feeding RSS + FO resulted in greater milk yield than controls (42.6 vs. 39.3 kg/day). Ruminal pH was greater (p < 0.01) in cows fed FO than other treatments. Supplemental FO alone or in combination with RSS resulted in dramatic increases (p < 0.01) in c9,t11-18:2 in milk fat (12.7 and 13.2 g/day vs. 5.8 and 7.02 with C and RSS). It was surprising to note that 25 g/kg RSS can improve feed intake. © 2011 Blackwell Verlag GmbH.

  19. Evaluation of three portable suction devices.

    PubMed

    Simon, E J; Davidson, J A; Boom, S J

    1993-09-01

    Three portable suction devices were evaluated and compared with a wall-mounted vacuum driven suction unit. The Repro-med Res-Q-Vac, the Dräger Sujector 2000 and the Laerdal suction unit were assessed by measuring the time taken to aspirate 140 ml of mock gastric contents. The respective times for each device, expressed as mean and (range) were 7.39 (4.3-10.4), 8.6 (7.8-9.4) and 11.4 (9.4-12.6) s. These compare favourable with the Ohmeda suction unit (7.27 (6.2-8.9)). Each type of device has advantages and disadvantages when factors such as size, power supply and portability are considered, and each will be the most suitable for a particular situation.

  20. Assuring Precise LFC-Suction-Strip Porosities

    NASA Technical Reports Server (NTRS)

    Gallimore, Frank H.

    1988-01-01

    Masking technique in bonding perforated titanium sheets to substructures. Technique to obtain precise control of widths of perforated titanium suction strips. Precision required for successful laminar-flow control, (LFC) in flight environments.

  1. [Characterization of the intestinal digestive glycosidases in plankton- and benthos-feeding species of the fish genus Ballerus (Cyprinidae)].

    PubMed

    Golovanova, I L; Filippov, A A; Bolotovskiĭ, A A; Levin, B A

    2015-01-01

    The activity of hydrolases (maltase, saccharase, amylolytic activity) in the intestinal mucosa of the plankton-feeding zope Ballerus ballerus and the benthos-feeding white-eye bream Ballerus sapa was investigated. The temperature characteristics of maltase hydrolysis (T(opt) and E(act)) are similar in both species. The lower K(m) of maltase hydrolysis in the white-eye bream reflects a higher enzyme/substrate affinity and indicates a more effective carbohydrate hydrolysis in the benthos-versus plankton-feeding species. The glycosidase activity in the white-eye bream is twice as high as in the zope. This may be due not only to different feeding spectra and biochemical food contents but also to the differences in thyroid status of species under consideration.

  2. 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.

  3. Automated detection of feeding strikes by larval fish using continuous high-speed digital video: a novel method to extract quantitative data from fast, sparse kinematic events.

    PubMed

    Shamur, Eyal; Zilka, Miri; Hassner, Tal; China, Victor; Liberzon, Alex; Holzman, Roi

    2016-06-01

    Using videography to extract quantitative data on animal movement and kinematics constitutes a major tool in biomechanics and behavioral ecology. Advanced recording technologies now enable acquisition of long video sequences encompassing sparse and unpredictable events. Although such events may be ecologically important, analysis of sparse data can be extremely time-consuming and potentially biased; data quality is often strongly dependent on the training level of the observer and subject to contamination by observer-dependent biases. These constraints often limit our ability to study animal performance and fitness. Using long videos of foraging fish larvae, we provide a framework for the automated detection of prey acquisition strikes, a behavior that is infrequent yet critical for larval survival. We compared the performance of four video descriptors and their combinations against manually identified feeding events. For our data, the best single descriptor provided a classification accuracy of 77-95% and detection accuracy of 88-98%, depending on fish species and size. Using a combination of descriptors improved the accuracy of classification by ∼2%, but did not improve detection accuracy. Our results indicate that the effort required by an expert to manually label videos can be greatly reduced to examining only the potential feeding detections in order to filter false detections. Thus, using automated descriptors reduces the amount of manual work needed to identify events of interest from weeks to hours, enabling the assembly of an unbiased large dataset of ecologically relevant behaviors.

  4. 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.

  5. Exposing Northern shrimp (Pandalus borealis) to fish feed containing the antiparasitic drug diflubenzuron caused high mortality during molting.

    PubMed

    Bechmann, Renée Katrin; Lyng, Emily; Berry, Mark; Kringstad, Alfhild; Westerlund, Stig

    2017-09-06

    Use of the chitin synthesis inhibitor diflubenzuron (DFB) as an antiparasitic drug in salmon aquaculture raises concern over its impact on marine ecosystems. Further, global drivers, such as ocean warming and acidification (OAW), may increase the toxicity of hazardous substances including DFB. The aim of the present study was to examine the combined effects of DFB-medicated salmon feed on ovigerous Northern shrimp (Pandalus borealis) under Control (pHNBS 8.0, 7.0ºC) and OAW conditions (pHNBS 7.6, 9.5ºC). DFB-exposed shrimp consumed on average 0.1-0.3 g medicated feed during the 2-week exposure period, and high mortality (61-73%) was documented at both environmental conditions. There was no significant interaction between OAW and DFB. Only 2-7% of DFB-exposed shrimp molted successfully compared to 65% in Control and 63% in OAW. The shrimp molted earlier (shorter intermolt period) and exhibited higher feeding rate at OAW compared to Control conditions. An additional experiment, where female shrimp were exposed to DFB closer to molting, noted increased mortality after only 4 d exposure, and successful molting for some shrimp after 2 to 3 weeks of depuration. High mortality of shrimp exposed to DFB-medicated feed indicates that the use of this feed in aquaculture could affect local shrimp populations.

  6. Exposure to the cyanotoxin microcystin arising from interspecific differences in feeding habits among fish and shellfish in the James River Estuary, Virginia.

    PubMed

    Wood, Joseph D; Franklin, Rima B; Garman, Greg; McIninch, Stephen; Porter, Aaron J; Bukaveckas, Paul A

    2014-05-06

    The cyanotoxin, microcystin (MC), is known to accumulate in the tissues of diverse aquatic biota although factors influencing exposure, such as feeding habits and seasonal patterns in toxin production, are poorly known. We analyzed seasonal variation in the MC content of primary and secondary consumers, and used dietary analysis (gut contents and stable isotopes) to improve understanding of cyanotoxin transport in food webs. Periods of elevated toxin concentration were associated with peaks in the abundance of genes specific to Microcystis and MC toxin production (mcyD). Peak toxin levels in consumer tissues coincided with peak MC concentrations in seston. However, toxins in tissues persisted in overwintering populations suggesting that potential health impacts may not be limited to bloom periods. Interspecific differences in tissue MC concentrations were related to feeding habits and organic matter sources as pelagic fishes ingested a greater proportion of algae in their diet, which resulted in greater MC content in liver and muscle tissues. Sediments contained a greater proportion of allochthonous (terrestrial) organic matter and lower concentrations of MC, resulting in lower toxin concentrations among benthic detritivores. Among shellfish, the benthic suspension feeder Rangia cuneata (wedge clam) showed seasonal avoidance of toxin ingestion due to low feeding rates during periods of elevated MC. Among predators, adult Blue Catfish had low MC concentrations, whereas Blue Crabs exhibited high levels of MC in both muscle and viscera.

  7. 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.

  8. 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.

  9. 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.

  10. Atraumatic suction tip for microneurosurgery--clinical experience.

    PubMed

    Mariak, Z; Lyson, T

    2007-12-01

    Our two-year experience with a new atraumatic tip for the neurosurgical suction tube is described. During microneurosurgical procedures the tip reduces injury to fragile vital brain structures and protects them from being aspirated into the suction tube. The perforated membrane of the appended suction tip does not impede evacuation of blood in any situation and can be easily cleaned off without demounting. The device can be immediately attached to the tube and disconnected. The neurosurgeon need not concentrate on its use, in contrast to those systems with active suction pressure control. The atraumatic suction tip is available in several sizes to fit different callibers of suction tubes.

  11. Feeding ecology and ontogenic diet shifts of juvenile fish species in an inverse estuary: The Sine-Saloum, Senegal

    NASA Astrophysics Data System (ADS)

    Gning, Ndombour; Vidy, Guy; Thiaw, Omar Thiom

    2008-01-01

    We examined the diet of juvenile fish of four species - Eucinostomus melanopterus (Gerreidae), Ethmalosa fimbriata (Clupeidae), Monodactylus sebae (Monodactylidae), and Sarotherodon melanotheron (Cichlidae) - between their appearance on the nursery ground and the end of the recruitment season, when they began to shift to deeper parts of the estuary. Fish were collected from the Sine-Saloum, an inverse estuary in Senegal, West Africa. Sampling was conducted at six sites located along the salinity gradient. The study was conducted in the context of an inverse estuary where increasing salinity leads to the disappearance of mangroves. Stomach contents were sorted and the preferred prey determined to the lowest possible taxonomic level. Ontogenic changes in diet were characterized and results expressed as the frequency of occurrence of the prey. The results showed that almost all juveniles began with a "classical" zooplanktonic diet. Following that first stage, they then preyed on items belonging to the periphytic community in the vicinity of mangroves (when present). Juvenile Ethmalosa fimbriata, a phytoplankton feeder as an adult, displayed that kind of transitory diet, a finding not previously recorded. Plant material (algae and leaves) occurred frequently in the stomach contents. All four species began the ontogenic shift toward their adult diet at a length of 50 mm. The periphytic community supported on mangrove prop roots contributes to the diet of juvenile fish living in proximity to mangroves; this may not be verified for those fish living in open waters.

  12. 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. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  13. 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.

  14. 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...

  15. 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...

  16. 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...

  17. 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...

  18. 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.

  19. Mechanical suction for clot evacuation: experience with "suction bridge" for safe and effective clot removal.

    PubMed

    Goel, Apul; Dalela, Diwakar

    2015-05-01

    To present the experience with the use of a "suction bridge" for removal of bladder clots. In all patients presenting with bladder clots, mechanical suction was done using a "suction bridge". This bridge has a luer lock that is fixed to the cystoscope sheath, and the other end is connected to suction tube. The suction pressure was started at 250 mmHg and was increased up to 400 mmHg if needed. Twenty patients with a mean age of 59.4 years were included. The etiologies of bladder clots included bladder tumor in nine, benign prostate hyperplasia (BPH) in two, BPH with bladder stone in one, hematochyluria in three, and post-transurethral prostate resection in 10. Eighteen patients presented in clot retention. The estimated clot size ranged from 50 mL to more than 1 L. The mean duration for clot removal was 15 min (range 5-60). The procedure was successful in all patients. There was no bladder injury. The limitations include the small number of recruits, the non-randomized nature of study, and no control group for comparison. Mechanical suction is another safe, fast, and effective option of clot removal from the urinary bladder. The suction bridge is useful while using this method.

  20. Suction evacuation of hemothorax: A prospective study.

    PubMed

    Savage, Stephanie A; Cibulas, George A; Ward, Tyler A; Davis, Corinne A; Croce, Martin A; Zarzaur, Ben L

    2016-07-01

    Although tube thoracostomy is a common procedure after thoracic trauma, incomplete evacuation of fluid places the patient at risk for retained hemothorax. As little as 300 to 500 cm of blood may result in the need for an additional thoracostomy tube or, in more severe cases, lung entrapment and empyema. We hypothesized that suction evacuation of the thoracic cavity before tube placement would decrease the incidence of late complications. Patients requiring tube thoracostomy within 96 hours of admission were prospectively identified and underwent suction evacuation of the pleural space (SEPS) before tube placement. These patients were compared to historical controls without suction evacuation. Demographics, admission vital signs, laboratory values, details of chest tube placement, and outcomes were collected on all patients. Multivariable logistic regression was used to compare outcomes between groups. A total of 199 patients were identified, consisting of 100 retrospective controls and 99 SEPS patients. There were no differences in age, sex, admission injury severity score or chest abbreviated injury score, admission laboratory values or vital signs, or hospital length of stay. Mean (SD) volume of hemothorax in SEPS patients was 220 (297) cm; with only 48% having a volume greater than 100 cm at the time of tube placement. Three patients developed empyema, and 19 demonstrated retained blood; there was no difference between SEPS and control patients. Suction evacuation of the pleural space was significantly protective against recurrent pneumothorax after chest tube removal (odds ratio, 0.332; 95% confidence interval, 0.148-0.745). Preemptive suction evacuation of the thoracic cavity did not have a significant impact on subsequent development of retained hemothorax or empyema. Suction evacuation of the pleural space significantly decreased incidence of recurrent pneumothorax after thoracostomy removal. Although the mechanism is unclear, such a benefit may make this

  1. Remotely operated submersible underwater suction apparatus

    DOEpatents

    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.

