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Sample records for affect fish reproduction

  1. Prey selectivity affects reproductive success of a corallivorous reef fish.

    PubMed

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

    2013-06-01

    Most animals consume a narrower range of food resources than is potentially available in the environment, but the underlying basis for these preferences is often poorly understood. Foraging theory predicts that prey selection should represent a trade-off between prey preferences based on nutritional value and prey availability. That is, species should consume preferred prey when available, but select less preferred prey when preferred prey is rare. We employed both field observation and laboratory experiments to examine the relationship between prey selection and preferences in the obligate coral-feeding filefish, Oxymonacanthus longirostris. To determine the drivers of prey selection, we experimentally established prey preferences in choice arenas and tested the consequences of prey preferences for key fitness-related parameters. Field studies showed that individuals fed almost exclusively on live corals from the genus Acropora. While diet was dominated by the most abundant species, Acropora nobilis, fish appeared to preferentially select rarer acroporids, such as A. millepora and A. hyacinthus. Prey choice experiments confirmed strong preferences for these corals, suggesting that field consumption is constrained by availability. In a longer-term feeding experiment, reproductive pairs fed on non-preferred corals exhibited dramatic reductions to body weight, and in hepatic and gonad condition, compared with those fed preferred corals. The majority of pairs fed preferred corals spawned frequently, while no spawning was observed for any pairs fed a non-preferred species of coral. These experiments suggest that fish distinguish between available corals based on their intrinsic value as prey, that reproductive success is dependent on the presence of particular coral species, and that differential loss of preferred corals could have serious consequences for the population success of these dietary specialists.

  2. A survey of Canadian mechanical pulp and paper mill effluents: insights concerning the potential to affect fish reproduction.

    PubMed

    Kovacs, Tibor G; Martel, Pierre H; O'Connor, Brian I; Hewitt, L Mark; Parrott, Joanne L; McMaster, Mark E; MacLatchy, Deborah L; Van Der Kraak, Glen J; Van Den Heuvel, Michael R

    2013-01-01

    Building on breakthroughs recently made at kraft mills, a survey of mechanical pulp and paper mill effluents was undertaken to gain insights concerning potential effects on fish reproduction. Effluents from seven Canadian mills were characterized chemically for conventional parameters such as biochemical oxygen demand (BOD) and total suspended solids (TSS). Each sample was further subjected to solvent extraction followed by gas chromatographic separation for the determination of resin/fatty acids and for the estimation of a gas chromatography (GC) profile index. Each mill effluent was assessed for the potential to affect fish reproduction in the laboratory using a five day adult fathead minnow (Pimephales promelas) egg production bioassay with exposures to 100% effluent. The seven effluents were found to have substantial variation both in terms of chemical characterization and effects on fish reproduction. Temporal variations were also noted in effluent quality at mills sampled on different occasions. Similar to what has been observed for kraft mills, a general trend of greater reductions in egg production caused by effluents with greater BOD concentrations and GC profile indices was noted. Effluents with BOD > 25 mg/L and GC Profile indices >5.0 caused a complete cessation of egg production. At the same time, about half of the total effluents sampled had BOD < 25 mg/L and GC profile indices <5.0 and caused no significant effects on egg production, suggesting these values may be useful as effluent quality targets for mechanical pulp and paper mills. However, 3 out of 14 effluents sampled had BOD < 25 mg/L and GC profile indices <5.0 and caused significant reductions in egg production. The reason(s) for reproductive effects caused by such effluents is presently unclear. The effluent quality parameters considered in this study may require further refinement to address their utility in predicting the adverse reproductive effects induced by effluents from mechanical

  3. Castration affects reproductive but not aggressive behavior in a cichlid fish.

    PubMed

    Almeida, Olinda; Canário, Adelino V M; Oliveira, Rui F

    2014-10-01

    Gonads are the main source of sex steroids, which have been implicated in the regulation of sexually differentiated behavior, such as reproductive and aggressive displays. In the Mozambique tilapia (Oreochromis mossambicus) territorial males have higher androgen levels than non-territorials, express reproductive behavior and use a urine-borne pheromone to signal their social status towards conspecifics. Here we investigated the effects of gonadectomy on the circulating levels of androgens and cortisol, and on the expression of aggressive and reproductive behavior (nest building, courtship behavior, and nuptial coloration). Males were either castrated, urine bladder damaged, or sham-operated and visually exposed to a group of females during 8 consecutive days and subsequently to a male on day 9. The urine bladder damaged treatment was included in the experimental design because a full castration procedure in this species causes quite often damage to the urine bladder. Gonadectomy lowers dramatically the circulating levels of androgens measured at 4 and 8days post-castration and abolishes the expression of nest building, courtship behavior and nuptial coloration, but has no effect on the expression of aggressive behavior. These results confirm the gonads as the main source of androgens in this species and show that androgens are necessary for the expression of reproductive behaviors. However, the expression of aggressive behavior seems to be decoupled from gonadal steroids, namely androgens, suggesting the action of independent central mechanisms.

  4. Evaluating the potential of effluent extracts from pulp and paper mills in Canada, Brazil, and New Zealand to affect fish reproduction: Estrogenic effects in fish.

    PubMed

    Orrego, Rodrigo; Milestone, Craig B; Hewitt, L Mark; Guchardi, John; Heid-Furley, Tatiana; Slade, Alison; MacLatchy, Deborah L; Holdway, Douglas

    2016-11-03

    The authors examined the potential of pulp mill effluent from pulp-producing countries (Canada, Brazil, New Zealand) to affect fish reproduction. Specifically, the estrogenic effects in juvenile rainbow trout (Oncorhynchus mykiss) pulse-exposed to 11 different mill effluent extracts (intraperitoneal injections of solid-phase extraction-dichloromethane nonpolar fraction). The results indicated that effluent extracts were estrogenic in juvenile trout irrespective of the gender, as reflected by increasing level of plasma vitellogenin (VTG; Brazil > New Zealand > Canada). Despite the high variability observed among mills, differences in VTG levels were related to the type of mill process (kraft > elementary chlorine-free kraft > thermomechanical pulping). Moreover, effluent treatments did not appear to significantly decrease VTG induction. A consistent estrogenic effect was observed in those mills that process a combination of feedstocks (softwood and hardwood), with the highest increase in VTG related to eucalyptus feedstock. The results demonstrate significant estrogenic effects of pulp mill effluents on chronically exposed juvenile trout, suggesting that in vivo metabolic activation of precursors is necessary to cause the observed increases in VTG levels. This molecular estrogenic response provides a useful starting point for predicting population-level impacts through the adverse outcome pathway methodology. Environ Toxicol Chem 2016;9999:1-9. © 2016 SETAC.

  5. Breeding resource distribution affects selection gradients on male phenotypic traits: experimental study on lifetime reproductive success in the bitterling fish (Rhodeus amarus).

    PubMed

    Reichard, Martin; Ondracková, Markéta; Bryjová, Anna; Smith, Carl; Bryja, Josef

    2009-02-01

    The spatial distribution of breeding resources can have pronounced demographic and evolutionary consequences. We used 20 experimental groups of the bitterling (Rhodeus amarus), an annual fish with a promiscuous, resource-based mating system, and extended breeding season to investigate how the spatial distribution (clumped or regular) of bitterling oviposition sites (live freshwater mussels) affected offspring production, variation in reproductive success, and directional selection on phenotypic traits over their entire reproductive lifetime. We did not detect any effect of resource distribution on offspring production or variation in reproductive success among individual fish, although variation between replicates was higher with a clumped distribution. This finding is discussed with regard to the incidence of alternative mating behaviors (sneaking) within the limitations imposed by our experimental design. Breeding resource distribution had a significant effect on selection on male phenotypic traits. Stronger directional selection on traits associated with intrasexual competition for fertilizations, gonad mass (an indicator of sperm competition), and the extent of red, carotenoid-based pigment in the iris (an index of dominance status), was detected with a clumped resource distribution. With a regular resource distribution, a stronger positive selection on male body size was detected. We discuss the implications of our results for natural populations.

  6. Fish reproductive guilds downstream of dams.

    PubMed

    Vasconcelos, L P; Alves, D C; Gomes, L C

    2014-11-01

    Fish reproductive guilds were used to evaluate the responses of species with different reproductive strategies during two different periods of post-dam construction. The data used for the comparisons were collected in the upper Paraná River floodplain (Brazil), downstream of the Porto Primavera dam, 2 and 10 years after impoundment. The abundance (catch per unit effort, CPUE), species richness, evenness and structure of communities, all within reproductive guilds, were used to test the hypothesis that these metrics vary spatially and temporally. The influence of damming on species structure and the diversity of fish reproductive guilds varied spatiotemporally, and species with opportunistic reproductive strategies tended to be less affected. Conversely, long-distance migratory species responded more markedly to spatiotemporal variations, indicating that the ecosystem dynamics exert greater effects on populations of these species. Thus, the effects of a dam, even if attenuated, may extend over several years, especially downstream. This finding emphasizes the importance of maintaining large undammed tributaries downstream of reservoirs.

  7. Stress and fish reproduction: The roles of allostasis and hormesis

    USGS Publications Warehouse

    Schreck, C.B.

    2010-01-01

    This paper is a review of the effects of stress on reproduction in fishes. I hope to further the development of the concepts of allostasis and hormesis as relevant to understanding reproduction in general and in fish in particular. The main contentions I derive in this review are the following: Stressors affect fish reproduction in a variety of ways depending on the nature and severity of the stressor. The effects are transduced through a hormonal cascade initiated by perception of the stressor and involving the hypothalamus-pituitary-interrenal axis, the catecholamines, and also cytokines. Mounting a stress response and resisting a stressor is an energetically costly process, including costs associated with allostasis, attempting to reset homeostatic norms. Responses in emergency situations (e.g., being chased by a predator or a net) can be different from those where fish can cope (e.g., being in a more crowded environment) with a stressor, but both situations involve energy re-budgeting. Emergency responses happen in concert with the onset of energy limitations (e.g., the fish may not eat), while coping with allostatic overload can happen in a more energy-rich environment (e.g., the fish can continue to eat). Low levels of stress may have a positive effect on reproductive processes while greater stress has negative effects on fish reproduction. The concept of hormesis is a useful way to think about the effect of stressors on fish reproduction since responses can be nonmonotonal, often biphasic.

  8. The role of prolactin in fish reproduction.

    PubMed

    Whittington, Camilla M; Wilson, Anthony B

    2013-09-15

    Prolactin (PRL) has one of the broadest ranges of functions of any vertebrate hormone, and plays a critical role in regulating aspects of reproduction in widely divergent lineages. However, while PRL structure, mode of action and functions have been well-characterised in mammals, studies of other vertebrate lineages remain incomplete. As the most diverse group of vertebrates, fish offer a particularly valuable model system for the study of the evolution of reproductive endocrine function. Here, we review the current state of knowledge on the role of prolactin in fish reproduction, which extends to migration, reproductive development and cycling, brood care behaviour, pregnancy, and nutrient provisioning to young. We also highlight significant gaps in knowledge and advocate a specific bidirectional research methodology including both observational and manipulative experiments. Focusing research efforts towards the thorough characterisation of a restricted number of reproductively diverse fish models will help to provide the foundation necessary for a more explicitly evolutionary analysis of PRL function.

  9. Role of serotonin in fish reproduction

    PubMed Central

    Prasad, Parvathy; Ogawa, Satoshi; Parhar, Ishwar S.

    2015-01-01

    The neuroendocrine mechanism regulates reproduction through the hypothalamo-pituitary-gonadal (HPG) axis which is evolutionarily conserved in vertebrates. The HPG axis is regulated by a variety of internal as well as external factors. Serotonin, a monoamine neurotransmitter, is involved in a wide range of reproductive functions. In mammals, serotonin regulates sexual behaviors, gonadotropin release and gonadotropin-release hormone (GnRH) secretion. However, the serotonin system in teleost may also play unique role in the control of reproduction as the mechanism of reproductive control in teleosts is not always the same as in the mammalian models. In fish, the serotonin system is also regulated by natural environmental factors as well as chemical substances. In particular, selective serotonin reuptake inhibitors (SSRIs) are commonly detected as pharmaceutical contaminants in the natural environment. Those factors may influence fish reproductive functions via the serotonin system. This review summarizes the functional significance of serotonin in the teleosts reproduction. PMID:26097446

  10. Role of serotonin in fish reproduction.

    PubMed

    Prasad, Parvathy; Ogawa, Satoshi; Parhar, Ishwar S

    2015-01-01

    The neuroendocrine mechanism regulates reproduction through the hypothalamo-pituitary-gonadal (HPG) axis which is evolutionarily conserved in vertebrates. The HPG axis is regulated by a variety of internal as well as external factors. Serotonin, a monoamine neurotransmitter, is involved in a wide range of reproductive functions. In mammals, serotonin regulates sexual behaviors, gonadotropin release and gonadotropin-release hormone (GnRH) secretion. However, the serotonin system in teleost may also play unique role in the control of reproduction as the mechanism of reproductive control in teleosts is not always the same as in the mammalian models. In fish, the serotonin system is also regulated by natural environmental factors as well as chemical substances. In particular, selective serotonin reuptake inhibitors (SSRIs) are commonly detected as pharmaceutical contaminants in the natural environment. Those factors may influence fish reproductive functions via the serotonin system. This review summarizes the functional significance of serotonin in the teleosts reproduction.

  11. Mercury-induced reproductive impairment in fish.

    PubMed

    Crump, Kate L; Trudeau, Vance L

    2009-05-01

    Mercury is a potent neurotoxin, and increasing levels have led to concern for human and wildlife health in many regions of the world. During the past three decades, studies in fish have examined the effects of sublethal mercury exposure on a range of endpoints within the reproductive axis. Mercury studies have varied from highly concentrated aqueous exposures to ecologically relevant dietary exposures using levels comparable to those currently found in the environment. This review summarizes data from both laboratory and field studies supporting the hypothesis that mercury in the aquatic environment impacts the reproductive health of fish. The evidence presented suggests that the inhibitory effects of mercury on reproduction occur at multiple sites within the reproductive axis, including the hypothalamus, pituitary, and gonads. Accumulation of mercury in the fish brain has resulted in reduced neurosecretory material, hypothalamic neuron degeneration, and alterations in parameters of monoaminergic neurotransmission. At the level of the pituitary, mercury exposure has reduced and/or inactivated gonadotropin-secreting cells. Finally, studies have examined the effects of mercury on the reproductive organs and demonstrated a range of effects, including reductions in gonad size, circulating reproductive steroids, gamete production, and spawning success. Despite some variation between studies, there appears to be sufficient evidence from laboratory studies to link exposure to mercury with reproductive impairment in many fish species. Currently, the mechanisms underlying these effects are unknown; however, several physiological and cellular mechanisms are proposed within this review.

  12. Effects of Two Progestins, Norethindrone and Levonorgestrel, on Reproduction in a Marine Fish, Tautogolabrus adspersus

    EPA Science Inventory

    Endocrine-active pharmaceuticals that enter the aquatic environment through sewage effluent may have unintended impacts on reproduction in fish, which in turn may affect the sustainability of exposed populations. Laboratory experiments were conducted with the marine fish cunner (...

  13. Effects of Two Progestins, Norethindrone and Levonorgestrel, On Reproduction in a Marine Fish, Tautogolabrus adspersus.

    EPA Science Inventory

    Endocrine-active pharmaceuticals that enter the aquatic environment through sewage effluent may have unintended impacts on reproduction in fish, which in turn may affect the sustainability of exposed populations. Laboratory experiments were conducted with the marine fish cunner (...

  14. Increased CO2 stimulates reproduction in a coral reef fish.

    PubMed

    Miller, Gabrielle M; Watson, Sue-Ann; McCormick, Mark I; Munday, Philip L

    2013-10-01

    Ocean acidification is predicted to negatively impact the reproduction of many marine species, either by reducing fertilization success or diverting energy from reproductive effort. While recent studies have demonstrated how ocean acidification will affect larval and juvenile fishes, little is known about how increasing partial pressure of carbon dioxide (pCO(2)) and decreasing pH might affect reproduction in adult fishes. We investigated the effects of near-future levels of pCO(2) on the reproductive performance of the cinnamon anemonefish, Amphiprion melanopus, from the Great Barrier Reef, Australia. Breeding pairs were held under three CO(2) treatments [Current-day Control (430 μatm), Moderate (584 μatm) and High (1032 μatm)] for a 9-month period that included the summer breeding season. Unexpectedly, increased CO(2) dramatically stimulated breeding activity in this species of fish. Over twice as many pairs bred in the Moderate (67% of pairs) and High (55%) compared to the Control (27%) CO(2) treatment. Pairs in the High CO(2) group produced double the number of clutches per pair and 67% more eggs per clutch compared to the Moderate and Control groups. As a result, reproductive output in the High group was 82% higher than that in the Control group and 50% higher than that in the Moderate group. Despite the increase in reproductive activity, there was no difference in adult body condition among the three treatment groups. There was no significant difference in hatchling length between the treatment groups, but larvae from the High CO(2) group had smaller yolks than Controls. This study provides the first evidence of the potential effects of ocean acidification on key reproductive attributes of marine fishes and, contrary to expectations, demonstrates an initially stimulatory (hormetic) effect in response to increased pCO(2). However, any long-term consequences of increased reproductive effort on individuals or populations remain to be determined.

  15. Impacts of moonlight on fish reproduction.

    PubMed

    Ikegami, Taro; Takeuchi, Yuki; Hur, Sung-Pyo; Takemura, Akihiro

    2014-04-01

    The waxing and waning cycle of the moon is repeated at approximately 1-month intervals, and concomitant changes occur in the levels of moonlight and cueing signals detected by organisms on the earth. In the goldlined spinefoot Siganus guttatus, a spawner lunar-synchronized around the first quarter moon, periodic changes in moonlight are used to cue gonadal development and gamete release. Rearing of mature fish under artificial constant full moon and new moon conditions during the spawning season leads to disruption or delay of synchronous spawning around the predicted moon phase. Melatonin, an endogenous transducer of the environmental light/dark cycle, increases in the blood and in the pineal gland around the new moon period and decreases around the full moon period. In synchrony with melatonin fluctuation, melatonin receptor(s) mRNA abundance is higher during the new moon period than during the full moon. The melatonin/melatonin receptor system is likely affected by moonlight. Measurements of the expression patterns of clock genes in neural tissues demonstrate that Cryptochrome (Cry1 and Cry3) and Period (Per2) fluctuate with lunar periodicity, the former peaking in the medial part of the brain around the first quarter moon period, and the latter peaking in the pineal gland around the full moon. Some clock genes may respond to periodic changes in moon phase and appear to be involved in the generation of lunar-related rhythmicity in lunar spawners. Thus, some fish use moonlight-related periodicities as reliable information for synchronizing the timing of reproductive events.

  16. Great Lakes fish consumption and reproductive outcomes

    SciTech Connect

    Dar, E.

    1989-01-01

    This epidemiological investigation determined prenatal exposure to polychlorinated biphenyls (PCBs), through contaminated fish consumption, and ascertained reproductive outcomes. Green Bay, Wisconsin was chosen as the study site because it was known for its environmental contamination of PCBs. These chemicals are environmentally stable and persistent, and tend to bioaccumulate up the food chain, with highest levels found in predatory sport fish from Lake Michigan. The Green Bay area provided a population with potential PCB exposure from sport fish consumption. Accidental poisoning incidents showed detrimental reproductive effects of high dose PCB exposures. A Michigan study found significant effects on birth weight and gestational age when mothers consumed two sport fish meals per month. This study population was drawn from women during their first prenatal visit at two Green Bay clinics during a one year period. 1,112 participants completed a self-administered questionnaire. Maternal and cord blood samples were obtained for selected PCB serum analyses. Reproductive outcome measures were abstracted from hospital labor reports. Study results indicated that maternal consumption was correlated to maternal PCB serum levels. Regression techniques estimated significant exposure coefficients for subsets of two birth size parameters. Birth length was positively associated with PCB exposure in shorter mothers. Significant associations of PCB exposure and birth weight percentiles were estimated for two income groups in the urban residence/weight gain less than 34 pounds subset.

  17. Contrasting effects of ocean acidification on reproduction in reef fishes

    NASA Astrophysics Data System (ADS)

    Welch, Megan J.; Munday, Philip L.

    2016-06-01

    Differences in the sensitivity of marine species to ocean acidification will influence the structure of marine communities in the future. Reproduction is critical for individual and population success, yet is energetically expensive and could be adversely affected by rising CO2 levels in the ocean. We investigated the effects of projected future CO2 levels on reproductive output of two species of coral reef damselfish, Amphiprion percula and Acanthochromis polyacanthus. Adult breeding pairs were maintained at current-day control (446 μatm), moderate (652 μatm) or high CO2 (912 μatm) for a 9-month period that included the summer breeding season. The elevated CO2 treatments were consistent with CO2 levels projected by 2100 under moderate (RCP6) and high (RCP8) emission scenarios. Reproductive output increased in A. percula, with 45-75 % more egg clutches produced and a 47-56 % increase in the number of eggs per clutch in the two elevated CO2 treatments. In contrast, reproductive output decreased at high CO2 in Ac. polyacanthus, with approximately one-third as many clutches produced compared with controls. Egg survival was not affected by CO2 for A. percula, but was greater in elevated CO2 for Ac. polyacanthus. Hatching success was also greater for Ac. polyacanthus at elevated CO2, but there was no effect of CO2 treatments on offspring size. Despite the variation in reproductive output, body condition of adults did not differ between control and CO2 treatments in either species. Our results demonstrate different effects of high CO2 on fish reproduction, even among species within the same family. A greater understanding of the variation in effects of ocean acidification on reproductive performance is required to predict the consequences for future populations of marine organisms.

  18. Shoreline development and degradation of coastal fish reproduction habitats.

    PubMed

    Sundblad, Göran; Bergström, Ulf

    2014-12-01

    Coastal development has severely affected habitats and biodiversity during the last century, but quantitative estimates of the impacts are usually lacking. We utilize predictive habitat modeling and mapping of human pressures to estimate the cumulative long-term effects of coastal development in relation to fish habitats. Based on aerial photographs since the 1960s, shoreline development rates were estimated in the Stockholm archipelago in the Baltic Sea. By combining shoreline development rates with spatial predictions of fish reproduction habitats, we estimated annual habitat degradation rates for three of the most common coastal fish species, northern pike (Esox lucius), Eurasian perch (Perca fluviatilis) and roach (Rutilus rutilus). The results showed that shoreline constructions were concentrated to the reproduction habitats of these species. The estimated degradation rates, where a degraded habitat was defined as having ≥3 constructions per 100 m shoreline, were on average 0.5 % of available habitats per year and about 1 % in areas close to larger population centers. Approximately 40 % of available habitats were already degraded in 2005. These results provide an example of how many small construction projects over time may have a vast impact on coastal fish populations.

  19. Can Myxosporean parasites compromise fish and amphibian reproduction?

    PubMed Central

    Sitjà-Bobadilla, Ariadna

    2009-01-01

    Research into fish and amphibian reproduction has increased exponentially in recent years owing to the expansion of the aquaculture industry, the need to recover fishery populations, the impact of endocrine disruptors on the aquatic environment and the global decline of amphibian populations. This review focuses on a group of parasites, the Myxozoa, that affect fish and amphibian reproduction. Lists of the myxosporeans that specifically infect gonads are provided. Most of these are parasitic of freshwater hosts, and most amphibian cases are reported from testes. Sex specificity and sex reversal are discussed in relation to gonadal parasitism. The immune response of the fish to the infection is described, and the contribution of the immunoprivilege of gonads to host invasion is emphasized. The pathological effect of these parasites can be significant, especially in aquacultured broodstocks, on some occasions, leading to parasitic castration. Although myxosporean parasites are currently not very frequent in gonads, their impact could increase in the future owing to the transactions in the global market. Their easy release into the aquatic environment with spawning could make their spreading even more feasible. In the absence of commercial drugs or vaccines to treat and prevent these infections, there is an urgent need to develop specific, rapid and reliable diagnostic tools to control and manage animal movements. In addition, much effort is still to be made on deciphering the life cycle of these organisms, their invasion strategies and their immune evasion mechanisms. PMID:19474043

  20. Corticosteroids: Friends or foes of teleost fish reproduction?

    PubMed

    Milla, S; Wang, N; Mandiki, S N M; Kestemont, P

    2009-07-01

    Reproduction in vertebrates is controlled by the Hypothalamus-Pituitary-Gonad axis and the main hormone actions have been extensively described. Still, despite the scattered information in fish, accumulating evidence strongly indicates that corticosteroids play essential roles in reproductive mechanisms. An integrative approach is important for understanding these implications. Animal husbandry and physiological studies at molecular to organismal levels have revealed that these corticosteroids are regulators of fish reproductive processes. But their involvements appear strongly contrasted. Indeed, for both sexes, corticosteroids present either deleterious or positive effects on fish reproduction. In this review, the authors will attempt to gather and clarify the available information about these physiological involvements. The authors will also suggest future ways to prospect corticosteroid roles in fish reproduction.

  1. Effects of global warming on fish reproductive endocrine axis, with special emphasis in pejerrey Odontesthes bonariensis.

    PubMed

    Miranda, Leandro Andrés; Chalde, Tomás; Elisio, Mariano; Strüssmann, Carlos Augusto

    2013-10-01

    The ongoing of global warming trend has led to an increase in temperature of several water bodies. Reproduction in fish, compared with other physiological processes, only occurs in a bounded temperature range; therefore, small changes in water temperature could significantly affect this process. This review provides evidence that fish reproduction may be directly affected by further global warming and that abnormal high water temperature impairs the expression of important genes throughout the brain-pituitary-gonad axis. In all fishes studied, gonads seem to be the organ more readily damaged by heat treatments through the inhibition of the gene expression and subsequent synthesis of different gonadal steroidogenic enzymes. In view of the feedback role of sex steroids upon the synthesis and release of GnRH and GtHs in fish, it is possible that the inhibition observed at brain and pituitary levels in treated fish is consequence of the sharp decrease in plasma steroids levels. Results of in vitro studies on the inhibition of pejerrey gonad aromatase expression by high temperature corroborate that ovary functions are directly disrupted by high temperature independently of the brain-pituitary axis. For the reproductive responses obtained in laboratory fish studies, it is plausible to predict changes in the timing and magnitude of reproductive activity or even the total failure of spawning season may occur in warm years, reducing annual reproductive output and affecting future populations.

  2. Environmental color affects Nile tilapia reproduction.

    PubMed

    Volpato, G L; Duarte, C R A; Luchiari, A C

    2004-04-01

    We investigated the effects of environmental color on the reproductive behavior of Nile tilapia, Oreochromis niloticus. Two environmental colors were tested by covering the aquarium (60 x 60 x 40 cm) with white (12 groups) or blue (13 groups) cellophane and observing reproductive behavior in groups of 2 males (10.27 +/- 0.45 cm) and 3 females (10.78 +/- 0.45 cm) each. After assignment to the respective environmental color (similar luminosity = 100 to 120 Lux), the animals were observed until reproduction (identified by eggs in the female's mouth) or up to 10 days after the first nest building. Photoperiod was from 6:00 h to 18:00 h every day. Food was offered in excess once a day and water quality was similar among aquaria. Daily observations were made at 8:00, 11:00, 14:00 and 17:00 h regarding: a) latency to the first nest, b) number of nests, c) gravel weight removed (the male excavates the nest in the bottom of the aquarium), d) nest area, and e) mouthbrooding incubation (indication of reproduction). The proportion of reproducing fish was significantly higher (6 of 13) in the group exposed to the blue color compared the group exposed to the white color (1 of 12; Goodman's test of proportions). Moreover, males under blue light removed significantly larger masses of gravel (blue = 310.70 +/- 343.50 g > white = 130.38 +/- 102.70 g; P = 0.01) and constructed wider nests (blue = 207.93 +/- 207.80 cm(2) > white = 97.68 +/- 70.64 cm(2); P = 0.03) than the control (white). The other parameters did not differ significantly between light conditions. We concluded that reproduction in the presence of blue light was more frequent and intense than in the presence of white light.

  3. May organic pollutants affect fish populations in the North Sea?

    PubMed

    Hylland, Ketil; Beyer, Jonny; Berntssen, Marc; Klungsøyr, Jarle; Lang, Thomas; Balk, Lennart

    2006-01-08

    The North Sea is a highly productive area with large fish populations that have been extensively harvested over the past century. North Sea fisheries remain important to the surrounding countries despite declining fish stocks over the past decades. The main reason for declining fish stocks is nearly certainly overfishing, but other environmental pressures also affect fish populations, such as eutrophication, climate change, and exposure to metals and organic pollutants, including polyaromatic hydrocarbons (PAHs), alkylphenols, and organochlorine compounds. There are three main sources of organic pollutants in the North Sea: atmospheric, land-based sources, and inputs from offshore gas and oil installations. All three sources contribute to elevated concentrations of organic pollutants in the North Sea compared to the Norwegian Sea. There is evidence that chlorinated organic contaminants were present in sufficiently high concentrations in the southern North Sea two decades ago, to alter embryonal development in fish. The results from extensive, long-term monitoring programs show that some diseases decreased whereas other increased in the southern North Sea and that, among other factors, contaminants may play a role in the temporal changes recorded in disease prevalence. Recent studies demonstrated that components in offshore effluents may affect fish reproduction and that tissues of fish near oil rigs are structurally different to tissues of fish from reference areas. Data on effluents from offshore activities have recently become available through an international workshop (BECPELAG) and follow-up studies.

  4. Insulin-like growth factors and fish reproduction.

    PubMed

    Reinecke, Manfred

    2010-04-01

    Knowledge of fish reproduction is of high relevance to basic fish biology and comparative evolution. Furthermore, fish are excellent biomedical models, and the impact of aquaculture on worldwide food production is steadily increasing. Consequently, research on fish reproduction and the potential modes of its manipulation has become more and more important. Reproduction in fish is regulated by the integration of endogenous neuroendocrine (gonadotropins), endocrine, and autocrine/paracrine signals with exogenous (environmental) factors. The main endocrine regulators of gonadal sex differentiation and function are steroid hormones. However, recent studies suggest that other hormones are also involved. Most prominent among these hormones are the insulin-like growth factors (Igfs), i.e., Igf1, Igf2, and, most recently, Igf3. Thus, the present review deals with the expression patterns and potential physiological functions of Igf1 and Igf2 in male and female gonads. It further considers the potential involvement of growth hormone (Gh) and balances the reasons for endocrine vs. autocrine/paracrine action of the Igfs on the gonads of fish. Finally, this review discusses the early and late development of gonadal Igf1 and Igf2 and whether they are targets of endocrine-disrupting compounds. Future topics for novel research investigation on Igfs and fish reproduction are presented.

  5. Selenium and mercury have a synergistic negative effect on fish reproduction.

    PubMed

    Penglase, S; Hamre, K; Ellingsen, S

    2014-04-01

    Selenium (Se) can reduce the negative impacts of mercury (Hg) toxicity on growth and survival, but little is known about how these two elements interact in reproduction. In the following study we explored the effects of organic Hg and Se on the growth, survival and reproduction of female zebrafish (Danio rerio). Fish were fed one of four diets from 73 until 226 dpf in a 2 × 2 factorial design, using selenomethionine (SeMet) and methylmercury (MeHg) as the Se and Hg sources, respectively. Each diet contained Se at either requirement (0.7 mg Se/kg DM) or elevated levels (10 mg Se/kgDM), and Hg at either low (0.05 mg Hg/kg DM) or elevated (12 mg Hg/kg DM) levels. Between 151 and 206 dpf the female fish were pairwise crossed against untreated male fish and the mating success, fecundity, embryo survival, and subsequent overall reproductive success were measured. Elevated dietary Se reduced Hg levels in both the adult fish and their eggs. Elevated dietary Hg and Se increased egg Se levels to a greater extent than when dietary Se was elevated alone. At elevated maternal intake levels, egg concentrations of Se and Hg reflected the maternal dietary levels and not the body burdens of the adult fish. Elevated dietary Hg reduced the growth and survival of female fish, but these effects were largely prevented with elevated dietary Se. Elevated dietary Se alone did not affect fish growth or survival. Compared to other treatments, elevated dietary Hg alone increased both mating and overall reproductive success with <100 days of exposure, but decreased these parameters with >100 days exposure. Elevated dietary Se decreased fecundity, embryo survival, and overall reproductive success. The combination of elevated Se and Hg had a synergistic negative effect on all aspects of fish reproduction compared to those groups fed elevated levels of either Se or Hg. Overall the data demonstrate that while increased dietary Se may reduce adverse effects of Hg on the growth and survival in

  6. Solar activity affects avian timing of reproduction

    PubMed Central

    Visser, Marcel E.; Sanz, Juan José

    2009-01-01

    Avian timing of reproduction is strongly affected by ambient temperature. Here we show that there is an additional effect of sunspots on laying date, from five long-term population studies of great and blue tits (Parus major and Cyanistes caeruleus), demonstrating for the first time that solar activity not only has an effect on population numbers but that it also affects the timing of animal behaviour. This effect is statistically independent of ambient temperature. In years with few sunspots, birds initiate laying late while they are often early in years with many sunspots. The sunspot effect may be owing to a crucial difference between the method of temperature measurements by meteorological stations (in the shade) and the temperatures experienced by the birds. A better understanding of the impact of all the thermal components of weather on the phenology of ecosystems is essential when predicting their responses to climate change. PMID:19574283

  7. Validation of a Fish Short-term Reproduction Assay

    EPA Science Inventory

    The Fish Short-term Reproduction Assay is an in vivo assay conducted with fathead minnows and is designed to detect changes in spawning, gross morphology, histopathology, and specific biochemical endpoints that reflect disturbances in the hypothalamic-pituitary-gonadal (HPG) axis...

  8. Evaluating the Effects of the Kingston Fly Ash Release on Fish Reproduction: Spring 2009 - 2010 Studies

    SciTech Connect

    Greeley Jr, Mark Stephen; Adams, Marshall; McCracken, Kitty

    2012-05-01

    the ability of individuals within a population to reproduce. Reproduction is thus generally considered to be the most critical life function affected by environmental contamination. From a regulatory perspective, the issue of potential contaminant-related effects on fish reproduction from the Kingston fly ash spill has particular significance because the growth and propagation of fish and other aquatic life is a specific classified use of the affected river systems. To address the potential effects of fly ash from the Kingston spill on the reproductive health of exposed fish populations, ORNL has undertaken a series of studies in collaboration with TVA that include: (1) a combined field study of metal bioaccumulation in ovaries and other fish tissues (Adams and others 2012) and the reproductive condition of sentinel fish species in reaches of the Emory and Clinch Rivers affected by the fly ash spill (the current report); (2) laboratory tests of the potential toxicity of fly ash from the spill area on fish embryonic and larval development (Greeley and others 2012); (3) additional laboratory experimentation focused on the potential effects of long-term exposures to fly ash on fish survival and reproductive competence (unpublished); and (4) a combined field and laboratory study examining the in vitro developmental success of embryos and larvae obtained from fish exposed in vivo for over two years to fly ash in the Emory and Clinch Rivers (unpublished). The current report focuses on the reproductive condition of adult female fish in reaches of the Emory and Clinch Rivers influenced by the fly ash spill at the beginning of the spring 2009 breeding season - the first breeding season immediately following the fly ash release - and during the subsequent spring 2010 breeding season. Data generated from this and related reproductive/early life stage studies provide direct input to ecological risk assessment efforts and complement and support other phases of the overall

  9. Reproductive biology of freshwater fishes from the Venezuelan floodplains.

    PubMed

    Guerrero, H Y; Cardillo, E; Poleo, G; Marcano, D

    2009-03-01

    This review describes the endocrine changes that occur during the annual reproductive cycle of Pygocentrus cariba, Pimelodus blochii, and Oxydoras sifontesi and their relationships with the environmental characteristics of Venezuelan floodplains. Most reproductive studies of teleosts have focused on changes that occur during annual cycles in temperate species but, in tropical fish, this has been examined less frequently. P. cariba, P. blochii, and O. sifontesi are seasonal breeders widely distributed along the Orinoco River. Under natural conditions they have an annual gonadal cycle closely related to changes in the annual hydrology cycle of the Orinoco River which defines two seasons on the floodplain: inundation and isolation. The reproductive cycle of these species seems to be controlled by cues from the external environment. Relevant data about gonadal maturation, for example gonadosomatic index and sexual hormones secretion, are contrasted. The role of catecholamines in neuroendocrine control of the reproductive axis is also considered in this work.

  10. Hyperoxia Elevates Adrenic Acid Peroxidation in Marine Fish and Is Associated with Reproductive Pheromone Mediators

    PubMed Central

    Chung, Ming Long Sirius; Galano, Jean-Marie; Oger, Camille; Durand, Thierry; Lee, Jetty Chung-Yung

    2015-01-01

    The development of oxidative stress in the marine ecosystem is a concurring concern in fish reproductive behavior. Marine fish being rich in polyunsaturated fatty acids (PUFA) are precursors of prostaglandin pheromone mediators but also vulnerable to lipid peroxidation. It is yet to be determined if hypoxia or hyperoxia environment, a cumulative effect in the marine ecosystem affect pheromone mediators in fish, and to understand if this is associated with the generation of oxidized lipid products of PUFA. Novel oxidized lipid metabolites, isoprostanoids (15-F2t-isoprostane, 7(RS)-7-F2t-dihomo-isoprostane, 17(RS)-17-F2t-dihomo-isoprostane, 8-F3t-isoprostane, 4(RS)-4-F4t-neuroprostane, 10-F4t-neuroprostane), isofuranoids (isofurans, 10-epi-17(RS)-SC-Δ15-11-dihomo-isofuran and neurofurans), hydroxyeicosatetraenoic acids and resolvins, PUFA (arachidonic, adrenic, eicosapentaenoic and docosahexaenoic acids) and prostaglandin pheromone mediators in fish muscle were determined in marine male and female fish muscles before and after interaction in a hypoxia or hyperoxia environment. Reproductive behaviors were also assessed. Our study showed oxidized lipid metabolites of arachidonic, eicosapentaenoic, and docosahexaenoic acids were not influenced by hypoxia and hyperoxia exposure in the fishes and no gender differences were found. However, adrenic acid and its oxidized products, 17(RS)-17-F2t-dihomo-isoprostane and 10-epi-17(RS)-SC-Δ15-11-dihomo-isofuran showed strong correspondence with male fish pheromone mediators and reproductive behavior when under oxidative stress especially, hyperoxia. The occurrence of hypoxia and hyperoxia in the marine ecosystem may not be detrimental to marine fish and instead presents as being beneficial in reproductive behavior. PMID:25874920

  11. Reproductive and developmental toxicity of dioxin in fish.

    PubMed

    King-Heiden, Tisha C; Mehta, Vatsal; Xiong, Kong M; Lanham, Kevin A; Antkiewicz, Dagmara S; Ganser, Alissa; Heideman, Warren; Peterson, Richard E

    2012-05-06

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD or dioxin) is a global environmental contaminant and the prototypical ligand for investigating aryl hydrocarbon receptor (AHR)-mediated toxicity. Environmental exposure to TCDD results in developmental and reproductive toxicity in fish, birds and mammals. To resolve the ecotoxicological relevance and human health risks posed by exposure to dioxin-like AHR agonists, a vertebrate model is needed that allows for toxicity studies at various levels of biological organization, assesses adverse reproductive and developmental effects and establishes appropriate integrative correlations between different levels of effects. Here we describe the reproductive and developmental toxicity of TCDD in feral fish species and summarize how using the zebrafish model to investigate TCDD toxicity has enabled us to characterize the AHR signaling in fish and to better understand how dioxin-like chemicals induce toxicity. We propose that such studies can be used to predict the risks that AHR ligands pose to feral fish populations and provide a platform for integrating risk assessments for both ecologically relevant organisms and humans.

  12. Reproductive and Developmental Toxicity of Dioxin in Fish1

    PubMed Central

    King-Heiden, Tisha C.; Mehta, Vatsal; Xiong, Kong M.; Lanham, Kevin A.; Antkiewicz, Dagmara S.; Ganser, Alissa; Heideman, Warren

    2011-01-01

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD or dioxin) is a global environmental contaminant and the prototypical ligand for investigating aryl hydrocarbon receptor (AHR)-mediated toxicity. Environmental exposure to TCDD results in developmental and reproductive toxicity in fish, birds and mammals. To resolve the ecotoxicological relevance and human health risks posed by exposure to dioxin-like AHR agonists, a vertebrate model is needed that allows for toxicity studies at various levels of biological organization, assesses adverse reproductive and developmental effects and establishes appropriate integrative correlations between different levels of effects. Here we describe the reproductive and developmental toxicity of TCDD in feral fish species and summarize how using the zebrafish model to investigate TCDD toxicity has enabled us to characterize the AHR signaling in fish and to better understand how dioxin-like chemicals induce toxicity. We propose that such studies can be used to predict the risks that AHR ligands pose to feral fish populations and provide a platform for integrating risk assessments for both ecologically relevant organisms and humans. PMID:21958697

  13. Effects of the UV filter benzophenone-2 on reproduction in fish

    SciTech Connect

    Weisbrod, Christin J.; Kunz, Petra Y.; Zenker, Armin K.; Fent, Karl

    2007-12-15

    The UV filter benzophenone-2 (BP-2) is largely used in personal care products such as cosmetics and in numerous other materials for UV protection. Like other UV filters, BP-2 has been found to be estrogenic in vitro and in vivo, but potential effects on reproduction of fish are unknown. In this study, we evaluate whether BP-2 affects important reproductive parameters such as fecundity, gametogenesis and secondary sex characteristics. After a pre-exposure period of 19 days, reproductively mature fathead minnows (Pimephales promelas) were exposed to 0.002, 0.1, 1.2, 5.0 and 9.7 mg/L BP-2 for 15 days. BP-2 was accumulated in fish up to 3.1 {mu}g/g body weight. In males, a dose-dependent vitellogenin induction and decrease in the number of nuptial tubercles occurred. Moreover, significant dose-related effects on gonads of male and female fish were observed. At concentrations of 1.2 mg/L and higher, spermatocyte and oocyte development was significantly inhibited in male and female fish, respectively. Testes of exposed males had much fewer spermatocytes and ovaries of exposed females had much fewer mature and more atretic follicles. Reproduction was negatively affected in a dose-dependent manner with a decrease in egg production at 5.0 mg/L and a complete cessation of spawning activity at 9.7 mg/L BP-2. Our findings show significant estrogenic effects of the common UV filter BP-2 on vitellogenin induction, secondary sex characteristics, gonadal development, and reproduction in fish.

  14. Hypoxia causes transgenerational impairments in reproduction of fish

    PubMed Central

    Wang, Simon Yuan; Lau, Karen; Lai, Keng-Po; Zhang, Jiang-Wen; Tse, Anna Chung-Kwan; Li, Jing-Woei; Tong, Yin; Chan, Ting-Fung; Wong, Chris Kong-Chu; Chiu, Jill Man-Ying; Au, Doris Wai-Ting; Wong, Alice Sze-Tsai; Kong, Richard Yuen-Chong; Wu, Rudolf Shiu-Sun

    2016-01-01

    Hypoxia is amongst the most widespread and pressing problems in aquatic environments. Here we demonstrate that fish (Oryzias melastigma) exposed to hypoxia show reproductive impairments (retarded gonad development, decrease in sperm count and sperm motility) in F1 and F2 generations despite these progenies (and their germ cells) having never been exposed to hypoxia. We further show that the observed transgenerational reproductive impairments are associated with a differential methylation pattern of specific genes in sperm of both F0 and F2 coupled with relevant transcriptomic and proteomic alterations, which may impair spermatogenesis. The discovered transgenerational and epigenetic effects suggest that hypoxia might pose a dramatic and long-lasting threat to the sustainability of fish populations. Because the genes regulating spermatogenesis and epigenetic modifications are highly conserved among vertebrates, these results may also shed light on the potential transgenerational effects of hypoxia on other vertebrates, including humans. PMID:27373813

  15. Factors affecting the reproductive success of dominant male meerkats.

    PubMed

    Spong, Göran F; Hodge, Sarah J; Young, Andrew J; Clutton-Brock, Tim H

    2008-05-01

    Identifying traits that affect the reproductive success of individuals is fundamental for our understanding of evolutionary processes. In cooperative breeders, a dominant male typically restricts mating access to the dominant female for extended periods, resulting in pronounced variation in reproductive success among males. This may result in strong selection for traits that increase the likelihood of dominance acquisition, dominance retention and reproductive rates while dominant. However, despite considerable research on reproductive skew, few studies have explored the factors that influence these three processes among males in cooperative species. Here we use genetic, behavioural and demographic data to investigate the factors affecting reproductive success in dominant male meerkats (Suricata suricatta). Our data show that dominant males sire the majority of all offspring surviving to 1 year. A male's likelihood of becoming dominant is strongly influenced by age, but not by weight. Tenure length and reproductive rate, both important components of dominant male reproductive success, are largely affected by group size and composition, rather than individual traits. Dominant males in large groups have longer tenures, but after this effect is controlled, male tenure length also correlates negatively to the number of adult females in the group. Male reproductive rate also declines as the number of intra- and extra-group competitors increases. As the time spent in the dominant position and reproductive rate while dominant explain > 80% of the total variance in reproductive success, group composition thus has major implications for male reproductive success.

  16. Facultative symbiont infections affect aphid reproduction.

    PubMed

    Simon, Jean-Christophe; Boutin, Sébastien; Tsuchida, Tsutomu; Koga, Ryuichi; Le Gallic, Jean-François; Frantz, Adrien; Outreman, Yannick; Fukatsu, Takema

    2011-01-01

    Some bacterial symbionts alter their hosts reproduction through various mechanisms that enhance their transmission in the host population. In addition to its obligatory symbiont Buchnera aphidicola, the pea aphid Acyrthosiphon pisum harbors several facultative symbionts influencing several aspects of host ecology. Aphids reproduce by cyclical parthenogenesis whereby clonal and sexual reproduction alternate within the annual life cycle. Many species, including the pea aphid, also show variation in their reproductive mode at the population level, with some lineages reproducing by cyclical parthenogenesis and others by permanent parthenogenesis. While the role of facultative symbionts has been well studied during the parthenogenetic phase of their aphid hosts, very little is known on their possible influence during the sexual phase. Here we investigated whether facultative symbionts modulate the capacity to produce sexual forms in various genetic backgrounds of the pea aphid with controlled symbiont composition and also in different aphid genotypes from natural populations with previously characterized infection status and reproductive mode. We found that most facultative symbionts exhibited detrimental effects on their hosts fitness under sex-inducing conditions in comparison with the reference lines. We also showed that the loss of sexual phase in permanently parthenogenetic lineages of A. pisum was not explained by facultative symbionts. Finally, we demonstrated that Spiroplasma infection annihilated the production of males in the host progeny by inducing a male-killing phenotype, an unexpected result for organisms such as aphids that reproduce primarily through clonal reproduction.

  17. Reproductive consequences of exposure to waterborne phytoestrogens in male fighting fish Betta splendens.

    PubMed

    Stevenson, Louise M; Brown, Alexandria C; Montgomery, Tracy M; Clotfelter, Ethan D

    2011-04-01

    Phytoestrogens are plant compounds that can act as endocrine disruptors in vertebrates. Biologically active levels of phytoestrogens have been found in aquatic habitats near wood pulp and paper mills, biofuel manufacturing plants, sewage-treatment plants, and agricultural fields. Phytoestrogens are known to cause hormonal and gonadal changes in male fish, but few studies have connected these effects to outcomes relevant to reproductive success. In one experiment, we exposed sexually mature male fighting fish Betta splendens to environmentally relevant (1 μg L(-1)) and pharmacological concentrations (1000 μg L(-1)) of the phytoestrogen genistein as well as to a positive control of waterborne 17β-estradiol (E2; 1 μg L(-1)), and a negative control of untreated water. In a second experiment, we exposed male B. splendens to environmentally relevant concentrations (1 μg L(-1)) of genistein and β-sitosterol singly and in combination as well as to the positive and negative controls. All exposures were 21 days in duration. We measured sex-steroid hormone levels, gonadosomatic index (GSI), sperm concentration and motility, and fertilization success in these fish. We found that exposure to genistein did not affect circulating levels of the androgen 11-ketotestosterone or the estrogen E2 relative to negative-control fish. We also found that neither of the compounds nor their mixture affected GSI, sperm concentration or motility, or fertilization success in exposed fish relative to negative-control fish. However, fish exposed to phytoestrogens showed some evidence of fewer but more motile sperm than fish exposed to the positive control E2. We conclude that sexually mature male B. splendens are relatively immune to reproductive impairments from short-term exposure to waterborne phytoestrogens.

  18. The glucocorticoid stress response is attenuated but unrelated to reproductive investment during parental care in a teleost fish.

    PubMed

    O'Connor, Constance M; Yick, Claire Y; Gilmour, Kathleen M; Van Der Kraak, Glen; Cooke, Steven J

    2011-01-15

    We investigated whether circulating glucocorticoids and androgens are correlated with reproductive investment in smallmouth bass (Micropterus dolomieu), a teleost fish with sole paternal care. Circulating cortisol and androgens prior to and 25 min following a standardized 3 min emersion stressor were quantified for non-reproductive and parental fish across the parental care period. To experimentally investigate the influence of reproductive investment on endocrine parameters, we manipulated brood size (reduced, enlarged, sham-treated, or unmanipulated) 24h prior to sampling parental fish. We predicted that fish guarding offspring would exhibit increased androgens and baseline cortisol levels, and an attenuated cortisol response to the stressor when compared with non-reproductive individuals. We further predicted that these effects would scale with reproductive investment. As predicted, parental care-providing fish exhibited lower post-stress plasma cortisol concentrations than non-reproductive fish. This difference was strongest early during parental care. However, no differences in baseline or post-stress cortisol concentrations were detected among parents guarding offspring with varying brood sizes. There was, however, a trend for parental fish to exhibit an increased cortisol response following brood manipulation, regardless of the direction of change in brood size, a response that likely reflected disturbance. No differences were found in baseline cortisol concentrations. Circulating androgens were found to be highest during early parental care, and no differences were found among parents guarding manipulated broods. Collectively, these findings demonstrate that the endocrine stress response is affected by reproductive status, but the response in this model species does not appear to be scaled according to reproductive investment as predicted by life-history theory.

  19. [Advances in the study of neuroendocrinological regulation of kisspeptin in fish reproduction].

    PubMed

    Zhuo, Qi

    2013-10-01

    Kisspeptin, a key factor in the neuroendocrinological regulation of animal reproduction, is a peptide product encoded by kiss genes, which act as the natural ligand of GPR54. Over the last decade, multiple functional molecular forms of kisspeptin have been found in vertebrate species. In fish, the major molecular structural form is kisspeptin-10. The kisspeptin/GPR54 system has multiple important functions in reproduction. This review provides an overview of our current knowledge on kisspeptin and its role in regulating fish reproductive, including the distribution and location of kisspeptin neurons in the brain, the molecular polymorphism of fish kisspeptin, functional diversity, the molecular mechanism of fish reproductive regulation, and the molecular evolution of kisspeptin as well as the co-regulation of fish reproduction by kisspeptin and other functional molecules. Perspectives on the future of kisspeptin regulation in fish reproduction are also highlighted.

  20. The role of reproductive behavior in the conservation of fishes: examples from the Great Plains riverine fishes

    USGS Publications Warehouse

    Wildhaber, M.L.

    2006-01-01

    Recovery efforts for threatened and endangered fish species are hampered by lack of knowledge of their reproductive ecology. Habitat requirements and environmental stimuli necessary for reproduction are often unknown and vary widely among species. For Great Plains riverine fishes, this is often complicated by the high turbidity of the system in which the species occur, which precludes direct visual observation of behavior. Innovative methods for collectng behavioral data are required to better understand the conditions necessary for successful reproduction.

  1. Pharmaceuticals and personal care products: A critical review of the impacts on fish reproduction.

    PubMed

    Overturf, Matthew D; Anderson, Jordan C; Pandelides, Zacharias; Beyger, Lindsay; Holdway, Douglas A

    2015-07-01

    Research in environmental toxicology involving pharmaceuticals and personal care products (PPCPs) has increased greatly over the last 10-15 years. Much research has been focused on the endocrine-disrupting potential of PPCPs, as they relate to negative population impacts of aquatic organisms. This review assesses the current data on the reported effects of PPCPs on fish reproduction with an emphasis on fecundity, a predictor of population effects. Studies of both individual PPCPs and PPCP mixtures are presented. As the majority of individual PPCP studies reviewed demonstrate negative effects on fish fecundity, we relate these findings to detected surface water concentrations of these compounds. Very few studies involving PPCP mixtures have been conducted; however, the need for these types of studies is warranted as fish are most likely exposed to mixtures of PPCPs in the wild. In addition, laboratory and field assessments of wastewater treatment plant (WWTP) effluents, a major source of PPCPs, are reviewed. Much of the data provided from these assessments are variable and do not generally demonstrate negative impacts on reproduction, or the studies are unable to directly associate observed effects with WWTP effluents. Finally, future research considerations are outlined to provide an avenue into understanding how wild populations of fish are affected by PPCPs. These considerations are aimed at determining the adaptation potential of fish exposed to mixtures of PPCPs over multiple generations. As global use of PPCPs continually rises, the need to discern the effects of chronic exposure to PPCPs is greatly increased.

  2. [Fluorosis of coal burning affects the male reproductive system].

    PubMed

    Li, Jun-Feng; Feng, Jin; Xiao, Yue-Hai; Sun, Fa

    2014-01-01

    Fluorosis of coal burning is a new type of endemic fluorosis in China, which affects the male reproductive system. Furthermore, the content of fluoride in the semen, sperm mortality, sperm concentration and the incidence of infertility are higher in severe fluorosis areas than in mild- and non-fluorosis areas, so are the levels of serum follicle-stimulating hormone and luteinizing hormone. However, the levels of inhibin B, serum testosterone and estradiol show different degrees of reduction in severe fluorosis areas. Accordingly, fluorosis of coal burning, just like other endemic fluorosis, may affect the structure of male reproductive organs, the generation of sperm and reproductive endocrinology, resulting in the decline of men's reproductive ability.

  3. Caste ratios affect the reproductive output of social trematode colonies.

    PubMed

    Kamiya, T; Poulin, R

    2013-03-01

    Intraspecific phenotypic diversification in social organisms often leads to formation of physical castes which are morphologically specialized for particular tasks within the colony. The optimal caste allocation theory argues that specialized morphological castes are efficient at specific tasks, and hence different caste ratios should affect the ergonomic efficiency, hence reproductive output of the colony. However, the reproductive output of different caste ratios has been documented in few species of insects with equivocal support for the theory. This study investigated whether the ratios of nonreproductive and reproductive morphs affect the reproductive output of a recently discovered social trematode, Philophthalmus sp., in which the nonreproductive members are hypothesized to be defensive specialists. A census of natural infections and a manipulative in vitro experiment demonstrated a positive association between the reproductive output of trematode colonies and the ratio of nonreproductive to reproductive morphs in the presence of an intra-host trematode competitor, Maritrema novaezealandensis. On the contrary, without the competitor, reproductive output was negatively associated with the proportion of nonreproductive castes in colonies. Our findings demonstrate for the first time a clear fitness benefit associated with the nonreproductive castes in the presence of a competitor while illustrating the cost of maintaining such morphs in noncompetitive situations. Although the proximate mechanisms controlling caste ratio remain unclear in this trematode system, this study supports the prediction that the fitness of colonies is influenced by the composition of specialized functional morphs in social organisms, suggesting a potential for adaptive shifts of caste ratios over evolutionary time.

  4. Effluent monitoring at a bleached kraft mill: directions for best management practices for eliminating effects on fish reproduction.

    PubMed

    Martel, Pierre H; Kovacs, Tibor G; O'connor, Brian I; Semeniuk, Sharon; Hewitt, L Mark; Maclatchy, Deborah L; McMaster, Mark E; Parrott, Joanne L; van den Heuvel, Michael R; Van Der Kraak, Glen J

    2011-01-01

    A long-term monitoring study was conducted on effluents from a bleached kraft pulp and paper mill located in Eastern Canada. The study was designed to gain insights into temporal effluent variability with respect to fish reproduction as it related to production upsets, mill restarts and conditions affecting biological treatment performance. Final effluent quality was monitored between February 2007 and May 2009 using biochemical and chemical oxygen demand, total suspended solids, resin and fatty acids, a gas chromatographic profiling index, and the presence of methyl substituted 2-cyclopentenones. Selected effluent samples were evaluated for effects on fish reproduction (egg production) using a shortened version of the adult fathead minnow reproductive test. The events relating to negative effects on fish reproduction were upsets of the pulping liquor recovery system resulting in black liquor losses, operational upsets of the hardwood line resulting in the loss of oxygen delignification filtrates, and conditions that reduced the performance of biological treatment (e.g., mill shutdown and low ambient temperatures). The reductions in egg production observed in fathead minnow were associated with biochemical oxygen demand values > 20 mg/L, GC profiling indices > 1.2 and the presence of methyl-substituted 2-cyclopentenones at concentrations > 100 μg/L. This study demonstrated the importance of both in-plant measures for controlling the loss of organics as well as the optimum operation of biological effluent treatment for eliminating effluent-related effects on fish reproduction (egg production) in the laboratory.

  5. The SSRI fluoxetine exhibits mild effects on the reproductive axis in the cichlid fish Cichlasoma dimerus (Teleostei, Cichliformes).

    PubMed

    Dorelle, Luciana S; Da Cuña, Rodrigo H; Rey Vázquez, Graciela; Höcht, Christian; Shimizu, Akio; Genovese, Griselda; Lo Nostro, Fabiana L

    2017-03-01

    Among the wide variety of pharmaceuticals released into the environment, Fluoxetine (FLX), a selective serotonin reuptake inhibitor, is one of the most prescribed for the treatment of major depression. It inhibits serotonin (5-HT) reuptake at the presinaptic membrane, increasing serotonergic activity. In vertebrates, including fish, the serotonergic system is closely related to the Hypothalamic Pituitary Gonadal (HPG) axis which regulates reproduction. As FLX can act as an endocrine disrupting compound (EDC) by affecting several reproductive parameters in fish, the aim of this study was to provide an integral assessment of the potential effect of FLX on the reproductive axis of the Neotropical freshwater fish Cichlasoma dimerus. Adult fish were intraperitoneally injected with 2 μg g(-1) FLX or saline every third day for 15 days. No significant differences were found on serotonergic turnover (5-HIAA/5-HT ratio). Pituitary βLH content in FLX injected females was significantly higher than control females; no significant differences were seen for βFSH content. Sex steroids remained unaltered, both in males and females fish, after FLX treatment. No plasma vitellogenin was induced in treated males. Some alterations were seen in testes of FLX injected males, such as the presence of foam cells and an acidophilic PAS positive, Alcian-Blue negative secretion in the lobular lumen. Although there is no clear consensus about the effect of this drug on reproductive physiology, these results indicate that FLX is acting as a mild EDC in adults of C. dimerus.

  6. Paternal inheritance of growth in fish pursuing alternative reproductive tactics.

    PubMed

    Wirtz-Ocaňa, Sabine; Schütz, Dolores; Pachler, Gudrun; Taborsky, Michael

    2013-06-01

    In species with indeterminate growth, age-related size variation of reproductive competitors within each sex is often high. This selects for divergence in reproductive tactics of same-sex competitors, particularly in males. Where alternative tactics are fixed for life, the causality of tactic choice is often unclear. In the African cichlid Lamprologus callipterus, large nest males collect and present empty snail shells to females that use these shells for egg deposition and brood care. Small dwarf males attempt to fertilize eggs by entering shells in which females are spawning. The bourgeois nest males exceed parasitic dwarf males in size by nearly two orders of magnitude, which is likely to result from greatly diverging growth patterns. Here, we ask whether growth patterns are heritable in this species, or whether and to which extent they are determined by environmental factors. Standardized breeding experiments using unrelated offspring and maternal half-sibs revealed highly divergent growth patterns of male young sired by nest or dwarf males, whereas the growth of female offspring of both male types did not differ. As expected, food had a significant modifying effect on growth, but neither the quantity of breeding substrate in the environment nor ambient temperature affected growth. None of the environmental factors tested influenced the choice of male life histories. We conclude that in L. callipterus growth rates of bourgeois and parasitic males are paternally inherited, and that male and female growth is phenotypically plastic to only a small degree.

  7. Paternal inheritance of growth in fish pursuing alternative reproductive tactics

    PubMed Central

    Wirtz-Ocaňa, Sabine; Schütz, Dolores; Pachler, Gudrun; Taborsky, Michael

    2013-01-01

    In species with indeterminate growth, age-related size variation of reproductive competitors within each sex is often high. This selects for divergence in reproductive tactics of same-sex competitors, particularly in males. Where alternative tactics are fixed for life, the causality of tactic choice is often unclear. In the African cichlid Lamprologus callipterus, large nest males collect and present empty snail shells to females that use these shells for egg deposition and brood care. Small dwarf males attempt to fertilize eggs by entering shells in which females are spawning. The bourgeois nest males exceed parasitic dwarf males in size by nearly two orders of magnitude, which is likely to result from greatly diverging growth patterns. Here, we ask whether growth patterns are heritable in this species, or whether and to which extent they are determined by environmental factors. Standardized breeding experiments using unrelated offspring and maternal half-sibs revealed highly divergent growth patterns of male young sired by nest or dwarf males, whereas the growth of female offspring of both male types did not differ. As expected, food had a significant modifying effect on growth, but neither the quantity of breeding substrate in the environment nor ambient temperature affected growth. None of the environmental factors tested influenced the choice of male life histories. We conclude that in L. callipterus growth rates of bourgeois and parasitic males are paternally inherited, and that male and female growth is phenotypically plastic to only a small degree. PMID:23789072

  8. Reproductive adverse outcome pathways for chemical inhibitors of steroid synthesis in fish

    EPA Science Inventory

    A key physiological process controlling reproductive success of oviparous vertebrates (fish, amphibian, reptiles, birds) involves production of the egg yolk protein precursor vitellogenin (VTG). VTG production is an estrogen receptor (ER)-mediated process that, in females, is con...

  9. Manipulations of the reproductive system of fishes by means of exogenous chemicals

    USGS Publications Warehouse

    Patino, R.

    1997-01-01

    Environmental control of reproductive activity of captive fish is feasible (or potentially feasible) but, with few exceptions, is currently impractical for most species. Therefore, chemical methods of manipulating reproductive activity continue to be widely used in fish production operations worldwide. However, the control of fish reproduction in captivity cannot be exercised without regard to adequate environmental conditions, which can differ markedly for different species. This review provides a synopsis of relevant aspects of fish reproductive physiology and addresses current and promising future chemical methods of sex control, gonadal recrudescence, and spawning. Most research on the control of reproduction in fishes has focused on female physiology because ovarian development and maturation are easily disturbed by environmental stressors. Control of sex ratios by steroid treatment has become a well-established technique for several fish species, but the technique continues to be problematic in some cases. Final gonadal growth and spawning usually can be achieved by implant treatment with gonadotropin-releasing hormone analogs (GnRHa), which in some species have to be applied in combination with dopamine antagonists to enhance responsiveness to GnRHa. However, efforts to accelerate gonadal recrudescence and maturational competence by chemical means have yielded mixed results, reflecting a relative lack of understanding of the basic physiological and biochemic mechanisms controlling these processes. The potential benefits of using reproductive pheromone, to manipulate gonadal development and spawning has been demonstrated in a few species, but further research is needed to determine whether this technique is applicable to fish culture. Because a reliable supply of young fish is critical for the expansion and diversification of fish culture operations, the use of chemicals in combination with adequate environmental conditions to contain gametogenesis and

  10. Reproductive acclimation to increased water temperature in a tropical reef fish.

    PubMed

    Donelson, Jennifer M; McCormick, Mark I; Booth, David J; Munday, Philip L

    2014-01-01

    Understanding the capacity of organisms to cope with projected global warming through acclimation and adaptation is critical to predicting their likely future persistence. While recent research has shown that developmental acclimation of metabolic attributes to ocean warming is possible, our understanding of the plasticity of key fitness-associated traits, such as reproductive performance, is lacking. We show that while the reproductive ability of a tropical reef fish is highly sensitive to increases in water temperature, reproductive capacity at +1.5°C above present-day was improved to match fish maintained at present-day temperatures when fish complete their development at the higher temperature. However, reproductive acclimation was not observed in fish reared at +3.0°C warmer than present-day, suggesting limitations to the acclimation possible within one generation. Surprisingly, the improvements seen in reproduction were not predicted by the oxygen- and capacity-limited thermal tolerance hypothesis. Specifically, pairs reared at +1.5°C, which showed the greatest capacity for reproductive acclimation, exhibited no acclimation of metabolic attributes. Conversely, pairs reared at +3.0°C, which exhibited acclimation in resting metabolic rate, demonstrated little capacity for reproductive acclimation. Our study suggests that understanding the acclimation capacity of reproductive performance will be critically important to predicting the impacts of climate change on biological systems.

  11. Body reserves mediate trade-offs between life-history traits: new insights from small pelagic fish reproduction

    PubMed Central

    Lloret, Josep; Muñoz, Marta; Fauvel, Christian; Van Beveren, Elisabeth; Marques, Virginie; Fromentin, Jean-Marc; Ménard, Frédéric; Saraux, Claire

    2016-01-01

    Limited resources in the environment prevent individuals from simultaneously maximizing all life-history traits, resulting in trade-offs. In particular, the cost of reproduction is well known to negatively affect energy investment in growth and maintenance. Here, we investigated these trade-offs during contrasting periods of high versus low fish size and body condition (before/after 2008) in the Gulf of Lions. Female reproductive allocation and performance in anchovy (Engraulis encrasicolus) and sardine (Sardina pilchardus) were examined based on morphometric historical data from the 1970s and from 2003 to 2015. Additionally, potential maternal effects on egg quantity and quality were examined in 2014/2015. After 2008, the gonadosomatic index increased for sardine and remained steady for anchovy, while a strong decline in mean length at first maturity indicated earlier maturation for both species. Regarding maternal effects, for both species egg quantity was positively linked to fish size but not to fish lipid reserves, while the egg quality was positively related to lipid reserves. Atresia prevalence and intensity were rather low regardless of fish condition and size. Finally, estimations of total annual numbers of eggs spawned indicated a sharp decrease for sardine since 2008 but a slight increase for anchovy during the last 5 years. This study revealed a biased allocation towards reproduction in small pelagic fish when confronted with a really low body condition. This highlights that fish can maintain high reproductive investment potentially at the cost of other traits which might explain the present disappearance of old and large individuals in the Gulf of Lions. PMID:27853538

  12. Body reserves mediate trade-offs between life-history traits: new insights from small pelagic fish reproduction.

    PubMed

    Brosset, Pablo; Lloret, Josep; Muñoz, Marta; Fauvel, Christian; Van Beveren, Elisabeth; Marques, Virginie; Fromentin, Jean-Marc; Ménard, Frédéric; Saraux, Claire

    2016-10-01

    Limited resources in the environment prevent individuals from simultaneously maximizing all life-history traits, resulting in trade-offs. In particular, the cost of reproduction is well known to negatively affect energy investment in growth and maintenance. Here, we investigated these trade-offs during contrasting periods of high versus low fish size and body condition (before/after 2008) in the Gulf of Lions. Female reproductive allocation and performance in anchovy (Engraulis encrasicolus) and sardine (Sardina pilchardus) were examined based on morphometric historical data from the 1970s and from 2003 to 2015. Additionally, potential maternal effects on egg quantity and quality were examined in 2014/2015. After 2008, the gonadosomatic index increased for sardine and remained steady for anchovy, while a strong decline in mean length at first maturity indicated earlier maturation for both species. Regarding maternal effects, for both species egg quantity was positively linked to fish size but not to fish lipid reserves, while the egg quality was positively related to lipid reserves. Atresia prevalence and intensity were rather low regardless of fish condition and size. Finally, estimations of total annual numbers of eggs spawned indicated a sharp decrease for sardine since 2008 but a slight increase for anchovy during the last 5 years. This study revealed a biased allocation towards reproduction in small pelagic fish when confronted with a really low body condition. This highlights that fish can maintain high reproductive investment potentially at the cost of other traits which might explain the present disappearance of old and large individuals in the Gulf of Lions.

  13. Environmental Factors Affecting Large-Bodied Coral Reef Fish Assemblages in the Mariana Archipelago

    PubMed Central

    Richards, Benjamin L.; Williams, Ivor D.; Vetter, Oliver J.; Williams, Gareth J.

    2012-01-01

    Large-bodied reef fishes represent an economically and ecologically important segment of the coral reef fish assemblage. Many of these individuals supply the bulk of the reproductive output for their population and have a disproportionate effect on their environment (e.g. as apex predators or bioeroding herbivores). Large-bodied reef fishes also tend to be at greatest risk of overfishing, and their loss can result in a myriad of either cascading (direct) or indirect trophic and other effects. While many studies have investigated habitat characteristics affecting populations of small-bodied reef fishes, few have explored the relationship between large-bodied species and their environment. Here, we describe the distribution of the large-bodied reef fishes in the Mariana Archipelago with an emphasis on the environmental factors associated with their distribution. Of the factors considered in this study, a negative association with human population density showed the highest relative influence on the distribution of large-bodied reef fishes; however, depth, water temperature, and distance to deep water also were important. These findings provide new information on the ecology of large-bodied reef fishes can inform discussions concerning essential fish habitat and ecosystem-based management for these species and highlight important knowledge gaps worthy of additional research. PMID:22384014

  14. Impairments in aromatase expression, reproductive behavior, and sperm quality of male fish exposed to 17β-estradiol.

    PubMed

    Guyón, Noelia F; Roggio, María A; Amé, María V; Hued, Andrea C; Valdés, María E; Giojalas, Laura C; Wunderlin, Daniel A; Bistoni, María A

    2012-05-01

    Growing evidence shows that environmental estrogen can reach levels that are high enough to exert adverse reproductive effects on wild fish populations. The authors report different parameters of male reproductive behavior, brain, and gonadal aromatase expression, as well as sperm quality in an internally fertilizing fish species (Jenynsia multidentata, Jenyns) exposed to environmentally relevant concentrations of 17β-estradiol (E(2) ). Adult males were exposed to 0, 50, 100, and 250 ng/L E(2) over 28 d. The authors' findings demonstrate that E(2) exposure resulted in a very clear increase in brain aromatase transcript abundance at all assayed concentrations compared with control; however, no effects on gonadal aromatase expression were observed. Behavioral measures revealed increased sexual activity at 50 ng/L but not 100 or 250 ng/L E(2) . In contrast to the molecular and behavioral responses, the condition factor, gonadosomatic index, and sperm quality were unaltered by E(2) exposure. The results from the present work suggest that E(2) affects some aspects of the reproductive biology of J. multidentata. These modifications in the reproductive biology caused by exposure to E(2) could potentially lead to long-term effects at population levels that may not always be immediately evident. To the best of the authors' knowledge, this is the first report on the combined effect of E(2) on aromatase expression, sexual behavior, and sperm parameters in fish.

  15. A geographical genetics framework for inferring homing reproductive behavior in fishes.

    PubMed

    de Campos Telles, Mariana Pires; Collevatti, Rosane Garcia; da Costa, Marcio Candido; Barthem, Ronaldo Borges; da Silva, Nelson Jorge; Neto, Advaldo Carlos Souza; Diniz-Filho, José Alexandre Felizola

    2011-02-01

    One of the most intriguing patterns of migration and gene flow that affects genetic structure is the reproductive homing behavior of fishes, wherein the adults return to the areas in which they were spawned. Here we reviewed the literature on homing behavior in fish and propose an analytical framework for testing hypotheses regarding this behavior and its effects on the genetic structure of fish in an explicit geographical context, using a geographical genetics toolbox. Although disentangling the many potential causes underlying genetic population structure and unambiguously demonstrating that the homing behavior causes these genetic patterns is difficult, our framework allows the successive testing of homing behavior with increasing levels of complexity based on the following: (1) establishment of population structures among waterheads; (2) patterns of genetic variability throughout the adult migratory pool; (3) analyses of the non-migratory adult pool; and (4) comparisons among successive generations. We expect that the framework presented here will help delineating the appropriate uses of different sampling designs to make inferences regarding homing behavior and illustrate the limits imposed by the interpretation of different types of genetic data. More importantly, we hope this framework enables researchers to understand how a particular dataset can be utilized in a broader context as an ongoing part of a larger research program and thus guide future research by developing better and more integrated sampling designs.

