Journal of Fish Biology
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Normal axial skeleton structure in common roach Rutilus rutilus (Actinopterygii: Cyprinidae) and malformations due to radiation contamination in the area of the Mayak (Chelyabinsk Province, Russia) nuclear plant
Journal of Fish Biology - Tập 79 Số 4 - Trang 991-1016 - 2011
Delayed consequences of extremely low‐frequency magnetic fields and the influence of adverse environmental conditions on roach <i>Rutilus rutilus</i> embryos This study presents data collected over a 6 year period on the effects of extremely low‐frequency magnetic fields (MFs ) (1·4–1·6 µT , 500 Hz and 1·4–1·6 µT , 72·5 Hz) and MFs in combination with other environmental stressors (elevated temperature, 0·01 mg l−1 trichlorfon, 0·01 mg l−1 copper sulphate pentahydrate) on roach Rutilus rutilus embryos. Effects were studied during different stages of early development. Rutilus rutilus were raised in ponds for 4 months after exposure to MFs . The mass, standard length (L S ) and morphological characteristics of underyearlings which were exposed as embryos were recorded. An increase in embryo mortality and a decrease in L S and mass indices in underyearlings were noted after they had been exposed to a combination of MFs and different adverse environmental factors. In addition, exposure to MFs led to changes in the total number of vertebrae and the number of seismosensory system openings in the mandibular bones of underyearlings. MFs of different frequency caused both increases (500 Hz) and decreases (72·5 Hz) in morphological diversity. The stressors used in this study, however, did not increase the fluctuating asymmetry of bilateral morphological characteristics. The possible microevolutionary effects of exposure to MFs alone and in combination with other adverse environmental factors upon natural fish populations are discussed.
Journal of Fish Biology - Tập 88 Số 4 - Trang 1283-1300 - 2016
Dispersal patterns and status change in a co‐operatively breeding cichlid<i>Neolamprologus pulcher</i>: evidence from microsatellite analyses and behavioural observations Genetic techniques and long‐term behavioural observations were combined to investigate dispersal patterns and changes in social position inNeolamprologus pulcher , a co‐operatively breeding cichlid from Lake Tanganyika. Comparisons of genetic variance (F ST ) across sub‐populations demonstrated that fish were genetically more similar to individuals from proximate sub‐populations compared to individuals from distant sub‐populations. Microsatellite analyses revealed year‐long philopatry for some individuals and that other individuals dispersed to new territories and sub‐populations. Individuals appeared to disperse farther (across many territories in a sub‐population or to new sub‐populations) to achieve breeding status. Non‐breeding group members (or helpers) were observed to inherit breeding positions and male breeders were replaced faster than female breeders. These results demonstrate that important and difficult to obtain life‐history information can be obtained from genetic sampling.
Journal of Fish Biology - Tập 65 Số 1 - Trang 91-105 - 2004
Maturation of female common snook <i>Centropomus undecimalis</i>: implications for managing protandrous fishes Abstract The assumption for hermaphroditic fish species that mature individuals of the terminal sex arise directly from mature individuals of the primary sex has led to the use of sex ratios as a proxy for age at maturity (A 50 ). The timing of transition and deficient energy reserves, however, can result in a delay between transition and spawning. To test the assumption of female maturity and investigate the relationship between maturation and energy reserves, common snook, Centropomus undecimalis , a protandrous hermaphrodite, were collected from rivers, estuaries, inlets and offshore habitats on the east coast of Florida during 2010–2015. Immature females were observed every month, with lowest proportions during the peak spawning months of July and August. When calculated based on sex ratio, A 50 (8.1 years) overestimated the age at which 50% of the female population was, in fact, mature (4.1–4.9 years). Best‐fit models indicate that mesenteric fat index (I F ) and hepato‐somatic index (I H ) were significantly affected by gonad phase, month and size and weakly by habitat. In post hoc analysis, immature female I F did not differ significantly from developing and regenerating females, but immature female I H was significantly lower than that for all mature phases except animals in the regressing phase. Although immature females may have sufficient energy in terms of fat, it appears that energy is not allocated to reproductive processes, as evidenced by lower I H . Nonetheless, approximately 95% of females were spawning‐capable during peak spawning months, suggesting that the energy threshold at which immature females reach maturity is met by most females each spawning cycle.