  2. Transport suction apparatus and absorption materials evaluation

    NASA Technical Reports Server (NTRS)

    Krupa, Debra T.; Gosbee, John

    1991-01-01

    The specific objectives were as follows. The effectiveness and function was evaluated of the hand held, manually powered v-vac for suction during microgravity. The function was evaluated of the battery powered laerdal suction unit in microgravity. The two units in control of various types of simulated bodily fluids were compared. Various types of tubing and attachments were evaluated which are required to control the collection of bodily fluids during transport. Various materials were evaluated for absorption of simulated bodily fluids. And potential problems were identified for waste management and containment of secretions and fluids during transport. Test procedures, results, and conclusions are briefly discussed.

  3. 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.

  4. Molecular epidemiology of Salmonella spp. isolates from gulls, fish-meal factories, feed factories, animals and humans in Norway based on pulsed-field gel electrophoresis.

    PubMed Central

    Nesse, L. L.; Refsum, T.; Heir, E.; Nordby, K.; Vardund, T.; Holstad, G.

    2005-01-01

    The molecular epidemiology of 98 isolates of Salmonella serovar Agona (n = 27), S. Montevideo (n = 42) and S. Senftenberg (n = 29) from wild-living gulls, fish-meal factories, feed factories, humans and domestic animals was investigated using pulsed-field gel electrophoresis (PFGE) and computerized numerical analysis. Two of the S. Agona profiles were identified both in gulls and in two of the factories. In addition, one of these profiles was detected in two infected poultry farms. Two of the S. Montevideo profiles were also identified both in gulls and in two of the factories, and one of these profiles was observed in a human isolate. Four factories shared an identical S. Senftenberg profile. The S. Senftenberg profile found in gulls was not identified in any other source investigated. The presence of isolates with identical PFGE profiles indicates potential epidemiological links between different factories, as well as between gulls and factories. PMID:15724711

  5. 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

  6. 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.

  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. 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 menstrual...

  9. 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 menstrual...

  10. 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 menstrual...

  11. 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 menstrual...

  12. Analysis of hepatic vitamins A1, A2, their fatty acyl esters, and vitamin E for biomonitoring mammals feeding on freshwater fish.

    PubMed

    Käkelä, Anne; Käkelä, Reijo; Hyvärinen, Heikki

    2002-02-01

    In tissues of freshwater fish-feeding mammals, 3,4-didehydroretinol (A2) is a major form of vitamin A. In mink liver, with organochlorine exposure, this analog has been found to decrease more than retinol (A1) and thus has potential as a sensitive freshwater biomarker. The presence of the analogs A1 and A2 as alcohol and different fatty acyl esters, which react to polychlorinated biphenyls differently, necessitates detailed analyses achieved by using direct extraction of tissue homogenate. In direct hexane extraction, compared to total levels of the vitamins obtained in the saponification procedure, a large proportion of the vitamins was released only after repeated and long-time vortex mixing with the extraction solvent. Thus, in tissue extraction, the use of internal standardization alone can lead to a rough underestimation of the levels of these fat-soluble vitamins. For analyses of vitamins A1 and A2 in liver, we applied the argentation high-performance liquid chromatography, which provided good separation of individual A1 and A2 fatty acyl esters. We report retention times for numerous esters of A1 and A2 and, to aid identification, the change in their retention properties after adding AgNO3 to the mobile phase. The argentation did not affect the recoveries of any forms of the retinoids studied but destroyed half the vitamin E. Despite selective acylation of fatty acids into the vitamin A esters, the fatty acids of the esters were the same as those found to be the major fatty acids in the gas-liquid chromatography of total lipids. The goal of this work was to create a methodology that is suitable for biomonitoring alcoholic and esterified vitamins A1 and A2 in tissues of freshwater fish-feeding mammals.

  13. Use of Suction Piles for Mooring of Mobile Offshore Bases.

    DTIC Science & Technology

    1998-06-11

    ANNUAL PERFORMANCE REPORT Title: Use of Suction Piles for Mooring of Mobile Offshore Bases (ONR Grant No. N00014-97-1-0887) Period: June...Literature Review The literature study on suction piles has been completed and the final report has been submitted to the Naval Facilities Engineering...Analytical Performance Study of Suction Piles The suction pile performance study using linear elastic soil material properties has been completed. Results

  14. 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...

  15. 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...

  16. 21 CFR 868.6810 - Tracheobronchial suction catheter.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Tracheobronchial suction catheter. 868.6810... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Miscellaneous § 868.6810 Tracheobronchial suction catheter. (a) Identification. A tracheobronchial suction catheter is a device used to aspirate liquids or...

  17. 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....4430 Cardiopulmonary bypass intracardiac suction control. (a) Identification. A cardiopulmonary bypass intracardiac suction control is a device which provides the vacuum and control for a cardiotomy return sucker...

  18. 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...

  19. 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...

  20. Reversed flow above a plate with suction

    NASA Technical Reports Server (NTRS)

    Lin, S. P.; Tobak, M.

    1986-01-01

    A minor extension is developed for Kovasznay's (1948) solution, and an exact solution is presented for Navier-Stokes equations that may represent the reversed flow about a flat plate with suction. This exact solution is the result of a search for a solution that may serve as an exact basic flow for a model stability analysis of nonparallel flows involving flow reversal.

  1. Genetic and morphological population differentiation in the rock-dwelling and specialized shrimp-feeding cichlid fish species Altolamprologus compressiceps from Lake Tanganyika, East Africa.

    PubMed

    Spreitzer, Maria Luise; Mautner, Selma; Makasa, Lawrence; Sturmbauer, Christian

    With about 250 endemic species, Lake Tanganyika contains an extraordinarily diverse cichlid fish fauna, and thus represents an ideal model system for the study of pathways and processes of speciation. The Lamprologini form the most species-rich tribe in Lake Tanganyika comprising about 100 species in seven genera, most of which are endemic to the lake. They are territorial substrate-breeders and represent a monophyletic tribe. By combined analysis of population genetics and geometric morphometric markers, we assessed gene flow among three populations of the highly specialized shrimp-feeding rock-dweller Altolamprologus compressiceps, separated by geographic distance and ecological barriers. Five highly polymorphic microsatellite markers were analyzed in conjunction with 17 landmarks in order to compare genetic differences to body shape differences among populations. Both genetic and morphological analyses revealed significant differentiation among the three studied populations. A significant, but overall relatively low degree of genetic differentiation supports a very recent divergence. Phenotypic differentiation was primarily found in the head region of A. compressiceps. In agreement with findings in other cichlid species, similar adaptations to specialized feeding mechanisms can consequently lead to marginal shape changes in the trophic apparatus.

  2. Food composition and feeding habits of some fresh water fishes in various water systems at Abbassa, Egypt, with special reference to snails transmitting diseases.

    PubMed

    El Gamal, Abd El-Rahman A; Ismail, Nahed M M

    2005-08-01

    Study of feeding habits of freshwater fishes collected from ponds at World Fish Center (ICLARM) showed that the African catfish, Clarias gariepinus and Forskal catfish, Bagras bayad had the highest proportion of full stomachs (31-58% & 44-45% respectively). In cichlid fishes, the rate of full stomachs was much lower, being 0.0-12.5% and showed higher incidence of empty stomachs that varied from 37.5% for Oreochromis niloticus to 78.3% for Sarotherodon galilaeus. Food items were analyzed by the percentage of point assessment (P%), abundance (N%) and frequency of occurrence (F%). Results of the three methods of analyses (Index of relative importance, I.R.I) emphasized the importance of plants (1214.7) as a major food resource in the stomach of Nile tilapia, O. niloticus followed by shell fragments (628.5), whereas, snail soft bodies were the main food category in the diet of hybrid tilapia O. niloticus x O. aureus (2539.3). Shell fragments (652) and snail soft bodies (296.9) were the 1st in relative importance as foods of O. aurea. In case of S. galillae, shell fragments (338) came 2nd in I.R.I. after plants (559). Present investigation shows that shell fragments were represented by 11.1% and 15.1% in the diet of African catfish, C. gariepinus by (N%) and (P%) methods, however, they came as the second food item in its diet by I.R.I (1237.3). According to F% method, both shell fragments and Crustacea were present in the diet of C. gariepinus considerable proportions each of 47.4%. Shell fragments were represented by low proportions in the diet of B. bayad 3.9, 2.1 and 22.2 by N%, P% and F% respectively.

  3. 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

    USDA-ARS?s Scientific Manuscript database

    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...

  4. 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

    USDA-ARS?s Scientific Manuscript database

    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....

  5. 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

    Weinberger, Joel; Klaper, Rebecca

    2014-06-01

    Pharmaceuticals and personal care products (PPCPs) 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 the 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

  6. 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

  7. Effects of feeding fish meal and n-3 fatty acids on milk yield and metabolic responses in early lactating dairy cows.

    PubMed

    Moussavi, A R Heravi; Gilbert, R O; Overton, T R; Bauman, D E; Butler, W R

    2007-01-01

    The study was designed to test the effects of feeding fish meal (FM) and specific n-3 fatty acids on milk yield and composition, dry matter intake, plasma concentrations of metabolic hormones and metabolites, and liver triglyceride accumulation in early lactating cows. From 5 to 50 d in milk (DIM), cows were fed diets that were isonitrogenous, isoenergetic, and isolipidic containing none (control), 1.25, 2.5, or 5% menhaden FM or 2.3% Ca salts of fish oil fatty acids (CaFOFA). Milk yield (48.2, 49.8, 48.6, 53.5, and 52.2 +/- 1.0 kg/d, respectively) and dry matter intake (22.7, 22.8, 23.0, 23.8, and 24.7 +/- 0.5 kg/d, respectively) differed among diets. Average daily plasma glucose concentration (53.4, 55.3, 51.1, 57.6, and 57.3 +/- 1.3 mg/dL, respectively) was also affected by diet, and plasma insulin concentration was increased by 5% FM and 2.3% Ca-FOFA. At 25 and 50 DIM, blood was collected before feeding and hourly for 11 h after feeding. Plasma glucose concentrations in cows during the day were similar among diets at 25 DIM, but differed at 50 DIM (54.6, 54.4, 52.4, 60.5, and 58.3 +/- 1.4 mg/dL for 0, 1.25, 2.5, and 5% FM or 2.3% CaFOFA, respectively). Plasma insulin was increased in cows fed 5% FM and 2.3% CaFOFA at 25 DIM and was similar among diets at 50 DIM. Dietary treatments had no significant effect on milk composition, energy balance, or on daily plasma concentrations of nonesterified fatty acids, beta-hydroxybutyrate, and urea. Plasma aspartate aminotransferase and hepatic triglyceride concentration in cows did not differ among diets at 21 DIM. Results from this experiment demonstrate that dietary supplementation with FM or n-3 polyunsaturated fatty acids in early lactating dairy cows significantly increased milk yield and DMI with no change in milk composition.

  8. 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.

  9. Feeding of predaceous fishes on out-migrating juvenile-salmonids in John Day Reservoir, Columbia River

    USGS Publications Warehouse

    Poe, Thomas P.; Hansel, Hal C.; Vigg, S.; Palmer, D.E.; Prendergast, L.A.

    1991-01-01

    Diets of northern squawfish Ptychocheilus oregonensis, smallmouth bass Micropterus dolomieu, walleye Stizostedion vitreum, and channel catfish Ictalurus punctatus from John Day Reservoir were examined to determine the extent of predation on juvenile salmonids during seaward migrations of the salmonids during April–August 1983–1986. Juvenile Pacific salmon Oncorhynchus spp. and steelhead O. mykiss were the most important food group (by weight) of northern squawfish – about 67% – but made up smaller proportions of the food of the other predators: channel catfish, 33%; walleyes, 14%; smallmouth bass, 4%. Seasonal changes in diets indicated that northern squawfish preferred juvenile salmonids in May and August (generally the peak period of salmonid out-migration), and switched to prickly sculpin Cottus asper when numbers of juvenile salmonids declined; walleyes and smallmouth bass showed a preference only for prickly sculpin among the prey fishes analyzed. As judged by dietary composition and prey selectivity, the northern squawfish was the major fish predator on juvenile salmonids in the reservoir; channel catfish also were important predators in the upper reservoir in spring. Walleyes and smallmouth bass were much less important predators on salmonids, and appeared to select subyearling chinook salmon only in August when the distribution of this prey overlapped with that of the predators. Size-selective predation by northern squawfish may also play an important role in reducing survival of the smaller individuals within each run of out-migrating juvenile salmonids.

  10. Does feeding behavior facilitate trophic niche partitioning in two sympatric sucker species from the American Southwest?