  16. Temporal Uncoupling between Energy Acquisition and Allocation to Reproduction in a Herbivorous-Detritivorous Fish.

    PubMed

    Villamarín, Francisco; Magnusson, William E; Jardine, Timothy D; Valdez, Dominic; Woods, Ryan; Bunn, Stuart E

    2016-01-01

    Although considerable knowledge has been gathered regarding the role of fish in cycling and translocation of nutrients across ecosystem boundaries, little information is available on how the energy obtained from different ecosystems is temporally allocated in fish bodies. Although in theory, limitations on energy budgets promote the existence of a trade-off between energy allocated to reproduction and somatic growth, this trade-off has rarely been found under natural conditions. Combining information on RNA:DNA ratios and carbon and nitrogen stable-isotope analyses we were able to achieve novel insights into the reproductive allocation of diamond mullet (Liza alata), a catadromous, widely distributed herbivorous-detritivorous fish. Although diamond mullet were in better condition during the wet season, most reproductive allocation occurred during the dry season when resources are limited and fish have poorer body condition. We found a strong trade-off between reproductive and somatic investment. Values of δ13C from reproductive and somatic tissues were correlated, probably because δ13C in food resources between dry and wet seasons do not differ markedly. On the other hand, data for δ15N showed that gonads are more correlated to muscle, a slow turnover tissue, suggesting long term synthesis of reproductive tissues. In combination, these lines of evidence suggest that L. alata is a capital breeder which shows temporal uncoupling of resource ingestion, energy storage and later allocation to reproduction.

  17. Temporal Uncoupling between Energy Acquisition and Allocation to Reproduction in a Herbivorous-Detritivorous Fish

    PubMed Central

    Villamarín, Francisco; Magnusson, William E.; Jardine, Timothy D.; Valdez, Dominic; Woods, Ryan; Bunn, Stuart E.

    2016-01-01

    Although considerable knowledge has been gathered regarding the role of fish in cycling and translocation of nutrients across ecosystem boundaries, little information is available on how the energy obtained from different ecosystems is temporally allocated in fish bodies. Although in theory, limitations on energy budgets promote the existence of a trade-off between energy allocated to reproduction and somatic growth, this trade-off has rarely been found under natural conditions. Combining information on RNA:DNA ratios and carbon and nitrogen stable-isotope analyses we were able to achieve novel insights into the reproductive allocation of diamond mullet (Liza alata), a catadromous, widely distributed herbivorous-detritivorous fish. Although diamond mullet were in better condition during the wet season, most reproductive allocation occurred during the dry season when resources are limited and fish have poorer body condition. We found a strong trade-off between reproductive and somatic investment. Values of δ13C from reproductive and somatic tissues were correlated, probably because δ13C in food resources between dry and wet seasons do not differ markedly. On the other hand, data for δ15N showed that gonads are more correlated to muscle, a slow turnover tissue, suggesting long term synthesis of reproductive tissues. In combination, these lines of evidence suggest that L. alata is a capital breeder which shows temporal uncoupling of resource ingestion, energy storage and later allocation to reproduction. PMID:26938216

  18. Experimental examination of interpopulation variation in reproductive timing of a fish.

    PubMed

    Yamahira, K

    2001-08-01

    Many marine organisms have a specific reproductive timing, but its adaptive nature has not been directly tested because of the difficulty of manipulating reproductive timing in the field. Egg survival in relation to the timing of egg release in the puffer Takifugu niphobles, an intertidal spawner, was assessed by experimentally transplanting eggs to several tidal zones, and the observed pattern of variation in spawning time across environments (a pebble vs. a sandy beach) was examined to see if it was consistent with the presumed selection regime. The vertical distribution of eggs and the observation of spawning zones showed that substrate characteristics affected the fate of released eggs: at the pebble beach eggs were stranded in the high intertidal zone, while they were washed out toward the lower zone at the sandy beach. The egg-transplant experiment showed that egg survival was lower in the high zone than in the middle and low zones at both the pebble and sandy beaches, indicating that individual fishes should spawn earlier relative to the tidal cycle. However, the selection pressure for thefish to spawn earlier was more intense at the pebble beach than at the sandy beach, which was attributed to the difference between the beaches in the degree to which eggs were transported seaward. At the pebble beach (1) the timing of spawning was more strictly synchronized with the tidal cycle, (2) a day's spawning started, peaked, and ended earlier relative to the tidal cycle, and (3) a day's spawning was concentrated in a shorter time, than at the sandy beach. These temporal patterns of spawning are allexpected from the presumed selection regime across the beaches, suggesting that there is an evolutionary response of the trait to this selective force. This study explains interpopulation variation in reproductive timing of a marine fish by combining experimental manipulations of the reproductive timing with classic comparative methods. This experimental approach performed

  19. Interpreting the von Bertalanffy model of somatic growth in fishes: the cost of reproduction.

    PubMed Central

    Lester, N. P.; Shuter, B. J.; Abrams, P. A.

    2004-01-01

    We develop a model for somatic growth in fishes that explicitly allows for the energy demand imposed by reproduction. We show that the von Bertalanffy (VB) equation provides a good description of somatic growth after maturity, but not before. We show that the parameters of the VB equation are simple functions of age at maturity and reproductive investment. We use this model to show how the energy demands for both growth and reproduction trade off to determine optimal life-history traits. Assuming that both age at maturity and reproductive investment adapt to variations in adult mortality to maximize lifetime offspring production, our model predicts that: (i) the optimal age of maturity is inversely related to adult mortality rate; (ii) the optimal reproductive effort is approximately equal to adult mortality rate. These predictions are consistent with observed variations in the life-history traits of a large sample of iteroparous freshwater fishes. PMID:15306310

  20. The potential impacts of migratory difficulty, including warmer waters and altered flow conditions, on the reproductive success of salmonid fishes.

    PubMed

    Fenkes, Miriam; Shiels, Holly A; Fitzpatrick, John L; Nudds, Robert L

    2016-03-01

    Climate change and urbanisation of watercourses affect water temperatures and current flow velocities in river systems on a global scale. This represents a particularly critical issue for migratory fish species with complex life histories that use rivers to reproduce. Salmonids are migratory keystone species that provide substantial economical value to ecosystems and human societies. Consequently, a comprehensive understanding of the effects of environmental stressors on their reproductive success is critical in order to ensure their continued abundance during future climatic change. Salmonids are capital breeders, relying entirely on endogenous energy stores to fuel return migration to their natal spawning sites and reproduction upon arrival. Metabolic rates and cost of transport en-route increase with temperature and at extreme temperatures, swimming is increasingly fuelled anaerobically, resulting in an oxygen debt and reduced capacity to recover from exhaustive exercise. Thermally challenged salmonids also produce less viable gametes, which themselves are affected by water temperature after release. Passage through hydrological barriers and temperature changes both affect energy expenditure. As a result, important energetic tradeoffs emerge between extra energy used during migration and that available for other facets of the reproductive cycle, such as reproductive competition and gamete production. However, studies identifying these tradeoffs are extremely sparse. This review focuses on the specific locomotor responses of salmonids to thermal and hydrological challenges, identifying gaps in our knowledge and highlighting the potential implications for key aspects of their reproduction.

  1. The potential impacts of migratory difficulty, including warmer waters and altered flow conditions, on the reproductive success of salmonid fishes

    PubMed Central

    Fenkes, Miriam; Shiels, Holly A.; Fitzpatrick, John L.; Nudds, Robert L.

    2016-01-01

    Climate change and urbanisation of watercourses affect water temperatures and current flow velocities in river systems on a global scale. This represents a particularly critical issue for migratory fish species with complex life histories that use rivers to reproduce. Salmonids are migratory keystone species that provide substantial economical value to ecosystems and human societies. Consequently, a comprehensive understanding of the effects of environmental stressors on their reproductive success is critical in order to ensure their continued abundance during future climatic change. Salmonids are capital breeders, relying entirely on endogenous energy stores to fuel return migration to their natal spawning sites and reproduction upon arrival. Metabolic rates and cost of transport en-route increase with temperature and at extreme temperatures, swimming is increasingly fuelled anaerobically, resulting in an oxygen debt and reduced capacity to recover from exhaustive exercise. Thermally challenged salmonids also produce less viable gametes, which themselves are affected by water temperature after release. Passage through hydrological barriers and temperature changes both affect energy expenditure. As a result, important energetic tradeoffs emerge between extra energy used during migration and that available for other facets of the reproductive cycle, such as reproductive competition and gamete production. However, studies identifying these tradeoffs are extremely sparse. This review focuses on the specific locomotor responses of salmonids to thermal and hydrological challenges, identifying gaps in our knowledge and highlighting the potential implications for key aspects of their reproduction. PMID:26603555

  2. Age, sex and reproductive status affect boldness in dogs.

    PubMed

    Starling, Melissa J; Branson, Nicholas; Thomson, Peter C; McGreevy, Paul D

    2013-09-01

    Boldness in dogs is believed to be one end of the shy-bold axis, representing a super-trait. Several personality traits fall under the influence of this super-trait. Previous studies have found that boldness is affected by breed and breed groups, influences performance in sporting dogs, and is affected in some cases by the sex of the dogs. This study investigated the effects of dog age, sex and reproductive status on boldness in dogs by way of a dog personality survey circulated amongst Australian dog owners. Age had a significant effect on boldness (F=4.476; DF=16,758; P<0.001), with boldness decreasing with age in years. Males were bolder than females (F=19.219; DF=1,758; P<0.001) and entire dogs were bolder than neutered dogs (F=4.330; DF=1,758; P<0.038). The study indicates how behaviour may change in adult dogs as they age and adds to the literature on how sex and reproductive status may affect personality in dogs.

  3. Predation risk affects reproductive physiology and demography of elk.

    PubMed

    Creel, Scott; Christianson, David; Liley, Stewart; Winnie, John A

    2007-02-16

    Elk (Cervus elaphus) in the Greater Yellowstone Ecosystem alter patterns of aggregation, habitat selection, vigilance, and foraging in the presence of wolves (Canis lupus). Antipredator behaviors like these can reduce predation risk but are also likely to carry costs. Data from five elk populations studied for 16 site years showed that progesterone concentrations (from 1489 fecal samples) declined with the ratio of elk to wolves. In turn, progesterone concentrations were a good predictor of calf recruitment in the subsequent year. Together, these data suggest that wolves indirectly affect the reproductive physiology and the demography of elk through the costs of antipredator behavior.

  4. Production of reproductively sterile fish: A mini-review of germ cell elimination technologies.

    PubMed

    Wong, Ten-Tsao; Zohar, Yonathan

    2015-09-15

    As seafood consumption shifts from fisheries harvests to artificially propagated aquatic species, the increase of aquaculture activities poses a biological threat to our environment. Selectively bred, non-native and (eventually) genetically engineered farmed fish may escape from aquaculture operations, propagate and/or interbreed with wild stocks and subsequently alter the genetic makeup of populations in the environment. Thus, an effective strategy for bio-containment of farmed fish is critically needed. Farming reproductively sterile fish is the most environmentally sustainable approach to ensure complete bio-containment in large-scale aquaculture operations. Chromosome set manipulations to produce sterile fish, including polyploidy and hybridization, are currently the most common practices in the aquaculture industry. However, they do not always result in 100% sterility of the treated fish. Moreover, triploid fish typically do not perform as well as the non-manipulated diploids under commercial culture conditions. In the last half decade, several genetic engineering methods have been developed to produce sterile fish. In this review, we will address the latest technologies that use transgenic approaches to eliminate germ cells, resulting in the production of sterile fish. These latest advances also led us to the development of egg/embryo immersion methodologies to deliver and screen compounds that can be used to eliminate primordial germ cells and produce sterile fish. This emerging non-transgenic strategy for the production of reproductively sterile fish in aquaculture will also be discussed.

  5. On the reproductive success of early-generation hatchery fish in the wild

    PubMed Central

    Christie, Mark R; Ford, Michael J; Blouin, Michael S

    2014-01-01

    Large numbers of hatchery salmon spawn in wild populations each year. Hatchery fish with multiple generations of hatchery ancestry often have heritably lower reproductive success than wild fish and may reduce the fitness of an entire population. Whether this reduced fitness also occurs for hatchery fish created with local- and predominantly wild-origin parents remains controversial. Here, we review recent studies on the reproductive success of such ‘early-generation’ hatchery fish that spawn in the wild. Combining 51 estimates from six studies on four salmon species, we found that (i) early-generation hatchery fish averaged only half the reproductive success of their wild-origin counterparts when spawning in the wild, (ii) the reduction in reproductive success was more severe for males than for females, and (iii) all species showed reduced fitness due to hatchery rearing. We review commonalities among studies that point to possible mechanisms (e.g., environmental versus genetic effects). Furthermore, we illustrate that sample sizes typical of these studies result in low statistical power to detect fitness differences unless the differences are substantial. This review demonstrates that reduced fitness of early-generation hatchery fish may be a general phenomenon. Future research should focus on determining the causes of those fitness reductions and whether they lead to long-term reductions in the fitness of wild populations. PMID:25469167

  6. AOP description: Aromatase inhibition leading to reproductive dysfunction (in fish)

    EPA Science Inventory

    This adverse outcome pathway details the linkage between inhibition of gonadal aromatase activity in females and the adverse effect of reduced cumulative fecundity in repeat-spawning fish species. Cumulative fecundity is the most apical endpoint considered in the OECD 229 Fish Sh...

  7. AOP description: ER antagonism leading to reproductive dysfunction (in fish)

    EPA Science Inventory

    This adverse outcome pathway details the linkage between antagonism of estrogen receptor in females and the adverse effect of reduced cumulative fecundity in repeat-spawning fish species. Cumulative fecundity is the most apical endpoint considered in the OECD 229 Fish Short Term ...

  8. An overview of estrogen-associated endocrine disruption in fishes: evidence of effects on reproductive and immune physiology

    USGS Publications Warehouse

    Iwanowicz, L.R.; Blazer, V.S.

    2011-01-01

    Simply and perhaps intuitively defined, endocrine disruption is the abnormal modulation of normal hormonal physiology by exogenous chemicals. In fish, endocrine disruption of the reproductive system has been observed worldwide in numerous species and is known to affect both males and females. Observations of biologically relevant endocrine disruption most commonly occurs near waste water treatment plant outfalls, pulp and paper mills, and areas of high organic loading sometimes associated with agricultural practices. Estrogenic endocrine disrupting chemicals (EEDCs) have received an overwhelmingly disproportionate amount of scientific attention compared to other EDCs in recent years. In male fishes, exposure to EEDCs can lead to the induction of testicular oocytes (intersex), measurable plasma vitellogenin protein, altered sex steroid profiles, abnormal spawning behavior, skewed population sex ratios, and lessened reproductive success. Interestingly, contemporary research purports that EDCs modulate aspects of non-reproductive physiology including immune function. Here we present an overview of endocrine disruption in fishes associated with estrogenic compounds, implications of this phenomenon, and examples of EDC related research findings by our group in the Potomac River Watershed, USA.

  9. Probabilistic assessment of risks of diethylhexyl phthalate (DEHP) in surface waters of China on reproduction of fish.

    PubMed

    Liu, Na; Wang, Yeyao; Yang, Qi; Lv, Yibing; Jin, Xiaowei; Giesy, John P; Johnson, Andrew C

    2016-06-01

    Diethylhexyl phthalate (DEHP) is considered to be an endocrine disruptor, which unlike other chemicals that have either non-specific (e.g., narcotics) or more generalized reactive modes of action, affect the Hypothalamic-pituitary-gonadal (HPG) axis and tend to have specific interactions with particular molecular targets within biochemical pathways. Responding to this challenge, a novel method for deriving predicted no-effect concentration (PNEC) and probabilistic ecological risk assessment (PERAs) for DEHP based on long-term exposure to potentially sensitive species with appropriate apical endpoints was development for protection of Chinese surface waters. PNECs based on potencies to cause lesions in reproductive tissues of fishes, which ranged from 0.04 to 0.20 μg DEHP L(-1), were significantly less than those derived based on other endpoints or other taxa, such as invertebrates. An assessment of risks posed by DEHP to aquatic organisms in surface waters of China showed that 88.17% and 78.85% of surface waters in China were predicted to pose risks to reproductive fitness of fishes with thresholds of protection for aquatic organisms based on 5% (HC5) and 10% (HC10), respectively. Assessment of risks of effects based on effects mediated by the HPG-axis should consider effects on chronic, non-lethal endpoints for specific taxa, especially for reproductive fitness of fishes.

  10. Female germ cell renewal during the annual reproductive cycle in Ostariophysians fish.

    PubMed

    Wildner, Daniel Dantas; Grier, Harry; Quagio-Grassiotto, Irani

    2013-03-01

    The objective was to characterize female germ cell renewal during the annual reproductive cycle in two species of ostariophysian fish with distinct reproductive strategies: a siluriform, Pimelodus maculatus, in which oocyte development is group synchronous and the annual reproductive period is short; and a characiform, Serrasalmus maculatus, with asynchronous oocyte development and a prolonged reproductive period. These reproductive strategies result in fish determinate and indeterminate fecundity, respectively. Annual reproductive phases were determined by biometric and histologic analysis of gonads and interpreted according to new proposals for phase classification and stages of oocyte development (with special attention to germinal epithelium activity). Histologically, there were two types of oogonia in the germinal epithelium: single oogonia and those in mitotic proliferation. Oogonial proliferation and their entry into meiosis resulted in formation of cell nests (clusters of cells in the ovarian lamellae). Morphometric analysis was used to estimate germ cell renewal. Based on numbers of single oogonia in the lamellar epithelium, and nests with proliferating oogonia or early prophase oocytes throughout the annual reproductive cycle, oogonial proliferation and entrance into meiosis were more intense during the regenerating phase and developing phase, but decreased sharply (P < 0.05) during the spawning-capable phase. Oogonial proliferation gradually recovered during the regressing phase. We concluded that, independent of species or features of the reproductive cycle, germ cell renewal occurred during the regenerating phase, ensuring availability of eggs for the spawning event.

  11. Reproduction of a fish assemblage in the state of São Paulo, southeastern Brazil.

    PubMed

    Gomiero, L M; Braga, F M S

    2007-05-01

    Fish reproductions were studied in two river basins (Corumbataí and Jacaré-Pepira basins) in the State of São Paulo, southeastern Brazil. In the Corumbataí basin, four sites were sampled: Cabeça River, Lapa Stream, Passa-Cinco River, and Corumbataí River; in the Jacaré-Pepira basin, three sites were sampled: Tamanduá Stream, Jacaré-Pepira River, and Agua Branca Stream. A total of 12 bimonthly samples were made. Fish equipment included gill nets, purse seines, sieves, and traps. The main objective of this study was to characterize the fish assemblage regarding their reproductive biology and to compare these reproductive traits between both river basins. Most individuals with gonads in stage C (mature) and in stage D (empty gonads) were captured in the spring and summer. Multiple spawn and parental care were common strategies, which guaranteed offspring survivorship in unstable conditions.

  12. Community structure affects trophic ontogeny in a predatory fish.

    PubMed

    Sánchez-Hernández, Javier; Eloranta, Antti P; Finstad, Anders G; Amundsen, Per-Arne

    2017-01-01

    While most studies have focused on the timing and nature of ontogenetic niche shifts, information is scarce about the effects of community structure on trophic ontogeny of top predators. We investigated how community structure affects ontogenetic niche shifts (i.e., relationships between body length, trophic position, and individual dietary specialization) of a predatory fish, brown trout (Salmo trutta). We used stable isotope and stomach content analyses to test how functional characteristics of lake fish community compositions (competition and prey availability) modulate niche shifts in terms of (i) piscivorous behavior, (ii) trophic position, and (iii) individual dietary specialization. Northern Scandinavian freshwater fish communities were used as a study system, including nine subarctic lakes with contrasting fish community configurations: (i) trout-only systems, (ii) two-species systems (brown trout and Arctic charr [Salvelinus alpinus] coexisting), and (iii) three-species systems (brown trout, Arctic charr, and three-spined sticklebacks [Gasterosteus aculeatus] coexisting). We expected that the presence of profitable small prey (stickleback) and mixed competitor-prey fish species (charr) supports early piscivory and high individual dietary specialization among trout in multispecies communities, whereas minor ontogenetic shifts were expected in trout-only systems. From logistic regression models, the presence of a suitable prey fish species (stickleback) emerged as the principal variable determining the size at ontogenetic niche shifts. Generalized additive mixed models indicated that fish community structure shaped ontogenetic niche shifts in trout, with the strongest positive relationships between body length, trophic position, and individual dietary specialization being observed in three-species communities. Our findings revealed that the presence of a small-sized prey fish species (stickleback) rather than a mixed competitor-prey fish species (charr) was

  13. Is there a reproductive basis to solitary living versus pair-formation in coral reef fishes?

    NASA Astrophysics Data System (ADS)

    Pratchett, Morgan S.; Pradjakusuma, Oki. A.; Jones, Geoffrey P.

    2006-03-01

    Many species of coral reef fishes form pairs. While it is assumed that pairs represent the breeding unit of these species, the reproductive status of paired versus solitary individuals, and changes in status associated with pair-formation have seldom been investigated. In order to assess whether pairing is related to reproduction we examined whether the ontogenetic timing of pair formation coincided with the onset of maturation in four species of fishes: Chaetodon lunulatus and Chaetodon melannotus (family Chaetodontidae), and Valenciennea muralis and Valenciennea strigata (family Gobiidae). 65-78% of all fishes occurred in pairs. In C. lunulatus and V. muralis, pair-formation coincided with maturation, suggesting that these species form pairs for breeding. Further, C. lunulatus and V. muralis exhibited significant positive size-assortative pairing, which is often associated with monogamous mating. In contrast, pair formation in C. melannotus and V. strigata did not coincide with maturation. In both these species many solitary individuals were reproductive, and same sex pairs were common. While reproduction may be the basis for pairing in some species, both solitary and paired individuals are capable of breeding in others. We propose that non-reproductive mechanisms, such as predator vigilance, may explain pair-formation in coral reef fishes with non-monogamous breeding systems.

  14. A review on the effects of PBDEs on thyroid and reproduction systems in fish.

    PubMed

    Yu, Liqin; Han, Zhihua; Liu, Chunsheng

    2015-08-01

    The objective of this review was to summarize and discuss the effects of Polybrominated diphenyl ethers (PBDEs) on thyroid and reproduction systems in fish. We reviewed the evidences and mechanisms for PBDEs-induced thyroid and reproduction disruption, as well as the cross-talk between the two systems in fish. In thyroid disruption, we mainly paid attention to the effects of PBDEs on hypothalamic-pituitary-thyroid (HPT) axis, thyroid hormones (THs) transport and metabolism, thyroid receptors (TRs) and thyroid follicle histology. In reproduction disruption, we focused on the effects of PBDEs on steroid hormone production, expression of genes involved in steroidogenesis, and gonadal development. Despite that there is an interaction between thyroid and reproductive systems in fish, it is still remains unclear that PBDE-induced reproductive impairments are caused by direct effects on hypothalamic-pituitary-gonadal (HPG) functioning or by indirect action through cross-talk between the two systems. Future studies are needed to explore the relationships between reproductive toxicity and thyroid system disruption after PBDEs exposure.

  15. Reproductive and histopathological effects in wild fish inhabiting an effluent-dominated stream, Wascana Creek, SK, Canada.

    PubMed

    Tetreault, Gerald R; Bennett, C James; Cheng, Carl; Servos, Mark R; McMaster, Mark E

    2012-04-01

    During the winter low flow periods, Wascana Creek, Saskatchewan, Canada, can be 100% treated municipal wastewater downstream of the City of Regina's Wastewater Treatment Plant. The objective of this study was to determine if exposure to municipal effluent affects the health and reproductive development of fish in an effluent-dominated stream. Field studies were conducted on post-spawning (August 2006), spawning (June 2007), recrudescent (October 2007) and pre-spawning (May 2008) sentinel fish [Fathead Minnow Pimephales promelas and Brook Stickleback Culaea inconstans] to assess responses in terms of growth (condition factor), reproduction (in vitro sex steroid biosynthetic capacity, and gonadosomatic indices, histology) and survival associated with the effluent outfall. Sentinel species demonstrated varying responses depending on the season of field collections. While Stickleback collected downstream of the sewage discharge were often longer, heavier and had greater condition, Fatheads from the same site were shorter and lighter. Exposed fish of both species exhibited delayed spawning and altered gonadal development depending on the season. Exposed male Fathead Minnows also had significantly lower scores of secondary sexual characteristics (fewer nuptial tubercles, little or no development of the dorsal pad, and the lack of presence of a dorsal fin dot). Histopathology of exposed Fathead Minnows revealed thickening of the gill lamellae and alterations in structure of the kidneys (inflammation of the proximal tubules and Bowman's capsule). It is not known if the effluents are affecting natural reproduction and recruitment into this population or if these impacted populations rely on immigration from upstream reaches to sustain the populations. Climate change and human population growth will further challenge this effluent-dominated stream's ability to assimilate nutrients and contaminants which may further impair the performance of fish in this arid environment.

  16. Temperature is the evil twin: effects of increased temperature and ocean acidification on reproduction in a reef fish.

    PubMed

    Miller, G M; Kroon, F J; Metcalfe, S; Mundayi, P L

    2015-04-01

    Reproduction in many organisms can be disrupted by changes to the physical environment, such as those predicted to occur during climate change. Marine organisms face the dual climate change threats of increasing temperature and ocean acidification, yet no studies have examined the potential interactive effects of these stressors on reproduction in marine fishes. We used a long-term experiment to test the interactive effects of increased temperature and CO2 on the reproductive performance of the anemonefish, Amphiprion melanopus. Adult breeding pairs were kept for 10 months at three temperatures (28.5°C [+0.0°C], 30.0°C [-1.5°C] and 31.5°C [+3.0°C]) cross-factored with three CO2 levels (a current-day control [417 µatm] and moderate [644 µatm] and high [1134 µatm]) treatments consistent with the range of CO2 projections for the year 2100. We recorded each egg clutch produced during the breeding season, the number of eggs laid per clutch, average egg size, fertilization success, survival to hatching, hatchling length, and yolk provisioning. Adult body condition, hepatosomatic index, gonadosomatic index, and plasma 17β-estradiol concentrations were measured at the end of the breeding season to determine the effect of prolonged exposure to increased temperature and elevated. CO2 on adults, and to examine potential physiological mechanisms for changes in reproduction. Temperature had by far the stronger influence on reproduction, with clear declines in reproduction occurring in the +1.5°C treatment and ceasing altogether in the +3.0°C treatment. In contrast, CO2 had a minimal effect on the majority of reproductive traits measured, but caused a decline in offspring quality in combination with elevated temperature. We detected no significant effect of temperature or Co2 on adult body condition or hepatosomatic index. Elevated temperature had a significant negative effect on plasma 17β-estradiol concentrations, suggesting that declines in reproduction with

  17. Current and future assisted reproductive technologies for fish species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Food and Agriculture Organization of the United Nations (FAO) estimates that in 2012 aquaculture production of fish will meet or exceed that of the capture fisheries for the first time. Thus, we have just turned the corner from a predominantly hunting gathering approach to meeting our nutrition...

  18. A systems biology approach to understanding impacts of environmental contaminants on fish reproduction

    EPA Science Inventory

    Over the past decade, our research team at the US EPA Mid-Continent Ecology Division has employed systems biology approaches to examine and understand impacts of environmental contaminants on fish reproduction. Our systems biology approach is one in which iterations of model cons...

  19. EFFECTS OF EXPOSURE TO THREE STEROID ESTROGENS ON REPRODUCTIVE PARAMETERS IN A FISH TAUTOGOLABRUS ADSPERSUS

    EPA Science Inventory

    Estradiol (E2), ethynylestradiol (EE2) and estrone (E4) are steroidal estrogens that are released into the aquatic environment in sewage treatment effluent. To determine whether these estrogens impact reproductive parameters in a model fish species, actively-reproducing cunner (T...

  20. EFFECTS OF EXPOSURE TO ENVIRONMENTAL ESTROGENS ON REPRODUCTIVE PARAMETERS IN A MARINE FISH, TAUTOGOLABRUS ADSPERSUS

    EPA Science Inventory

    Estradiol (E2), ethynylestradiol (EE2) and estrone (E4) are steroidal estrogens that are released into the aquatic environment in sewage treatment effluent. To determine whether these estrogens could impact reproductive parameters in a model fish species, actively spawning male ...

  1. Neural and hormonal mechanisms of reproductive-related arousal in fishes.

    PubMed

    Forlano, Paul M; Bass, Andrew H

    2011-05-01

    The major classes of chemicals and brain pathways involved in sexual arousal in mammals are well studied and are thought to be of an ancient, evolutionarily conserved origin. Here we discuss what is known of these neurochemicals and brain circuits in fishes, the oldest and most species-rich group of vertebrates from which tetrapods arose over 350 million years ago. Highlighted are case studies in vocal species where well-delineated sensory and motor pathways underlying reproductive-related behaviors illustrate the diversity and evolution of brain mechanisms driving sexual motivation between (and within) sexes. Also discussed are evolutionary insights from the neurobiology and reproductive behavior of elasmobranch fishes, the most ancient lineage of jawed vertebrates, which are remarkably similar in their reproductive biology to terrestrial mammals.

  2. Quantum dot nanoparticles affect the reproductive system of Caenorhabditis elegans.

    PubMed

    Hsu, Pei-Chun L; O'Callaghan, Maureen; Al-Salim, Najeh; Hurst, Mark R H

    2012-10-01

    Quantum dots (QDs) are an increasingly important class of nanoparticle, but little ecotoxicological data for QDs has been published to date. The effects of mercaptosuccinic acid (MSA)-capped QDs (QDs-MSA) and equivalent concentrations of cadmium (Cd) from cadmium chloride on growth and reproduction of the nematode Caenorhabditis elegans (Rhabditidae) were assessed in laboratory experiments. Growth from larvae to adults of C. elegans was unaffected by exposure to 1 µM fluorescent QDs-MSA, but adults produced more embryos and laid them prematurely. Furthermore, C. elegans exposed to QDs-MSA (1 µM) showed a high percentage of embryo mortality (19.2 ± 0.5, p < 0.001, percentage ± standard deviation) compared with unexposed nematodes (11.6 ± 0.4). An egg-laying defect phenotype was also observed at high frequency in response to 1 µM QDs-MSA exposure (38.3 ± 3.6%, p < 0.01; control 10.0 ± 2.2%). This resulted in a reduced mean life span (20.5 ± 1.1 d, p < 0.05) compared with the control (24.6 ± 1.0 d). Cadmium also caused reduced life span in C. elegans, but a low incidence of egg-laying defects was observed, suggesting that Cd and QDs-MSA affected C. elegans by different mechanisms. Furthermore, egg-laying defects caused by QDs-MSA responded to the addition of the anticonvulsant ethosuximide and to a lesser extent to the neurotransmitter serotonin, suggesting that QDs-MSA might have disrupted motor neurons during the reproduction process.

  3. Injuries from Non-Retention in Gillnet Fisheries Suppress Reproductive Maturation in Escaped Fish

    PubMed Central

    Baker, Matthew R.; Swanson, Penny; Young, Graham

    2013-01-01

    Exploitation of fisheries resources has unintended consequences, not only in the bycatch and discard of non-target organisms, but also in damage to targeted fish that are injured by gear but not landed (non-retention). Delayed mortality due to non-retention represents lost reproductive potential in exploited stocks, while not contributing to harvest. Our study examined the physiological mechanisms by which delayed mortality occurs and the extent to which injuries related to disentanglement from commercial gear compromise reproductive success in spawning stocks of Pacific salmon (Oncorhynchus spp.). We found evidence for elevated stress in fish injured via non-retention in gillnet fisheries. Plasma cortisol levels correlated with the severity of disentanglement injury and were elevated in fish that developed infections related to disentanglement injuries. We also analyzed sex steroid concentrations in females (estradiol-17β and 17,20β-dihydroxy-4-pregnen-3-one) to determine whether non-retention impairs reproductive potential in escaped individuals. We demonstrate evidence for delayed or inhibited maturation in fish with disentanglement injuries. These findings have important implications for effective conservation and management of exploited fish stocks and suggest means to improve spawning success in such stocks if retention in commercial fisheries is improved and incidental mortality reduced. PMID:23894510

  4. Germ cell transplantation as a potential biotechnological approach to fish reproduction.

    PubMed

    Lacerda, S M S N; Costa, G M J; Campos-Junior, P H A; Segatelli, T M; Yazawa, R; Takeuchi, Y; Morita, T; Yoshizaki, G; França, L R

    2013-02-01

    Although the use of germ cell transplantation has been relatively well established in mammals, the technique has only been adapted for use in fish after entering the 2000s. During the last decade, several different approaches have been developed for germ cell transplantation in fish using recipients of various ages and life stages, such as blastula-stage embryos, newly hatched larvae and sexually mature specimens. As germ cells can develop into live organisms through maturation and fertilization processes, germ cell transplantation in fish has opened up new avenues of research in reproductive biotechnology and aquaculture. For instance, the use of xenotransplantation in fish has lead to advances in the conservation of endangered species and the production of commercially valuable fish using surrogated recipients. Further, this could also facilitate the engineering of transgenic fish. However, as is the case with mammals, knowledge regarding the basic biology and physiology of germline stem cells in fish remains incomplete, imposing a considerable limitation on the application of germ cell transplantation in fish. Furthering our understanding of germline stem cells would contribute significantly to advances regarding germ cell transplantation in fish.

  5. Fathead minnow (Pimephales promelas) reproduction is impaired in aged oil sands process-affected waters.

    PubMed

    Kavanagh, Richard J; Frank, Richard A; Oakes, Ken D; Servos, Mark R; Young, Rozlyn F; Fedorak, Phillip M; MacKinnon, Mike D; Solomon, Keith R; Dixon, D George; Van Der Kraak, Glen

    2011-01-17

    Large volumes of fluid tailings are generated during the extraction of bitumen from oil sands. As part of their reclamation plan, oil sands operators in Alberta propose to transfer these fluid tailings to end pit lakes and, over time, these are expected to develop lake habitats with productive capabilities comparable to natural lakes in the region. This study evaluates the potential impact of various oil sands process-affected waters (OSPW) on the reproduction of adult fathead minnow (Pimephales promelas) under laboratory conditions. Two separate assays with aged OPSW (>15 years) from the experimental ponds at Syncrude Canada Ltd. showed that water containing high concentrations of naphthenic acids (NAs; >25 mg/l) and elevated conductivity (>2000 μS/cm) completely inhibited spawning of fathead minnows and reduced male secondary sexual characteristics. Measurement of plasma sex steroid levels showed that male fathead minnows had lower concentrations of testosterone and 11-ketotestosterone whereas females had lower concentrations of 17β-estradiol. In a third assay, fathead minnows were first acclimated to the higher salinity conditions typical of OSPW for several weeks and then exposed to aged OSPW from Suncor Energy Inc. (NAs ∼40 mg/l and conductivity ∼2000 μS/cm). Spawning was significantly reduced in fathead minnows held in this effluent and male fathead minnows had lower concentrations of testosterone and 11-ketotestosterone. Collectively, these studies demonstrate that aged OSPW has the potential to negatively affect the reproductive physiology of fathead minnows and suggest that aquatic habitats with high NAs concentrations (>25 mg/l) and conductivities (>2000 μS/cm) would not be conducive for successful fish reproduction.

  6. The hypothalamic-pituitary-thyroid (HPT) axis in fish and its role in fish development and reproduction.

    PubMed

    Blanton, Michael L; Specker, Jennifer L

    2007-01-01

    Bony fishes represent the largest vertebrate class and are a very diverse animal group. This chapter provides a thorough review of the available scientific literature on the thyroid system in these important vertebrate animals. The molecular components of the hypothalamic-pituitary-thyroid (HPT) axis in this group correspond closely to those of mammals. The thyroid tissue in the fishes is organized as diffuse follicles, with a few exceptions, rather than as an encapsulated gland as is found in most other vertebrate species. The features of this diffuse tissue in fishes are reviewed with an emphasis on feedback relationships within the HPT axis, the molecular biology of the thyroid system in fishes, and comparisons versus the thyroid systems of other vertebrate taxa. A review of the role of thyroid hormone in fish development and reproduction is included. Available information about the HPT axis in fishes is quite detailed for some species and rather limited or absent in others. This review focuses on species that have been intensively studied for their value as laboratory models in assays to investigate disruption in normal function of the thyroid system. In addition, in vitro and in vivo assay methods for screening chemicals for their potential to interfere with the thyroid system are reviewed. It is concluded that there are currently no in vitro or in vivo assays in fish species that are sufficiently developed to warrant recommendation for use to efficiently screen chemicals for thyroid disruption. Methods are available that can be used to measure thyroid hormones, although our ability to interpret the causes and implications of potential alterations in T4 or T3 levels in fishes is nonetheless limited without further research.

  7. Reproductive effects on freshwater fish exposed to 17α-trenbolone and 17α-estradiol.

    PubMed

    Robinson, Joseph A; Staveley, Jane P; Constantine, Lisa

    2017-03-01

    17α-Trenbolone and 17α-estradiol are principal metabolites in cattle excreta following the administration of Synovex(®) ONE, which contains trenbolone acetate and estradiol benzoate. As part of the environmental assessment of the use of Synovex(®) ONE, data were generated to characterize the effects of 17α-trenbolone and 17α-estradiol on the reproduction of freshwater fish. These substances are known endocrine disruptors, so the purpose of testing was not to clarify these properties but to identify concentrations representing population-relevant effects for use in risk characterization. The short-term reproduction assay was conducted with 17α-trenbolone using the fathead minnow (Pimephales promelas) and the medaka (Oryzias latipes) and with 17α-estradiol using the fathead minnow. Adverse effects on the population-relevant endpoints of survival and fecundity were used to establish the no-observed-effect concentration (NOEC) and the lowest-observed-effect concentration (LOEC) for each study. For 17α-trenbolone, adverse effects on fecundity of the fathead minnow occurred at 120 ng/L; this was the LOEC, and the NOEC was 35 ng/L. 17β-Trenbolone did not adversely affect survival and fecundity of medaka at the concentrations tested, resulting in a NOEC of 110 ng/L and a LOEC of >110 ng/L. 17α-Estradiol did not adversely impact survival and fecundity of the fathead minnow at the concentrations tested, resulting in a NOEC and LOEC of 250 ng/L and >250 ng/L, respectively. Environ Toxicol Chem 2017;36:636-644. © 2016 SETAC.

  8. Reproductive seasonality of fishes from a lotic stretch of the Grande River, high Paraná river basin, Brazil.

    PubMed

    Andrade, P M; Braga, F M S

    2005-08-01

    We searched for correlations between water level, rainfall, temperature, and reproductive activity of fishes in a lotic stretch of the Grande River below the Volta Grande Dam. Gillnets were used to catch the fish on six field journeys made bimonthly between April 1998 and February 1999. Fish gonads were classified according to maturation grade and the amount of mature or spent gonads was correlated with rainfall and air temperature. Most fish species showed seasonal reproduction (between October and February). The relative frequency of fully mature and spent gonads significantly correlated with rainfall (Spearman r = 0.94, p = 0.005) and air temperature (r = 0.84, p = 0.036), showing the importance of these factors in regulating the reproductive cycle of fishes in this location. Nevertheless, dam operation resulted in minimal water level variation that did not significantly correlate with reproductive activity (r = -0.43, p = 0.396).

  9. Assessment of wastewater treatment plant effluent effects on fish reproduction

    EPA Science Inventory

    Wastewater treatment plant (WWTP) effluents are known contributors of chemical mixtures into the environment. Of particular concern are endocrine-disrupting compounds that can affect hypothalamic-pituitary-gonadal axis function in exposed organisms. The present study examined t...

  10. Identification of quantitative trait loci affecting reproduction in pigs.

    PubMed

    Cassady, J P; Johnson, R K; Pomp, D; Rohrer, G A; Van Vleck, L D; Spiegel, E K; Gilson, K M

    2001-03-01

    The objective of this research was to identify chromosomal regions harboring QTL affecting reproduction in pigs. A three-generation resource population was developed by crossing low-indexing pigs from a randomly selected control line (C) with high-indexing pigs of a line selected for increased index of ovulation rate and embryonic survival (I). Differences between Lines I and C at Generation 10 were 6.7 ova and 3.3 fetuses at 50 d of gestation and 3.1 fully formed and 1.6 live pigs at birth. Phenotypic data were collected on F2 females, born in three replicates, for ovulation rate (n = 423), age at puberty (n = 295), litter size (n = 370), and number of nipples (n = 428). Litter-size data included number of fully formed, live, stillborn, and mummified pigs. Grandparent, F1, and F2 animals were genotyped for 151 microsatellite markers distributed across all 18 autosomes and the X chromosome. Genotypic data were available on 423 F2 females. Average spacing between markers was 19.3 Kosambi centimorgans. Calculations of logarithms of odds (LOD) scores were by least squares, and fixed effects for sire-dam combination and replicate were included in the models. Genome-wide significance level thresholds of 5% and 10% were calculated using a permutation approach. There was evidence (P < 0.05) for QTL affecting ovulation rate on SSC9, age at puberty on SSC7 and SSC8, number of nipples on SSC8 and SSC11, number of stillborn pigs on SSC5 and SSC13, and number of fully formed pigs on SSC11. There was evidence (P < 0.10) for additional QTL affecting age at puberty on SSC7, SSC8, and SSC12, number born live on SSC11, and number of nipples on SSC1, SSC6, and SSC7. Litter size is lowly heritable and sex-limited. Therefore, accuracy of selection for litter size may be enhanced by marker-assisted selection. Ovulation rate and age at puberty are laborious to measure, and thus marker-assisted selection may provide a practical and efficient method of selection.

  11. Effects of dietary uranium on reproductive endpoints--fecundity, survival, reproductive success--of the fish Danio rerio.

    PubMed

    Simon, Olivier; Mottin, Elmina; Geffroy, Benjamin; Hinton, Thomas

    2011-01-01

    Exposure to metal-contaminated water has been shown to result in a number of reproductive abnormalities in adult and larvae fish, such as failure of oocyte maturation and teratogenic effects. Recently, dietary uptake of metals by fish has been recognized as a critical route of exposure, however, the mechanisms of metal uptake and toxicity are poorly understood and in need of further investigation. The objectives of the present study are to quantify uranium (U dietary transfers from spiked artificial diets) in Danio rerio tissues and embryos, as well as establish its effect on reproduction and embryonic development. Uranium's environmental prominence is currently increasing because of new mining and milling activities. Uranium concentrations range from 0.02 µg/L in natural waters to 2 mg/L. The focus of this study was to examine the trophic transfer and effects of U following exposure modalities (dose, exposure duration 1 to 20 d). Two different isotopes were used to distinguish between chemical and radioactivity toxicity of U. Results showed that U trophic transfer was low (0.52%). Uranium tissue distributions showed that accumulation occurred in digestive organs (liver, digestive tract) following dietary exposure. High levels of U were measured in the gonads (female in particular, >20% of relative burden). High U accumulation levels in eggs indicated maternal transfer of the contaminant. Moreover, U trophic exposure led to a reduction in reproduction success as a function of U accumulated levels. High U exposure conditions strongly reduced the total number of eggs (50%) and their viability at 10 d (reduction of the clutch number, low quality of eggs).

  12. Tracking Official Development Assistance for Reproductive Health in Conflict-Affected Countries

    PubMed Central

    Patel, Preeti; Roberts, Bayard; Guy, Samantha; Lee-Jones, Louise; Conteh, Lesong

    2009-01-01

    Background Reproductive health needs are particularly acute in countries affected by armed conflict. Reliable information on aid investment for reproductive health in these countries is essential for improving the efficiency and effectiveness of aid. The purpose of this study was to analyse official development assistance (ODA) for reproductive health activities in conflict-affected countries from 2003 to 2006. Methods and Findings The Creditor Reporting System and the Financial Tracking System databases were the chosen data sources for the study. ODA disbursement for reproductive health activities to 18 conflict-affected countries was analysed for 2003, 2004, 2005, and 2006. An average of US$20.8 billion in total ODA was disbursed annually to the 18 conflict-affected countries between 2003 and 2006, of which US$509.3 million (2.4%) was allocated to reproductive health. This represents an annual average of US$1.30 disbursed per capita in the 18 sampled countries for reproductive health activities. Non-conflict-affected least-developed countries received 53.3% more ODA for reproductive health activities than conflict-affected least-developed countries, despite the latter generally having greater reproductive health needs. ODA disbursed for HIV/AIDS prevention and treatment increased by 119.4% from 2003 to 2006. The ODA disbursed for other direct reproductive health activities declined by 35.9% over the same period. Conclusions This study provides evidence of inequity in disbursement of reproductive health ODA between conflict-affected countries and non-conflict-affected countries, and between different reproductive health activities. These findings and the study's recommendations seek to support initiatives to make aid financing more responsive to need in the context of armed conflict. PMID:19513098

  13. Effects of Norethindrone and Metabolite Ethynylestradiol on Reproductive Parameters in a Marine Fish

    EPA Science Inventory

    Norethindrone (NOR) is a progestin used in human contraceptives and has been detected in low concentrations (ng/L) in aquatic environments. Laboratory experiments were conducted with the marine fish cunner (Tautogolabrus adspersus) to evaluate whether NOR could affect reproductiv...

  14. Effects of Pharmaceuticals Used for Breast Cancer Treatment on Reproduction and Aromatase Activity in a Marine Fish

    EPA Science Inventory

    Laboratory experiments were conducted with the marine fish cunner (Tautogolabrus adspersus) to evaluate whether four pharmaceuticals used in breast cancer treatment have an impact on reproduction or aromatase activity. Tamoxifen binds to estrogen receptors, while anastrozole, let...

  15. Social regulation of male reproductive plasticity in an African cichlid fish.

    PubMed

    Maruska, Karen P; Fernald, Russell D

    2013-12-01

    Social interactions with the outcome of a position in a dominance hierarchy can have profound effects on reproductive behavior and physiology, requiring animals to integrate environmental information with their internal physiological state; but how is salient information from the animal's dynamic social environment transformed into adaptive behavioral, physiological, and molecular-level changes? The African cichlid fish, Astatotilapia burtoni, is ideally suited to understand socially controlled reproductive plasticity because activity of the male reproductive (brain-pituitary-gonad) axis is tightly linked to social status. Males form hierarchies in which a small percentage of brightly colored dominant individuals have an active reproductive axis, defend territories, and spawn with females, while the remaining males are subordinate, drably colored, do not hold a territory, and have a suppressed reproductive system with minimal opportunities for spawning. These social phenotypes are plastic and quickly reversible, meaning that individual males may switch between dominant and subordinate status multiple times within a lifetime. Here, we review the rapid and remarkable plasticity that occurs along the entire reproductive axis when males rise in social rank, a transition that has important implications for the operational sex ratio of the population. When males rise in rank, transformations occur in the brain, pituitary, circulation, and testes over short time-scales (minutes to days). Changes are evident in overt behavior, as well as modifications at the physiological, cellular, and molecular levels that regulate reproductive capacity. Widespread changes triggered by a switch in rank highlight the significance of external social information in shaping internal physiology and reproductive competence.

  16. Optimal reproduction in salmon spawning substrates linked to grain size and fish length

    NASA Astrophysics Data System (ADS)

    Riebe, Clifford S.; Sklar, Leonard S.; Overstreet, Brandon T.; Wooster, John K.

    2014-02-01

    Millions of dollars are spent annually on revitalizing salmon spawning in riverbeds where redd building by female salmon is inhibited by sediment that is too big for fish to move. Yet the conditions necessary for productive spawning remain unclear. There is no gauge for quantifying how grain size influences the reproductive potential of coarse-bedded rivers. Hence, managers lack a quantitative basis for optimizing spawning habitat restoration for reproductive value. To overcome this limitation, we studied spawning by Chinook, sockeye, and pink salmon (Oncorhynchus tshawytscha, O. nerka, and O. gorbuscha) in creeks and rivers of California and the Pacific Northwest. Our analysis shows that coarse substrates have been substantially undervalued as spawning habitat in previous work. We present a field-calibrated approach for estimating the number of redds and eggs a substrate can accommodate from measurements of grain size and fish length. Bigger fish can move larger sediment and thus use more riverbed area for spawning. They also tend to have higher fecundity, and so can deposit more eggs per redd. However, because redd area increases with fish length, the number of eggs a substrate can accommodate is maximized for moderate-sized fish. This previously unrecognized tradeoff raises the possibility that differences in grain size help regulate river-to-river differences in salmon size. Thus, population diversity and species resilience may be linked to lithologic, geomorphic, and climatic factors that determine grain size in rivers. Our approach provides a tool for managing grain-size distributions in support of optimal reproductive potential and species resilience.

  17. Legal issues affecting confidentiality and informed consent in reproductive health.

    PubMed

    Rockett, L R

    2000-01-01

    The law governing confidentiality and informed consent has acquired unique characteristics in the area of reproductive health, as a consequence of both the establishment of a constitutional right to privacy in reproductive health matters and the reaction of those politically and morally opposed to the exercise of that right. The primary issues have involved: 1) the right of minors to receive reproductive health services without parental consent, which remains a political battleground; 2) laws requiring physicians to provide information to pregnant patients that is intended, not to inform them of the risks and benefits of the procedure, but to discourage them from obtaining abortions; 3) coerced and prohibited sterilizations; 4) court-ordered contraception and procedures to protect the fetus; and 5) restrictions on counseling about abortion, contraception, sterilization, and other reproductive health services authorized by state conscience or noncompliance clauses that shield such restrictions from the usual ethical, medical, and legal rules governing informed consent. The last area is of profound significance to the ability of women to make informed decisions about their reproductive health options. In the current economic environment, which fuels mergers and acquisitions involving sectarian and nonsectarian institutions, women are increasingly being put at risk as a result of such restrictions.

  18. Demographic and reproductive plasticity across the depth distribution of a coral reef fish

    PubMed Central

    Goldstein, Esther D.; D’Alessandro, Evan K.; Sponaugle, Su

    2016-01-01

    As humans expand into natural environments, populations of wild organisms may become relegated to marginal habitats at the boundaries of their distributions. In the ocean, mesophotic coral ecosystems (30–150 m) at the depth limit of photosynthetic reefs are hypothesized to act as refuges that are buffered from anthropogenic and natural disturbances, yet the viability and persistence of subpopulations in these peripheral habitats remains poorly understood. To assess the potential for mesophotic reefs to support robust coral reef fish populations, we compared population density and structure, growth, size, and reproductive output of the bicolor damselfish (Stegastes partitus) from shallow (<10 m), deep shelf (20–30 m), and mesophotic reefs (60–70 m) across the Florida Platform. Population densities decreased and size and age distributions shifted toward older and larger individuals in deeper habitats. Otolith-derived ages indicated that S. partitus found on mesophotic reefs reach larger asymptotic sizes and have longer lifespans than fish in shallower habitats. Based on measurements of oocyte area and batch fecundity, mesophotic fish also have higher reproductive investment. These demographic patterns indicate that mesophotic fish populations composed of large, fecund individuals produce high condition larvae and rely on longevity of individuals for population persistence and viability. PMID:27677948

  19. Neurokinin B and reproductive functions: "KNDy neuron" model in mammals and the emerging story in fish.

    PubMed

    Hu, Guangfu; Lin, Chengyuan; He, Mulan; Wong, Anderson O L

    2014-11-01

    In mammals, neurokinin B (NKB), the gene product of the tachykinin family member TAC3, is known to be a key regulator for episodic release of luteinizing hormone (LH). Its regulatory actions are mediated by a subpopulation of kisspeptin neurons within the arcuate nucleus with co-expression of NKB and dynorphin A (commonly called the "KNDy neurons"). By forming an "autosynaptic feedback loop" within the hypothalamus, the KNDy neurons can modulate gonadotropin-releasing hormone (GnRH) pulsatility and subsequent LH release in the pituitary. NKB regulation of LH secretion has been recently demonstrated in zebrafish, suggesting that the reproductive functions of NKB may be conserved from fish to mammals. Interestingly, the TAC3 genes in fish not only encode the mature peptide of NKB but also a novel tachykinin-like peptide, namely NKB-related peptide (or neurokinin F). Recent studies in zebrafish also reveal that the neuroanatomy of TAC3/kisspeptin system within the fish brain is quite different from that of mammals. In this article, the current ideas of "KNDy neuron" model for GnRH regulation and steroid feedback, other reproductive functions of NKB including its local actions in the gonad and placenta, the revised model of tachykinin evolution from invertebrates to vertebrates, as well as the emerging story of the two TAC3 gene products in fish, NKB and NKB-related peptide, will be reviewed with stress on the areas with interesting questions for future investigations.

  20. Influences of acid mine drainage and thermal enrichment on stream fish reproduction and larval survival

    USGS Publications Warehouse

    Hafs, Andrew W.; Horn, C.D.; Mazik, P.M.; Hartman, K.J.

    2010-01-01

    Potential effects of acid mine drainage (AMD) and thermal enrichment on the reproduction of fishes were investigated through a larval-trapping survey in the Stony River watershed, Grant County, WV. Trapping was conducted at seven sites from 26 March to 2 July 2004. Overall larval catch was low (379 individuals in 220 hours of trapping). More larval White Suckers were captured than all other species. Vectors fitted to nonparametric multidimensional scaling ordinations suggested that temperature was highly correlated to fish communities captured at our sites. Survival of larval Fathead Minnows was examined in situ at six sites from 13 May to 11 June 2004 in the same system. Larval survival was lower, but not significantly different between sites directly downstream of AMD-impacted tributaries (40% survival) and non-AMD sites (52% survival). The lower survival was caused by a significant mortality event at one site that coincided with acute pH depression in an AMD tributary immediately upstream of the site. Results from a Cox proportional hazard test suggests that low pH is having a significant negative influence on larval fish survival in this system. The results from this research indicate that the combination of low pH events and elevated temperature are negatively influencing the larval fish populations of the Stony River watershed. Management actions that address these problems would have the potential to substantially increase both reproduction rates and larval survival, therefore greatly enhancing the fishery.

  1. A controllable on-off strategy for the reproductive containment of fish

    PubMed Central

    Zhang, Yunsheng; Chen, Ji; Cui, Xiaojuan; Luo, Daji; Xia, Hui; Dai, Jun; Zhu, Zuoyan; Hu, Wei

    2015-01-01

    A major impediment to the commercialization and cultivation of transgenic fish is the potential ecological risks they pose to natural environments: a problem that could be solved by the production of sterile transgenic fish. Here, we have developed an on-off reproductive containment strategy for fish that renders the offspring sterile but leaves their parents fertile. TG1 (Tol2-CMV-GFP-pA-CMV-gal4-pA-Tol2) and TG2 (Tol2-CMV-RFP-pA-5 × UAS-as/dnd-pA-Tol2) zebrafish lines were established using a GAL4/UAS system. While the parental lines remained fertile, in the hybrid offspring, GAL4 induced 5 × UAS to drive the transcription of antisense dnd, which significantly down-regulated endogenous dnd expression. This disrupted the migration of primordial germ cells (PGCs), led to their apoptosis, and resulted in few or no PGCs migrating to the genital ridge. This process induced sterility or reduced fertility in adult fish. This on-off strategy is a potentially effective means of generating sterile fish for commercialization while retaining fertility in brood stocks, and offers a novel method to mitigate the ecological risks of fish introductions. PMID:25556821

  2. Marine reserves and reproductive biomass: a case study of a heavily targeted reef fish.

    PubMed

    Taylor, Brett M; McIlwain, Jennifer L; Kerr, Alexander M

    2012-01-01

    Recruitment overfishing (the reduction of a spawning stock past a point at which the stock can no longer replenish itself) is a common problem which can lead to a rapid and irreversible fishery collapse. Averting this disaster requires maintaining a sufficient spawning population to buffer stochastic fluctuations in recruitment of heavily harvested stocks. Optimal strategies for managing spawner biomass are well developed for temperate systems, yet remain uncertain for tropical fisheries, where the danger of collapse from recruitment overfishing looms largest. In this study, we explored empirically and through modeling, the role of marine reserves in maximizing spawner biomass of a heavily exploited reef fish, Lethrinus harak around Guam, Micronesia. On average, spawner biomass was 16 times higher inside the reserves compared with adjacent fished sites. Adult density and habitat-specific mean fish size were also significantly greater. We used these data in an age-structured population model to explore the effect of several management scenarios on L. harak demography. Under minimum-size limits, unlimited extraction and all rotational-closure scenarios, the model predicts that preferential mortality of larger and older fish prompt dramatic declines in spawner biomass and the proportion of male fish, as well as considerable declines in total abundance. For rotational closures this occurred because of the mismatch between the scales of recovery and extraction. Our results highlight how alternative management scenarios fall short in comparison to marine reserves in preserving reproductively viable fish populations on coral reefs.

  3. A controllable on-off strategy for the reproductive containment of fish.

    PubMed

    Zhang, Yunsheng; Chen, Ji; Cui, Xiaojuan; Luo, Daji; Xia, Hui; Dai, Jun; Zhu, Zuoyan; Hu, Wei

    2015-01-05

    A major impediment to the commercialization and cultivation of transgenic fish is the potential ecological risks they pose to natural environments: a problem that could be solved by the production of sterile transgenic fish. Here, we have developed an on-off reproductive containment strategy for fish that renders the offspring sterile but leaves their parents fertile. TG1 (Tol2-CMV-GFP-pA-CMV-gal4-pA-Tol2) and TG2 (Tol2-CMV-RFP-pA-5 × UAS-as/dnd-pA-Tol2) zebrafish lines were established using a GAL4/UAS system. While the parental lines remained fertile, in the hybrid offspring, GAL4 induced 5 × UAS to drive the transcription of antisense dnd, which significantly down-regulated endogenous dnd expression. This disrupted the migration of primordial germ cells (PGCs), led to their apoptosis, and resulted in few or no PGCs migrating to the genital ridge. This process induced sterility or reduced fertility in adult fish. This on-off strategy is a potentially effective means of generating sterile fish for commercialization while retaining fertility in brood stocks, and offers a novel method to mitigate the ecological risks of fish introductions.

  4. Genetic mating systems and reproductive natural histories of fishes: lessons for ecology and evolution.

    PubMed

    Avise, John C; Jones, Adam G; Walker, DeEtte; DeWoody, J Andrew

    2002-01-01

    Fish species have diverse breeding behaviors that make them valuable for testing theories on genetic mating systems and reproductive tactics. Here we review genetic appraisals of paternity and maternity in wild fish populations. Behavioral phenomena quantified by genetic markers in various species include patterns of multiple mating by both sexes; frequent cuckoldry by males and rare cuckoldry by females in nest-tending species; additional routes to surrogate parentage via nest piracy and egg-thievery; egg mimicry by nest-tending males; brood parasitism by helper males in cooperative breeders; clutch mixing in oral brooders; kinship in schooling fry of broadcast spawners; sperm storage by dams in female-pregnant species; and sex-role reversal, polyandry, and strong sexual selection on females in some male-pregnant species. Additional phenomena addressed by genetic parentage analyses in fishes include clustered mutations, filial cannibalism, and local population size. All results are discussed in the context of relevant behavioral and evolutionary theory.

  5. The Role of Melatonin as a Hormone and an Antioxidant in the Control of Fish Reproduction

    PubMed Central

    Maitra, Saumen Kumar; Hasan, Kazi Nurul

    2016-01-01

    Reproduction in most fish is seasonal or periodic, and the spawning occurs in an appropriate season to ensure maximum survival of the offspring. The sequence of reproductive events in an annual cycle is largely under the control of a species-specific endogenous timing system, which essentially relies on a well-equipped physiological response mechanism to changing environmental cues. The duration of solar light or photoperiod is one of the most predictable environmental signals used by a large number of animals including fish to coordinate their seasonal breeding. In vertebrates, the pineal gland is the major photoneuroendocrine part of the brain that rhythmically synthesizes and releases melatonin (N-acetyl-5-methoxytryptamine) into the circulation in synchronization with the environmental light–dark cycle. Past few decades witnessed an enormous progress in understanding the mechanisms by which melatonin regulates seasonal reproduction in fish and in other vertebrates. Most studies emphasized hormonal actions of melatonin through its high-affinity, pertussis toxin-sensitive G-protein (guanine nucleotide-binding protein)-coupled receptors on the hypothalamus–pituitary–gonad (HPG) axis of fish. However, the discovery that melatonin due to its lipophilic nature can easily cross the plasma membrane of all cells and may act as a potent scavenger of free radicals and stimulant of different antioxidants added a new dimension to the idea explaining mechanisms of melatonin actions in the regulation of ovarian functions. The basic concept on the actions of melatonin as an antioxidant emerged from mammalian studies. Recently, however, some new studies clearly suggested that melatonin, apart from playing the role of a hormone, may also be associated with the reduction in oxidative stress to augment ovarian functions during spawning. This review thus aims to bring together the current knowledge on the role of melatonin as a hormone as well as an antioxidant in the control

  6. The Role of Melatonin as a Hormone and an Antioxidant in the Control of Fish Reproduction.

    PubMed

    Maitra, Saumen Kumar; Hasan, Kazi Nurul

    2016-01-01

    Reproduction in most fish is seasonal or periodic, and the spawning occurs in an appropriate season to ensure maximum survival of the offspring. The sequence of reproductive events in an annual cycle is largely under the control of a species-specific endogenous timing system, which essentially relies on a well-equipped physiological response mechanism to changing environmental cues. The duration of solar light or photoperiod is one of the most predictable environmental signals used by a large number of animals including fish to coordinate their seasonal breeding. In vertebrates, the pineal gland is the major photoneuroendocrine part of the brain that rhythmically synthesizes and releases melatonin (N-acetyl-5-methoxytryptamine) into the circulation in synchronization with the environmental light-dark cycle. Past few decades witnessed an enormous progress in understanding the mechanisms by which melatonin regulates seasonal reproduction in fish and in other vertebrates. Most studies emphasized hormonal actions of melatonin through its high-affinity, pertussis toxin-sensitive G-protein (guanine nucleotide-binding protein)-coupled receptors on the hypothalamus-pituitary-gonad (HPG) axis of fish. However, the discovery that melatonin due to its lipophilic nature can easily cross the plasma membrane of all cells and may act as a potent scavenger of free radicals and stimulant of different antioxidants added a new dimension to the idea explaining mechanisms of melatonin actions in the regulation of ovarian functions. The basic concept on the actions of melatonin as an antioxidant emerged from mammalian studies. Recently, however, some new studies clearly suggested that melatonin, apart from playing the role of a hormone, may also be associated with the reduction in oxidative stress to augment ovarian functions during spawning. This review thus aims to bring together the current knowledge on the role of melatonin as a hormone as well as an antioxidant in the control of

  7. Reproductive sharing in relation to group and colony-level attributes in a cooperative breeding fish

    PubMed Central

    Hellmann, Jennifer K.; Ligocki, Isaac Y.; O'Connor, Constance M.; Reddon, Adam R.; Garvy, Kelly A.; Marsh-Rollo, Susan E.; Gibbs, H. Lisle; Balshine, Sigal; Hamilton, Ian M.

    2015-01-01

    The degree to which group members share reproduction is dictated by both within-group (e.g. group size and composition) and between-group (e.g. density and position of neighbours) characteristics. While many studies have investigated reproductive patterns within social groups, few have simultaneously explored how within-group and between-group social structure influence these patterns. Here, we investigated how group size and composition, along with territory density and location within the colony, influenced parentage in 36 wild groups of a colonial, cooperatively breeding fish Neolamprologus pulcher. Dominant males sired 76% of offspring in their group, whereas dominant females mothered 82% of offspring in their group. Subordinate reproduction was frequent, occurring in 47% of sampled groups. Subordinate males gained more paternity in groups located in high-density areas and in groups with many subordinate males. Dominant males and females in large groups and in groups with many reproductively mature subordinates had higher rates of parentage loss, but only at the colony edge. Our study provides, to our knowledge, the first comprehensive quantification of reproductive sharing among groups of wild N. pulcher, a model species for the study of cooperation and social behaviour. Further, we demonstrate that the frequency of extra-pair parentage differs across small social and spatial scales. PMID:26136450

  8. Reproductive sharing in relation to group and colony-level attributes in a cooperative breeding fish.

    PubMed

    Hellmann, Jennifer K; Ligocki, Isaac Y; O'Connor, Constance M; Reddon, Adam R; Garvy, Kelly A; Marsh-Rollo, Susan E; Gibbs, H Lisle; Balshine, Sigal; Hamilton, Ian M

    2015-07-22

    The degree to which group members share reproduction is dictated by both within-group (e.g. group size and composition) and between-group(e.g. density and position of neighbours) characteristics. While many studies have investigated reproductive patterns within social groups, few have simultaneously explored how within-group and between-group social structure influence these patterns. Here, we investigated how group size and composition, along with territory density and location within the colony, influenced parentage in 36 wild groups of a colonial, cooperatively breeding fish Neolamprologus pulcher. Dominant males sired 76% of offspring in their group, whereas dominant females mothered 82% of offspring in their group. Subordinate reproduction was frequent, occurring in 47% of sampled groups. Subordinate males gained more paternity in groups located in high-density areas and in groups with many subordinate males. Dominant males and females in large groups and in groups with many reproductively mature subordinates had higher rates of parentage loss, but only at the colony edge. Our study provides, to our knowledge,the first comprehensive quantification of reproductive sharing among groups of wild N. pulcher, a model species for the study of cooperation and social behaviour. Further, we demonstrate that the frequency of extra-pair parentage differs across small social and spatial scales.

  9. Long-term cleaner fish presence affects growth of a coral reef fish

    PubMed Central

    Clague, Gillian E.; Cheney, Karen L.; Goldizen, Anne W.; McCormick, Mark I.; Waldie, Peter A.; Grutter, Alexandra S.

    2011-01-01

    Cleaning behaviour is considered to be a classical example of mutualism. However, no studies, to our knowledge, have measured the benefits to clients in terms of growth. In the longest experimental study of its kind, over an 8 year period, cleaner fish Labroides dimidiatus were consistently removed from seven patch reefs (61–285 m2) and left undisturbed on nine control reefs, and the growth and parasite load of the damselfish Pomacentrus moluccensis determined. After 8 years, growth was reduced and parasitic copepod abundance was higher on fish from removal reefs compared with controls, but only in larger individuals. Behavioural observations revealed that P. moluccensis cleaned by L. dimidiatus were 27 per cent larger than nearby conspecifics. The selective cleaning by L. dimidiatus probably explains why only larger P. moluccensis individuals benefited from cleaning. This is the first demonstration, to our knowledge, that cleaners affect the growth rate of client individuals; a greater size for a given age should result in increased fecundity at a given time. The effect of the removal of so few small fish on the size of another fish species is unprecedented on coral reefs. PMID:21733872

  10. External and internal controls of lunar-related reproductive rhythms in fishes.

    PubMed

    Takemura, A; Rahman, M S; Park, Y J

    2010-01-01

    Reproductive activities of many fish species are, to some extent, entrained to cues from the moon. During the spawning season, synchronous spawning is repeated at intervals of c. 1 month (lunar spawning cycle) and 2 weeks (semi-lunar spawning cycle) or daily according to tidal changes (tidal spawning cycle). In species showing lunar-related spawning cycles, oocytes in the ovary develop towards and mature around a specific moon phase for lunar spawners, around spring tides for semi-lunar spawners and at daytime high tides for tidal spawners. The production of sex steroid hormones also changes in accordance with synchronous oocyte development. Since the production of the steroid hormones with lunar-related reproductive periodicity is regulated by gonadotropins, it is considered that the higher parts of the hypothalamus-pituitary-gonad axis play important roles in the perception and regulation of lunar-related periodicity. It is likely that fishes perceive cues from the moon by sensory organs; however, it is still unknown how lunar cues are transduced as an endogenous rhythm exerting lunar-related spawning rhythmicity. Recent research has revealed that melatonin fluctuated according to the brightness at night, magnetic fields and the tidal cycle. In addition, cyclic changes in hydrostatic pressure had an effect on monoamine contents in the brain. These factors may be indirectly related to the exertion of lunar-related periodicity. Molecular approaches have revealed that mRNA expressions of light-sensitive clock genes change with moonlight, suggesting that brightness at night plays a role in phase-shifting or resetting of biological clocks. Some species may have evolved biological clocks in relation to lunar cycles, although it is still not known how lunar periodicities are endogenously regulated in fishes. This review demonstrates that lunar-related periodicity is utilized and incorporated by ecological and physiological mechanisms governing the reproductive success

  11. Derivation and evaluation of adverse outcome pathways for the effects of cyclooxygenase inhibitors on reproductive processes in fish

    EPA Science Inventory

    Cyclooxygenase (COX) inhibition is of concern in fish because COX inhibitors (e.g., ibuprofen) are ubiquitous in aquatic systems/fish tissues, and can disrupt synthesis of prostaglandins that modulate a variety of essential biological functions (e.g., reproduction). This study ut...

  12. An integrated omic analysis of hepatic alteration in medaka fish chronically exposed to cyanotoxins with possible mechanisms of reproductive toxicity.

    PubMed

    Qiao, Qin; Le Manach, Séverine; Huet, Hélène; Duvernois-Berthet, Evelyne; Chaouch, Soraya; Duval, Charlotte; Sotton, Benoit; Ponger, Loïc; Marie, Arul; Mathéron, Lucrèce; Lennon, Sarah; Bolbach, Gérard; Djediat, Chakib; Bernard, Cécile; Edery, Marc; Marie, Benjamin

    2016-12-01

    Cyanobacterial blooms threaten human health as well as the population of other living organisms in the aquatic environment, particularly due to the production of natural toxic components, the cyanotoxin. So far, the most studied cyanotoxins are microcystins (MCs). In this study, the hepatic alterations at histological, proteome and transcriptome levels were evaluated in female and male medaka fish chronically exposed to 1 and 5 μg L(-1) microcystin-LR (MC-LR) and to the extract of MC-producing Microcystis aeruginosa PCC 7820 (5 μg L(-1) of equivalent MC-LR) by balneation for 28 days, aiming at enhancing our understanding of the potential reproductive toxicity of cyanotoxins in aquatic vertebrate models. Indeed, both MC and Microcystis extract adversely affect reproductive parameters including fecundity and egg hatchability. The liver of toxin treated female fish present glycogen storage loss and cellular damages. The quantitative proteomics analysis revealed that the quantities of 225 hepatic proteins are dysregulated. In particular, a notable decrease in protein quantities of vitellogenin and choriogenin was observed, which could explain the decrease in reproductive output. Liver transcriptome analysis through Illumina RNA-seq reveals that over 100-400 genes are differentially expressed under 5 μg L(-1) MC-LR and Microcystis extract treatments, respectively. Ingenuity pathway analysis of the omic data attests that various metabolic pathways, such as energy production, protein biosynthesis and lipid metabolism, are disturbed by both MC-LR and the Microcystis extract, which could provoke the observed reproductive impairment. The transcriptomics analysis also constitutes the first report of the impairment of circadian rhythm-related gene induced by MCs. This study contributes to a better understanding of the potential consequences of chronic exposure of fish to environmental concentrations of cyanotoxins, suggesting that Microcystis extract could impact a

  13. Challenges and opportunities with the use of biomarkers to predict reproductive impairment in fishes exposed to endocrine disrupting substances.

    PubMed

    Bosker, Thijs; Munkittrick, Kelly R; Maclatchy, Deborah L

    2010-10-01

    Biomarkers are commonly used as signposts to evaluate the potential of contaminants to disrupt the endocrine system. However, the relationship between responses in these biomarkers and whole organism endpoints that directly affect population status is not clearly understood. In this study, the relationship between egg production (a whole-organism endpoint which has been directly linked to population-level responses) and biomarkers (sex steroids, vitellogenin (VTG) and gonad size) is examined. Data were collected from short-term reproductive tests in which a wide variety of fish species were exposed to a suite of contaminants with known or unknown modes/mechanisms of action (MOA). The potential to use biomarkers as signposts was evaluated by determining the occurrence of false negatives (i.e., an effect in egg production was not accompanied by a biomarker response) and false positives (i.e., an effect in biomarkers was not followed by an effect in egg production). The quantitative relationships between biomarkers and egg production, and the ability to use these quantitative relationships to predict population-level responses based on modeling was also assessed. A suite of female biomarkers resulted in a relatively low occurrence of both false positives and negatives, indicating the potential for their use as signposts for reproductive effects via endocrine disruption. Egg production in short-term adult fish reproductive tests showed significant relationships to 17β-estradiol (E2), changes in female VTG levels, and relative female gonad size (gonadosomatic index; GSI). Weaker significant relationships were found between egg production and both VTG levels and GSI in males. However, use of these quantitative relationships to predict population-level effects are cautioned because of high levels of uncertainty. This study demonstrates that there are qualitative and quantitative relationships among biomarkers, regardless of fish species used or the MOA of contaminants

  14. Ghrelin: a metabolic signal affecting the reproductive system.

    PubMed

    Lorenzi, Teresa; Meli, Rosaria; Marzioni, Daniela; Morroni, Manrico; Baragli, Alessandra; Castellucci, Mario; Gualillo, Oreste; Muccioli, Giampiero

    2009-04-01

    Ghrelin, an acylated 28 amino acid gastric peptide, was isolated from the stomach as an endogenous ligand for growth hormone (GH) secretagogue receptor in 1999. Circulating ghrelin is mainly produced by specific cells in the stomach's oxyntic glands. Ghrelin potently stimulates GH release and food intake and exhibits diverse effects, including ones on glucose metabolism and on secretion and motility of the gastrointestinal tract. Besides these effects on food intake and energy homeostasis, ghrelin is also involved in controlling reproductive functions, and a role for it as a novel regulator of the hypothalamic-pituitary gonadal axis is clearly emerging. We review recent ghrelin research with emphasis on its roles in the reproductive axis.