Journal of Fish Biology - Tập 97 Số 5 - Trang 1317-1331 - 2020
Twenty years of invasion: a review of round goby<i>Neogobius melanostomus</i>biology, spread and ecological implications The round gobyNeogobius melanostomus is one of the most wide‐ranging invasive fish on earth, with substantial introduced populations within the Laurentian Great Lakes watershed, the Baltic Sea and several major European rivers. Rapid expansion and deleterious ecosystem effects have motivated extensive research on this species; here this research is synthesized. Maps of the global distribution are provided and the invasion history ofN. melanostomus , which spread more rapidly at first in North America, but has undergone substantial expansion over the past decade in the Baltic Sea, is summarized. Meta‐analyses comparing their size at age, diet, competitors and predators in North American and European ecosystems are provided. Size at age is region specific, with saline habitats typically supporting larger and faster growing individuals than fresh water.Neogobius melanostomus prey differs substantially between regions, demonstrating a capacity to adapt to locally abundant food sources.Neogobius melanostomus comprise at least 50% of the diet of eight taxa in at least one site or life stage; in total, 16 predator taxa are documented from the Laurentian Great Lakesv. five from Eurasia. InvasiveN. melanostomus are the only common forage fish to heavily exploit mussels in the Laurentian Great Lakes and the Baltic Sea, facilitating the transfer of energy from mussels to higher trophic levels in both systems.Neogobius melanostomus morphology, life history, reproduction, habitat preferences, environmental tolerances, parasites, environmental effects, sampling strategies and management are also discussed.Neogobius melanostomus inhabit a wide range of temperate freshwater and brackish‐water ecosystems and will probably continue to spreadvia ballast water, accidental bait release and natural dispersal worldwide. Climate change will probably enhanceN. melanostomus expansion by elevating water temperatures closer to its energetic optimum of 26° C. Future research needs are presented; most pressing are evaluating the economic effects ofN. melanostomus invasion, determining long‐term population level effects of egg predation on game‐fish recruitment and comparing several variables (density, ecological effects morphology and life history) among invaded ecosystems. This review provides a central reference as researchers continue studyingN. melanostomus , often as examples for advancing basic ecology and invasion biology.
Journal of Fish Biology - Tập 80 Số 2 - Trang 235-285 - 2012
The toxicity of iron to brown trout and effects on the gills: a comparison of two grades of iron sulphate The 96‐h LC50 on brown trout Salmo trutta of a commercial iron (III) sulphate liquor, used for treating reservoirs to reduce algal growth, was 28 mg total Fe l−1 (0·05 mg soluble Fe l−1 ). The 96‐h LC50 for analar grade iron (III) sulphate was 47 mg total Fe l−1 (0·24 mg soluble Fe l−1 ). Lethal and sublethal exposure to both grades of iron resulted in accumulation on the gill, which appears to be the main target for iron toxicity. Greater iron accumulation occurred during exposure to commercial iron sulphate liquor. Physical clogging of gills and gill damage was seen during lethal and sublethal exposure to iron. Gill tissue analysis showed no evidence of iron uptake into gill tissues during lethal or sublethal exposure to iron. Iron did not accumulate in plasma of fish exposed to iron compared to controls. Respiratory disruption due to physical clogging of the gills is suggested as a possible mechanism for iron toxicity.