    PubMed

    O'Neill, Matthew W; Gibb, Alice C

    2014-01-01

    We examined two sympatric desert fishes, Sonora suckers (Catostomus insignis) and desert suckers (Pantosteus clarkii), and asked, does feeding behavior facilitate trophic niche partitioning? To answer this question, we conducted laboratory-based feeding trials to determine whether morphology alone facilitates the diet separation between the relatively unspecialized, omnivorous Sonora sucker and the more morphologically specialized, algivorous desert sucker or whether behavioral differences accompany morphological specialization. We predicted that (1) algivorous desert suckers would maximize contact between jaws and substrate and produce a large mouth-gape to facilitate scraping attached food-material; (2) omnivorous Sonora suckers would be more effective suction feeders when consuming unattached food items from the benthos; and (3) because they are anatomically specialized for scraping, desert suckers could not alter their feeding behavior when presented with different prey types, whereas relatively unspecialized Sonora suckers could vary behavior with prey type. We found that both species maximized jaw contact when feeding on benthic-attached food, although desert suckers produced a greater gape area. We also found that Sonora suckers were more effective suction feeders when feeding on benthic-unattached prey. Counter to our initial predictions, both species altered key aspects of feeding behavior in response to different prey types/locations. It appears that both sucker species can function as generalist feeders to exploit a variety of prey types within their natural habitat; indeed, this behavioral versatility may allow desert and Sonora suckers to respond to the cyclic environmental changes that are characteristic of the aquatic habitats of the American Southwest.

  11. 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

  12. Experimental findings from zero-tank net positive suction head operation of the J-2 hydrogen pump

    NASA Technical Reports Server (NTRS)

    Stinson, H. P.; Strickland, R. J.

    1972-01-01

    The results of a series of liquid hydrogen turbopump tests to demonstrate the feasibility of zero-tank net positive suction head are presented. A J-2 engine hydrogen pump and S-IVB stage fuel feed system were used for this investigation. The pump was operated at flows and speeds equivalent to normal J-2 engine operating conditions and at hydrogen bulk temperatures between 39 and 45 R. These tests show zero-tank not positive suction head to be a realistic operating mode that should be considered for future applications.

  13. 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. Copyright 2008 Wiley-Liss, Inc.

  14. Practical success of biomanipulation using filter-feeding Fish to control cyanobacteria blooms: a synthesis of decades of research and application in a subtropical hypereutrophic lake.

    PubMed

    Xie, P; Liu, J

    2001-08-08

    Lake Donghu is a 32-km2 shallow, subtropical lake near the Yangtze River (P.R. China) that has experienced dramatic changes in the past five decades. These changes include: (1) a trophic state change from mesotrophy to hypertrophy; (2) dense blooms of cyanobacteria during every summer from the 1970s to 1984; (3) a cessation of blooms starting in 1985, with no recurrence; and (4) an increase, coincident with bloom declines, in the production of silver and bighead carp (filter-feeders) by more than tenfold. There are several possible explanations for the disappearance of blooms, including changes in nutrient concentrations, increased zooplankton grazing, and increased grazing on algae by fish. The long-term data suggest that changes in nutrients or in zooplankton were not important, but that the remarkably increased fish densities might have played the key role. To test this hypothesis, in situ enclosure experiments were conducted in three years. The main conclusions are as follows: (1) an increased stocking of the lake with carp played a decisive role in the elimination of cyanobacteria blooms; (2) both silver and bighead carp can eliminate cyanobacteria blooms directly by grazing; (3) zooplankton cannot suppress the blooms; and (4) the lake still is vulnerable to the outbreak of blooms, should fish grazing decline. The critical biomass of carp is approximately 50 g m3. The results suggest the applicability of a new food-web manipulation (increased stocking with filter-feeding fish) for controlling cyanobacteria blooms in hypereutrophic lakes. The approach differs from traditional biomanipulation in Europe and North America, where piscivores are added to control planktivores, and this in turn increases zooplankton and decreases algae. The new biomanipulation method is being used or being tested to counteract cyanobacteria blooms in many Chinese lakes such as Lake Dianchi in Yunnan Province, Lake Chaohu in Anhui Province, and Lake Taihu in Jiangsu Province. The

  15. 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.

  16. Effects of oxidised dietary fish oil and high-dose vitamin E supplementation on growth performance, feed utilisation and antioxidant defence enzyme activities of juvenile large yellow croaker (Larmichthys crocea).

    PubMed

    Wang, Jun; Xu, Houguo; Zuo, Rantao; Mai, Kangsen; Xu, Wei; Ai, Qinghui

    2016-05-01

    This study was conducted to elucidate the effects of oxidised dietary lipids and high-dose vitamin E (VE) on growth performance and immune responses of large yellow croaker. Juvenile fish (initial average body weight of 7·82 (sem 0·68) g) were fed diets containing either fresh fish oil (fresh diet, peroxide value (POV)=1·72 mEq/kg) or fish oil oxidised to varying degrees (oxidised diets, POV=28·29-104·21 mEq/kg), with or without supplementary 600 mg VE/kg diet, for 10 weeks in floating cages. Growth was significantly lower and feed intake (g/100 g body weight per d) was higher in fish fed the oxidised diet. Supplementation with VE increased the growth of fish fed the oxidised diets, but significantly decreased the growth of fish fed the fresh diet. Hepatosomatic index increased with increasing dietary POV and decreased with VE supplementation. Hepatic catalase activity, superoxide dismutase (SOD) activity and malondialdehyde content were significantly higher in fish fed the oxidised diets, and these values decreased significantly following VE supplementation. However, hepatic SOD activity was enhanced by VE supplementation in fish fed the fresh diet. Air-exposure mortality was significantly increased by dietary POV, and this effect was inhibited by VE supplementation. These results suggest that dietary oxidised fish oil could stimulate the activities of antioxidant defence enzymes in stressed large yellow croaker. High-dose VE supplementation can alleviate oxidative stress of large yellow croaker fed oxidised fish oil, but can exert deleterious effects on fish in the absence of oxidative stress.

  17. PADDLEFISH BUCCAL FLOW VELOCITY DURING RAM SUSPENSION FEEDING AND RAM VENTILATION

    PubMed

    Cech; Cheer

    1994-01-01

    A micro-thermistor probe was inserted into the buccal cavity of freely swimming paddlefish to measure flow velocity during ram ventilation, ram suspension feeding and prey processing. Swimming speed was measured from videotapes recorded simultaneously with the buccal flow velocity measurements. Both swimming velocity and buccal flow velocity were significantly higher during suspension feeding than during ram ventilation. As the paddlefish shifted from ventilation to feeding, buccal flow velocity increased to approximately 60 % of the swimming velocity. During prey processing, buccal flow velocity was significantly higher than the swimming velocity, indicating that prey processing involves the generation of suction. The Reynolds number (Re) for flow at the level of the paddlefish gill rakers during feeding is about 30, an order of magnitude lower than the Re calculated previously for pump suspension-feeding blackfish. These data, combined with data available from the literature, indicate that the gill rakers of ram suspension-feeding teleost fishes may operate at a substantially lower Re than the rakers of pump suspension feeders.

  18. Aerodynamic control using forebody blowing and suction

    NASA Technical Reports Server (NTRS)

    Ng, T. Terry; Malcolm, Gerald N.

    1991-01-01

    Aerodynamic control using pneumatic forebody flow control was studied. Three methods of control were investigated: (1) blowing from a localized jet, (2) blowing from a slot, and (3) surface suction. Flow visualization and yawing moment measurements were performed on F/A-18 models in a water tunnel. The results show that all the methods were effective in controlling the forebody flow over a wide range of angles of attack and sideslip. The advantages and limitations of each of the control methods were discussed. The experiments suggested that all the control methods work basically on the principle of separation control. Based on the results of the water tunnel tests, the blowing or suction mass flow requirements appear to be within the limits of typical engine-bleed available from a modern fighter engine.

  19. 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.

  20. Heterospecific aggression and dominance in a guild of coral-feeding fishes: the roles of dietary ecology and phylogeny.

    PubMed

    Blowes, Shane A; Pratchett, Morgan S; Connolly, Sean R

    2013-08-01

    Interspecific competition mediates biodiversity maintenance and is an important selective pressure for evolution. Competition is often conceptualized as being exploitative (indirect) or involving direct interference. However, most empirical studies are phenomenological, focusing on quantifying effects of density manipulations, and most competition theory has characterized exploitation competition systems. The effects on resource use of traits associated with direct, interference competition has received far less attention. Here we examine the relationships of dietary ecology and phylogeny to heterospecific aggression in a guild of corallivorous reef fishes. We find that, among chaetodontids (butterflyfishes), heterospecific aggression depends on a synergistic interaction of dietary overlap and specialization: aggression increases with dietary overlap for interactions between specialists but not for interactions involving generalists. Moreover, behavioral dominance is a monotonically increasing function of dietary specialization. The strong, positive relationship of dominance to specialization suggests that heterospecific aggression may contribute to the maintenance of biodiversity where it promotes resource partitioning. Additionally, we find strong phylogenetic signals in dietary overlap and specialization but not behavioral dominance. Our results support the use of phylogeny as a proxy for ecological similarity among butterflyfishes, but we find that direct measures of dietary overlap and specialization predict heterospecific agression much better than phylogeny.

  1. 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.

  2. [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.

  3. Atypical feeding behavior of Long-tailed Ducks in the wake of a commercial fishing boat while clamming

    USGS Publications Warehouse

    Perry, Matthew; Osenton, Peter C.; White, Timothy P.

    2017-01-01

    A foraging group of Clangula hyemalis (Long-tailed Duck) was observed on 10 February 2010 diving behind a commercial boat that was clamming near Monomoy Island, Nantucket Sound, MA. We used a shotgun to collect 9 of the ducks, and our analyses of gizzard and gullet (esophagus and proventriculus) revealed 37 food items in the gizzard and 16 in the gullet. Mollusca were the dominant food in the gizzard (49%), whereas Crustacea were dominant in the gullet (57%). Crustacea were the second most important food in the gizzard (38%), whereas Mollusca were the second most important food in the gullet (31%). Relatively high volumes of the Amphipoda Caprella sp. (skeleton shrimp) and the Decopoda Crangon septemspinosa (Sand Shrimp) were recorded in the gullet and gizzard. Ensis directus (Atlantic Jackknife Clam) formed the greatest volume of Mollusca in the gizzard (15%) and in the gullet (15%). Long-tailed Ducks had fed on this Bivalvia and several other species of Mollusca that had no shell or broken shell when consumed. Many of the food organisms were apparently dislodged and some damaged by the clamming operation creating an opportunistic feeding strategy for the Long-tailed Ducks.

  4. 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.

  5. 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.

  6. Feeding healthy beagles medium-chain triglycerides, fish oil, and carnitine offsets age-related changes in serum fatty acids and carnitine metabolites.

    PubMed

    Hall, Jean A; Jewell, Dennis E

    2012-01-01

    The purpose of this study was to determine if feeding dogs medium-chain triglycerides (MCT), fish oil, and L-carnitine enriched foods offsets age-associated changes in serum fatty acids (FA) and carnitine metabolites. Forty-one healthy Beagles, mean age 9.9 years (range 3.1 to 14.8), were fed control or one of two treatment foods for 6 months. All foods were complete and balanced and met the nutrient requirements for adult dogs, and had similar concentrations of moisture, protein, and fat (approx. 7.4%, 14.0%, and 18.1%, respectively). The treatment diets both contained added L-carnitine (300 mg/kg) and 0.6% (treatment food 1) or 1.5% (treatment food 2) added fish oil. Treatment food 2 also had increased MCT from coconut oil, added corn oil, and reduced animal fat. Composition of serum FA was determined by gas chromatography of FA methyl esters. Metabolomic profiles of serum samples were determined from extracted supernatants that were split and run on GC/MS and LC/MS/MS platforms, for identification and relative quantification of small metabolites. Body composition was determined by dual energy x-ray absorptiometry. Among dog groups, there was no change in total-lean-body weight, or in serum total protein and serum albumin concentrations, based on time or dietary treatment. Serum concentrations of carnitine metabolites were decreased in geriatric (>7 years) vs. mature adult (≤ 7 years) dogs, and supplementation with L-carnitine attenuated the effects of aging. The ratio of PUFA to SFA was significantly greater in mature dogs at baseline (P ≤ 0.05). Serum concentrations of eicosapentaenoic and docosahexaenoic FA increased in a dose-dependent manner. Dogs consuming treatment food 2 also had increased serum concentrations of lauric and myristic FA, and decreased concentrations of SFA, MUFA, and arachidonate (all P ≤ 0.05) and their PUFA to SFA ratio increased. In summary, dietary MCT, fish oil, and L-carnitine counterbalanced the effects of aging on circulating

  7. Feeding Healthy Beagles Medium-Chain Triglycerides, Fish Oil, and Carnitine Offsets Age-Related Changes in Serum Fatty Acids and Carnitine Metabolites

    PubMed Central

    Hall, Jean A.; Jewell, Dennis E.