  15. Evidence for harvest-induced maternal influences on the reproductive rates of fish populations.

    PubMed

    Venturelli, Paul A; Shuter, Brian J; Murphy, Cheryl A

    2009-03-07

    Knowledge of the relationship between the number of offspring produced (recruitment) and adult abundance is fundamental to forecasting the dynamics of an exploited population. Although small-scale experiments have documented the importance of maternal quality to offspring survival in plants and animals, the effects of this association on the recruitment dynamics of exploited populations are largely unknown. Here, we present results from both a simple population model and a meta-analysis of time-series data from 25 species of exploited marine fishes that suggest that a population of older, larger individuals has a higher maximum reproductive rate than an equivalent population of younger, smaller individuals, and that this difference increases with the reproductive lifespan of the population. These findings (i) establish an empirical link between population age structure and reproductive rate that is consistent with strong effects of maternal quality on population dynamics and (ii) provide further evidence that extended age structure is essential to the sustainability of many exploited fish stocks.

  16. Hybridogenetic Reproduction and Maternal Ancestry of Polyploid Iberian Fish: The Tropidophoxinellus Alburnoides Complex

    PubMed Central

    Carmona, J. A.; Sanjur, O. I.; Doadrio, I.; Machordom, A.; Vrijenhoek, R. C.

    1997-01-01

    Iberian minnows collectively known as the Tropidophoxinellus alburnoides STEINDACHNER complex comprise diploid and polyploid forms with highly female biased sex ratios. Previous investigators suggested that all-female clonal reproduction and interspecific hybridization may occur in this complex. We examined nuclear (allozymes) and cytoplasmic genes (mtDNA) to assess the evolutionary origins, relationships, and reproductive modes of T. alburnoides from western Spain. The multi-locus allozyme data clearly revealed the hybrid nature of all polyploid forms of this fish and some diploid forms as well. Diagnostic markers identified fish from the genus Leuciscus as the paternal ancestor of hybrids in the Duero and Guadiana River Basins. Additionally, analysis of nuclear markers revealed that hybridogenetic reproduction occurs in the diploid and triploid hybrids. The hybrids fully express the paternal Leuciscus genome and then discard it during oogenesis. Hybridogenetic ova contain only maternal nuclear genes and mtDNA from a non-hybrid T. alburnoides ancestor. Apparently diploid and triploid hybrids of T. alburnoides persist as sperm parasites on males of a sexually reproducing Leuciscus host species. PMID:9215902

  17. Evidence for harvest-induced maternal influences on the reproductive rates of fish populations

    PubMed Central

    Venturelli, Paul A.; Shuter, Brian J.; Murphy, Cheryl A.

    2008-01-01

    Knowledge of the relationship between the number of offspring produced (recruitment) and adult abundance is fundamental to forecasting the dynamics of an exploited population. Although small-scale experiments have documented the importance of maternal quality to offspring survival in plants and animals, the effects of this association on the recruitment dynamics of exploited populations are largely unknown. Here, we present results from both a simple population model and a meta-analysis of time-series data from 25 species of exploited marine fishes that suggest that a population of older, larger individuals has a higher maximum reproductive rate than an equivalent population of younger, smaller individuals, and that this difference increases with the reproductive lifespan of the population. These findings (i) establish an empirical link between population age structure and reproductive rate that is consistent with strong effects of maternal quality on population dynamics and (ii) provide further evidence that extended age structure is essential to the sustainability of many exploited fish stocks. PMID:19033140

  18. How reproductive ecology contributes to the spread of a globally invasive fish.

    PubMed

    Deacon, Amy E; Ramnarine, Indar W; Magurran, Anne E

    2011-01-01

    Invasive freshwater fish represent a major threat to biodiversity. Here, we first demonstrate the dramatic, human-mediated range expansion of the Trinidadian guppy (Poecilia reticulata), an invasive fish with a reputation for negatively impacting native freshwater communities. Next, we explore possible mechanisms that might explain successful global establishment of this species. Guppies, along with some other notable invasive fish species such as mosquitofish (Gambusia spp.), have reproductive adaptations to ephemeral habitats that may enable introductions of very small numbers of founders to succeed. The remarkable ability of single pregnant guppies to routinely establish viable populations is demonstrated using a replicated mesocosm set up. In 86% of cases, these populations persisted for two years (the duration of the experiment). Establishment success was independent of founder origin (high and low predation habitats), and there was no loss of behavioural performance amongst mesocosm juveniles. Behavioural "signatures" of the founding locality were, however, evident in mesocosm fish. Our results demonstrate that introductions consisting of a single individual can lead to thriving populations of this invasive fish and suggest that particular caution should be exercised when introducing this species, or other livebearers, to natural water bodies.

  19. How Reproductive Ecology Contributes to the Spread of a Globally Invasive Fish

    PubMed Central

    Deacon, Amy E.; Ramnarine, Indar W.; Magurran, Anne E.

    2011-01-01

    Invasive freshwater fish represent a major threat to biodiversity. Here, we first demonstrate the dramatic, human-mediated range expansion of the Trinidadian guppy (Poecilia reticulata), an invasive fish with a reputation for negatively impacting native freshwater communities. Next, we explore possible mechanisms that might explain successful global establishment of this species. Guppies, along with some other notable invasive fish species such as mosquitofish (Gambusia spp.), have reproductive adaptations to ephemeral habitats that may enable introductions of very small numbers of founders to succeed. The remarkable ability of single pregnant guppies to routinely establish viable populations is demonstrated using a replicated mesocosm set up. In 86% of cases, these populations persisted for two years (the duration of the experiment). Establishment success was independent of founder origin (high and low predation habitats), and there was no loss of behavioural performance amongst mesocosm juveniles. Behavioural “signatures” of the founding locality were, however, evident in mesocosm fish. Our results demonstrate that introductions consisting of a single individual can lead to thriving populations of this invasive fish and suggest that particular caution should be exercised when introducing this species, or other livebearers, to natural water bodies. PMID:21957449

  20. Acute exposure to gas-supersaturated water does not affect reproductive success of female adult chinook salmon late in maturation

    USGS Publications Warehouse

    Gale, William L.; Maule, A.G.; Postera, A.; Peters, M.H.

    2004-01-01

    At times, total dissolved gas concentrations in the Columbia and Snake rivers have been elevated due to involuntary spill from high spring runoff and voluntary spill used as a method to pass juvenile salmonids over dams. The goal of this project was to determine if acute exposure to total dissolved gas supersaturation (TDGS) affects the reproductive performance of female chinook salmon late in their maturation. During this study, adult female spring chinook salmon were exposed to mean TDGS levels of 114.1 % to 125.5%. We ended exposures at first mortality, or at the appearance of impending death. Based on this criterion, exposures lasted from 10 to 68 h and were inversely related to TDGS. There was no effect of TDGS on pre-spawning mortality or fecundity when comparing treatment fish to experimental controls or the general hatchery population four to six weeks after exposures. Egg quality, based on egg weight and egg diameter, did not differ between treatment and control fish. Fertilization rate and survival to eyed-stage was high (>94%) for all groups. With the exception of Renibacterium salmoninarum (the causative agent of bacterial kidney disease; BKD), no viral or bacterial fish pathogens were isolated from experimental fish. The prevalence (about 45%) and severity of R. salmoninarum did not differ among the groups or the general hatchery population. We conclude that these acute exposures to moderate levels of gas-supersaturated water-perhaps similar to that experienced by immigrating adult salmon as they approach and pass a hydropower dam on the Columbia River-did not affect reproductive success of female chinook salmon late in their maturation. These results are most applicable to summer and fall chinook salmon, which migrate in the summer/fall and spawn shortly after reaching their natal streams. Published in 2004 by John Wiley and Sons, Ltd.

  1. Intersex and reproductive impairment of wild fish exposed to multiple municipal wastewater discharges.

    PubMed

    Tetreault, Gerald R; Bennett, Charles J; Shires, K; Knight, B; Servos, Mark R; McMaster, Mark E

    2011-08-01

    The Grand River watershed in Ontario, Canada, receives and assimilates the outflow of 29 Municipal Wastewater Effluent (MWWE) discharges which is a mixture of domestic and industrial wastes. The purpose of this study was to investigate the cumulative impact of multiple sewage discharges on populations of wild fish. In field studies, responses of fish populations and individual fish responses in terms of growth (condition factor), reproduction (in vitro sex steroid production, gonadosomatic indices, histology [cellular development and intersex]) were assessed upstream and downstream of two municipal discharges. Fish [Greenside Darters Etheostoma blennioides and Rainbow Darters E. caeruleum] collected downstream of two municipal wastewater plants had the potential to have greater growth (longer and heavier) when compared to reference fish collections regardless of sex. Fish were not assimilating additional anthropogenic resources into energy storage (increased condition, liver somatic index). Impacts on ovarian development appeared to be minor with no differences in growth, steroid production or cellular development. Sewage exposed male fish were experiencing impairment in the capacity to produce testosterone and 11-ketotestosterone in vitro, and in cellular development (GSI, intersex). Male darters of both species collected in the upstream agricultural region demonstrated no evidence of intersex whereas our urban reference sites had incidence of intersex of up to 20%. Rates of intersex were elevated downstream of both sewage discharges studied (33% and>60%, respectively). Lower rates of intersex at the intermediate sites, and then increases downstream of second sewage discharge suggests that fish populations have to potential to recover prior to exposure to the second sewage effluent. Pre-spawning darters demonstrated dramatically higher incidence of intersex in the spring at both urban reference sites (33% and 50%, respectively), and increased more so downstream of

  2. Assessing reproductive status in elasmobranch fishes using steroid hormones extracted from skeletal muscle tissue.

    PubMed

    Prohaska, Bianca K; Tsang, Paul C W; Driggers, William B; Hoffmayer, Eric R; Wheeler, Carolyn R; Brown, A Christine; Sulikowski, James A

    2013-01-01

    Elasmobranch fishes (sharks, skates, and rays) are particularly susceptible to anthropogenic threats, making a thorough understanding of their life history characteristics essential for proper management. Historically, elasmobranch reproductive data have been collected by lethal sampling, an approach that is problematic for threatened and endangered species. However, recent studies have demonstrated that non-lethal approaches can be as effective as lethal ones for assessment of the reproductive status of an animal. For example, plasma has been used to examine concentrations of steroid hormones. Additionally, skeletal muscle tissue, which can be obtained non-lethally and with minimal stress, can also be used to quantify concentrations of steroid hormones. Skeletal muscle progesterone, testosterone, and estradiol concentrations were determined to be statistically significant indicators of reproductive status in the oviparous Leucoraja erinacea, the yolk-dependent viviparous Squalus acanthias, and the yolk-sac placental viviparous Rhizoprionodon terraenovae. The results of the present study demonstrate that steroid hormones present in non-lethally harvested skeletal muscle tissue can be used as reliable indicators of reproductive status in elasmobranchs.

  3. Assessing reproductive status in elasmobranch fishes using steroid hormones extracted from skeletal muscle tissue

    PubMed Central

    Prohaska, Bianca K.; Tsang, Paul C. W.; Driggers, William B.; Hoffmayer, Eric R.; Wheeler, Carolyn R.; Brown, A. Christine; Sulikowski, James A.

    2013-01-01

    Elasmobranch fishes (sharks, skates, and rays) are particularly susceptible to anthropogenic threats, making a thorough understanding of their life history characteristics essential for proper management. Historically, elasmobranch reproductive data have been collected by lethal sampling, an approach that is problematic for threatened and endangered species. However, recent studies have demonstrated that non-lethal approaches can be as effective as lethal ones for assessment of the reproductive status of an animal. For example, plasma has been used to examine concentrations of steroid hormones. Additionally, skeletal muscle tissue, which can be obtained non-lethally and with minimal stress, can also be used to quantify concentrations of steroid hormones. Skeletal muscle progesterone, testosterone, and estradiol concentrations were determined to be statistically significant indicators of reproductive status in the oviparous Leucoraja erinacea, the yolk-dependent viviparous Squalus acanthias, and the yolk-sac placental viviparous Rhizoprionodon terraenovae. The results of the present study demonstrate that steroid hormones present in non-lethally harvested skeletal muscle tissue can be used as reliable indicators of reproductive status in elasmobranchs. PMID:27293612

  4. Survival, reproductive, and growth responses in fish to creosote exposure in aquatic mesocosms

    SciTech Connect

    Munro, K.A.; Solomon, K.R.; Bestari, K.T.; Robinson, R.D.

    1995-12-31

    Creosote is a coal tar distillate, consisting mainly of a mixture of polyaromatic hydrocarbons (PAHs). Its widespread use as a wood preservative presents a potential risk to aquatic ecosystems. The use of mesocosms (precolonized with zooplankton, phytoplankton, macroinvertebrates, and periphyton) enabled evaluation of the total impact of creosote exposure, resulting from both direct toxic effects and indirect community-level interactions. Two methods of creosote addition were used, resulting in two series of mesocosm exposures: sixteen ponds were dosed with liquid creosote (from 0 to 100 ppm), and eight were dosed using creosote impregnated pilings (0 to 6 pilings per pond). In addition to growth and survival in two species of fish, Carassius auratus and Pimephales promelas, a number of reproductive parameters were measured (reproductive hormones, egg production, hatching success, and weight/frequency distribution of juveniles).

  5. Oyster reproduction is affected by exposure to polystyrene microplastics.

    PubMed

    Sussarellu, Rossana; Suquet, Marc; Thomas, Yoann; Lambert, Christophe; Fabioux, Caroline; Pernet, Marie Eve Julie; Le Goïc, Nelly; Quillien, Virgile; Mingant, Christian; Epelboin, Yanouk; Corporeau, Charlotte; Guyomarch, Julien; Robbens, Johan; Paul-Pont, Ika; Soudant, Philippe; Huvet, Arnaud

    2016-03-01

    Plastics are persistent synthetic polymers that accumulate as waste in the marine environment. Microplastic (MP) particles are derived from the breakdown of larger debris or can enter the environment as microscopic fragments. Because filter-feeder organisms ingest MP while feeding, they are likely to be impacted by MP pollution. To assess the impact of polystyrene microspheres (micro-PS) on the physiology of the Pacific oyster, adult oysters were experimentally exposed to virgin micro-PS (2 and 6 µm in diameter; 0.023 mg·L(-1)) for 2 mo during a reproductive cycle. Effects were investigated on ecophysiological parameters; cellular, transcriptomic, and proteomic responses; fecundity; and offspring development. Oysters preferentially ingested the 6-µm micro-PS over the 2-µm-diameter particles. Consumption of microalgae and absorption efficiency were significantly higher in exposed oysters, suggesting compensatory and physical effects on both digestive parameters. After 2 mo, exposed oysters had significant decreases in oocyte number (-38%), diameter (-5%), and sperm velocity (-23%). The D-larval yield and larval development of offspring derived from exposed parents decreased by 41% and 18%, respectively, compared with control offspring. Dynamic energy budget modeling, supported by transcriptomic profiles, suggested a significant shift of energy allocation from reproduction to structural growth, and elevated maintenance costs in exposed oysters, which is thought to be caused by interference with energy uptake. Molecular signatures of endocrine disruption were also revealed, but no endocrine disruptors were found in the biological samples. This study provides evidence that micro-PS cause feeding modifications and reproductive disruption in oysters, with significant impacts on offspring.

  6. Oyster reproduction is affected by exposure to polystyrene microplastics

    PubMed Central

    Sussarellu, Rossana; Suquet, Marc; Thomas, Yoann; Lambert, Christophe; Fabioux, Caroline; Pernet, Marie Eve Julie; Le Goïc, Nelly; Quillien, Virgile; Mingant, Christian; Epelboin, Yanouk; Corporeau, Charlotte; Guyomarch, Julien; Robbens, Johan; Paul-Pont, Ika; Soudant, Philippe; Huvet, Arnaud

    2016-01-01

    Plastics are persistent synthetic polymers that accumulate as waste in the marine environment. Microplastic (MP) particles are derived from the breakdown of larger debris or can enter the environment as microscopic fragments. Because filter-feeder organisms ingest MP while feeding, they are likely to be impacted by MP pollution. To assess the impact of polystyrene microspheres (micro-PS) on the physiology of the Pacific oyster, adult oysters were experimentally exposed to virgin micro-PS (2 and 6 µm in diameter; 0.023 mg·L−1) for 2 mo during a reproductive cycle. Effects were investigated on ecophysiological parameters; cellular, transcriptomic, and proteomic responses; fecundity; and offspring development. Oysters preferentially ingested the 6-µm micro-PS over the 2-µm-diameter particles. Consumption of microalgae and absorption efficiency were significantly higher in exposed oysters, suggesting compensatory and physical effects on both digestive parameters. After 2 mo, exposed oysters had significant decreases in oocyte number (−38%), diameter (−5%), and sperm velocity (−23%). The D-larval yield and larval development of offspring derived from exposed parents decreased by 41% and 18%, respectively, compared with control offspring. Dynamic energy budget modeling, supported by transcriptomic profiles, suggested a significant shift of energy allocation from reproduction to structural growth, and elevated maintenance costs in exposed oysters, which is thought to be caused by interference with energy uptake. Molecular signatures of endocrine disruption were also revealed, but no endocrine disruptors were found in the biological samples. This study provides evidence that micro-PS cause feeding modifications and reproductive disruption in oysters, with significant impacts on offspring. PMID:26831072

  7. Temporal Dynamics of Reproduction of the Neotropical Fish, Crenicichla menezesi (Perciformes: Cichlidae)

    PubMed Central

    de Araújo, Andréa Soares; do Nascimento, Wallace Silva; Yamamoto, Maria Emília; Chellappa, Sathyabama

    2012-01-01

    The reproductive biology and the gonadal development cycle of the Neotropical cichlid fish, Crenicichla menezesi, is described. This species exhibits sexual dimorphism only during the spawning season. First sexual maturity of females is attained earlier than the males. Both macroscopic and histological investigations of ovaries and testes revealed four stages of gonadal maturation. Mean batch fecundity of females was 372 (±10,41) of mature oocytes. This species is a partial spawner, with an extended spawning period. Monthly values of GSI and the condition factor are negatively correlated during the gonadal development cycle of this species. PMID:22919339

  8. Temporal dynamics of reproduction of the neotropical fish, Crenicichla menezesi (Perciformes: Cichlidae).

    PubMed

    de Araújo, Andréa Soares; do Nascimento, Wallace Silva; Yamamoto, Maria Emília; Chellappa, Sathyabama

    2012-01-01

    The reproductive biology and the gonadal development cycle of the Neotropical cichlid fish, Crenicichla menezesi, is described. This species exhibits sexual dimorphism only during the spawning season. First sexual maturity of females is attained earlier than the males. Both macroscopic and histological investigations of ovaries and testes revealed four stages of gonadal maturation. Mean batch fecundity of females was 372 (± 10,41) of mature oocytes. This species is a partial spawner, with an extended spawning period. Monthly values of GSI and the condition factor are negatively correlated during the gonadal development cycle of this species.

  9. Reproductive health indicators of fishes from Pennsylvania watersheds: association with chemicals of emerging concern

    USGS Publications Warehouse

    Blazer, V.S.; Iwanowicz, D.D.; Walsh, H.L.; Sperry, A.J.; Iwanowicz, L.R.; Alvarez, D.A.; Brightbill, R.A.; Smith, G.; Foreman, W.T.; Manning, R.

    2014-01-01

    Fishes were collected at 16 sites within the three major river drainages (Delaware, Susquehanna, and Ohio) of Pennsylvania. Three species were evaluated for biomarkers of estrogenic/antiandrogenic exposure, including plasma vitellogenin and testicular oocytes in male fishes. Smallmouth bass Micropterus dolomieu, white sucker Catostomus commersonii, and redhorse sucker Moxostoma species were collected in the summer, a period of low flow and low reproductive activity. Smallmouth bass were the only species in which testicular oocytes were observed; however, measurable concentrations of plasma vitellogenin were found in male bass and white sucker. The percentage of male bass with testicular oocytes ranged from 10 to 100 %, with the highest prevalence and severity in bass collected in the Susquehanna drainage. The percentage of males with plasma vitellogenin ranged from 0 to 100 % in both bass and sucker. Biological findings were compared with chemical analyses of discrete water samples collected at the time of fish collections. Estrone concentrations correlated with testicular oocytes prevalence and severity and with the percentage of male bass with vitellogenin. No correlations were noted with the percentage of male sucker with vitellogenin and water chemical concentrations. The prevalence and severity of testicular oocytes in bass also correlated with the percent of agricultural land use in the watershed above a site. Two sites within the Susquehanna drainage and one in the Delaware were immediately downstream of wastewater treatment plants to compare results with upstream fish. The percentage of male bass with testicular oocytes was not consistently higher downstream; however, severity did tend to increase downstream.

  10. Challenges in current adult fish laboratory reproductive tests: suggestions for refinement using a mummichog (Fundulus heteroclitus) case study.

    PubMed

    Bosker, Thijs; Munkittrick, Kelly R; MacLatchy, Deborah L

    2009-11-01

    Concerns about screening endocrine-active contaminants have led to the development of a number of short-term fish reproductive tests. A review conducted of 62 published adult fish reproductive papers using various fish species found low samples sizes (mean of 5.7 replicates with a median of 5 replicates) and high variance (an average coefficient of variance of 43.8%). The high variances and low sample sizes allow only relatively large differences to be detected with the current protocols; the average significant difference detected was a 68.7% reduction in egg production, while only differences above 50% were detected with confidence. This result indicates low power to detect more subtle differences and a high probability of type II errors in interpretation. The present study identifies several ways to increase the power of the adult fish reproductive test in the mummichog (Fundulus heteroclitus). By identifying the peak timing of egg production (before and after the new moon), extending the duration of the experiment (increased from 7 to 14 d), and determining that a sample size of eight replicate tanks per treatment accurately predicts variance in the sample population (based on pre-exposure variation calculations of replicate tanks), the power of the test has been significantly increased. The present study demonstrates that weaknesses in the current adult fish reproductive tests can easily be addressed by focusing on improved understanding of the reproductive behavior of the test species and developing study designs that include calculating desired variability levels and increasing replicates.

  11. Prepartum nutritional strategy affects reproductive performance in dairy cows.

    PubMed

    Cardoso, F C; LeBlanc, S J; Murphy, M R; Drackley, J K

    2013-09-01

    Negative energy balance during early postpartum is associated with reduced reproductive performance in dairy cows. A pooled statistical analysis of 7 studies completed in our group from 1993 to 2010 was conducted to investigate the association between prepartum energy feeding regimen and reproductive performance. The interval from calving to pregnancy (days to pregnancy, DTP) was the dependent variable to assess reproductive performance. Individual data for 408 cows (354 multiparous and 54 primiparous) were included in the analysis. The net energy for lactation (NEL) intake was determined from each cow's average dry matter intake and calculated dietary NEL density. Treatments applied prepartum were classified as either controlled-energy (CE; limited NEL intake to ≤100% of requirement) or high-energy (HE; cows were allowed to consume >100%) diets fed during the far-off (FO) or close-up (CU) dry periods. Cow was the experimental unit. The Cox proportional hazard model revealed that days to pregnancy was shorter for CE (median=157 d) than HE (median=167 d) diets during the CU period [hazard ratio (HR)=0.70]. Cows fed HE diets during the last 4 wk prepartum lost more body condition score in the first 6 wk postpartum than those fed CE diets (-0.43 and -0.30, respectively). Cows fed CE diets during the FO period had lower nonesterified fatty acids concentrations in wk 1, 2, and 3 of lactation than cows fed HE diets. Higher nonesterified fatty acids concentration in wk 1 postpartum was associated with a greater probability of disease (n=251; odds ratio=1.18). Cows on the CE regimen during the FO period had greater plasma glucose concentrations during wk 1 and 3 after calving than cows fed the HE regimen. Higher plasma glucose (HG) concentration compared with lower glucose (LG) in wk 3 (HG: n=154; LG: n=206) and wk 4 (HG: n=71; LG: n=254) after calving was associated with shorter days to pregnancy (wk 3: median=151 and 171 d for HG and LG, respectively, and HR=1.3; wk 4

  12. Does Coxiella burnetii affect reproduction in cattle? A clinical update.

    PubMed

    Garcia-Ispierto, I; Tutusaus, J; López-Gatius, F

    2014-08-01

    Q fever is a zoonosis produced by Coxiella burnetii, a bacterium that is widely distributed worldwide. Domestic ruminants are the most important source of C. burnetii for human infection. In sheep and goats, abortion is the main clinical consequence of infection, yet the symptoms described in cattle have so far been inconsistent. Q fever has been also scarcely reported in cattle, most likely because of its difficult diagnosis at the farm level and because of the many existing responsible C. burnetii strains. In this report, the effects of C. burnetii infection or Q fever disease on the reproductive behaviour of dairy cattle are reviewed, with special emphasis placed on the scarcity of data available and possible control actions discussed.

  13. Microwave exposure affecting reproductive system in male rats.

    PubMed

    Kesari, Kavindra Kumar; Behari, Jitendra

    2010-09-01

    The object of present study is to investigate the effects of 50 GHz microwave frequency electromagnetic fields on reproductive system of male rats. Male rats of Wistar strain were used in the study. Animals 60 days old were divided into two groups--group I sham exposed and group II experimental (microwave exposed). During exposure, rats were confined in Plexiglas cages with drilled ventilation holes for 2 h a day for 45 days continuously at a specified specific absorption rate of 8.0 x 10(-4) W/kg. After the last exposure, the rats were sacrificed immediately and sperms were collected. Antioxidant enzyme (superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase), histone kinase, apoptosis, and cell cycle were analyzed in sperm cells. Result shows a significant decrease in the level of sperm GPx and SOD activity (p < or = 0.05), whereas catalase shows significant increase in exposed group of sperm samples as compared with control (p < 0.02). We observed a statistically significant decrease in mean activity of histone kinase as compared to the control (p < 0.016). The percentage of cells dividing in a spermatogenesis was estimated by analyzing DNA per cell by flow cytometry. The percentage of apoptosis in electromagnetic field exposed group shows increased ratio as compared to sham exposed (p < 0.004). There were no significant differences in the G(0)/G(1) phase; however, a significant decrease (p < 0.026) in S phase was obtained. Results also indicate a decrease in percentage of G(2)/M transition phase of cell cycle in exposed group as compared to sham exposed (p < 0.019). We conclude that these radiations may have a significant effect on reproductive system of male rats, which may be an indication of male infertility.

  14. Are fish immune systems really affected by parasites? an immunoecological study of common carp (Cyprinus carpio)

    PubMed Central

    2011-01-01

    Background The basic function of the immune system is to protect an organism against infection in order to minimize the fitness costs of being infected. According to life-history theory, energy resources are in a trade-off between the costly demands of immunity and other physiological demands. Concerning fish, both physiology and immunity are influenced by seasonal changes (i.e. temporal variation) associated to the changes of abiotic factors (such as primarily water temperature) and interactions with pathogens and parasites. In this study, we investigated the potential associations between the physiology and immunocompetence of common carp (Cyprinus carpio) collected during five different periods of a given year. Our sampling included the periods with temporal variability and thus, it presented a different level in exposure to parasites. We analyzed which of two factors, seasonality or parasitism, had the strongest impact on changes in fish physiology and immunity. Results We found that seasonal changes play a key role in affecting the analyzed measurements of physiology, immunity and parasitism. The correlation analysis revealed the relationships between the measures of overall host physiology, immunity and parasite load when temporal variability effect was removed. When analyzing separately parasite groups with different life-strategies, we found that fish with a worse condition status were infected more by monogeneans, representing the most abundant parasite group. The high infection by cestodes seems to activate the phagocytes. A weak relationship was found between spleen size and abundance of trematodes when taking into account seasonal changes. Conclusions Even if no direct trade-off between the measures of host immunity and physiology was confirmed when taking into account the seasonality, it seems that seasonal variability affects host immunity and physiology through energy allocation in a trade-off between life important functions, especially reproduction

  15. Does fish reproduction and metabolic activity influence metal levels in fish intestinal parasites, acanthocephalans, during fish spawning and post-spawning period?

    PubMed

    Filipović Marijić, Vlatka; Vardić Smrzlić, Irena; Raspor, Biserka

    2014-10-01

    Application of fish intestinal parasites, acanthocephalans, as bioindicators in metal exposure assessment usually involves estimation of their metal levels and bioconcentration factors. Metal levels in parasite final host, fishes, are influenced by fish physiology but there is no data for acanthocephalan metal levels. Gastrointestinal Zn, Fe, Mn, Cd, Ag levels in European chub (Squalius cephalus L.) from the Sava River were significantly higher during chub spawning (April/May) compared to the post-spawning period (September). In acanthocephalans (Pomphorhynchus laevis and Acanthocephalus anguillae) significantly higher metal levels during chub spawning were observed only for Zn in P. laevis. Bioconcentration factors were twice as high for Fe, Mn, Ag, Pb in the post-spawning period, probably as a consequence of lower gastrointestinal metal levels in fish rather than metal exposure. Therefore, bioconcentration factors should be interpreted with caution, due to their possible variability in relation to fish physiology. In addition, gastrointestinal Cu, Cd and Pb levels were lower in infected than uninfected chub, indicating that metal variability in fishes might be affected by the presence of acanthocephalans.

  16. Ocean acidification affects fish spawning but not paternity at CO2 seeps.

    PubMed

    Milazzo, Marco; Cattano, Carlo; Alonzo, Suzanne H; Foggo, Andrew; Gristina, Michele; Rodolfo-Metalpa, Riccardo; Sinopoli, Mauro; Spatafora, Davide; Stiver, Kelly A; Hall-Spencer, Jason M

    2016-07-27

    Fish exhibit impaired sensory function and altered behaviour at levels of ocean acidification expected to occur owing to anthropogenic carbon dioxide emissions during this century. We provide the first evidence of the effects of ocean acidification on reproductive behaviour of fish in the wild. Satellite and sneaker male ocellated wrasse (Symphodus ocellatus) compete to fertilize eggs guarded by dominant nesting males. Key mating behaviours such as dominant male courtship and nest defence did not differ between sites with ambient versus elevated CO2 concentrations. Dominant males did, however, experience significantly lower rates of pair spawning at elevated CO2 levels. Despite the higher risk of sperm competition found at elevated CO2, we also found a trend of lower satellite and sneaker male paternity at elevated CO2 Given the importance of fish for food security and ecosystem stability, this study highlights the need for targeted research into the effects of rising CO2 levels on patterns of reproduction in wild fish.

  17. Maternal characteristics and environment affect the costs of reproduction in female mountain goats.

    PubMed

    Hamel, Sandra; Côté, Steeve D; Festa-Bianchet, Marco

    2010-07-01

    Reproduction should reduce resources available for somatic investment and result in fundamental trade-offs among life-history traits. Using 18 years of longitudinal data from marked mountain goats (Oreamnos americanus), we assessed whether reproductive status affected female survival and future reproduction when accounting for parity, age, individual quality, population density, and environmental conditions. Reproduction reduced the probability of parturition and offspring survival in the following year. Female survival, however, was independent of previous reproduction, suggesting that females favored their own survival over that of their offspring. The lower probability of parturition in females that had a kid the previous year was only detected at high population density and among young and prime-aged females, suggesting that fitness costs of reproduction can be masked by variations in resource availability and individual characteristics. Primiparous females were less likely than multiparous females to reproduce in the subsequent year. Offspring survival was reduced at high density and after severe winters. Environmental conditions mainly influenced offspring survival, whereas female survival and fecundity were principally modulated by female characteristics. Our study highlights how different intrinsic and environmental factors can affect the probability of future reproduction and also underlines the value of long-term monitoring of known individuals.

  18. [Reproduction of the fish Gymnothorax equatorialis (Pisces: Muraenidae) in Jalisco and Colima, Mexico].

    PubMed

    Lucano-Ramírez, G; Ruiz-Ramírez, S; Rojo-Vázquez, J A; González-Sansón, G

    2008-03-01

    Reproduction of the fish Gymnothorax equatorialis (Pisces: Muraenidae) in Jalisco and Colima, Mexico. A total of 707 Gymnothorax equatorialis were collected monthly in the Jalisco and Colima coast, Mexico, from December 1995 to December 1998 and from August to November 1999, in order to determine their reproduction patterns. Females outnumbered and had longer bodies (mean length 54.7 cm) than males (52.1 cm). The minimum, maximum and mean values of total fecundity were respectively 9 660, 99 992 and 32 029 eggs. The total body length at which 50 percent of individuals have ripe gonads (L50) was 43.7 cm for females and 42.7 cm TL for males. Ovaries had two main types of oocytes: small inmature in cromatin nucleolus phase (85.1 microm) and large mature in secundary vitellogenesis phase (701.6 microm). High numbers of spermatozoa were observed in the seminal tubes of ripe testicles, which presented a lobular development. Based in gonad features and temporal changes in the gonad-somatic index, it is concluded that G. equatorialis has two relatively short reproduction periods (at the middle and at the end of the year).

  19. Gravid Spot Predicts Developmental Progress and Reproductive Output in a Livebearing Fish, Gambusia holbrooki

    PubMed Central

    Norazmi-Lokman, Nor Hakim; Purser, G. J.; Patil, Jawahar G.

    2016-01-01

    In most livebearing fish, the gravid spot is an excellent marker to identify brooding females, however its use to predict progress of embryonic development, brood size, timing of parturition and overall reproductive potential of populations remain unexplored. Therefore, to understand these relationships, this study quantified visual attributes (intensity and size) of the gravid spot in relation to key internal development in Gambusia holbrooki. Observations show that the colour of the gravid spot arises from progressive melanisation on the surface of the ovarian sac at its hind margin, rather than melanisation of the developing embryos or the skin of the brooding mother. More importantly, the gravid spot intensity and size were closely linked with both developmental stages and clutch size, suggesting their reliable use as external surrogates of key internal developmental in the species. Using predictive consistency of the gravid spot, we also determined the effect of rearing temperature (23°C and 25°C) on gestation period and parturition behaviour. The results show that gestation period was significantly reduced (F = 364.58; df = 1,48; P˃0.05) at 25°C. However there was no significant difference in average number of fry parturated in the two temperature groups (P<0.05), reaffirming that gravid spot intensity is a reliable predictor of reproductive output. The parturition in the species occurred predominantly in the morning and in contrast to earlier reports, tails of the fry emerged first with a few exceptions of head-first, twin and premature births. This study demonstrates utility of the gravid spot for downstream reproductive investigations in a live-bearing fish both in the field and laboratory. The reproducibility of the relationships (intensity with both developmental stage and clutch size), imply that they are also relevant to wild populations that experience varying temperature climes and stressors, significant deviations of which may serve as

  20. Fish short-term reproduction assay (FSTRA) with atrazine and the Japanese medaka (Oryzias latipes).

    PubMed

    Hosmer, Alan J; Schneider, Suzanne Z; Anderson, Julie C; Knopper, Loren D; Brain, Richard A

    2017-02-15

    Breeding groups of Japanese medaka (Oryzias latipes) were exposed to atrazine at measured concentrations of 0.6, 5.5, and 53 µg/L for 35 d. Evaluated endpoints included survival, fecundity, fertility, growth (weight and length), behavior, secondary sex characteristics (anal fin papillae), gonad histopathology, and hepatic vitellogenin. No statistically significant effects of atrazine exposure on survival and growth of medaka were noted during the test, and mean survival was ≥97.5% in all treatment groups on Day 35. No significant effects of atrazine exposure on reproduction were observed. The number of mean cumulative eggs produced in the negative control, 0.6, 5.5, and 53 µg/L treatment groups was 7158, 6691, 6883, and 6856 eggs, respectively. The mean number of eggs per female reproductive day was 40.9, 38.2, 40.2, and 39.2 eggs per day, respectively. There were also no dose-dependent effects on mean anal fin papillae counts among male fish or expression of vtg-II in males or females. In addition, atrazine exposure was not related to the development stage of test fish, with testes stages ranging from 2 to 3 in all groups and ovaries ranging from stage 2 to 2.5. Overall, exposure to atrazine up to 53 µg/L for 35 d did not result in significant, treatment-related effects on measured endpoints related to survival, growth, or reproduction in Japanese medaka. This article is protected by copyright. All rights reserved.

  1. Implant Size Availability Affects Reproduction of Distal Femoral Anatomy.

    PubMed

    Morris, William Z; Gebhart, Jeremy J; Goldberg, Victor M; Wera, Glenn D

    2016-07-01

    A total knee arthroplasty system offers more distal femoral implant anterior-posterior (AP) sizes than its predecessor. The purpose of this study is to investigate the impact of increased size availability on an implant system's ability to reproduce the AP dimension of the native distal femur. We measured 200 cadaveric femora with the AP-sizing guides of Zimmer (Warsaw, IN) NexGen (8 sizes) and Zimmer Persona (12 sizes) total knee arthroplasty systems. We defined "size deviation" as the difference in the AP dimension between the anatomic size of the native femur and the closest implant size. We defined satisfactory reproduction of distal femoral dimensions as < 1 mm difference between the implant and native femur size. The NexGen system was associated with a mean 0.46 mm greater implant size deviation than Persona (p < 0.001). When using a 1 mm size deviation as a cutoff for satisfactory replication of the native distal femoral anatomy, 85/200 specimens (42.5%) were a poor fit by NexGen, but a satisfactory fit by Persona. Only 1/200 specimens (0.5%) was a poor fit by Persona, but a satisfactory fit by NexGen (p < 0.001). The novel knee system with 12 versus 8 sizes reproduces the AP dimension of the native distal femur more closely than its predecessor. Further study is needed to determine the clinical impact of these differences.

  2. [A sociological study of factors affecting reproductive health of female teenagers and young women].

    PubMed

    Nizamov, I G; Chechulina, O V

    2003-01-01

    The reproductive health of teenagers deserves a special attention and must be regarded from the viewpoint of their future prospects as well as their social and cultural media. The mentioned social-and-cultural factors affecting the teenagers' attitude towards sexuality and preconditioning their access to information and services of healthcare have an impact on the status of their reproductive health and on their general well-being, including the ability of teenagers to avoid an undesired pregnancy or sexually transmitted diseases.

  3. Transient effects of methyltestosterone injection on different reproductive parameters of the hermaphrodite fish Kryptolebias marmoratus.

    PubMed

    Park, Chang-Beom; Soyano, Kiyoshi; Kiros, Solomon; Kitamura, Tomokazu; Minamiyama, Mizuhiko; Suzuki, Yutaka

    2013-09-01

    To elucidate the action mechanism of environmental androgenic chemicals on fish reproductive activity by transient stimulation in heavily polluted areas, individuals of the hermaphrodite fish Kryptolebias marmoratus were injected once with six concentrations of methyltestosterone (MT) (0.1, 1, 5, 10, 50, and 100 μg/g BW) intraperitoneally. The fish were sampled at intervals of 7, 15, and 30 days after a single injection. At 7 days after injection, mature oocytes were not observed in the MT-exposed groups except for the group exposed to 0.1 μg MT, while testicular development was not remarkably different between any of the groups. Also, at 7 days after injection, hepatic estrogen receptor α (ERα) and vitellogenin (VTG) mRNA abundance decreased significantly in the MT-exposed groups despite no significant difference in plasma 17β-estradiol (E2) levels between any of the groups. This significant difference in VTG mRNA between the control and the MT-exposed groups persisted until 30 days after injection, although ERα mRNA abundance was not statistically different between any groups at 30 days after injection. Our results clearly show that a single injection of MT inhibits ovarian development rather than testicular development in the hermaphroditic gonad of K. marmoratus. Furthermore, our results demonstrate that a single injection of MT interfered with hepatic VTG mRNA synthesis mediated by the suppression of hepatic ERα mRNA transcription.

  4. Reproduction and distribution of fishes in a cooling lake: Wisconsin power plant impact study

    SciTech Connect

    Rondorf, D.W.; Kitchell, J.F.

    1985-06-01

    Spatial and temporal patterns during reproduction and early-life history of fishes were studied in a manmade cooling lake. Lake Columbia, impounded in 1974, near Portage, Wisconsin, has an area of 190 ha, a mean depth of 2.1 m, and a 15C temperature gradient derived from the thermal effluent of a 527-MW fossil-fueled generating station that began operating in 1975. The lake was initially colonized by fishes when filled with Wisconsin River water. Observations suggest a decline of species diversity of the fish community due to direct action of upper lethal temperatures, absence of colonization by warm-water, lake-dwelling species, and lack of recruitment for certain species. Spatial and temporal patterns of spawning of black crappie were altered by a rapid rise in water temperatures following plant startup after a three-week shutdown. Elevated temperatures subsequently shortened the spawning season, induced resorption of ova, and caused loss of secondary sexual characteristics. After initially drifting with water current, juvenile stages of sunfish and gizzard shad responded to changes in the thermal gradient by horizontal and vertical shifts in abundance.

  5. Clonal Patch Size and Ramet Position of Leymus chinensis Affected Reproductive Allocation

    PubMed Central

    Zhang, Zhuo; Yang, Yunfei

    2015-01-01

    Reproductive allocation is critically important for population maintenance and usually varies with not only environmental factors but also biotic ones. As a typical rhizome clonal plant in China's northern grasslands, Leymus chinensis usually dominates the steppe communities and grows in clonal patches. In order to clarify the sexual reproductive allocation of L. chinensis in the process of the growth and expansion, we selected L. chinensis clonal patches of a range of sizes to examine the reproductive allocation and allometric growth of the plants. Moreover, the effects of position of L. chinensis ramets within the patch on their reproductive allocation were also examined. Clonal patch size and position both significantly affected spike biomass, reproductive tiller biomass and SPIKE/TILLER biomass ratio. From the central to the marginal zone, both the spike biomass and reproductive tiller biomass displayed an increasing trend in all the five patch size categories except for reproductive tiller biomass in 15–40m2 category. L. chinensis had significantly larger SPIKE/TILLER biomass ratio in marginal zone than in central zone of clonal patches that are larger than 15 m2 in area. Regression analysis showed that the spike biomass and SPIKE/TILLER biomass ratio were negatively correlated with clonal patch size while patch size showed significantly positive effect on SEED/SPIKE biomass ratio, but the reproductive tiller biomass and SEED/TILLER biomass ratio were not dependent on clonal patch size. The relationships between biomass of spike and reproductive tiller, between mature seed biomass and spike biomass and between mature seed biomass and reproductive tiller biomass were significant allometric for all or some of patch size categories, respectively. The slopes of all these allometric relationships were significantly different from 1. The allometric growth of L. chinensis is patch size-dependent. This finding will be helpful for developing appropriate practices for

  6. Mode of action of human pharmaceuticals in fish: the effects of the 5-alpha-reductase inhibitor, dutasteride, on reproduction as a case study.

    PubMed

    Margiotta-Casaluci, Luigi; Hannah, Robert E; Sumpter, John P

    2013-03-15

    In recent years, a growing number of human pharmaceuticals have been detected in the aquatic environment, generally at low concentrations (sub-ng/L-low μg/L). In most cases, these compounds are characterised by highly specific modes of action, and the evolutionary conservation of drug targets in wildlife species suggests the possibility that pharmaceuticals present in the environment may cause toxicological effects by acting through the same targets as they do in humans. Our research addressed the question of whether or not dutasteride, a pharmaceutical used to treat benign prostatic hyperplasia, may cause adverse effects in a teleost fish, the fathead minnow (Pimephales promelas), by inhibiting the activity of both isoforms of 5α-reductase (5αR), the enzyme that converts testosterone into dihydrotestosterone (DHT). Mammalian pharmacological and toxicological information were used to guide the experimental design and the selection of relevant endpoints, according to the so-called "read-across approach", suggesting that dutasteride may affect male fertility and steroid hormone dynamics. Therefore, a 21-day reproduction study was conducted to determine the effects of dutasteride (10, 32 and 100 μg/L) on fish reproduction. Exposure to dutasteride significantly reduced fecundity of fish and affected several aspects of reproductive endocrine functions in both males and females. However, none of the observed adverse effects occurred at concentrations of exposure lower than 32 μg/L; this, together with the low volume of drug prescribed every year (10.34 kg in the UK in 2011), and the extremely low predicted environmental concentration (0.03 ng/L), suggest that, at present, the potential presence of dutasteride in the environment does not represent a threat to wild fish populations.

  7. The reproduction in women affected by cooley disease

    PubMed Central

    Pafumi, Carlo; Leanza, Vito; Coco, Luana; Vizzini, Stefania; Ciotta, Lilliana; Messina, Alessandra; Leanza, Gianluca; Zarbo, Giuseppe; D'Agati, Alfio; Palumbo, Marco Antonio; Iemmola, Alessandra; Gulino, Ferdinando Antonio; Teodoro, Maria Cristina; Attard, Matthew; Plesca, Alina Cristina; Soares, Catarina; Kouloubis, Nina; Chammas, Mayada

    2011-01-01

    The health background management and outcomes of 5 pregnancies in 4 women affected by Cooley Disease, from Paediatric Institute of Catania University, are described, considering the preconceptual guidances and cares for such patients. These patients were selected among a group of 100 thalassemic women divided into three subgroups, according to their first and successive menstruation characteristics: i) patients with primitive amenorrhoea, ii) patients with secondary amenorrhoea and iii) patients with normal menstruation. Only one woman, affected by primitive amenorrhoea, needed the induction of ovulation. A precise and detailed pre-pregnancy assessment was effected before each conception. This was constituted by a series of essays, including checks for diabetes and hypothyroidism, for B and C hepatitis and for blood group antibodies. Moreover were evaluated: cardiac function, rubella immunity and transaminases. Other pregnancy monitoring, and cares during labour and delivery were effected according to usual obstetrics practice. All the women were in labour when she were 38 week pregnant, and the outcome were five healthy babies born at term, weighting between 2600 and 3200gs. The only complication was the Caesarean section. The improvements of current treatments, especially in the management of iron deposits, the prolongation of survival rate, will result in a continuous increase of pregnancies in thalassemic women. Pregnancy is now a real possibility for women affected by such disease. We are furthermore studying the possibility to collect the fetus' umbilical cord blood, after the delivery, to attempt eterologus transplantation to his mother trying to get a complete marrow reconstitution. PMID:22184526

  8. Mercurial induced changes in the hypothalamo-neurohypophysical complex in relation to reproduction in the teleostean fish

    SciTech Connect

    Ram, R.N.; Joy, K.P.

    1988-09-01

    Although extensive work has been done on neurotoxic, teratologic and genetic effects of mercurials in a variety of animals including man, very little is known about their impacts on the neuroendocrine physiology of reproduction. The available investigations largely pertain to mammals. However, reports on the toxic effects of longterm exposure to mercury compounds on physiology of reproduction are meagre in fish. In the present communication, inorganic mercuric chloride (HgCl/sub 2/) and organic mercurial fungicide (Emisan) induced changes in the hypothalamo-neurohypophysical system in relation to reproduction of C. punctatus are described after chronic exposure for 6 months.

  9. Major viral diseases affecting fish aquaculture in Spain.

    PubMed

    Pérez, S I; Rodríguez, S

    1997-06-01

    The number of viruses isolated from fish has grown in the last few years as a reflection of the increasing interest in fish diseases, particularly those occurring in aquaculture facilities. Of all the described viruses, only a few are considered to be of serious concern and economic importance; they are described in this review, drawing special attention to the four families of viruses (Birnaviridae, Rhabdoviridae, Iridoviridae and Reoviridae) that have been reported in Spanish aquaculture. Infectious pancreatic necrosis virus, a member of the first family, is the most spread virus with a prevalence of 39%. Viral diseases are untreatable and because effective and safe vaccines for fish are not yet commercially available, a great care needs to be exercised when moving fish or eggs from one site or country to another. Some fish health control regulations have been legislated in Europe and USA.

  10. Melatonin, But not auxin, affects postnatal reproductive development in the marsh rice rat (Oryzomys palustris).

    PubMed

    Edmonds, Kent E

    2013-06-01

    Melatonin and the plant hormone auxin (indole-3-acetic acid) have some structural similarity and, may thus exert comparable physiological effects on reproduction and growth. To test this possibility, I examined the effects of melatonin and auxin administration on reproductive and non-reproductive organ development in an animal model, the marsh rice rat Oryzomys palustris. Juvenile males housed under 14L:10D conditions were injected daily for four weeks with saline, melatonin, auxin, or melatonin and auxin, and the development of the testes and other organs was assessed. Melatonin alone significantly inhibited the development of the testes, seminal vesicles, Harderian glands, and overall somatic growth, but not the spleen. Auxin did not affect any endpoint measured. When melatonin was administered simultaneously with auxin, the melatonin effects dominated in suppressing reproduction and growth. The administration of melatonin or auxin in the drinking water produced results similar to the effects of melatonin and auxin injections reported herein. Lastly, both melatonin and auxin in the drinking water failed to alter any short photoperiod-induced reproductive inhibition. These data suggest that structural similarities between melatonin and auxin do not result in similar postnatal effects on reproductive and non-reproductive organ development on a long photoperiod and further suggest that melatonin and auxin do not operate through a common physiological mechanism.

  11. Altitude affects the reproductive performance in monoicous and dioicous bryophytes: examples from a Brazilian Atlantic rainforest

    PubMed Central

    Maciel-Silva, Adaíses S.; Marques Valio, Ivany F.; Rydin, Håkan

    2012-01-01

    Background and aims Short life cycles and trade-offs linked to breeding systems make bryophytes good models for the study of plant reproductive strategies. Our aim was to test if differences in sexual reproductive performance of bryophytes in tropical rainforests are driven by the breeding system of the species (monoicous or dioicous) or are mainly affected by the habitat. Methodology The reproductive performance (sexual branches, gametangia (sex organs), fertilization and sporophyte production) of 11 species was repeatedly monitored and analysed from populations at sea-level and montane sites of a Brazilian Atlantic rainforest over 15 months. Principal results Monoicous species had the highest reproductive performance, particularly for sexual branches, fertilized gametangia and sporophyte production. Species at the sea-level site produced more sexual branches and had more female-biased sex ratios of gametangia than species in the montane site. Fertilizations were more frequent at the montane site, but sporophyte frequency was similar between the two sites. Fertilization tended to occur mostly in the periods of heavy rain (October to December). Conclusions Breeding system is not the only major influence on the reproductive performance of bryophytes. We show that habitat is also an important factor determining life-history differentiation. Female-biased sex ratios and low rates of fertilization are seen to be compensated for by high production of reproductive structures at the initial phases of the reproductive cycle. PMID:22822422

  12. The ART of mating: alternative reproductive tactics and mating success in a nest-guarding fish.

    PubMed

    Mascolino, S; Benvenuto, C; Gubili, C; Sacchi, C; Boufana, B; Mariani, S

    2016-12-01

    Behavioural observations in the field of male Mediterranean damselfish Chromis chromis were combined with molecular analyses, using bi-parentally and maternally inherited markers, to investigate reproductive success patterns of alternative reproductive tactics (ARTs) in terms of number of eggs sired and number of females contributing to each nest. Cuckoldry was observed in every nest sampled, with at least two and up to seven sneaker males per nest. The nesting male, however, always significantly fertilized the greater number of eggs (on average 49%) in each clutch, whereas each sneaker fertilized around 7% of the clutch. The average number of females whose eggs were fertilized by nesting males was 6·76 (range 2-13), while each sneaker on average fertilized the eggs of 1·74 (range 1-8) females. Using this sibship reconstruction, some of the factors involved in the regulation of the dynamic equilibrium of reproductive success were investigated between the two ARTs shown by C. chromis males. Results show that the sneakers' reproductive success was positively linked to egg clutch size; the density of individuals in the nesting area negatively affected the size of egg clutches; the rate of defence behaviours performed by nesting males negatively influenced the number of females contributing to each nest.

  13. Styrene dimers and trimers affect reproduction of daphnid (Ceriodaphnia dubia).

    PubMed

    Tatarazako, Norihisa; Takao, Yuji; Kishi, Katsuyuki; Onikura, Norio a; Arizono, Koji; Iguchi, Taisen

    2002-08-01

    The endocrine disruptor activity of styrene in humans and other vertebrates appears to be negligible. However, offspring numbers were reduced in Ceriodaphnia dubia bred in polystyrene cups. Styrene dimers and trimers were found to be eluted from the polystyrene cups by hexane and methanol with gas chromatography-mass spectrometry. Styrene dimers and trimers at concentrations of 0.04-1.7 microg/l affected C. dubia fertility (25% reduction after seven days), suggesting that styrenes have the potential to impair crustacean populations in the aquatic environment.

  14. Exposure to Environmentally Relevant Concentrations of Genistein during Activation Does Not Affect Sperm Motility in the Fighting Fish Betta splendens

    PubMed Central

    Clotfelter, Ethan D.; Gendelman, Hannah K.

    2014-01-01

    Sperm collected from male fighting fish Betta splendens were activated in control water, water containing the ion-channel blocker gadolinium (a putative positive control), or water containing the isoflavone phytoestrogen genistein to determine the effects of acute genistein exposure on male reproductive function. Computer-assisted sperm analysis was used to quantify the proportion of sperm that were motile and the swimming velocity of those sperm. The highest concentration of gadolinium (100 μM) tested was effective at reducing sperm motility and velocity, but neither concentration of genistein tested (3.7 nM or 3.7 μM) significantly affected these sperm parameters. Our findings suggest that acute exposure to waterborne phytoestrogens during activation does not reduce the motility of fish sperm. PMID:24516856

  15. Exposure to environmentally relevant concentrations of genistein during activation does not affect sperm motility in the fighting fish Betta splendens.

    PubMed

    Clotfelter, Ethan D; Gendelman, Hannah K

    2014-01-01

    Sperm collected from male fighting fish Betta splendens were activated in control water, water containing the ion-channel blocker gadolinium (a putative positive control), or water containing the isoflavone phytoestrogen genistein to determine the effects of acute genistein exposure on male reproductive function. Computer-assisted sperm analysis was used to quantify the proportion of sperm that were motile and the swimming velocity of those sperm. The highest concentration of gadolinium (100 μ M) tested was effective at reducing sperm motility and velocity, but neither concentration of genistein tested (3.7 nM or 3.7 μ M) significantly affected these sperm parameters. Our findings suggest that acute exposure to waterborne phytoestrogens during activation does not reduce the motility of fish sperm.

  16. Social deprivation affects cooperative predator inspection in a cichlid fish

    PubMed Central

    Hesse, Saskia; Anaya-Rojas, Jaime M.; Frommen, Joachim G.; Thünken, Timo

    2015-01-01

    The social environment individuals are exposed to during ontogeny shapes social skills and social competence in group-living animals. Consequently, social deprivation has serious effects on behaviour and development in animals but little is known about its impact on cooperation. In this study, we examined the effect of social environment on cooperative predator inspection. Predator inspection behaviour is a complex behaviour, which is present in a variety of shoaling fish species. Often, two fish leave the safety of the group and inspect a potentially dangerous predator in order to gather information about the current predation risk. As predator inspection is highly risky, it is prone to conflicts and cheating. However, cooperation among individuals may reduce the individual predation risk. We investigated this complex social behaviour in juveniles of the cichlid fish Pelvicachromis taeniatus that were reared in two different social environments throughout development. Fish reared in a group inspected more often than isolation-reared fish and were more likely to cooperate, i.e. they conducted conjoint inspection of a predator. By contrast, isolation-reared fish were more likely to perform a single inspection without a companion. These results suggest an impairment of cooperative behaviour in isolation-reared fish most probably due to lack of social experience and resulting in lowered social skills needed in coordinated behaviour. PMID:26064616

  17. Reproductive impairment of a viviparous fish species inhabiting a freshwater system with anthropogenic impact.

    PubMed

    Hued, Andrea Cecilia; Nostro, Fabiana Laura Lo; Wunderlin, Daniel Alberto; Bistoni, María de Los Ángeles

    2013-02-01

    The potential threat to animal reproduction by contaminated freshwater systems posed the necessity to identify and develop bioindicators and biomarkers to be used for screening and evaluation of the effects in organisms. The main goal of this work was to determine, through histological analyses and changes in gonopodium morphology, whether a freshwater system polluted by anthropogenic activities-sewage, agricultural, and industrial-could cause alterations at the organ level. We also propose the live-bearing fish, Jenynsia multidentata, as a species suitable to study the effects of contaminated aquatic environments. We compared male fish sampled at two different stations in Suquía River basin (Córdoba, Argentina), both differing in degree of pollution, through liver and testis histology and gonopodial morphometric parameters. The water quality, based on the physicochemical characteristics of the studied stations, varied markedly with a decrease in water quality at the downstream site (station 2). At the highest polluted area, detrimental effects on liver and testis were evidenced on histological analysis. Male individuals from station 2 also presented noticeable structural changes of the anal fin, such as a straight gonopodium and abnormal tip area. The present results demonstrate that a freshwater system polluted by the impacts of anthropogenic activities has detrimental effects to J. multidentata. The alterations registered in individuals from the polluted station indicate an impairment of male reproductive performance and imply a risk for other live-bearing species as well as the entire biodiversity. We consider J. multidentata a sentinel species that is useful to evaluate the potential risk present in the studied basin not only to itself but to other species as well.

  18. REPRODUCTION AND AROMATASE ACTIVITY IN THE MARINE FISH CUNNER (TAUTOGOLABROUS ADSPERSUS) EXPOSED TO ATRAZINE AND OCTYLPHENOL IN THE LABORATORY

    EPA Science Inventory

    This study was conducted to test the hypothesis that reproduction in fish is altered by exposure to endocrine-disrupting chemicals (EDCs) that modify aromatase activity. Aromatase, a product of the CYP19 gene, is the enzyme that catalyzes the conversion of the androgens androst...

  19. How does fish metamorphosis affect aromatic amino acid metabolism?

    PubMed

    Pinto, Wilson; Figueira, Luís; Dinis, Maria Teresa; Aragão, Cláudia

    2009-02-01

    Aromatic amino acids (AAs, phenylalanine and tyrosine) may be specifically required during fish metamorphosis, since they are the precursors of thyroid hormones which regulate this process. This project attempted to evaluate aromatic AA metabolism during the ontogenesis of fish species with a marked (Senegalese sole; Solea senegalensis) and a less accentuated metamorphosis (gilthead seabream; Sparus aurata). Fish were tube-fed with three L-[U-14C] AA solutions at pre-metamorphic, metamorphic and post-metamorphic stages of development: controlled AA mixture (Mix), phenylalanine (Phe) and tyrosine (Tyr). Results showed a preferential aromatic AA retention during the metamorphosis of Senegalese sole, rather than in gilthead seabream. Senegalese sole's highly accentuated metamorphosis seems to increase aromatic AA physiological requirements, possibly for thyroid hormone production. Thus, Senegalese sole seems to be especially susceptible to dietary aromatic AA deficiencies during the metamorphosis period, and these findings may be important for physiologists, fish nutritionists and the flatfish aquaculture industry.

  20. Habitat characteristics affecting fish assemblages on a Hawaiian coral reef

    USGS Publications Warehouse

    Friedlander, A.M.; Parrish, J.D.

    1998-01-01

    Habitat characteristics of a reef were examined as potential influences on fish assemblage structure, using underwater visual census to estimate numbers and biomass of all fishes visible on 42 benthic transects and making quantitative measurements of 13 variables of the corresponding physical habitat and sessile biota. Fish assemblages in the diverse set of benthic habitats were grouped by detrended correspondence analysis, and associated with six major habitat types. Statistical differences were shown between a number of these habitat types for various ensemble variables of the fish assemblages. Overall, both for complete assemblages and for component major trophic and mobility guilds, these variables tended to have higher values where reef substratum was more structurally or topographically complex, and closer to reef edges. When study sites were separately divided into five depth strata, the deeper strata tended to have statistically higher values of ensemble variables for the fish assemblages. Patterns with depth varied among the various trophic and mobility guilds. Multiple linear regression models indicated that for the complete assemblages and for most trophic and mobility guilds, a large part of the variability for most ensemble variables was explained by measures of holes in the substratum, with important contributions from measured substratum rugosity and depth. A strong linear relationship found by regression of mean fish length on mean volume of holes in the reef surface emphasized the importance of shelter for fish assemblages. Results of this study may have practical applications in designing reserve areas as well as theoretical value in helping to explain the organization of reef fish assemblages.

  1. Kraft mill effluent survey: progress toward best management practices for reducing effects on fish reproduction.

    PubMed

    Kovacs, Tibor G; Martel, Pierre H; O'Connor, Brian I; Parrott, Joanne L; McMaster, Mark E; Van Der Kraak, Glen J; MacLatchy, Deborah L; van den Heuvel, Michael R; Hewitt, L Mark

    2011-06-01

    Pulp and paper mill effluents have been linked to effects on fish reproduction for more than 25 years. To date, the causes of these effects and remedial strategies have eluded investigators. Recent work has shown that the degree of reproductive effect caused by a mill effluent is related to the overall organic content. If verified, this could lead to breakthroughs for best management practices (BMPs). For this study, the effluents from seven kraft mills were assessed for their ability to reduce egg production in fathead minnow (Pimephales promelas) in the laboratory. At the same time, the effluents were analyzed for three parameters thought to be good indicators of organic losses: biochemical oxygen demand (BOD), methyl-substituted 2-cyclopentenones (cellulose degradation products), and a gas chromatographic (GC) profile index, which integrates the total area of the chromatographic peaks of solvent-extracted effluents using low-resolution mass spectrometry. The results showed that the degree to which the effluents reduced egg production increased with increased organic losses as characterized by BOD and the GC profile index. Therefore, these parameters could be used to guide BMPs at kraft mills according to specific targets: BOD < 20 mg/L and GC profile index equivalent to effluent with BOD of 20 mg/L. Such targets should be achievable by good in-plant control of organic losses and optimized effluent biotreatment systems.

  2. Identification of hemiclonal reproduction in three species of Hexagrammos marine reef fishes.

    PubMed

    Kimura-Kawaguchi, M R; Horita, M; Abe, S; Arai, K; Kawata, M; Munehara, H

    2014-08-01

    Natural hybrids between the boreal species Hexagrammos octogrammus and two temperate species Hexagrammos agrammus and Hexagrammos otakii were observed frequently in southern Hokkaido, Japan. Previous studies revealed that H. octogrammus is a maternal ancestor of both hybrids; the hybrids are all fertile females and they frequently breed with paternal species. Although such rampant hybridization occurs, species boundaries have been maintained in the hybrid zone. Possible explanations for the absence of introgressions, despite the frequent backcrossing, might include clonal reproduction: parthenogenesis, gynogenesis and hybridogenesis. The natural hybrids produced haploid eggs that contained only the H. octogrammus genome (maternal ancestor) with discarded paternal genome and generated F1 -hybrid type offspring by fertilization with the haploid sperm of H. agrammus or H. otakii (paternal ancestor). This reproductive mode was found in an artificial backcross hybrid between the natural hybrid and a male of the paternal ancestor. These findings indicate that the natural hybrids adopt hybridogenesis with high possibility and produce successive generations through hybridogenesis by backcrossing with the paternal ancestor. These hybrids of Hexagrammos represent the first hybridogenetic system found from marine fishes that widely inhabit the North Pacific Ocean. In contrast with other hybridogenetic systems, these Hexagrammos hybrids coexist with all three ancestral species in the hybrid zone. The coexistence mechanism is also discussed.

  3. The Relationship between Organic Loading and Effects on Fish Reproduction for Pulp Mill Effluents across Canada.

    PubMed

    Martel, Pierre H; O'Connor, Brian I; Kovacs, Tibor G; van den Heuvel, Michael R; Parrott, Joanne L; McMaster, Mark E; MacLatchy, Deborah L; Van Der Kraak, Glen J; Hewitt, L Mark

    2017-03-09

    This study builds upon the work of a multiagency consortium tasked with determining cost-effective solutions for the effects of pulp mill effluents on fish reproduction. A laboratory fathead minnow egg production test and chemical characterization tools were used to benchmark 81 effluents from 20 mills across Canada, representing the major pulping, bleaching, and effluent treatment technologies. For Kraft and mechanical pulp mills, effluents containing less than 20 mg/L BOD5 were found to have the greatest probability of having no effects. Organic loading, expressed as the total detected solvent-extractable components by gas chromatography/mass spectrometry (GC/MS), also correlated with decreased egg laying. Exceptions were found for specific Kraft, mechanical, and sulfite mills, suggesting yet unidentified causative agents are involved. Recycled fiber mill effluents, tested for the first time, were found to have little potential for reproductive effects despite large variations in BOD5 and GC/MS profiles. Effluent treatment systems across all production types were generally efficient, achieving a combined 82-98% BOD5 removal. Further reductions of final effluent organic loadings toward the target of less than 20 mg/L are recommended and can be realized through biotreatment optimization, the reduction of organic losses associated with production upsets and selecting best available technologies that reduce organic loadings to biotreatment.

  4. Factors affecting the reproductive success of American Oystercatchers Haematopus palliatus on the outer banks of North Carolina

    USGS Publications Warehouse

    Schulte, Shiloh A.; Simons, Theodore R.

    2015-01-01

    We used an information-theoretic approach to assess the factors affecting the reproductive success of American Oystercatchers Haematopus palliatus on the Outer Banks of North Carolina. We evaluated survival with respect to nesting island, year, time of season, brood age, distance to tide (m), presence of off-road vehicles and proximity of foraging habitat. The daily nest survival (mean 0.981, standard error [SE] 0.002) was affected by year and island, and declined over the nesting season. Mammals were responsible for 54% of identified nest failures. Daily brood survival (mean 0.981, SE 0.002) varied by island and increased non-linearly with age, with highest mortality in the seven days after hatching. Model results indicate direct access to foraging sites has a positive effect on brood survival, whereas presence of off-road vehicles has a negative effect. We studied chick behavior and survival using radio telemetry and direct observation and found that vehicles caused mortality and affected behavior and resource use by oystercatcher chicks. We identified the source of mortality for 37 radio-tagged chicks. Six (16%) were killed by vehicles, 21 (57%) by predators, and 10 (27%) by exposure and starvation. From 1995 to 2008, 25 additional oystercatcher chicks were found dead, 13 (52%) killed by vehicles. Chicks on beaches closed to vehicles used beach and intertidal zones more frequently than chicks on beaches open to vehicles. Chick predators included Great Horned Owls Bubo virginianus, Fish Crows Corvus ossifragus, cats Felis catus, mink Mustela vison, raccoons Procyon lotor, and ghost crabs Ocypode albicans. The factors affecting reproductive success differed between the incubation and chick-rearing stages.  Management actions that influence chick survival will have a larger effect on total productivity than actions affecting nest survival.

  5. Effect of commercial grade endosulfan on growth and reproduction of the fighting fish Betta splendens.

    PubMed

    Balasubramani, A; Pandian, T J

    2014-09-01

    To study the effects of endosulfan on survival, growth and reproduction of the obligate air-breathing male heterogametic fighting fish Betta splendens, posthatchlings of the fighting fish were discretely immersed for 3 h/day during the labile period on the 2nd, 5th, and 8th day posthatching (dph) at selected concentrations of commercial grade endosulfan ranging from 175 to 1400 ng/L. The immersions at 1,400 ng/L led to 21% mortality, among the 79% of surviving fry, 80% developed into females. The endosulfan reduced the air-breathing frequency of 5- and 8-day old hatchlings, and the reduction in the frequency persisted even after a depuration period of 172 days. In the ovary of the treated females, reduced number of vitellogenic oocytes with increased vacuolar cavities was observed. In the testis of the treated males, the reduced number of spermatogonia with increased vacuolar cavities was observed. The treated male induced the female to spawn a fewer eggs, which were subsequently incubated in his smaller bubble nest. The control females attained puberty on the 138th dph and spawned 120 eggs once in every 15 days, the females, which were previously treated at 1400 ng/L, postponed puberty to the 179th dph and spawned 70 eggs once in every 32 days. During the 240-day experiment, endosulfan is found to reduce significantly the cumulative progeny production from 760 to 144, reducing significantly to 19% of the control.

  6. A test of male infanticide as a reproductive tactic in a cichlid fish

    PubMed Central

    Bose, Aneesh P. H.; O'Connor, Constance M.; Balshine, Sigal

    2017-01-01

    Infanticide and offspring cannibalism are taxonomically widespread phenomena. In some group-living species, a new dominant individual taking over a group can benefit from infanticide if doing so induces potential mates to become reproductively available sooner. Despite widespread observations of infanticide (i.e. egg cannibalism) among fishes, no study has investigated whether egg cannibalism occurs in fishes as a result of group takeovers, or how this type of cannibalism might be adaptive. Using the cooperatively breeding cichlid, Neolamprologus pulcher, we tested whether new unrelated males entering the dominant position in a social group were more likely to cannibalize eggs, and whether such cannibalism would shorten the interval until the female's next spawning. Females spawned again sooner if their broods were removed than if they were cared for. Egg cannibalism occurred frequently after a group takeover event, and was rarer if the original male remained with the group. While dominant breeder females were initially highly aggressive towards newcomer males that took over the group, the degree of resistance depended on relative body size differences between the new pair and, ultimately, female aggression did not prevent egg cannibalism. Egg cannibalism, however, did not shorten the duration until subsequent spawning, or increase fecundity during subsequent breeding in our laboratory setting. Our results show that infanticide as mediated through group takeovers is a taxonomically widespread behaviour.

  7. Microcystin-LR impairs zebrafish reproduction by affecting oogenesis and endocrine system.

    PubMed

    Zhao, Yanyan; Xie, Liqiang; Yan, Yunjun

    2015-02-01

    Previous studies have shown that microcystins (MCs) are able to exert negative effects on the reproductive system of fish. However, few data are actually available on the effects of MC-LR on the reproductive system of female fish. In the present study, female zebrafish were exposed to 2, 10, and 50 μg L(-1) of MC-LR for 21 d, and its effects on oogenesis, sex hormones, transcription of genes on the hypothalamic-pituitary-gonad (HPG) axis, and reproduction were investigated for the first time. It was observed that egg production significantly declined at ⩾ 10 μg L(-1) MC-LR. MC-LR exposure to zebrafish increased the concentrations of 17β-estradiol (E2) and vitellogenin (VTG) at 10 μg L(-1) level, whereas concentrations of E2, VTG and testosterone declined at 50 μg L(-1) MC-LR. The transcriptions of steroidogenic pathway gene (cyp19a, cyp19b, 17βhsd, cyp17 and hmgra) changed as well after the exposure and corresponded well with the alterations of hormone levels. A number of intra- and extra-ovarian factors, such as gnrh3, gnrhr1, fshβ, fshr, lhr, bmp15, mrpβ, ptgs2 and vtg1 which regulate oogenesis, were significantly changed with a different dose-related effect. Moreover, MC-LR exposure to female zebrafish resulted in decreased fertilization and hatching rates, and may suggest the possibility of trans-generational effects of MC-LR exposure. The results demonstrate that MC-LR could modulate endocrine function and oogenesis, eventually leading to disruption of reproductive performance in female zebrafish. These data suggest there is a risk for aquatic population living in MC polluted areas.

  8. Mink reproductive and physiological response to diets supplemented with PCB and mercury contaminated fish collected on the Oak Ridge Reservation

    SciTech Connect

    Halbrook, R.; Aulerich, R.; Bursian, S.; Lewis, L.

    1995-12-31

    Plant operations and waste disposal at the Department of Energy Oak Ridge Reservation (ORR) have resulted in increased concentrations of PCBs and mercury (Hg) in fish inhabiting streams located on the reservation. As a component of environmental restoration investigation, fish were collected from streams on the reservation, analyzed for tissue concentrations of PCBs and Hg, and fed to ranch mink 3 months prior to and during the breeding season. As reference, fish also were collected from the Clinch River (CR) above the ORR and from the ocean (O), and fed to mink following similar procedures. Five prepared diets containing either 75% O, 75% CR, 25% ORR + 50% O, 50% ORR + 25% O, or 75% ORR fish and 25% standard mink diet were fed to 8 female and 2 male mink, each, following normal mink farm practices. PCB (Aroclor 1260 and CB congeners) and Hg concentrations were greatest in fish collected from the ORR and diets containing ORR fish exhibited a progressive increase in PCBs and Hg concentration with increased percentage of ORR fish. Female mink fed diets containing 75% ORR fish had decreased litter size and decreased mean whole body weights, Mean weight of male offspring of females fed 75% ORR fish also were decreased. Do to the contaminated environment, other aquatic prey of mink probably have elevated contaminant burdens that would contribute to effects in mink. Adverse reproductive and health effects in mink living on the ORR are speculative at this time.