Journal of Fish Biology - Tập 55 Số 2 - Trang 301-315 - 1999
Disease resistance, stress response and effects of triploidy in growth hormone transgenic coho salmon Diploid and triploid coho salmon Oncorhynchus kisutch transgenic for growth hormone (GH) and control coho salmon were compared for differences in disease resistance and stress response. Resistance to the bacterial pathogen Vibrio anguillarum was not affected in transgenic fish relative to their non‐transgenic counterparts when they were infected at the fry stage, but was lower in transgenic fish when infected near smolting. Vaccination against vibriosis provided equal protection to both transgenic and non‐transgenic fish. Triploid fish showed a lower resistance to vibriosis than their diploid counterparts. Diploid transgenic fish and non‐transgenic fish appeared to show similar physiological and cellular stress responses to a heat shock. These studies provide information useful for both performance and ecological risk assessments of growth‐accelerated coho salmon.
Journal of Fish Biology - Tập 63 Số 3 - Trang 806-823 - 2003
Changes in some endocrinological and non‐specific immunological parameters during seawater exposure in the brown trout The influence of autumnal progressive and direct seawater transfers on ionic parameters, plasma growth hormone (GH) and thyroid hormones (TH) and also on the non–specific immune traits phagocytic activity, lysozyme and non–specific cytotoxicity were examined in 45–55 g brown trout (Salmo trutta ). In both experiments, the seawater transfer induced the same pattern of endogeneous modifications but they were more pronounced and more lasting after the direct seawater transfer than after the progressive one. In seawater–transferred trout, there was a significant transitory increase of the plasma osmolarity, chloride concentration, GH levels and a transient decrease of the TH. The phagocytic activity of the pronephric leucocytes and the lysozyme concentrations were significantly higher in seawater–transferred trout than in controls. Nevertheless, the non–specific cytotoxicity should not be modified after the seawater exposure. Moreover significant positive correlations were observed between plasma GH and chemiluminescence or lysozyme increases. These data support the hypothesis that GH is involved in the salmonids’ non–specific immune potential, especially by stimulating the macrophage functions.
Journal of Fish Biology - Tập 46 Số 6 - Trang 1065-1081 - 1995
Mitochondrial DNA and allozyme analysis of Atlantic salmon, <i>Salmo salar</i> L., in England and Wales Allozyme variation was examined in 429 Atlantic salmon, from seven sampling sites in England and Wales. Contingency tests for genetic homogeneity using three diagnostic loci revealed no significant differences among populations from the north‐east and north‐west of the U.K., but detected significant aspartate aminotransferase (AAT) differences between these samples and those from the R. Itchen in Hampshire (southern England). Mitochondrial DNA variation was analysed in 40 salmon from five spawning sites in the R. Itchen. Eight restriction endonucleases were used, of which three (AVAII, HAE III and HINFI) revealed polymorphisms. Six matriarchal lineages were discriminated. Two of the six mtDNA types observed were site‐specific. These results suggest a reasonable expectation of discriminating spawning aggregations of Atlantic salmon.
Journal of Fish Biology - Tập 35 Số sA - Trang 253-260 - 1989
The accumulation of 137‐caesium from fresh water by alevins and fry of Atlantic salmon and brown trout The accumulation of 137‐caesium from water by alevins and fry of Atlantic salmon and brown trout was studied, At ‘normal’ pH (∼7.4), input rates (kWF ) and equilibrium concentration factors (CFeq ) of 137‐caesium were four to five times greater in both species of alevins than those in the fry. Input rates and equilibrium concentration factors were consistently greater in brown trout than in Atlantic salmon. The input rate of 137‐caesium was most rapid in kidney, gill and gut of fry. The majority of the radiocaesium was, however, deposited in muscle tissue which had consistently the longest biological half‐life of 50–90 days. 137‐Caesium input was significantly reduced at low pH (∼5.0) but output rates (kFW ) were little affected. It is concluded that juvenile fish are more susceptible than adults to radiocaesium accumulation from freshwater but that food is the major source of 137‐caesium in freshwater fish. The behaviour of 137‐caesium is discussed with respect to potassium.
Journal of Fish Biology - Tập 43 Số 6 - Trang 877-888 - 1993
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