    2012-01-01

    The purpose of this study was to determine if feeding dogs medium-chain triglycerides (MCT), fish oil, and L-carnitine enriched foods offsets age-associated changes in serum fatty acids (FA) and carnitine metabolites. Forty-one healthy Beagles, mean age 9.9 years (range 3.1 to 14.8), were fed control or one of two treatment foods for 6 months. All foods were complete and balanced and met the nutrient requirements for adult dogs, and had similar concentrations of moisture, protein, and fat (approx. 7.4%, 14.0%, and 18.1%, respectively). The treatment diets both contained added L-carnitine (300 mg/kg) and 0.6% (treatment food 1) or 1.5% (treatment food 2) added fish oil. Treatment food 2 also had increased MCT from coconut oil, added corn oil, and reduced animal fat. Composition of serum FA was determined by gas chromatography of FA methyl esters. Metabolomic profiles of serum samples were determined from extracted supernatants that were split and run on GC/MS and LC/MS/MS platforms, for identification and relative quantification of small metabolites. Body composition was determined by dual energy x-ray absorptiometry. Among dog groups, there was no change in total-lean-body weight, or in serum total protein and serum albumin concentrations, based on time or dietary treatment. Serum concentrations of carnitine metabolites were decreased in geriatric (>7 years) vs. mature adult (≤7 years) dogs, and supplementation with L-carnitine attenuated the effects of aging. The ratio of PUFA to SFA was significantly greater in mature dogs at baseline (P≤0.05). Serum concentrations of eicosapentaenoic and docosahexaenoic FA increased in a dose-dependent manner. Dogs consuming treatment food 2 also had increased serum concentrations of lauric and myristic FA, and decreased concentrations of SFA, MUFA, and arachidonate (all P≤0.05) and their PUFA to SFA ratio increased. In summary, dietary MCT, fish oil, and L-carnitine counterbalanced the effects of aging on circulating

  8. Effects of feeding fish oil on mesenteric lymph node cytokine responses in obese leptin receptor-deficient JCR:LA-cp rats.

    PubMed

    Ruth, M R; Proctor, S D; Field, C J

    2009-01-01

    berrant immune responses have been identified in obesity; however, immune cells of lymph nodes residing in the inflammatory environment of visceral adipose tissue have been largely overlooked. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) can reduce inflammation and modify T-cell function and therefore may improve immune function in obesity. Thus, we determined the effects of feeding fish oil (FO) containing EPA and DHA on mesenteric lymph node (MLN) immune cell function. In this study, 14-week-old obese, leptin receptor-deficient JCR:LA-cp rats (cp/cp) (n=10 per group) were randomized to one of three nutritionally adequate diets for 3 weeks: control (ctl, 0% EPA+DHA), low FO (LFO, 0.8% w/w EPA+DHA) or high FO (HFO, 1.4% w/w EPA+DHA). Lean JCR:LA-cp (Cp/cp or Cp/Cp) rats (n=5) were fed ctl diet. MLN cell phospholipid (PL) fatty acid composition, phenotypes and cytokine production were measured. Obese ctl rats produced more IL-1beta, IL-4 and IL-10, despite a higher proportion of (n-3) polyunsaturated fatty acids (PUFAs) and a lower (n-6):(n-3) PUFA ratio in MLN PL compared with lean ctl rats (P<0.05). Concanavalin A-stimulated IL-2 production did not differ from lean rats even though obese ctl rats had a lower proportion of CD4(+)CD25(+) cells (P<0.05). Feeding FO to obese rats increased the incorporation of (n-3) PUFA into MLN PL and normalized production of IL-1beta (HFO only), IL-4 and IL-10 to the levels similar to lean ctl rats (P<0.05). We demonstrate for the first time that obese JCR:LA-cp rats have impaired responses of MLN immune cells to mitogen stimulation and altered PL fatty acid composition. Feeding FO lowered the ex vivo inflammatory response (HFO only) and production of Th2 cytokines, without changing IL-2 production from ConA-stimulated splenocytes, which may occur independent of leptin signalling.

  9. An oil containing EPA and DHA from transgenic Camelina sativa to replace marine fish oil in feeds for Atlantic salmon (Salmo salar L.): Effects on intestinal transcriptome, histology, tissue fatty acid profiles and plasma biochemistry.

    PubMed

    Betancor, Mónica B; Li, Keshuai; Sprague, Matthew; Bardal, Tora; Sayanova, Olga; Usher, Sarah; Han, Lihua; Måsøval, Kjell; Torrissen, Ole; Napier, Johnathan A; Tocher, Douglas R; Olsen, Rolf Erik

    2017-01-01

    New de novo sources of omega 3 (n-3) long chain polyunsaturated fatty acids (LC-PUFA) are required as alternatives to fish oil in aquafeeds in order to maintain adequate levels of the beneficial fatty acids, eicosapentaenoic and docosahexaenoic (EPA and DHA, respectively). The present study investigated the use of an EPA+DHA oil derived from transgenic Camelina sativa in Atlantic salmon (Salmo salar) feeds containing low levels of fishmeal (35%) and fish oil (10%), reflecting current commercial formulations, to determine the impacts on tissue fatty acid profile, intestinal transcriptome, and health of farmed salmon. Post-smolt Atlantic salmon were fed for 12-weeks with one of three experimental diets containing either a blend of fish oil/rapeseed oil (FO), wild-type camelina oil (WCO) or transgenic camelina oil (DCO) as added lipid source. The DCO diet did not affect any of the fish performance or health parameters studied. Analyses of the mid and hindgut transcriptomes showed only mild effects on metabolism. Flesh of fish fed the DCO diet accumulated almost double the amount of n-3 LC-PUFA than fish fed the FO or WCO diets, indicating that these oils from transgenic oilseeds offer the opportunity to increase the n-3 LC-PUFA in farmed fish to levels comparable to those found a decade ago.

  10. An oil containing EPA and DHA from transgenic Camelina sativa to replace marine fish oil in feeds for Atlantic salmon (Salmo salar L.): Effects on intestinal transcriptome, histology, tissue fatty acid profiles and plasma biochemistry

    PubMed Central

    Betancor, Mónica B.; Li, Keshuai; Sprague, Matthew; Bardal, Tora; Sayanova, Olga; Usher, Sarah; Han, Lihua; Måsøval, Kjell; Torrissen, Ole; Napier, Johnathan A.; Tocher, Douglas R.; Olsen, Rolf Erik

    2017-01-01

    New de novo sources of omega 3 (n-3) long chain polyunsaturated fatty acids (LC-PUFA) are required as alternatives to fish oil in aquafeeds in order to maintain adequate levels of the beneficial fatty acids, eicosapentaenoic and docosahexaenoic (EPA and DHA, respectively). The present study investigated the use of an EPA+DHA oil derived from transgenic Camelina sativa in Atlantic salmon (Salmo salar) feeds containing low levels of fishmeal (35%) and fish oil (10%), reflecting current commercial formulations, to determine the impacts on tissue fatty acid profile, intestinal transcriptome, and health of farmed salmon. Post-smolt Atlantic salmon were fed for 12-weeks with one of three experimental diets containing either a blend of fish oil/rapeseed oil (FO), wild-type camelina oil (WCO) or transgenic camelina oil (DCO) as added lipid source. The DCO diet did not affect any of the fish performance or health parameters studied. Analyses of the mid and hindgut transcriptomes showed only mild effects on metabolism. Flesh of fish fed the DCO diet accumulated almost double the amount of n-3 LC-PUFA than fish fed the FO or WCO diets, indicating that these oils from transgenic oilseeds offer the opportunity to increase the n-3 LC-PUFA in farmed fish to levels comparable to those found a decade ago. PMID:28403232

  11. [Pressure-volume analysis of wound suction drainage containers and suction capacity of drainage tubes].

    PubMed

    Mohadjer, C; Siegert, R; Jäger, H; Weidauer, H

    1994-01-01

    Four low-vacuum systems and eight high-vacuum systems were examined with special reference to the pressure-volume relations. The maximum filling volume for adequate transport of wound secretion was determined for each type. The use of a synthetic wound fluid instead of water resulted in a smaller aspiration volume. Enlargement of the tube diameter resulted in a reduced initial vacuum for the low-vacuum systems, whereas the high-vacuum systems were not affected. Normal drain tubes were compared with "Ulm drains" and silicon tubes for suction capacity. The suction maximum of normal tubes and silicon tubes was located at the proximal holes of the perforated tubes. The "Ulm drain," with perforation diameter increasing continuously to the distal end of the tube, was found to exert suction even at the more distal part of the tube. It is estimated that this tube allows locally more balanced vacuum in the wound.

  12. 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.

  13. Screening of pesticides and polycyclic aromatic hydrocarbons in feeds and fish tissues by gas chromatography coupled to high-resolution mass spectrometry using atmospheric pressure chemical ionization.

    PubMed

    Nácher-Mestre, Jaime; Serrano, Roque; Portolés, Tania; Berntssen, Marc H G; Pérez-Sánchez, Jaume; Hernández, Félix

    2014-03-12

    This paper reports a wide-scope screening for detection and identification of pesticides and polycyclic aromatic hydrocarbons (PAHs) in feeds and fish tissues. QuEChERS sample treatment was applied, using freezing as an additional cleanup. Analysis was carried out by gas chromatography coupled to hybrid quadrupole time-of-flight mass spectrometry with atmospheric pressure chemical ionization (GC-(APCI) QTOF MS). The qualitative validation was performed for over 133 representative pesticides and 24 PAHs at 0.01 and 0.05 mg/kg. Subsequent application of the screening method to aquaculture samples made it possible to detect several compounds from the target list, such as chlorpyrifos-methyl, pirimiphos-methyl, and ethoxyquin, among others. Light PAHs (≤4 rings) were found in both animal and vegetable samples. The reliable identification of the compounds was supported by accurate mass measurements and the presence of at least two representative m/z ions in the spectrum together with the retention time of the peak, in agreement with the reference standard. Additionally, the search was widened to include other pesticides for which standards were not available, thanks to the expected presence of the protonated molecule and/or molecular ion in the APCI spectra. This could allow the detection and tentative identification of other pesticides different from those included in the validated target list.

  14. 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.

  15. 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.

  16. Determination of Minimum Suction Level Necessary for Field Dental Units

    DTIC Science & Technology

    2010-04-01

    MILITARY MEDICINE, 175, 4:285, 2010 Determination of Minimum Suction Level Necessary for Field Dental Units David G. Charlton, DDS ABSTRACT A...significant problem with most field dental units is that their suction is too weak to effectively remove debris from the mouth. The purpose of this study was...to determine the minimum clinically acceptable suction level for routine dentistry. A vacuum pump was connected to a high-volume dental evacuation

  17. Preliminary Analysis on Matric Suction for Barren Soil

    NASA Astrophysics Data System (ADS)

    Azhar, A. T. S.; Fazlina, M. I. S.; Aziman, M.; Fairus, Y. M.; Azman, K.; Hazreek, Z. A. M.

    2016-11-01

    Most research conducted on slope failures can broadly be attributed to the convergence of three factors, i.e. rainfall, steepness of slope, and soil geological profile. The mechanism of the failures is mainly due to the loss of matric suction of soils by rainwater. When rainwater infiltrates into the slopes, it will start to saturate the soil, i.e., reduce the matric suction. A good understanding of landslide mechanisms and the characteristics of unsaturated soil and rock in tropical areas is crucial in landslide hazard formulation. Most of the slope failures in unsaturated tropical residual soil in Malaysia are mainly due to infiltration, especially during intense and prolonged rainfall, which reduces the soil matric suction and hence decreases the stability of the slope. Therefore, the aim of this research is to determine the matric suction for barren soil and to model an unsaturated slope with natural rainfall to evaluate the effects of matric suction on rainfall intensity. A field test was carried out using the Watermark Soil Moisture Sensor to determine the matric suction. The sensor was connected to a program called SpecWare 9 Basic which also used Data Logging Rain gauge Watermark 1120 to measure the intensity and duration of rainfall. This study was conducted at the Research Centre for Soft Soil which is a new Research and Development (R & D) initiative by Universiti Tun Hussein Onn Malaysia, Parit Raja. Field observation showed that the highest daily suction was recorded during noon while the lowest suction was obtained at night and early morning. The highest matric suction for loose condition was 31.0 kPa while the highest matric suction for compacted condition was 32.4 kPa. The results implied that the field suction variation was not only governed by the rainfall, but also the cyclic evaporation process. The findings clearly indicated that the changes in soil suction distribution patterns occurred due to different weather conditions.