  9. Population structure and reproductive period of two introduced fish species in a Brazilian semiarid region reservoir.

    PubMed

    Sousa, Marla Melise de Oliveira; Lopes, Suzany Iasnaya Moreira; da Costa, Rodrigo Silva; Novaes, José Luís Costa

    2015-09-01

    The Amazonian fish species Plagioscion squamosissimus (Sciaenidae) and Cichla monoculus Cichlidae), have been widely introduced into different reservoirs in Brazil, and have caused many negative mpacts on local fish fauna. The aim of this study was to evaluate the population structure (abundance, length structure, length-weight relationship, sex ratio, and length at first maturity) and the reprodutive period of these wo species in the Santa Cruz Reservoir (built in 2002), located in the Brazilian semiarid region, for their adequate management and local species conservation policies. Specimens were collected quarterly in eight sites from February 2010 to November 2013 using gillnets (12 to 70 mm mesh between adjacent knots). The specimens captured were counted and the following biometric and biological data were analysed: standard length, total weight, and reproductive data, such as, sex, weight and gonadal maturity stage. The species abundances were estimated by CPUE and expressed as the number of individuals per gill net area x gill net exposition time (m2 x h); length frequency histograms were built with intervals of 5 cm. The length-weight parameters were estimated with a linear regression after a logarithmic transformation of the data. With the reproductive data we estimated sex ratio, reproduction period and length at first maturity (L50). We captured a total of 1,071 specimens of P. squamosissimus and 156 specimens of C. monoculus. Both species showed higher abundances in 2010, 0.004306 m2 x h and 0.00022 m2 x h, respectively, but this parameter decreased from 2010 to 2013. Standard length ranged between 6.4 and 46.2 cm for P. squamosissimus (20.025.0 cm was the most frequent class), and 7.0 and 38.7 cm for C. monocidus (10.0-15.0 cm was the most frequent class). The length-weight relationships were described by the following equations: log10Wt = -1.8349+3.0899log10Lp and R2= 0.9795 for P. squamosissimus, and log10 Wt = -1.7944+3.0885log10Lp and Wt = 0

  10. Effects of Two Endocrine-active Pharmaceuticals, Tamoxifen and Anastrozole, on Reproduction in a Marine Fish, Tautogolabrus adspersus

    EPA Science Inventory

    Endocrine-active pharmaceuticals entering the aquatic environment through sewage effluent may have unintended, adverse impacts on the reproduction of aquatic organisms, which in turn may affect the sustainability of exposed populations. Laboratory experiments were conducted with ...

  11. Predation and landscape characteristics independently affect reef fish community organization.

    PubMed

    Stier, Adrian C; Hanson, Katharine M; Holbrook, Sally J; Schmitt, Russell J; Brooks, Andrew J

    2014-05-01

    Trophic island biogeography theory predicts that the effects of predators on prey diversity are context dependent in heterogeneous landscapes. Specifically, models predict that the positive effect of habitat area on prey diversity should decline in the presence of predators, and that predators should modify the partitioning of alpha and beta diversity across patchy landscapes. However, experimental tests of the predicted context dependency in top-down control remain limited. Using a factorial field experiment we quantify the effects of a focal predatory fish species (grouper) and habitat characteristics (patch size, fragmentation) on the partitioning of diversity and assembly of coral reef fish communities. We found independent effects of groupers and patch characteristics on prey communities. Groupers reduced prey abundance by 50% and gamma diversity by 45%, with a disproportionate removal of rare species relative to common species (64% and 36% reduction, respectively; an oddity effect). Further, there was a 77% reduction in beta diversity. Null model analysis demonstrated that groupers increased the importance of stochastic community assembly relative to patches without groupers. With regard to patch size, larger patches contained more fishes, but a doubling of patch size led to a modest (36%) increase in prey abundance. Patch size had no effect on prey diversity; however, fragmented patches had 50% higher species richness and modified species composition relative to unfragmented patches. Our findings suggest two different pathways (i.e., habitat or predator shifts) by which natural and/or anthropogenic processes can drive variation in fish biodiversity and community assembly.

  12. Risk of predation reflects variation in the reproductive strategy of a dominant forage fish in mangrove tidal tributaries.

    PubMed

    Krebs, Justin M; Bell, Susan S

    2012-03-01

    The role of predators in shaping prey life histories is a central theme in the ecological literature. However, the association between degree of predation risk and prey reproductive strategies has not been clearly established. We examined reproduction in the sailfin molly (Poecilia latipinna) from small tidal tributaries in a subtropical estuary. Our results revealed a gradient along which females produced many, small offspring at one extreme (mean = 42 offspring, 17 mg each) and fewer, larger offspring at the other (24 offspring, 29 mg each). Reproductive allotment ranged from 14.9-21.5% of maternal biomass. Based on our observation of divergent reproductive strategies, we experimentally tested the null hypothesis of no difference in predation risk among tributaries using a novel quantitative approach to estimate predation. We predicted greater risk in tributaries where mollies produced many, small offspring. Tethering confirmed increasing risk from 16.2 ± 5.3% SE to 54.7 ± 3.6% fish lost h(-1) across sites in agreement with observed variation in reproduction. Predation was unexpectedly higher than predicted at one of the four sites suggesting that additional factors (e.g., food) had influenced reproduction there. Our results provide insight into the well-studied concept of predator-mediated variation in prey reproduction by quantitatively demonstrating differential risk for mollies exhibiting divergent reproductive strategies. While the observed range of variation in reproductive traits was consistent with previous studies reporting strong predator effects, higher than expected predation in one case may suggest that the prey response does not follow a continuous trajectory of incremental change with increasing predation risk, but may be better defined as a threshold beyond which a significant shift in reproductive strategy occurs.

  13. Reproductive periodicity and steroid hormone profiles in the sex-changing coral-reef fish, Plectropomus leopardus

    NASA Astrophysics Data System (ADS)

    Frisch, A. J.; McCormick, M. I.; Pankhurst, N. W.

    2007-03-01

    The reproductive biology of coral trout, Plectropomus leopardus, from the Great Barrier Reef (Australia) was investigated by correlating gonadal condition with plasma levels of gonadal steroids. Female fish were found to be regressed from mid-summer to early spring, after which rapid and cyclical increases in gonado-somatic index ( I G), maximum oocyte diameter (MOD) and plasma concentrations of estradiol-17β and testosterone were detected. Male fish, in contrast, commenced recrudescence slightly earlier in winter and responded with less dramatic increases in both I G and plasma concentrations of testosterone and 11-ketotestosterone. The mode of oocyte development was multiple group-synchronous, and cyclical fluctuations in reproductive parameters ( I G, MOD and gonadal steroid concentrations) were synchronized with new-moon lunar phases. It is likely, therefore, that individual P. leopardus have the capacity to spawn on multiple occasions, with lunar periodicity. However, evidence suggests that early bouts of reproduction may be more important in terms of reproductive investment than subsequent bouts later in the same season. It is concluded that patterns of gametogenesis and steroidogenesis in P. leopardus are similar to the patterns displayed by other tropical groupers, suggesting that management regimes and propagation protocols developed for these fishes may also be appropriate for use with P. leopardus.

  14. Comparative morphology of the reproductive system of seven species of ostariophysan fishes from the upper Das Velhas River, Brazil.

    PubMed

    Melo, Rafael Magno Costa; Gomes, Débora Diniz; Moreira, Davidson Peruci; Gomes, Maysa Regina; Bazzoli, Nilo; Rizzo, Elizete

    2017-02-01

    The success of fishes in different environments is related with the variation of reproductive strategies developed by the systematic group, which is reflected in the morphology of the reproductive system and can have ecological and evolutionary implications. This study comparatively analyzed the morphological characteristics of the male and female reproductive systems of ostariophysan fish species from the upper Das Velhas River in the São Francisco River basin, Brazil. In order to accomplish this, 393 specimens belonging to seven fish species were sampled between April 2010 and June 2015 for histological, ultrastructural, histochemical, and morphometric analyses. All the species examined have anastomosing tubular testes with unrestricted distribution of spermatogonia. Astyanax bimaculatus, A. fasciatus, A. scabripinnis, and Harttia torrenticola had their spermatozoa embedded in a glycoprotein secretion within the tubule lumen. Most species had type I spermiogenesis, whereas Rhamdia quelen had type III spermiogenesis. While all females examined had asynchronous oocyte development, there were remarkable morphological, histochemical, and morphometric differences in the ovarian follicles and enveloping layers. Hoplias malabaricus and H. torrenticola, which exhibit parental care behaviour, had a significantly larger diameter of vitellogenic oocytes and larger spermatozoa nuclei. Apareiodon ibitiensis, H. torrenticola, and A. scabripinnis, species that have rheophilic preferences, exhibited a thicker zona radiata than the other species examined. The follicular cells of R. quelen and H. torrenticola were columnar and produced a jelly coat and mucosubstances, respectively. The females of the seven fish species studied show a correlation of the reproductive strategies with the reproductive system morphology, while males retained more similar morphological characteristics between species. J. Morphol. 278:170-181, 2017. © 2016 Wiley Periodicals,Inc.

  15. Reproductive biology and recruitment of the deep-sea fish community from the NW Mediterranean continental margin

    NASA Astrophysics Data System (ADS)

    Fernandez-Arcaya, U.; Rotllant, G.; Ramirez-Llodra, E.; Recasens, L.; Aguzzi, J.; Flexas, M. M.; Sanchez-Vidal, A.; López-Fernández, P.; García, J. A.; Company, J. B.

    2013-11-01

    Temporal patterns in deep-sea fish reproduction are presently unknown for the majority of deep continental margins. A series of seasonal trawling surveys between depths of 300 to 1750 m in the Blanes submarine canyon and its adjacent open slope (NW Mediterranean) were conducted. The bathymetric size distributions and reproductive cycles of the most abundant species along the NW Mediterranean margin were analyzed to assess the occurrence of (i) temporal patterns in reproduction (i.e., spawning season) along a bathymetric gradient and (ii) preferential depth strata for recruitment. The fish assemblages were grouped in relation to their bathymetric distribution: upper slope, middle slope and lower slope species. Middle-slope species (i.e., 800-1350 m) showed short (i.e., highly seasonal) reproductive activity compared to the upper (300-800 m) and lower (1350-1750 m) ones. Our results, together with those previously published for megabenthic crustacean decapods in the area, suggest a cross-phyla depth-related trend of seasonality in reproduction. In the middle and lower slope species, the reproductive activity reached a maximum in the autumn-winter months and decreased in the spring. The observed seasonal spawning patterns appear to be ultimately correlated with changes in the downward transport of organic particles and with seasonal changes in the physicochemical characteristics of the surrounding water masses. The distribution of juveniles was associated with the bathymetric stratum where intermediate nepheloid layers interact with the continental margins, indicating that this stratum acts as a deep-sea fish nursery area.

  16. Effect on growth and reproduction of hormone immersed and masculinized fighting fish Betta splendens.

    PubMed

    Kirankumar, Santhakumar; Pandian, Thavamani Jegajothivel

    2002-11-01

    To produce all-male progenies in the fighting fish, Betta splendens, six groups of fry were subjected to discrete immersion treatment at different 17alpha-methyltestosterone (MT) doses (viz. 100, 200, 500, 700, 900, and 1,000 microg/l) for a constant duration (3 hr/day) and frequency (second, fifth, and eighth day after hatching). The treatment at 900 microg/l led to 98% masculinization and 71% survival at sexual maturity. Treated groups, which showed significant deviation from the 1:1 sex ratio, were classified into two different series: S1 and S2. The groups that showed nearly cent-percent masculinization were classified as S1, and the other groups were classified as S2. The S1 males showed remarkably slower growth and attained 3.5 cm total length compared to 6.0 cm attained by a normal male. The S2 males attained 5.4 cm total length. Apart from these morphological defects, both S1 and S2 males suffered functional (decreased sperm count and sperm motility) and behavioral defects (incomplete embracing during mating) in their reproductive ability, leading to approximately 50% and 30% reduction in fecundity per mating, respectively. The cumulative fecundity loss suffered by the S1 male during its active reproductive phase is discussed. When normal and sex-reversed males were presented, a female preferred the former. Progeny testing of the sex-reversed males showed the occurrence of 12.75% males, indicating the possible role of autosomal genes in the sex determination mechanism of this species. Discrete immersion treatment at optimal/super-optimal doses ensured not only a higher percentage of masculinization, but also a higher frequency of homogametic males (XX).

  17. Male seminal fluid substances affect sperm competition success and female reproductive behavior in a seed beetle.

    PubMed

    Yamane, Takashi; Goenaga, Julieta; Rönn, Johanna Liljestrand; Arnqvist, Göran

    2015-01-01

    Male seminal fluid proteins are known to affect female reproductive behavior and physiology by reducing mating receptivity and by increasing egg production rates. Such substances are also though to increase the competitive fertilization success of males, but the empirical foundation for this tenet is restricted. Here, we examined the effects of injections of size-fractioned protein extracts from male reproductive organs on both male competitive fertilization success (i.e., P2 in double mating experiments) and female reproduction in the seed beetle Callosobruchus maculatus. We found that extracts of male seminal vesicles and ejaculatory ducts increased competitive fertilization success when males mated with females 1 day after the females' initial mating, while extracts from accessory glands and testes increased competitive fertilization success when males mated with females 2 days after the females' initial mating. Moreover, different size fractions of seminal fluid proteins had distinct and partly antagonistic effects on male competitive fertilization success. Collectively, our experiments show that several different seminal fluid proteins, deriving from different parts in the male reproductive tract and of different molecular weight, affect male competitive fertilization success in C. maculatus. Our results highlight the diverse effects of seminal fluid proteins and show that the function of such proteins can be contingent upon female mating status. We also document effects of different size fractions on female mating receptivity and egg laying rates, which can serve as a basis for future efforts to identify the molecular identity of seminal fluid proteins and their function in this model species.

  18. Male Seminal Fluid Substances Affect Sperm Competition Success and Female Reproductive Behavior in a Seed Beetle

    PubMed Central

    Yamane, Takashi; Goenaga, Julieta; Rönn, Johanna Liljestrand; Arnqvist, Göran

    2015-01-01

    Male seminal fluid proteins are known to affect female reproductive behavior and physiology by reducing mating receptivity and by increasing egg production rates. Such substances are also though to increase the competitive fertilization success of males, but the empirical foundation for this tenet is restricted. Here, we examined the effects of injections of size-fractioned protein extracts from male reproductive organs on both male competitive fertilization success (i.e., P2 in double mating experiments) and female reproduction in the seed beetle Callosobruchus maculatus. We found that extracts of male seminal vesicles and ejaculatory ducts increased competitive fertilization success when males mated with females 1 day after the females’ initial mating, while extracts from accessory glands and testes increased competitive fertilization success when males mated with females 2 days after the females’ initial mating. Moreover, different size fractions of seminal fluid proteins had distinct and partly antagonistic effects on male competitive fertilization success. Collectively, our experiments show that several different seminal fluid proteins, deriving from different parts in the male reproductive tract and of different molecular weight, affect male competitive fertilization success in C. maculatus. Our results highlight the diverse effects of seminal fluid proteins and show that the function of such proteins can be contingent upon female mating status. We also document effects of different size fractions on female mating receptivity and egg laying rates, which can serve as a basis for future efforts to identify the molecular identity of seminal fluid proteins and their function in this model species. PMID:25893888

  19. Identification of Sex and Female's Reproductive Stage in Commercial Fish Species through the Quantification of Ribosomal Transcripts in Gonads.

    PubMed

    Rojo-Bartolomé, Iratxe; Diaz de Cerio, Oihane; Diez, Guzman; Cancio, Ibon

    2016-01-01

    The estimation of maturity and sex of fish stocks in European waters is a requirement of the EU Data Collection Framework as part of the policy to improve fisheries management. On the other hand, research on fish biology is increasingly focused in molecular approaches, researchers needing correct identification of fish sex and reproductive stage without necessarily having in house the histological know-how necessary for the task. Taking advantage of the differential gene transcription occurring during fish sex differentiation and gametogenesis, the utility of 5S ribosomal RNA (5S rRNA) and General transcription factor IIIA (gtf3a) in the molecular identification of sex and gametogenic stage was tested in different economically-relevant fish species from the Bay of Biscay. Gonads of 9 fish species (, Atlantic, Atlantic-chub and horse mackerel, blue whiting, bogue, European anchovy, hake and pilchard and megrim), collected from local commercial fishing vessels were histologically sexed and 5S and 18S rRNA concentrations were quantified by capillary electrophoresis to calculate a 5S/18S rRNA index. Degenerate primers permitted cloning and sequencing of gtf3a fragments in 7 of the studied species. 5S rRNA and gtf3a transcript levels, together with 5S/18S rRNA index, distinguished clearly ovaries from testis in all of the studied species. The values were always higher in females than in males. 5S/18S rRNA index values in females were always highest when fish were captured in early phases of ovary development whilst, in later vitellogenic stages, the values decreased significantly. In megrim and European anchovy, where gonads in different oogenesis stages were obtained, the 5S/18S rRNA index identified clearly gametogenic stage. This approach, to the sexing and the quantitative non-subjective identification of the maturity stage of female fish, could have multiple applications in the study of fish stock dynamics, fish reproduction and fecundity and fish biology in

  20. Food availability during migratory stopover affects testis growth and reproductive behaviour in a migratory passerine.

    PubMed

    Bauchinger, Ulf; Van't Hof, Thomas; Biebach, Herbert

    2009-03-01

    Long-distance migratory passerines initiate testicular recrudescence during spring migration to meet the demands of timely reproduction upon immediate arrival on the breeding grounds. The degree of testicular development is known to depend on environmental factors like stopover habitat quality; reproductive performance may be strongly impacted by testicular maturation upon arrival on the breeding grounds. We investigated the effect of stopover food availability on subsequent reproductive performance in garden warblers (Sylvia borin). Spring migration was simulated by repeated food deprivation and re-feeding to imitate the alternation of flight and stopover periods. During the two final stopover periods, males were either kept under ad libitum food (ad libitum males) or under limited food conditions (limited males). After simulated arrival in the breeding area, manipulation of previous stopover food availability resulted in significantly slower testicular recrudescence (p<0.001) and decreased plasma testosterone (p<0.01) in limited males compared to ad libitum males. Body mass change was not significantly different between the two groups (p=0.38). Limited males also exhibited reduced performance in reproductive behaviours employed in territorial and sexual contexts. Limited males had a longer 'freezing' interval (p<0.05) and decreased activity (p<0.01) when challenged with a live male decoy. In direct confrontation between limited and ad libitum males in the presence of a female, limited males exhibited significantly fewer behavioural traits in sexual context, i.e. directed to the female (p<0.001). Therefore, we suggest that conditions encountered during previous migratory stopover may affect subsequent annual reproductive success by influencing key reproductive behaviours.

  1. The African cichlid fish Astatotilapia burtoni uses acoustic communication for reproduction: sound production, hearing, and behavioral significance.

    PubMed

    Maruska, Karen P; Ung, Uyhun S; Fernald, Russell D

    2012-01-01

    Sexual reproduction in all animals depends on effective communication between signalers and receivers. Many fish species, especially the African cichlids, are well known for their bright coloration and the importance of visual signaling during courtship and mate choice, but little is known about what role acoustic communication plays during mating and how it contributes to sexual selection in this phenotypically diverse group of vertebrates. Here we examined acoustic communication during reproduction in the social cichlid fish, Astatotilapia burtoni. We characterized the sounds and associated behaviors produced by dominant males during courtship, tested for differences in hearing ability associated with female reproductive state and male social status, and then tested the hypothesis that female mate preference is influenced by male sound production. We show that dominant males produce intentional courtship sounds in close proximity to females, and that sounds are spectrally similar to their hearing abilities. Females were 2-5-fold more sensitive to low frequency sounds in the spectral range of male courtship sounds when they were sexually-receptive compared to during the mouthbrooding parental phase. Hearing thresholds were also negatively correlated with circulating sex-steroid levels in females but positively correlated in males, suggesting a potential role for steroids in reproductive-state auditory plasticity. Behavioral experiments showed that receptive females preferred to affiliate with males that were associated with playback of courtship sounds compared to noise controls, indicating that acoustic information is likely important for female mate choice. These data show for the first time in a Tanganyikan cichlid that acoustic communication is important during reproduction as part of a multimodal signaling repertoire, and that perception of auditory information changes depending on the animal's internal physiological state. Our results highlight the

  2. Chitosan-nanoconjugated hormone nanoparticles for sustained surge of gonadotropins and enhanced reproductive output in female fish.

    PubMed

    Rather, Mohd Ashraf; Sharma, Rupam; Gupta, Subodh; Ferosekhan, S; Ramya, V L; Jadhao, Sanjay B

    2013-01-01

    A controlled release delivery system helps to overcome the problem of short life of the leutinizing hormone releasing hormone (LHRH) in blood and avoids use of multiple injections to enhance reproductive efficacy. Chitosan- and chitosan-gold nanoconjugates of salmon LHRH of desired size, dispersity and zeta potential were synthesized and evaluated at half the dose rate against full dose of bare LHRH for their reproductive efficacy in the female fish, Cyprinus carpio. Whereas injections of both the nanoconjugates induced controlled and sustained surge of the hormones with peak (P<0.01) at 24 hrs, surge due to bare LHRH reached its peak at 7 hrs and either remained at plateau or sharply declined thereafter. While the percentage of relative total eggs produced by fish were 130 and 67 per cent higher, that of fertilised eggs were 171 and 88 per cent higher on chitosan- and chitosan-gold nanoconjugates than bare LHRH. Chitosan nanoconjugates had a 13 per cent higher and chitosan gold preparation had a 9 per cent higher fertilization rate than bare LHRH. Histology of the ovaries also attested the pronounced effect of nanoparticles on reproductive output. This is the first report on use of chitosan-conjugated nanodelivery of gonadotropic hormone in fish.

  3. Reproductive health policy affecting low-income women: historical precedents and current need for social work action.

    PubMed

    Averitt Taylor, Jessica

    2014-01-01

    This article provides an overview of the historical arguments surrounding reproductive health policy and current policy initiatives. Because reproductive policy itself is a vast subject matter with sometimes blurry boundaries, the struggle concerning the advent of birth control is used to illustrate the historic complexities of policy affecting such a wide array of individuals. The battle over introduction of the birth control pill is pertinent because the very same arguments are used today in debates over reproductive health policy.

  4. Chemical contaminants, health indicators, and reproductive biomarker responses in fish from the Colorado River and its tributaries

    USGS Publications Warehouse

    Hinck, J.E.; Blazer, V.S.; Denslow, N.D.; Echols, K.R.; Gross, T.S.; May, T.W.; Anderson, P.J.; Coyle, J.J.; Tillitt, D.E.

    2007-01-01

    Common carp (Cyprinus carpio), black bass (Micropterus spp.), and channel catfish (Ictalurus punctatus) were collected from 14 sites in the Colorado River Basin (CRB) to document spatial trends in accumulative contaminants, health indicators, and reproductive biomarkers. Organochlorine residues, 2,3,7,8-tetrachlorodibenzo-p-dioxin-like activity (TCDD-EQ), and elemental contaminants were measured in composite samples of whole fish, grouped by species and gender, from each site. Selenium (Se) and mercury (Hg) concentrations in fish were elevated throughout the CRB, and pesticide concentrations were greatest in fish from agricultural areas in the Lower Colorado River and Gila River. Selenium concentrations exceeded toxicity thresholds for fish (> 1.0????g/g ww) at all CRB sites except the Gila River at Hayden, Arizona. Mercury concentrations were elevated (> 0.1????g/g ww) in fish from the Yampa River at Lay, Colorado; the Green River at Ouray National Wildlife Refuge (NWR), Utah and San Rafael, Utah; the San Juan River at Hogback Diversion, New Mexico; and the Colorado River at Gold Bar Canyon, Utah, Needles, California, and Imperial Dam, Arizona. Concentrations of p,p???-DDE were relatively high in fish from the Gila River at Arlington, Arizona (> 1.0????g/g ww) and Phoenix, Arizona (> 0.5????g/g ww). Concentrations of other formerly used pesticides including toxaphene, total chlordanes, and dieldrin were also greatest at these two sites but did not exceed toxicity thresholds. Currently used pesticides such as Dacthal, endosulfan, ??-HCH, and methoxychlor were also greatest in fish from the Gila River downstream of Phoenix. Total polychlorinated biphenyls (PCBs; > 0.11????g/g ww) and TCDD-EQs (> 5??pg/g ww) exceeded wildlife guidelines in fish from the Gila River at Phoenix. Hepatic ethoxyresorufin O-deethylase (EROD) activity was also relatively high in carp from the Gila River at Phoenix and in bass from the Green River at Ouray NWR. Fish from some sites showed

  5. Chemical contaminants, health indicators, and reproductive biomarker responses in fish from the Colorado River and its tributaries.

    PubMed

    Hinck, Jo Ellen; Blazer, Vicki S; Denslow, Nancy D; Echols, Kathy R; Gross, Timothy S; May, Tom W; Anderson, Patrick J; Coyle, James J; Tillitt, Donald E

    2007-06-01

    Common carp (Cyprinus carpio), black bass (Micropterus spp.), and channel catfish (Ictalurus punctatus) were collected from 14 sites in the Colorado River Basin (CRB) to document spatial trends in accumulative contaminants, health indicators, and reproductive biomarkers. Organochlorine residues, 2,3,7,8-tetrachlorodibenzo-p-dioxin-like activity (TCDD-EQ), and elemental contaminants were measured in composite samples of whole fish, grouped by species and gender, from each site. Selenium (Se) and mercury (Hg) concentrations in fish were elevated throughout the CRB, and pesticide concentrations were greatest in fish from agricultural areas in the Lower Colorado River and Gila River. Selenium concentrations exceeded toxicity thresholds for fish (>1.0 microg/g ww) at all CRB sites except the Gila River at Hayden, Arizona. Mercury concentrations were elevated (>0.1 microg/g ww) in fish from the Yampa River at Lay, Colorado; the Green River at Ouray National Wildlife Refuge (NWR), Utah and San Rafael, Utah; the San Juan River at Hogback Diversion, New Mexico; and the Colorado River at Gold Bar Canyon, Utah, Needles, California, and Imperial Dam, Arizona. Concentrations of p,p'-DDE were relatively high in fish from the Gila River at Arlington, Arizona (>1.0 microg/g ww) and Phoenix, Arizona (>0.5 microg/g ww). Concentrations of other formerly used pesticides including toxaphene, total chlordanes, and dieldrin were also greatest at these two sites but did not exceed toxicity thresholds. Currently used pesticides such as Dacthal, endosulfan, gamma-HCH, and methoxychlor were also greatest in fish from the Gila River downstream of Phoenix. Total polychlorinated biphenyls (PCBs; >0.11 microg/g ww) and TCDD-EQs (>5 pg/g ww) exceeded wildlife guidelines in fish from the Gila River at Phoenix. Hepatic ethoxyresorufin O-deethylase (EROD) activity was also relatively high in carp from the Gila River at Phoenix and in bass from the Green River at Ouray NWR. Fish from some sites

  6. Incorporating Temperature-driven Seasonal Variation in Survival, Growth, and Reproduction Models for Small Fish

    EPA Science Inventory

    Seasonal variation in survival and reproduction can be a large source of prediction uncertainty in models used for conservation and management. A seasonally varying matrix population model is developed that incorporates temperature-driven differences in mortality and reproduction...

  7. Metals in benthic macrofauna and biogeochemical factors affecting their trophic transfer to wild fish around fish farm cages.

    PubMed

    Kalantzi, I; Papageorgiou, N; Sevastou, K; Black, K D; Pergantis, S A; Karakassis, I

    2014-02-01

    Benthic macroinvertebrates and wild fish aggregating in the vicinity of four Mediterranean fish farms were sampled. Concentrations of metals and other elements were measured in macrofaunal taxa and in fish tissues (muscle, liver, gills, bone, gonad, stomach, intestine, and stomach content). Biological and geochemical characteristics play an important role in metal accumulation in benthic invertebrates, and consequently in metal transfer to higher trophic levels. Macroinvertebrates accumulated lower concentrations of most metals and elements than their respective sediment, except As, P, Na, Zn and Cd. Elemental concentrations of benthic organisms increased with increasing sediment metal content, except Cd, and with % silt, refractory organic matter and chlorophyll-a of sediment due to the influence of sediment geochemistry on metal bioavailability. Tolerant species were found to accumulate higher concentrations of most metals and elements, except for Cd, than equilibrium species. The ecological and morphological characteristics of the benthic invertebrates can affect the bioaccumulation of metals and elements in macrobenthos. Hg and P were found to increase their concentrations from zoobenthos to wild fish aggregating around fish cages feeding on macrofauna.

  8. Caterpillar biomass depends on temperature and precipitation, but does not affect bird reproduction

    NASA Astrophysics Data System (ADS)

    Schöll, Eva Maria; Ohm, Judith; Hoffmann, Konstantin Frank; Hille, Sabine Marlene

    2016-07-01

    Complex changes in phenological events appear as temperatures are increasing: In deciduous forests bud burst, hatching of herbivorous caterpillars, egg laying and nestling time of birds when feeding chicks on caterpillars, may differentially shift into early season and alter synchronization. If timing of bird reproduction has to match with short periods of food availability, phenological mismatch could negatively affect reproductive success. Using a unique empirical approach along an altitudinal temperature gradient, we firstly asked whether besides temperature, also precipitation and leaf phenology interplay and affect caterpillar biomass, since impacts of rainfall on caterpillars have been largely neglected so far. Secondly, we asked whether abundance of caterpillars and thereby body mass of great tit nestlings, which are mainly fed with caterpillars, vary along the altitudinal temperature gradient. We demonstrated that next to temperature also precipitation and leaf phenology affected caterpillar biomass. In our beech forest, even along altitudes, caterpillars were available throughout the great tit breeding season but in highly variable amounts. Our findings revealed that although timing of leaf phenology and great tit breeding season were delayed with decreasing temperature, caterpillars occurred synchronously and were not delayed according to altitude. However, altitude negatively affected caterpillar biomass, but body mass of fledglings at high altitude sites was not affected by lower amounts of caterpillar biomass. This might be partially outweighed by larger territory sizes in great tits.

  9. An analysis of reproductive behavior in the mouthbreeding cichlid fish, Tilapia macrocephala (Bleeker).

    PubMed

    ARONSON, L R

    1949-01-01

    Qualitative descriptions and quantitative measurements of the patterns of reproductive behavior of the African mouthbreeding cichlid fish, Tilapia macrocephala (Bleeker), have been presented. These patterns have been grouped into three categories. The first, namely courtship, includes head-nods, approach-throat-puffs, body-quivers and tail-slaps. Most the females exhibited these courtship items during the observation periods, and at a relatively high frequency. The males performed these courtship acts at a considerably lower frequency. A high percentage of males showed some tail-slaps and body-quivers, and it is believed that if the entire spans of the pre-spawning activity of the pairs could have observed, all of the males would have performed these courtship patterns. On the other hand, it appears that a measurable portion of males do not head-nod or approach-throat-puff prior to the spawning. It is hypothesized that courtship behavior is an expression of the level of excitability of the individual. It may be thought of as a trophallactic process which through mutual stimulation serves to regulate the behavioral activities and physiological processes of the male and female so that well synchronized spawnings result. Nipping, which is closely related to courtship and which also appears to be mutually stimulating, was performed equally by the male female before the spawning, but nipping on the part of the female rises sharply directly after oviposition. Similar post-spawning increases on the part of the female were noted for all of the courtship patterns. It is suggested that the physiological changes following oviposition plus the presence of eggs are the factors responsible for this heightened activity. During the inter-spawning interval, a low level of courtship is in evidence, especially on the part of the females. The second group of reproductive patterns includes those acts which are concerned with the immediate preparation for spawing. Included here are nest

  10. Evidence of iteroparity in the widely distributed diadromous fish inanga Galaxias maculatus and potential implications for reproductive output.

    PubMed

    Stevens, J C B; Hickford, M J H; Schiel, D R

    2016-10-01

    Gaps in understanding variability among populations of inanga Galaxias maculatus in the timing of reproduction were addressed in southern New Zealand (NZ), where G. maculatus constitutes a declining fishery. Reproductive activity was delayed by 1 month on the west coast compared with the east coast and the west coast spawning season was prolonged into winter. The evidence for post-spawning survival of some fish was unequivocal from histological studies. These older and larger fish contributed disproportionately to egg production. Estimates of fecundity were considerably lower than those previously calculated for NZ populations. The importance of quality habitats being available during critical life history periods are highlighted. It was apparent that some streams supported fish that were larger and in better condition and that this translated into greatly increased fecundity. Future research should focus on whether this is a legacy of these fish experiencing better pre-settlement marine habitat as larvae, or higher quality instream habitat enhancing the growth and development of adults.

  11. Steroid receptor expression in the fish inner ear varies with sex, social status, and reproductive state

    PubMed Central

    2010-01-01

    Background Gonadal and stress-related steroid hormones are known to influence auditory function across vertebrates but the cellular and molecular mechanisms responsible for steroid-mediated auditory plasticity at the level of the inner ear remain unknown. The presence of steroid receptors in the ear suggests a direct pathway for hormones to act on the peripheral auditory system, but little is known about which receptors are expressed in the ear or whether their expression levels change with internal physiological state or external social cues. We used qRT-PCR to measure mRNA expression levels of multiple steroid receptor subtypes (estrogen receptors: ERα, ERβa, ERβb; androgen receptors: ARα, ARβ; corticosteroid receptors: GR2, GR1a/b, MR) and aromatase in the main hearing organ of the inner ear (saccule) in the highly social African cichlid fish Astatotilapia burtoni, and tested whether these receptor levels were correlated with circulating steroid concentrations. Results We show that multiple steroid receptor subtypes are expressed within the main hearing organ of a single vertebrate species, and that expression levels differ between the sexes. We also show that steroid receptor subtype-specific changes in mRNA expression are associated with reproductive phase in females and social status in males. Sex-steroid receptor mRNA levels were negatively correlated with circulating estradiol and androgens in both males and females, suggesting possible ligand down-regulation of receptors in the inner ear. In contrast, saccular changes in corticosteroid receptor mRNA levels were not related to serum cortisol levels. Circulating steroid levels and receptor subtype mRNA levels were not as tightly correlated in males as compared to females, suggesting different regulatory mechanisms between sexes. Conclusions This is the most comprehensive study of sex-, social-, and reproductive-related steroid receptor mRNA expression in the peripheral auditory system of any single

  12. Conspecific reproductive success affects age of recruitment in a great cormorant, Phalacrocorax carbo sinensis, colony.

    PubMed

    Frederiksen, M; Bregnballe, T

    2001-07-22

    Few studies have addressed the proximate factors affecting the age at which individuals of long-lived bird species are recruited into the breeding population. We use capture-recapture analysis of resightings of 16 birth cohorts of colour-ringed great cormorants, Phalacrocorax carbo sinensis, in a Danish colony to assess the evidence for two hypotheses: conspecific attraction (earlier recruitment when the colony is large) and conspecific reproductive success (earlier recruitment following years of high breeding success). For both males and females, conspecific reproductive success was the most important covariate explaining the interannual variation in age of recruitment; colony size was also important for females. These covariates explained nearly 60% of the year-to-year variation for both sexes. The age of recruitment increased for cohorts born after 1990, and this increase was correlated with a decline in breeding success in the colony; we interpret this as an indirect and delayed density-dependent effect. Females were recruited earlier than males (mean age of recruitment for cohorts born before 1990: 2.98 years versus 3.53 years); the most plausible reason for this is a skewed sex ratio in favour of males in the adult population. Recruitment of males may thus, to some extent, be constrained by the availability of females. This study provides the first evidence that conspecific reproductive success can affect the age at which individual birds start to breed.

  13. Chemical contaminants, health indicators, and reproductive biomarker responses in fish from rivers in the Southeastern United States

    USGS Publications Warehouse

    Hinck, J.E.; Blazer, V.S.; Denslow, N.D.; Echols, K.R.; Gale, R.W.; Wieser, C.; May, T.W.; Ellersieck, M.; Coyle, J.J.; Tillitt, D.E.

    2008-01-01

    Largemouth bass (Micropterus salmoides) and common carp (Cyprinus carpio) were collected from 13 sites located in the Mobile (MRB), Apalachicola-Flint-Chattahoochee (ARB), Savannah (SRB), and Pee Dee (PRB) River Basins to document spatial trends in accumulative chemical contaminants, health indicators, and reproductive biomarkers. Organochlorine residues, 2,3,7,8-tetrachlorodibenzo-p-dioxin-like activity (TCDD-EQ), and elemental contaminants were measured in composite samples of whole fish, grouped by species and gender, from each site. Mercury (Hg) and polychlorinated biphenyls (PCBs) were the primary contaminants of concern. Concentrations of Hg in bass samples from all basins exceeded toxicity thresholds for piscivorous mammals (> 0.1????g/g ww), juvenile and adult fish (> 0.2????g/g ww), and piscivorous birds (> 0.3????g/g ww). Total PCB concentrations in samples from the MRB, ARB, and PRB were > 480??ng/g ww and may be a risk to piscivorous wildlife. Selenium concentrations also exceeded toxicity thresholds (> 0.75????g/g ww) in MRB and ARB fish. Concentrations of other formerly used (total chlordanes, dieldrin, endrin, aldrin, mirex, and hexachlorobenzene) and currently used (pentachlorobenzene, pentachloroanisole, dacthal, endosulfan, ??-hexachlorocyclohexane, and methoxychlor) organochlorine residues were generally low or did not exceed toxicity thresholds for fish and piscivorous wildlife. TCDD-EQs exceeded wildlife dietary guidelines (> 5??pg/g ww) in MRB and PRB fish. Hepatic ethoxyresorufin O-deethylase (EROD) activity was generally greatest in MRB bass and carp. Altered fish health indicators and reproductive biomarker were noted in individual fish, but mean responses were similar among basins. The field necropsy and histopathological examination determined that MRB fish were generally in poorer health than those from the other basins, primarily due to parasitic infestations. Tumors were found in few fish (n = 5; 0.01%); ovarian tumors of smooth muscle

  14. Pentachlorophenol affected both reproductive and interrenal systems: In silico and in vivo evidence.

    PubMed

    Yang, Lihua; Zha, Jinmiao; Wang, Zijian

    2017-01-01

    The present study investigated the effects on reproductive and interrenal system by pentachlorophenol (PCP) using in silico and in vivo assays. Molecular docking results indicated interacting potency of PCP with steroid receptors (ERα, ERβ, AR, GR) but not Cytochrome P450 enzymes (CYPs). In the in vivo assay, sexually matured rare minnow (Gobiocypris rarus) was exposed to environmental relevant concentrations of PCP (0, 0.5, 5, 50 μg L(-1)). In male fish, 14-d exposure caused up-regulation of mRNA levels of hepatic erα, erβ, ar, gr, vtg and gonadal erα, vtg, ar, dmrt1, providing evidence for agonistic activities for steroid receptors by PCP. The up-regulated mRNA of gnrh, crf, pomc in the brain also indicated feed-forward responses of the hypothalamic-pituitary-gonadal/interrenal (HPG/I) axis. However, at 28th d the feed-forward response of the HPG axis seemed eased back and the HPI axis showed negative feedback responses. Corresponding changes including increases of plasma steroid hormones, inhibition of spermatogenesis, and decreased RSI were observed in male fish upon 28-d exposure to PCP. In the females, a transition from feed-forward responses to negative feedbacks of the HPG/I axis was also indicated by the transcriptional profiles at 14th and 28th day. Corresponding changes including increased E2, T and decreased C levels, degenerated ovaries, and decreased GSI and RSI were also observed. Overall, we concluded that PCP could interfere with steroid receptors, evoke responses of HPG/I axis, and finally result in adverse effects on reproductive and interrenal system in rare minnow at environmental relevant concentrations.

  15. Evidence for the involvement of dopamine in stress-induced suppression of reproduction in the cichlid fish Oreochromis mossambicus.

    PubMed

    Chabbi, A; Ganesh, C B

    2015-05-01

    In the present study, we examined whether stress-induced suppression of reproduction is mediated through the catecholaminergic neurotransmitter dopamine (DA) in the female cichlid fish Oreochromis mossambicus. In the first experiment, application of antibody against tyrosine hydroxylase (TH; a marker for DA) in brain sections revealed the presence of intensely stained TH immunoreactive cells in the preoptic area (POA) and nucleus preopticus (NPO) during the previtellogenic phase. These cells showed weak immunoreactivity during the vitellogenic and prespawning phases concomitant with darkly stained luteinising hormone (LH) immunoreactive content in the proximal pars distalis (PPD) of the pituitary gland and fully ripened follicles (stage V) in the ovary of control fish. However, in fish exposed to aquacultural stressors, TH secreting cells remained intensely stained in POA and NPO regions during the prespawning phase, indicating increased synthetic and secretory activity, which was reflected by a significantly higher DA content compared to controls. Increased DA activity as a result of stress was associated with a decrease in the LH immunoreactive content in the PPD and an absence of stage V follicles in the ovary. In the second experiment, administration of DA caused effects similar to those in stressed fish, whereas DA receptor antagonist domperidone (DOM) treatment significantly increased the LH content in the PPD and the number of stage V follicles in unstressed fish. On the other hand, treatment of stressed fish with DOM resulted in dark accumulations of LH immunoreactive content in the PPD accompanied by the presence of stage V follicles in the ovary. Taken together, these results suggest an additional pathway for the inhibitory effects of stress through dopaminergic neurones along the reproductive axis.

  16. Evaluation of reproductive health indicators in women affected by East Azarbaijan earthquake on August 2012

    PubMed Central

    Bahmanjanbeh, Farideh; Kohan, Shahnaz; Yarmohammadian, Mohammad Hossein; Haghshenas, Abbas

    2016-01-01

    Background: Ignoring reproductive health services during natural disasters leads to some negative consequences such as reduced access to contraceptive methods, sexual disorders, and pregnancy complications. Despite previous researches, there is still more need for research on this area of health. This study attempts to identify the indicators of reproductive health in the women affected by the East Azarbaijan earthquake on August 2012. Materials and Methods: In this descriptive study, reproductive health information pertaining to the years before, during, and after the earthquake were collected and compared in the health centers of the three affected cities including Ahar, Heriss, and Varzaghan as well as the health and forensics centers of the East Azarbaijan province in Iran by census method. Results: Findings indicated a decrease in live birth rate, general marriage fertility rate, stillbirth rate, contraceptive methods coverage, and prevalence of sexually transmitted diseases during and after the earthquake. Moreover, important indicators such as neonatal mortality rate and percentage of infants screened for breast milk, decreased during the disaster year in comparison with the years before and after. Other indicators such as preconception care, pregnancy first visit, rate of caesarian delivery, and under 1-year formula milk-fed infants’ percentages increased during the year of disaster in comparison with the years before and after. Conclusions: During the earthquake, some indicators of reproductive health have been reported to decrease whereas some others have gone through negative changes. Despite the partly favorable status of services, decision-makers and health service providers should pay more attention to the needs of women during disasters. PMID:27904635

  17. You Are What You Eat: Food Limitation Affects Reproductive Fitness in a Sexually Cannibalistic Praying Mantid

    PubMed Central

    Barry, Katherine L.

    2013-01-01

    Resource limitation during the juvenile stages frequently results in developmental delays and reduced size at maturity, and dietary restriction during adulthood can affect longevity and reproductive output. Variation in food intake can also result in alteration to the normal pattern of resource allocation among body parts or life-history stages. My primary aim in this study was to determine how varying juvenile and/or adult feeding regimes affect particular female and male traits in the sexually cannibalistic praying mantid Pseudomantis albofimbriata. Praying mantids are sit-and-wait predators whose resource intake can vary dramatically depending on environmental conditions within and across seasons, making them useful for studying the effects of feeding regime on various facets of reproductive fitness. In this study, there was a significant trend/difference in development and morphology for males and females as a result of juvenile feeding treatment, however, its effect on the fitness components measured for males was much greater than on those measured for females. Food-limited males were less likely to find a female during field enclosure experiments and smaller males were slower at finding a female in field-based experiments, providing some of the first empirical evidence of a large male size advantage for scrambling males. Only adult food limitation affected female fecundity, and the ability of a female to chemically attract males was also most notably affected by adult feeding regime (although juvenile food limitation did play a role). Furthermore, the significant difference/trend in all male traits and the lack of difference in male trait ratios between treatments suggests a proportional distribution of resources and, therefore, no trait conservation by food-limited males. This study provides evidence that males and females are under different selective pressures with respect to resource acquisition and is also one of very few to show an effect of juvenile

  18. You are what you eat: food limitation affects reproductive fitness in a sexually cannibalistic praying mantid.

    PubMed

    Barry, Katherine L

    2013-01-01

    Resource limitation during the juvenile stages frequently results in developmental delays and reduced size at maturity, and dietary restriction during adulthood can affect longevity and reproductive output. Variation in food intake can also result in alteration to the normal pattern of resource allocation among body parts or life-history stages. My primary aim in this study was to determine how varying juvenile and/or adult feeding regimes affect particular female and male traits in the sexually cannibalistic praying mantid Pseudomantis albofimbriata. Praying mantids are sit-and-wait predators whose resource intake can vary dramatically depending on environmental conditions within and across seasons, making them useful for studying the effects of feeding regime on various facets of reproductive fitness. In this study, there was a significant trend/difference in development and morphology for males and females as a result of juvenile feeding treatment, however, its effect on the fitness components measured for males was much greater than on those measured for females. Food-limited males were less likely to find a female during field enclosure experiments and smaller males were slower at finding a female in field-based experiments, providing some of the first empirical evidence of a large male size advantage for scrambling males. Only adult food limitation affected female fecundity, and the ability of a female to chemically attract males was also most notably affected by adult feeding regime (although juvenile food limitation did play a role). Furthermore, the significant difference/trend in all male traits and the lack of difference in male trait ratios between treatments suggests a proportional distribution of resources and, therefore, no trait conservation by food-limited males. This study provides evidence that males and females are under different selective pressures with respect to resource acquisition and is also one of very few to show an effect of juvenile

  19. An investigation into the factors affecting the natural reproduction of Opsaridium peringueyi

    NASA Astrophysics Data System (ADS)

    Moyo, N. A. G.

    An endangered freshwater fish, Opsaridium peringueyi, was studied from January, 2009 to December, 2009. The analysis of the environmental conditions indicated that the fish is found in streams with moderate to fast flow, high oxygen levels, a depth greater than 0.6 m and temperatures between 10 and 24 °C. O. peringueyi is sexually dimorphic with males growing at a faster rate and attaining a larger size than females. The breeding biology of this species was investigated in glass aquarium tanks. The spawning behaviour is described for the first time. The breeding colour of the male is deep red on the operculum, ventral part, caudal and ventral fins. The breeding colour in the female is the same as the male except the red colour is lighter. The breeding of O. peringueyi is a four stage process which begins with the appearance of breeding colour culminating in the laying of eggs after courtship. Temperature, flow-rate, conductivity and substrate were identified as the environmental cues important in the reproduction of this species. All these factors had a significant effect on the breeding activity of O. peringueyi. The possible effect of climate change on O. peringueyi is discussed.

  20. Climate change alters the reproductive phenology and investment of a lacustrine fish, the three-spine stickleback.

    PubMed

    Hovel, Rachel A; Carlson, Stephanie M; Quinn, Thomas P

    2016-11-30

    High-latitude lakes are particularly sensitive to the effects of global climate change, demonstrating earlier ice breakup, longer ice-free seasons, and increased water temperatures. Such physical changes have implications for diverse life-history traits in taxa across entire lake food webs. Here, we use a five-decade time series from an Alaskan lake to explore effects of climate change on growth and reproduction of a widely distributed lacustrine fish, the three-spine stickleback (Gasterosteus aculeatus). We used multivariate autoregressive state-space (MARSS) models to describe trends in the mean length for multiple size classes and to explore the influence of physical (date of ice breakup, surface water temperature) and biological (density of con- and heterospecifics) factors. As predicted, mean size of age 1 and older fish at the end of the growing season increased across years with earlier ice breakup and warmer temperatures. In contrast, mean size of age 0 fish decreased over time. Overall, lower fish density and warmer water temperatures were associated with larger size for all cohorts. Earlier ice breakup was associated with larger size for age 1 and older fish but, paradoxically, with smaller size of age 0 fish. To explore this latter result, we used mixing models on age 0 size distributions, which revealed an additional cohort in years with early ice breakup, lowering the mean size of age 0 fish. Moreover, early ice breakup was associated with earlier breeding, evidenced by earlier capture of age 0 fish. Our results suggest that early ice breakup altered both timing and frequency of breeding; three-spine stickleback spawned earlier and more often in response to earlier ice breakup date. While previous studies have shown the influence of changing conditions in northern lakes on breeding timing and growth, this is the first to document increased breeding frequency, highlighting another pathway by which climate change can alter the ecology of northern lakes.

  1. Application of endocrine disruptor screening program fish short-term reproduction assay: Reproduction and endocrine function in fathead minnow (Pimephales promelas) and killifish (Fundulus heteroclitus) exposed to Bermuda pond sediment.

    PubMed

    Fort, Douglas J; Mathis, Michael; Fort, Chelsea E; Fort, Hayley M; Bacon, Jamie P

    2015-06-01

    A modified tier 1 Endocrine Disruptor Screening Program (EDSP) 21-d fish short-term reproduction assay (FSTRA) was used to evaluate the effects of sediment exposure from freshwater and brackish ponds in Bermuda on reproductive fecundity and endocrine function in fathead minnow (Pimephales promelas) and killifish (Fundulus heteroclitus). Reproductively active male and female fish were exposed to control sediment and sediment from 2 freshwater ponds (fathead minnow) and 2 marine ponds (killifish) contaminated with polyaromatic hydrocarbons and metals via flow-through exposure for 21 d. Reproductive fecundity was monitored daily. At termination, the status of the reproductive endocrine system was assessed by the gonadosomatic index, gonadal histology, plasma steroids (estrogen [E2], testosterone [T], and 11-ketotestosterone [11-KT]), steroidogenic enzymes (aromatase and combined 3β/17β -hydroxysteroid dehydrogenase [3β/17β-HSD]), and plasma vitellogenin (VTG). Decreased reproductive fecundity, lower male body weight, and altered endocrinological measures of reproductive status were observed in both species. Higher plasma T levels in female minnows and 11-KT levels in both male and female minnows and female killifish exposed to freshwater and brackish sediments, respectively. Decreased female E2 and VTG levels and gonadal cytochrome P19 (aromatase) activity were also found in sediment exposed females from both species. No effect on female 3β/17β-HSD activity was found in either species. The FSTRA provided a robust model capable of modification to evaluate reproductive effects of sediment exposure in fish.

  2. Fish in shallow areas in Moreton Bay, Queensland and factors affecting their distribution

    NASA Astrophysics Data System (ADS)

    Weng, H. T.

    1990-06-01

    Five shallow areas (< 4 m in depth) in Moreton Bay were selected to examine fish communities. These areas can be categorized as sand-drifting, sea grass, river mouth, mangrove fringe and sewage outlet. A total of 86 fish species were recorded. Five species (6%) were regarded as true marine fish but these were of rare occurrence (0·5%). Four species (5%) were highly abundant (51%) and 57 species (66%) were represented by low numbers of fish (5%). The sewage outlet and the river mouth sites were found to contain the highest number of fish with relatively low numbers of species. The sand-drifting and the sea grass sites were different in fish fauna, and both were different from the remaining three sites which were of high similarity in fish faunal groups. Food availability, preference for habitats, sea grass vegetation, juvenile/adult segregation, season of juvenile recruitment and hydrological characteristics were thought to be important factors affecting the distribution of these species of fish.

  3. Reproductive biomarkers responses induced by xenoestrogens in the characid fish Astyanax fasciatus inhabiting a South American reservoir: an integrated field and laboratory approach.

    PubMed

    Prado, Paula S; Pinheiro, Ana Paula B; Bazzoli, Nilo; Rizzo, Elizete

    2014-05-01

    Field studies evaluating the effects of endocrine disruption chemicals (EDCs) on the fish reproduction are scarce worldwide. The goal of this study was to assess hepatic levels of vitellogenin (Vtg), zona radiata proteins (Zrp) and insulin-like growth factors (IGF-I and IGF-II), and relating them to reproductive endpoints in a wild fish population habiting a reservoir that receive domestic sewage, agricultural and industrial residues. Adult fish Astyanax fasciatus were sampled during the reproductive season in five sites from the Furnas Reservoir, Grande River, and Paraguay-Paraná basin. As a control to field data, fish were experimentally exposed via dietary intake, to oestradiol benzoate (OB) for 7 days. Fish from site with little anthropogenic interference showed hepatic levels of Vtg, Zrp and IGF-I and IGF-II similar to those from the non-treated experimental group. In sites located immediately downstream from the municipal wastewater discharges, the water total oestrogen was >120 ng/l, and male fish displayed increased Vtg and Zrp and decreased IGF-I levels similar to OB treated fish. In females, levels of Vtg, Zrp, IGF-I and IGF-II suggest an impairment of final oocyte maturation and spawning, as also detected by frequency of over-ripening, follicular atresia and fecundity. At the sites that receive agricultural and industrial residues, the water total oestrogen was <50 ng/l and females showed decreased Zrp and increased IGF-II levels associated to reduced diameter of vitellogenic follicles, indicating an inhibition of oocyte growth. Overall, the current study reports oestrogenic contamination impairing the reproduction of a wild fish from a hydroeletric reservoir and, the data contribute to improving the current knowledge on relationship between hepatic Vtg, Zrp and IGF-I and IGF-II, and reproductive endpoints in a teleost fish. In addition, our data point out novel reproductive biomarkers (IGF-I, IGF-II and over-ripening) to assessing xenoestrogenic

  4. Reproduction of Pseudocalanus newmani (Copepoda: Calanoida) is deleteriously affected by diatom blooms A field study

    NASA Astrophysics Data System (ADS)

    Halsband-Lenk, Claudia; Pierson, James J.; Leising, Andrew W.

    2005-11-01

    Copepod secondary production has traditionally been linked to the spring diatom bloom in temperate and high latitudes, but laboratory studies have recently challenged this view and have shown either reduced fecundity or viability of offspring when copepods were fed high concentrations of - mostly unialgal - diatoms. However, field evidence that diatoms affect copepod reproduction is still scarce. We analyzed the reproductive response of a common, small calanoid copepod of the boreal Pacific, Pseudocalanus newmani, to spring diatom blooms in Dabob Bay, a semi-enclosed fjord of Puget Sound, Washington, USA. Abundance patterns, egg production rates, egg hatching success, and naupliar viability of the egg-carrying copepod were examined between February and early May in the years 2002-2004. The population underwent strong variations in abundance during both years, with high abundance of all stages from February to mid-March, but dramatically decreasing individual numbers later in spring. A recovery to higher numbers occurred in July. While egg production rates were independent of chlorophyll concentrations, the reproductive success of P. newmani was negatively affected by certain phytoplankton bloom conditions. Hatching success and - more markedly - naupliar survival were reduced following peaks of Thalassiosira species that were producing anti-mitotic aldehydes, but were high during periods when phytoplankton blooms were more diverse or dominated by other prey taxa including diatoms. As a consequence, recruitment of the naupliar population was considerably affected by the Thalassiosira blooms. This study shows for the first time that the so-called diatom effect operates in nature when all prerequisites - (1) high concentration of aldehyde producers, (2) few prey alternatives, and (3) feeding of copepods on these algae - are given. However, the effect was transient in Dabob Bay and may be so in other pelagic ecosystems. It remains to discern the potential sources of

  5. Does catch and release affect the mating system and individual reproductive success of wild Atlantic salmon (Salmo salar L.)?

    PubMed

    Richard, Antoine; Dionne, Mélanie; Wang, Jinliang; Bernatchez, Louis

    2013-01-01

    In this study, we documented the breeding system of a wild population of Atlantic salmon (Salmo salar L.) by genetically sampling every returning adult and assessed the determinants of individual fitness. We then quantified the impacts of catch and release (C&R) on mating and reproductive success. Both sexes showed high variance in individual reproductive success, and the estimated standardized variance was higher for males (2.86) than for females (0.73). We found a weak positive relationship between body size and fitness and observed that fitness was positively correlated with the number of mates, especially in males. Mature male parr sired 44% of the analysed offspring. The impact of C&R on the number of offspring was size dependent, as the reproductive success of larger fish was more impaired than smaller ones. Also, there was an interactive negative effect of water temperature and air exposure time on reproductive success of C&R salmon. This study improves our understanding of the complex reproductive biology of the Atlantic salmon and is the first to investigate the impact of C&R on reproductive success. Our study expands the management toolbox of appropriate C&R practices that promote conservation of salmon populations and limit negative impacts on mating and reproductive success.

  6. Effect of estrogenic activity, and phytoestrogen and organochlorine pesticide contents in an experimental fish diet on reproduction and hepatic vitellogenin production in medaka (Oryzias latipes).

    PubMed

    Inudo, Makiko; Ishibashi, Hiroshi; Matsumura, Naomi; Matsuoka, Munekazu; Mori, Taiki; Taniyama, Shigeto; Kadokami, Kiwao; Koga, Minoru; Shinohara, Ryota; Hutchinson, T H; Iguchi, Taisen; Arizono, Koji

    2004-12-01

    Endocrine-disrupting chemicals (EDCs) are giving rise to serious concerns for humans and wildlife. Phytoestrogens, such as daidzein and genistein in plants, and organochlorine pesticides are suspected EDCs, because their chemical structure is similar to that of natural or synthetic estrogens and they have estrogenic activity in vitro and in vivo. We assessed estrogenic activity and dietary phytoestrogen and organochlorine pesticide contents of various fish diets made in the United Kingdom, and compared them with those features of diets made in Japan that were tested in a previous study. Genistein and daidzein were detected in all of the diets. Using an in vitro bioassay, many of these diets had higher activation of estrogen beta-receptors than estrogen alpha-receptors. Organochlorine pesticides such as hexachlorobenzene, beta-benzene hexachloride (BHC), and gamma-BHC were detected in all fish diets. On the basis of these data, we investigated the effect of differing dietary phytoestrogen content in Japanese fish diets on hepatic vitellogenin production and reproduction (fecundity and fertility) in medaka (Oryzias latipes). Assessment of the effects of a 28-day feeding period on reproduction of paired medaka did not indicate significant differences in the number of eggs produced and fertility among all feeding groups. However, hepatic vitellogenin values were significantly higher for male medaka fed diet C (genistein, 58.5 +/- 0.6 microg/g; daidzein, 37.3 +/- 0.2 microg/g) for 28 days compared with those fed diet A (genistein, < 0.8 microg/g; daidzein, < 0.8 microg/g) or diet B (genistein, 1.4 +/- 0.1 microg/g; daidzein, 2.0 +/- 0.1 microg/g). Our findings indicate that fish diets containing high amounts of phytoestrogens, such as diet C, have the potential to induce hepatic vitellogenin production in male medaka, even if reproductive parameters are unaffected. Therefore, some diets, by affecting vitellogenin production in males, may alter estrogenic activity of in

  7. Fish pre-acclimation temperature only modestly affects cadmium toxicity in Atlantic salmon hepatocytes.

    PubMed

    Olsvik, Pål A; Søfteland, Liv; Hevrøy, Ernst M; Rasinger, Josef D; Waagbø, Rune

    2016-04-01

    An emerging focus in environmental toxicology is how climate change will alter bioavailability and uptake of contaminants in organisms. Ectothermic animals unable to adjust their temperature by local migration, such as farmed fish kept in net pens, may become more vulnerable to contaminants in warmer seas. The aim of this work was to study cadmium (Cd) toxicity in cells obtained from fish acclimated to sub-optimal growth temperature. Atlantic salmon hepatocytes, harvested from fish pre-acclimated either at 15°C (optimal growth temperature) or 20°C (heat-stressed), were exposed in vitro to two concentrations of Cd (control, 1 and 100µM Cd) for 48h. Cd-induced cytotoxicity, determined with the xCELLigence system, was more pronounced in cells from fish pre-acclimated to a high temperature than in cells from fish grown at optimal temperature. A feed spiked with antioxidants could not ameliorate the Cd-induced cytotoxicity in cells from temperature-stressed fish. At the transcriptional level, Cd exposure affected 11 out of 20 examined genes, of which most are linked to oxidative stress. The transcriptional levels of a majority of the altered genes were changed in cells harvested from fish grown at sub-optimal temperature. Interaction effects between Cd exposure and fish pre-acclimation temperature were seen for four transcripts, hmox1, mapk1, fth1 and mmp13. Overall, this study shows that cells from temperature-stressed fish are modestly more vulnerable to Cd stress, and indicate that mechanisms linked to oxidative stress may be differentially affected in temperature-stressed cells.

  8. Long-term reproductive and behavioral toxicity of anthracene to fish in the presence of solar ultraviolet radiation

    SciTech Connect

    Hall, A.T.; Oris, J.T.

    1994-12-31

    The long-term, low-level effects of anthracene in the presence of solar ultraviolet radiation (SUVR) were examined in the fathead minnow (Pimephales promelas). Adult fish exposed to anthracene exhibited reduced egg laying capacity, with altered oocyte maturation as a potential mechanism of action. Eggs and larvae maternally exposed to anthracene exhibited reduced hatching success and severe developmental abnormalities when incubated under SUVR. The combination of reduced egg output and developmental effects resulted in an inhibition in reproductive capacity in the range of 70--100%. Maternal transfer of anthracene to eggs was efficient; the BCF was 717 for maternally exposed eggs. However, anthracene deputation from eggs after oviposition with only maternal PAH exposure was rapid; anthracene half-life from eggs equaled 1.3 days. Exposure to anthracene under SUVR altered locomotor activity patterns in fathead minnows by inducing hyperactivity or hypoactivity during the light or dark phases of the photoperiod, respectively. Altered activity patterns indicated potential effects of anthracene on the nervous system and/or pineal gland. These alterations disrupted normal activity patterns and reproductive behaviors, and thus have major implications on a fish`s ability to survive and reproduce. Anthracene, a model phototoxic PAH, has many potential sites of toxic action, and any organism exposed to such contaminants will be an considerable SUVR-enhanced risk in the environment.

  9. Catecholaminergic innervation of central and peripheral auditory circuitry varies with reproductive state in female midshipman fish, Porichthys notatus.

    PubMed

    Forlano, Paul M; Ghahramani, Zachary N; Monestime, Camillia M; Kurochkin, Philip; Chernenko, Alena; Milkis, Dmitriy

    2015-01-01

    In seasonal breeding vertebrates, hormone regulation of catecholamines, which include dopamine and noradrenaline, may function, in part, to modulate behavioral responses to conspecific vocalizations. However, natural seasonal changes in catecholamine innervation of auditory nuclei is largely unexplored, especially in the peripheral auditory system, where encoding of social acoustic stimuli is initiated. The plainfin midshipman fish, Porichthys notatus, has proven to be an excellent model to explore mechanisms underlying seasonal peripheral auditory plasticity related to reproductive social behavior. Recently, we demonstrated robust catecholaminergic (CA) innervation throughout the auditory system in midshipman. Most notably, dopaminergic neurons in the diencephalon have widespread projections to auditory circuitry including direct innervation of the saccule, the main endorgan of hearing, and the cholinergic octavolateralis efferent nucleus (OE) which also projects to the inner ear. Here, we tested the hypothesis that gravid, reproductive summer females show differential CA innervation of the auditory system compared to non-reproductive winter females. We utilized quantitative immunofluorescence to measure tyrosine hydroxylase immunoreactive (TH-ir) fiber density throughout central auditory nuclei and the sensory epithelium of the saccule. Reproductive females exhibited greater density of TH-ir innervation in two forebrain areas including the auditory thalamus and greater density of TH-ir on somata and dendrites of the OE. In contrast, non-reproductive females had greater numbers of TH-ir terminals in the saccule and greater TH-ir fiber density in a region of the auditory hindbrain as well as greater numbers of TH-ir neurons in the preoptic area. These data provide evidence that catecholamines may function, in part, to seasonally modulate the sensitivity of the inner ear and, in turn, the appropriate behavioral response to reproductive acoustic signals.

  10. Catecholaminergic Innervation of Central and Peripheral Auditory Circuitry Varies with Reproductive State in Female Midshipman Fish, Porichthys notatus

    PubMed Central

    Forlano, Paul M.; Ghahramani, Zachary N.; Monestime, Camillia M.; Kurochkin, Philip; Chernenko, Alena; Milkis, Dmitriy

    2015-01-01

    In seasonal breeding vertebrates, hormone regulation of catecholamines, which include dopamine and noradrenaline, may function, in part, to modulate behavioral responses to conspecific vocalizations. However, natural seasonal changes in catecholamine innervation of auditory nuclei is largely unexplored, especially in the peripheral auditory system, where encoding of social acoustic stimuli is initiated. The plainfin midshipman fish, Porichthys notatus, has proven to be an excellent model to explore mechanisms underlying seasonal peripheral auditory plasticity related to reproductive social behavior. Recently, we demonstrated robust catecholaminergic (CA) innervation throughout the auditory system in midshipman. Most notably, dopaminergic neurons in the diencephalon have widespread projections to auditory circuitry including direct innervation of the saccule, the main endorgan of hearing, and the cholinergic octavolateralis efferent nucleus (OE) which also projects to the inner ear. Here, we tested the hypothesis that gravid, reproductive summer females show differential CA innervation of the auditory system compared to non-reproductive winter females. We utilized quantitative immunofluorescence to measure tyrosine hydroxylase immunoreactive (TH-ir) fiber density throughout central auditory nuclei and the sensory epithelium of the saccule. Reproductive females exhibited greater density of TH-ir innervation in two forebrain areas including the auditory thalamus and greater density of TH-ir on somata and dendrites of the OE. In contrast, non-reproductive females had greater numbers of TH-ir terminals in the saccule and greater TH-ir fiber density in a region of the auditory hindbrain as well as greater numbers of TH-ir neurons in the preoptic area. These data provide evidence that catecholamines may function, in part, to seasonally modulate the sensitivity of the inner ear and, in turn, the appropriate behavioral response to reproductive acoustic signals. PMID

  11. Hormonal, biochemical, and hematological profiles in female camels (Camelus dromedarius) affected with reproductive disorders.

    PubMed

    Ali, A; Tharwat, M; Al-Sobayil, F A

    2010-04-01

    The aim of this study was to assess the blood profiles in female camels affected with common reproductive disorders. Estradiol-17beta (E(2)), progesterone (P(4)), thyroxin (T(4)), zinc (Zn), copper (Cu), calcium (Ca), phosphorus (P), magnesium (Mg), cholesterol, glucose, triglycerides, total protein, albumin, globulin, hematocrite, and total and differential white blood cell counts (WBC) were determined in blood of female camels affected with endometritis (n=15), vaginal adhesions (n=15), and ovarian cysts (n=15). Normal cyclic animals were used as controls (n=15). Diagnosis of reproductive disorders was based on transrectal palpation, ultrasonographic examination, and exploration of the vagina. Increased WBC counts (P=0.03) and a tendency for neutrophelia (P=0.05) were noted in female camels with vaginal adhesions. These animals were also characterized by having higher concentration of serum P(4) (P=0.0001), T(4) (P=0.001) and total protein (P=0.007), in comparison with female camels with endometritis, ovarian cysts, or controls. Animals having ovarian cysts with thin walls and homogenous hypoechogenic contents had greater serum E(2) (P=0.001) and P(4) (P=0.0001) than those having ovarian cysts with thick walls and non-homogenous echogenic contents. Animals with endometritis, vaginal adhesions, and ovarian cysts revealed lower serum Zn concentration than that of control group (P=0.003). Other blood parameters did not differ significantly compared to controls. In conclusion, this is the first report characterizing blood constituents in female camels with various reproductive disorders. These profiles may be valuable in clarifying the etio-pathogenesis of these disorders.

  12. Removal of the local geomagnetic field affects reproductive growth in Arabidopsis.

    PubMed

    Xu, Chunxiao; Wei, Shufeng; Lu, Yan; Zhang, Yuxia; Chen, Chuanfang; Song, Tao

    2013-09-01

    The influence of the geomagnetic field-removed environment on Arabidopsis growth was investigated by cultivation of the plants in a near-null magnetic field and local geomagnetic field (45 µT) for the whole growth period under laboratory conditions. The biomass accumulation of plants in the near-null magnetic field was significantly suppressed at the time when plants were switching from vegetative growth to reproductive growth compared with that of plants grown in the local geomagnetic field, which was caused by a delay in the flowering of plants in the near-null magnetic field. At the early or later growth stage, no significant difference was shown in the biomass accumulation between the plants in the near-null magnetic field and local geomagnetic field. The average number of siliques and the production of seeds per plant in the near-null magnetic field was significantly lower by about 22% and 19%, respectively, than those of control plants. These resulted in a significant reduction of about 20% in the harvest index of plants in the near-null magnetic field compared with that of the controls. These results suggest that the removal of the local geomagnetic field negatively affects the reproductive growth of Arabidopsis, which thus affects the yield and harvest index.

  13. Does mating behaviour affect connectivity in marine fishes? Comparative population genetics of two protogynous groupers (Family Serranidae).

    PubMed

    Portnoy, D S; Hollenbeck, C M; Renshaw, M A; Cummings, N J; Gold, J R

    2013-01-01

    Pelagic larval duration (PLD) has been hypothesized to be the primary predictor of connectivity in marine fishes; however, few studies have examined the effects that adult reproductive behaviour may have on realized dispersal. We assessed gene flow (connectivity) by documenting variation in microsatellites and mitochondrial DNA sequences in two protogynous species of groupers, the aggregate spawning red hind, Epinephelus guttatus, and the single-male, harem-spawning coney, Cephalopholis fulva, to ask whether reproductive strategy affects connectivity. Samples of both species were obtained from waters off three islands (Puerto Rico, St. Thomas and St. Croix) in the Caribbean Sea. Despite the notion that aggregate spawning of red hind may facilitate larval retention, stronger signals of population structure were detected in the harem-spawning coney. Heterogeneity and/or inferred barriers, based on microsatellites, involved St. Croix (red hind and coney) and the west coast of Puerto Rico (coney). Heterogeneity and/or inferred barriers, based on mitochondrial DNA, involved St. Croix (coney only). Genetic divergence in both species was stronger for microsatellites than for mitochondrial DNA, suggesting sex-biased dispersal in both species. Long-term migration rates, based on microsatellites, indicated asymmetric gene flow for both species in the same direction as mean surface currents in the region. Red hind had higher levels of variation in microsatellites and lower levels of variation in mitochondrial DNA. Long-term effective size and effective number of breeders were greater for red hind; estimates of θ(f) , a proxy for long-term effective female size, were the same in both species. Patterns of gene flow in both species appear to stem in part from shared aspects of larval and adult biology, local bathymetry and surface current patterns. Differences in connectivity and levels of genetic variation between the species, however, likely stem from differences in behaviour

  14. Reproductive history and nest environment are correlated with circulating androgen and glucocorticoid concentrations in a parental care-providing teleost fish.

    PubMed

    O'Connor, Constance M; Barthel, Brandon L; Gilmour, Kathleen M; Philipp, David P; Van Der Kraak, Glen; Cooke, Steven J

    2012-01-01

    Using a long-term study population of wild smallmouth bass Micropterus dolomieu in a connected river-lake system, we investigated whether circulating glucocorticoid (cortisol) and androgen (testosterone) concentrations are influenced by reproductive investment and nesting environment in fish providing nest-guarding paternal care. For all individuals, we collected measures of reproductive history and the value of current parental care. We assessed nest environment and monitored individuals to quantify seasonal reproductive success. Finally, we measured circulating cortisol concentrations following a standardized stressor and circulating testosterone concentrations. Using general linear models, we found that poststress circulating cortisol concentrations were positively related to water temperature and were higher in fish nesting in the river than in the lake. Circulating testosterone concentrations were negatively related to water temperature and were higher in reproductively experienced fish. When considering the factors that influence reproductive success, we found that only parental size was positively related to current nest success. In summary, the results demonstrate that nesting environment is correlated with parental stress responses during parental care, while reproductive history and nesting environment are correlated with circulating androgen concentrations. Collectively, these results offer insight into the roles of both glucocorticoid and androgen steroid hormones during parental care in teleost fish.