  18. Method of producing suction manifolds for automobile engines

    SciTech Connect

    Enomoto, M.; Shimizu, Y.

    1984-05-29

    A method of producing suction manifolds for automobile engines is disclosed. In forming an exhaust gas re-circulating pipe passage integrally with a suction manifold for re-circulating exhaust gases from the engine to the suction manifold, a curved pipe of aluminum having a high-temperature resistant film formed on its surface is molded into a manifold of aluminum alloy at a suitable place on the latter.

  19. 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

  20. Transition Flight Experiments on a Swept Wing with Suction

    NASA Technical Reports Server (NTRS)

    Maddalon, D. V.; Collier, F. S., Jr.; Montoya, L. C.; Putnam, R. J.

    1989-01-01

    Flight boundary-layer transition experiments were conducted on a 30 degree swept wing with a perforated leading-edge suction panel. The transition location on the panel was changed by systematically varying the location and amount of suction. 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 flight condition and suction variation. Amplification factor correlations with transition location were made for various suction configurations using a state-of-the-art linear stability theory which accounts for body and streamline curvature and compressibility.

  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.; Putnam, R. J.

    1989-01-01

    Flight boundary-layer transition experiments were conducted on a 30-degree swept wing with a perforated leading-edge suction panel. The transition location on the panel was changed by systematically varying the location and amount of suction. 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 flight condition and suction variation. Amplification factor correlations with transition location were made for various suction configurations using a state-of-the-art linear stability theory which accounts for body and streamline curvature and compressibility.

  2. Transition flight experiments on a swept wing with suction

    NASA Technical Reports Server (NTRS)

    Maddalon, D. V.; Collier, F. S., Jr.; Montoya, L. C.; Putnam, R. J.

    1989-01-01

    Flight boundary-layer transition experiments were conducted on a 30-degree swept wing with a perforated leading-edge suction panel. The transition location on the panel was changed by systematically varying the location and amount of suction. 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 flight condition and suction variation. Amplification factor correlations with transition location were made for various suction configurations using a state-of-the-art linear stability theory which accounts for body and streamline curvature and compressibility.

  3. Ridge suction drives plume-ridge interactions

    NASA Astrophysics Data System (ADS)

    Niu, Y.; Hékinian, R.

    2003-04-01

    Deep-sourced mantle plumes, if existing, are genetically independent of plate tectonics. When the ascending plumes approach lithospheric plates, interactions between the two occur. Such interactions are most prominent near ocean ridges where the lithosphere is thin and the effect of plumes is best revealed. While ocean ridges are mostly passive features in terms of plate tectonics, they play an active role in the context of plume-ridge interactions. This active role is a ridge suction force that drives asthenospheric mantle flow towards ridges because of material needs to form the ocean crust at ridges and lithospheric mantle in the vicinity of ridges. This ridge suction force increases with increasing plate separation rate because of increased material demand per unit time. As the seismic low-velocity zone atop the asthenosphere has the lowest viscosity that increases rapidly with depth, the ridge-ward asthenospheric flow is largely horizontal beneath the lithosphere. Recognizing that plume materials have two components with easily-melted dikes/veins enriched in volatiles and incompatible elements dispersed in the more refractory and depleted peridotitic matrix, geochemistry of some seafloor volcanics well illustrates that plume-ridge interactions are consequences of ridge-suction-driven flow of plume materials, which melt by decompression because of lithospheric thinning towards ridges. There are excellent examples: 1. The decreasing La/Sm and increasing MgO and CaO/Al_2O_3 in Easter Seamount lavas from Salas-y-Gomez Islands to the Easter Microplate East rift zone result from progressive decompression melting of ridge-ward flowing plume materials. 2. The similar geochemical observations in lavas along the Foundation hotline towards the Pacific-Antarctic Ridge result from the same process. 3. The increasing ridge suction force with increasing spreading rate explains why the Iceland plume has asymmetric effects on its neighboring ridges: both topographic and

  4. Transition control by periodic suction-blowing

    NASA Technical Reports Server (NTRS)

    Biringen, S.; Nutt, W. E.; Caruso, M. J.

    1985-01-01

    The applicability of active control of transition by period suction-blowing is investigated via direct numerical simulations of the Navier-Stokes equations. The time-evolution of finite-amplitude disturbances in plane channel flow is compared in detail with and without control. The analysis indicates that for relatively small three-dimensional amplitudes, a two-dimensional control effectively reduces disturbance growth rates even for linearly unstable Reynolds numbers. After the flow goes through secondary instability, three-dimensional control seems necessary to stabilize the flow. An investigation of the temperature field suggests that passive temperature contamination is operative to reflect the vorticity dynamics during transition.

  5. Influence of feeding a fish oil-containing diet to mature, overweight dogs: Effects on lipid metabolites, postprandial glycaemia and body weight.

    PubMed

    de Godoy, M R C; McLeod, K R; Harmon, D L

    2017-05-15

    The objective 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 (BW) of mature, overweight dogs. Seven female dogs were randomly assigned to one of two isonitrogenous and isocaloric diets, control (CO) or FO (FO), in a crossover design. Experimental periods were 69 day, separated by a washout period of 30 day. At the beginning of the experiment, and at 30 and 60 day of feeding the experimental diets, the dogs were infused with D-glucose (2 g/kg BW) through an intravenous catheter. Blood samples were collected for 3 hr to perform a glucose tolerance test. Nitrogen balance measurements began at 06:30 on d 63 of each experimental period and ended at 06:30 on d 69. On d 66 of each period, a single dose (7.5 mg/kg) of (15) N-glycine was administered orally for determination of protein turnover. Incremental area under the curve and glucose concentration at peak did not differ between treatments or among sampling days within treatment. Glucose half-life tended to decrease (p < .10) in the FO treatment on day 30 when compared to baseline (day 0). β-hydroxybutyrate, non-esterified fatty acid (NEFA) and triglycerides did not differ within or between treatments. Cholesterol decreased (p < .05) on the FO treatment on day 30, 60 and 69 when compared to day 0. High-density lipoprotein (HDL) decreased (p < .05) in the FO treatment on day 69 when compared to day 0. Body weight, food intake, faecal excretion, DM and N digestibilities, N balance and protein turnover were not different between diets. Overall, FO-containing diet decreases cholesterol in mature overweight dogs; however, further research is warranted to verify the effects of FO on glucose metabolism. © 2017 Blackwell Verlag GmbH.

  6. Suppression of oxidative stress in aging NZB/NZW mice: effect of fish oil feeding on hepatic antioxidant status and guanidino compounds.

    PubMed

    Kim, You Jung; Yokozawa, Takako; Chung, Hae Young

    2005-10-01

    Oxidative stress caused by excessive reactive species (RS) and lipid peroxidation is known to be casually linked to age-related inflammation. To test the hypothesis that fish oil (FO) intake has a beneficial effect on nephritis due to its suppressive action of oxidative stress and the enhancement of antioxidant defenses, we examined the effect of dietary FO on various oxidative stress-related parameters and guanidino compound (GC) levels using (NZB x NZW) F1 (B/W) mice. These mice were fed diets supplemented with either 5% corn oil (control) or 5% FO. At 4 and 9 months of age, the hepatic oxidative status was estimated by assessing RS generation produced from xanthine oxidase, the prostaglandin pathway and lipid peroxidation. To evaluate the effect of FO on redox status, including antioxidant defenses, GSH and GSSG levels and antioxidant enzyme activities were measured. To correlate the extent of oxidative status with the nephritic condition, creatinine, guanidino acetic acid and arginine levels were measured. Results indicated that increased levels of lipid peroxidation, RS generation and xanthine oxidase activity with age were all significantly suppressed by FO feeding. Furthermore, reduced GSH levels, GSH/GSSG ratio and antioxidant enzyme activities in the FO-fed mice were effectively enhanced compared to the corn oil-fed mice. Among several GCs, the age-related increase of creatinine level was blunted by FO. Based on these results, we propose that dietary FO exerts beneficial effects in aged, nephritic mice by suppressing RS, superoxide and lipid peroxidation, and by maintaining a higher GSH/GSSG ratio and antioxidant enzyme activities.

  7. 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.

  8. 21 CFR 878.5040 - Suction lipoplasty system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Suction lipoplasty system. 878.5040 Section 878.5040 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.5040 Suction lipoplasty...

  9. 21 CFR 878.5040 - Suction lipoplasty system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Suction lipoplasty system. 878.5040 Section 878.5040 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.5040 Suction lipoplasty...

  10. 21 CFR 878.5040 - Suction lipoplasty system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Suction lipoplasty system. 878.5040 Section 878.5040 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.5040 Suction lipoplasty...

  11. 21 CFR 878.5040 - Suction lipoplasty system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Suction lipoplasty system. 878.5040 Section 878.5040 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.5040 Suction lipoplasty...

  12. 21 CFR 870.4430 - Cardiopulmonary bypass intracardiac suction control.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Cardiopulmonary bypass intracardiac suction control. 870.4430 Section 870.4430 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND... intracardiac suction control is a device which provides the vacuum and control for a cardiotomy return...

  13. 21 CFR 870.4430 - Cardiopulmonary bypass intracardiac suction control.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Cardiopulmonary bypass intracardiac suction control. 870.4430 Section 870.4430 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND... intracardiac suction control is a device which provides the vacuum and control for a cardiotomy return...

  14. Effectiveness of closed suction drainage tip culture in hip arthroplasty.

    PubMed

    Park, Jai Hyung; Shon, Hyun Chul; Kim, Ji Wan; Park, Se Jin; Ko, Taeg Su; Park, Jong Hyon

    2016-01-01

    The aim of the present study was to investigate the correlation between bacterial growth in closed suction drainage tip culture and periprosthetic joint infection (PJI). Retrospective review included 256 patients who had undergone hip arthroplasty in which the closed suction drainage tip was cultured. Follow-up periods were longer than a year. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated in order to determine the significance of closed suction drainage tip culture in early diagnosis of infection. Patients with positive culture test were monitored to determine the effect of change in antibiotics on treatment of early infection. Eight of the 13 infections showed positive results from closed suction drainage tip culture. Eleven of the 243 non-infectious cases showed positive results after closed suction drainage tip culture (p<0.001). Sensitivity of closed suction drainage tip culture was 61.5%, with a specificity of 95.5%. Positive and negative predictive values were 42.1% and 97.9%, respectively. Systemic antibiotics were administered according to in vitro sensitivity of bacteria cultured from closed suction drainage tip in 13 of 19 positive culture cases. No statistically significant difference in infection risk was observed between the antibiotics group and the group to which antibiotics were not administered (p=0.51). Closed suction drainage tip culture can aid in the early detection of infection.

  15. 21 CFR 874.5350 - Suction antichoke device.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) Identification. A suction antichoke device is a device intended to be used in an emergency situation to remove, by the application of suction, foreign objects that obstruct a patient's airway to prevent asphyxiation to the patient. (b) Classification. Class III. (c) Date PMA or notice of completion of PDP...

  16. 21 CFR 878.5040 - Suction lipoplasty system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    .... (a) Identification. A suction lipoplasty system is a device intended for aesthetic body contouring... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Suction lipoplasty system. 878.5040 Section 878.5040 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES...

  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. Complete feeds-intensive systems

    USDA-ARS?s Scientific Manuscript database

    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. Measurement of suction and discharge pressure pulsations in waterflood facilities

    SciTech Connect

    Wurzbach, W.M. Jr.; Happel, P.E.

    1983-01-01

    Recent mechanical problems with reciprocating water injection pumps prompted a study of suction and discharge pressure conditions in the Red River Bull Bayou Unit, Red River Parish, La. Frequent failures in plunger pump components and discharge lines were occurring at several injection sites within the unit. Electronic surveillance equipment consisting of an oscilloscope and pressure transducers was utilized to locate and identify large suction and discharge pressure pulses. The severity of these pulses could not be identified with standard pressure gages. The data obtained with the electronic equipment indicated that cavitation was occurring on the suction side of the pumps due to insufficient net positive suction head. The large pressure pulsations caused by this cavitation problem were carried through the pump and amplified on the discharge side. Changes in the suction and discharge piping design eliminated cavitation and effectively reduced the peak pressure pulses.

  1. Transition flight experiments on a swept wing with suction

    NASA Technical Reports Server (NTRS)

    Maddalon, D. V.; Land, C. K.; Collier, F. S.; Montoya, L. C.

    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. 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.