  15. Reproductive biomarkers responses induced by xenoestrogens in the characid fish Astyanax fasciatus inhabiting a South American reservoir: An integrated field and laboratory approach

    SciTech Connect

    Prado, Paula S.; Pinheiro, Ana Paula B.; Bazzoli, Nilo; Rizzo, Elizete

    2014-05-01

    Field studies evaluating the effects of endocrine disruption chemicals (EDCs) on the fish reproduction are scarce worldwide. The goal of this study was to assess hepatic levels of vitellogenin (Vtg), zona radiata proteins (Zrp) and insulin-like growth factors (IGF-I and IGF-II), and relating them to reproductive endpoints in a wild fish population habiting a reservoir that receive domestic sewage, agricultural and industrial residues. Adult fish Astyanax fasciatus were sampled during the reproductive season in five sites from the Furnas Reservoir, Grande River, and Paraguay–Paraná basin. As a control to field data, fish were experimentally exposed via dietary intake, to oestradiol benzoate (OB) for 7 days. Fish from site with little anthropogenic interference showed hepatic levels of Vtg, Zrp and IGF-I and IGF-II similar to those from the non-treated experimental group. In sites located immediately downstream from the municipal wastewater discharges, the water total oestrogen was >120 ng/l, and male fish displayed increased Vtg and Zrp and decreased IGF-I levels similar to OB treated fish. In females, levels of Vtg, Zrp, IGF-I and IGF-II suggest an impairment of final oocyte maturation and spawning, as also detected by frequency of over-ripening, follicular atresia and fecundity. At the sites that receive agricultural and industrial residues, the water total oestrogen was <50 ng/l and females showed decreased Zrp and increased IGF-II levels associated to reduced diameter of vitellogenic follicles, indicating an inhibition of oocyte growth. Overall, the current study reports oestrogenic contamination impairing the reproduction of a wild fish from a hydroeletric reservoir and, the data contribute to improving the current knowledge on relationship between hepatic Vtg, Zrp and IGF-I and IGF-II, and reproductive endpoints in a teleost fish. In addition, our data point out novel reproductive biomarkers (IGF-I, IGF-II and over-ripening) to assessing xenoestrogenic

  16. The transmission of light affect the color reproduction of plastic print

    NASA Astrophysics Data System (ADS)

    Chen, Jie; Zhang, Yi-xin; Shi, Gongcheng

    2011-01-01

    By analyzing the different paths that the incident light traverses in the printing, the paper aims to study the effect the transmission of light produces on the color reproduction of the plastic printing. The article also analyzes object characteristics about the three color properties and the color density, so as to make an accurate prediction on the color reproduction of the printing where ink is printed on the end of the plastic base directly. In the research, the incident light on the plastic print are divided into two parts: the reflection of diffuse light in the ink and the optical multi-layer internal reflection of the light through ink layer onto the plastic substrate. In this paper, we use kubelka-munk theory to analyze the transmission of the incident light on the surface of the printing product and Clapper-Yule theory to analyze the incident light which through the ink to the plastic film surface. When the incident light through the ink to the film surface, we have a series of mutually parallel reflected beam and refracted beam, and then obtain the synthesis of the reflected light complex amplitude, using the similar methods to obtain the total reflected and refraction light intensity. Combining the total reflection light intensity through the plastic substrate and the overall reflectivity through a plastic print surface by the kubelka-munk theory, color density and light transmission factor of the plastic substrate can be drawn in the formula: D ∞ f (δ,d,i1 ). From the above equation, we can find that optical phase retardation δ, the thickness of plastic d and the angle of incidence on the plastic surface i1 affect the color reproduction of plastic print.

  17. Delayed breeding affects lifetime reproductive success differently in male and female green woodhoopoes.

    PubMed

    Hawn, Amanda T; Radford, Andrew N; du Plessis, Morné A

    2007-05-15

    In cooperatively breeding species, many individuals only start breeding long after reaching physiological maturity [1], and this delay is expected to reduce lifetime reproductive success (LRS) [1-3]. Although many studies have investigated how nonbreeding helpers might mitigate the assumed cost of delayed breeding (reviewed in [3]), few have directly quantified the cost itself [4, 5] (but see [6, 7]). Moreover, although life-history tradeoffs frequently influence the sexes in profoundly different ways [8, 9], it has been generally assumed that males and females are similarly affected by a delayed start to breeding [7]. Here, we use 24 years of data to investigate the sex-specific cost of delayed breeding in the cooperatively breeding green woodhoopoe (Phoeniculus purpureus) and show that age at first breeding is related to LRS differently in males and females. As is traditionally expected, males that started to breed earlier in life had greater LRS than those that started later. However, females showed the opposite pattern: Those individuals that started to breed later in life actually had greater LRS than those that started earlier. In both sexes, the association between age at first breeding and LRS was driven by differences in breeding-career length, rather than per-season productivity. We hypothesize that the high mortality rate of young female breeders, and thus their short breeding careers, is related to a reduced ability to deal with the high physiological costs of reproduction in this species. These results demonstrate the importance of considering sex-specific reproductive costs when estimating the payoffs of life-history decisions and bring into question the long-held assumption that delayed breeding is necessarily costly.

  18. Relation of water level and fish availability to wood stork reproduction in the southern Everglades, Florida

    USGS Publications Warehouse

    Kushlan, James A.; Ogden, John C.; Higer, Aaron L.

    1975-01-01

    The wood stork is a species of colonial wading bird in the Everglades that is most sensitive to changes in the availability of food. Previous studies have shown that the initiation and success of wood stork nesting depends on high densities of fish concentrated in ponds and other catchment basins during the dry season. The extreme dependence of the wood stork on the cyclic hydrologic regime of the southern Florida wetlands makes it an indicator of the well-being and ecological stability of the Everglades. The wood stork has declined in numbers over the last 25 years. One reason for the decline in wood stork population was the change in the hydrologic regimen of the Everglades which affected the feeding habitat and the food production. The fish on which the wood stork feeds increase in density during the dry season as water levels fall. In the Everglades marsh, densities were highest in front of the drying edge of surface water at a depth of about 0.3 m. Dry-season densities were greatest when a drought occurred the previous year. Historically wood stork nesting success was associated with high summer water levels, high rates of surface-water discharge and high rates of drying. Before the closure of the south side of Conservation Area 3 in 1962, years of successful and unsuccessful nesting were characterized by different patterns of drying. These patterns changed after 1962 and generally the predictability of successful nesting breaks down thereafter. Only two nesting years after 1962 were successful and in only one of these was the drying rate similar to years of successful nesting before 1962. Two other potentially successful years failed after 1962. This suggests that further changes in the hydrobiological relations occurred within the Everglades after 1962. Lack of successful nesting after 1962 can be attributed in large part to late colony formation and the interruption of nesting by winter rainfall. In this period (1962-72), colonies formed earlier in years of

  19. Maternally transferred dioxin-like compounds can affect the reproductive success of European eel.

    PubMed

    Foekema, Edwin M; Kotterman, Michiel; de Vries, Pepijn; Murk, Albertinka J

    2016-01-01

    Reported concentrations of dioxin-like compounds accumulated in the European eel (Anguilla anguilla) were used to perform a risk assessment for eel larval survival, taking into account a modeled amplification of tissue concentrations with a factor of 1.33 during spawning migration. The calculated concentrations of dioxin-like compounds finally deposited in the eggs were compared with the internal effect concentrations for survival of early life stages of the European eel; these concentrations, by lack of experimental data, were estimated from a sensitivity distribution based on literature data by assuming that eel larvae are among the 10% most sensitive teleost fish species. Given concentrations of dioxin-like contaminants and assuming a relatively high sensitivity, it can be expected that larvae from eggs produced by eel from highly contaminated locations in Europe will experience increased mortality as a result of maternally transferred dioxin-like contaminants. As historical persistent organic pollutant concentrations in eel tissue were higher, this impact must have been stronger in the past. Potential effects of other compounds or effects on the migration, condition, and fertility of the parental animals were not taken into account. It is important to further study the overall impact of contaminants on the reproductive success of the European eel as this may have been underestimated until now.

  20. Larval traits carry over to affect post-settlement behaviour in a common coral reef fish.

    PubMed

    Dingeldein, Andrea L; White, J Wilson

    2016-07-01

    Most reef fishes begin life as planktonic larvae before settling to the reef, metamorphosing and entering the benthic adult population. Different selective forces determine survival in the planktonic and benthic life stages, but traits established in the larval stage may carry over to affect post-settlement performance. We tested the hypothesis that larval traits affect two key post-settlement fish behaviours: social group-joining and foraging. Certain larval traits of reef fishes are permanently recorded in the rings in their otoliths. In the bluehead wrasse (Thalassoma bifasciatum), prior work has shown that key larval traits recorded in otoliths (growth rate, energetic condition at settlement) carry over to affect post-settlement survival on the reef, with higher-larval-condition fish experiencing less post-settlement mortality. We hypothesized that this selective mortality is mediated by carry-over effects on post-settlement antipredator behaviours. We predicted that better-condition fish would forage less and be more likely to join groups, both behaviours that would reduce predation risk. We collected 550 recently settled bluehead wrasse (Thalassoma bifasciatum) from three reef sites off St. Croix (USVI) and performed two analyses. First, we compared each settler's larval traits to the size of its social group to determine whether larval traits influenced group-joining behaviour. Secondly, we observed foraging behaviour in a subset of grouped and solitary fish (n = 14) for 1-4 days post-settlement. We then collected the fish and tested whether larval traits influenced the proportion of time spent foraging. Body length at settlement, but not condition, affected group-joining behaviour; smaller fish were more likely to remain solitary or in smaller groups. However, both greater length and better condition were associated with greater proportions of time spent foraging over four consecutive days post-settlement. Larval traits carry over to affect post

  1. Does human pressure affect the community structure of surf zone fish in sandy beaches?

    NASA Astrophysics Data System (ADS)

    Costa, Leonardo Lopes; Landmann, Júlia G.; Gaelzer, Luiz R.; Zalmon, Ilana R.

    2017-01-01

    Intense tourism and human activities have resulted in habitat destruction in sandy beach ecosystems with negative impacts on the associated communities. To investigate whether urbanized beaches affect surf zone fish communities, fish and their benthic macrofaunal prey were collected during periods of low and high human pressure at two beaches on the Southeastern Brazilian coast. A BACI experimental design (Before-After-Control-Impact) was adapted for comparisons of tourism impact on fish community composition and structure in urbanized, intermediate and non-urbanized sectors of each beach. At the end of the summer season, we observed a significant reduction in fish richness, abundance, and diversity in the high tourist pressure areas. The negative association between visitors' abundance and the macrofaunal density suggests that urbanized beaches are avoided by surf zone fish due to higher human pressure and the reduction of food availability. Our results indicate that surf zone fish should be included in environmental impact studies in sandy beaches, including commercial species, e.g., the bluefish Pomatomus saltatrix. The comparative results from the less urbanized areas suggest that environmental zoning and visitation limits should be used as effective management and preservation strategies on beaches with high conservation potential.

  2. Relating fish health and reproductive metrics to contaminant bioaccumulation at the Tennessee Valley Authority Kingston coal ash spill site

    SciTech Connect

    Pracheil, Brenda M.; Marshall Adams, S.; Bevelhimer, Mark S.; Fortner, Allison M.; Greeley, Mark S.; Murphy, Cheryl A.; Mathews, Teresa J.; Peterson, Mark J.

    2016-05-06

    A 4.1 million m3 release of coal ash into the Emory and Clinch rivers in December 2008 at Tennessee Valley Authority s Kingston Fossil Plant has prompted a long-term, large-scale biological monitoring effort to determine if there are chronic effects of this spill on biota. Of concern in this spill were arsenic (As) and selenium (Se), heavy metal constituents of coal ash that can be toxic to fish and wildlife and also mercury (Hg): a legacy contaminant that can interact with Se in organisms. We used fish filet bioaccumulation data from Bluegill Lepomis macrochirus, Redear Lepomis microlophus, Largemouth Bass Micropterus salmoides and Channel Catfish Ictalurus punctatus and metrics of fish health including fish condition indices, blood chemistry parameters and liver histopathology data collected from 2009-2013 to determine whether tissue heavy metal burdens relate 1) to each other 2) to metrics of fish health (e.g., blood chemistry characteristics and liver histopathology) and condition, and 3) whether relationships between fish health characteristics and heavy metals are related to site and ash-exposure. We found that burdens of Se and As are generally related to each other between tissues, but burdens of Hg between tissues are not generally positively associated. Taking analyses together, there appears to be reductions in growth and sublethal liver and kidney dysfunction in Bluegill and Largemouth Bass as indicated by blood chemistry parameters (elevated blood protein, glucose, phosphorous, blood urea nitrogen and creatinine in ash-affected sites) and related to concentrations of As and Se. Seeing sub-lethal effects in these species of fish is interesting because Redear had the highest filet burdens of Se, but did not have biomarkers indicating disease or dysfunction. We conclude our study by highlighting the complexities inherent in multimetric fish health data and the need for continued monitoring to further untangle contaminant and fish health

  3. Relating fish health and reproductive metrics to contaminant bioaccumulation at the Tennessee Valley Authority Kingston coal ash spill site

    DOE PAGES

    Pracheil, Brenda M.; Marshall Adams, S.; Bevelhimer, Mark S.; ...

    2016-05-06

    A 4.1 million m3 release of coal ash into the Emory and Clinch rivers in December 2008 at Tennessee Valley Authority s Kingston Fossil Plant has prompted a long-term, large-scale biological monitoring effort to determine if there are chronic effects of this spill on biota. Of concern in this spill were arsenic (As) and selenium (Se), heavy metal constituents of coal ash that can be toxic to fish and wildlife and also mercury (Hg): a legacy contaminant that can interact with Se in organisms. We used fish filet bioaccumulation data from Bluegill Lepomis macrochirus, Redear Lepomis microlophus, Largemouth Bass Micropterusmore » salmoides and Channel Catfish Ictalurus punctatus and metrics of fish health including fish condition indices, blood chemistry parameters and liver histopathology data collected from 2009-2013 to determine whether tissue heavy metal burdens relate 1) to each other 2) to metrics of fish health (e.g., blood chemistry characteristics and liver histopathology) and condition, and 3) whether relationships between fish health characteristics and heavy metals are related to site and ash-exposure. We found that burdens of Se and As are generally related to each other between tissues, but burdens of Hg between tissues are not generally positively associated. Taking analyses together, there appears to be reductions in growth and sublethal liver and kidney dysfunction in Bluegill and Largemouth Bass as indicated by blood chemistry parameters (elevated blood protein, glucose, phosphorous, blood urea nitrogen and creatinine in ash-affected sites) and related to concentrations of As and Se. Seeing sub-lethal effects in these species of fish is interesting because Redear had the highest filet burdens of Se, but did not have biomarkers indicating disease or dysfunction. We conclude our study by highlighting the complexities inherent in multimetric fish health data and the need for continued monitoring to further untangle contaminant and fish health

  4. Female preference for males depends on reproductive physiology in the African cichlid fish Astatotilapia burtoni.

    PubMed

    Kidd, Michael R; O'Connell, Lauren A; Kidd, Celeste E; Chen, Christine W; Fontenot, Miles R; Williams, Sidney J; Hofmann, Hans A

    2013-01-01

    Mate choice is fundamental to sexual selection, yet little is known about underlying physiological mechanisms that influence female mating decisions. We investigated the endocrine underpinnings of female mate choice in the African cichlid Astatotilapia burtoni, a non-seasonal breeder. In addition to profiling behavioral and hormonal changes across the female reproductive cycle, we tested two hypotheses regarding possible factors influencing female mate choice. We first asked whether female mate choice is influenced by male visual and/or chemical cues. A. burtoni females were housed for one full reproductive cycle in the center of a dichotomous choice apparatus with a large (attractive) or small (unattractive) conspecific male on either side. Females associated mostly with small, less attractive males, but on the day of spawning reversed their preference to large, attractive males, with whom they mated almost exclusively, although this choice depended on the relative amount of androgens released into the water by small males. We next asked whether male behavior or androgen levels change in relation to the stimulus females' reproductive state. We found that stimulus male aggression decreased and reproductive displays increased as the day of spawning approached. Moreover male testosterone levels changed throughout the females' reproductive cycle, with larger males releasing more testosterone into the water than small males. Our data suggest that female association in a dichotomous choice assay is only indicative of the actual mate choice on the day of spawning. Furthermore, we show that male behavior and hormone levels are dependent on the reproductive state of conspecific females.

  5. Honey and honey-based sugars partially affect reproductive trade-offs in parasitoids exhibiting different life-history and reproductive strategies.

    PubMed

    Harvey, Jeffrey A; Essens, Tijl A; Las, Rutger A; van Veen, Cindy; Visser, Bertanne; Ellers, Jacintha; Heinen, Robin; Gols, Rieta

    2016-12-23

    Adult dietary regimes in insects may affect egg production, fecundity and ultimately fitness. This is especially relevant in parasitoid wasps where many species serve as important biological control agents of agricultural pests. Here, we tested the effect of honey and sugar diets on daily fecundity schedules, lifetime reproductive success and longevity in four species of parasitoid wasps when reared on their respective hosts. The parasitoid species were selected based on dichotomies in host usage strategies and reproductive traits. Gelis agilis and G. areator are idiobiont ecto-parasitoids that develop in non-growing hosts, feed on protein-rich host fluids to maximize reproduction as adults and produce small numbers of large eggs. Meteorus pulchricornis and Microplitis mediator are koinobiont endoparasitoids that develop inside the bodies of growing hosts, do not host-feed, and produce greater numbers of small eggs. Parasitoids were reared on diets of either pure honey (containing trace amounts of proteins), heated honey (with denatured proteins) and a honey-mimic containing sugars only. We hypothesized that the benefits of proteins in honey would enhance reproduction in the ectoparasitoids due to their high metabolic investment per egg, but not in the koinobionts. Pure honey diet resulted in higher lifetime fecundity in G. agilis compared with the honey-mimic, whereas in both koinobionts, reproductive success did not vary significantly with diet. Longevity was less affected by diet in all of the parasitoids, although there were variable trade-offs between host access and longevity in the four species. We argue that there are both trait-based and association-specific effects of supplementary nutrients in honey on reproductive investment and success in parasitoid wasps.

  6. [Reproduction and growth of the fish Lutjanus guttatus (Pisces: Lutjanidae) in the Gulf of Nicoya, Costa Rica].

    PubMed

    Rojas, Rosa L Soto; Mejía-Arana, Fernando; Palacios, J A; Hiramatsu, Kazuhito

    2009-01-01

    Reproduction and growth of the fish Lutjanus guttatus (Pisces: Lutjanidae) in the Gulf of Nicoya, Costa Rica. The fish Lutjanus guttatus is important in the fisheries of Golfo de Nicoya, Costa Rica where they are captured with varied gear mainly by the artisanal fleet. We measured specimens from the commercial catch of 2002-2006. Gonadal state was determined macroscopically and age with otoliths The total length-total weight relationship was y = 0.0236x(2.8153) and total length-eviscerated weight y = 0.0216x(2.8129). Simplified relationships were y = 0.0173x3 and y = 0.0162x3. There is year-round reproduction with peaks in March (dry season) and September (rainy season). Male-female sexual ratio was 1:1. The age-length key for the gulf shows availability until the 6 years of age. The von Bertalanffy growth curve is L(t) = 65,9 (1-e(-0.13(t+2,66))).

  7. Pollinator diversity affects plant reproduction and recruitment: the tradeoffs of generalization.

    PubMed

    Gómez, José M; Bosch, Jordi; Perfectti, Francisco; Fernández, Juande; Abdelaziz, Mohamed

    2007-09-01

    One outstanding and unsolved challenge in ecology and conservation biology is to understand how pollinator diversity affects plant performance. Here, we provide evidence of the functional role of pollination diversity in a plant species, Erysimum mediohispanicum (Brassicaceae). Pollinator abundance, richness and diversity as well as plant reproduction and recruitment were determined in eight plant populations. We found that E. mediohispanicum was generalized both at the regional and local (population) scale, since its flowers were visited by more than 100 species of insects with very different morphology, size and behaviour. However, populations differed in the degree of generalization. Generalization correlated with pollinator abundance and plant population size, but not with habitat, ungulate damage intensity, altitude or spatial location. More importantly, the degree of generalization had significant consequences for plant reproduction and recruitment. Plants from populations with intermediate generalization produced more seeds than plants from populations with low or high degrees of generalization. These differences were not the result of differences in number of flowers produced per plant. In addition, seedling emergence in a common garden was highest in plants from populations with intermediate degree of generalization. This outcome suggests the existence of an optimal level of generalizations even for generalized plant species.

  8. Factors affecting reproductive success in three entomophilous orchid species in Hungary.

    PubMed

    Vojtkó, Anna E; Sonkoly, Judit; Lukács, Balázs András; Molnár V, Attila

    2015-06-01

    The reproductive success of orchids is traditionally estimated by determining the fruit-set of individuals. Here, we investigated both the fruit and the seed production of three orchid species and the factors that may affect individual fruit-set, like pollination strategy, individual traits or the annual amount of precipitation. The species [Dactylorhiza sambucina (L.) Soó, Dactylorhiza majalis (Rchb.) P. F. Hunt & Summerhayes and Platanthera bifolia (L.) L. C. M. Richard] were studied in three consecutive years (2010-2012) in the Bükk Mountains, Hungary. All three species were proved to be non-autogamous by a bagging experiment. Data analyses showed significant differences between seed numbers but not between fruit-sets of species. There was no statistical difference in individual reproductive success between wet and dry years, however, the effect of the annual amount of precipitation is significant on the population level. Comparison of published fruit-set data revealed accordance with our results in P. bifolia, but not in D. sambucina and D. majalis. We assume that the surprisingly high fruit-set values of the two Dactylorhiza species may be due to the fact that the pollination crisis reported from Western European countries is not an actual problem in the Bükk Mountains, Hungary.

  9. COLLAPSE OF A FISH POPULATION FOLLOWING EXPOSURE TO A SYNTHETIC ESTROGEN

    EPA Science Inventory

    Municipal wastewaters are a complex mixture containing estrogens and estrogen mimics that are known to affect the reproductive health of wild fishes. Male fishes downstream of some wastewater outfalls produce vitellogenin (VTG) (a protein normally synthesized by females during oo...

  10. Gonadogenesis and annual reproductive cycles of an endangered cyprinid fish, the lake minnow Eupallasella percnurus (Pallas, 1814).

    PubMed

    Hliwa, Piotr; Król, Jarosław; Sikorska, Justyna; Wolnicki, Jacek; Dietrich, Grzegorz J; Kamiński, Rafał; Stabińska, Agnieszka; Ciereszko, Andrzej

    2017-01-01

    In this study, gonadogenesis, the effect of temperature (15, 20 and 25°C) on sex differentiation, and annual changes in the gonads of mature lake minnow Eupallasella percnurus (Pallas, 1814) were determined. The lake minnow was found to be a primary gonochoristic fish species, where gonads are formed directly in the ovaries or testes. The morphological differentiation of gonads was initiated 35days post hatch (DPH) when two types of gonadal anlages were visible: a pear-shaped gonad attached by a single mesentery string and a spindle-shaped gonad attached on both sides to the peritoneum. Gonadogenesis occurred faster in females than in males, with the first previtellogenic oocytes and ovarian lamellae being already observed in 45 DPH fish. In males, cytological differentiation occurred approximately 85 DPH, when the fish reached an average body weight of more than 400mg. No significant effect of rearing temperature on sex ratio in lake minnow juveniles was observed. The proportion of males and females was similar (close to 1:1) in all of the thermal-treated groups, although there were effects of temperature on the final sizes of fish. Histological examination of wild, mature lake minnow ovaries during the annual cycle (from May to February the following year) showed asynchronous oocyte maturation. The testes were characteristic of multi-batch spawning fish. Quantitative dominance of spermatids and mature spermatozoa in May was observed, while the presence of primary and secondary spermatocytes in all other periods was confirmed. These changes were also reflected in the seasonal variation in the gonado-somatic index in both sexes, with the highest mean values of 11.2% (females) and 4.0% (males) in May, which were found to be significantly different to all other periods. The data presented in this study provide an important contribution to our understanding of the biology and reproductive strategy of the endangered lake minnow.

  11. Landscape composition, patch size, and distance to edges: Interactions affecting duck reproductive success

    USGS Publications Warehouse

    Horn, David Joseph; Phillips, Michael L.; Koford, Rolf R.; Clark, William R.; Sovada, Marsha A.; Greenwood, Raymond J.

    2005-01-01

    Prairies and other North American grasslands, although highly fragmented, provide breeding habitat for a diverse array of species, including species of tremendous economic and ecological importance. Conservation and management of these species requires some understanding of how reproductive success is affected by edge effects, patch size, and characteristics of the landscape. We examined how differences in the percentage of grassland in the landscape influenced the relationships between the success of nests of upland-nesting ducks and (1) field size and (2) distance to nearest field and wetland edges. We collected data on study areas composed of 15–20% grassland and areas composed of 45–55% grassland in central North Dakota, USA during the 1996 and 1997 nesting seasons. Daily survival rates (DSRs) of duck nests were greater in study areas with 45–55% grassland than with 15–20% grassland. Within study areas, we detected a curvilinear relationship between DSR and field size: DSRs were highest in small and large fields and lowest in moderately sized fields. In study areas with 15–20% grassland, there was no relationship between probability of hatching and distance to nearest field edge, whereas in study areas with 45–55% grassland, there was a positive relationship between these two variables. Results of this study support the conclusion that both landscape composition and configuration affect reproductive success of ground-nesting birds. We are prompted to question conservation strategies that favor clustering moderately sized patches of nesting habitat within agricultural landscapes because our results show that such patches would have low nest success, most likely caused by predation. Understanding the pattern of nest success, and the predator–prey mechanisms that produce the pattern, will enable design of patch configurations that are most conducive to meeting conservation goals.

  12. Reproduction potentiated in nematodes (Caenorhabditis elegans) and guppy fish (Poecilia reticulata) by adding a synthetic peptide to their aqueous environment.

    PubMed

    Davies, Keith G; Zimmerman, Brian; Dudley, Ed; Newton, Russell P; Hart, John E

    2015-03-01

    Ambient exposure to a short synthetic peptide has enhanced fecundity (number of offspring) in invertebrates and vertebrates, ostensibly by disinhibiting reproduction. In separate experiments, nematodes (Caenorhabditis elegans) and guppy fish (Poecilia reticulata) were exposed via their aqueous environment to a dissolved synthetic hexamer (6mer) peptide, IEPVFT (EPL036), at a concentration of 1 μmol l(-1). In the case of the worms, peptide was added to their aqueous buffer daily throughout the experiment (14 days); for the guppies, peptide administration was on the first 15 alternate days in a 50 week experiment. Fecundity rose by 79% among the worms. The number of descendants of the treated guppies was more than four times that of controls by week 26 (103 versus 25, including 72 juveniles versus 6), with 15.4% more estimated biomass in the test tank in total (i.e. including founders). It was deduced that treated females bred earlier, at a smaller size, and had larger brood sizes. The total number of fish in the control tank had caught up by termination, but biomass continued to lag the test tank. There were no overt signs of toxicity among either the worms or the fish. Bioinformatics has been unilluminating in explaining these results in terms, for example, of mimicry of an endogenous regulator. A mass spectrometric campaign to identify a receptor, using murine brain for expediency, proved inconclusive. Molecular modelling in silico indicated unexpectedly that the hexamer EPL036 might be acting as an antagonist, to pro-fecundity effect; that is, as a blocker of an inhibitor. This suggests that there awaits discovery an evolutionarily conserved reproductive inhibitor and its (anti-fecundity) receptor.

  13. Evaluation of bioelectrical impedance analysis (BIA) to measure condition and energy allocated to reproduction in marine fishes

    NASA Astrophysics Data System (ADS)

    Fitzhugh, G. R.; Wuenschel, M. J.; McBride, R. S.

    2010-04-01

    Reliable estimates of fish energy density at specific times prior to spawning may provide suitable proxies for egg production, and thereby help to explain some of the observed annual variation in recruits per spawner. Our goal is to develop and test modifications of BIA technology to measure energy allocation to reproduction for a variety of marine fishes. To date, a newly developed measuring board and probe system stabilized readings, which was demonstrated by a significant reduction in the coefficients of variation for impedance measures. Total body water, wet and dry weights could be predicted with very good precision (r2 = 0.92-0.99) using BIA measures of reactance or resistance for a number of finfish species. While constituent relationships (e.g. body water- body mass functions) did not differ seasonally, we did find that BIA measures are sensitive to body composition changes related to the seasonal spawning cycle. In an examination of monthly samples of tilefish, phase angle decreased below 15° in post-spawning (regressed) females. Such a monthly trend, which suggests available energy had decreased following the spawning season, was not evident from other, more traditional measures of condition including body-muscle water content, Fulton's K or ordinal measures of fat deposition (such as mesenteric fat). These preliminary results show that BIA technology is a promising application for tracking and efficiently predicting energetic condition of marine fishes.

  14. Dietary CdSe/ZnS quantum dot exposure in estuarine fish: bioavailability, oxidative stress responses, reproduction, and maternal transfer.

    PubMed

    Blickley, T Michelle; Matson, Cole W; Vreeland, Wyatt N; Rittschof, Daniel; Di Giulio, Richard T; McClellan-Green, Patricia D

    2014-03-01

    Continued development, use, and disposal of quantum dots (QDs) ensure their entrance into aquatic environments where they could pose a risk to biological organisms as whole nanoparticles or as degraded metal constituents. Reproductive Fundulus heteroclitus were fed a control diet with lecithin, diets containing 1 or 10 μg of lecithin-encapsulated CdSe/ZnS QD/day, or a diet containing 5.9 μg CdCl2/day for 85 days. Cadmium concentrations in liver, intestine, and eggs were quantified with inductively coupled plasma mass spectrometry. In fish fed 10 μg QD/day, QDs or their degradation products traversed the intestinal epithelia and accumulated in the liver. Less than 0.01% of the QD's cadmium was retained in the liver or intestinal tissues. This compares to 0.9% and 0.5% of the cadmium in the intestine and liver, respectively of fish fed a CdCl2 diet. Cadmium was also detected in the eggs from parents fed 10 μg QD/day. No significant changes in hepatic total glutathione, lipid peroxidation, or expression of genes involved in metal metabolism or oxidative stress were observed. While QDs in the diet are minimally bioavailable, unusual levels of vitellogenin transcription in male fish as well as declining fecundity require further investigation to determine if endocrine disruption is of environmental concern.

  15. The first success of glass eel production in the world: basic biology on fish reproduction advances new applied technology in aquaculture.

    PubMed

    Kagawa, Hirohiko; Tanaka, Hideki; Ohta, Hiromi; Unuma, Tatsuya; Nomura, Kazuharu

    2005-04-01

    The eel has long been esteemed as an important food fish in the world, especially in Japan, and has been used as an experimental fish for many fields of fish physiology. However, the decreases in eel resources have been a serious concern in recent years. The catches of glass eels as seedlings for aquaculture have shown a long-term decrease in both Europe and East Asia. To increase eel resources, the development of techniques for artificial induction of maturation and spawning and rearing their larvae have been eagerly desired. Recent progress of reproductive physiology of fish, especially mechanisms of oocyte maturation and ovulation in female and of spermatozoa maturation in male, facilitate to establish techniques for hormonal induction of maturation and spawning in sexually immature eels. With persistent effort to development of rearing techniques of larvae, we have first succeeded to produce glass eel. These applied techniques are may contribute to understand the basic reproductive physiology of the eel.

  16. To Fish or Not to Fish: Factors at Multiple Scales Affecting Artisanal Fishers' Readiness to Exit a Declining Fishery

    PubMed Central

    Daw, Tim M.; Cinner, Joshua E.; McClanahan, Timothy R.; Brown, Katrina; Stead, Selina M.; Graham, Nicholas A. J.; Maina, Joseph

    2012-01-01

    Globally, fisheries are challenged by the combined impacts of overfishing, degradation of ecosystems and impacts of climate change, while fisheries livelihoods are further pressured by conservation policy imperatives. Fishers' adaptive responses to these pressures, such as exiting from a fishery to pursue alternative livelihoods, determine their own vulnerability, as well as the potential for reducing fishing effort and sustaining fisheries. The willingness and ability to make particular adaptations in response to change, such as exiting from a declining fishery, is influenced by economic, cultural and institutional factors operating at scales from individual fishers to national economies. Previous studies of exit from fisheries at single or few sites, offer limited insight into the relative importance of individual and larger-scale social and economic factors. We asked 599 fishers how they would respond to hypothetical scenarios of catch declines in 28 sites in five western Indian Ocean countries. We investigated how socioeconomic variables at the individual-, household- and site-scale affected whether they would exit fisheries. Site-level factors had the greatest influence on readiness to exit, but these relationships were contrary to common predictions. Specifically, higher levels of infrastructure development and economic vitality - expected to promote exit from fisheries - were associated with less readiness to exit. This may be due to site level histories of exit from fisheries, greater specialisation of fishing households, or higher rewards from fishing in more economically developed sites due to technology, market access, catch value and government subsidies. At the individual and household scale, fishers from households with more livelihood activities, and fishers with lower catch value were more willing to exit. These results demonstrate empirically how adaptive responses to change are influenced by factors at multiple scales, and highlight the importance

  17. Particularities of reproduction and oogenesis in teleost fish compared to mammals.

    PubMed

    Jalabert, Bernard

    2005-01-01

    Compared to mammals, teleost reproduction presents many original features. Reproductive strategies of species are diversified into numerous adaptations to a large variety of aquatic environments. This diversity may concern sexuality, spawning and parental behaviour, sensitivity to environmental factors, and specific features of gametogenesis such as the duration of vitellogenesis, and egg morphology. Sexuality presents a variety of natural modalities, from gonochorism to hermaphrodism. The absence of definitive arrest of body growth in the adult of most species gives a particular interest to the practical control of growth-reproduction interactions. Vitellogenesis, which represents an important metabolic effort for the maternal organism, involves the synthesis of vitellogenin, a specific glycolipo-phosphoprotein produced in the liver under estradiol stimulation, and its incorporation into oocytes by a receptor mediated process. Both estradiol synthesis in follicle cells and vtg uptake by vitellogenic follicles appear to be mainly controlled by FSH. Oocyte maturation is directly triggered by a progestin, or MIS (maturation inducing steroid) synthesised in follicle cells mainly under LH control, and acting through the non-genomic activation of a membrane receptor. Practical applications of some of these particularities result mainly from the external character of the fertilisation process and of embryonic development, which allows manipulating respectively egg chromosome stocks and sex differentiation. Moreover, the sensitivity of sex differentiation to exogenous factors favours the development of practical methods to control the sex of farmed populations. Finally, the sensitivity of reproductive mechanisms to xenobiotics has led to various kinds of bioassays for putative pollutants.

  18. Sex in troubled waters: Widespread agricultural contaminant disrupts reproductive behaviour in fish.

    PubMed

    Bertram, Michael G; Saaristo, Minna; Baumgartner, John B; Johnstone, Christopher P; Allinson, Mayumi; Allinson, Graeme; Wong, Bob B M

    2015-04-01

    Chemical pollution is a pervasive and insidious agent of environmental change. One class of chemical pollutant threatening ecosystems globally is the endocrine disrupting chemicals (EDCs). The capacity of EDCs to disrupt development and reproduction is well established, but their effects on behaviour have received far less attention. Here, we investigate the impact of a widespread androgenic EDC on reproductive behaviour in the guppy, Poecilia reticulata. We found that short-term exposure of male guppies to an environmentally relevant concentration of 17β-trenbolone-a common environmental pollutant associated with livestock production-influenced the amount of male courtship and forced copulatory behaviour (sneaking) performed toward females, as well as the receptivity of females toward exposed males. Exposure to 17β-trenbolone was also associated with greater male mass. However, no effect of female exposure to 17β-trenbolone was detected on female reproductive behaviour, indicating sex-specific vulnerability at this dosage. Our study is the first to show altered male reproductive behaviour following exposure to an environmentally realistic concentration of 17β-trenbolone, demonstrating the possibility of widespread disruption of mating systems of aquatic organisms by common agricultural contaminants.

  19. Intermittent fasting during winter and spring affects body composition and reproduction of a migratory duck

    USGS Publications Warehouse

    Barboza, P.S.; Jorde, D.G.

    2002-01-01

    We compared food intake, body mass and body composition of male and female black ducks (Anas rubripes) during winter (January-March). Birds were fed the same complete diet ad libitum on consecutive days each week without fasting (control; nine male; nine female) or with either short fasts (2 day.week-1; nine male; nine female), or long fasts (4 day.week-1; eleven male; twelve female). We continued treatments through spring (March-May) to measure the effect of intermittent fasts on body mass and egg production. Daily food intake of fasted birds was up to four times that of unfasted birds. Weekly food intake of males was similar among treatments (364 g.kg-1.week-1) but fasted females consumed more than unfasted females in January (363 g.kg-1.week-1 vs. 225 g.kg-1.week-1). Although both sexes lost 10-14% body mass, fasted females lost less mass and lipid than unfasted females during winter. Total body nitrogen was conserved over winter in both sexes even though the heart and spleen lost mass while the reproductive tract and liver gained mass. Intermittent fasting increased liver, intestinal tissue and digesta mass of females but not of males. Fasting delayed egg production in spring but did not affect size, fertility or hatching of the clutch. Females on long fasts were still heavier than controls after laying eggs. Thus black ducks combine flexibility of food intake with plasticity of digestive tract, liver and adipose tissue when food supply is interrupted during winter. Females modulate body mass for survival and defer reproduction when food supply is interrupted in spring.

  20. Occurrence of perchloroethylene in surface water and fish in a river ecosystem affected by groundwater contamination.

    PubMed

    Wittlingerová, Zdena; Macháčková, Jiřina; Petruželková, Anna; Zimová, Magdalena

    2016-03-01

    Long-term monitoring of the content of perchloroethylene (PCE) in a river ecosystem affected by groundwater contamination was performed at a site in the Czech Republic. The quality of surface water was monitored quarterly between 1994 and 2013, and fish were collected from the affected ecosystem to analyse the content of PCE in their tissue in 1998, 2011 and 2012. Concentrations of PCE (9-140 μg/kg) in the tissue of fish collected from the contaminated part of the river were elevated compared to the part of the river unaffected by the contamination (ND to 5 μg/kg PCE). The quality of surface water has improved as a result of groundwater remediation during the evaluated period. Before the remedial action, PCE concentrations ranged from 30 to 95 μg/L (1994-1997). Following commencement of remedial activities in September 1997, a decrease in the content of PCE in the surface water to 7.3 μg/L (1998) and further to 1 μg/L (2011) and 1.1 μg/L (2012) led to a progressive decrease in the average concentration of PCE in the fish muscle tissue from 79 μg/kg (1998) to 24 (2011) and 30 μg/kg (2012), respectively. It was determined that the bioconcentration of PCE does not have a linear dependence because the decrease in contamination in the fish muscle tissue is not directly proportional to the decrease in contamination in the river water. The observed average bioconcentration factors were 24 and 28 for the lower concentrations of PCE and 11 for the higher concentrations of PCE in the river. In terms of age, length and weight of the collected fish, weight had the greatest significance for bioconcentration, followed by the length, with age being evaluated as a less significant factor.

  1. AOP description: Androgen receptor agonism leading to reproductive dysfunction (in fish)

    EPA Science Inventory

    This adverse outcome pathway details the linkage between binding and activation of androgen receptor as a nuclear transcription factor in females and the adverse effect of reduced cumulative fecundity in repeat-spawning fish species. Cumulative fecundity is the most apical endpoi...

  2. Reproductive Strategies of the Insidious Fish Ectoparasite, Neobenedenia sp. (Capsalidae: Monogenea)

    PubMed Central

    Dinh Hoai, Truong; Hutson, Kate S.

    2014-01-01

    Fish monogeneans are lethal parasites in aquaculture. We provide the first experimental evidence that a notorious fish monogenean, Neobenedenia sp., can produce viable eggs in isolation for three consecutive generations. We infected individual, isolated, farmed barramundi, Lates calcarifer (Bloch) with a single oncomiracidium (larva) of the hermaphroditic monogenean Neobenedenia sp. Isolated parasites reached sexual maturity at day 10 post-hatch (24°C, 35‰) and laid ∼3,300 embryonated eggs over 17 days. Egg production rapidly increased following sexually maturity on day 10 (58±15 eggs) and peaked on day 15 (496±68 eggs) before gradually decreasing. Neobenedenia sp. exhibited egg laying and egg hatching rhythms. Parasites laid eggs continuously, but egg production increased in periods of darkness (64.3%), while the majority of oncomiracidia (81%) emerged from eggs in the first three hours of light. Eggs laid by isolated ‘parent’ parasites hatched and individual emerging oncomiracidia were used to infect more individual, isolated fish, with three consecutive, isolated, parasite generations (F1, F2 and F3) raised in the laboratory. Infection success and egg hatching success did not differ between generations. Our data show that one parasite, in the absence of a mate, presents a severe threat to captive fish populations. PMID:25264931

  3. Reproductive strategies of the insidious fish ectoparasite, Neobenedenia sp. (Capsalidae: Monogenea).

    PubMed

    Dinh Hoai, Truong; Hutson, Kate S

    2014-01-01

    Fish monogeneans are lethal parasites in aquaculture. We provide the first experimental evidence that a notorious fish monogenean, Neobenedenia sp., can produce viable eggs in isolation for three consecutive generations. We infected individual, isolated, farmed barramundi, Lates calcarifer (Bloch) with a single oncomiracidium (larva) of the hermaphroditic monogenean Neobenedenia sp.. Isolated parasites reached sexual maturity at day 10 post-hatch (24°C, 35‰) and laid ∼3,300 embryonated eggs over 17 days [corrected]. Egg production rapidly increased following sexually maturity on day 10 (58±15 eggs) and peaked on day 15 (496±68 eggs) before gradually decreasing. Neobenedenia sp. exhibited egg laying and egg hatching rhythms. Parasites laid eggs continuously, but egg production increased in periods of darkness (64.3%), while the majority of oncomiracidia (81%) emerged from eggs in the first three hours of light. Eggs laid by isolated 'parent' parasites hatched and individual emerging oncomiracidia were used to infect more individual, isolated fish, with three consecutive, isolated, parasite generations (F1, F2 and F3) raised in the laboratory. Infection success and egg hatching success did not differ between generations. Our data show that one parasite, in the absence of a mate, presents a severe threat to captive fish populations.

  4. CUNNER(TAUTOGOLABRUS ADSPERSUS) AS A MODEL FISH FOR REPRODUCTIVE STUDIES IN THE LABORATORY

    EPA Science Inventory

    Cunner (Tautogolabrus adspersus) are being studied at our laboratory as a model species to determine the effects of endocrine disrupting chemicals (EDCs) on estuarine fish populations. Cunner was selected because this species is common in estuarine areas, is easily obtainable, an...

  5. MHC genes and parasitism in Carassius gibelio, a diploid-triploid fish species with dual reproduction strategies

    PubMed Central

    2013-01-01

    Background The gibel carp is a fish species with dual reproduction modes, gynogenesis and sexual reproduction, coexisting in mixed diploid-polyploid populations. Following the Red Queen (RQ) assumption, asexual organisms are, due to their low genetic diversity, targets for parasite adaptation. Because MHC polymorphism is maintained by selection from parasites and sexual selection, MHC genes are considered as a suitable candidate for testing the RQ hypothesis. In this study, we investigated MHC variability and the selection pressure acting on MHC genes in sexual diploids and asexual triploids. In addition, we tested whether the asexual form of gibel carp suffers from higher parasite loads than the sexual form. Results At the population level, genotype and allelic diversity of MHC were reduced in gynogenetic triploids when compared to sexual diploids. Different patterns in positively selected sites (PSS) between gynogens and sexual gibel carp were also found. A weak difference in parasite species richness was found between sexual fish and gynogens. However, two common clones of gynogens were significantly more parasitized than sexual diploids or other gynogens with rare MHC genotypes. At the individual level, the higher number of alleles was not associated with higher parasitism in either sexual diploids or gynogens. Conclusions The differences in MHC diversity between gynogenetic triploids and sexual diploids are in accordance with the hypothesis of sexually-mediated selection increasing MHC diversity and fulfil a prerequisite of the Red Queen hypothesis. The different patterns in PSS between gynogens and sexual gibel carp also suggest the potential role of sexual selection and supports parasite-mediated selection maintaining MHC diversity. We showed that the most common MHC genotypes of gynogenetic triploids are the target of parasite selection. Our results suggest that the MHC genotype in gibel carp is more important than allelic number for immunocompetence. PMID

  6. Spatial and temporal patterns of larval dispersal in a coral-reef fish metapopulation: evidence of variable reproductive success.

    PubMed

    Pusack, Timothy J; Christie, Mark R; Johnson, Darren W; Stallings, Christopher D; Hixon, Mark A

    2014-07-01

    Many marine organisms can be transported hundreds of kilometres during their pelagic larval stage, yet little is known about spatial and temporal patterns of larval dispersal. Although traditional population-genetic tools can be applied to infer movement of larvae on an evolutionary timescale, large effective population sizes and high rates of gene flow present serious challenges to documenting dispersal patterns over shorter, ecologically relevant, timescales. Here, we address these challenges by combining direct parentage analysis and indirect genetic analyses over a 4-year period to document spatial and temporal patterns of larval dispersal in a common coral-reef fish: the bicolour damselfish (Stegastes partitus). At four island locations surrounding Exuma Sound, Bahamas, including a long-established marine reserve, we collected 3278 individuals and genotyped them at 10 microsatellite loci. Using Bayesian parentage analysis, we identified eight parent-offspring pairs, thereby directly documenting dispersal distances ranging from 0 km (i.e., self-recruitment) to 129 km (i.e., larval connectivity). Despite documenting substantial dispersal and gene flow between islands, we observed more self-recruitment events than expected if the larvae were drawn from a common, well-mixed pool (i.e., a completely open population). Additionally, we detected both spatial and temporal variation in signatures of sweepstakes and Wahlund effects. The high variance in reproductive success (i.e., 'sweepstakes') we observed may be influenced by seasonal mesoscale gyres present in the Exuma Sound, which play a prominent role in shaping local oceanographic patterns. This study documents the complex nature of larval dispersal in a coral-reef fish, and highlights the importance of sampling multiple cohorts and coupling both direct and indirect genetic methods in order disentangle patterns of dispersal, gene flow and variable reproductive success.

  7. Fish multigeneration test with preliminary short-term reproduction assay for estrone using Japanese medaka (Oryzias latipes).

    PubMed

    Nakamura, Ataru; Tamura, Ikumi; Takanobu, Hitomi; Yamamuro, Masumi; Iguchi, Taisen; Tatarazako, Norihisa

    2015-01-01

    The most potent chemicals potentially causing adverse effects on fish species are estrogens in human waste.Sewage is a source of these estrogens and it is difficult to reduce. In particular, although the bioactivity of estrone is estimated to be about half of that of estradiol, multiple studies report that more than 100 ng l(–1) of estrone can be detected in urban rivers, including discharges from sewage treatment works; approximately two times as high as estradiol. Few studies have been conducted to investigate the long-term effects of estrone on wildlife; therefore, we conducted fish multigeneration test using Japanese medaka (Oryzias latipes). Medaka were exposed to estrone for 27 weeks across three generations in environmentally relevant concentrations, being 5.74, 11.4, 24.0, 47.1 and 91.4 ng l(–1). No effects on reproduction were observed in the first generation; however, a decline in egg production and fertility was observed in the second generation exposed to 91.4 ng l(–1) estrone, which is lower than some known environmental concentrations in urban environments. Furthermore, histopathological abnormalities were observed in the third generation exposed to both 47.1 and 91.4 ng l(–1), suggesting that estrone possibly exerts severe effects on the third or later generations. However, appearances of testis–ova were observed in the second and third generation they were not consistent with actual effects on reproduction, notwithstanding the testis-ovais regarded as the key evidence for endocrine disruption. Accordingly, we consider that qualitative measurement of abnormalities using histopathological observations is required for appropriate evaluation of endocrine disruption.

  8. High intake of fatty fish, but not of lean fish, affects serum concentrations of TAG and HDL-cholesterol in healthy, normal-weight adults: a randomised trial.

    PubMed

    Hagen, Ingrid V; Helland, Anita; Bratlie, Marianne; Brokstad, Karl A; Rosenlund, Grethe; Sveier, Harald; Mellgren, Gunnar; Gudbrandsen, Oddrun A

    2016-08-01

    The aim of the present study was to examine whether high intake of lean or fatty fish (cod and farmed salmon, respectively) by healthy, normal-weight adults would affect risk factors of type 2 diabetes and CVD when compared with lean meat (chicken). More knowledge is needed concerning the potential health effects of high fish intake (>300 g/week) in normal-weight adults. In this randomised clinical trial, thirty-eight young, healthy, normal-weight participants consumed 750 g/week of lean or fatty fish or lean meat (as control) for 4 weeks at dinner according to provided recipes to ensure similar ways of preparations and choices of side dishes between the groups. Energy and macronutrient intakes at baseline and end point were similar in all groups, and there were no changes in energy and macronutrient intakes within any of the groups during the course of the study. High intake of fatty fish, but not lean fish, significantly reduced TAG and increased HDL-cholesterol concentrations in fasting serum when compared with lean meat intake. When compared with lean fish intake, fatty fish intake increased serum HDL-cholesterol. No differences were observed between lean fish, fatty fish and lean meat groups regarding fasting and postprandial glucose regulation. These findings suggest that high intake of fatty fish, but not of lean fish, could beneficially affect serum concentrations of TAG and HDL-cholesterol, which are CVD risk factors, in healthy, normal-weight adults, when compared with high intake of lean meat.

  9. A novel framework for interpretation of data from the fish short-term reproduction assay (FSTRA) for the detection of endocrine-disrupting chemicals

    EPA Science Inventory

    The fish short term reproduction assay (FSTRA) is a key component of the USEPA endocrine disruptor screening program (EDSP). The FSTRA considers several mechanistic and apical responses in fathead minnows (Pimephales promelas) to determine whether an unknown chemical is likely t...

  10. A novel framework for interpretation of data from the fish short-term reproduction assay (FSTRA) for the detection of endocrined-disrupting chemicals

    EPA Science Inventory

    The fish short term reproduction assay (FSTRA) is a key component of the USEPA endocrine disruptor screening program (EDSP). The FSTRA considers several mechanistic and apical responses in fathead minnows (Pimephales promelas) to determine whether an unknown chemical is likely to...

  11. A novel framework for interpretation of data from the fish short-term reproduction assay (FSTRA) for the detection of endocrine-disrupting chemicals (poster)

    EPA Science Inventory

    The fish short term reproduction assay (FSTRA) is a key component of the USEPA endocrine disruptor screening program (EDSP). The FSTRA considers several mechanistic and apical responses in fathead minnows (Pimephales promelas) to determine whether an unknown chemical is likely to...

  12. Multiple Mating and Reproductive Skew in Parental and Introgressed Females of the Live-Bearing Fish Xiphophorus Birchmanni

    PubMed Central

    Passow, Courtney N.; Delclos, Pablo J.; Kindsvater, Holly K.; Jones, Adam G.; Rosenthal, Gil G.

    2015-01-01

    Just as mating patterns can promote speciation or hybridization, the presence of hybridization can shape mating patterns within a population. In this study, we characterized patterns of multiple mating and reproductive skew in a naturally hybridizing swordtail fish species, Xiphophorus birchmanni. We quantified multiple mating using microsatellite markers to genotype embryos from 43 females collected from 2 wild populations. We also used a suite of single-nucleotide polymorphism markers to categorize females and their inferred mates as either parental X. birchmanni or as introgressed individuals, which carried alleles from a sister species, X. malinche. We found that parental and introgressed X. birchmanni females mated multiply with both parental and introgressed males. We found no difference in mating patterns or reproductive skew between parental and introgressed X. birchmanni females. However, nonintrogressed X. birchmanni males mated more often with large, fecund females. These females also had the greatest levels of skew in fertilization success of males. Thus, our results show that X. birchmanni has a polygynandrous mating system and that introgression of X. malinche alleles has only subtle effects on mating patterns in this species. PMID:25433083

  13. Multiple mating and reproductive skew in parental and introgressed females of the live-bearing fish Xiphophorus birchmanni.

    PubMed

    Paczolt, Kimberly A; Passow, Courtney N; Delclos, Pablo J; Kindsvater, Holly K; Jones, Adam G; Rosenthal, Gil G

    2015-01-01

    Just as mating patterns can promote speciation or hybridization, the presence of hybridization can shape mating patterns within a population. In this study, we characterized patterns of multiple mating and reproductive skew in a naturally hybridizing swordtail fish species, Xiphophorus birchmanni. We quantified multiple mating using microsatellite markers to genotype embryos from 43 females collected from 2 wild populations. We also used a suite of single-nucleotide polymorphism markers to categorize females and their inferred mates as either parental X. birchmanni or as introgressed individuals, which carried alleles from a sister species, X. malinche. We found that parental and introgressed X. birchmanni females mated multiply with both parental and introgressed males. We found no difference in mating patterns or reproductive skew between parental and introgressed X. birchmanni females. However, nonintrogressed X. birchmanni males mated more often with large, fecund females. These females also had the greatest levels of skew in fertilization success of males. Thus, our results show that X. birchmanni has a polygynandrous mating system and that introgression of X. malinche alleles has only subtle effects on mating patterns in this species.

  14. FiRe: Reproductive disorders in Baltic fish - a presentation of a new Swedish EPA research program

    SciTech Connect

    Bengtsson, B.E.

    1994-12-31

    In 1974 a considerable increase in mortality of newly hatched fry of salmon (Salmo salar) was discovered at one of the Swedish hatcheries at the Baltic Sea coast. A series of symptoms was identified towards the end of the yolk sac resorption stage and was followed by a rapidly occurring and often high mortality shortly after the first symptoms were seen. The condition was given the name M74, where M depicts ``Miljoe``, i.e. ``Environment`` in Swedish and 74 stands for the first year of official registration, i.e. 1974. Since then the mortality in M74 has fluctuated considerably, but has increased n recent years. In 1992, M74 caused mortalities of up to 90% in newly hatched fry. In 1993 the situation was considered very serious and the number of surviving fry was insufficient to produce the stipulated number of compensation salmon for some Swedish rivers. The similarity with documented reproductive disturbances in salmonids in the Great Lakes is striking and also supports a possible connection to environmental pollution. However, hard data to support this theory are still lacking. With the present level of knowledge the research project is attempting to clarify the extent of fish reproduction disturbances in the Baltic Sea, the reasons and, if possible, to suggest how to mitigate the problem. Multinational research cooperation will be encouraged.

  15. Altered expression of the bZIP transcription factor DRINK ME affects growth and reproductive development in Arabidopsis thaliana.

    PubMed

    Lozano-Sotomayor, Paulina; Chávez Montes, Ricardo A; Silvestre-Vañó, Marina; Herrera-Ubaldo, Humberto; Greco, Raffaella; Pablo-Villa, Jeanneth; Galliani, Bianca M; Diaz-Ramirez, David; Weemen, Mieke; Boutilier, Kim; Pereira, Andy; Colombo, Lucia; Madueño, Francisco; Marsch-Martínez, Nayelli; de Folter, Stefan

    2016-11-01

    Here we describe an uncharacterized gene that negatively influences Arabidopsis growth and reproductive development. DRINK ME (DKM; bZIP30) is a member of the bZIP transcription factor family, and is expressed in meristematic tissues such as the inflorescence meristem (IM), floral meristem (FM), and carpel margin meristem (CMM). Altered DKM expression affects meristematic tissues and reproductive organ development, including the gynoecium, which is the female reproductive structure and is determinant for fertility and sexual reproduction. A microarray analysis indicates that DKM overexpression affects the expression of cell cycle, cell wall, organ initiation, cell elongation, hormone homeostasis, and meristem activity genes. Furthermore, DKM can interact in yeast and in planta with proteins involved in shoot apical meristem maintenance such as WUSCHEL, KNAT1/BP, KNAT2 and JAIBA, and with proteins involved in medial tissue development in the gynoecium such as HECATE, BELL1 and NGATHA1. Taken together, our results highlight the relevance of DKM as a negative modulator of Arabidopsis growth and reproductive development.

  16. Reproductive Potential of Salmon Spawning Substrates Inferred from Grain Size and Fish Length

    NASA Astrophysics Data System (ADS)

    Riebe, C. S.; Sklar, L. S.; Overstreet, B. T.; Wooster, J. K.; Bellugi, D. G.

    2014-12-01

    The river restoration industry spends millions of dollars every year on improving salmon spawning in riverbeds where sediment is too big for fish to move and thus use during redd building. However, few studies have addressed the question of how big is too big in salmon spawning substrates. Hence managers have had little quantitative basis for gauging the amount of spawning habitat in coarse-bedded rivers. Moreover, the scientific framework has remained weak for restoration projects that seek to improve spawning conditions. To overcome these limitations, we developed a physically based, field-calibrated model for the fraction of the bed that is fine-grained enough to support spawning by fish of a given size. Model inputs are fish length and easy-to-measure indices of bed-surface grain size. Model outputs include the number of redds and eggs the substrate can accommodate when flow depth, temperature, and other environmental factors are not limiting. The mechanistic framework of the model captures the biophysical limits on sediment movement and the space limitations on redd building and egg deposition in riverbeds. We explored the parameter space of the model and found a previously unrecognized tradeoff in salmon size: bigger fish can move larger sediment and thus use more riverbed area for spawning; they also tend to have higher fecundity, and so can deposit more eggs per redd; however, because redd area increases with fish length, the number of eggs a substrate can accommodate is highest for moderate-sized fish. One implication of this tradeoff is that differences in grain size may help regulate river-to-river differences in salmon size. Thus, our model suggests that population diversity and, by extension, species resilience are linked to lithologic, geomorphic, and climatic factors that determine grain size in rivers. We cast the model into easy-to-use look-up tables, charts, and computer applications, including a JavaScript app that works on tablets and mobile

  17. An evaluation of fish early life stage tests for predicting reproductive and longer-term toxicity from plant protection product active substances.

    PubMed

    Wheeler, James R; Maynard, Samuel K; Crane, Mark

    2014-08-01

    The chronic toxicity of chemicals to fish is routinely assessed by using fish early life stage (ELS) test results. Fish full life cycle (FLC) tests are generally required only when toxicity, bioaccumulation, and persistence triggers are met or when there is a suspicion of potential endocrine-disrupting properties. This regulatory approach is based on a relationship between the results of fish ELS and FLC studies first established more than 35 yrs ago. Recently, this relationship has been challenged by some regulatory authorities, and it has been recommended that more substances should undergo FLC testing. In addition, a project proposal has been submitted to the Organisation for Economic Cooperation and Development (OECD) to develop a fish partial life cycle (PLC) test including a reproductive assessment. Both FLC and PLC tests are animal- and resource-intensive and technically challenging and should therefore be undertaken only if there is clear evidence that they are necessary for coming to a regulatory decision. The present study reports on an analysis of a database of paired fish ELS and FLC endpoints for plant protection product active substances from European Union draft assessment reports and the US Environmental Protection Agency Office of Pesticide Programs Pesticide Ecotoxicity Database. Analysis of this database shows a clear relationship between ELS and FLC responses, with similar median sensitivity across substances when no-observed-effect concentrations (NOECs) are compared. There was also no indication that classification of a substance as a mammalian reproductive toxicant leads to more sensitive effects in fish FLC tests than in ELS tests. Indeed, the response of the ELS tests was generally more sensitive than the most sensitive reproduction NOEC from a FLC test. This analysis indicates that current testing strategies and guidelines are fit for purpose and that there is no need for fish full or partial life cycle tests for most plant protection

  18. Saccular-specific hair cell addition correlates with reproductive state-dependent changes in the auditory saccular sensitivity of a vocal fish

    PubMed Central

    Coffin, Allison B.; Mohr, Robert A.; Sisneros, Joseph A.

    2012-01-01

    The plainfin midshipman fish, Porichthys notatus, is a seasonal breeding teleost fish for which vocal-acoustic communication is essential for its reproductive success. Female midshipman use the saccule as the primary end organ for hearing to detect and locate “singing” males that produce multiharmonic advertisement calls during the summer breeding season. Previous work showed that female auditory sensitivity changes seasonally with reproductive state; summer reproductive females become better suited than winter nonreproductive females to detect and encode the dominant higher harmonic components in the male’s advertisement call, which are potentially critical for mate selection and localization. Here, we test the hypothesis that these seasonal changes in female auditory sensitivity are concurrent with seasonal increases in saccular hair cell receptors. We show that there is increased hair cell density in reproductive females and that this increase is not dependent on body size since similar changes in hair cell density were not found in the other inner ear end organs. We also observed an increase in the number of small, potentially immature saccular hair bundles in reproductive females. The seasonal increase in saccular hair cell density and smaller hair bundles in reproductive females was paralleled by a dramatic increase in the magnitude of the evoked saccular potentials and a corresponding decrease in the auditory thresholds recorded from the saccule. This demonstration of correlated seasonal plasticity of hair cell addition and auditory sensitivity may in part facilitate the adaptive auditory plasticity of this species to enhance mate detection and localization during breeding. PMID:22279221

  19. Reproductive health concerns in six conflict-affected areas of Sri Lanka.

    PubMed

    Kottegoda, Sepali; Samuel, Kumudini; Emmanuel, Sarala

    2008-05-01

    This article draws on a study conducted by the Women and Media Collective between 2004 and 2005 to highlight some of the reproductive health concerns of women from Sinhalese, Tamil and Muslim ethnic groups, living in situations of conflict in Sri Lanka. The study focussed on women from six conflict-affected areas in the north and east of the country: Jaffna (Northern Province), Mannar and Puttalam (North-Western Province), Polonnaruwa (North-Central Province), Batticaloa and Ampara (Eastern Province). Higher levels of poverty, higher rates of school drop-out, low pay and precarious access to work, mainly in the informal sector, higher rates of early marriage, pregnancy and home births, higher levels of maternal mortality and lower levels of contraceptive use were found. Economic, social and physical insecurity were key to these phenomena. Physically and psychologically, women were at high risk of sexual and physical violence, mainly from their partners/spouses but also from family members, often related to dowry. The article brings out the voices of women whose lives have been overshadowed by conflict and displacement, and the nature of structural barriers that impede their right to health care services, to make informed decisions about their lives and to live free of familial violence.

  20. An insulin-like signaling pathway affects both longevity and reproduction in Caenorhabditis elegans.

    PubMed Central

    Tissenbaum, H A; Ruvkun, G

    1998-01-01

    Mutations in daf-2 and age-1 cause a dramatic increase in longevity as well as developmental arrest at the dauer diapause stage in Caenorhabditis elegans. daf-2 and age-1 encode components of an insulin-like signaling pathway. Both daf-2 and age-1 act at a similar point in the genetic epistasis pathway for dauer arrest and longevity and regulate the activity of the daf-16 gene. Mutations in daf-16 cause a dauer-defective phenotype and are epistatic to the diapause arrest and life span extension phenotypes of daf-2 and age-1 mutants. Here we show that mutations in this pathway also affect fertility and embryonic development. Weak daf-2 alleles, and maternally rescued age-1 alleles that cause life span extension but do not arrest at the dauer stage, also reduce fertility and viability. We find that age-1(hx546) has reduced both maternal and zygotic age-1 activity. daf-16 mutations suppress all of the daf-2 and age-1 phenotypes, including dauer arrest, life span extension, reduced fertility, and viability defects. These data show that insulin signaling, mediated by DAF-2 through the AGE-1 phosphatidylinositol-3-OH kinase, regulates reproduction and embryonic development, as well as dauer diapause and life span, and that DAF-16 transduces these signals. The regulation of fertility, life span, and metabolism by an insulin-like signaling pathway is similar to the endocrine regulation of metabolism and fertility by mammalian insulin signaling. PMID:9504918

  1. Offspring size at weaning affects survival to recruitment and reproductive performance of primiparous gray seals

    PubMed Central

    Bowen, William D; den Heyer, Cornelia E; McMillan, Jim I; Iverson, Sara J

    2015-01-01

    Offspring size affects survival and subsequent reproduction in many organisms. However, studies of offspring size in large mammals are often limited to effects on juveniles because of the difficulty of following individuals to maturity. We used data from a long-term study of individually marked gray seals (Halichoerus grypus; Fabricius, 1791) to test the hypothesis that larger offspring have higher survival to recruitment and are larger and more successful primiparous mothers than smaller offspring. Between 1998 and 2002, 1182 newly weaned female pups were branded with unique permanent marks on Sable Island, Canada. Each year through 2012, all branded females returning to the breeding colony were identified in weekly censuses and a subset were captured and measured. Females that survived were significantly longer offspring than those not sighted, indicating size-selective mortality between weaning and recruitment. The probability of female survival to recruitment varied among cohorts and increased nonlinearly with body mass at weaning. Beyond 51.5 kg (mean population weaning mass) weaning mass did not influence the probability of survival. The probability of female survival to recruitment increased monotonically with body length at weaning. Body length at primiparity was positively related to her body length and mass at weaning. Three-day postpartum mass (proxy for birth mass) of firstborn pups was also positively related to body length of females when they were weaned. However, females that were longer or heavier when they were weaned did not wean heavier firstborn offspring. PMID:25897381

  2. No evidence for external genital morphology affecting cryptic female choice and reproductive isolation in Drosophila.

    PubMed

    LeVasseur-Viens, Hélène; Polak, Michal; Moehring, Amanda J

    2015-07-01

    Genitalia are one of the most rapidly diverging morphological features in animals. The evolution of genital morphology is proposed to be driven by sexual selection via cryptic female choice, whereby a female selectively uptakes and uses a particular male's sperm on the basis of male genital morphology. The resulting shifts in genital morphology within a species can lead to divergence in genitalia between species, and consequently to reproductive isolation and speciation. Although this conceptual framework is supported by correlative data, there is little direct empirical evidence. Here, we used a microdissection laser to alter the morphology of the external male genitalia in Drosophila, a widely used genetic model for both genital shape and cryptic female choice. We evaluate the effect of precision alterations to lobe morphology on both interspecific and intraspecific mating, and demonstrate experimentally that the male genital lobes do not affect copulation duration or cryptic female choice, contrary to long-standing assumptions regarding the role of the lobes in this model system. Rather, we demonstrate that the lobes are essential for copulation to occur. Moreover, slight alterations to the lobes significantly reduced copulatory success only in competitive environments, identifying precopulatory sexual selection as a potential contributing force behind genital diversification.

  3. Female reproductive function in areas affected by radiation after the Chernobyl power station accident

    SciTech Connect

    Kulakov, V.I.; Sokur, T.N.; Volobuev, A.I.

    1993-07-01

    This paper reports the results of a comprehensive survey of the effects of the accidental release of radiation caused by the accident at the Chernobyl nuclear power station in April 1986. The accident and the resulting release of radiation and radioactive products into the atmosphere produced the most serious environmental contamination so far recorded. We have concentrated on evaluating the outcomes and health risks to women, their reproductive situation, and consequences for their progeny. We have concentrated on two well-defined areas: the Chechersky district of the Gomel region in Belorussia and the Polessky district of the Kiev region in the Ukraine. A number of investigations were carried out on 688 pregnant women and their babies, and data were obtained from 7000 labor histories of the development of newborns for a period of 8 years (3 years before the accident and 5 years after it). Parameters examined included birth rate, thyroid pathology, extragenital pathology such as anemias, renal disorders, hypertension, and abnormalities in the metabolism of fats, complications of gestation, spontaneous abortions, premature deliveries, perinatal morbidity and mortality, stillbirths and early neonatal mortality, infections and inflammatory diseases, neurological symptoms and hemic disturbances in both mothers and infants, trophic anomalies, and biochemical and structural changes in the placenta. Several exogenous, complicating influences were also considered such as psycho-emotional factors, stress, lifestyle changes, and others caused directly by the hazardous situation and by its consequences such as treatment, removal from affected areas, etc. 9 figs.

  4. Gonad morphology, gametogenesis, and reproductive modes in fishes of the tribe Starksiini (Teleostei, Blenniiformes).

    PubMed

    Fishelson, Lev; Baldwin, Carole C; Hastings, Philip A

    2013-05-01

    A comparative study of the reproductive organs in 17 of the 30 species of the tribe Starksiini (Labrisomidae, Blenniiformes) and related labrisomids reveals the major traits of gamete form and production and likely reproductive modes. The testes are of the lobular type and have a testicular gland and sperm ducts. Isodiametric sperm (aquasperm) with a globular head or anisodiametric sperm (introsperm) with an elongate head, or both, were observed in the studied species. Both types have either one or two flagella in the sperm tail. Ovaries of the Starksiini are bilobed and exhibit synchronous or asynchronous egg production. Although viviparity or "ovoviviparity" reportedly characterizes the group, our study revealed evidence of both internal and external fertilization and three modes of reproduction. External fertilization or ovuliparity is suggested for the Starksia atlantica and S. lepicoelia species complexes by the presence in males of a short genital papilla that is not reinforced through adhesion with the first anal-fin spine and by the absence of sperm within the ovaries. Internal fertilization and zygoparity is indicated for most species by the presence of an intromittent papilla in males that is adhered to the first anal-fin spine, "nests" of sperm within the ovaries, absence of embryos within the ovarian lamellae and usually thick egg envelopes bearing dense covers of adhesive filaments. Internal fertilization and embryoparity is indicated for starksia fulva and Xenomedea rhodopyga by an intromittent papilla that is adhered to the first anal-fin spine of males, anisodiametric sperm in males, delicate egg envelopes without adhesive filaments and developing embryos within follicular envelopes or within the follicle in females. Although many of these features are seen in the internally fertilizing clinid blennies, starksiins differ in retaining the testicular gland typical of labrisomids and in lacking sperm packaging typical of other internally fertilizing

  5. Classification accuracy of algorithms for blood chemistry data for three aquaculture-affected marine fish species.

    PubMed

    Coz-Rakovac, R; Topic Popovic, N; Smuc, T; Strunjak-Perovic, I; Jadan, M

    2009-11-01

    The objective of this study was determination and discrimination of biochemical data among three aquaculture-affected marine fish species (sea bass, Dicentrarchus labrax; sea bream, Sparus aurata L., and mullet, Mugil spp.) based on machine-learning methods. The approach relying on machine-learning methods gives more usable classification solutions and provides better insight into the collected data. So far, these new methods have been applied to the problem of discrimination of blood chemistry data with respect to season and feed of a single species. This is the first time these classification algorithms have been used as a framework for rapid differentiation among three fish species. Among the machine-learning methods used, decision trees provided the clearest model, which correctly classified 210 samples or 85.71%, and incorrectly classified 35 samples or 14.29% and clearly identified three investigated species from their biochemical traits.

  6. Adult diet affects lifespan and reproduction of the fruit-feeding butterfly Charaxes fulvescens.

    PubMed

    Molleman, Freerk; Ding, Jimin; Wang, Jane-Ling; Zwaan, Bas J; Carey, James R; Brakefield, Paul M

    2008-10-01

    Fruit-feeding butterflies are among the longest lived Lepidoptera. While the use of pollen-derived amino acids by Heliconius butterflies has been interpreted as important for the evolution of extended lifespans, very little is known about the life-history consequences of frugivory. This issue is addressed by investigating effects of four adult diets (sugar, sugar with amino acids, banana, and moistened banana) on lifespan and reproduction in the fruit-feeding butterfly Charaxes fulvescens Aurivillius (Lepidoptera: Nymphalidae). Female butterflies were collected from Kibale National Park, Uganda, and kept individually in cages near their natural habitat and data were collected on lifespan, oviposition, and hatching of eggs. Lifespan in captivity was longer for the sugar and the amino acid cohort, than for the banana cohorts. The longitudinal pattern of oviposition was erratic, with many days without oviposition and few periods with high numbers of eggs laid. Butterflies typically did not lay eggs during their 1st week in captivity and the length of the period between capture and first reproduction was significantly shorter for butterflies fed moistened banana. The length of the reproduction period (first reproduction-last reproduction in captivity) and the reproduction rate (total number of eggs/length of the reproduction period) did not differ significantly between the diet treatments. Those fed with amino acid and moistened banana had significantly higher egg hatchability than those fed with sugar and banana. We found no evidence for a lifespan cost of reproduction. Our results show that (1) female C. fulvescens can use amino acids in their diet for laying fertile eggs, (2) more wing-wear does correlate with lower survival in captivity (indicating aging in the wild), but not with intensity of reproduction (providing no evidence for reproductive aging), and (3) fruit-feeding butterflies may be dietary restricted in the field.