  3. Transition flight experiments on a swept wing with suction

    NASA Technical Reports Server (NTRS)

    Maddalon, D. V.; Land, C. K.; Collier, F. S.; Montoya, L. C.

    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.

  4. Music therapy following suctioning: four case studies.

    PubMed

    Burke, M; Walsh, J; Oehler, J; Gingras, J

    1995-10-01

    This descriptive study evaluates and compares the effectiveness of music, presented both aurally and vibrotactilely, in reducing agitation and physiological instability following a stress-producing intervention (suctioning) in infants with bronchopulmonary dysplasia. Heart rate, oxygen saturation levels, level of arousal, stressful facial expressions, and autonomic indicators were recorded for each of four preterm infants. All infants experienced a reduction in the level of arousal during the taped music intervention when compared with the control condition. Three infants spent an increased amount of time in a quiet alert state and had improved oxygen saturation levels during the vibrotactile intervention. All infants spent more time sleeping during the taped music condition than without music or with the vibrotactile intervention. Results suggest that music is effective in reducing stress-related behaviors for some infants.

  5. The effect of suction during die fill on a rotary tablet press.

    PubMed

    Jackson, S; Sinka, I C; Cocks, A C F

    2007-02-01

    Die fill on a rotary tablet press involves complex powder flow phenomena. Conventional techniques for measuring flowability do not normally provide information that is directly relevant to the design of powder feed systems or to the selection of press parameters for the die filling process. Sinka et al. [I.C. Sinka, L.C.R. Schneider, A.C.F. Cocks, Measurement of the flow properties of powders with special reference to die fill, in: International Journal of Pharmaceutics 280 (1-2) (2004) 27-38] used an experimental shoe-die system to characterise the flow behaviour of pharmaceutical powders. A rigorous data analysis procedure was developed by Schneider et al. [L.C.R. Schneider, I.C. Sinka, A.C.F. Cocks, Characterisation of the flow behaviour of pharmaceutical powders using a model die-shoe filling system, in: Powder Technology (in press)] to evaluate the experimental results, however, when scaling the results to a rotary tablet press, the die fill efficiency was underpredicted by a factor of approximately 2, because the experimental system did not capture major features of the rotary press flow process. The suction effect, whereby the lower punch is moved downwards while the top of the die is exposed to powder in the feed system, is a key element of the process. In this note we describe the development of a model shoe-die system that allows the effect of suction to be investigated. The results demonstrate the improvement offered by suction and illustrate how a fundamental understanding of die fill phenomena could assist the selection of process parameters to maximise the operational speed of a rotary press.

  6. 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.

  7. 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 .

  8. A Usability Comparison of Laser Suction Handpieces for Percutaneous Nephrolithotomy.

    PubMed

    Dauw, Casey A; Borofsky, Michael S; York, Nadya; Lingeman, James E

    2016-11-01

    The holmium laser has revolutionized the practice of minimally invasive endoscopy for kidney stones. Recently, a novel, rigid handpiece for use in percutaneous nephrolithotomy (PCNL) that couples the holmium laser with suction has been developed. To date, limited data exist regarding the usability and ergonomics of such treatment systems. We thus sought to compare surgeon-rated usability with three different suction laser handpieces in a porcine model. We performed bilateral reverse PCNL on four female domestic farm pigs. After induction of general anesthesia, percutaneous access was obtained into each kidney by using biplanar fluoroscopy and 8 mm stones (plaster of Paris) were inserted into the calix or renal pelvis for treatment. Four surgeons tested the LASER Suction Tube (Karl Storz(®), Germany), LithAssist™ (Cook(®) Medical), and Suction Handpiece (HP) (Lumenis(®), Israel) by using a combination of fragmentation (5 Joules/20 Hertz) and dusting (0.8 Joules/80 Hertz) settings on the Lumenis pulse 120 H laser. The primary outcome assessed was the ease of use of the three devices as measured by a surgeon questionnaire. A total of 15 stones were treated in 8 renal units. The mean time required for stone fragmentation was 8 min. The mean handling and suction efficiency scores were similar between devices. The Suction HP offered the best laser fiber visibility during lithotripsy. Suction laser handpieces offer an option to treat renal stones via PCNL, with limited differences noted in most surgeon ratings between devices.

  9. 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.

  10. 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

    USDA-ARS?s Scientific Manuscript database

    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...

  11. Cellular aggregation and trauma in cardiotomy suction systems.

    PubMed Central

    Wright, G; Sanderson, J M

    1979-01-01

    Experiments in dogs showed that the high levels of cellular aggregation and trauma caused by cariodtomy suction can be considerably reduced by the avoidance of air aspiration. A hypothesis is proposed to explain this on the basis of shear stresses in the inlet cannula. Roller pump suction was also found to be slightly more traumatic than vaccum suction, but contact of the blood with the pericardium had no effect so long as the pericardium and epicardium had been previously washed with saline. PMID:515984

  12. Portable suction unit failure in a rural EMS system.

    PubMed

    Risavi, Brian L; Sabotchick, K J; Heile, Christopher J

    2013-08-01

    Portable suction units used by EMS personnel are utilized infrequently and often are powered by batteries. Lack of use and inspection often results in failure of the device when it is needed. The purpose of this study was to examine the incidence of portable suction unit failure in a rural EMS system and to identify the reasons for failures. A convenience sample was obtained through both random inspections by the staff of a regional EMS council and data from twice monthly checks reported by respective EMS agencies following a standard protocol for each unit. A standard protocol was used, including checking the vacuum level on each suction unit and inspecting the tubing, canister, and battery. Each inspector assessed whether the unit was capable of achieving 300 mmHg of suction within four seconds. Also, the unit was inspected for any signs of misalignment or dry rot of the gasket, kinking of suction hose, damage to the suction canister, weak/dead battery, or defective pump. Findings were recorded. Over a two-year period, 9,631 suction unit inspections were completed. There were 233 failures (2.4%) noted. The majority (126, 54.1%) were due to battery failure. Seventy-three units failed due to other reasons (not recorded, switch failure, battery not seated). Ten inspections failed due to incorrect assembly. Nineteen inspections failed due to defects with the suction canister. Five inspections failed due to kinked/disconnected suction tubing. Only a relatively small percentage of inspections of suction units revealed failures (4.6% Advanced Life Support, 8.6% Basic Life Support) using the above-stated criteria. However, given the importance of airway management and potential complications associated with airway compromise, including aspiration pneumonia, hypoxia, and hemodynamic instability, this is of concern relative to the morbidity and mortality that could be related to airway failure. Due to the relative infrequency of use and the nature of portable suction units

  13. [The value of wound drainage with or without suction].

    PubMed

    Schmidt, J; Hasselbach, A; Schnorr, W; Baranek, T; Letsch, R

    2005-11-01

    Even though the discussion for desisting from wound drainage has arisen, this is not reflected in the reality of surgical treatment. In more than 90% of all procedures wound drainage is used. It remains to be proven whether suction drainage actually is superior to gravity drainage in everyday use. In a random study with 200 patients it was proven that suction drainage shows no significant advantage in liquid quantum, haematoma and the frequency of complications. We conclude that the economically favourable gravity drainage can replace the more expensive suction drainage in most cases.

  14. Centrifugal pumps: which suction specific speeds are acceptable

    SciTech Connect

    Hallam, J.L.

    1982-04-01

    Suction specific speed is an important consideration when purchasing or analyzing centrifugal pumps. There is a direct correlation between this parameter, pump reliability and maintenance expenses. This article demonstrates that in a large Gulf Coast oil refinery, centrifugal pumps with a suction specific speed greater than 11,000 failed at a frequency nearly twice that of centrifugal pumps with suction specific speed less than 11,000. This study consisted primarily of hydrocarbon pumps with an average horsepower of 150 hp. Results may vary some from those found if high energy water pumps are studied. 5 refs.

  15. [Feeding habits and trophic ecology of the fish Lutjanus griseus (Pisces: Lutjanidae) associated with submerged vegetation in Laguna de Términos, Campeche, Mexico].

    PubMed

    Guevara, Emma; Alvarez, Hernán; Mascaró, Maite; Rosas, Carlos; Sánchez, Alberto

    2007-01-01

    In Campeche, Mexico, the Laguna de Términos has Thalassia testudinum beds inhabited by the grey snapper, Lutjanus griseus (Linnaeus 1758). Along one year, we collected 994 individuals and 672 had food in their stomachs; we recorded number, weight, and frequency oftrophic groups, and the index of relative importance. Dominant food components were Farfantepenaeus duorarum and Palemonetes octaviae, Eucinostomus gula (Cuvier 1830) and Libinia dubia. Salinity and temperature were related to the number of individuals collected and with greater fish consumption by large L. griseus. The trophic niche breadth index was calculated for six size-classes of fish. The smallest and the largest fish had the lowest index values, whereas medium-size snappers had higher values. This snapper has a preference for habitats with submerged vegetation. The percentage of fish with food in their stomachs was higher during dark hours, providing evidence of the nocturnal habits of this fish.

  16. 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

  17. 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.

  18. Growth and Feed Efficiency of Juvenile Channel Catfish Ictalurus punctatus Fed Diets Containing Various Levels of Fish Meal at Different Water Temperatures

    USDA-ARS?s Scientific Manuscript database

    Unlike warm-blooded animals, channel catfish do not feed consistently when water temperatures are below 20°C and generally stop eating at temperatures of 10°C and below. Many catfish producers choose not to feed during winter months for various reasons, one of which is that it is difficult to see a...

  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. Differential effects of safflower oil versus fish oil feeding on insulin-stimulated glycogen synthesis, glycolysis, and pyruvate dehydrogenase flux in skeletal muscle: a 13C nuclear magnetic resonance study.

    PubMed

    Jucker, B M; Cline, G W; Barucci, N; Shulman, G I

    1999-01-01

    To examine the effects of safflower oil versus fish oil feeding on in vivo intramuscular glucose metabolism and relative pyruvate dehydrogenase (PDH) versus tricarboxylic acid (TCA) cycle flux, rats were pair-fed on diets consisting of 1) 59% safflower oil, 2) 59% menhaden fish oil, or 3) 59% carbohydrate (control) in calories. Rates of glycolysis and glycogen synthesis were assessed by monitoring [1-(13)C]glucose label incorporation into [1-(13)C]glycogen, [3-(13)C]lactate, and [3-(13)C]alanine in the hindlimb of awake rats via 13C nuclear magnetic resonance (NMR) spectroscopy during a euglycemic (approximately 6 mmol/l) hyperinsulinemic (approximately 180 microU/ml) clamp. A steady-state isotopic analysis of lactate, alanine, and glutamate was used to determine the relative PDH versus TCA cycle flux present in muscle under these conditions. The safflower oil-fed rats were insulin resistant compared with control and fish oil-fed rats, as reflected by a markedly reduced glucose infusion rate (Ginf) during the clamp (21.4 +/- 2.3 vs. 31.6 +/- 2.8 and 31.7 +/- 1.9 mg x kg(-1) x min(-1) in safflower oil versus control and fish oil groups, respectively, P < 0.006). This decrease in insulin-stimulated glucose disposal in the safflower oil group was associated with a lower rate of glycolysis (21.7 +/- 2.2 nmol x g(-1) x min(-1)) versus control (62.1 +/- 10.3 nmol x g(-1) x min(-1), P < 0.001) and versus fish oil (45.7 +/- 6.7 nmol x g(-1) x min(-1), P < 0.04), as no change in glycogen synthesis (103 +/- 15, 133 +/- 19, and 125 +/- 14 nmol x g(-1) x min(-1) in safflower oil, fish oil, and control, respectively) was detected. The intramuscular triglyceride (TG) content was increased in the safflower oil group (7.3 +/- 0.8 micromol/g) compared with the control group (5.2 +/- 0.8 micromol/g, P < 0.05) and the fish oil group (3.6 +/- 1.1 micromol/g, P < 0.01). Conversely, the percent PDH versus TCA cycle flux was decreased in the safflower oil (43 +/- 8%) versus the control

  1. 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...

  2. 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...

  3. 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...

  4. 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...

  5. 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...

  6. Influence of localised double suction on a turbulent boundary layer

    NASA Astrophysics Data System (ADS)

    Oyewola, O.; Djenidi, L.; Antonia, R. A.

    2007-07-01

    The effects of localised suction applied through a pair of porous wall strips on a turbulent boundary layer have been quantified through the measurements of mean velocity and Reynolds stresses. The results indicate that the use of second strip extends the pseudo-relaminarisation zone but also reduces the overshoot in the longitudinal and normal r.m.s. velocities. While the minimum r.m.s. occurs at x/δo=3.0 (one strip) and x/δo=12 (two strips), the reduction observed for the latter case is larger. Relative to no suction, the turbulence level is modified by suction and the effect is enhanced with double suction. This increased effectiveness reflects the fact that the second strip acts on a boundary layer whose near-wall active motion has been seriously weakened by the first strip.