  7. Determination of factors affecting relapse of vaginitis among reproductive-aged women: An experimental study

    PubMed Central

    Parsapour, Roxana; Majlessi, Fereshteh; Rahimiforoushani, Abbas; Sadeghi, Roya

    2017-01-01

    Introduction Vaginitis is a common problem for women, especially in reproductive-aged women. It is a worldwide health problem with many side effects but could be prevented by a health-promoting lifestyle related to vagina health. The aim of this study was to determine the factors affecting relapse of vaginitis. Methods In this experimental study, 350 reproductive-aged women with vaginitis were selected from 10 health centers in Kermanshah (Iran) during 2015 and were equally included in the intervention and control groups. To collect data, a researcher-created questionnaire, which included sociodemographic and health-promoting lifestyle questions, was used. The educational intervention was performed over 20 sessions, each lasting 25–35 minutes. An intervention group was educated by face-to-face education, pamphlets, phone contacts, text messages, and social media. Another group continued the routine clinic education and treatment without contacting the intervention group. Data were analyzed through chi-square and a logistics regression model using IBM-SPSS version 20. Results The results of the study indicated a significant relation between sociodemographic characteristics such as women and their husbands’ literacy, job, family size, income, area for each member of family, tendency of pregnancy, body mass index (BMI), and caesarean experience (p<0.001) and vaginitis. In addition, significant relationships between health-promoting lifestyle dimensions and prevention of vaginitis were identified. Relapse after intervention in the intervention group was 27.7% and 72.3% in the control group. According to the logistic regression analysis, chance for relapse of vaginitis in the group that did not receive intervention was more than the same chance in the intervention group (OR=5.14). Conclusion Health-promoting lifestyle intervention influences prevention of vaginitis. Health-promoting lifestyle, literacy promotion, prevention of caesarian, and obesity are beneficial

  8. Abdominally implanted satellite transmitters affect reproduction and survival rather than migration of large shorebirds

    USGS Publications Warehouse

    Hooijmeijer, Jos C. E. W.; Gill, Robert E.; Mulcahy, Daniel M.; Tibbitts, T. Lee; Kentie, Rosemarie; Gerritsen, Gerrit J.; Bruinzeel, Leo W.; Tijssen, David C.; Harwood, Christopher M.; Piersma, Theunis

    2014-01-01

    Satellite telemetry has become a common technique to investigate avian life-histories, but whether such tagging will affect fitness is a critical unknown. In this study, we evaluate multi-year effects of implanted transmitters on migratory timing and reproductive performance in shorebirds. Shorebirds increasingly are recognized as good models in ecology and evolution. That many of them are of conservation concern adds to the research responsibilities. In May 2009, we captured 56 female Black-tailed Godwits Limosa limosa limosa during late incubation in The Netherlands. Of these, 15 birds were equipped with 26-g satellite transmitters with a percutaneous antenna (7.8 % ± 0.2 SD of body mass), surgically implanted in the coelom. We compared immediate nest survival, timing of migration, subsequent nest site fidelity and reproductive behaviour including egg laying with those of the remaining birds, a comparison group of 41 females. We found no effects on immediate nest survival. Fledging success and subsequent southward and northward migration patterns of the implanted birds conformed to the expectations, and arrival time on the breeding grounds in 2010–2012 did not differ from the comparison group. Compared with the comparison group, in the year after implantation, implanted birds were equally faithful to the nest site and showed equal territorial behaviour, but a paucity of behaviours indicating nests or clutches. In the 3 years after implantation, the yearly apparent survival of implanted birds was 16 % points lower. Despite intense searching, we found only three eggs of two implanted birds; all were deformed. A similarly deformed egg was reported in a similarly implanted Whimbrel Numenius phaeopus returning to breed in central Alaska. The presence in the body cavity of an object slightly smaller than a normal egg may thus lead to egg malformation and, likely, reduced egg viability. That the use of implanted satellite transmitters in these large shorebirds

  9. Growth and social behavior in a cichlid fish are affected by social rearing environment and kinship

    NASA Astrophysics Data System (ADS)

    Hesse, Saskia; Thünken, Timo

    2014-04-01

    Living in groups is a widespread phenomenon in many animal taxa. The reduction of predation risk is thought to be an important cause for the formation of groups. Consequently, grouping behavior is particularly pronounced during vulnerable life stages, i.e., as juveniles. However, group living does not only provide benefits but also imposes costs on group members, e.g., increased competition for food. Thus, benefits of grouping behavior might not be evident when predation risk is absent. The adaptive significance of living and also developing in a group independent from predation risk has received relatively little attention although this might have important implications on the evolution and maintenance of group living. The first aim of the present study was to examine whether the social environment affects juvenile performance in the cichlid fish Pelvicachromis taeniatus and, secondly, whether kinship affects social behavior. Kin selection theory predicts benefits from grouping with kin. Here, we demonstrate that juveniles reared in a group grow on average faster compared to juveniles reared in isolation under standardized laboratory conditions without predation risk. Furthermore, we found significant differences in social behavior between juveniles reared in a group and reared in isolation. Fish reared in isolation were significantly more aggressive and less willing to shoal than group-reared fish. As expected, genetic relatedness influenced social behavior in group-reared fish as well: dyads of juveniles consisting of kin showed increased group cohesiveness compared to non-kin dyads. We discuss the potential benefits of group living in general and living with kin in particular.

  10. Growth and social behavior in a cichlid fish are affected by social rearing environment and kinship.

    PubMed

    Hesse, Saskia; Thünken, Timo

    2014-04-01

    Living in groups is a widespread phenomenon in many animal taxa. The reduction of predation risk is thought to be an important cause for the formation of groups. Consequently, grouping behavior is particularly pronounced during vulnerable life stages, i.e., as juveniles. However, group living does not only provide benefits but also imposes costs on group members, e.g., increased competition for food. Thus, benefits of grouping behavior might not be evident when predation risk is absent. The adaptive significance of living and also developing in a group independent from predation risk has received relatively little attention although this might have important implications on the evolution and maintenance of group living. The first aim of the present study was to examine whether the social environment affects juvenile performance in the cichlid fish Pelvicachromis taeniatus and, secondly, whether kinship affects social behavior. Kin selection theory predicts benefits from grouping with kin. Here, we demonstrate that juveniles reared in a group grow on average faster compared to juveniles reared in isolation under standardized laboratory conditions without predation risk. Furthermore, we found significant differences in social behavior between juveniles reared in a group and reared in isolation. Fish reared in isolation were significantly more aggressive and less willing to shoal than group-reared fish. As expected, genetic relatedness influenced social behavior in group-reared fish as well: dyads of juveniles consisting of kin showed increased group cohesiveness compared to non-kin dyads. We discuss the potential benefits of group living in general and living with kin in particular.

  11. Dietary vitamin A, ascorbic acid and α-tocopherol affect the gonad development and reproductive performance of starry flounder Platichthys stellatus broodstock

    NASA Astrophysics Data System (ADS)

    Wang, Jiying; Li, Baoshan; Liu, Xudong; Ma, Jingjing; Wang, Shixin; Zhang, Limin

    2014-03-01

    The present trial was conducted with starry flounder Platichthys stellatus broodstock to evaluate the effects of dietary vitamin A, ascorbic acid, and α-tocopherol on the gonadal development and reproductive performance. 8 000 IU/kg diet vitamin A (VA group), 500 mg/kg diet ascorbic acid (Vcpp group), or 250 mg/kg diet α-tocopherol (α-TA group) was added into basal diet to create 3 vitamin experimental diets, respectively. Each diet was fed to 450 starry flounder broodstock for 104 days. Samples were collected weekly. The gonadosomatic index (GSI) of 3 vitamin experimental groups first decreased and then increased. Maximum GSI of Vcpp group was higher than that of α-TA group but lower than that of VA group. The spawning periods of 3 vitamin experimental groups lasted 49, 56, and 45 days, respectively. No mature eggs were observed in the control group during the trial. The absolute fecundity (AF) and relative fecundity (RF) of α-TA group was higher than that of Vcpp group but lower than that of VA group. The results suggest that different vitamins play different roles in the fish reproductive process. Vitamin A stimulated the maturation of the ovary, ascorbic acid prolonged the spawning period, and α-tocopherol affected the development of the eggs.

  12. Reproductive Hazards

    MedlinePlus

    ... such as lead and mercury Chemicals such as pesticides Cigarettes Some viruses Alcohol For men, a reproductive hazard can affect the sperm. For a woman, a reproductive hazard can cause different effects during pregnancy, depending on when she is exposed. ...

  13. Biomonitoring of Environmental Status and Trends (BEST) Program: Environmental contaminants, health indicators, and reproductive biomarkers in fish from the Colorado River basin

    USGS Publications Warehouse

    Hinck, Jo Ellen; Blazer, Vicki; Denslow, Nancy D.; Gross, Timothy S.; Echols, Kathy R.; Davis, Anne P.; May, Tom W.; Orazio, Carl E.; Coyle, James J.; Tillitt, Donald E.

    2006-01-01

    Seven fish species were collected from 14 sites on rivers in the Colorado River Basin (CDRB) from August to October 2003. Spatial trends in the concentrations of accumulative contaminants were documented and contaminant effects on the fish were assessed. Sites were located on the mainstem of the Colorado River and on the Yampa, Green, Gunnison, San Juan, and Gila Rivers. Common carp (Cyprinus carpio), black bass (Micropterus sp.), and channel catfish (Ictalurus punctatus) were the targeted species. Fish were field-examined for external and internal anomalies, selected organs were weighed to compute somatic indices, and tissue and fluid samples were preserved for fish health and reproductive biomarker analyses. Composite samples of whole fish, grouped by species and gender, from each site were analyzed for organochlorine and elemental contaminants using performance-based and instrumental methods. 2,3,7,8-tetrachlorodibenzo-p-dioxin-like activity (TCDD-EQ) was measured using the H4IIE rat hepatoma cell bioassay. Selenium (Se) and mercury (Hg) concentrations were elevated throughout the CDRB, and pesticides concentrations were greatest in fish from agricultural areas in the Lower Colorado River and Gila River. Selenium concentrations exceeded toxicity thresholds for fish (>1.0 ?g/g ww) at all sites except from the Gila River at Hayden, Arizona. Mercury concentrations were elevated (>0.1 ?g/g ww) in fish from the Yampa River at Lay, Colorado; the Green River at Ouray National Wildlife Refuge (NWR), Utah and San Rafael, Utah; the San Juan River at Hogback Diversion, New Mexico; and the Colorado River at Gold Bar Canyon, Utah, Needles, California, and Imperial Dam, Arizona. Concentrations of p,p'-DDE were relatively high in fish from Arlington, Arizona (>1.0 ?g/g ww) and Phoenix, Arizona (>0.5 ?g/g ww). Concentrations of other banned pesticides including toxaphene, total chlordanes, and dieldrin were also greatest at these two sites but did not exceed toxicity thresholds

  14. Can aircraft noise less than or equal 115 to dBA adversely affect reproductive outcome in USAF women?

    NASA Astrophysics Data System (ADS)

    Brubaker, P. A.

    1985-06-01

    It has been suggested, mainly through animal studies, that exposure to high noise levels may be associated with lower birth weight, reduced gestational length and other adverse reproductive outcomes. Few studies have been done on humans to show this association. The Air Force employs pregnant women in areas where there is a high potential for exposure to high noise levels. This study proposes a method to determine if there is an association between high frequency noise levels or = 115 dBA and adverse reproductive outcomes through a review of records and self-administered questionnaires in a case-comparison design. Prevelance rates will be calculated and a multiple logistic regression analysis computed for the independent variables that can affect reproduction.

  15. Asexual Reproduction Does Not Apparently Increase the Rate of Chromosomal Evolution: Karyotype Stability in Diploid and Triploid Clonal Hybrid Fish (Cobitis, Cypriniformes, Teleostei)

    PubMed Central

    Majtánová, Zuzana; Choleva, Lukáš; Symonová, Radka; Ráb, Petr; Kotusz, Jan; Pekárik, Ladislav; Janko, Karel

    2016-01-01

    Interspecific hybridization, polyploidization and transitions from sexuality to asexuality considerably affect organismal genomes. Especially the last mentioned process has been assumed to play a significant role in the initiation of chromosomal rearrangements, causing increased rates of karyotype evolution. We used cytogenetic analysis and molecular dating of cladogenetic events to compare the rate of changes of chromosome morphology and karyotype in asexually and sexually reproducing counterparts in European spined loach fish (Cobitis). We studied metaphases of three sexually reproducing species and their diploid and polyploid hybrid clones of different age of origin. The material includes artificial F1 hybrid strains, representatives of lineage originated in Holocene epoch, and also individuals of an oldest known age to date (roughly 0.37 MYA). Thereafter we applied GISH technique as a marker to differentiate parental chromosomal sets in hybrids. Although the sexual species accumulated remarkable chromosomal rearrangements after their speciation, we observed no differences in chromosome numbers and/or morphology among karyotypes of asexual hybrids. These hybrids possess chromosome sets originating from respective parental species with no cytogenetically detectable recombinations, suggesting their integrity even in a long term. The switch to asexual reproduction thus did not provoke any significant acceleration of the rate of chromosomal evolution in Cobitis. Asexual animals described in other case studies reproduce ameiotically, while Cobitis hybrids described here produce eggs likely through modified meiosis. Therefore, our findings indicate that the effect of asexuality on the rate of chromosomal change may be context-dependent rather than universal and related to particular type of asexual reproduction. PMID:26808475

  16. Asexual Reproduction Does Not Apparently Increase the Rate of Chromosomal Evolution: Karyotype Stability in Diploid and Triploid Clonal Hybrid Fish (Cobitis, Cypriniformes, Teleostei).

    PubMed

    Majtánová, Zuzana; Choleva, Lukáš; Symonová, Radka; Ráb, Petr; Kotusz, Jan; Pekárik, Ladislav; Janko, Karel

    2016-01-01

    Interspecific hybridization, polyploidization and transitions from sexuality to asexuality considerably affect organismal genomes. Especially the last mentioned process has been assumed to play a significant role in the initiation of chromosomal rearrangements, causing increased rates of karyotype evolution. We used cytogenetic analysis and molecular dating of cladogenetic events to compare the rate of changes of chromosome morphology and karyotype in asexually and sexually reproducing counterparts in European spined loach fish (Cobitis). We studied metaphases of three sexually reproducing species and their diploid and polyploid hybrid clones of different age of origin. The material includes artificial F1 hybrid strains, representatives of lineage originated in Holocene epoch, and also individuals of an oldest known age to date (roughly 0.37 MYA). Thereafter we applied GISH technique as a marker to differentiate parental chromosomal sets in hybrids. Although the sexual species accumulated remarkable chromosomal rearrangements after their speciation, we observed no differences in chromosome numbers and/or morphology among karyotypes of asexual hybrids. These hybrids possess chromosome sets originating from respective parental species with no cytogenetically detectable recombinations, suggesting their integrity even in a long term. The switch to asexual reproduction thus did not provoke any significant acceleration of the rate of chromosomal evolution in Cobitis. Asexual animals described in other case studies reproduce ameiotically, while Cobitis hybrids described here produce eggs likely through modified meiosis. Therefore, our findings indicate that the effect of asexuality on the rate of chromosomal change may be context-dependent rather than universal and related to particular type of asexual reproduction.

  17. Adult diet affects lifespan and reproduction of the fruit-feeding butterfly Charaxes fulvescens

    PubMed Central

    Molleman, Freerk; Ding, Jimin; Wang, Jane-Ling; Zwaan, Bas J.; Carey, James R.; Brakefield, Paul M.

    2009-01-01

    Fruit-feeding butterflies are among the longest lived Lepidoptera. While the use of pollen-derived amino acids by Heliconius butterflies has been interpreted as important for the evolution of extended lifespans, very little is known about the life-history consequences of frugivory. This issue is addressed by investigating effects of four adult diets (sugar, sugar with amino acids, banana, and moistened banana) on lifespan and reproduction in the fruit-feeding butterfly Charaxes fulvescens Aurivillius (Lepidoptera: Nymphalidae). Female butterflies were collected from Kibale National Park, Uganda, and kept individually in cages near their natural habitat and data were collected on lifespan, oviposition, and hatching of eggs. Lifespan in captivity was longer for the sugar and the amino acid cohort, than for the banana cohorts. The longitudinal pattern of oviposition was erratic, with many days without oviposition and few periods with high numbers of eggs laid. Butterflies typically did not lay eggs during their 1st week in captivity and the length of the period between capture and first reproduction was significantly shorter for butterflies fed moistened banana. The length of the reproduction period (first reproduction–last reproduction in captivity) and the reproduction rate (total number of eggs/length of the reproduction period) did not differ significantly between the diet treatments. Those fed with amino acid and moistened banana had significantly higher egg hatchability than those fed with sugar and banana. We found no evidence for a lifespan cost of reproduction. Our results show that (1) female C. fulvescens can use amino acids in their diet for laying fertile eggs, (2) more wing-wear does correlate with lower survival in captivity (indicating aging in the wild), but not with intensity of reproduction (providing no evidence for reproductive aging), and (3) fruit-feeding butterflies may be dietary restricted in the field. PMID:19774093

  18. Conditions during adulthood affect cohort-specific reproductive success in an Arctic-nesting goose population

    PubMed Central

    Bearhop, Stuart; Hilton, Geoff M.; Walsh, Alyn; Fox, Anthony David

    2016-01-01

    Variation in fitness between individuals in populations may be attributed to differing environmental conditions experienced among birth (or hatch) years (i.e., between cohorts). In this study, we tested whether cohort fitness could also be explained by environmental conditions experienced in years post-hatch, using 736 lifelong resighting histories of Greenland white-fronted geese (Anser albifrons flavirostris) marked in their first winter. Specifically, we tested whether variation in age at first successful reproduction, the size of the first successful brood and the proportion of successful breeders by cohort was explained by environmental conditions experienced on breeding areas in west Greenland during hatch year, those in adulthood prior to successful reproduction and those in the year of successful reproduction, using North Atlantic Oscillation indices as proxies for environmental conditions during these periods. Fifty-nine (8%) of all marked birds reproduced successfully (i.e., were observed on wintering areas with young) only once in their lifetime and 15 (2%) reproduced successfully twice or thrice. Variation in age at first successful reproduction was explained by the environmental conditions experienced during adulthood in the years prior to successful reproduction. Birds bred earliest (mean age 4) when environmental conditions were ‘good’ prior to the year of successful reproduction. Conversely, birds successfully reproduced at older ages (mean age 7) if they experienced adverse conditions prior to the year of successful reproduction. Hatch year conditions and an interaction between those experienced prior to and during the year of successful reproduction explained less (marginally significant) variation in age at first successful reproduction. Environmental conditions did not explain variation in the size of the first successful brood or the proportion of successful breeders. These findings show that conditions during adulthood prior to the year of

  19. Wolbachia Affects Reproduction and Population Dynamics of the Coffee Berry Borer (Hypothenemus hampei): Implications for Biological Control

    PubMed Central

    Mariño, Yobana A.; Verle Rodrigues, José C.; Bayman, Paul

    2017-01-01

    Wolbachia are widely distributed endosymbiotic bacteria that influence the reproduction and fitness of their hosts. In recent years the manipulation of Wolbachia infection has been considered as a potential tool for biological control. The coffee berry borer (CBB), Hypothenemus hampei, is the most devastating coffee pest worldwide. Wolbachia infection in the CBB has been reported, but until now the role of Wolbachia in CBB reproduction and fitness has not been tested. To address this issue we reared the CBB in artificial diets with and without tetracycline (0.1% w/v) for ten generations. Tetracycline reduced significantly the relative proportion of Wolbachia in the CBB microbiota from 0.49% to 0.04%. This reduction affected CBB reproduction: females fed with tetracycline had significantly fewer progeny, lower fecundity, and fewer eggs per female. Tetracycline also reduced the population growth rate (λ), net reproductive rate (R0), and mean generation time (T) in CBB; the reduction in population growth was mostly due to variation in fertility, according to life time response experiments (LTREs) analysis. Our results suggest that Wolbachia contribute to the reproductive success of the CBB and their manipulation represents a possible approach to CBB biocontrol mediated by microbiome management. PMID:28085049

  20. Wolbachia Affects Reproduction and Population Dynamics of the Coffee Berry Borer (Hypothenemus hampei): Implications for Biological Control.

    PubMed

    Mariño, Yobana A; Verle Rodrigues, José C; Bayman, Paul

    2017-01-11

    Wolbachia are widely distributed endosymbiotic bacteria that influence the reproduction and fitness of their hosts. In recent years the manipulation of Wolbachia infection has been considered as a potential tool for biological control. The coffee berry borer (CBB), Hypothenemus hampei, is the most devastating coffee pest worldwide. Wolbachia infection in the CBB has been reported, but until now the role of Wolbachia in CBB reproduction and fitness has not been tested. To address this issue we reared the CBB in artificial diets with and without tetracycline (0.1% w/v) for ten generations. Tetracycline reduced significantly the relative proportion of Wolbachia in the CBB microbiota from 0.49% to 0.04%. This reduction affected CBB reproduction: females fed with tetracycline had significantly fewer progeny, lower fecundity, and fewer eggs per female. Tetracycline also reduced the population growth rate (λ), net reproductive rate (R₀), and mean generation time (T) in CBB; the reduction in population growth was mostly due to variation in fertility, according to life time response experiments (LTREs) analysis. Our results suggest that Wolbachia contribute to the reproductive success of the CBB and their manipulation represents a possible approach to CBB biocontrol mediated by microbiome management.

  1. Temporal dynamics of a local fish community are strongly affected by immigration from the surrounding metacommunity.

    PubMed

    Stoffels, Rick J; Clarke, Kenneth Robert; Linklater, Danielle S

    2015-01-01

    A 5-year time series of annual censuses was collected from a large floodplain lake to determine how dynamics of the local fish community were affected by changes in hydrological connectivity with the surrounding metacommunity. The lake was disconnected from the metacommunity for 1 year prior to our study and remained disconnected until 3 months before our third annual census, when a flood reconnected the lake to the metacommunity. We determined how changes in connectivity affected temporal dynamics of (1) local community composition and (2) the population composition, condition, and growth of catfish, to shed light on how immigration of other species might affect local population dynamics. Before reconnection, the community was likely shaped by interactions between the local environment and species traits. The reconnection caused significant immigration and change in community composition and correlated with a significant and abrupt decline in catfish condition, growth, and abundance; effects likely due to the immigration of a competitor with a similar trophic niche: carp. The community was slow to return to its preconnection state, which may be due to dispersal traits of the fishes, and a time-lag in the recovery of the local catfish population following transient intensification of species interactions. The dynamics observed were concordant with the species sorting and mass-effects perspectives of metacommunity theory. Floods cause episodic dispersal in floodplain fish metacommunities, and so, flood frequency determines the relative importance of regional and local processes. Local processes may be particularly important to certain species, but these species may need sufficient time between floods for population increase, before the next flood-induced dispersal episode brings competitors and predators that might cause population decline. Accordingly, species coexistence in these metacommunities may be facilitated by spatiotemporal storage effects, which may in

  2. Temporal dynamics of a local fish community are strongly affected by immigration from the surrounding metacommunity

    PubMed Central

    Stoffels, Rick J; Clarke, Kenneth Robert; Linklater, Danielle S

    2015-01-01

    A 5-year time series of annual censuses was collected from a large floodplain lake to determine how dynamics of the local fish community were affected by changes in hydrological connectivity with the surrounding metacommunity. The lake was disconnected from the metacommunity for 1 year prior to our study and remained disconnected until 3 months before our third annual census, when a flood reconnected the lake to the metacommunity. We determined how changes in connectivity affected temporal dynamics of (1) local community composition and (2) the population composition, condition, and growth of catfish, to shed light on how immigration of other species might affect local population dynamics. Before reconnection, the community was likely shaped by interactions between the local environment and species traits. The reconnection caused significant immigration and change in community composition and correlated with a significant and abrupt decline in catfish condition, growth, and abundance; effects likely due to the immigration of a competitor with a similar trophic niche: carp. The community was slow to return to its preconnection state, which may be due to dispersal traits of the fishes, and a time-lag in the recovery of the local catfish population following transient intensification of species interactions. The dynamics observed were concordant with the species sorting and mass-effects perspectives of metacommunity theory. Floods cause episodic dispersal in floodplain fish metacommunities, and so, flood frequency determines the relative importance of regional and local processes. Local processes may be particularly important to certain species, but these species may need sufficient time between floods for population increase, before the next flood-induced dispersal episode brings competitors and predators that might cause population decline. Accordingly, species coexistence in these metacommunities may be facilitated by spatiotemporal storage effects, which may in

  3. Novel use of an ultrasonic cleaning device for fish reproductive studies

    NASA Astrophysics Data System (ADS)

    Barnes, L. M.; van der Meulen, D. E.; Orchard, B. A.; Gray, C. A.

    2013-02-01

    A major challenge commonly faced in reproductive studies of teleosts is to cost effectively and safely separate oocytes from one another and from surrounding ovarian tissue. This challenge is exacerbated when ovarian tissue has been chemically preserved. Using Platycephalus caeruleopunctatus, a platycephalid species found within oceanic waters along the east coast of Australia, as an example species, within this study we describe and assess the utility of an ultrasonic cleaning device to separate oocytes from preserved ovarian tissue. The ultrasonic cleaning device was observed to separate oocytes from the surrounding ovarian tissue within less than 80 min of treatment and had no deleterious effects on the number of oocytes present. Treatment within the ultrasonic cleaning device reduced oocyte diameters at a constant rate of 3.9 μm per hour among the samples tested. As the ultrasonic cleaning device was able to separate oocytes from connective tissue within 80 min, this observed rate of reduction in oocyte diameters is unlikely to be detected at the resolution at which oocytes are traditionally measured and is less than that reported to occur using alternate chemically derived methods to separate oocytes from preserved connective tissue. Following the assessment of using an ultrasonic cleaning device to separate oocytes from ovarian tissue for P. caeruleopunctatus, this technique has been successfully employed to separate oocytes from preserved ovarian tissue for a variety of other teleost species including Macquaria colonorum, Platycephalus longispinis and Ratabulus diversidens. The use of an ultrasonic cleaning device to separate oocytes from preserved ovarian tissue will increase the efficiency of future investigations into teleost reproductive biology and potentially in other fields of research where particle separation and analysis are required.

  4. High summer temperatures affect the survival and reproduction of olive fruit fly (Diptera: Tephritidae).

    PubMed

    Wang, Xin-Geng; Johnson, Marshall W; Daane, Kent M; Nadel, Hannah

    2009-10-01

    The olive fruit fly, Bactrocera oleae (Rossi) (Diptera: Tephritidae), is an invasive pest in California. Identifying environmental constraints that affect the geographic distribution and abundance of any invasive insect pest is fundamental to its effective management. California's Central Valley, where most commercial olives are grown, is extremely hot during the summer, with maximum daily temperatures consistently >35.0 degrees C. This study examined the effects of two diurnal temperature regimens (low 18.3 degrees C, high 35.0 or 37.8 degrees C) reflecting summer conditions in the valley, and one control temperature regimen (low 18.3 degrees C, high 23.9 degrees C) on the fly's survival and reproductive success in the laboratory. The temperature regimen of 18.3-35.0 degrees C resulted in delayed egg maturation and reduced production of mature eggs compared with the control temperature regimen. Egg maturation was possible at the higher temperature regimen when females were provided with water and food, and egg-laying occurred during the cold phase of the temperature cycle. Access to olive fruit and oviposition itself further promoted egg maturation. Under exposure to the 18.3-35.0 degrees C temperature regimen, approximately 50% of eggs died, and the remainder that hatched died as first instars. No egg hatch occurred at the temperature treatment of 18.3-37.8 degrees C. We confirmed these laboratory results through field cage studies with adult B. oleae, conducted in the summer of 2007 and 2008. Under ambient summer temperatures, adult B. oleae survived for 1-2 wk, and females readily laid eggs when provided water and food. No offspring developed in midsummer of 2007, and <2% of the offspring developed to adults in summer 2008 trials. These results suggest that high summer temperatures limit the fly's abundance in California's Central Valley.

  5. ANDROGENS AND ENVIRONMENTAL ANTIANDROGENS AFFECT REPRODUCTIVE DEVELOPMENT AND PLAY BEHAVIOR IN THE SPRAGUE-DAWLEY RAT

    EPA Science Inventory

    Abstract: In mammals, exposure to androgens early in development is essential for masculinization of the male reproductive phenotype. Male fetuses exposed to antiandrogens during perinatal life are permanently demasculinized in their morphology and physiology, whereas exposure to...

  6. Ice cover affects the growth of a stream-dwelling fish.

    PubMed

    Watz, Johan; Bergman, Eva; Piccolo, John J; Greenberg, Larry

    2016-05-01

    Protection provided by shelter is important for survival and affects the time and energy budgets of animals. It has been suggested that in fresh waters at high latitudes and altitudes, surface ice during winter functions as overhead cover for fish, reducing the predation risk from terrestrial piscivores. We simulated ice cover by suspending plastic sheeting over five 30-m-long stream sections in a boreal forest stream and examined its effects on the growth and habitat use of brown trout (Salmo trutta) during winter. Trout that spent the winter under the artificial ice cover grew more than those in the control (uncovered) sections. Moreover, tracking of trout tagged with passive integrated transponders showed that in the absence of the artificial ice cover, habitat use during the day was restricted to the stream edges, often under undercut banks, whereas under the simulated ice cover condition, trout used the entire width of the stream. These results indicate that the presence of surface ice cover may improve the energetic status and broaden habitat use of stream fish during winter. It is therefore likely that reductions in the duration and extent of ice cover due to climate change will alter time and energy budgets, with potentially negative effects on fish production.

  7. Perceived Risk of Predation Affects Reproductive Life-History Traits in Gambusia holbrooki, but Not in Heterandria formosa

    PubMed Central

    Mukherjee, Shomen; Heithaus, Michael R.; Trexler, Joel C.; Ray-Mukherjee, Jayanti; Vaudo, Jeremy

    2014-01-01

    Key to predicting impacts of predation is understanding the mechanisms through which predators impact prey populations. While consumptive effects are well-known, non-consumptive predator effects (risk effects) are increasingly being recognized as important. Studies of risk effects, however, have focused largely on how trade-offs between food and safety affect fitness. Less documented, and appreciated, is the potential for predator presence to directly suppress prey reproduction and affect life-history characteristics. For the first time, we tested the effects of visual predator cues on reproduction of two prey species with different reproductive modes, lecithotrophy (i.e. embryonic development primarily fueled by yolk) and matrotrophy (i.e. energy for embryonic development directly supplied by the mother to the embryo through a vascular connection). Predation risk suppressed reproduction in the lecithotrophic prey (Gambusia holbrokii) but not the matrotroph (Heterandria formosa). Predator stress caused G. holbrooki to reduce clutch size by 43%, and to produce larger and heavier offspring compared to control females. H. formosa, however, did not show any such difference. In G. holbrooki we also found a significantly high percentage (14%) of stillbirths in predator-exposed treatments compared to controls (2%). To the best of our knowledge, this is the first direct empirical evidence of predation stress affecting stillbirths in prey. Our results suggest that matrotrophy, superfetation (clutch overlap), or both decrease the sensitivity of mothers to environmental fluctuation in resource (food) and stress (predation risk) levels compared to lecithotrophy. These mechanisms should be considered both when modeling consequences of perceived risk of predation on prey-predator population dynamics and when seeking to understand the evolution of reproductive modes. PMID:24551171

  8. Perceived risk of predation affects reproductive life-history traits in Gambusia holbrooki, but not in Heterandria formosa.

    PubMed

    Mukherjee, Shomen; Heithaus, Michael R; Trexler, Joel C; Ray-Mukherjee, Jayanti; Vaudo, Jeremy

    2014-01-01

    Key to predicting impacts of predation is understanding the mechanisms through which predators impact prey populations. While consumptive effects are well-known, non-consumptive predator effects (risk effects) are increasingly being recognized as important. Studies of risk effects, however, have focused largely on how trade-offs between food and safety affect fitness. Less documented, and appreciated, is the potential for predator presence to directly suppress prey reproduction and affect life-history characteristics. For the first time, we tested the effects of visual predator cues on reproduction of two prey species with different reproductive modes, lecithotrophy (i.e. embryonic development primarily fueled by yolk) and matrotrophy (i.e. energy for embryonic development directly supplied by the mother to the embryo through a vascular connection). Predation risk suppressed reproduction in the lecithotrophic prey (Gambusia holbrokii) but not the matrotroph (Heterandria formosa). Predator stress caused G. holbrooki to reduce clutch size by 43%, and to produce larger and heavier offspring compared to control females. H. formosa, however, did not show any such difference. In G. holbrooki we also found a significantly high percentage (14%) of stillbirths in predator-exposed treatments compared to controls (2%). To the best of our knowledge, this is the first direct empirical evidence of predation stress affecting stillbirths in prey. Our results suggest that matrotrophy, superfetation (clutch overlap), or both decrease the sensitivity of mothers to environmental fluctuation in resource (food) and stress (predation risk) levels compared to lecithotrophy. These mechanisms should be considered both when modeling consequences of perceived risk of predation on prey-predator population dynamics and when seeking to understand the evolution of reproductive modes.

  9. Reproductive strategies and seasonal changes in the somatic indices of seven small-bodied fishes in Atlantic Canada in relation to study design for environmental effects monitoring.

    PubMed

    Barrett, Timothy J; Brasfield, Sandra M; Carroll, Leslie C; Doyle, Meghan A; van den Heuvel, Michael R; Munkittrick, Kelly R

    2015-05-01

    Small-bodied fishes are more commonly being used in environmental effects monitoring (EEM) studies. There is a lack of understanding of the biological characteristics of many small-bodied species, which hinders study designs for monitoring studies. For example, 72% of fish population surveys in Canada's EEM program for pulp and paper mills that used small-bodied fishes were conducted outside of the reproductive period of the species. This resulted in an inadequate assessment of the EEM program's primary effect endpoint (reproduction) for these studies. The present study examined seasonal changes in liver size, gonad size, and condition in seven freshwater and estuarine small-bodied fishes in Atlantic Canada. These data were used to examine differences in reproductive strategies and patterns of energy storage among species. Female gonadal recrudescence in all seven species began primarily in the 2-month period in the spring before spawning. Male gonadal development was concurrent with females in five species; however, gonadal recrudescence began in the fall in male three-spined stickleback (Gasterosteus aculeatus) and slimy sculpin (Cottus cognatus). The spawning period for each species was estimated from the decline in relative ovary size after its seasonal maximum value in spring. The duration of the spawning period reflected the reproductive strategy (single vs multiple spawning) of the species. Optimal sampling periods to assess reproductive impacts in each species were determined based on seasonal changes in ovary size and were identified to be during the prespawning period when gonads are developing and variability in relative gonad size is at a minimum.

  10. "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

    behaviour. A new programme of work therefore aims to establish the distribution of key benthivorous species across the River Trent catchment, UK, measure their impact on bed disturbance, and investigate the spatial and temporal controls of disturbance intensity. In sum, work to date confirms that benthivorous fish affect fluvial processes - this is no fairy tale - but ongoing work is needed to evaluate their large-scale, aggregate significance and their contribution to life's role in driving and moderating sediment movements across Earth's surface.

  11. Reproductive rate, not dominance status, affects fecal glucocorticoid levels in breeding female meerkats.

    PubMed

    Barrette, Marie-France; Monfort, Steven L; Festa-Bianchet, Marco; Clutton-Brock, Tim H; Russell, Andrew F

    2012-04-01

    Glucocorticoid hormones (GCs) have been studied intensively to understand the associations between physiological stress and reproductive skew in animal societies. However, we have little appreciation of the range of either natural levels within and among individuals, or the associations among dominance status, reproductive rate and GCs levels during breeding. To address these shortcomings, we examined variation in fecal glucocorticoid metabolites (fGC) during breeding periods in free-ranging female meerkats (Suricata suricatta) over 11 years. The vast majority of variation in fGC levels was found within breeding events by the same female (~87%), with the remaining variation arising among breeding events and among females. Concentrations of fGC generally tripled as pregnancy progressed. However, females with a high reproductive rate, defined as those conceiving within a month following parturition (mean = 9 days postpartum), showed significant reductions in fGC in the final 2 weeks before parturition. Despite these reductions, females with a high reproductive rate had higher fGC levels at conception of the following litter than those breeding at a low rate. After controlling for the higher reproductive rate of dominants, we found no association between levels of fGC and either age or dominance status. Our results suggest that one should be cautious about interpreting associations between dominance status, reproductive skew and GCs levels, without knowledge of the natural variation in GCs levels within and among females.

  12. Unsteady flow affects swimming energetics in a labriform fish (Cymatogaster aggregata).

    PubMed

    Roche, D G; Taylor, M K; Binning, S A; Johansen, J L; Domenici, P; Steffensen, J F

    2014-02-01

    Unsteady water flows are common in nature, yet the swimming performance of fishes is typically evaluated at constant, steady speeds in the laboratory. We examined how cyclic changes in water flow velocity affect the swimming performance and energetics of a labriform swimmer, the shiner surfperch, Cymatogaster aggregata, during station holding. Using intermittent-flow respirometry, we measured critical swimming speed (Ucrit), oxygen consumption rates (O2) and pectoral fin use in steady flow versus unsteady flows with either low- [0.5 body lengths (BL) s(-1)] or high-amplitude (1.0 BL s(-1)) velocity fluctuations, with a 5 s period. Individuals in low-amplitude unsteady flow performed as well as fish in steady flow. However, swimming costs in high-amplitude unsteady flow were on average 25.3% higher than in steady flow and 14.2% higher than estimated values obtained from simulations based on the non-linear relationship between swimming speed and oxygen consumption rate in steady flow. Time-averaged pectoral fin use (fin-beat frequency measured over 300 s) was similar among treatments. However, measures of instantaneous fin use (fin-beat period) and body movement in high-amplitude unsteady flow indicate that individuals with greater variation in the duration of their fin beats were better at holding station and consumed less oxygen than fish with low variation in fin-beat period. These results suggest that the costs of swimming in unsteady flows are context dependent in labriform swimmers, and may be influenced by individual differences in the ability of fishes to adjust their fin beats to the flow environment.

  13. 17α-Ethinyl estradiol affects anxiety and shoaling behavior in adult male zebra fish (Danio rerio).

    PubMed

    Reyhanian, Nasim; Volkova, Kristina; Hallgren, Stefan; Bollner, Tomas; Olsson, Per-Erik; Olsén, Håkan; Hällström, Inger Porsch

    2011-09-01

    Ethinyl estradiol is a potent endocrine disrupting compound in fish and ubiquitously present in the aquatic environment. In this study, we exposed adult zebra fish (Danio rerio) males to 0, 5 or 25 ng Ethinyl estradiol/L for 14 days and analyzed the effects on non-reproductive behavior. Effects of treatment of the exposed males was shown by vitellogenin induction, while brain aromatase (CYP 19B) activity was not significantly altered. Both concentrations of Ethinyl estradiol significantly altered the behavior in the Novel tank test, where anxiety is determined as the tendency to stay at the bottom when introduced into an unfamiliar environment. The effects were, however, opposite for the two concentrations. Fish that were exposed to 5 ng/L had longer latency before upswim, fewer transitions to the upper half and shorter total time spent in the upper half compared with control fish, while 25 ng Ethinyl estradiol treatment resulted in shorter latency and more and longer visits to the upper half. The swimming activity of 25, but not 5 ng-exposed fish were slightly but significantly reduced, and these fish tended to spend a lot of time at the surface. We also studied the shoaling behavior as the tendency to leave a shoal of littermates trapped behind a Plexiglas barrier at one end of the test tank. The fish treated with Ethinyl estradiol had significantly longer latency before leaving shoal mates and left the shoal fewer times. Further, the fish exposed to 5 ng/L also spent significantly less time away from shoal than control fish. Fertilization frequency was higher in males exposed to 5 ng/L Ethinyl estradiol when compared with control males, while no spawning was observed after treatment with 25 ng/L. The testes from both treatment groups contained a normal distribution of spermatogenesis stages, and no abnormality in testis morphology could be observed. In conclusion, we have observed effects on two behaviors not related to reproduction in zebra fish males after

  14. Histopathologic Effects of Estrogens on Marine Fishes

    EPA Science Inventory

    Endocrine-disrupting chemicals (EDCs), such as estrogens estradiol (E2) and ethinylestradiol (EE2) have been reported to affect fish reproduction. This study histologically compared and evaluated effects of EDCs in two species of treated fish. Juvenile male summer flounder (Paral...

  15. Field evidence of reproduction impairment through sperm DNA damage in the fish nase (Chondrostoma nasus) in anthropized hydrosystems.

    PubMed

    Devaux, Alain; Bony, Sylvie; Plenet, Sandrine; Sagnes, Pierre; Segura, Samuel; Suaire, Rémi; Novak, Morgane; Gilles, André; Olivier, Jean-Michel

    2015-12-01

    This work aims to explore in the field the relationship between the integrity of sperm DNA and the quality of offspring as a possible cause of the decline of a feral fish population through reproduction impairment. Mature nase (Chondrostoma nasus) were caught during the breeding season in three locations (A-C) of the Rhône River basin and gametes collected by stripping. Sampling locations were chosen according to the following gradient of contamination due to human activities on the watershed: A≤Bfish caught in the most contaminated area reached high values up to 15% and 80%, respectively, the hypothesis that the observed nase decline in Rhône River stemming through selection forces can be put forward.

  16. Small pelagic fish reproductive strategies in upwelling systems: A natal homing evolutionary model to study environmental constraints

    NASA Astrophysics Data System (ADS)

    Brochier, T.; Colas, F.; Lett, C.; Echevin, V.; Cubillos, L. A.; Tam, J.; Chlaida, M.; Mullon, C.; Fréon, P.

    2009-12-01

    Although little is known about the individual-level mechanisms that influence small pelagic fish species’ reproductive strategy, Mullon et al. [Mullon, C., Cury, P., Penven, P., 2002. Evolutionary individual-based model for the recruitment of anchovy ( Engraulis capensis) in the southern Benguela. Canadian Journal of Fisheries and Aquatic Sciences 59, 910-922] showed that the observed anchovy spawning patterns in the southern Benguela Current system off South Africa could be accurately reproduced by simulating a natal homing reproductive strategy, i.e. individuals spawning at their natal date and place. Here we used a similar method, i.e., an individual-based model of the natal homing reproductive strategy, and applied it to other upwelling systems: the northern Humboldt Current system off Peru, the southern Humboldt Current system off Chile and the central Canary Current system off Morocco. We investigated the spatial (horizontal and vertical) and seasonal spawning patterns that emerged after applying different environmental constraints in the model, and compared these to observed spawning patterns of sardine and anchovy in their respective systems. The selective environmental constraints tested were: (1) lethal temperature; (2) retention over the continental shelf; and (3) avoidance of dispersive structures. Simulated horizontal spatial patterns and seasonal patterns compared reasonably well with field data, but vertical patterns in most cases did not. Similarly to what was found for the southern Benguela, temperature was a determinant constraint in the southern Humboldt. The shelf retention constraint led to selection of a particular spawning season during the period of minimum upwelling in all three of the upwelling regions considered, and to spatial patterns that matched observed anchovy spawning off Chile and sardine spawning off Morocco. The third constraint, avoidance of dispersive structures, led to the emergence of a spawning season during the period of

  17. Pulsed resources affect the timing of first breeding and lifetime reproductive success of tawny owls.

    PubMed

    Millon, A; Petty, S J; Lambin, X

    2010-03-01

    1. According to life-history theory, environmental variability and costs of reproduction account for the prevalence of delayed reproduction in many taxa. Empirical estimates of the fitness consequences of different ages at first breeding in a variable environment are few however such that the contributions of environmental and individual variability remains poorly known. 2. Our objectives were to elucidate processes that underpin variation in delayed reproduction and to assess lifetime consequences of the age of first breeding in a site-faithful predator, the tawny owl Strix aluco L. subjected to fluctuating selection linked to cyclical variation in vole density (typically 3-year cycles with low, increasing and decreasing vole densities in successive years). 3. A multistate capture-recapture model revealed that owl cohorts had strikingly different juvenile survival prospects, with estimates ranging from 0.08 to 0.33 respectively for birds born in Decrease and Increase phases of the vole cycle. This resulted in a highly skewed population structure with >75% of local recruits being reared during Increase years. In contrast, adult survival remained constant throughout a vole cycle. The probability of commencing reproduction was lower at age 1 than at older ages, and especially so for females. From age 2 onwards, pre-breeders had high probabilities of entering the breeding population. 4. Variation in lifetime reproductive success was driven by the phase of the vole cycle in which female owls started their breeding career (26-47% of variance explained, whether based on the number of local recruits or fledglings), more than by age at first breeding or by conditions experienced at birth. Females who postponed reproduction to breed for the first time at age 3 during an Increase phase, produced more recruits, even when accounting for birds that may have died before reproduction. No such effects were detected for males. 5. Sex-specific costs of early reproduction may have

  18. The Behavioral Physiology of Labroid Fishes.

    DTIC Science & Technology

    1992-09-01

    Sea Grant College Program Office, Dept. of Commerce, under Grant No. NA86-AA-D-SC090, Sea Grant Project Nos. R/A-26-PD and R/B-106-PD. Reproduction in...be used for growth and reproduction (Torres and Somero, 1988). Other factors such as fish handling and feeding also affect respiration rates. Handling...ectotherms often encounter temperatures that are low enough to prohibit functions such as movement, reproduction , feeding, and digestion and may remain

  19. Screening of ecotoxicological, qualitative and reproductive variables in male European sea bass Dicentrarchus labrax (L.) reared in three different fish farms: Facility location and typology.

    PubMed

    Cangialosi, Maria Vittoria; Corsi, Ilaria; Bonacci, Stefano; Sensini, Cristiana; Cicero, Nicola; Focardi, Silvano; Mazzola, Antonio

    2013-04-01

    The aim of this study was to investigate the influence of both facility location and typology of fish farm on some ecotoxicological, qualitative and reproductive variables in European sea bass Dicentrarchus labrax L. Several variables were investigated: gonado-somatic index (GSI), liver-somatic index (LSI); 7-ethoxyresorufin-O-deethylase (EROD), benzo(a)pyrene monooxygenase and acetylcholinesterase activities; glutathione (GSH), testosterone, 17β-estradiol, total lipid, phospholipid (PL) and triglyceride contents. In addition, the histological sections of gonads were examined. Results suggest that LSI, EROD activity, GSI, GSH, PL, hormone levels and gonad morphology were influenced by different facility locations and typologies of fish farm.

  20. Pre-spawning parental stress affects channel catfish, Ictalurus punctatus reproduction and subsequent progeny performance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Routine fish handling procedures associated with seining, selecting, transportation, crowding, weighing, and stripping have shown to cause negative physiological responses to hatchery performance. In teleosts, cortisol is the main corticosteroid released during stress, and hence, plasma cortisol co...

  1. Identification of Sex and Female’s Reproductive Stage in Commercial Fish Species through the Quantification of Ribosomal Transcripts in Gonads

    PubMed Central

    Rojo-Bartolomé, Iratxe; Diaz de Cerio, Oihane; Diez, Guzman; Cancio, Ibon

    2016-01-01

    The estimation of maturity and sex of fish stocks in European waters is a requirement of the EU Data Collection Framework as part of the policy to improve fisheries management. On the other hand, research on fish biology is increasingly focused in molecular approaches, researchers needing correct identification of fish sex and reproductive stage without necessarily having in house the histological know-how necessary for the task. Taking advantage of the differential gene transcription occurring during fish sex differentiation and gametogenesis, the utility of 5S ribosomal RNA (5S rRNA) and General transcription factor IIIA (gtf3a) in the molecular identification of sex and gametogenic stage was tested in different economically-relevant fish species from the Bay of Biscay. Gonads of 9 fish species (, Atlantic, Atlantic-chub and horse mackerel, blue whiting, bogue, European anchovy, hake and pilchard and megrim), collected from local commercial fishing vessels were histologically sexed and 5S and 18S rRNA concentrations were quantified by capillary electrophoresis to calculate a 5S/18S rRNA index. Degenerate primers permitted cloning and sequencing of gtf3a fragments in 7 of the studied species. 5S rRNA and gtf3a transcript levels, together with 5S/18S rRNA index, distinguished clearly ovaries from testis in all of the studied species. The values were always higher in females than in males. 5S/18S rRNA index values in females were always highest when fish were captured in early phases of ovary development whilst, in later vitellogenic stages, the values decreased significantly. In megrim and European anchovy, where gonads in different oogenesis stages were obtained, the 5S/18S rRNA index identified clearly gametogenic stage. This approach, to the sexing and the quantitative non-subjective identification of the maturity stage of female fish, could have multiple applications in the study of fish stock dynamics, fish reproduction and fecundity and fish biology in

  2. Forebrain AVT and courtship in a fish with male alternative reproductive tactics.

    PubMed

    Grober, Matthew S; George, Andrew A; Watkins, Kelly K; Carneiro, Luis A; Oliveira, Rui F

    In this paper, we present the results of cellular and molecular studies on the neuroendocrine correlates of male sexual polymorphism in a population of the blenniid fish Salaria pavo (Risso). Bigger and older males defend nests, whereas smaller and younger males mimic female nuptial coloration and behavior to gain access to nests and sneak fertilizations. In this population, sex-role reversal in courtship also occurs (i.e., females are the courting sex). Immunocytochemistry and in situ hybridization were used to examine the production of arginine vasotocin (AVT) peptide and messenger RNA, respectively. The expression of AVT mRNA on a per-cell basis was correlated with mating behavior, rather than with sex morphotype, which suggests that the greater level of AVT mRNA expression in females and sneakers is correlated with the production of courtship behavior. On the other hand, the number and size of AVT peptide-producing cells in both male types is higher or larger, respectively, than in females, which suggests that it is correlated with sex morphotype, rather than with mating behavior.

  3. 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

  4. 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.

  5. Tropical photoperiods affect reproductive development in the musk shrew, Suncus murinus.

    PubMed

    Wayne, N L; Rissman, E F

    1991-09-01

    The purpose of the present studies was to determine whether reproductive development in male musk shrews (original stock from Guam Island, 13 degrees N latitude) could be altered by small, ecologically relevant changes in photoperiod. In the first experiment, effects of changes in photoperiod equivalent to those seen between the 2 solstices on Guam Island (90 min) on reproductive maturation were investigated. The results showed that a 90-min difference in photoperiod had a significant effect on weights of various androgen-sensitive target tissues. Furthermore, there was little evidence that the preweaning photoperiod had an effect on the response to the postweaning photoperiod. In the second experiment, effects of changes in photoperiod equivalent to those seen between the equinoxes and solstices on Guam Island (45 min) on reproductive maturation were investigated. The results showed that both a decrease and an increase in photoperiod by 45 min had a significant effect on weights of various androgen-sensitive target tissues. Overall, these results suggest that animals living close to the equator can potentially use small changes in day length to alter or time reproductive function.

  6. Sexual experience affects reproductive behavior and preoptic androgen receptors in male mice

    PubMed Central

    Swaney, William T.; Dubose, Brittany N.; Curley, James P.; Champagne, Frances A.

    2012-01-01

    Reproductive behavior in male rodents is made up of anticipatory and consummatory elements which are regulated in the brain by sensory systems, reward circuits and hormone signaling. Gonadal steroids play a key role in the regulation of male sexual behavior via steroid receptors in the hypothalamus and preoptic area. Typical patterns of male reproductive behavior have been characterized, however these are not fixed but are modulated by adult experience. We assessed the effects of repeated sexual experience on male reproductive behavior of C57BL/6 mice; including measures of olfactory investigation of females, mounting, intromission and ejaculation. The effects of sexual experience on the number of cells expressing either androgen receptor (AR) or estrogen receptor alpha (ERα) in the primary brain nuclei regulating male sexual behavior was also measured. Sexually experienced male mice engaged in less sniffing of females before initiating sexual behavior and exhibited shorter latencies to mount and intromit, increased frequency of intromission, and increased duration of intromission relative to mounting. No changes in numbers of ERα-positive cells were observed, however sexually experienced males had increased numbers of AR-positive cells in the medial preoptic area (MPOA); the primary regulatory nucleus for male sexual behavior. These results indicate that sexual experience results in a qualitative change in male reproductive behavior in mice that is associated with increased testosterone sensitivity in the MPOA and that this nucleus may play a key integrative role in mediating the effects of sexual experience on male behavior. PMID:22266118

  7. Validation of a refined short-term adult fish reproductive test with improved power for mummichog (Fundulus heteroclitus) to test complex effluents.

    PubMed

    Bosker, Thijs; Hewitt, L Mark; Munkittrick, Kelly R; MacLatchy, Deborah L

    2010-10-01

    Short-term adult fish reproductive tests are widely used to assess the toxicity of chemicals and waste streams. However, these tests often have low power to detect differences in egg production among treatments, due to high variance and small sample sizes, limiting their effectiveness for informing regulatory decisions. A protocol for a fish reproductive test using mummichog (Fundulus heteroclitus) was refined to increase statistical power. Three studies using the original protocol were compared with three studies using the refined protocol. Tank pre-selection and sample size increased the a priori power from 11.2% to 85.7%. After exposure, average power levels were 62.0%, a more than five-fold increase compared to studies that used the original protocol (power of 15.0%). There was a high level of consistency compared to the original protocol; differences >33% in female and male gonad size and egg production could be detected among treatments. This study demonstrates that a refinement process can address shortcomings in short-term adult fish reproductive protocols, creating a solid foundation for further standardization and possible regulatory use.

  8. Human affection exchange: VI. Further tests of reproductive probability as a predictor of men's affection with their adult sons.

    PubMed

    Floyd, Kory; Sargent, Jack E; Di Corcia, Mark

    2004-04-01

    The authors examined the communication of affection in men's relationships with their fathers. Drawing from Affection Exchange Theory, the authors advanced four predictions: (a) heterosexual men receive more affection from their own fathers than do homosexual or bisexual men, (b) fathers communicate affection to their sons more through supportive activities than through direct verbal statements or nonverbal gestures, (c) affectionate communication between fathers and sons is linearly related to closeness and interpersonal involvement between them, and (d) fathers' awareness of their sons' sexual orientation is associated with the amount of affection that the fathers communicate to them. Participants were 170 adult men who completed questionnaires regarding affectionate communication in their relationships with their fathers. Half of the men were self-identified as exclusively heterosexual, and the other half were self-identified as exclusively homosexual or bisexual. The results supported all predictions substantially.

  9. Social Variables Affecting Mate Preferences, Copulation and Reproductive Outcome in a Pack of Free-Ranging Dogs

    PubMed Central

    Valsecchi, Paola; Natoli, Eugenia

    2014-01-01

    Mating and reproductive outcome is often determined by the simultaneous operation of different mechanisms like intra-sexual competition, mating preferences and sexual coercion. The present study investigated how social variables affected mating outcome in a pack of free-ranging dogs, a species supposed to have lost most features of the social system of wolves during domestication. We found that, although the pack comprised multiple breeding individuals, both male copulation success and female reproductive success were positively influenced by a linear combination of dominance rank, age and leadership. Our results also suggest that mate preferences affect mating outcome by reinforcing the success of most dominant individuals. In particular, during their oestrous period bitches clearly searched for the proximity of high-ranking males who displayed affiliative behaviour towards them, while they were more likely to reject the males who intimidated them. At the same time, male courting effort and male-male competition for receptive females appeared to be stronger in the presence of higher-ranking females, suggesting a male preference for dominant females. To our knowledge, these results provide the first clear evidence of social regulation of reproductive activities in domestic dogs, and suggest that some common organizing mechanisms may contribute to shape the social organization of both dogs and wolves. PMID:24905360

  10. Biofilm Formation by the Fish Pathogen Flavobacterium columnare: Development and Parameters Affecting Surface Attachment

    PubMed Central

    Cai, Wenlong; De La Fuente, Leonardo

    2013-01-01

    Flavobacterium columnare is a bacterial fish pathogen that affects many freshwater species worldwide. The natural reservoir of this pathogen is unknown, but its resilience in closed aquaculture systems posits biofilm as the source of contagion for farmed fish. The objectives of this study were (i) to characterize the dynamics of biofilm formation and morphology under static and flow conditions and (ii) to evaluate the effects of temperature, pH, salinity, hardness, and carbohydrates on biofilm formation. Nineteen F. columnare strains, including representatives of all of the defined genetic groups (genomovars), were compared in this study. The structure of biofilm was characterized by light microscopy, confocal laser scanning microscopy, and scanning electron microscopy. F. columnare was able to attach to and colonize inert surfaces by producing biofilm. Surface colonization started within 6 h postinoculation, and microcolonies were observed within 24 h. Extracellular polysaccharide substances and water channels were observed in mature biofilms (24 to 48 h). A similar time course was observed when F. columnare formed biofilm in microfluidic chambers under flow conditions. The virulence potential of biofilm was confirmed by cutaneous inoculation of channel catfish fingerlings with mature biofilm. Several physicochemical parameters modulate attachment to surfaces, with the largest influence being exerted by hardness, salinity, and the presence of mannose. Maintenance of hardness and salinity values within certain ranges could prevent biofilm formation by F. columnare in aquaculture systems. PMID:23851087

  11. Spatial scale affects community concordance among fishes, benthic macroinvertebrates, and bryophytes in streams.

    PubMed

    Paavola, Riku; Muotka, Timo; Virtanen, Risto; Heino, Jani; Jackson, Donald; Maki-Petäys, Aki

    2006-02-01

    Owing to the lack of information about the distribution patterns of many taxonomic groups, biodiversity conservation strategies commonly rely on a surrogate taxa approach for identifying areas of maximum conservation potential. Macroinvertebrates or fish are the most likely candidates for such a role in many freshwater systems. The usefulness of the surrogate taxa depends largely on community concordance, i.e., the degree of similarity in community patterns among taxonomic groups across a set of sites. We examined the effect of the spatial scale of a. study on the strength of community concordance among macroinvertebrates, bryophytes, and fish by comparing the concordance between ordinations of these groups in 101 boreal stream sites. We specifically asked if communities spanning several drainages are more concordant than those originating from a single drainage system. Our results indicate that community concordance is affected by spatial extent, being variable and generally weak at the scale of individual drainages, but strong across multiple drainage systems and ecoregions. We attribute this finding to different taxonomic groups responding to similar environmental factors and sharing a similar latitudinal gradient of community structure when viewed across large spatial scales. We also identified a "gradient of concordance," with sites contributing disproportionately to community concordance being in relatively large streams with high microhabitat variability. Overall, our results suggest that the degree of community concordance among freshwater organism groups depends critically on the spatial extent of the study, and surrogate groups at the scale of single river systems should be used with caution.

  12. Biofilm formation by the fish pathogen Flavobacterium columnare: development and parameters affecting surface attachment.

    PubMed

    Cai, Wenlong; De La Fuente, Leonardo; Arias, Covadonga R

    2013-09-01

    Flavobacterium columnare is a bacterial fish pathogen that affects many freshwater species worldwide. The natural reservoir of this pathogen is unknown, but its resilience in closed aquaculture systems posits biofilm as the source of contagion for farmed fish. The objectives of this study were (i) to characterize the dynamics of biofilm formation and morphology under static and flow conditions and (ii) to evaluate the effects of temperature, pH, salinity, hardness, and carbohydrates on biofilm formation. Nineteen F. columnare strains, including representatives of all of the defined genetic groups (genomovars), were compared in this study. The structure of biofilm was characterized by light microscopy, confocal laser scanning microscopy, and scanning electron microscopy. F. columnare was able to attach to and colonize inert surfaces by producing biofilm. Surface colonization started within 6 h postinoculation, and microcolonies were observed within 24 h. Extracellular polysaccharide substances and water channels were observed in mature biofilms (24 to 48 h). A similar time course was observed when F. columnare formed biofilm in microfluidic chambers under flow conditions. The virulence potential of biofilm was confirmed by cutaneous inoculation of channel catfish fingerlings with mature biofilm. Several physicochemical parameters modulate attachment to surfaces, with the largest influence being exerted by hardness, salinity, and the presence of mannose. Maintenance of hardness and salinity values within certain ranges could prevent biofilm formation by F. columnare in aquaculture systems.

  13. Prenatal light exposure affects development of behavioural lateralization in a livebearing fish.

    PubMed

    Dadda, Marco; Bisazza, Angelo

    2012-09-01

    The existence of individual differences in handedness and other lateralized functions is an unresolved problem. Genetic factors account for only a small proportion of the variance but the contribution of environmental influences is still largely unexplored. In chicks and zebrafish the amount of environmental light reaching embryos during development greatly influences the lateralization of adults. To investigate whether a similar effect is present in livebearers, we measured behavioural lateralization in ten-day-old goldbelly topminnows born from females that have been maintained at high or low light intensities during pregnancy. Fish from high-light treatment were significantly lateralized in both visual and motor tests while fish exposed to low light intensities were not. As observed in chicks and zebrafish, the main consequence of light exposure was the alignment of the laterality of different individuals in the same direction. Lateralization is known to affect a number of fitness-related traits in topminnow and we suggest that light influence may be part of an adaptive mechanism allowing to adjust the developmental trajectories of offspring to the prevailing environmental conditions.

  14. Duration of Exposure to Elevated Temperature Affects Competitive Interactions in Juvenile Reef Fishes

    PubMed Central

    Warren, Donald T.; Donelson, Jennifer M.; McCormick, Mark I.; Ferrari, Maud C. O.; Munday, Philip L.

    2016-01-01

    Climate change will affect key ecological processes that structure natural communities, but the outcome of interactions between individuals and species will depend on their thermal plasticity. We tested how short- and long-term exposure to projected future temperatures affects intraspecific and interspecific competitive interactions in two species of coral reef damselfishes. In conspecific contests, juvenile Ambon damselfish, Pomacentrus amboinensis, exhibited no change in aggressive interactions after 4d exposure to higher temperatures. However, after 90d of exposure, fish showed a nonadaptive reduction in aggression at elevated temperatures. Conversely, 4d exposure to higher temperature increased aggression towards conspecifics in the lemon damselfish, Pomacentrus moluccensis. 90d exposure began to reduce this pattern, but overall there was little effect of temperature. Aggression in interspecific contests increased with short-term exposure, but was significantly lower after long-term exposure indicative of acclimation. Our results show how the length of exposure to elevated temperature can affect the outcome of competitive interactions. Furthermore, we illustrate that results from intraspecific contests may not accurately predict interspecific interactions, which will challenge our ability to generalise the effects of warming on competitive interactions. PMID:27736924

  15. Herbivory and competition interact to affect reproductive traits and mating system expression in Impatiens capensis.

    PubMed

    Steets, Janette A; Salla, Rhiannon; Ashman, Tia-Lynn

    2006-04-01

    As a step toward understanding how community context shapes mating system evolution, we investigated the combined role of two plant antagonisms, vegetative herbivory and intraspecific competition, for reproduction and mating system expression (relative production of selfing, cleistogamous and facultatively outcrossing, chasmogamous flowers and fruits) of Impatiens capensis. In a survey of I. capensis populations, we found that vegetative herbivory and intraspecific competition were positively correlated. In a greenhouse experiment where leaf damage and plant density were manipulated, multispecies interactions had dramatic effects on reproductive and mating system traits. Despite having additive effects on growth, herbivory and competition had nonadditive effects for mating system expression, chasmogamous fruit production, flower number and size, and cleistogamous flower production. Our results demonstrate that competitive interactions influence the effect of herbivory (and vice versa) on fitness components and mating system, and thus antagonisms may have unforeseen consequences for mating system evolution, population genetic diversity, and persistence.

  16. Honeybees enhance reproduction without affecting the outcrossing rate in endemic Pedicularis densispica (Orobanchaceae).

    PubMed

    Xia, J; Sun, S G; Guo, Y H

    2007-11-01

    There has been substantial debate in recent years surrounding the impact of introduced honeybees on native biota. This study reports on an investigation of Pedicularis densispica, a subalpine annual herb endemic to Southwest China, in an attempt to determine the impact of introduced domestic honeybees on pollen dispersal and thus on their reproductive success and mating system. Honeybees were introduced into the study site in 2004, and a sudden seasonal pollinator shift from bumblebees to honeybees was observed. Intra- and inter-plant visits by different pollinators were recorded in the field in 2003 and 2004. Fruit and seed sets prior to and after the pollinator shift were measured. Experimental pollinations were performed to characterize the breeding system. Outcrossing rates at the seed stage were estimated for both years using RAPD markers. Our results indicated that honeybees foraged between plants more frequently than bumblebees did. Our results also revealed that the introduction of honeybees significantly enhanced reproductive success. However, no significant difference was detected between the outcrossing rates due to bumblebee and honeybee pollination. P. densispica was almost completely outcrossing ( T(m) = 0.956 and 0.967, respectively in 2003 and 2004) but partially self-compatible. This study presents the first report of the outcrossing rate in the genus pedicularis and reveals a limited influence of pollination on the mating system in P. densispica. The pollinator shift did not reduce reproductive success of the plants and honeybees may be used to augment pollinator services for nectariferous P. densispica.

  17. Factors Affecting Fish Production and Fishing Quality in New Reservoirs, with Guidance on Timber Clearing, Basin Preparation, and Filling.

    DTIC Science & Technology

    1981-08-01

    humus and fallen leaves; (b) leachate and particulate matter from submerged terrestrial vegetation (herbaceous and woody); (c) inflow from the...fauna colonization of a new reservoir with particular reference to the Chironomidae. J. Fish. Res. Board Can., 27:213-232. Paxton, K. 0. and F. Stevenson

  18. The arginine-vasotocin and serotonergic systems affect interspecific social behaviour of client fish in marine cleaning mutualism.

    PubMed

    Triki, Zegni; Bshary, Redouan; Grutter, Alexandra S; Ros, Albert F H

    2017-03-14

    Many species engage in mutualistic relationships with other species. The physiological mechanisms that affect the course of such social interactions are little understood. In the cleaning mutualism, cleaner fish Labroides dimidiatus do not always act cooperatively by eating ectoparasites, but sometimes cheat by taking bites of mucus from so-called "client" reef fish. The physiological mechanisms in these interspecific interactions, however, are little studied. Here, we focussed on three neuromodulator systems known to play important roles in intraspecific social behaviour of vertebrates to examine their role in clients' interspecific behaviour. We subjected the client fish Scolopsis bilineatus to ectoparasites and the exogenous manipulation of the vasotocin (AVT), isotocin (IT) and serotonin systems to test how this affects client willingness to seek cleaning and client aggression towards cleaners. We found that a single dose of AVT agonist and a selective antagonist caused clients to seek proximity to cleaners, independently of ectoparasite infection. In contrast, in a direct encounter task, the selective blocker of serotonin 5HT2A/2C receptors, Ketanserin (KET), made client reef fish more aggressive towards cleaners in the absence of cleaners' bites of mucus. IT did not yield any significant effects. Our results suggest that the AVT system plays a role in social affiliation towards an interspecific partner, while the serotonin system affects clients' acceptance of level of proximity to cleaner fish during interactions. These two systems, therefore, were apparently co-opted from intraspecific social interactions to affect the course of interspecific ones also.

  19. Divergence for residual feed intake of Holstein-Friesian cattle during growth did not affect production and reproduction during lactation.

    PubMed

    Macdonald, K A; Thomson, B P; Waghorn, G C

    2016-11-01

    Residual feed intake (RFI) is the difference between actual and predicted dry matter intake (DMI) of individual animals. Recent studies with Holstein-Friesian calves have identified an ~20% difference in RFI during growth (calf RFI) and these groups remained divergent in RFI during lactation. The objective of the experiment described here was to determine if cows selected for divergent RFI as calves differed in milk production, reproduction or in the profiles of BW and body condition score (BCS) change during lactation, when grazing pasture. The cows used in the experiment (n=126) had an RFI of -0.88 and +0.75 kg DM intake/day for growth as calves (efficient and inefficient calf RFI groups, respectively) and were intensively grazed at four stocking rates (SR) of 2.2, 2.6, 3.1 and 3.6 cows/ha on self-contained farmlets, over 3 years. Each SR treatment had equal number of cows identified as low and high calf RFI, with 24, 28, 34 and 40/11 ha farmlet. The cows divergent for calf RFI were randomly allocated to each SR. Although SR affected production, calf RFI group (low or high) did not affect milk production, reproduction, BW, BCS or changes in these parameters throughout lactation. The most efficient animals (low calf RFI) lost similar BW and BCS as the least efficient (high calf RFI) immediately post-calving, and regained similar BW and BCS before their next calving. These results indicate that selection for RFI as calves to increase efficiency of feed utilisation did not negatively affect farm productivity variables (milk production, BCS, BW and reproduction) as adults when managed under an intensive pastoral grazing system.

  20. Subtle reproductive impairment through nitric oxide-mediated mechanisms in sea urchins from an area affected by harmful algal blooms

    PubMed Central

    Migliaccio, Oriana; Castellano, Immacolata; Di Cioccio, Davide; Tedeschi, Gabriella; Negri, Armando; Cirino, Paola; Romano, Giovanna; Zingone, Adriana; Palumbo, Anna

    2016-01-01

    The health of the sea urchin Paracentrotus lividus, a key species in the Mediterranean Sea, is menaced by several pressures in coastal environments. Here, we aimed at assessing the reproductive ability of apparently healthy P. lividus population in a marine protected area affected by toxic blooms of Ostreospsis cf. ovata. Wide-ranging analyses were performed in animals collected prior to and during the bloom, as well as at several times thereafter, during the reproductive season. Adults showed a low fertilization rate, along with high nitric oxide (NO) levels in the gonads and the nitration of the major yolk protein toposome, which is an important player in sea urchin development. Serious developmental anomalies were observed in the progeny, which persist several months after the bloom. NO levels were high in the different developmental stages, which also showed variations in the transcription of several genes that were found to be directly or indirectly modulated by NO. These results highlight subtle but important reproductive flaws transmitted from the female gonads to the offspring with the NO involvement. Despite a recovery along time after the bloom, insidious damages can be envisaged in the local sea urchin population, with possible reverberation on the whole benthic system. PMID:27192939

  1. A single hot event that does not affect survival but decreases reproduction in the diamondback moth, Plutella xylostella.

    PubMed

    Zhang, Wei; Zhao, Fei; Hoffmann, Ary A; Ma, Chun-Sen

    2013-01-01

    Extremely hot events (usually involving a few hours at extreme high temperatures in summer) are expected to increase in frequency in temperate regions under global warming. The impact of these events is generally overlooked in insect population prediction, since they are unlikely to cause widespread mortality, however reproduction may be affected by them. In this study, we examined such stress effects in the diamondback moth, Plutella xylostella. We simulated a single extreme hot day (maximum of 40°C lasting for 3, 4 or 5 h) increasingly experienced under field conditions. This event had no detrimental effects on immediate mortality, copulation duration, mating success, longevity or lifetime fecundity, but stressed females produced 21% (after 3 or 4 h) fewer hatched eggs because of a decline in the number and hatching success of eggs laid on the first two days. These negative effects on reproduction were no longer evident in the following days. Male heat exposure led to a similar but smaller effect on fertile egg production, and exposure extended pre-mating period in both sexes. Our results indicate that a single hot day can have detrimental effects on reproduction, particularly through maternal effects on egg hatching, and thereby influence the population dynamics of diamondback moth.

  2. Subtle reproductive impairment through nitric oxide-mediated mechanisms in sea urchins from an area affected by harmful algal blooms

    NASA Astrophysics Data System (ADS)

    Migliaccio, Oriana; Castellano, Immacolata; di Cioccio, Davide; Tedeschi, Gabriella; Negri, Armando; Cirino, Paola; Romano, Giovanna; Zingone, Adriana; Palumbo, Anna

    2016-05-01

    The health of the sea urchin Paracentrotus lividus, a key species in the Mediterranean Sea, is menaced by several pressures in coastal environments. Here, we aimed at assessing the reproductive ability of apparently healthy P. lividus population in a marine protected area affected by toxic blooms of Ostreospsis cf. ovata. Wide-ranging analyses were performed in animals collected prior to and during the bloom, as well as at several times thereafter, during the reproductive season. Adults showed a low fertilization rate, along with high nitric oxide (NO) levels in the gonads and the nitration of the major yolk protein toposome, which is an important player in sea urchin development. Serious developmental anomalies were observed in the progeny, which persist several months after the bloom. NO levels were high in the different developmental stages, which also showed variations in the transcription of several genes that were found to be directly or indirectly modulated by NO. These results highlight subtle but important reproductive flaws transmitted from the female gonads to the offspring with the NO involvement. Despite a recovery along time after the bloom, insidious damages can be envisaged in the local sea urchin population, with possible reverberation on the whole benthic system.