  7. Coronary artery surgery: cardiotomy suction or cell salvage?

    PubMed Central

    Lau, Kelvin; Shah, Hetul; Kelleher, Andrea; Moat, Neil

    2007-01-01

    Coronary artery bypass grafting (CABG) today results in what may be regarded as acceptable levels of blood loss with many institutions avoiding allogeneic red cell transfusion in over 60% of their patients. The majority of cardiac surgeons employ cardiotomy suction to preserve autologous blood during on-pump coronary artery bypass surgery; however the use of cardiotomy suction is associated with a more pronounced systemic inflammatory response and a resulting coagulopathy as well as exacerbating the microembolic load. This leads to a tendency to increased blood loss, transfusion requirement and organ dysfunction. Conversely, the avoidance of cardiotomy suction in coronary artery bypass surgery is not associated with an increased transfusion requirement. There is therefore no indication for the routine use of cardiotomy suction in on-pump coronary artery surgery. PMID:17961227

  8. Flow Measurements in a Suction Sump by UVP

    NASA Astrophysics Data System (ADS)

    Funaki, Jiro; Neya, Masashi; Hattori, Masakatsu; Tanigawa, Hirochika; Hirata, Katsuya

    In the present study, to reveal the air entrainment mechanism into a suction pipe in a suction sump, the authors conduct flow-velocity measurements by UDM (Ultrasonic Doppler Method). Here, we consider the simplest geometry as a suction sump, that is, a straight channel with rectangle-cross section and a simple suction pipe near the end of the channel. Ultrasonic transducers are fixed outside the side, bottom and back walls with right/near-right angles and, we get three-dimensional time-mean velocity distributions and equi-vorticity contours. At first, measurement accuracy is checked by comparing velocity profiles by UDM with hydrogen bubble method. As a result, the authors show typical flow fields in the sump, and show the relation between flow pattern and air entrainment. Especially, we compare two cases where the air entrainment is often observed.

  9. Cost-effectiveness and safety of reusable tracheal suction tubes.

    PubMed

    Nanta, Penjan; Senarat, Wilawan; Tribuddharat, Chanwit; Danchaivijitr, Somwang

    2005-12-01

    To evaluate whether the repetitive use of disposable tracheal suction tubes is cost-effective and safe over the single use. The cost intrinsic to the washing, cleaning, re-sterilization by ethylene oxide gas, and processing was determined and compared to the cost generated by disposable tubes. The reused disposable suction tubes were also determined for their properties in physical characters and probable contamination and damages. The evaluation showed that cost from single-use disposable suction tubes (8.66 baht) was cheaper than expenses generated from processing steps for recycling of disposable tubes (9.92 baht). The use of a disposable tube only once should minimize the risks posed by the use of the potentially unsafe reused disposable tubes both to the patients and health care workers. Recycling of tracheal suction tubes was neither cost-effective nor safe.

  10. Efficacy of new filter suction to decrease the rate of occlusion and total suction time in a simulated total hip replacement operation.

    PubMed

    Yuenyongviwat, Varah; Iamthanaporn, Khanin; Hongnaparak, Theerawit; Tangtrakulwanich, Boonsin

    2014-01-01

    During orthopedic operations, such as total hip replacement or total knee replacement, there is a lot of bone debris from bone cutting and reaming that commonly causes surgical suction devices to occlude many times, which can prolong the operative time and increase the amount of bleeding for the patient. We developed a surgical filter suction system that we call the VY suction tube. The suction tube assembly consists of a tube filter within a housing assembly. The filter pore size was designed to prevent tissue or bone debris from passing through the filter, though it allows fluid to pass through. A simulated total hip replacement operation was performed to test the efficacy of this new suction device when compared with two other types of tube suction devices. The VY suction tube showed that the mean duration to remove all fluid from a simulated field was significantly shorter than the Pool suction tube (P=0.0009) and Frazier suction tube (P=0.0012). The study also showed that the VY suction tube has a lower rate of occlusion when compared with the Pool suction tube (P≤0.0001) and Frazier suction tube (P≤0.0001). Our new suction tube design shows good efficacy when removing fluid and debris from a simulated operative field. However, further studies in real clinical settings are needed.

  11. 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.

  12. Incidence and management of suction loss in refractive lenticule extraction.

    PubMed

    Wong, Chee Wai; Chan, Cordelia; Tan, Donald; Mehta, Jodhbir S

    2014-12-01

    To describe the incidence, management, and outcomes of suction loss in refractive lenticule extraction (ReLEx). Tertiary eye hospital. Retrospective case series. All patients who experienced suction loss during refractive lenticule extraction from March 9, 2010, to August 5, 2013, were evaluated preoperatively, including slitlamp biomicroscopy, fundoscopy, corneal topography, ultrasound pachymetry, manifest and cycloplegic refractions, and measurement of uncorrected (UDVA) and corrected (CDVA) distance visual acuities. Patients were followed at predetermined timepoints. At each follow-up visit, the UDVA and CDVA were measured and slitlamp biomicroscopy was performed. Manifest refraction was measured 1 and 3 months postoperatively. During the study period, 340 refractive lenticule extractions were performed. The overall cumulative incidence of suction loss was 3.2%. The incidence of suction loss was 4.3% (2/46) for femtosecond lenticule extraction, 4.4% (8/183) for small-incision lenticule extraction, and 0.9% (1/109) for pseudo small-incision lenticule extraction. Of the 11 eyes in which suction loss occurred, 8 (72.7%) had a UDVA of 20/30 or better and 9 (81.8%) had a spherical equivalent within ± 0.5 diopter of emmetropia at 3 months. Suction loss occurred in 4 eyes during the posterior lenticule cut, in 5 eyes during the anterior lenticule cut, and in 2 eyes during the lamellar flap cut. In 9 of these (81.8%), suction was reapplied and the procedure was completed without further complications. The incidence of suction loss during refractive lenticule extraction was relatively low. Good visual outcomes were achieved with appropriate management. Copyright © 2014 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  13. 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.

  14. 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

  15. 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...

  16. 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...

  17. 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.

  18. Control of Supersonic Boundary Layers Using Steady Suction

    NASA Technical Reports Server (NTRS)

    Balakumar, P.

    2006-01-01

    Control of supersonic boundary layers using steady suction through a series of very small two-dimensional strips is numerically investigated at a free stream Mach number of 1.8. The mean flow induced by rows of suction holes is also computed. Both the steady and unsteady solutions are obtained by solving the full Navier-Stokes equations using the 5th-order accurate weighted essentially non-oscillatory (WENO) scheme for space discretization and using third-order total-variationdiminishing (TVD) Runge-Kutta scheme for time integration. Computations for the two-dimensional cases are performed at suction coefficients 0.001 and 0.002 to investigate the stabilizing effects of suction. The simulation showed that a series of shock waves are generated at the slots. The stability results showed that the total amplification is reduced up to the end of the computational domain. However, the growth rates become larger at downstream distances away from the suction region. The computations for the suction holes showed the generation of Mach waves from each hole and the formation of longitudinal vortices.

  19. Measurement of suction and discharge pressure pulsations in waterflood facilities

    SciTech Connect

    Wurzbach, W.M.; Happel, P.E.

    1983-10-01

    Recent mechanical problems with reciprocating water injection pumps prompted a study of suction and discharge pressure conditions in the Red River Bull Bayou Unit, Red River Parish, Louisiana. Frequent failures in plunger pump components and discharge lines were occurring at several injection sites within the unit. Electronic surveillance equipment consisting of an oscilloscope and pressure transducers was utilized to locate and identify large suction and discharge pressure pulses. The severity of these pulses could not be identified with standard pressure gauges. The data obtained with the electronic equipment indicated that cavitation was occurring on the suction side of the pumps due to insufficient net positive suction head. The large pressure pulsations caused by this cavitation problem were carried through the pump and amplified on the discharge side. This resulted in excessive vibration and equipment overload. Subsequent changes in the suction and discharge piping design eliminated cavitation and effectively reduced the peak pressure pulses. These piping changes were done systematically to measure the effect of each change individually. The resulting measurements gave better insight to future piping design for both suction and discharge installations.

  20. 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

  1. Improvement in the high-fat diet-induced dyslipidemia and adiponectin levels by fish oil feeding combined with food restriction in obese KKAy mice.

    PubMed

    Wakutsu, Masaki; Tsunoda, Nobuyo; Mochi, Yasuki; Numajiri, Mitsuki; Shiba, Sachiko; Muraki, Etsuko; Kasono, Keizo

    2012-01-01

    The effect on weight reduction of fish oil combined with food restriction in comparison with that of beef tallow was investigated in high-fat diet-induced obese KKAy mice. Although the reduction of body and white adipose tissue weight was similar in the two groups, fish oil increased adiponectin levels in the plasma, improved dyslipidemia accompanied by suppression of lipid synthesis in the liver when compared with beef tallow.

  2. Fish Oil Feeding Modulates the Expression of Hepatic MicroRNAs in a Western-Style Diet-Induced Nonalcoholic Fatty Liver Disease Rat Model

    PubMed Central

    Shao, Yang; Feng, Han; Li, Na; Zhang, Hongyu

    2017-01-01

    Nonalcoholic fatty liver disease (NAFLD) is one of the most prevalent chronic liver diseases worldwide. Recent studies have indicated that fish oil supplementation has benefits against NAFLD. Our previous transcriptomic study has validated the effect of fish oil supplementation on altering hepatic gene expression in a NAFLD rat model. In the current study, we examined the effects of fish oil on the expression of hepatic microRNAs. Male Sprague–Dawley rats were fed with a lab chow (CON), high-fat high-cholesterol diet (WD), or WD supplemented with fish oil (FOH), respectively. Small RNAs were extracted from livers for RNA-sequencing. A total of 79 miRNAs were identified as differentially expressed miRNAs (DEMs) between FOH and WD groups, exemplified by rno-miR-29c-3p, rno-miR-30d-5p, rno-miR-33-5p, rno-miR-34a, and rno-miR-328a-3p. Functional annotation of DEMs predicted target genes suggested that the altered hepatic miRNAs contributed to fish oil modification of hepatic lipid metabolism and signaling transduction. Integrative analysis of DEMs and differentially expressed genes suggested that the expression difference of Pcsk9, Insig2, Per3, and Socs1/3 between FOH and WD groups may be due to miRNA modification. Our study reveals that fish oil supplementation alters hepatic expression of miRNAs, which may contribute to fish oil amelioration of NAFLD in rats. PMID:28691019

  3. Fish Oil Feeding Modulates the Expression of Hepatic MicroRNAs in a Western-Style Diet-Induced Nonalcoholic Fatty Liver Disease Rat Model.

    PubMed

    Wang, Hualin; Shao, Yang; Yuan, Fahu; Feng, Han; Li, Na; Zhang, Hongyu; Wu, Chaodong; Liu, Zhiguo

    2017-01-01

    Nonalcoholic fatty liver disease (NAFLD) is one of the most prevalent chronic liver diseases worldwide. Recent studies have indicated that fish oil supplementation has benefits against NAFLD. Our previous transcriptomic study has validated the effect of fish oil supplementation on altering hepatic gene expression in a NAFLD rat model. In the current study, we examined the effects of fish oil on the expression of hepatic microRNAs. Male Sprague-Dawley rats were fed with a lab chow (CON), high-fat high-cholesterol diet (WD), or WD supplemented with fish oil (FOH), respectively. Small RNAs were extracted from livers for RNA-sequencing. A total of 79 miRNAs were identified as differentially expressed miRNAs (DEMs) between FOH and WD groups, exemplified by rno-miR-29c-3p, rno-miR-30d-5p, rno-miR-33-5p, rno-miR-34a, and rno-miR-328a-3p. Functional annotation of DEMs predicted target genes suggested that the altered hepatic miRNAs contributed to fish oil modification of hepatic lipid metabolism and signaling transduction. Integrative analysis of DEMs and differentially expressed genes suggested that the expression difference of Pcsk9, Insig2, Per3, and Socs1/3 between FOH and WD groups may be due to miRNA modification. Our study reveals that fish oil supplementation alters hepatic expression of miRNAs, which may contribute to fish oil amelioration of NAFLD in rats.

  4. Fish oil feeding delays influenza virus clearance and impairs production of interferon-gamma and virus-specific immunoglobulin A in the lungs of mice.