  3. A Single Hot Event That Does Not Affect Survival but Decreases Reproduction in the Diamondback Moth, Plutella xylostella

    PubMed Central

    Zhang, Wei; Zhao, Fei; Hoffmann, Ary A.; Ma, Chun-Sen

    2013-01-01

    Extremely hot events (usually involving a few hours at extreme high temperatures in summer) are expected to increase in frequency in temperate regions under global warming. The impact of these events is generally overlooked in insect population prediction, since they are unlikely to cause widespread mortality, however reproduction may be affected by them. In this study, we examined such stress effects in the diamondback moth, Plutella xylostella. We simulated a single extreme hot day (maximum of 40°C lasting for 3, 4 or 5 h) increasingly experienced under field conditions. This event had no detrimental effects on immediate mortality, copulation duration, mating success, longevity or lifetime fecundity, but stressed females produced 21% (after 3 or 4 h) fewer hatched eggs because of a decline in the number and hatching success of eggs laid on the first two days. These negative effects on reproduction were no longer evident in the following days. Male heat exposure led to a similar but smaller effect on fertile egg production, and exposure extended pre-mating period in both sexes. Our results indicate that a single hot day can have detrimental effects on reproduction, particularly through maternal effects on egg hatching, and thereby influence the population dynamics of diamondback moth. PMID:24116081

  4. Honey Bee (Apis mellifera) Queen Reproductive Potential Affects Queen Mandibular Gland Pheromone Composition and Worker Retinue Response

    PubMed Central

    Böröczky, Katalin; Schal, Coby; Tarpy, David R.

    2016-01-01

    Reproductive division of labor is one of the defining traits of honey bees (Apis mellifera), with non-reproductive tasks being performed by workers while a single queen normally monopolizes reproduction. The decentralized organization of a honey bee colony is maintained in large part by a bouquet of queen-produced pheromones, the distribution of which is facilitated by contact among workers throughout the hive. Previous studies have shown that the developmental fate of honey bee queens is highly plastic, with queens raised from younger worker larvae exhibiting higher measures of reproductive potential compared to queens raised from older worker larvae. We investigated differences in the chemical composition of the mandibular glands and attractiveness to workers of “high-quality” queens (i.e., raised from first instar worker larvae; more queen-like) and “low-quality” queens (i.e., raised from third instar worker larvae; more worker-like). We characterized the chemical profiles of the mandibular glands of high-quality queens and low-quality queens using GC-MS and used the worker retinue response as a measure of the attractiveness to workers of high-quality queens vs. low-quality queens. We found that queen quality affected the chemical profiles of mandibular gland contents differently across years, showing significant differences in the production of the queen mandibular pheromone (“QMP”) components HVA and 9-HDA in 2010, but no significant differences of any glandular compound in 2012. We also found that workers were significantly more attracted to high-quality queens than to low-quality queens in 2012, possibly because of increased attractiveness of their mandibular gland chemical profiles. Our results indicate that the age at which honey bee larvae enter the “queen-specific” developmental pathway influences the chemical composition of queen mandibular glands and worker behavior. However, these changes are not consistent across years, suggesting

  5. Rapid assessment of the toxicity of oil sands process-affected waters using fish cell lines.

    PubMed

    Sansom, Bryan; Vo, Nguyen T K; Kavanagh, Richard; Hanner, Robert; Mackinnon, Michael; Dixon, D George; Lee, Lucy E J

    2013-01-01

    Rapid and reliable toxicity assessment of oil sands process-affected waters (OSPW) is needed to support oil sands reclamation projects. Conventional toxicity tests using whole animals are relatively slow, costly, and often subjective, while at the same time requiring the sacrifice of test organisms as is the case with lethal dosage/concentration assays. A nonlethal alternative, using fish cell lines, has been developed for its potential use in supporting oil sands reclamation planning and to help predict the viability of aquatic reclamation models such as end-pit lakes. This study employed six fish cell lines (WF-2, GFSk-S1, RTL-W1, RTgill-W1, FHML, FHMT) in 24 h viability assays for rapid fluorometric assessment of cellular integrity and functionality. Forty-nine test water samples collected from the surface of oil sands developments in the Athabasca Oil Sands deposit, north of Fort McMurray, Alberta, Canada, were evaluated in blind. Small subsample volumes (8 ml) were mixed with 2 ml of 5× concentrated exposure media and used for direct cell exposures. All cell line responses in terms of viability as measured by Alamar blue assay, correlated well with the naphthenic acids (NA) content in the samples (R (2) between 0.4519 and 0.6171; p<0.0001) when data comparisons were performed after the bioassays. NA or total acid-extractable organics group has been shown to be responsible for most of the acute toxicity of OSPW and our results further corroborate this. The multifish cell line bioassay provides a strong degree of reproducibility among tested cell lines and good relative sensitivity of the cell line bioassay as compared to available in vivo data that could lead to cost effective, high-throughput screening assays.

  6. Factors affecting the quality of fish caught by Native Americans in the Zone 6 fishery 1991 through 1993

    SciTech Connect

    Abernethy, C.S.

    1994-09-01

    A program to monitor the salmon and steelhead (Oncorhynchus spp.) fishery in the lower Columbia River (Zone 6 fishery) was initiated in 1991 to respond to questions and comments frequently made by Native Americans at public meetings. Native Americans were concerned that the quality of the Columbia River had deteriorated and that the poor environmental conditions had affected the health and quality of fish they relied on for subsistence, ceremonial, religious, and commercial purposes. They also feared that eating contaminated fish might endanger the health of their children and future generations. Operations at the Hanford Site were listed as one of many causes of the deteriorating environment. Fisheries pathologists concluded that most of the external symptoms on fish were related to bacterial infection of gill net abrasions and pre-spawning trauma, and were not caused by pollution or contamination of the Columbia River. The pathologists also stated that consumption of the fish posed no threat to human consumers.

  7. Short-term fish reproduction assays with methyl tertiary butyl ether with zebrafish and fathead minnow: Implications for evaluation of potential for endocrine activity.

    PubMed

    Mihaich, Ellen; Erler, Steffen; Le Blanc, Gerald; Gallagher, Sean

    2015-09-01

    The authors report on short-term fish reproduction assays in zebrafish and fathead minnow conducted to examine the potential for methyl tertiary butyl ether (MTBE) to cause effects on the endocrine system. Both studies were performed under good laboratory practice and in accordance with Organisation for Economic Co-operation and Development and US Environmental Protection Agency test guidelines. The results of the first study demonstrated that exposure to a high test concentration (147 mg/L) of MTBE impaired reproductive output of female zebrafish, evident by a reduction in fecundity. Based on the endpoints evaluated in the present study however, there was no supporting evidence to indicate that this effect was caused by disruption of or interaction with the endocrine system. In the second study, fathead minnows exposed to a wider but lower range of test concentrations showed no effects on any reproductive parameter of male or female fish, at the maximum recommended testing concentration of 100 mg/L (62 mg/L measured). The results of these 2 guideline studies indicate that MTBE does not interact with the hypothalamic-pituitary-gonadal axis of zebrafish or fathead minnow.

  8. Methuselah-like genes affect development, stress resistance, lifespan and reproduction in Tribolium castaneum.

    PubMed

    Li, Chengjun; Zhang, Yi; Yun, Xiaopei; Wang, Yanyun; Sang, Ming; Liu, Xing; Hu, Xingxing; Li, Bin

    2014-10-01

    Methuselah (Mth) is associated with lifespan, stress resistance and reproduction in Drosophila melanogaster, but Mth is not present in nondrosophiline insects. A number of methuselah-likes (mthls) have been identified in nondrosophiline insects, but it is unknown whether the functions of mth are shared by mthls or are divergent from them. Five mthls have been identified in Tribolium castaneum. Although they have different developmental expression patterns, they all enhance resistance to starvation. Only mthl1 and mthl2 enhance resistance to high temperature, whereas mthl4 and mthl5 negatively regulate oxidative stress in T. castaneum. Unlike in the fly with mth mutation, knockdown of mthls, except mthl3, shortens the lifespan of T. castaneum. Moreover, mthl1 and mthl2 are critical for Tribolium development. mthl1 plays important roles in larval and pupal development and adult eclosion, while mthl2 is required for eclosion. Moreover, mthl1 and mthl2 silencing reduces the fertility of T. castaneum, and mthl1 and mthl4 are also essential for embryo development. In conclusion, mthls have a significant effect on insect development, lifespan, stress resistance and reproduction. These results provide experimental evidence for functional divergence among mthls/mth and clues for the signal transduction of Mthls.

  9. Genetic selection for temperament affects behaviour and the secretion of adrenal and reproductive hormones in sheep subjected to stress.

    PubMed

    Hawken, P A R; Luckins, N; Tilbrook, A; Fiol, C; Martin, G B; Blache, D

    2013-01-01

    We investigated the effect of genetic selection for temperament on the way that stressors affect the behaviour and the adrenal and reproductive axes of sheep. We tested three hypotheses: (i) isolation would increase cortisol secretion and decrease luteinising hormone (LH) secretion more in nervous sheep than in calm sheep; (ii) isolation combined with simulated human presence would increase cortisol secretion and decrease LH secretion more in nervous sheep than in calm sheep and (iii) isolation combined with stressors that were not specific to the selection process (i.e. non-selection stressors) would increase cortisol secretion and decrease LH secretion equally in calm and nervous sheep. Isolation alone increased cortisol secretion and decreased LH secretion in nervous sheep but not in calm sheep. Compared to calm sheep, nervous sheep were more agitated during the first 2 h of isolation but not during the second 2 h of isolation. Exposure to non-selection stressors increased cortisol secretion, decreased LH pulse amplitude and the mean plasma concentrations of LH in both calm and nervous sheep. We conclude that genetic selection for temperament affects the behavioural expression of the stress response and the secretion of adrenal and reproductive hormones during isolation, but has less impact on their reactivity to non-selection stressors.

  10. A review of sexually transmitted bovine trichomoniasis and campylobacteriosis affecting cattle reproductive health.

    PubMed

    Michi, Aubrey N; Favetto, Pedro H; Kastelic, John; Cobo, Eduardo R

    2016-03-15

    The objective is to discuss sexually transmitted diseases caused by Tritrichomonas foetus (T foetus) and Campylobacter fetus (C fetus) subsp. venerealis, with a focus on prevalence, pathogenesis, and diagnosis in cows and bulls. Diagnosis and control are problematic because these diseases cause severe reproductive losses in cows, but in bulls are clinically asymptomatic, which allows the disease to flourish, especially in the absence of legislated control programs. We review research regarding prophylactic systemic immunization of bulls and cows with antigens of T foetus and C fetus venerealis and their efficacy in preventing or clearing preexisting infections in the genital tract. Current diagnostic methods of C fetus venerealis and T foetus (microbial culture and PCR) should be improved. Review of the latest advances in bovine trichomoniasis and campylobacteriosis should promote knowledge and provide an impetus to pursue further efforts to control bovine sexually transmitted diseases.

  11. Reproductive traits affect the rescue of valuable and endangered multipurpose tropical trees.

    PubMed

    Sinébou, Viviane; Quinet, Muriel; Ahohuendo, Bonaventure C; Jacquemart, Anne-Laure

    2016-01-01

    Conservation strategies are urgently needed in Tropical areas for widely used tree species. Increasing numbers of species are threatened by overexploitation and their recovery might be poor due to low reproductive success and poor regeneration rates. One of the first steps in developing any conservation policy should be an assessment of the reproductive biology of species that are threatened by overexploitation. This work aimed to study the flowering biology, pollination and breeding system of V. doniana, a multipurpose threatened African tree, as one step in assessing the development of successful conservation strategies. To this end, we studied (1) traits directly involved in pollinator attraction like flowering phenology, flower numbers and morphology, and floral rewards; (2) abundance, diversity and efficiency of flower visitors; (3) breeding system, through controlled hand-pollination experiments involving exclusion of pollinators and pollen from different sources; and (4) optimal conditions for seed germination. The flowering phenology was asynchronous among inflorescences, trees and sites. The flowers produced a large quantity of pollen and nectar with high sugar content. Flowers attracted diverse and abundant visitors, counting both insects and birds, and efficient pollinators included several Hymenoptera species. We detected no spontaneous self-pollination, indicating a total dependence on pollen vectors. Vitex doniana is self-compatible and no inbreeding depression occurred in the first developmental stages. After extraction of the seed from the fruit, seed germination did not require any particular conditions or pre-treatments and the seeds showed high germination rates. These pollination and breeding characteristics as well as germination potential offer the required conditions to develop successful conservation strategies. Protection, cultivation and integration in agroforestry systems are required to improve the regeneration of the tree.

  12. Off-road vehicles affect nesting behaviour and reproductive success of American Oystercatchers Haematopus palliatus

    USGS Publications Warehouse

    Borneman, Tracy E.; Rose, Eli T.; Simons, Theodore R.

    2016-01-01

    As human populations and associated development increase, interactions between humans and wildlife are occurring with greater frequency. The effects of these interactions, particularly on species whose populations are declining, are of great interest to ecologists, conservationists, land managers and natural resource policy-makers. The American Oystercatcher Haematopus palliatus, a species of conservation concern in the USA, nests on coastal beaches subject to various forms of anthropogenic disturbance, including aircraft overflights, off-road vehicles and pedestrians. This study assessed the effects of these human disturbances on the incubation behaviour and reproductive success of nesting American Oystercatchers at Cape Lookout National Seashore, on the Atlantic coast of the USA. We expanded on-going monitoring of Oystercatchers at Cape Lookout National Seashore by supplementing periodic visual observations with continuous 24-h video and audio recording at nests. Aircraft overflights were not associated with changes in Oystercatcher incubation behaviour, and we found no evidence that aircraft overflights influenced Oystercatcher reproductive success. However, Oystercatchers were on their nests significantly less often during off-road vehicle and pedestrian events than they were during control periods before the events, and an increase in the number of off-road vehicles passing a nest during incubation was consistently associated with significant reductions in daily nest survival (6% decrease in daily nest survival for a one-vehicle increase in the average number of vehicles passing a nest each day; odds ratio = 0.94; 95% confidence interval (CI) 0.90, 0.98) and hatching success (12% decrease in hatching success for a one-vehicle increase in the average number of vehicles passing a nest each day; odds ratio = 0.88; 95% CI 0.76, 0.97). Management of vehicles and pedestrians in areas of Oystercatcher breeding is important for the conservation of American

  13. Reproductive traits affect the rescue of valuable and endangered multipurpose tropical trees

    PubMed Central

    Sinébou, Viviane; Quinet, Muriel; Ahohuendo, Bonaventure C.; Jacquemart, Anne-Laure

    2016-01-01

    Conservation strategies are urgently needed in Tropical areas for widely used tree species. Increasing numbers of species are threatened by overexploitation and their recovery might be poor due to low reproductive success and poor regeneration rates. One of the first steps in developing any conservation policy should be an assessment of the reproductive biology of species that are threatened by overexploitation. This work aimed to study the flowering biology, pollination and breeding system of V. doniana, a multipurpose threatened African tree, as one step in assessing the development of successful conservation strategies. To this end, we studied (1) traits directly involved in pollinator attraction like flowering phenology, flower numbers and morphology, and floral rewards; (2) abundance, diversity and efficiency of flower visitors; (3) breeding system, through controlled hand-pollination experiments involving exclusion of pollinators and pollen from different sources; and (4) optimal conditions for seed germination. The flowering phenology was asynchronous among inflorescences, trees and sites. The flowers produced a large quantity of pollen and nectar with high sugar content. Flowers attracted diverse and abundant visitors, counting both insects and birds, and efficient pollinators included several Hymenoptera species. We detected no spontaneous self-pollination, indicating a total dependence on pollen vectors. Vitex doniana is self-compatible and no inbreeding depression occurred in the first developmental stages. After extraction of the seed from the fruit, seed germination did not require any particular conditions or pre-treatments and the seeds showed high germination rates. These pollination and breeding characteristics as well as germination potential offer the required conditions to develop successful conservation strategies. Protection, cultivation and integration in agroforestry systems are required to improve the regeneration of the tree. PMID:27354660

  14. Knowing your audience affects male-male interactions in Siamese fighting fish (Betta splendens).

    PubMed

    Bertucci, Frédéric; Matos, Ricardo J; Dabelsteen, Torben

    2014-03-01

    Aggressive interactions between animals often occur in the presence of third parties. By observing aggressive signalling interactions, bystanders may eavesdrop and gain relevant information about conspecifics without the costs of interacting. On the other hand, interactants may also adjust their behaviour when an audience is present. This study aimed to test how knowledge about fighting ability of an audience affects aggressive interactions in male Siamese fighting fish. Subjects were positioned between two dyads of non-interacting males and allowed to observe both dyads shortly before the view to one of the dyads was blocked, and the dyads were allowed to interact. Subjects were subsequently exposed to an unknown opponent in the presence of either the winner or the loser of the seen or unseen interaction. The results suggest a complex role of the characteristic of an audience in the agonistic behaviours of a subject engaged in an interaction. The presence of a seen audience elicited more aggressive displays towards the opponent if the audience was a loser. This response was different in the presence of an unseen audience. Subjects then directed a higher aggressiveness against their opponent if the audience was a winner. These results also suggest a potentially more complex and interesting process allowing individuals to gain information about the quality and threat level of an unknown audience while it is interacting with a third party. The importance of information acquisition for an individual to adapt its behaviour and the role of communication networks in shaping social interactions are discussed.

  15. Homogenization conditions affect the oxidative stability of fish oil enriched milk emulsions: lipid oxidation.

    PubMed

    Let, Mette B; Jacobsen, Charlotte; Sørensen, Ann-Dorit M; Meyer, Anne S

    2007-03-07

    In this study fish oil was incorporated into commercial homogenized milk using different homogenization temperatures and pressures. The main aim was to understand the significance of homogenization temperature and pressure on the oxidative stability of the resulting milks. Increasing homogenization temperature from 50 to 72 degrees C decreased droplet size only slightly, whereas a pressure increase from 5 to 22.5 MPa decreased droplet size significantly. Surprisingly, emulsions having small droplets, and therefore large interfacial area, were less oxidized than emulsions having bigger droplets. Emulsions with similar droplet size distributions, but resulting from different homogenization conditions, had significantly different oxidative stabilities, indicating that properties of significance to oxidation other than droplet size itself were affected by the different treatments. In general, homogenization at 72 degrees C appeared to induce protective effects against oxidation as compared to homogenization at 50 degrees C. The results thus indicated that the actual composition of the oil-water interface is more important than total surface area itself.

  16. Predator density and timing of arrival affect reef fish community assembly.

    PubMed

    Stier, Adrian C; Geange, Shane W; Hanson, Kate M; Bolker, Benjamin M

    2013-05-01

    Most empirical studies of predation use simple experimental approaches to quantify the effects of predators on prey (e.g., using constant densities of predators, such as ambient vs. zero). However, predator densities vary in time, and these effects may not be well represented by studies that use constant predator densities. Although studies have independently examined the importance of predator density, temporal variability, and timing of arrival (i.e., early or late relative to prey), the relative contribution of these different predator regimes on prey abundance, diversity, and composition remains poorly understood. The hawkfish (Paracirrhites arcatus), a carnivorous coral reef fish, exhibits substantial variability in patch occupancy, density, and timing of arrival to natural reefs. Our field experiments demonstrated that effects of hawkfish on prey abundance depended on both hawkfish density and the timing of their arrival, but not on variability in hawkfish density. Relative to treatments without hawkfish, hawkfish presence reduced prey abundance by 50%. This effect increased with a doubling of hawkfish density (an additional 33% reduction), and when hawkfish arrived later during community development (a 34% reduction). Hawkfish did not affect within-patch diversity (species richness), but they increased between-patch diversity (beta) based on species incidence (22%), and caused shifts in species composition. Our results suggest that the timing of predator arrival can be as important as predator density in modifying prey abundance and community composition.

  17. Fish functional traits are affected by hydrodynamics at small spatial scale.

    PubMed

    Bracciali, C; Guzzo, G; Giacoma, C; Dean, J M; Sarà, G

    2016-02-01

    The Mediterranean damselfish Chromis chromis is a species with a broad distribution found both in the Mediterranean Sea and Eastern Atlantic as far south as the coast of Angola. We hypothesized that the species may have significant functional morphological plasticity to adapt along a gradient of environmental conditions. It is a non-migratory zooplanktivorous species and spends the daytime searching for food in the middle of the water column. Therefore, local hydrodynamics could be one of the environmental factors affecting traits of C. chromis with repercussions at the population level. We compared the body condition, individual growth and body shapes of damselfish collected under two different hydrodynamic conditions (low ∼10 cm s(-1) vs. high ∼20 cm s(-1)). Specimens showed higher body condition under high-hydrodynamics, where conditions offered greater amounts of food, which were able to support larger individuals. Individuals smaller than 60-mm were more abundant under low-hydrodynamics. Morphometric analysis revealed that high-hydrodynamics were favored by fish with a more fusiform body shape and body traits developed for propellant swimming.

  18. Social competition affects electric signal plasticity and steroid levels in the gymnotiform fish Brachyhypopomus gauderio.

    PubMed

    Salazar, Vielka L; Stoddard, Philip K

    2009-10-01

    Sexually-selected communication signals can be used by competing males to settle contests without incurring the costs of fighting. Steroid regulation of these signals can render them as reliable indicators of a male's physiological state. We investigated how plasticity in electrocommunication signals is driven by social competition for mates, mediated by steroid hormones, and subject to the effects of past social experience. We measured the electric waveform's amplitude and duration and steroid hormone levels of male gymnotiform electric fish (Brachyhypopomus gauderio) following week-long periods of social isolation, and low or high social competition. To quantify the effect of social history on the modulation of the electric signal, six groups of six males experienced all three social conditions but in different order. We found that males differentially modulate their electric signals depending on the order they experienced these conditions. Thus, past social interactions affect both present and future social electric signals. Cortisol levels and the amplitude of the electric signal appeared to track the intensity of competition, while androgen levels and the duration of the electric signal only responded to the presence (low and high competition) or absence (isolation) of a social environment (low and high androgens respectively). In addition, cortisol levels were related to the body size of the males at high social competition. Taken together, these findings suggest that the capacity of males to modulate their signals in response to social competition is regulated by steroids.

  19. Technical issues affecting the implementation of US Environmental Protection Agency's proposed fish tissue-based aquatic criterion for selenium.

    PubMed

    Lemly, A Dennis; Skorupa, Joseph P

    2007-10-01

    The US Environmental Protection Agency is developing a national water quality criterion for selenium that is based on concentrations of the element in fish tissue. Although this approach offers advantages over the current water-based regulations, it also presents new challenges with respect to implementation. A comprehensive protocol that answers the "what, where, and when" is essential with the new tissue-based approach in order to ensure proper acquisition of data that apply to the criterion. Dischargers will need to understand selenium transport, cycling, and bioaccumulation in order to effectively monitor for the criterion and, if necessary, develop site-specific standards. This paper discusses 11 key issues that affect the implementation of a tissue-based criterion, ranging from the selection of fish species to the importance of hydrological units in the sampling design. It also outlines a strategy that incorporates both water column and tissue-based approaches. A national generic safety-net water criterion could be combined with a fish tissue-based criterion for site-specific implementation. For the majority of waters nationwide, National Pollution Discharge Elimination System permitting and other activities associated with the Clean Water Act could continue without the increased expense of sampling and interpreting biological materials. Dischargers would do biotic sampling intermittently (not a routine monitoring burden) on fish tissue relative to the fish tissue criterion. Only when the fish tissue criterion is exceeded would a full site-specific analysis including development of intermedia translation factors be necessary.

  20. Does interspecies hybridization affect the host specificity of parasites in cyprinid fish?

    PubMed Central

    2013-01-01

    Background Host specificity varies among parasite species. Some parasites are strictly host-specific, others show a specificity for congeneric or non-congeneric phylogenetically related host species, whilst some others are non-specific (generalists). Two cyprinids, Cyprinus carpio and Carassius gibelio, plus their respective hybrids were investigated for metazoan parasites. The aim of this study was to analyze whether interspecies hybridization affects host specificity. The different degrees of host specificity within a phylogenetic framework were taken into consideration (i.e. strict specialist, intermediate specialist, and intermediate generalist). Methods Fish were collected during harvesting the pond and identified using meristic traits and molecular markers. Metazoan parasite species were collected. Host specificity of parasites was determined using the following classification: strict specialist, intermediate specialist, intermediate generalist and generalist. Parasite species richness was compared between parental species and their hybrids. The effect of host species on abundance of parasites differing in host specificity was tested. Results Hybrids harbored more different parasite species but their total parasite abundance was lower in comparison with parental species. Interspecies hybridization affected the host specificity of ecto- and endoparasites. Parasite species exhibiting different degrees of host specificity for C. carpio and C. gibelio were also present in hybrids. The abundance of strict specialists of C. carpio was significantly higher in parental species than in hybrids. Intermediate generalists parasitizing C. carpio and C. gibelio as two phylogenetically closely related host species preferentially infected C. gibelio when compared to C. carpio, based on prevalence and maximum intensity of infection. Hybrids were less infected by intermediate generalists when compared to C. gibelio. Conclusions This finding does not support strict co

  1. Fish oil supplementation decreases oxidative stress but does not affect platelet-activating factor bioactivity in lungs of asthmatic rats.

    PubMed

    Zanatta, A L; Miranda, D T S Z; Dias, B C L; Campos, R M; Massaro, M C; Michelotto, P V; West, A L; Miles, E A; Calder, P C; Nishiyama, A

    2014-07-01

    Dietary fish oil supplementation increases the content of n-3 polyunsaturated fatty acids (PUFA) in cellular membranes. The highly unsaturated nature of n-3 PUFA could result in an enhanced lipid peroxidation in the oxidative environment characteristic of asthma. The oxidative reaction cascade culminates in an increased production of components associated to oxidative stress and of an important proinflammatory mediator platelet-activating factor (PAF)-like lipid. We evaluated the effect of fish oil supplementation in asthmatic rats upon the PAF bioactivity and parameters related to oxidative stress in the lung. Fish oil supplementation of asthmatic rats resulted in lower concentrations of nitrite (1.719 ± 0.137 vs. 2.454 ± 0.163 nmol/mL) and lipid hydroperoxide (72.190 ± 7.327 vs. 120.200 ± 11.270 nmol/mg protein). In asthmatic animals, fish oil increased the activities of superoxide dismutase (EC 1.15.1.1) (33.910 ± 2.325 vs. 24.110 ± 0.618 U/mg protein) and glutathione peroxidase (EC 1.11.1.9) (164.100 ± 31.250 vs. 12.590 ± 5.234 U/mg protein). However, fish oil did not affect PAF bioactivity in lung tissue of asthmatic rats (0.545 ± 0.098 340/380 vs. 0.669 ± 0.101 340/380 nm ratio). Considering the two-step process--oxidative stress and PAF bioactivity--fish oil exhibited a divergent action on these aspects of asthmatic inflammation, since the supplement lowered oxidative stress in the lungs of asthmatic rats, presenting an antioxidant effect, but did not affect PAF bioactivity. This suggests a dual effect of fish oil on oxidative stress and inflammation in asthma.

  2. Low temperature affects cattle tick reproduction but does not lead to transovarial transmission of Anaplasma marginale.

    PubMed

    Esteves, E; Pohl, P C; Klafke, G M; Reck, J; Fogaça, A C; Martins, J R; Daffre, S

    2015-12-15

    Anaplasma marginale is an obligate intracellular pathogen that infects the erythrocytes of calves, causing bovine anaplasmosis. This rickettsia is biologically transmitted by several species of ticks. In tropical and subtropical regions of the world, Rhipicephalus microplus is the main vector. Due to their mobility and longevity, the adult males play an important role in the transmission of A. marginale to calves. Some studies have demonstrated that A. marginale can be intrastadially and interstadially transmitted in R. microplus, but the transovarial transmission has not been demonstrated so far. In the present study, we investigated the effects of low temperature on both the A. marginale migration from infected females to their offspring and reproductive parameters of the tick R. microplus. The larvae of R. microplus fed on a calf infected with the strain Jaboticabal of A. marginale. At the end of the parasitic phase, fully engorged females were incubated at either 18°C or 28°C for oviposition. Although A. marginale was detected in the salivary glands of the females, demonstrating that the ticks were successfully infected, the presence of rickettsia was not detected in the offspring. However, the preoviposition period of the non-infected females maintained at 18°C was longer than that of those maintained at 28°C. In addition, the average weight of the mass of eggs as well as the egg production efficiency (ratio of the egg mass weight to the female weight) of the females maintained at 18°C were significantly lower than those of the females incubated at 28°C. There was no larval hatching from the eggs maintained exclusively at 18°C, even at 65 days after female detachment. Hatching occurred only when the eggs maintained at 18°C were transferred to 28°C at 20 days after female detachment (18°C/28°C). We also verified a significantly higher larvae conversion efficiency (ratio of the larvae mass weight to the egg mass weight) in the group of females

  3. CO2, Temperature, and Soil Moisture Interactions Affect NDVI and Reproductive Phenology in Old-Field Plant Communities

    NASA Astrophysics Data System (ADS)

    Engel, C.; Weltzin, J.; Norby, R.

    2004-12-01

    Plant community composition and ecosystem function may be altered by global atmospheric and climate change, including increased atmospheric [CO2], temperature, and varying precipitation regimes. We are conducting an experiment at Oak Ridge National Laboratory (ORNL) utilizing open-top chambers to administer experimental treatments of elevated CO2 (+300 ppm), warming (+ 3 degrees Celsius), and varying soil moisture availability to experimental plant communities constructed of seven common old-field species, including C3 and C4 grasses, forbs, and legumes. During 2004 we monitored plant community phenology (NDVI) and plant reproductive phenology. Early in the year, NDVI was greater in wet treatment plots, and was unaffected by main effects of temperature or CO2. This result suggests that early in the season warming is insufficient to affect early canopy development. Differences in soil moisture sustained throughout the winter and into early spring may constitute an important control on early canopy greenup. Elevated CO2 alleviated detrimental effects of warming on NDVI, but only early in the season. As ambient temperatures increased, elevated temperatures negatively impacted NDVI only in the dry plots. Wetter conditions ameliorate the effects of warming on canopy greenness during the warmer seasons of the year. Warming increased rates of bolting, number of inflorescences, and time to reproductive maturity for Andropogon virginicus (a C4 bunchgrass). Solidago Canadensis (a C3 late-season forb) also produced flowers earlier in elevated temperatures. Conversely, none of the C3 grasses and forbs that bolt or flower in late spring or early summer responded to temperature or CO2. Results indicate that warming and drought may impact plant community phenology, and plant species reproductive phenology. Clearly community phenology is driven by complex interactions among temperature, water, and CO2 that change throughout the season. Our data stresses the importance of

  4. How the magnitude of clinical severity and recurrence risk affects reproductive decisions in adult males with different forms of progressive muscular dystrophy.

    PubMed Central

    Eggers, S; Zatz, M

    1998-01-01

    The reproductive history of 177 male patients affected with Becker (BMD) (n=69), limb-girdle (LGMD) (n=54), and facioscapulohumeral (FSHMD) (n=54) muscular dystrophy (MD) was analysed according to severity of the disease (BMD>LGMD>FSHMD) and magnitude of recurrence risk (RR) (high for FSHMD, intermediate for BMD, and low for LGMD). Additionally, 62 male patients were interviewed on psychosocial issues, in order to disentangle the factors influencing reproductive decisions among patients affected with MD. Among male adults, significantly more FSHMD than LGMD or BMD patients were married and had children. Age specific reproductive outcome was 0.31-0.32 for BMD, 0.51-0.62 for LGMD, and 0.58-1.02 for FSHMD, reflecting the influence of the disease's severity. High RRs did not significantly diminish reproduction after genetic counselling or correlate with less prospective desire for children. Instead, early onset, severity of the disease, and past reproductive history were found to diminish reproductive outcome after genetic counselling, and prospective family planning was also found to be influenced by past reproductive history as well as by emotional/sexual dysfunction with the opposite sex. PMID:9541101

  5. How the magnitude of clinical severity and recurrence risk affects reproductive decisions in adult males with different forms of progressive muscular dystrophy.

    PubMed

    Eggers, S; Zatz, M

    1998-03-01

    The reproductive history of 177 male patients affected with Becker (BMD) (n=69), limb-girdle (LGMD) (n=54), and facioscapulohumeral (FSHMD) (n=54) muscular dystrophy (MD) was analysed according to severity of the disease (BMD>LGMD>FSHMD) and magnitude of recurrence risk (RR) (high for FSHMD, intermediate for BMD, and low for LGMD). Additionally, 62 male patients were interviewed on psychosocial issues, in order to disentangle the factors influencing reproductive decisions among patients affected with MD. Among male adults, significantly more FSHMD than LGMD or BMD patients were married and had children. Age specific reproductive outcome was 0.31-0.32 for BMD, 0.51-0.62 for LGMD, and 0.58-1.02 for FSHMD, reflecting the influence of the disease's severity. High RRs did not significantly diminish reproduction after genetic counselling or correlate with less prospective desire for children. Instead, early onset, severity of the disease, and past reproductive history were found to diminish reproductive outcome after genetic counselling, and prospective family planning was also found to be influenced by past reproductive history as well as by emotional/sexual dysfunction with the opposite sex.

  6. Factors Affecting the Reproduction, Recruitment, Habitat, and Population Dynamics of Pallid Sturgeon and Shovelnose Sturgeon in the Missouri River

    USGS Publications Warehouse

    Korschgen, Carl E.

    2007-01-01

    For more than a hundred years, human activities have modified the natural forces that control the Missouri River and its native fish fauna. While the ecological effects of regulation and channel engineering are understood in general, the current understanding is not sufficient to guide river restoration and management. The U.S. Geological Survey (USGS) is in the third year of a multiagency research effort to determine the ecological requirements for reproduction and survival of the endangered pallid sturgeon (Scaphirhynchus albus) and shovelnose sturgeon (Scaphirhynchus platorhynchus) in the Missouri River. The multidisciplinary research strategy includes components of behavior, physiology, habitat use, habitat availability, and population modeling of all life stages. Shovelnose sturgeon are used to design the strategy because they are closely related to the pallid sturgeon and are often used as a surrogate species to develop new research tools or to examine the effects of management actions or environmental variables on sturgeon biology and habitat use. During fiscal years 2005 and 2006, the U.S. Army Corps of Engineers (USACE) provided funds to USGS for tasks associated with the Comprehensive Sturgeon Research Program (CSRP) and for tasks associated with evaluation of the Sturgeon Response to Flow Modifications (SRFM). Because work activities of CSRP and SRFM are so integrated, we are providing information on activities that have been consolidated at the task level. These task activities represent chapters in this report.

  7. Does cadmium pollution affect reproduction in the clam Ruditapes decussatus? A one-year case study.

    PubMed

    Smaoui-Damak, W; Rebai, T; Berthet, B; Hamza-Chaffai, A

    2006-06-01

    The effect of cadmium (Cd) on the reproduction of Ruditapes decussatus was monitored over a period of 12 months, from June 2001 to June 2002. Two sites "Bordj d'Ungha" and "El Hofra" differing by their degree of cadmium contamination were chosen in the Gulf of Gabès area (Tunisia). Annual mean concentrations of Cd in the whole soft tissues of clams from the site El Hofra were more than 4 times higher than those from the site Bordj d'Ungha (reference site). The gametogenic cycle of the clam R. decussatus was also investigated by histological examination and monthly observations of gonadal sections in a population of clams from both sites. The results show that gametogenesis occurred from March to December in clams from both sites. Nevertheless, spawning and emission of gametes were synchronized in both sexes from only the clams of the reference site. Although this species is considered as gonochoristic, 6.6% of hermaphroditic cases were observed in clams from both sites in which gametes of both males and females were in ripe stage. Moreover, the period of ripening of sexual products led to an increase of condition index and to a decrease of Cd concentrations in the whole soft tissues of clams from both sites, hence reflecting the phenomenon of "biological dilution".

  8. Invasion of Tomato Roots and Reproduction of Meloidogyne incognita as Affected by Raw Sewage Sludge

    PubMed Central

    Castagnone-Sereno, Philippe; Kermarrec, Alain

    1991-01-01

    The antagonistic effects of raw sewage sludge on infection of tomato by Meloidogyne incognita were tested in greenhouse pot experiments. Sludge was mixed with the soil or added on its surface before and after inoculation of tomato plants with nematode eggs. Juvenile penetration was determined 1 and 10 days after inoculation, and 6 weeks later root systems were assessed for nematode reproduction. Fewer juveniles penetrated roots in pots with sludge added to the soil than in unamended control pots. In both experiments, roots were severely galled despite a significant reduction in gall ratings in amended relative to unamended soils. Egg production in treated soil was less (P = 0.05) than in control pots, regardless of whether sludge was incorporated or added 1 day before or after inoculation. In treated pots, RF values (final egg number/inoculation egg number) were strongly reduced. The toxic effects observed on the parasite may result from the ammoniacal nitrogen released in the soil within 7 days after treatment, associated with possible poor host suitability of tomatoes grown in amended substrate and short-lasting compound(s) active after root invasion. PMID:19283192

  9. Floral scents affect reproductive success in fly-pollinated Alocasia odora (Araceae).

    PubMed

    Miyake, Takashi; Yafuso, Masako

    2003-03-01

    We evaluated the role of floral scents in the reproductive success of Alocasia odora C. Koch (Araceae). Alocasia odora is pollinated by its specific pollinators, Colocasiomyia alocasiae (Okada) and C. xenalocasiae (Okada) (Diptera: Drosophilidae). These flies use the spadix of A. odora as breeding sites. The appendix, which is at an upper part of the spadix and is the most attractive region, attracted these pollinators by emitting volatiles, although the male zone of the inflorescence was also attractive. The number of flies attracted was positively correlated with appendix size. During the pistillate phase of the protogynous spadix, attracted flies aggregated in the lower part (female zone) to mate, lay eggs, and perhaps obtain nutrients. The flies moved to the upper part (male zone) of the spadix by the tightening of the constriction separating the upper and lower parts, and then the staminate phase started. This movement of the flies on the spadix promotes outcrossing of A. odora. Removal of the appendix or the whole upper part of the spadix resulted in much reduced fruit set, suggesting that the absence of the scent-producing region leads to insufficient pollination because of reduced pollinator attraction.

  10. Flows, droughts, and aliens: factors affecting the fish assemblage in a Sierra Nevada, California, stream.

    PubMed

    Kiernan, Joseph D; Moyle, Peter B

    2012-06-01

    The fishes of Martis Creek, in the Sierra Nevada of California (USA), were sampled at four sites annually over 30 years, 1979-2008. This long-term data set was used to examine (1) the persistence and stability of the Martis Creek fish assemblage in the face of environmental stochasticity; (2) whether native and alien fishes responded differently to a natural hydrologic regime (e.g., timing and magnitude of high and low flows); and (3) the importance of various hydrologic and physical habitat variables in explaining the abundances of native and alien fish species through time. Our results showed that fish assemblages were persistent at all sample sites, but individual species exhibited marked interannual variability in density, biomass, and relative abundance. The density and biomass of native fishes generally declined over the period of study, whereas most alien species showed no significant long-term trends. Only alien rainbow trout increased in both density and biomass at all sites over time. Redundancy analysis identified three hydrologic variables (annual 7-day minimum discharge, maximum winter discharge, and number of distinct winter floods) and two habitat variables (percentage of pool habitat and percentage of gravel substrate) that each explained a significant portion of the annual variation in fish assemblage structure. For alien taxa, their proportional contribution to the total fish assemblage was inversely related to mean annual streamflow, one-day maximum discharge in both winter and spring, and the frequency of springtime floods. Results of this study highlight the need for continuous annual monitoring of streams with highly variable flow regimes to evaluate shifts in fish community structure. Apparent successes or failures in stream management may appear differently depending on the time series of available data.

  11. Generation of a specific immunological response to FGF-2 does not affect wound healing or reproduction.

    PubMed

    Plum, Stacy M; Vu, Hong A; Mercer, Bobby; Fogler, William E; Fortier, Anne H

    2004-02-01

    Angiogenesis, the process of new capillary formation from pre-existing vessels, has been established as an important mechanism involved in pathologic processes, such as cancer, as well as in normal physiology (Ribatti, D.; Vacca, A.; Roncali, L.; Dammacco, F. Angiogenesis under normal and pathological conditions. Haematologica 1991, 76 (4), 311-320). Basic fibroblast growth factor (FGF-2) is a critical mediator of angiogenesis that is important for normal reproduction and wound healing. FGF-2 mediates its pro-angiogenic effects by binding to heparin sulfate proteoglycan in addition to a tyrosine kinase receptor (Baird, A.; Schubert, D.; Ling, N.; Guillemin, R. Receptor and heparin-binding domain of basic fibroblast growth factor. Proc. Natl. Acad. Sci. U. S. A. 1998, 5 (7), 2324-2328; Richard, C.; Roghani, M.; Moscatelli, D. Fibroblast growth factor (FGF)-2 mediates cell attachment through interactions with two FGF receptor-1 isoforms and extracellular matrix or cell-associated heparin sulfate proteoglycans. Biochem. Biophys. Res. Commun. 2000, 276 (2), 399-405; Casu, B.; Guerrini, M.; Naggi, A.; Perez, M.; Torri, G.; Ribatti, D.; Carminati, P.; Giannini, G.; Penco, S.; Pisano, C.; Belleri, M.; Rusnati, M.; Presta, M. Short heparin sequences spaced by glycol-split urinate residues are antagonists of fibroblast growth factor 2 and angiogenesis inhibitors. Biochemistry 2002, 41 (33), 10519-10528; Murphy, P.V.; Pitt, N.; O'Brien, A.; Enright, P.M.; Dunne, A.; Wilson, S.J.; Duane, R.M.; O'Boyle, K.M. Identification of novel inhibitors of fibroblast growth factor (FGF-2) binding to heparin and endothelial cell survival from a structurally diverse carbohybrid library. Bioorg. Med. Chem. Lett. 2002, 12 (22), 3287-3290). We developed a liposomal-based peptide vaccine, L(HBD) that targets the heparin binding domain of the FGF-2 molecule. This vaccine, when inoculated into mice, inhibits angiogenesis in response to FGF-2 in a hepatic sponge model as well as tumor progression

  12. Developmental methoxychlor exposure affects multiple reproductive parameters and ovarian folliculogenesis and gene expression in adult rats

    SciTech Connect

    Armenti, AnnMarie E.; Zama, Aparna Mahakali; Passantino, Lisa; Uzumcu, Mehmet

    2008-12-01

    Methoxychlor (MXC) is an organochlorine pesticide with estrogenic, anti-estrogenic, and anti-androgenic properties. To investigate whether transient developmental exposure to MXC could cause adult ovarian dysfunction, we exposed Fischer rats to 20 {mu}g/kg/day (low dose; environmentally relevant dose) or 100 mg/kg/day (high dose) MXC between 19 days post coitum and postnatal day 7. Multiple reproductive parameters, serum hormone levels, and ovarian morphology and molecular markers were examined from prepubertal through adult stages. High dose MXC accelerated pubertal onset and first estrus, reduced litter size, and increased irregular cyclicity (P < 0.05). MXC reduced superovulatory response to exogenous gonadotropins in prepubertal females (P < 0.05). Rats exposed to high dose MXC had increasing irregular estrous cyclicity beginning at 4 months of age, with all animals showing abnormal cycles by 6 months. High dose MXC reduced serum progesterone, but increased luteinizing hormone (LH). Follicular composition analysis revealed an increase in the percentage of preantral and early antral follicles and a reduction in the percentage of corpora lutea in high dose MXC-treated ovaries (P < 0.05). Immunohistochemical staining and quantification of the staining intensity showed that estrogen receptor {beta} was reduced by high dose MXC while anti-Mullerian hormone was upregulated by both low- and high dose MXC in preantral and early antral follicles (P < 0.05). High dose MXC significantly reduced LH receptor expression in large antral follicles (P < 0.01), and down-regulated cytochrome P450 side-chain cleavage. These results demonstrated that developmental MXC exposure results in reduced ovulation and fertility and premature aging, possibly by altering ovarian gene expression and folliculogenesis.

  13. Male age is not an independent factor to affect the outcome of assisted reproductive techniques.

    PubMed

    Kumtepe, Yakup; Yakin, Kayhan; Kahraman, Semra; Sertyel, Semra; Vanlioğlu, Faruk; Cengiz, Sami; Dönmez, Ersan

    2003-06-01

    Controversy exists whether advanced male age is associated with poor sperm quality and subsequent failure in the assisted reproductive techniques (ART). The purpose of this study was to evaluate the effect of male age on sperm quality and the outcome of ART as well as the association of male age with other relevant factors, particularly with the female age. A retrospective study was performed in order to evaluate the effect of male age on the sperm parameters in 880 routine seminal analyses. Additionally, sperm parameters were also compared among different age groups in 919 cases with male factor infertility who had been included in an ART programme. The laboratory and clinical results of ART (fertilization rate, number and quality of embryos transferred, as well as pregnancy rates) were compared according to different age groups. The results were also evaluated by one-way correlation and also step-wise logistic regression analysis to identify the interactions and correlations between different parameters. There were no statistically significant differences between male age groups in terms of sperm concentration, motility and morphology either in routine seminal analyses or in ART groups. In the ART group, a statistically significant linear correlation was present between male and female ages. Male age was increasing in parallel to female age. Female age was also correlated significantly with ART results. In one-way correlation analysis, male age was found to be correlated with the pregnancy rate, but not with fertilization rate and the quality of the transferred embryos. However, regression analysis revealed that correlation between male age and pregnancy results was simply dependent on the effect of the female age. Seminal parameters did not reveal a significant change with the increasing male age. The effect of male age on ART results in cases with male factor infertility is not a direct effect but a reflection of the negative impact of the parallel increase in

  14. Aboveground Feeding by Soybean Aphid, Aphis glycines, Affects Soybean Cyst Nematode, Heterodera glycines, Reproduction Belowground

    PubMed Central

    McCarville, Michael T.; Soh, David H.; Tylka, Gregory L.; O’Neal, Matthew E.

    2014-01-01

    Heterodera glycines is a cyst nematode that causes significant lost soybean yield in the U.S. Recent studies observed the aphid Aphis glycines and H. glycines interacting via their shared host, soybean, Glycine max. A greenhouse experiment was conducted to discern the effect of A. glycines feeding on H. glycines reproduction. An H. glycines-susceptible cultivar, Kenwood 94, and a resistant cultivar, Dekalb 27–52, were grown in H. glycines-infested soil for 30 and 60 d. Ten days after planting, plants were infested with either zero, five, or ten aphids. At 30 and 60 d, the number of H. glycines females and cysts (dead females) and the number of eggs within were counted. In general, H. glycines were less abundant on the resistant than the susceptible cultivar, and H. glycines abundance increased from 30 to 60 d. At 30 d, 33% more H. glycines females and eggs were produced on the resistant cultivar in the ten-aphid treatment compared to the zero-aphid treatment. However, at 30 d the susceptible cultivar had 50% fewer H. glycines females and eggs when infested with ten aphids. At 60 d, numbers of H. glycines females and cysts and numbers of eggs on the resistant cultivar were unaffected by A. glycines feeding, while numbers of both were decreased by A. glycines on the susceptible cultivar. These results indicate that A. glycines feeding improves the quality of soybean as a host for H. glycines, but at higher herbivore population densities, this effect is offset by a decrease in resource quantity. PMID:24466080

  15. Do method and species lifestyle affect measures of maximum metabolic rate in fishes?

    PubMed

    Killen, S S; Norin, T; Halsey, L G

    2017-03-01

    The rate at which active animals can expend energy is limited by their maximum aerobic metabolic rate (MMR). Two methods are commonly used to estimate MMR as oxygen uptake in fishes, namely during prolonged swimming or immediately following brief exhaustive exercise, but it is unclear whether they return different estimates of MMR or whether their effectiveness for estimating MMR varies among species with different lifestyles. A broad comparative analysis of MMR data from 121 fish species revealed little evidence of different results between the two methods, either for fishes in general or for species of benthic, benthopelagic or pelagic lifestyles.

  16. Epizootic ulcerative syndrome affecting fish in the Zambezi river system in southern Africa.

    PubMed

    Andrew, T G; Huchzermeyer, K D A; Mbeha, B C; Nengu, S M

    2008-11-22

    In late 2006, diseased fish of a variety of species began to appear in the Chobe and upper Zambezi rivers in southern Africa. In April 2007, investigations showed that the levels of pesticides and heavy metals in the tissues of the fish were very low, discounting pollution as an underlying cause for the disease. However, histological evidence showed that the disease closely resembled the epizootic ulcerative syndrome caused by the oomycete Aphanomyces invadans, a serious aquatic pathogen that has been isolated from freshwater and estuarine fish in Japan, south-east Asia, Australia and the usa since the 1970s, but not previously recorded in Africa.

  17. Fish bioturbation of cadmium-contaminated sediments: Factors affecting Cd availability to Daphnia magna

    SciTech Connect

    Wall, S.B.; La Point, T.W.; Isely, J.J.

    1996-03-01

    Benthic fish bioturbation of contaminated sediments is thought to enhance exposure and, potentially, bioaccumulation into planktonic organisms. Exposures were conducted with cadmium-spiked sediment, 1.0 mg/kg nominal concentrations, and koi carp (Cyprinus carpio). Daphnia magna were placed in aquaria with and without fish for 6 d and Cd bioaccumulation was measured every 48 h. Koi carp bioturbation increased mean total suspended solids (TSS) in two trials from 0.001 mg/L to 44.4 mg/L and 19.2 mg/L to 762.4 mg/L. Mean aqueous Cd concentrations increased from1.4 {micro}g/L to 2.8 {micro}g/L, and from 1.6 {micro}g/L to 13.2 {micro}g/L. Cadmium binding capacity increased from 28.9 {micro}g/L to 169.8 {micro}g/L in with-fish treatments when compared to controls. However, Daphnia magna body burdens did not increase. Mean Cd residues of daphnids exposed with fish, 9.2 {micro}g/g, were not statistically different from without-fish exposures, 8.0 {micro}g/g. Body burdens slightly decreased in the first trial after the with-fish treatment, 9.4 {micro}g/g to 8.3 {micro}g/g. Fish size was partially correlated with TSS and aqueous Cd concentrations and TSS positively correlated with binding capacity. Because increased TSS in the with-fish treatment resulted in increased binding capacity, it is probable that cadmium bioavailability decreased. Although koi carp were capable of remobilizing Cd from sediment, Cd bioaccumulation into Daphnia magna was not significant.

  18. Olfactory toxicity in fishes.

    PubMed

    Tierney, Keith B; Baldwin, David H; Hara, Toshiaki J; Ross, Peter S; Scholz, Nathaniel L; Kennedy, Christopher J

    2010-01-21

    Olfaction conveys critical environmental information to fishes, enabling activities such as mating, locating food, discriminating kin, avoiding predators and homing. All of these behaviors can be impaired or lost as a result of exposure to toxic contaminants in surface waters. Historically, teleost olfaction studies have focused on behavioral responses to anthropogenic contaminants (e.g., avoidance). More recently, there has been a shift towards understanding the underlying mechanisms and functional significance of contaminant-mediated changes in fish olfaction. This includes a consideration of how contaminants affect the olfactory nervous system and, by extension, the downstream physiological and behavioral processes that together comprise a normal response to naturally occurring stimuli (e.g., reproductive priming or releasing pheromones). Numerous studies spanning several species have shown that ecologically relevant exposures to common pollutants such as metals and pesticides can interfere with fish olfaction and disrupt life history processes that determine individual survival and reproductive success. This represents one of the pathways by which toxic chemicals in aquatic habitats may increasingly contribute to the decline and at-risk status of many commercially and ecologically important fish stocks. Despite our emerging understanding of the threats that pollution poses for chemical communication in aquatic communities, many research challenges remain. These include: (1) the determination of specific mechanisms of toxicity in the fish olfactory sensory epithelium; (2) an understanding of the impacts of complex chemical mixtures; (3) the capacity to assess olfactory toxicity in fish in situ; (4) the impacts of toxins on olfactory-mediated behaviors that are still poorly understood for many fish species; and (5) the connections between sublethal effects on individual fish and the long-term viability of wild populations. This review summarizes and integrates

  19. Age & reproduction in three reef - dwelling serranid fishes of the northeastern Gulf of Mexico outer continental shelf: Pronotogrammus martinicensis, Hemanthias vivanus & Serranus phoebe (with preliminary observations on the Pomacentrid fish, Chromis enchrysurus)

    USGS Publications Warehouse

    Thurman, Paul E.; McBride, Richard S.; Sulak, Kenneth J.; Dennis, George D.

    2004-01-01

    Specimens of the four study species were collected during cruises to outer-continental shelf reefs of the northeastern Gulf of Mexico. Age was estimated for all serranid species using whole otoliths and C. enchrysurus ages were determined from transverse sections of sagittal otoliths. Ring structure observed on otoliths was validated as having an annual periodicity for P. martinicensis using marginal increment analysis. Ring structure on remaining species was assumed to correspond to age (years). Pronotogrammus martinicensis, H. vivanus, S. phoebe, and C. enchrysurus exhibited maximum ages of 9, 8, 5, and 11, respectively. Spatial variations in size-at-age were observed in P. martinicensis populations. Individuals inhabiting reefs in the Madison-Swanson Reserve area on the West Florida Shelf edge exhibited the fastest growth rates, while the slowest growing P. martinicensis were collected from the Alabama Alps Reef, the farthest west study reef. Pronotogrammus martinicensis and H. vivanus are both protogynous hermaphrodites. Evidence of active spawning was observed in the months from February through July for P. martinicensis, and March and May for H. vivanus. Serranus phoebe was observed to be a simultaneous hermaphroditic capable of spawning year-round. Batch fecundity estimates for P. martinicensis ranged from 149-394 oocytes per fish. Size selectivity was evident in our primary sampling method, hook and line using small tandem bait hooks. Smaller size-classes of all species examined were under-represented in our samples, hindering accurate growth modeling. Due to the protogynous nature of P. martinicensis and H. vivanus, hook and line sampling also tended to select for males. Future descriptions of the reproductive biology of both protogynous species would be more complete if less selective sampling methods could be successfully employed. The data presented here contribute to a better assessment of the fish community of the northeastern Gulf of Mexico. Little

  20. Monitoring Fish Contaminant Responses to Abatement Actions: Factors that Affect Recovery

    NASA Astrophysics Data System (ADS)

    Southworth, George R.; Peterson, Mark J.; Roy, W. Kelly; Mathews, Teresa J.

    2011-06-01

    Monitoring of contaminant accumulation in fish has been conducted in East Fork Poplar Creek (EFPC) in Oak Ridge, Tennessee since 1985. Bioaccumulation trends are examined over a twenty year period coinciding with major pollution abatement actions by a Department of Energy facility at the stream's headwaters. Although EFPC is enriched in many contaminants relative to other local streams, only polychlorinated biphenyls (PCBs) and mercury (Hg) were found to accumulate in the edible portions of fish to levels of human health concern. Mercury concentrations in redbreast sunfish were found to vary with season of collection, sex and size of individual fish. Over the course of the monitoring, waterborne Hg concentrations were reduced >80%; however, this did not translate into a comparable decrease in Hg bioaccumulation at most sites. Mercury bioaccumulation in fish did respond to decreased inputs in the industrialized headwater reach, but paradoxically increased in the lowermost reach of EFPC. As a result, the downstream pattern of Hg concentration in fish changed from one resembling dilution of a headwater point source in the 1980s to a uniform distribution in the 2000s. The reason for this remains unknown, but is hypothesized to involve changes in the chemical form and reactivity of waterborne Hg associated with the removal of residual chlorine and the addition of suspended particulates to the streamflow. PCB concentrations in fish varied greatly from year-to-year, but always exhibited a pronounced downstream decrease, and appeared to respond to management practices that limited episodic inputs from legacy sources within the facility.

  1. Monitoring Fish Contaminant Responses to Abatement Actions: Factors that Affect Recovery

    SciTech Connect

    Southworth, George R; Peterson, Mark J; Roy, W Kelly; Mathews, Teresa J

    2011-01-01

    Monitoring of contaminant accumulation in fish has been conducted in East Fork Poplar Creek (EFPC) in Oak Ridge, Tennessee since 1985. Bioaccumulation trends are examined over a twenty year period coinciding with major pollution abatement actions by a Department of Energy facility at the stream s headwaters. Although EFPC is enriched in many contaminants relative to other local streams, only polychlorinated biphenyls (PCBs) and mercury (Hg) were found to accumulate in the edible portions of fish to levels of human health concern. Mercury concentrations in redbreast sunfish were found to vary with season of collection, sex and size of individual fish. Over the course of the monitoring, waterborne Hg concentrations were reduced[80%; however, this did not translate into a comparable decrease in Hg bioaccumulation at most sites. Mercury bioaccumulation in fish did respond to decreased inputs in the industrialized headwater reach, but paradoxically increased in the lowermost reach of EFPC. As a result, the downstream pattern of Hg concentration in fish changed from one resembling dilution of a headwater point source in the 1980s to a uniform distribution in the 2000s. The reason for this remains unknown, but is hypothesized to involve changes in the chemical form and reactivity of waterborne Hg associated with the removal of residual chlorine and the addition of suspended particulates to the streamflow. PCB concentrations in fish varied greatly from year-to-year, but always exhibited a pronounced downstream decrease, and appeared to respond to management practices that limited episodic inputs from legacy sources within the facility.

  2. Does the Fukushima NPP disaster affect the caesium activity of North Atlantic Ocean fish?

    NASA Astrophysics Data System (ADS)

    Kanisch, G.; Aust, M.-O.

    2013-08-01

    Fillet samples of marine fish collected from the East/West Greenland currents (GC) and from the Baltic Sea (BS) have been investigated by gamma-ray spectrometry within the regular German monitoring programme. In samples of the second half of 2011, 134Cs traces have been detected that are suggested to originate from the Fukushima fallout that was deposited in March/April 2011 over the northern North Atlantic and accumulated by fish. The radionuclide 134Cs (half-life 2 yr) was indeed detected with quite small activities at about 0.0036 Bq kg-1 w.w. Existing box models describing the transport of Cs within seawater boxes of the northeast Atlantic allowed for estimation of 134Cs contributions from other sources, i.e. from the Chernobyl fallout and from discharges by the two major European nuclear reprocessing plants; both were negligible around Greenland, while for the Chernobyl fallout a small 134Cs background contribution to BS fish was estimated. Model results confirmed the level of 134C measured in BS fish and showed its maximum to have occurred in winter 2011/2012 followed by a continuous decrease. It was also determined that 134Cs activity, but not that of 134Cs, showed a significant negative correlation with sampling depth (150-400 m) of GC fish; this strengthens our Fukushima fallout assumption. As a result, the Fukushima fallout in these sea areas only marginally enhanced (GC: 4%; BS: 0.1%) pre-Fukushima levels of individual dose rates received by human fish consumers; the addition was around 0.001 μSv following the consumption of 10 kg of fish per year, which is not expected to cause concern according to present guidelines for radiation protection.

  3. The Consequences of Feminization in Breeding Groups of Wild Fish

    PubMed Central

    Harris, Catherine A.; Hamilton, Patrick B.; Runnalls, Tamsin J.; Vinciotti, Veronica; Henshaw, Alan; Hodgson, Dave; Coe, Tobias S.; Jobling, Susan; Tyler, Charles R.; Sumpter, John P.

    2011-01-01

    Background The feminization of nature by endocrine-disrupting chemicals (EDCs) is a key environmental issue affecting both terrestrial and aquatic wildlife. A crucial and as yet unanswered question is whether EDCs have adverse impacts on the sustainability of wildlife populations. There is widespread concern that intersex fish are reproductively compromised, with potential population-level consequences. However, to date, only in vitro sperm quality data are available in support of this hypothesis. Objective The aim of this study was to examine whether wild endocrine-disrupted fish can compete successfully in a realistic breeding scenario. Methods In two competitive breeding experiments using wild roach (Rutilus rutilus), we used DNA microsatellites to assign parentage and thus determine reproductive success of the adults. Results In both studies, the majority of intersex fish were able to breed, albeit with varying degrees of success. In the first study, where most intersex fish were only mildly feminized, body length was the only factor correlated with reproductive success. In the second study, which included a higher number of more severely intersex fish, reproductive performance was negatively correlated with severity of intersex. The intersex condition reduced reproductive performance by up to 76% for the most feminized individuals in this study, demonstrating a significant adverse effect of intersex on reproductive performance. Conclusion Feminization of male fish is likely to be an important determinant of reproductive performance in rivers where there is a high prevalence of moderately to severely feminized males. PMID:21362587

  4. The concentration of plasma metabolites varies throughout reproduction and affects offspring number in wild brown trout (Salmo trutta).

    PubMed

    Gauthey, Zoé; Freychet, Marine; Manicki, Aurélie; Herman, Alexandre; Lepais, Olivier; Panserat, Stéphane; Elosegi, Arturo; Tentelier, Cédric; Labonne, Jacques

    2015-06-01

    In wild populations, measuring energy invested in the reproduction and disentangling investment in gametes versus investment in reproductive behavior (such as intrasexual competition or intersexual preference) remain challenging. In this study, we investigated the energy expenditure in brown trout reproductive behavior by using two proxies: variation in weight and variation of plasma metabolites involved in energy production, over the course of reproductive season in a semi natural experimental river. We estimated overall reproductive success using genetic assignment at the end of the reproductive season. Results show that triglycerides and free fatty acid concentrations vary negatively during reproduction, while amino-acids and glucose concentrations remain stable. Decrease in triglyceride and free fatty acid concentrations during reproduction is not related to initial concentration levels or to weight variation. Both metabolite concentration variations and weight variations are correlated to the number of offspring produced, which could indicate that gametic and behavioral reproductive investments substantially contribute to reproductive success in wild brown trout. This study opens a path to further investigate variations in reproductive investment in wild populations.

  5. Genetic diversity affects the strength of population regulation in a marine fish.

    PubMed

    Johnson, D W; Freiwald, J; Bernardi, G

    2016-03-01

    Variation is an essential feature of biological populations, yet much of ecological theory treats individuals as though they are identical. This simplifying assumption is often justified by the perception that variation among individuals does not have significant effects on the dynamics of whole populations. However, this perception may be skewed by a historic focus on studying single populations. A true evaluation of the extent to which among-individual variation affects the dynamics of populations requires the study of multiple populations. In this study, we examined variation in the dynamics of populations of a live-bearing, marine fish (black surfperch; Embiotoca jacksoni). In collaboration with an organization of citizen scientists (Reef Check California), we were able to examine the dynamics of eight populations that were distributed throughout approximately 700 km of coastline, a distance that encompasses much of this species' range. We hypothesized that genetic variation within a local population would be related to the intensity of competition and to the strength of population regulation. To test this hypothesis, we examined whether genetic diversity (measured by the diversity of mitochondrial DNA haplotypes) was related to the strength of population regulation. Low-diversity populations experienced strong density dependence in population growth rates and population sizes were regulated much more tightly than they were in high-diversity populations. Mechanisms that contributed to this pattern include links between genetic diversity, habitat use, and spatial crowding. On average, low-diversity populations used less of the available habitat and exhibited greater spatial clustering (and more intense competition) for a given level of density (measured at the scale of the reef). Although the populations we studied also varied with respect to exogenous characteristics (habitat complexity, densities of predators, and interspecific competitors), none of these

  6. Mercury Contamination in an Indicator Fish Species from Andean Amazonian Rivers Affected by Petroleum Extraction.

    PubMed

    Webb, Jena; Coomes, Oliver T; Mainville, Nicolas; Mergler, Donna

    2015-09-01

    Elevated mercury (Hg) concentrations in fish from Amazonia have been associated with gold-mining, hydroelectric dams and deforestation but few studies consider the role of petroleum extraction. Hg levels were determined in fish samples collected in three river basins in Ecuador and Peru with contrasting petroleum exploitation and land-use characteristics. The non-migratory, piscivorous species, Hoplias malabaricus, was used as a bioindicator. The rate of Hg increase with body weight for this species was significantly higher on the Corrientes River, near the site of a recent oil spill, than on the other two rivers. In the absence of substantial deforestation and other anthropogenic sources in the Corrientes River basin, this finding suggests that oil contamination in Andean Amazonia may have a significant impact on Hg levels in fish.

  7. Increasing fish taxonomic and functional richness affects ecosystem properties of small headwater prairie streams

    DOE PAGES

    Martin, Erika C.; Gido, Keith B.; Bello, Nora; ...

    2016-04-06

    Stream fish can regulate their environment through direct and indirect pathways, and the relative influence of communities with different taxonomic and functional richness on ecosystem properties likely depends on habitat structure. Given this complexity, it is not surprising that observational studies of how stream fish communities influence ecosystems have shown mixed results. In this study, we evaluated the effect of an observed gradient of taxonomic (zero, one, two or three species) and functional (zero, one or two groups) richness of fishes on several key ecosystem properties in experimental stream mesocosms. Our study simulated small (less than two metres wide) headwatermore » prairie streams with a succession of three pool-riffle structures (upstream, middle and downstream) per mesocosm. Additionally, ecosystem responses included chlorophyll a from floating algal mats and benthic algae, benthic organic matter, macroinvertebrates (all as mass per unit area), algal filament length and stream metabolism (photosynthesis and respiration rate). Ecosystem responses were analysed individually using general linear mixed models. Significant treatment (taxonomic and functional richness) by habitat (pools and riffles) interactions were found for all but one ecosystem response variable. After accounting for location (upstream, middle and downstream) effects, the presence of one or two grazers resulted in shorter mean algal filament lengths in pools compared to no-fish controls. These observations suggest grazers can maintain short algal filaments in pools, which may inhibit long filaments from reaching the surface. Accordingly, floating algal mats decreased in mid- and downstream locations in grazer treatment relative to no-fish controls. At the scale of the entire reach, gross primary productivity and respiration were greater in treatments with two grazer species compared to mixed grazer/insectivore or control treatments. Lastly, the distribution of stream resources

  8. Increasing fish taxonomic and functional richness affects ecosystem properties of small headwater prairie streams

    SciTech Connect

    Martin, Erika C.; Gido, Keith B.; Bello, Nora; Dodds, Walter K.; Veach, Allison

    2016-04-06

    Stream fish can regulate their environment through direct and indirect pathways, and the relative influence of communities with different taxonomic and functional richness on ecosystem properties likely depends on habitat structure. Given this complexity, it is not surprising that observational studies of how stream fish communities influence ecosystems have shown mixed results. In this study, we evaluated the effect of an observed gradient of taxonomic (zero, one, two or three species) and functional (zero, one or two groups) richness of fishes on several key ecosystem properties in experimental stream mesocosms. Our study simulated small (less than two metres wide) headwater prairie streams with a succession of three pool-riffle structures (upstream, middle and downstream) per mesocosm. Additionally, ecosystem responses included chlorophyll a from floating algal mats and benthic algae, benthic organic matter, macroinvertebrates (all as mass per unit area), algal filament length and stream metabolism (photosynthesis and respiration rate). Ecosystem responses were analysed individually using general linear mixed models. Significant treatment (taxonomic and functional richness) by habitat (pools and riffles) interactions were found for all but one ecosystem response variable. After accounting for location (upstream, middle and downstream) effects, the presence of one or two grazers resulted in shorter mean algal filament lengths in pools compared to no-fish controls. These observations suggest grazers can maintain short algal filaments in pools, which may inhibit long filaments from reaching the surface. Accordingly, floating algal mats decreased in mid- and downstream locations in grazer treatment relative to no-fish controls. At the scale of the entire reach, gross primary productivity and respiration were greater in treatments with two grazer species compared to mixed grazer/insectivore or control treatments. Lastly, the distribution of stream resources across

  9. Appropriate timing of uterine cavity length measurement positively affects assisted reproduction cycle outcome.

    PubMed

    Madani, Tahereh; Ashrafi, Mahnaz; Abadi, Akram Bahman; Kiani, Kiandokht

    2009-11-01

    An appropriate and easy embryo transfer has a direct impact on pregnancy rates. Proper evaluation of the uterocervical axis and uterine depth are necessary for suitable embryo transfer. The aim of this study was to assess the appropriate time for cervical axis evaluation and uterine measurement. A total of 124 patients undergoing IVF treatment were included in the study. They were divided equally into two groups. In group I (62 women), uterine cavity depth was measured and the uterocervical axis was determined on day 2 or 3 of the menstrual cycle, and in group II (62 women) at the time of oocyte retrieval. There was a statistically significant difference in clinical pregnancy rates between the two groups (P = 0.006). Thirty-four women became pregnant in group I (64.2%) versus 19 women in group II (35.8%). In conclusion, uterine cavity measurement is necessary for suitable embryo transfer. It seems that the time of measurement significantly affects clinical pregnancy rate in IVF cycles. The best time for uterine measurement is on day 2 or 3 of menstruation.

  10. Individual heterogeneity and offspring sex affect the growth-reproduction trade-off in a mammal with indeterminate growth.

    PubMed

    Gélin, Uriel; Wilson, Michelle E; Cripps, Jemma; Coulson, Graeme; Festa-Bianchet, Marco

    2016-04-01

    Reproduction can lead to a trade-off with growth, particularly when individuals reproduce before completing body growth. Kangaroos have indeterminate growth and may always face this trade-off. We combined an experimental manipulation of reproductive effort and multi-year monitoring of a large sample size of marked individuals in two populations of eastern grey kangaroos to test the predictions (1) that reproduction decreases skeletal growth and mass gain and (2) that mass loss leads to reproductive failure. We also tested if sex-allocation strategies influenced these trade-offs. Experimental reproductive suppression revealed negative effects of reproduction on mass gain and leg growth from 1 year to the next. Unmanipulated females, however, showed a positive correlation between number of days lactating and leg growth over periods of 2 years and longer, suggesting that over the long term, reproductive costs were masked by individual heterogeneity in resource acquisition. Mass gain was necessary for reproductive success the subsequent year. Although mothers of daughters generally lost more mass than females nursing sons, mothers in poor condition experienced greater mass gain and arm growth if they had daughters than if they had sons. The strong links between individual mass changes and reproduction suggest that reproductive tactics are strongly resource-dependent.

  11. Temperature and resource availability may interactively affect over-wintering success of juvenile fish in a changing climate.

    PubMed

    Brodersen, Jakob; Rodriguez-Gil, José Luis; Jönsson, Mikael; Hansson, Lars-Anders; Brönmark, Christer; Nilsson, P Anders; Nicolle, Alice; Berglund, Olof

    2011-01-01

    The predicted global warming may affect freshwater systems at several organizational levels, from organism to ecosystem. Specifically, in temperate regions, the projected increase of winter temperatures may have important effects on the over-winter biology of a range of organisms and especially for fish and other ectothermic animals. However, temperature effects on organisms may be directed strongly by resource availability. Here, we investigated whether over-winter loss of biomass and lipid content of juvenile roach (Rutilus rutilus) was affected by the physiologically relatively small (2-5 °C) changes of winter temperatures predicted by the Intergovernmental Panel on Climate Change (IPCC), under both natural and experimental conditions. This was investigated in combination with the effects of food availability. Finally, we explored the potential for a correlation between lake temperature and resource levels for planktivorous fish, i.e., zooplankton biomass, during five consecutive winters in a south Swedish lake. We show that small increases in temperature (+2 °C) affected fish biomass loss in both presence and absence of food, but negatively and positively respectively. Temperature alone explained only a minor part of the variation when food availability was not taken into account. In contrast to other studies, lipid analyses of experimental fish suggest that critical somatic condition rather than critical lipid content determined starvation induced mortality. Our results illustrate the importance of considering not only changes in temperature when predicting organism response to climate change but also food-web interactions, such as resource availability and predation. However, as exemplified by our finding that zooplankton over-winter biomass in the lake was not related to over-winter temperature, this may not be a straightforward task.

  12. Temperature and Resource Availability May Interactively Affect Over-Wintering Success of Juvenile Fish in a Changing Climate

    PubMed Central

    Brodersen, Jakob; Rodriguez-Gil, José Luis; Jönsson, Mikael; Hansson, Lars-Anders; Brönmark, Christer; Nilsson, P. Anders; Nicolle, Alice; Berglund, Olof

    2011-01-01

    The predicted global warming may affect freshwater systems at several organizational levels, from organism to ecosystem. Specifically, in temperate regions, the projected increase of winter temperatures may have important effects on the over-winter biology of a range of organisms and especially for fish and other ectothermic animals. However, temperature effects on organisms may be directed strongly by resource availability. Here, we investigated whether over-winter loss of biomass and lipid content of juvenile roach (Rutilus rutilus) was affected by the physiologically relatively small (2-5°C) changes of winter temperatures predicted by the Intergovernmental Panel on Climate Change (IPCC), under both natural and experimental conditions. This was investigated in combination with the effects of food availability. Finally, we explored the potential for a correlation between lake temperature and resource levels for planktivorous fish, i.e., zooplankton biomass, during five consecutive winters in a south Swedish lake. We show that small increases in temperature (+2°C) affected fish biomass loss in both presence and absence of food, but negatively and positively respectively. Temperature alone explained only a minor part of the variation when food availability was not taken into account. In contrast to other studies, lipid analyses of experimental fish suggest that critical somatic condition rather than critical lipid content determined starvation induced mortality. Our results illustrate the importance of considering not only changes in temperature when predicting organism response to climate change but also food-web interactions, such as resource availability and predation. However, as exemplified by our finding that zooplankton over-winter biomass in the lake was not related to over-winter temperature, this may not be a straightforward task. PMID:21998627

  13. Which molecular features affect the intrinsic hepatic clearance rate of ionizable organic chemicals in fish?

    EPA Science Inventory

    Greater knowledge of biotransformation rates for ionizable organic compounds (IOCs) in fish is required to properly assess the bioaccumulation potential of many environmentally relevant contaminants. In this study we measured in vitro hepatic clearance rates for 50 IOCs using a p...