    PubMed

    Byleveld, P M; Pang, G T; Clancy, R L; Roberts, D C

    1999-02-01

    Ingestion of fish oil can suppress the inflammatory response to injury and may impair host resistance to infection. To investigate the effect of a diet containing fish oil on immunity to viral infection, 148 BALB/c mice were fed diets containing 3 g/100 g of sunflower oil with either 17 g/100 g of fish oil or beef tallow for 14 d before intranasal challenge with live influenza virus. At d 1 and d 5 after infection, the mice fed fish oil had higher lung viral load and lower body weight (P < 0.05). In addition to the greater viral load and weight loss at d 5 after infection, the fish oil group consumed less food (P < 0.05) while the beef tallow group was clearing the virus, had regained their preinfection weights and was returning to their preinfection food consumption. The fish oil group had impaired production of lung interferon-gamma (IFN-gamma), serum immunoglobulin (Ig) G and lung IgA-specific antibodies (all P < 0. 05) although lung IFN-alpha/beta and the relative proportions of bronchial lymph node CD4+ and CD8+ T lymphocytes did not differ between groups after infection. The present study demonstrates a delay in virus clearance in mice fed fish oil associated with reduced IFN-gamma and antibody production and a greater weight loss and suppression of appetite following influenza virus infection. However, differences observed during the course of infection did not affect the ultimate outcome as both groups cleared the virus and returned to preinfection food consumption and body weight by d 7.

  5. 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.

  6. Determination of heavy metals in muscle tissue of six fish species with different feeding habits from the Danube River, Belgrade-public health and environmental risk assessment.

    PubMed

    Jovanović, Dragoljub A; Marković, Radmila V; Teodorović, Vlado B; Šefer, Dragan S; Krstić, Milena P; Radulović, Stamen B; Ivanović Ćirić, Jelena S; Janjić, Jelena M; Baltić, Milan Ž

    2017-04-01

    The aim of this study was to investigate the presence of heavy metals/metalloids (Pb, Cd, Hg, Cu, Fe, Zn, As) in the muscle tissue of fish from the Danube River (two locations: Zemun and Grocka). For the purpose of heavy metal determination in fish muscle, 120 samples of six different fish species, Prussian carp, barbel, bream, carp, pike perch, and catfish were collected. For determining heavy metals, we used microwave oven digestion and atomic absorption spectrometer methods. The highest average content of Pb (0.084 ± 0.004 mg kg(-1)), Cd (0.082 ± 0.003 mg kg(-1)), Hg (0.466 ± 0.006 mg kg(-1)), and As (0.333 ± 0.007 mg kg(-1)) was found in the muscle of carp (an omnivorous fish) from Grocka, while the highest average level of Fe (13.60 ± 0.03 mg kg(-1)) was deposited in bream (also omnivorous) from Zemun. Also, the average Cu level (1.62 ± 0.13 mg kg(-1)) was the highest in catfish muscle (a carnivorous fish) from Grocka, while the highest Zn content (11.16 ± 0.17 mg kg(-1)) was determined in muscle of Prussian carp (an omnivorous fish) from Zemun. The highest content of heavy metals (Cu, Fe, and Zn, respectively) in muscle of the six different types of fish from both locations was symmetrically arranged by species (catfish, barbel, and Prussian carp, respectively). Concentrations of Pb, Hg, and As in the Danube River fish muscle were under the maximum residual levels prescribed by the European Union (EU) and the maximum allowed concentrations (MAC) for Serbia. On the other hand, in all fish muscle from both locations (Zemun and Grocka), higher concentrations of Cd than prescribed (MAC) were found, with the exception of bream and pike perch.

  7. Single-run determination of polybrominated diphenyl ethers (PBDEs) di- to deca-brominated in fish meal, fish oil and fish feed by isotope dilution: application of automated sample purification and gas chromatography/ion trap tandem mass spectrometry (GC/ITMS).

    PubMed

    Blanco, Sonia Lucía; Vieites, Juan M

    2010-07-05

    The present paper describes the application of automated cleanup and fractionation procedures of the Power Prep system (Fluid Management Systems) for the determination of polybrominated diphenyl ethers (PBDEs) in feeding stuffs and fish meal and oil. Gas chromatography (GC) separation followed by ion trap tandem mass spectrometry detection in EI mode (ITMS) allowed the analysis of di- to deca-BDEs in the samples matrices used in fish aquaculture. The method developed enabled the determination of 26 native PBDE congeners and 11 (13)C(12)-labelled congeners, including deca-BDE 209, in a single-run analysis, using isotope dilution. The automated cleanup, consisting of a succession of multilayer silica and basic alumina columns previously applied by Wyrzykowska et al. (2009) [28] in combustion flue gas, was successfully applied in our complex matrices. The method allowed an increase in productivity, i.e. lower time was required to process samples, and simultaneous purification of several samples was achieved at a time, reducing analyst dedication and human error input. Average recoveries of 43-96% were obtained. GC/ITMS can overcome the complexity originating from the sample matrix, eliminating matrix effects by tandem MS, to enable the detection of congeners penta- to nona-BDEs where interferent masses were present. The provisional detection limits, estimated in the samples, were 5-30 pg for di-, tri-, tetra-, and penta-BDEs, 20-65 pg for hexa-, hepta-, octa- and nona-BDEs, and 105 pg for deca-BDE. Reduction of deca-BDE 209 blank values is of concern to ongoing research. Good accuracy was obtained by application of the whole procedure, representing an efficient, low-cost and fast alternative for routine analyses.

  8. 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. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. 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.

  10. Selective extraction of trace levels of polychlorinated and polybrominated contaminants by supercritical fluid-solid-phase microextraction and determination by gas chromatography/mass spectrometry. Application to aquaculture fish feed and cultured marine species.

    PubMed

    Rodil, R; Carro, A M; Lorenzo, R A; Cela Torrijos, R

    2005-04-01

    The persistence, ubiquity, and toxicity of polyhalogenated compounds, together with their presence in fish feed, make it necessary to monitor these organic pollutants in the routine quality assurance programs of aquaculture activities, as this food chain is a source of these toxic compounds for human consumers. A new approach based on simultaneous supercritical fluid extraction-sample cleanup, followed by solid-phase microextraction-gas chromatography/mass spectrometry (SFE-SPME-GC/MS/MS) has been developed as an advantageous analytical tool for the determination of 15 organohalogenated compounds (including pesticides, polychlorinated and polybrominated biphenyls, and polybrominated diphenyl ethers) in aquaculture feed at very low levels. The influence of several parameters in the efficiency of the SPE/SPME combination was systematically investigated by chemometric approaches. In the optimal conditions, the developed procedure provides an excellent linearity, detection, and quantification limits (below 10 pg/g) for most of the analytes investigated, being at the same time advantageous in terms of rapidity, convenience, and avoiding the need of toxic organic solvents. The procedure was applied to the analysis of aquaculture feed and cultured marine species and tested for accuracy against IAEA 406 reference material.

  11. 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

  12. Overcoming the problem of residual microbial contamination in dental suction units left by conventional disinfection using novel single component suction handpieces in combination with automated flood disinfection.

    PubMed

    Boyle, M A; O'Donnell, M J; Russell, R J; Galvin, N; Swan, J; Coleman, D C

    2015-10-01

    Decontaminating dental chair unit (DCU) suction systems in a convenient, safe and effective manner is problematic. This study aimed to identify and quantify the extent of the problems using 25 DCUs, methodically eliminate these problems and develop an efficient approach for reliable, effective, automated disinfection. DCU suction system residual contamination by environmental and human-derived bacteria was evaluated by microbiological culture following standard aspiration disinfection with a quaternary ammonium disinfectant or alternatively, a novel flooding approach to disinfection. Disinfection of multicomponent suction handpieces, assembled and disassembled, was also studied. A prototype manual and a novel automated Suction Tube Cleaning System (STCS) were developed and tested, as were novel single component suction handpieces. Standard aspiration disinfection consistently failed to decontaminate DCU suction systems effectively. Semi-confluent bacterial growth (101-500 colony forming units (CFU) per culture plate) was recovered from up to 60% of suction filter housings and from up to 19% of high and 37% of low volume suction hoses. Manual and automated flood disinfection of DCU suction systems reduced this dramatically (ranges for filter cage and high and low volume hoses of 0-22, 0-16 and 0-14CFU/plate, respectively) (P<0.0001). Multicomponent suction handpieces could not be adequately disinfected without prior removal and disassembly. Novel single component handpieces, allowed their effective disinfection in situ using the STCS, which virtually eliminated contamination from the entire suction system. Flood disinfection of DCU suction systems and single component handpieces radically improves disinfection efficacy and considerably reduces potential cross-infection and cross-contamination risks. DCU suction systems become heavily contaminated during use. Conventional disinfection does not adequately control this. Furthermore, multicomponent suction handpieces

  13. Feeding ecology and food composition of the black carp Mylopharyngodon piceus and the grass carp Ctenopharyngodon idella inhabiting the fish pond of Al-Abbassa fish hatchery with emphasis given to vector snails.

    PubMed

    el-Deeb, Fatma A; Ismail, Nahed M

    2004-08-01

    Stomach contents of M. piceus and C. idella collected from earthen fish ponds at Al-Abbassa fish hatchery during different seasons were examined. Food items were analyzed by three methods; the numerical (N%) percentage of point assessment (P%) and frequency of occurrence (F%). A comparison of the different methods emphasized the importance of snails as the major food resources in the diet of M. piceus during all seasons. During winter, stomachs of the most fish samples collected from fish ponds were empty or had traces of food. The index of relative importance (I.R.I) indicated that snails were the major food category in the diet of M. piceus during summer, autumn and spring represented by 7331, 9696 and 11670 respectively. Plants were the main food item in the diet of C. idella during summer (4604), meanwhile they came 3rd in relative importance in the diet during autumn and spring. Artificial fish food came as the 2nd food item in the diet of M. piceus during summer (1398.9) and autumn (5896.3) but it completely absent in spring. It is considered the main food item in diet of C. idella during autumn (10384.3) and spring (6293.5) and being 3rd in summer (1395.5). The results showed that snails reached highest level in the diet of M. piceus during spring (about 80% of all diet, decreased during summer (about 70%) and reached lowest proportion in autumn (50%). Plants exhibited marked seasonal variation in abundance with maximum level during summer (about 41% of all diet decreased during spring (27%) and autumn (22%). Artificial fish food was the highest in the diet of M. piceus during autumn (39%), decreased in summer (22%) until disappeared during spring. It reached highest level in diet of C. idella during autumn (49%), decreased in spring (38%) and reached lowest proportion during summer (21 %).

  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. [Is suction drainage necessary in elective total hip arthroplasty?].

    PubMed

    Major, Tibor; Bikov, András; Holnapy, Gergely; Bejek, Zoltán; Bakos, Bernadett; Szendrői, Miklós; Skaliczki, Gábor

    2016-07-01

    Several studies have been published which questioned the use of suction drain during elective hip arthroplasty. In this prospective study the authors examined how the use of suction drainage affected complications related to perioperative blood loss and hemorrhage in patients undergoing elective hip arthroplasty. Eighty-six patients undergoing elective hip arthroplasty were divided into two groups. In 54 patients ("drain" group) suction drains were used during operation, whereas in 32 patients no suction drain was applied. Perioperative blood loss, use of tranexamic acid, method of thrombosis prophylaxis, transfusion requirement, incidental postoperative hemorrhage, septic complications, and all other postoperative complications were recorded. Perioperative blood loss was affected with the use of tranexamic acid but not with the use of drainage (p = 0.94). Patients without the use of drain showed a tendency of lower transfusion requirement (p = 0.08). There was no correlation between any complications and the use of drainage. In accordance with published results the authors conclude that the routine use of suction drainage during elective hip arthroplasty is not definitely necessary. Orv. Hetil., 2016, 157(29), 1171-1176.

  17. Effect of suction and blowing on boundary-layer transition

    NASA Technical Reports Server (NTRS)

    Saric, W. S.; Reed, H. L.

    1983-01-01

    The effects of wall blowing and suction on boundary-layer stability and transition are studied on a flat plate. Titanium panels, in which 0.063 mm diameter holes were drilled on 0.635 mm centers, are inserted on the plate. Suction level and distribution are variable. Disturbances are introduced by means of a vibrating ribbon and measurements of both mean-flow and disturbance-flow velocities are made with a hot wire. Disturbance amplitudes are measured as a function of Reynolds number, frequency, and suction characteristics and compared with the previous Dynapore results of Reynolds and Saric. Transition measurements under natural and forced conditions are also made. The stabilizing effects of suction are documented. It is also shown that very high local flow rates through the suction holes (which approach a hole Reynolds number of 300) do not destabilize the flow. On the other hand, weak blowing lowers the transition Reynolds number but is found not to cause serious problems.

  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.

  19. 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 ...