  14. Hierarchy in factors affecting fish biodiversity in floodplain lakes of the Mississippi Alluvial Valley

    USGS Publications Warehouse

    Dembkowski, D.J.; Miranda, L.E.

    2012-01-01

    River-floodplain ecosystems offer some of the most diverse and dynamic environments in the world. Accordingly, floodplain habitats harbor diverse fish assemblages. Fish biodiversity in floodplain lakes may be influenced by multiple variables operating on disparate scales, and these variables may exhibit a hierarchical organization depending on whether one variable governs another. In this study, we examined the interaction between primary variables descriptive of floodplain lake large-scale features, suites of secondary variables descriptive of water quality and primary productivity, and a set of tertiary variables descriptive of fish biodiversity across a range of floodplain lakes in the Mississippi Alluvial Valley of Mississippi and Arkansas (USA). Lakes varied considerably in their representation of primary, secondary, and tertiary variables. Multivariate direct gradient analyses indicated that lake maximum depth and the percentage of agricultural land surrounding a lake were the most important factors controlling variation in suites of secondary and tertiary variables, followed to a lesser extent by lake surface area. Fish biodiversity was generally greatest in large, deep lakes with lower proportions of watershed agricultural land. Our results may help foster a holistic approach to floodplain lake management and suggest the framework for a feedback model wherein primary variables can be manipulated for conservation and restoration purposes and secondary and tertiary variables can be used to monitor the success of such efforts. ?? 2011 Springer Science+Business Media B.V.

  15. Factors affecting fish biodiversity in floodplain lakes of the Mississippi Alluvial Valley

    USGS Publications Warehouse

    Miranda, Leandro E.; Dembkowski, Daniel J.

    2012-01-01

    River-floodplain ecosystems offer some of the most diverse and dynamic environments in the world. Accordingly, floodplain habitats harbor diverse fish assemblages. Fish biodiversity in floodplain lakes may be influenced by multiple variables operating on disparate scales, and these variables may exhibit a hierarchical organization depending on whether one variable governs another. In this study, we examined the interaction between primary variables descriptive of floodplain lake large-scale features, suites of secondary variables descriptive of water quality and primary productivity, and a set of tertiary variables descriptive of fish biodiversity across a range of floodplain lakes in the Mississippi Alluvial Valley of Mississippi and Arkansas (USA). Lakes varied considerably in their representation of primary, secondary, and tertiary variables. Multivariate direct gradient analyses indicated that lake maximum depth and the percentage of agricultural land surrounding a lake were the most important factors controlling variation in suites of secondary and tertiary variables, followed to a lesser extent by lake surface area. Fish biodiversity was generally greatest in large, deep lakes with lower proportions of watershed agricultural land. Our results may help foster a holistic approach to floodplain lake management and suggest the framework for a feedback model wherein primary variables can be manipulated for conservation and restoration purposes and secondary and tertiary variables can be used to monitor the success of such efforts.

  16. Waves affect predator-prey interactions between fish and benthic invertebrates.

    PubMed

    Gabel, Friederike; Stoll, Stefan; Fischer, Philipp; Pusch, Martin T; Garcia, Xavier-François

    2011-01-01

    Little is known about the effects of waves on predator-prey interactions in the littoral zones of freshwaters. We conducted a set of mesocosm experiments to study the differential effects of ship- and wind-induced waves on the foraging success of littoral fish on benthic invertebrates. Experiments were conducted in a wave tank with amphipods (Gammarus roeseli) as prey, and age-0 bream (Abramis brama, B0), age-0 and age-1 dace (Leuciscus leuciscus, D0 and D1) as predators. The number of gammarids suspended in the water column was higher in the wave treatments compared to a no-wave control treatment, especially during pulse waves mimicking ship-induced waves in comparison to continuous waves mimicking wind-induced waves. The resulting higher prey accessibility in the water column was differently exploited by the three types of predatory fish. D0 and D1 showed significantly higher foraging success in the pulse wave treatment than in the continuous and control treatments. The foraging success of D0 appears to be achieved more easily, since significantly higher swimming activity and more foraging attempts were recorded only for D1 under the wave treatments. In contrast, B0 consumed significantly fewer gammarids in both wave treatments than in the control. Hence, waves influenced predator-prey interactions differently depending on wave type and fish type. It is expected that regular exposure to ship-induced waves can alter littoral invertebrate and fish assemblages by increasing the predation risk for benthic invertebrates that are suspended in the water column, and by shifting fish community compositions towards species that benefit from waves.

  17. Factors affecting effective communication about sexual and reproductive health issues between parents and adolescents in zandspruit informal settlement, Johannesburg, South Africa

    PubMed Central

    Motsomi, Kegaugetswe; Makanjee, Chandra; Basera, Tariro; Nyasulu, Peter

    2016-01-01

    Introduction Communication between parents and adolescents regarding sexuality is an important reproductive health topic. Due to complexities associated with adolescent's physiological development, sexuality should be dealt with holistically. This study aimed to investigate factors affecting effective communication between parents and adolescents concerning sexual and reproductive health issues. Methods An exploratory qualitative study using the focus group discussions method was done to explore amongst other things; social, cultural and religious barriers to communication. Thematic content analysis was done. Results Factors identified included: embarrassment when discussing sexual topics; adolescent misperceptions that guardians want to engage in sexual activities with them; strong belief amongst guardians that reproductive health discussions with adolescents encourages sexual experimentation; belief that adolescents were too young to understand; non-conducive environment for open discussions of sexual and reproductive health matters; cultural and religious beliefs. Conclusion In view of these findings, there are still barriers in terms of parent-adolescent engagement on issues related to risks associated with sexual behaviours and erroneous reproductive health choices among adolescents. Therefore, there is a need to encourage engagement by creating neutral platforms facilitated by community healthcare providers and/ or social workers. This will help create awareness and bridge the communication and interaction gap by emphasising the importance of effective engagement among adolescents and their parents on matters related to risks associated with sexual behaviours and erroneous reproductive health choices. Post implantation intervention studies are needed to inform on the outcomes of the intervention. PMID:28292083

  18. Phytoestrogens β -sitosterol and genistein have limited effects on reproductive endpoints in a female fish, Betta splendens.

    PubMed

    Brown, A C; Stevenson, L M; Leonard, H M; Nieves-Puigdoller, K; Clotfelter, E D

    2014-01-01

    Phytoestrogens are produced by plants and may cause endocrine disruption in vertebrates. The present study hypothesizes that phytoestrogen exposure of female Siamese fighting fish (Betta splendens) may disrupt endogenous steroid levels, change agonistic behavior expression, and potentially also disrupt oocyte development. However, only the pharmacologic dose of β-sitosterol had a significant effect on opercular flaring behavior, while we did not find significant effects of β-sitosterol or genistein on steroids or gonads. These findings are in direct contrast with previous studies on the effects of phytoestrogens in female fish. Results of the current study support previous work showing that the effects of phytoestrogen exposure may be less acute in mature female B. splendens than in other fish.

  19. Phytoestrogens β-Sitosterol and Genistein Have Limited Effects on Reproductive Endpoints in a Female Fish, Betta splendens

    PubMed Central

    Brown, A. C.; Stevenson, L. M.; Leonard, H. M.; Nieves-Puigdoller, K.; Clotfelter, E. D.

    2014-01-01

    Phytoestrogens are produced by plants and may cause endocrine disruption in vertebrates. The present study hypothesizes that phytoestrogen exposure of female Siamese fighting fish (Betta splendens) may disrupt endogenous steroid levels, change agonistic behavior expression, and potentially also disrupt oocyte development. However, only the pharmacologic dose of β-sitosterol had a significant effect on opercular flaring behavior, while we did not find significant effects of β-sitosterol or genistein on steroids or gonads. These findings are in direct contrast with previous studies on the effects of phytoestrogens in female fish. Results of the current study support previous work showing that the effects of phytoestrogen exposure may be less acute in mature female B. splendens than in other fish. PMID:24707495

  20. Female access and diet affect insemination success, senescence, and the cost of reproduction in male Mexican fruit flies Anastrepha ludens.

    PubMed

    Harwood, James F; Chen, Kehui; Liedo, Pablo; Müller, Hans-Georg; Wang, Jane-Ling; Morice, Amy E; Carey, James R

    2015-03-01

    Hypotheses exploring the influence of dietary conditions on the life history trade-off between survival and reproductive success are extensively tested in female insects, but are rarely explored in males. Here, the impact of dietary quality and female access on age-specific reproduction and survival of male Mexican fruit flies, Anastrepha ludens Loew (Diptera: Tephritidae), are examined. There is a clear cost of female access for males with access to dietary protein, measurable as a decrease in life expectancy, which is further influenced by the age when females are introduced. A protein deficient diet reduces the lifespan benefit of virginity and masks the detrimental effect of female access on male life expectancy. Dietary protein is not necessary for reproductive success, but access to protein at eclosion improves the lifetime reproductive success of males compared to when it is delayed. Overall, reproductive success diminishes as the male flies age, regardless of the dietary conditions, providing evidence for reproductive senescence in males. Delaying the males' access to a protein source fails to influence the negative effect of age on reproductive ability. Because age specific reproductive rates decline with age, regardless of diet, male fitness does not benefit from lifespan extension. Therefore, males can be expected to allocate available resources towards reproductive effort in favour of extended lifespan, regardless of mate and protein availability.

  1. Female access and diet affect insemination success, senescence, and the cost of reproduction in male Mexican fruit flies Anastrepha ludens

    PubMed Central

    HARWOOD, JAMES F.; CHEN, KEHUI; LIEDO, PABLO; MÜLLER, HANS-GEORG; WANG, JANE-LING; MORICE, AMY E.; CAREY, JAMES R.

    2014-01-01

    Hypotheses exploring the influence of dietary conditions on the life history trade-off between survival and reproductive success are extensively tested in female insects, but are rarely explored in males. Here, the impact of dietary quality and female access on age-specific reproduction and survival of male Mexican fruit flies, Anastrepha ludens Loew (Diptera: Tephritidae), are examined. There is a clear cost of female access for males with access to dietary protein, measurable as a decrease in life expectancy, which is further influenced by the age when females are introduced. A protein deficient diet reduces the lifespan benefit of virginity and masks the detrimental effect of female access on male life expectancy. Dietary protein is not necessary for reproductive success, but access to protein at eclosion improves the lifetime reproductive success of males compared to when it is delayed. Overall, reproductive success diminishes as the male flies age, regardless of the dietary conditions, providing evidence for reproductive senescence in males. Delaying the males’ access to a protein source fails to influence the negative effect of age on reproductive ability. Because age specific reproductive rates decline with age, regardless of diet, male fitness does not benefit from lifespan extension. Therefore, males can be expected to allocate available resources towards reproductive effort in favour of extended lifespan, regardless of mate and protein availability. PMID:25709143

  2. THE ESTROGENIC AND ANTIANDROGENIC PESTICIDE METHOXYCHLOR ALTERS THE REPRODUCTIVE TRACT AND BEHAVIOR WITHOUT AFFECTING PITUITARY SIZE OR LH AND PROLACTIN SECRETION IN MALE RATS

    EPA Science Inventory

    The estrogenic and antiandrogenic pesticide methoxychlor alters the reproductive tract and behavior without affecting pituitary size or LH and prolactin secretion in male rats.

    Gray LE Jr, Ostby J, Cooper RL, Kelce WR.

    Endocrinology Branch, United States Environment...

  3. Plasma inflammatory and vascular homeostasis biomarkers increase during human pregnancy but are not affected by oily fish intake.

    PubMed

    García-Rodríguez, Cruz E; Olza, Josune; Aguilera, Concepción M; Mesa, María D; Miles, Elizabeth A; Noakes, Paul S; Vlachava, Maria; Kremmyda, Lefkothea-Stella; Diaper, Norma D; Godfrey, Keith M; Calder, Philip C; Gil, Angel

    2012-07-01

    The Salmon in Pregnancy Study investigated whether the increased consumption of (n-3) long-chain PUFA (LC-PUFA) from farmed Atlantic salmon affects immune function during pregnancy and atopic disease in neonates compared with a habitual diet low in oily fish. In this context, because the ingestion of (n-3) LC-PUFA may lower the concentrations of inflammatory biomarkers, we investigated whether the consumption of oily fish affects the levels of inflammatory cytokines and vascular adhesion factors during pregnancy. Pregnant women (n = 123) were randomly assigned to continue their habitual diet (control group, n = 61), which was low in oily fish, or to consume two 150-g salmon portions/wk (salmon group, n = 62; providing 3.45 g EPA plus DHA) from 20 wk of gestation until delivery. Plasma inflammatory cytokines and vascular adhesion factors were measured in maternal plasma samples. Inflammatory biomarkers, including IL-8, hepatocyte growth factor, and monocyte chemotactic protein, increased over the course of pregnancy (P < 0.001), whereas plasma matrix metalloproteinase 9, IL-6, TNFα, and nerve growth factor concentrations were not affected. Vascular homeostasis biomarkers soluble E-selectin, soluble vascular adhesion molecule-1, soluble intercellular adhesion molecule (sICAM)-1, and total plasminogen activator inhibitor-1 increased as pregnancy progressed (P < 0.001). The plasma sICAM-1 concentration was greater in the control group than in the salmon group at wk 20 (baseline) and 38 (P = 0.007) but there was no group x time interaction, and when baseline concentration was used as a covariate, the groups did not differ (P = 0.69). The remaining biomarkers analyzed were similar in both groups. Therefore, although some inflammatory and vascular homeostasis biomarkers change during pregnancy, they are not affected by the increased intake of farmed salmon.

  4. 5S rRNA and accompanying proteins in gonads: powerful markers to identify sex and reproductive endocrine disruption in fish.

    PubMed

    Diaz de Cerio, Oihane; Rojo-Bartolomé, Iratxe; Bizarro, Cristina; Ortiz-Zarragoitia, Maren; Cancio, Ibon

    2012-07-17

    In anuran ovaries, 5S rDNA is regulated transcriptionally by transcription factor IIIA (TFIIIA), which upon transcription, binds 5S rRNA, forming 7S RNP. 5S rRNA can be stockpiled also in the form of 42S RNP bound to 42sp43. The aim of the present study was to assess the differential transcriptional regulation of 5S rRNA and associated proteins in thicklip gray mullet (Chelon labrosus) gonads. Up to 75% of the total RNA from mullet ovaries was 5S rRNA. qPCR quantification of 5S rRNA expression, in gonads of histologically sexed individuals from different geographical areas, successfully sexed animals. All males had expression levels that were orders of magnitude below expression levels in females, throughout an annual reproductive cycle, with the exception of two individuals: one in November and one in December. Moreover, intersex mullets from a polluted harbor had expression levels between both sexes. TFIIIA and 42sp43 were also very active transcriptionally in gonads of female and intersex mullets, in comparison to males. Nucleocytoplasmatic transport is important in this context and we also analyzed transcriptional levels of importins-α1, -α2, and -β2 and different exportins. Importin-αs behaved similarly to 5S rRNA. Thus, 5S rRNA and associated proteins constitute very powerful molecular markers of sex and effects of xenosterogens in fish gonads, with potential technological applications in the analysis of fish stock dynamics and reproduction as well as in environmental health assessment.

  5. Developmental Exposure to Ethinylestradiol Affects Reproductive Physiology, the GnRH Neuroendocrine Network and Behaviors in Female Mouse

    PubMed Central

    Derouiche, Lyes; Keller, Matthieu; Martini, Mariangela; Duittoz, Anne H.; Pillon, Delphine

    2015-01-01

    During development, environmental estrogens are able to induce an estrogen mimetic action that may interfere with endocrine and neuroendocrine systems. The present study investigated the effects on the reproductive function in female mice following developmental exposure to pharmaceutical ethinylestradiol (EE2), the most widespread and potent synthetic steroid present in aquatic environments. EE2 was administrated in drinking water at environmentally relevant (ENVIR) or pharmacological (PHARMACO) doses [0.1 and 1 μg/kg (body weight)/day respectively], from embryonic day 10 until postnatal day 40. Our results show that both groups of EE2-exposed females had advanced vaginal opening and shorter estrus cycles, but a normal fertility rate compared to CONTROL females. The hypothalamic population of GnRH neurons was affected by EE2 exposure with a significant increase in the number of perikarya in the preoptic area of the PHARMACO group and a modification in their distribution in the ENVIR group, both associated with a marked decrease in GnRH fibers immunoreactivity in the median eminence. In EE2-exposed females, behavioral tests highlighted a disturbed maternal behavior, a higher lordosis response, a lack of discrimination between gonad-intact and castrated males in sexually experienced females, and an increased anxiety-related behavior. Altogether, these results put emphasis on the high sensitivity of sexually dimorphic behaviors and neuroendocrine circuits to disruptive effects of EDCs. PMID:26696819

  6. Factors affecting reproductive performance of white-tailed deer subjected to fixed-time artificial insemination or natural mating.

    PubMed

    Mellado, Miguel; Orta, Claudia G; Lozano, Eloy A; García, Jose E; Veliz, Francisco G; de Santiago, Angeles

    2013-01-01

    The objectives of this study were to examine the effects of several factors affecting fawning rate, litter size, litter weight and neonatal fawn mortality in white-tailed deer inseminated either transcervically or by means of laparoscopy. Oestrus synchronisation with a controlled internal drug release (CIDR)-based protocol and fixed-time artificial insemination (FTAI) was conducted in 130 white-tailed deer (Odocoileus virginianus texanus) during three reproductive seasons (2007-2009; 271 services) in a game-hunting ranch in a hot-arid environment (26°4' N, 101°25' W). Ninety additional non-treated does were exposed to bucks for natural mating. Fawning rate did not differ between AI methods (40.0 vs 45.0% for transcervical and laparoscopic AI, respectively). Overall fawning rate (proportion of all does fawning after FTAI and a subsequent period of buck exposure) did not differ between transcervical (89.5%), laparoscopic (80.3%) or natural (88.9%) insemination. Litter size per fawning doe was higher (P<0.05) in naturally-served does (1.65±0.48) than in transcervically-inseminated does (1.40±0.51) or in laparoscopically-inseminated does (1.48±0.50). The main conclusion was that no enhancement of fawning rate or litter size occurred as a result of intrauterine deposition of semen by laparoscopy compared with the transcervical insemination technique.

  7. Grape variety affects larval performance and also female reproductive performance of the European grapevine moth Lobesia botrana (Lepidoptera: Tortricidae).

    PubMed

    Moreau, J; Benrey, B; Thiéry, D

    2006-04-01

    For insect herbivores, the quality of the larval host plant is a key determinant of fitness. Therefore, insect populations are supposed to be positively correlated with the nutritional quality of their host plant. This study aimed to determine if and how different varieties of grapes (including the wild grape Lambrusque) affect both larval and adult performance of the polyphagous European grapevine moth Lobesia botrana (Denis & Schiffermüller). Significant differences were found in larval development time, but not in pupal mass, adult emergence rate, or sex ratio. Although the fecundity of females is not different among varieties, females fed on some varieties produced eggs of different sizes which are correlated to their fertility. Thus, females adapt resource allocation to eggs depending on their diet as larvae. Using a fitness index, the average reproductive output was found to be highest for females reared on cv. Chardonnay. Females reared on wild grape produced a fitness index identical to the cultivated grapes. However, Lambrusque and Gewurztraminer separate themselves from the cultivated varieties according to our discriminant analyses. It is emphasized, through this study, that cultivars fed on by larvae should be considered in the population dynamics of L. botrana and that egg number is insufficient to determine host plant quality.

  8. CO2 and fertility affect growth and reproduction but not susceptibility to aphids in field grown Solanum ptycanthum

    SciTech Connect

    Long, T.M.

    1995-09-01

    In general, C3 annual plants respond positively in terms of growth, reproduction and biomass accrued when grown under elevated levels of atmospheric carbon dioxide. However, most studies documenting this response have been conducted in growth chambers where plants can be reared under conditions free form environmental stressors such as nutrient and water constraints, UV exposure and damage from pests. During the 1993 fieldseason, I grew 200 individuals of Solanum ptycanthum in an array of 10 outdoor, open-topped CO2 enclosures (5 @ 700 ppm CO2) at the University of Michigan Biological Station in Pellston, MI. Half of the plants were grown in a 50;50 mix of native C-horizon soil and topsoil (low fertility); the other half were grown in 100% topsoil (high-fertility). Plants were censused throughout the growing season for flower and fruit production, growth rate and degree of infestation of aphids. Fertility and CO2 both significantly affected production of flowers and fruits, but only fertility was significantly related to vegetative growth. Aphid infestation varied significantly among enclosures, but was not related to CO2 or fertility.

  9. Active immunization against leptin fails to affect reproduction and exerts only marginal effects on glucose metabolism in young female goats.

    PubMed

    Sauerwein, H; Heintges, U; Bruhns, S C; Hennies, M; Gertler, A

    2006-08-01

    Approximately 150 days before expected breeding time, 12 female goats (3 months of age) were actively immunized against ovine leptin. Booster injections were given throughout the following year. Control animals (n = 6) were sham-immunized. After the first observed oestrus, a buck was introduced and goats were mated. Blood samples were collected twice weekly and frequent blood sampling series were performed on days -15, 76, 153 and 286 relative to the first immunization. Nine of the immunized goats developed titres within 3 months and had elevated serum concentrations of leptin compared with controls (p < 0.0001). Hematological parameters and blood chemistry were not affected by the immunization. No differences were detectable in all reproductive parameters recorded. Serum insulin was higher in immunized goats during the frequent blood sampling series of day 287 after the first immunization. Glucose metabolism was investigated during pregnancy using hyperglycaemic and euglycaemic/hyperinsulinaemic clamps. None of the parameters derived from the clamp studies was different (p > 0.05) between the two groups. During the hyperglycaemic clamp there was a trend (p < 0.15) towards increased insulin concentrations in immunized animals whereas glucose infusion rates were not different between the groups. This indicates decreased insulin sensitivity in immunized goats. Our study describes the ontogenesis of serum concentrations of leptin during growth, puberty and first pregnancy and parturition for the caprine species. The effects of the immunization were not detectable or only marginal and the approach aimed at therefore not effective to investigate leptin action in detail.

  10. Development on drought-stressed host plants affects life history, flight morphology and reproductive output relative to landscape structure.

    PubMed

    Gibbs, Melanie; Van Dyck, Hans; Breuker, Casper J

    2012-01-01

    With global climate change, rainfall is becoming more variable. Predicting the responses of species to changing rainfall levels is difficult because, for example in herbivorous species, these effects may be mediated indirectly through changes in host plant quality. Furthermore, species responses may result from a simultaneous interaction between rainfall levels and other environmental variables such as anthropogenic land use or habitat quality. In this eco-evolutionary study, we examined how male and female Pararge aegeria (L.) from woodland and agricultural landscape populations were affected by the development on drought-stressed host plants. Compared with individuals from woodland landscapes, when reared on drought-stressed plants agricultural individuals had longer development times, reduced survival rates and lower adult body masses. Across both landscape types, growth on drought-stressed plants resulted in males and females with low forewing aspect ratios and in females with lower wing loading and reduced fecundity. Development on drought-stressed plants also had a landscape-specific effect on reproductive output; agricultural females laid eggs that had a significantly lower hatching success. Overall, our results highlight several potential mechanisms by which low water availability, via changes in host plant quality, may differentially influence P. aegeria populations relative to landscape structure.

  11. Global warming may disproportionately affect larger adults in a predatory coral reef fish.

    PubMed

    Messmer, Vanessa; Pratchett, Morgan S; Hoey, Andrew S; Tobin, Andrew J; Coker, Darren J; Cooke, Steven J; Clark, Timothy D

    2016-11-03

    Global warming is expected to reduce body sizes of ectothermic animals. Although the underlying mechanisms of size reductions remain poorly understood, effects appear stronger at latitudinal extremes (poles and tropics) and in aquatic rather than terrestrial systems. To shed light on this phenomenon, we examined the size dependence of critical thermal maxima (CTmax) and aerobic metabolism in a commercially important tropical reef fish, the leopard coral grouper (Plectropomus leopardus) following acclimation to current-day (28.5 °C) vs. projected end-of-century (33 °C) summer temperatures for the northern Great Barrier Reef (GBR). CTmax declined from 38.3 to 37.5 °C with increasing body mass in adult fish (0.45-2.82 kg), indicating that larger individuals are more thermally sensitive than smaller conspecifics. This may be explained by a restricted capacity for large fish to increase mass-specific maximum metabolic rate (MMR) at 33 °C compared with 28.5 °C. Indeed, temperature influenced the relationship between metabolism and body mass (0.02-2.38 kg), whereby the scaling exponent for MMR increased from 0.74 ± 0.02 at 28.5 °C to 0.79 ± 0.01 at 33 °C, and the corresponding exponents for standard metabolic rate (SMR) were 0.75 ± 0.04 and 0.80 ± 0.03. The increase in metabolic scaling exponents at higher temperatures suggests that energy budgets may be disproportionately impacted in larger fish and contribute to reduced maximum adult size. Such climate-induced reductions in body size would have important ramifications for fisheries productivity, but are also likely to have knock-on effects for trophodynamics and functioning of ecosystems.

  12. Reproductive biology of Ilisha elongata (Teleostei: Pristigasteridae) in Ariake Sound, Japan: Implications for estuarine fish conservation in Asia

    NASA Astrophysics Data System (ADS)

    Zhang, Jie; Takita, Toru; Zhang, Chunguang

    2009-01-01

    Elongate ilisha ( Ilisha enlongata) is a commercially important species that contributes to clupeoid fisheries in Asian countries. In the present study, the reproductive biology of I. elongata in Ariake Sound, Japan is determined for the first time. Six maturity stages were described using ovarian and testicular histology throughout the annual cycle. The spawning season in Ariake Sound lasts from May to July, with peak spawning activity in May and June. Age at first maturity was estimated to be 2 years, with a few exceptions of 1 year in well-developed males. Ovaries that contained both tertiary yolk oocytes and postovulatory follicles occurred from late May to late July, indicating that I. elongata is a multiple spawner. The size-frequency distribution of oocytes provided evidence for its multiple spawning and accuracy of the fecundity estimates. The batch fecundity of this species was estimated at between 22,200 and 270,900 eggs per individual, increasing with age between two and six years. The present findings on the reproductive strategy of I. elongata in Ariake Sound are generally consistent with those in temperate or subtropical populations, but quite different from those of tropical population where first maturation occurs around 200 days and life spans are shorter, with a maximum age less than 3 years. The conservation implications of this reproductive strategy in a harsh, variable environment in Asian countries are also discussed.

  13. Spotlight on fish: light pollution affects circadian rhythms of European perch but does not cause stress.

    PubMed

    Brüning, Anika; Hölker, Franz; Franke, Steffen; Preuer, Torsten; Kloas, Werner

    2015-04-01

    Flora and fauna evolved under natural day and night cycles. However, natural light is now enhanced by artificial light at night, particularly in urban areas. This alteration of natural light environments during the night is hypothesised to alter biological rhythms in fish, by effecting night-time production of the hormone melatonin. Artificial light at night is also expected to increase the stress level of fish, resulting in higher cortisol production. In laboratory experiments, European perch (Perca fluviatilis) were exposed to four different light intensities during the night, 0 lx (control), 1 lx (potential light level in urban waters), 10 lx (typical street lighting at night) and 100 lx. Melatonin and cortisol concentrations were measured from water samples every 3h during a 24 hour period. This study revealed that the nocturnal increase in melatonin production was inhibited even at the lowest light level of 1 lx. However, cortisol levels did not differ between control and treatment illumination levels. We conclude that artificial light at night at very low intensities may disturb biological rhythms in fish since nocturnal light levels around 1 lx are already found in urban waters. However, enhanced stress induction could not be demonstrated.

  14. Factors affecting the incidence of postpartum oestrus, ovarian activity and reproductive performance in Thoroughbred mares bred at foal heat under Indian subtropical conditions.

    PubMed

    Sharma, Sumeet; Davies Morel, M C G; Dhaliwal, G S

    2010-07-01

    Decreased reproductive performance due to summer stress is a well known phenomenon in farm livestock. Whether this occurs in the mare and specifically how this might affect postpartum reproductive activity and performance, especially at Foal Heat (FH), is unknown. This study, therefore, aims to investigate this and the factors that might affect postpartum reproductive activity. Reproductive records of 228 Thoroughbred mares (694 mare years) bred in subtropical north-western India were retrospectively analysed. Overt oestrous activity occurred within 21 d postpartum in 92.94% (645/694) of mares. Significantly (p<0.001) more April foaling mares (97.37%, 185/190) expressed postpartum oestrous activity than those foaling in January (83.61%; 51/61) and February (88.49; 123/139). Similarly significantly (p<0.01) fewer multiparous mares failed to demonstrate oestrous activity than primiparous mares (6.12% vs.15.07%; 38/621 vs. 11/73, respectively). 190 of these 694 mares were additionally monitored to confirm ovulation; in these mares onset of FH (oestrus plus confirmed ovulation) occurred 8.42+/-0.17 d and first ovulation 13.64+/-0.20 d postpartum. Month, stud farm, year, and parity did not affect interval from parturition to FH onset or to first ovulation; or FH onset to ovulation. In FH bred mares Day 16 pregnancy rate and overall foaling rate were 53.76% (100/186) and 46.24% (86/186) respectively and were similar to those of mares bred later postpartum. FH pregnancy rates were not affected by stud, season, month, year, number of matings, or day of ovulation but were significantly (p<0.008) lowered by increasing mare age. Significantly (p<0.01) lower Day 16 pregnancy rates were observed in uterine treated mares compared to untreated mares (31.09% vs. 57.96%; 9/29 vs. 91/157, respectively), this difference was not evident during the rest of pregnancy. In conclusion, postpartum reproductive and ovarian activity appears to be affected by environment, i.e., delayed in

  15. Bacillus thuringiensis insecticidal crystal proteins affect lifespan and reproductive performance of Helicoverpa armigera and Spodoptera exigua adults.

    PubMed

    Zhang, Ying; Ma, Yan; Wan, Pin-Jun; Mu, Li-Li; Li, Guo-Qing

    2013-04-01

    Being delivered as sprays or expressed in plant, Bacillus thuringiensis (Bt) crystalline proteins (Cry toxins) display insecticidal activities against numerous Lepidopteran, Dipteran, and Coleopteran larvae. Comparative study of toxicities of Bt Cry toxins between larvae and adults may afford important new insights into the interactions of the toxins with receptor proteins in host insect, and represent intriguing targets for the control of insect pests. However, the effectiveness of Bt Cry toxins in insect adults has paid less attention. In the present article, the effectiveness of Cry1Ac and Cry1Ca on lifespans and reproductive performance of Helicoverpa armigera (Hübner) and Spodoptera exigua (Hübner) adults were evaluated by in vivo experiments. Considering transgenic plants express modified, truncated versions of cry genes yielding active toxin fragment, we used activated Bt toxins at the concentration of 500, 100, and 20 microg/ml in a 10% sucrose aquous solution. At the highest concentration, Cry1Ac and Cry1Ca shortened 48.1 and 48.9% of H. armigera female lifespan, and 43.5 and 38.5% of S. exigua female lifespan, and they reduced 37.8 and 40.3%, and 50.5 and 47.4% of H. armigera and S. exigua male lifespans respectively. Bt toxins negatively affected copulation. Exposure to 500 microg/ml of Cry1Ac and Cry1Ca greatly reduced 50.0 and 46.8%, and 58.7 and 57.3% spermatophore acceptance by H. armigera and S. exigua females, respectively. Similarly, Cry1Ac and Cry1Ca exposure decreased 40.0 and 50.3%, and 61.3 and 60.0% of spermatophore transfer by H. armigera and S. exigua males, respectively. Moreover, exposure females rather than males to 500 microg/ml of Cry1Ac and Cry1Ca significantly dropped 57.5 and 57.5% of the number of eggs laid by H. armigera, and 35.4 and 45.8% of the number of egg masses deposited by S. exigua. In contrast, both Cry1Ac and Cry1Ca did not negatively influence the egg hatchability. At the middle and the lowest concentrations, however

  16. The effect of ploidy and temporal changes in the biochemical profile of gibel carp (Carassius gibelio): a cyprinid fish species with dual reproductive strategies.

    PubMed

    Vetešník, Lukáš; Halačka, Karel; Simková, Andrea

    2013-04-01

    The basic biochemical profile of gibel carp (Carassius gibelio), diploid-triploid cyprinid species complex with dual reproduction modes, was investigated. The aim of the study was to test for the effect of fish group (which combines the effects of ploidy and sex) and temporal changes on indicators of the biochemical profile of blood in gibel carp. We showed that the basic biochemical profile of blood is significantly influenced by season and fish group. Triploid gynogenetic females had a better condition measured by total protein concentration than sexual diploids. The higher concentrations of triacylglycerols and cholesterol in triploid females when compared to diploids indicate a higher metabolic rate and higher energy intake during the whole year, which may represent a disadvantage for triploids. Differences in the concentrations of blood biochemical analytes between triploid females and diploids suggest a potential difference in the regulation of a wide range of physiological and biochemical processes in which these analytes participate. The biochemical profiles of two forms of C. gibelio could at least partially explain the changes of character of its naturally occurring populations.

  17. Behavior of steelhead fry in a laboratory stream is affected by fish density but not rearing environment

    USGS Publications Warehouse

    Riley, Stephen C.; Tatara, Christopher P.; Berejikian, Barry A.; Flagg, Thomas A.

    2009-01-01

    We quantified the aggression, feeding, dominance, position choice, and territory size of naturally reared steelhead Oncorhynchus mykiss fry stocked with two types of hatchery-reared fry (from conventional and enriched rearing environments) at two densities in experimental flumes to determine how rearing environment and fish density affect the behavior of steelhead fry. We found that fry density had a significant effect on most response variables but that rearing treatment did not. The rates of threats and attacks were positively correlated with fry density, but the overall feeding rate was negatively correlated. Naturally reared fry were dominant more often at low densities, and hatchery-reared fry were dominant more often at high densities. There were no significant effects of hatchery rearing treatment on aggression, feeding, dominance, or territory size. The only significant effect of rearing treatment was on the position of naturally reared fry, which occupied more upstream positions when stocked with conventional than with enriched hatchery-reared fry. Overall, rearing environment had relatively little influence on the behavior of steelhead fry. Our results indicate that stocking hatchery-reared steelhead fry at low densities may have effects on similar-size wild fish comparable to an equivalent increase in the density of wild fish. We suggest that releasing hatchery-reared steelhead fry as a supplementation strategy may have few direct negative ecological effects on wild fry.

  18. Acute exposure of a glyphosate-based herbicide affects the gills and liver of the Neotropical fish, Piaractus mesopotamicus.

    PubMed

    Shiogiri, Natália S; Paulino, Marcelo G; Carraschi, Silvia P; Baraldi, Flávia G; da Cruz, Claudinei; Fernandes, Marisa Narciso

    2012-09-01

    The aim of this study was to determine the acute toxicity of Roundup(®) Ready (RR) in Piaractus mesopotamicus, and evaluate the effects on the morphology of the gills and liver of exposed surviving fish. Fish were exposed to 3.0, 3.5, 4.0 and 4.5mgL(-1) of glyphosate, and the LC(50);48h was estimated at 3.74±0.2mgL(-1). Gill histopathology was rare, and the activity of Na(+)/K(+)-ATPase enzyme did not change, suggesting normal function. However, the damage to the liver was classified as moderate to severe. Cytoplasmic vacuolization, lipid accumulation, nuclear and cellular membrane alterations and glycogen depletion were found in the liver, suggesting a reduction in the liver function. The glyphosate in the RR formulation was classified as moderately toxic for P. mesopotamicus, and the severe damage in the liver may affect the detoxification and/or tissue repair process and contribute to fish death.

  19. Losing focus: how lens position and viewing angle affect the function of multifocal lenses in fishes.

    PubMed

    Gagnon, Yakir Luc; Wilby, David; Temple, Shelby Eric

    2016-09-01

    Light rays of different wavelengths are focused at different distances when they pass through a lens (longitudinal chromatic aberration [LCA]). For animals with color vision this can pose a serious problem, because in order to perceive a sharp image the rays must be focused at the shallow plane of the photoreceptor's outer segments in the retina. A variety of fish and tetrapods have been found to possess multifocal lenses, which correct for LCA by assigning concentric zones to correctly focus specific wavelengths. Each zone receives light from a specific beam entrance position (BEP) (the lateral distance between incoming light and the center of the lens). Any occlusion of incoming light at specific BEPs changes the composition of the wavelengths that are correctly focused on the retina. Here, we calculated the effect of lens position relative to the plane of the iris and light entering the eye at oblique angles on how much of the lens was involved in focusing the image on the retina (measured as the availability of BEPs). We used rotational photography of fish eyes and mathematical modeling to quantify the degree of lens occlusion. We found that, at most lens positions and viewing angles, there was a decrease of BEP availability and in some cases complete absence of some BEPs. Given the implications of these effects on image quality, we postulate that three morphological features (aphakic spaces, curvature of the iris, and intraretinal variability in spectral sensitivity) may, in part, be adaptations to mitigate the loss of spectral image quality in the periphery of the eyes of fishes.

  20. 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

  1. How HIV diagnosis and disclosure affect sexual behavior and relationships in Ugandan fishing communities.

    PubMed

    McArthur, Moriah; Birdthistle, Isolde; Seeley, Janet; Mpendo, Juliet; Asiki, Gershim

    2013-08-01

    In this article we examine how members of fishing communities on the shores of Lake Victoria in Uganda respond to HIV diagnosis in terms of disclosure to sexual partners. We then explore the subsequent changes in sexual behavior and relationships. To access this information, we collected life history data from 78 HIV-positive individuals in five fishing communities. We found that the strength of the sexual relationships shaped how and why individuals disclosed to partners, and that these relationships tended to be stronger when partners shared familial responsibility. Those who perceived their current sexual partnership to be weak sought to conceal their status by maintaining prediagnosis patterns of sexual behavior. The majority of the study's participants rarely changed their sexual behavior following HIV diagnosis, regardless of their relationship's strength. These findings elucidate barriers to disclosure and behavior change, and suggest that a life-course approach might enhance individual-level counseling so that counselors can provide tailored support to individuals regarding disclosure decisions and outcomes.

  2. Male Aedes aegypti mosquitoes use JH III transferred during copulation to influence previtellogenic ovary physiology and affect the reproductive output of female mosquitoes.

    PubMed

    Clifton, Mark E; Correa, Stefano; Rivera-Perez, Crisalejandra; Nouzova, Marcela; Noriega, Fernando G

    2014-05-01

    The effect of male accessory gland substances on female reproductive physiology has been previously described as "activating" egg development. However, no mechanism has been described that can explain how male mosquitoes are able to influence egg development in female mosquitoes. To investigate how male mosquitoes are able to influence ovarian physiology and reproductive output we explored three main questions: (1) Do mating and male accessory gland substances affect ovarian physiology and alter markers of oocyte quality during the previtellogenic resting stage? (2) Does the male accessory gland contain JH III and is JH III transferred to the female during copulation? (3) Finally, does the nutritional history of the male affect the amount of JH III transferred to the female and alter reproductive output? By answering these questions it is clear that male mosquitoes are able to alter the female's resource allocation priorities towards reproduction by transferring JH III during copulation; reducing the rate of previtellogenic resorption and increasing the amount of stored ovarian lipids. These changes improve an individual follicle's likelihood of development after a blood meal. In addition, males maintained under better nutritional conditions make and transfer more JH III, prevent more follicular resorption and realize higher fecundities than other males. Together these results illustrate one mechanism behind the "activating" effect of mating described as well as the role sugar feeding plays in male mosquitoes.

  3. Male Aedes aegypti mosquitoes use JH III transferred during copulation to influence previtellogenic ovary physiology and affect the reproductive output of female mosquitoes

    PubMed Central

    Clifton, Mark E.; Correa, Stefano; Rivera-Perez, Crisalejandra; Nouzova, Marcela; Noriega, Fernando G.

    2014-01-01

    The effect of male accessory gland substances on female reproductive physiology has been previously described as “activating” egg development. However, no mechanism has been described that can explain how male mosquitoes are able to influence egg development in female mosquitoes. To investigate how male mosquitoes are able to influence ovarian physiology and reproductive output we explored three main questions: 1) Do mating and male accessory gland substances affect ovarian physiology and alter markers of oocyte quality during the previtellogenic resting stage? 2) Does the male accessory gland contain JH III and is JH III transferred to the female during copulation? 3) Finally, does the nutritional history of the male affect the amount of JH III transferred to the female and alter reproductive output? By answering these questions it is clear that male mosquitoes are able to alter the female’s resource allocation priorities towards reproduction by transferring JH III during copulation; reducing the rate of previtellogenic resorption and increasing the amount of stored ovarian lipids. These changes improve an individual follicle’s likelihood of development after a blood meal. In addition, males maintained under better nutritional conditions make and transfer more JH III, prevent more follicular resorption and realize higher fecundities than other males. Together these results illustrate one mechanism behind the “activating” effect of mating described as well as the role sugar feeding plays in male mosquitoes. PMID:24657670

  4. The asymmetrical growth of otoliths in fish is affected by hypergravity.

    NASA Astrophysics Data System (ADS)

    Anken, R. H.; Kappel, T.; Rahmann, H.

    1999-12-01

    Size and asymmetry (size difference between the left and the right side) of inner ear otoliths of larval cichlid fish were determined after a long-term stay at moderate hypergravity conditions (3 g; centrifuge), in the course of which the animals completed their ontogenetic development from hatch to freely swimming. Both the normal morphogenetic development as well as the timely onset and gain of performance of the swimming behaviour was not impaired by the experimental conditions. However, both utricular and saccular otoliths (lapilli and sagittae, respectively) were significantly smaller after hyper- g exposure as compared to parallely raised 1 g control specimens. The asymmetry of sagittae was significantly increased in the experimental animals, whereas the respective asymmetry concerning lapilli was pronouncedly decreased in comparison to the 1 g controls. These findings suggest, that the growth and the development of bilateral asymmetry of otoliths is guided by the environmental gravity vector.

  5. A Comparison of Pathology Found in Three Marine Fish Treated with Endocrine Disrupting Compounds

    EPA Science Inventory

    Endocrine-disrupting chemicals (EDCs), such as the estrogen estradiol (E2) have been reported to affect fish reproduction. This study histopathologically compared and evaluated the effect of EDCs in three species of treated fish. Juvenile male summer flounder (Paralichthys dentat...

  6. Temperature and congener structure affect the enantioselectivity of toxaphene elimination by fish.

    PubMed

    Maruya, Keith A; Smalling, Kelly L; Vetter, Walter

    2005-06-01

    Recent advances in enantioselective separation techniques have enabled scientists to investigate environmental fate processes of chiral pollutants. In this study, congener- and enantiomer-specific toxaphene residues were monitored in captive, naturally contaminated fish (Fundulus heteroclitus) to characterize the effect of temperature and compound structure on the enantioselectivity of the elimination process. A previous study performed under warm water conditions (Tmean = 25 degrees C) demonstrated relatively rapid (t(1/2) approximately = 7-14 d) and enantioselective elimination of the reductive dechlorination metabolites 2-exo,3-endo,6-exo,8,9,-10-hexachlorobornane (B6-923 or Hx-Sed) and 2-endo,3-exo,5-endo,6-exo,8,9,10-heptachlorobornane (B7-1001 or Hp-Sed). As expected, repetition of this experiment at cooler water temperatures (Tmean = 15 degrees C) resulted in a decrease in overall (i.e., both enantiomers) first-order elimination rate constants. Enantiomer fractions or ratios (EFs/ERs) during elimination, however, varied by congener, ranging from racemic for very rapidly eliminated Cl5 homologues to increasingly nonracemic for selected Cl6-Cl8 homologues (including 86-923, several unknown Cl7 compounds, B8-1414, and B8-1945). As a result, we propose a classification to describe the environmental persistence of chiral toxaphene pollutants based on congener-specific elimination kinetics and susceptibility to biotransformation as measured by EFs/ERs.

  7. Ultraviolet radiation affects invasibility of lake ecosystems by warm-water fish.

    PubMed

    Tucker, Andrew J; Williamson, Craig E; Rose, Kevin C; Oris, James T; Connelly, Sandra J; Olson, Mark H; Mitchell, David L

    2010-03-01

    Predicting where species invasions will occur remains a substantial challenge in ecology, but identifying factors that ultimately constrain the distribution of potential invaders could facilitate successful prediction. Whereas ultraviolet radiation (UVR) is recognized as an important factor controlling species distribution and community composition, the role of UVR in a habitat invasibility context has not been explored. Here we examine how underwater UVR can regulate warm-water fish invasion. In Lake Tahoe, California and Nevada, USA, established populations of exotic bluegill sunfish (Lepomis macrochirus) are currently limited to turbid, low-UVR embayments. An in situ incubation experiment that manipulated incident UVR exposure of larval bluegill, combined with an assessment of UVR exposure levels in nearshore habitats around Lake Tahoe, demonstrates that UVR can mediate habitat invasibility. Our findings suggest that the susceptibility to invasion by UVR sensitive species may increase in transparent aquatic systems threatened by declining water quality, and they highlight the importance of abiotic factors as regulators of invasion risk in ecosystems.

  8. Actions of sex steroids on kisspeptin expression and other reproduction-related genes in the brain of the teleost fish European sea bass.

    PubMed

    Alvarado, M V; Servili, A; Molés, G; Gueguen, M M; Carrillo, M; Kah, O; Felip, A

    2016-11-01

    Kisspeptins are well known as mediators of the coordinated communication between the brain-pituitary axis and the gonads in many vertebrates. To test the hypothesis that gonadal steroids regulate kiss1 and kiss2 mRNA expression in European sea bass (a teleost fish), we examined the brains of gonad-intact (control) and castrated animals, as well as castrated males (GDX) and ovariectomized females (OVX) that received testosterone (T) and estradiol (E2) replacement, respectively, during recrudescence. In GDX males, low expression of kiss1 mRNA is observed by in situ hybridization in the caudal hypothalamus (CH) and the mediobasal hypothalamus (MBH), although hypothalamic changes in kiss1 mRNA levels were not statistically different among the groups, as revealed by real-time PCR. However, T strongly decreased kiss2 expression levels in the hypothalamus, which was documented in the MBH and the nucleus of the lateral recess (NRLd) in GDX T-treated sea bass males. Conversely, it appears that E2 evokes low kiss1 mRNA in the CH, while there were cells expressing kiss2 in the MBH and NRLd in these OVX females. These results demonstrate that kisspeptin neurons are presumably sensitive to the feedback actions of sex steroids in the sea bass, suggesting that the MBH represents a major site for sex steroid actions on kisspeptins in this species. Also, recent data provide evidence that both positive and negative actions occur in key factors involved in sea bass reproductive function, including changes in the expression of gnrh-1/gonadotropin, cyp19b, er and ar genes and sex steroid and gonadotropin plasma levels in this teleost fish.

  9. Exposure to advertisement calls of reproductive competitors activates vocal-acoustic and catecholaminergic neurons in the plainfin midshipman fish, Porichthys notatus.

    PubMed

    Petersen, Christopher L; Timothy, Miky; Kim, D Spencer; Bhandiwad, Ashwin A; Mohr, Robert A; Sisneros, Joseph A; Forlano, Paul M

    2013-01-01

    While the neural circuitry and physiology of the auditory system is well studied among vertebrates, far less is known about how the auditory system interacts with other neural substrates to mediate behavioral responses to social acoustic signals. One species that has been the subject of intensive neuroethological investigation with regard to the production and perception of social acoustic signals is the plainfin midshipman fish, Porichthys notatus, in part because acoustic communication is essential to their reproductive behavior. Nesting male midshipman vocally court females by producing a long duration advertisement call. Females localize males by their advertisement call, spawn and deposit all their eggs in their mate's nest. As multiple courting males establish nests in close proximity to one another, the perception of another male's call may modulate individual calling behavior in competition for females. We tested the hypothesis that nesting males exposed to advertisement calls of other males would show elevated neural activity in auditory and vocal-acoustic brain centers as well as differential activation of catecholaminergic neurons compared to males exposed only to ambient noise. Experimental brains were then double labeled by immunofluorescence (-ir) for tyrosine hydroxylase (TH), an enzyme necessary for catecholamine synthesis, and cFos, an immediate-early gene product used as a marker for neural activation. Males exposed to other advertisement calls showed a significantly greater percentage of TH-ir cells colocalized with cFos-ir in the noradrenergic locus coeruleus and the dopaminergic periventricular posterior tuberculum, as well as increased numbers of cFos-ir neurons in several levels of the auditory and vocal-acoustic pathway. Increased activation of catecholaminergic neurons may serve to coordinate appropriate behavioral responses to male competitors. Additionally, these results implicate a role for specific catecholaminergic neuronal groups in

  10. Aspects of the hormonal regulation of appetite in fish with emphasis on goldfish, Atlantic cod and winter flounder: notes on actions and responses to nutritional, environmental and reproductive changes.

    PubMed

    Volkoff, Hélène; Xu, Meiyu; MacDonald, Erin; Hoskins, Leah

    2009-05-01

    In vertebrates including fish, food intake regulation involves intricate networks of hormones produced by both brain and peripheral tissues. Under optimum conditions, nutritional intake is adequate for basal metabolic needs, growth, development, reproduction, and deposition of energy stores. As fish represent a very diverse group, different fish species live in very different environments and are exposed to variations in a wide range of factors, including not only internal factors, such as nutritional/metabolic status and reproductive events but also environmental factors, such as temperature and photoperiod. These physiological responses often include changes in appetite that might occur through modulations of the gene expression and action of feeding-regulating hormones. Despite recent advances, our current understanding of the regulation of feeding in fish is still limited and based primarily on studies involving a few fish species. This review will give a brief overview of our current knowledge of the regulation of feeding by three central (NPY, OX and CART) and two peripheral (ghrelin and GRP) appetite-related factors in a freshwater species, the goldfish (Carassius auratus) and two marine species, cod (Gadus morhua) and winter flounder (Pleuronectes americanus).

  11. Spatial heterogeneity in the Mediterranean Biodiversity Hotspot affects barcoding accuracy of its freshwater fishes.

    PubMed

    Geiger, M F; Herder, F; Monaghan, M T; Almada, V; Barbieri, R; Bariche, M; Berrebi, P; Bohlen, J; Casal-Lopez, M; Delmastro, G B; Denys, G P J; Dettai, A; Doadrio, I; Kalogianni, E; Kärst, H; Kottelat, M; Kovačić, M; Laporte, M; Lorenzoni, M; Marčić, Z; Özuluğ, M; Perdices, A; Perea, S; Persat, H; Porcelotti, S; Puzzi, C; Robalo, J; Šanda, R; Schneider, M; Šlechtová, V; Stoumboudi, M; Walter, S; Freyhof, J

    2014-11-01

    Incomplete knowledge of biodiversity remains a stumbling block for conservation planning and even occurs within globally important Biodiversity Hotspots (BH). Although technical advances have boosted the power of molecular biodiversity assessments, the link between DNA sequences and species and the analytics to discriminate entities remain crucial. Here, we present an analysis of the first DNA barcode library for the freshwater fish fauna of the Mediterranean BH (526 spp.), with virtually complete species coverage (498 spp., 98% extant species). In order to build an identification system supporting conservation, we compared species determination by taxonomists to multiple clustering analyses of DNA barcodes for 3165 specimens. The congruence of barcode clusters with morphological determination was strongly dependent on the method of cluster delineation, but was highest with the general mixed Yule-coalescent (GMYC) model-based approach (83% of all species recovered as GMYC entity). Overall, genetic morphological discontinuities suggest the existence of up to 64 previously unrecognized candidate species. We found reduced identification accuracy when using the entire DNA-barcode database, compared with analyses on databases for individual river catchments. This scale effect has important implications for barcoding assessments and suggests that fairly simple identification pipelines provide sufficient resolution in local applications. We calculated Evolutionarily Distinct and Globally Endangered scores in order to identify candidate species for conservation priority and argue that the evolutionary content of barcode data can be used to detect priority species for future IUCN assessments. We show that large-scale barcoding inventories of complex biotas are feasible and contribute directly to the evaluation of conservation priorities.

  12. Reproductive allocation in plants as affected by elevated carbon dioxide and other environmental changes: a synthesis using meta-analysis and graphical vector analysis.

    PubMed

    Wang, Xianzhong; Taub, Daniel R; Jablonski, Leanne M

    2015-04-01

    Reproduction is an important life history trait that strongly affects dynamics of plant populations. Although it has been well documented that elevated carbon dioxide (CO2) in the atmosphere greatly enhances biomass production in plants, the overall effect of elevated CO2 on reproductive allocation (RA), i.e., the proportion of biomass allocated to reproductive structures, is little understood. We combined meta-analysis with graphical vector analysis to examine the overall effect of elevated CO2 on RA and how other environmental factors, such as low nutrients, drought and elevated atmospheric ozone (O3), interacted with elevated CO2 in affecting RA in herbaceous plants. Averaged across all species of different functional groups and environmental conditions, elevated CO2 had little effect on RA (-0.9%). RA in plants of different reproductive strategies and functional groups, however, differed in response to elevated CO2. For example, RA in iteroparous wild species decreased by 8%, while RA in iteroparous crops increased significantly (+14%) at elevated CO2. RA was unaffected by CO2 in plants grown with no stress or in low-nutrient soils. RA decreased at elevated CO2 and elevated O3, but increased in response to elevated CO2 in drought-stressed plants, suggesting that elevated CO2 could ameliorate the adverse effect of drought on crop production to some extent. Our results demonstrate that elevated CO2 and other global environmental changes have the potential to greatly alter plant community composition through differential effects on RA of different plant species and thus affect the dynamics of natural and agricultural ecosystems in the future.

  13. Biology of the harlequin fish Othos dentex (Serranidae), with particular emphasis on sexual pattern and other reproductive characteristics.

    PubMed

    French, B; Potter, I C; Hesp, S A; Coulson, P G; Hall, N G

    2014-01-01

    Key biological characteristics of the harlequin fish Othos dentex, a representative of a monospecific genus of the Anthiinae (Serranidae), were determined from samples collected around reefs on the south coast of Western Australia. The females of this relatively long-lived species (maximum recorded age in this study = 37 years) attained only a slightly greater maximum total length and age than males and neither the length nor the age-frequency distributions showed a conspicuous sex-based bimodality. Furthermore, gonads from a wide size and age range of O. dentex were shown by histology, at several locations along their length, to always comprise exclusively either ovarian or testicular tissues. Thus, O. dentex is a gonochorist, a sexual pattern only previously recorded definitively for one other anthiine serranid, i.e. Epinephelides armatus, which also occurs in south-western Australia. Similar to E. armatus, O. dentex possesses 'solid' testes with a central sperm duct, thereby differing in structure from those typically found in serranids, in which there is a central membrane-bound 'ovarian' lumen and peripherally located sperm sinuses. The gonadal characteristics and sexual pattern of these two gonochoristic anthiines are not consistent with a recent proposal for the trends exhibited by the evolution of gonochorism and protogyny within the Serranidae. Othos dentex has indeterminate fecundity and a protracted spawning period (7 months) and, on the basis of underwater observations and a low gonado-somatic index (I(G)) for males, is a pair spawner, which is unusual for a gonochorist of a serranid or member of a related family. While the large spots on the lower half of the body of O. dentex are shown quantitatively to be similarly yellow in juveniles and adult females, they then become blue in males at maturity and this intensifies during the spawning period, when they presumably play an important role in agonistic interactions among males and courtship with

  14. Factors affecting reproductive success and life history parameters of Bracon hebetor Say (Hymenoptera: Braconidae) from three host-associated populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Augmentative releases of native natural enemies are viable strategies for suppression of crop pests. Appropriate mass rearing and release strategies rely on a thorough understanding of the reproductive biology of the natural enemy. In the present study, we evaluated the effects of parasitoid source ...

  15. Factors affecting reproductive success and life history parameters of Bracon hebetor Say (Hymenoptera: Braconidae) from three host-associated populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Augmentative releases of native natural enemies are viable strategies for suppression of crop pests. Appropriate mass rearing and release strategies rely on a thorough understanding of the reproductive biology of the natural enemy. In the present study, we evaluated the effects of parasitoid sourc...

  16. Aromatase activity in hindbrain vocal control region of a teleost fish: divergence amoung males with alternative reproductive tactics

    PubMed Central

    Schlinger, B. A.; Greco, C.; Bass, A. H.

    1999-01-01

    Type I male midshipman fish acoustically court females, whereas type II males do not but instead sneak or satellite spawn to compete with type I males for fertilizations. 'Singing' type I males diverge from type II males and females in the organization of an expansive hindbrain pacemaker–motoneuron circuit that establishes the physical attributes of vocalizations. Here, levels of aromatase activity were determined in homogenates of brain by measuring the conversion of 3H-androstenedione (AE) to 3H-oestrone (E1) and 3H-oestradiol (E2). Levels were highest in the telencephalon–preoptic area and similar for all morphs. Lower levels were in a region including the diencephalon, midbrain and cerebellum, although levels were significantly higher in females compared with type I males. In the vocal hindbrain region, aromatase levels were three- to five-fold higher in type II males and females than in type I males, and in castrated type II males than in castrated type I males. Conversion of testosterone to oestrogen in type II males and females may effectively prevent testosterone-induced maturation of the vocal system that characterizes type I males. Aromatase may thus be a key enzyme regulating the expression of individual-specific brain circuitry and behaviours among members of one sex.

  17. Individual experience and evolutionary history of predation affect expression of heritable variation in fish personality and morphology.

    PubMed

    Dingemanse, Niels J; Van der Plas, Fons; Wright, Jonathan; Réale, Denis; Schrama, Maarten; Roff, Derek A; Van der Zee, Els; Barber, Iain

    2009-04-07

    Predation plays a central role in evolutionary processes, but little is known about how predators affect the expression of heritable variation, restricting our ability to predict evolutionary effects of predation. We reared families of three-spined stickleback Gasterosteus aculeatus from two populations-one with a history of fish predation (predator sympatric) and one without (predator naive)-and experimentally manipulated experience of predators during ontogeny. For a suite of ecologically relevant behavioural ('personality') and morphological traits, we then estimated two key variance components, additive genetic variance (VA) and residual variance (VR), that jointly shape narrow-sense heritability (h2=VA/(VA+VR)). Both population and treatment differentially affected VA versus VR, hence h2, but only for certain traits. The predator-naive population generally had lower VA and h2 values than the predator-sympatric population for personality behaviours, but not morphological traits. Values of VR and h2 were increased for some, but decreased for other personality traits in the predator-exposed treatment. For some personality traits, VA and h2 values were affected by treatment in the predator-naive population, but not in the predator-sympatric population, implying that the latter harboured less genetic variation for behavioural plasticity. Replication and experimental manipulation of predation regime are now needed to confirm that these population differences were related to variation in predator-induced selection. Cross-environment genetic correlations (rA) were tight for most traits, suggesting that predator-induced selection can affect the evolution of the same trait expressed in the absence of predators. The treatment effects on variance components imply that predators can affect evolution, not only by acting directly as selective agents, but also by influencing the expression of heritable variation.

  18. Population growth, trophic level, and reproductive biology of two congeneric archer fishes (Toxotes chatareus, Hamilton 1822 and Toxotes jaculatrix, Pallas 1767) inhabiting Malaysian coastal waters.

    PubMed

    Simon, K D; Bakar, Y; Samat, A; Zaidi, C C; Aziz, A; Mazlan, A G

    2009-12-01

    Population growth, trophic level, and some aspects of reproductive biology of two congeneric archer fish species, Toxotes chatareus and Toxotes jaculatrix, collected from Johor coastal waters, Malaysia, were studied. Growth pattern by length-weight relationship (W=aL(b)) for the sexes differed, and exhibited positive allometric growth (male, female and combined sexes of T. chatareus; female and combined sexes of T. jaculatrix) and isometric growth (male samples of T. jaculatrix only). Trophic levels of both species were analyzed based on 128 specimens. The results show that, in both species, crustaceans and insects were the most abundant prey items, and among crustaceans the red clawed crab Sesarma bidens and Formicidae family insects were the most represented taxa. The estimated mean trophic levels for T. chatareus and T. jaculatrix were 3.422+/-0.009 and 3.420+/-0.020, respectively, indicating that they are largely carnivores. Fecundity of T. chatareus ranged from 38 354 to 147 185 eggs for females with total length ranging from 14.5 to 22.5 cm and total body weight from 48.7 to 270.2 g, and T. jaculatrix 25 251 to 150 456 eggs for females with total length ranging from 12.2 to 23.0 cm and total body weight from 25.7 to 275.0 g. Differences in values of gonadosomatic and hepatosomatic indexes calculated for both species in this study may have resulted from uneven sample size ranges.

  19. The effect of 17α-ethynylestradiol on steroidogenesis and gonadal cytokine gene expression is related to the reproductive stage in marine hermaphrodite fish.

    PubMed

    Cabas, Isabel; Chaves-Pozo, Elena; García-Alcázar, Alicia; Meseguer, José; Mulero, Victoriano; García-Ayala, Alfonsa

    2013-12-11

    Pollutants have been reported to disrupt the endocrine system of marine animals, which may be exposed through contaminated seawater or through the food chain. Although 17α-ethynylestradiol (EE₂), a drug used in hormone therapies, is widely present in the aquatic environment, current knowledge on the sensitivity of marine fish to estrogenic pollutants is limited. We report the effect of the dietary intake of 5 µg EE₂/g food on different processes of testicular physiology, ranging from steroidogenesis to pathogen recognition, at both pre-spermatogenesis (pre-SG) and spermatogenesis (SG) reproductive stages, of gilthead seabream (Sparus aurata L.), a marine hermaphrodite teleost. A differential effect between pre-SG and SG specimens was detected in the sex steroid serum levels and in the expression profile of some steroidogenic-relevant molecules, vitellogenin, double sex- and mab3-related transcription factor 1 and some hormone receptors. Interestingly, EE₂ modified the expression pattern of some immune molecules involved in testicular physiology. These differences probably reflect a developmental adjustment of the sensitivity to EE₂ in the gilthead seabream gonad.

  20. The Effect of 17α-Ethynylestradiol on Steroidogenesis and Gonadal Cytokine Gene Expression Is Related to the Reproductive Stage in Marine Hermaphrodite Fish

    PubMed Central

    Cabas, Isabel; Chaves-Pozo, Elena; García-Alcázar, Alicia; Meseguer, José; Mulero, Victoriano; García-Ayala, Alfonsa

    2013-01-01

    Pollutants have been reported to disrupt the endocrine system of marine animals, which may be exposed through contaminated seawater or through the food chain. Although 17α-ethynylestradiol (EE2), a drug used in hormone therapies, is widely present in the aquatic environment, current knowledge on the sensitivity of marine fish to estrogenic pollutants is limited. We report the effect of the dietary intake of 5 µg EE2/g food on different processes of testicular physiology, ranging from steroidogenesis to pathogen recognition, at both pre-spermatogenesis (pre-SG) and spermatogenesis (SG) reproductive stages, of gilthead seabream (Sparus aurata L.), a marine hermaphrodite teleost. A differential effect between pre-SG and SG specimens was detected in the sex steroid serum levels and in the expression profile of some steroidogenic-relevant molecules, vitellogenin, double sex- and mab3-related transcription factor 1 and some hormone receptors. Interestingly, EE2 modified the expression pattern of some immune molecules involved in testicular physiology. These differences probably reflect a developmental adjustment of the sensitivity to EE2 in the gilthead seabream gonad. PMID:24335523

  1. Evaluation of quantitative trait loci affecting intramuscular fat and reproductive traits in pigs using marker-assisted introgression.

    PubMed

    Sato, S; Ohnishi, C; Kikuchi, T; Kohira, K; Egawa, S; Terai, S; Nakamura, T; Arata, S; Komatsuda, A; Uemoto, Y

    2014-12-01

    We investigated the effects of previously identified quantitative trait loci (QTL) in an experimental backcross (BC) between Chinese Meishan pigs and commercial Duroc pigs. We performed marker-assisted introgression of two QTL for intramuscular fat (IMF) content (IMF population) and three QTL for reproductive traits (reproduction population) from a donor Meishan pig into a recipient Duroc pig. At the fourth BC generation of the IMF population and third BC generation of the reproduction population, carrier animals were selected for the production of animals homozygous for the QTL. Our previous studies have shown that the presence of a Meishan allele on the IMF QTL is associated with low IMF values, and the Meishan allele on the reproductive QTL is associated with large litters. In this study, the presence of a Duroc allele at the IMF QTL on SSC9 resulted in a 0.27% increase in IMF (additive effect = 0.27 ± 0.08), whereas the presence of a Meishan allele at the IMF QTL on SSC7 resulted in a 0.34% increase in IMF (additive effect = -0.34 ± 0.09). The presence of the Meishan allele at the IMF QTL on SSC7 thus had the opposite effect to our previous studies, that is, increased IMF. In the reproduction population, we observed no differences between the genotypes of the three QTL in regard to number of corpora lutea or litter size. Marker-assisted introgression at these QTL is thus unlikely to result in an associated increase in litter size. These results show that it is possible to introgress alleles from other breeds into a selection population using molecular markers; any unexpected results might be associated with the genetic background.

  2. Effect of aqueous extract of Azadirachta indica A. Juss (neem) leaf on oocyte maturation, oviposition, reproductive potentials and embryonic development of a freshwater fish ectoparasite Argulus bengalensis Ramakrishna, 1951 (Crustacea: Branchiura).

    PubMed

    Banerjee, Anirban; Manna, Subha; Saha, Samar Kumar

    2014-12-01

    In present study, a microcosm experiment is carried out to investigate the efficacy of 120 and 250-ppm crude aqueous extract of Azadirachta leaf on oocyte maturation, oviposition, embryonic development and hatching of the eggs of a fish ectoparasite Argulus bengalensis. Relative abundance of different maturing oocyte stages in the ovary of the parasite from different age groups was enumerated, and marked variations were obtained. Significant depletion in the abundance of pre-vitollogenic, vitellogenic and post-vitellogenic oocytes was recorded, which indicates impairment in maturation. Chromatin condensation of the oocytes of treated parasite indicates apoptosis of oogenic cells. Strong oviposition deterrence was evident by the elevated oviposition deterrence index of 0.18 and 0.52 at respective toxin levels. The treated parasites invested less number of eggs per oviposition, and hatching percentage of the eggs reduced markedly. In vitro treatment of eggs within 70 min of incubation exhibited coagulation of yolk material and subsequent reduction in hatching percentage. However, treatment applied after this critical period, hatching was not significantly altered. In vitro treatment of eggs at 80 min of incubation resulted in normal development. It signifies that azadirachtin affects the early developmental events but not the later. Presumably, azadirachtin either affects early gene expression of the embryo or antagonizes any of the substances of the zygote required for sustaining early developmental process. The result of the present experiment suggests that azadirachtin could be a promising agent to control argulosis through inhibition of the reproductive maturity of the parasite as well as through interference of its embryonic development.

  3. Effects of dietary methylmercury on reproduction of fathead minnows

    USGS Publications Warehouse

    Hammerschmidt, C.R.; Sandheinrich, M.B.; Wiener, J.G.; Rada, R.G.

    2002-01-01

    We examined effects of dietary methylmercury (MeHg) on reproduction of fathead minnows (Pimephales promelas). Juvenile fish were fed one of four diets until sexual maturity (phase 1): a control diet (0.06 μg Hg g-1 dry weight) and three diets contaminated with MeHg at 0.88 (low), 4.11 (medium), and 8.46 μg Hg g-1 dry weight (high). At sexual maturity, male and female fish were paired, again fed one of the four diets, and allowed to reproduce (phase 2). To assess effects of MeHg during gametogenesis, some fish were fed diets during phase 2 that differed from those during phase 1. Spawning success of pairs fed the same diet during phases 1 and 2 was 75% for controls and 46%, 50%, and 36% for the low-, medium-, and high-MeHg treatments, respectively. Spawning success of pairs fed a contaminated diet during phase 1 and a control diet during phase 2 was 63%, 40%, and 14% for the low-, medium-, and high-MeHg treatments, respectively, whereas exposure to dietary MeHg only during phase 2 did not reduce spawning success. Dietary MeHg delayed spawning, and days to spawning was positively correlated with concentration of total mercury in the carcasses of test fish. MeHg reduced the instantaneous rate of reproduction of fish fed the same diets during phases 1 and 2. Both the gonadosomatic index and reproductive effort of female fish were inversely correlated with mercury in carcasses, whereas developmental and hatching success of embryos, 7-d survival, and 7-d growth of larvae were unrelated to mercury concentrations in parental fish or their diets. MeHg decreased reproduction of adult fathead minnows at dietary concentrations encountered by predatory fishes in aquatic systems with MeHg-contaminated food webs, implying that exposed fish populations could be adversely affected by this widespread contaminant.

  4. High levels of maternally transferred mercury do not affect reproductive output or embryonic survival of northern watersnakes (Nerodia sipedon).

    PubMed

    Chin, Stephanie Y; Willson, John D; Cristol, Daniel A; Drewett, David V V; Hopkins, William A

    2013-03-01

    Maternal transfer is an important exposure pathway for contaminants because it can directly influence offspring development. Few studies have examined maternal transfer of contaminants, such as mercury (Hg), in snakes, despite their abundance and high trophic position in many ecosystems where Hg is prevalent. The objectives of the present study were to determine if Hg is maternally transferred in northern watersnakes (Nerodia sipedon) and to evaluate the effects of maternal Hg on reproduction. The authors captured gravid female watersnakes (n = 31) along the South River in Waynesboro, Virginia, USA, where an extensive Hg-contamination gradient exists. The authors measured maternal tissue and litter Hg concentrations and, following birth, assessed (1) reproductive parameters (i.e., litter size and mass, neonate mass); (2) rates of infertility, death during development, stillbirths, malformations, and runts; and (3) the overall viability of offspring. Mercury concentrations in females were strongly and positively correlated with concentrations in litters, suggesting that N. sipedon maternally transfer Hg in proportion to their tissue residues. Maternal transfer resulted in high concentrations (up to 10.10 mg/kg dry wt total Hg) of Hg in offspring. The authors found little evidence of adverse effects of Hg on these measures of reproductive output and embryonic survival, suggesting that N. sipedon may be more tolerant of Hg than other vertebrate species. Given that this is the first study to examine the effects of maternally transferred contaminants in snakes and that the authors did not measure all reproductive endpoints, further research is needed to better understand factors that influence maternal transfer and associated sublethal effects on offspring.

  5. Concurrence of Iridovirus, Polyomavirus, and a Unique Member of a New Group of Fish Papillomaviruses in Lymphocystis Disease-Affected Gilthead Sea Bream

    PubMed Central

    López-Bueno, Alberto; Mavian, Carla; Labella, Alejandro M.; Castro, Dolores; Borrego, Juan J.; Alcami, Antonio

    2016-01-01

    ABSTRACT Lymphocystis disease is a geographically widespread disease affecting more than 150 different species of marine and freshwater fish. The disease, provoked by the iridovirus lymphocystis disease virus (LCDV), is characterized by the appearance of papillomalike lesions on the skin of affected animals that usually self-resolve over time. Development of the disease is usually associated with several environmental factors and, more frequently, with stress conditions provoked by the intensive culture conditions present in fish farms. In gilthead sea bream (Sparus aurata), an economically important cultured fish species in the Mediterranean area, a distinct LCDV has been identified but not yet completely characterized. We have used direct sequencing of the virome of lymphocystis lesions from affected S. aurata fish to obtain the complete genome of a new LCDV-Sa species that is the largest vertebrate iridovirus sequenced to date. Importantly, this approach allowed us to assemble the full-length circular genome sequence of two previously unknown viruses belonging to the papillomaviruses and polyomaviruses, termed Sparus aurata papillomavirus 1 (SaPV1) and Sparus aurata polyomavirus 1 (SaPyV1), respectively. Epidemiological surveys showed that lymphocystis disease was frequently associated with the concurrent appearance of one or both of the new