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Gill Na+ (gill + na+)
Selected AbstractsSeasonal variation in osmoregulatory and metabolic parameters in earthen pond-cultured gilthead sea bream Sparus auratusAQUACULTURE RESEARCH, Issue 11 2009Luis Vargas-Chacoff Abstract Seasonal variations in osmoregulatory and metabolic parameters were assessed in juvenile gilthead sea bream (Sparus auratus) cultured in earthen ponds under a natural photoperiod and temperature. Specimens were sampled, and the plasma, gill, kidney and liver were collected during winter 2005 and 2006 (January), spring 2005 (April), summer 2005 (July) and autumn 2005 (October). Plasma osmoregulatory parameters showed higher values in summer, while metabolic parameters presented different patterns of variations. Gill Na+,K+ -ATPase activity decreased significantly in winter, while gill metabolite levels showed different patterns of variations among seasons. The enzymatic activities tested did not present a clear pattern of variation [(glutamate dehydrogenase (EC 1.4.1.2) (GDH) and hexokinase (EC 2.7.1.11) (HK)] or significant differences along seasons [glucose 6-phosphate dehydrogenase (EC 1.1.1.49)]. Kidney Na+,K+ -ATPase activity decreased during summer and autumn. Different patterns of variation were observed in kidney metabolite levels while all the enzymatic activities assessed [lactate dehydrogenase-oxidase (EC 1.1.1.27) (LDH-O), HK and GDH] presented the highest values during summer. In the liver, metabolite levels and enzymatic activities did not show significant variations or present clear patterns of variation along different seasons. These results indicated seasonal variations in the osmoregulatory and metabolic parameters of different organs (blood, gill, kidney and liver) in earthen pond-cultured gilthead sea bream (S. auratus), which could be mainly attributed to seasonal changes in temperature. [source] Genetic differences in physiology, growth hormone levels and migratory behaviour of Atlantic salmon smoltsJOURNAL OF FISH BIOLOGY, Issue 1 2001C. Nielsen Out of five strains of Atlantic salmon Salmo salar of 1+ years released upstream of a fyke net in the River Gudenaa in 1996, three, Lagan, Ätran and Corrib, migrated immediately, 50% of the recaptured fish reaching the net in 3,6 days. Burrishoole and Conon fish migrated with a 15,19 day delay. Smolt development in 1997 at the hatchery showed a spring surge in gill Na+, K+ -ATPase activity in all strains which was correlated with increased seawater tolerance. Differences in the timing of gill enzyme development matched the observed migration pattern well. Lagan, Ätran and Corrib strains reached high enzyme activity earlier than the Burrishoole and Conon strains, and strains with delayed enzyme development and migration showed a delayed regression of seawater tolerance compared with the early strains. Inter-strain differences in plasma growth hormone profiles could not be related to the observed patterns of Na+, K+ -ATPase and seawater tolerance development. The study gives evidence of genetic influence on the timing and intensity of smolting and subsequent migration in Atlantic salmon. [source] Sources of Phenotypic and Genetic Variation for Seawater Growth in Five North American Atlantic Salmon, Salmo salar, StocksJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 3 2010William R. Wolters In 2003, pedigreed families were obtained from two St. John's River sources, Penobscot River, Gaspè, and landlocked salmon stocks. Eyed eggs were disinfected upon arrival, and incubated in separate hatching jars. Fry were transferred prior to first feeding into individual 0.1-m3 tanks receiving 8 L/min of oxygen-saturated freshwater from a recirculating biological filtration system. At approximately 30 d after the initiation of feeding, fish densities were equalized to 250 fish/tank, fed 5% of the tank's total biomass in 3,4 daily feedings. When the fish were approximately 40 g, approximately 30 fish from each family were pit tagged and stocked communally into three replicated 10-m3 smolt tanks. Approximately 1 mo prior to stocking into sea cages for performance evaluations, evaluations of serum chloride levels and gill Na+, K+ -ATPase activity were measured on subsamples from all stocks in freshwater and following seawater challenge. Smolts were stocked into sea cages in June 2005, harvested in February 2007, and evaluated for carcass weight, sex, and stage of sexual maturity. Data were analyzed by the mixed model ANOVA to determine the random effects of sire and dam (sire), and the fixed effects of sex, salmon stock, ploidy level, and replicate smolt tank on carcass weight with smolt weight as a covariate. Sire and dam variance components were significantly different from zero, and the fixed effects of salmon stock, sex × stock interaction, and smolt weight at stocking were significant (P < 0.05). There were no significant differences among sexes, replicate smolt tank, or ploidy level for carcass weight. Overall, St. John's River fish had the fastest growth with a carcass weight >4.1 kg compared with the slowest growth in landlocked fish at 1.7 kg. Grilsing was also highest in St. John's River fish (ca. 4,6%) and lowest in Penobscot River fish (0%). The sire heritability for carcass weight calculated from the sire variance component using the mixed model ANOVA or MTDFREML was 0.26 ± 0.14. Data were used to calculate breeding values on captive sibling adult brood fish, and a line selected for carcass weight was spawned in the fall of 2007, and eggs from these fish were released to industry. [source] The effects of dietary NaCl supplement on hypo-osmoregulatory ability and sea water performance of Arctic charr (Salvelinus alpinus L.) smoltsAQUACULTURE RESEARCH, Issue 10 2000Magne Staurnes Groups of one-year-old smolts of Arctic charr (Salvelinus alpinus L.) reared under a simulated natural photoperiod were fed pelleted feed with a NaCl content of either 1.5% or 9.5% for 6 weeks before release in a river in northern Norway. There were no differences in growth before release between fish fed the two diets. Smolts fed the 9.5% NaCl diet had better hypo-osmoregulatory ability than those fed the 1.5% diet, and a level of gill Na+ -K+ -ATPase activity that was several times higher. One of the two groups that had been fed the 9.5% NaCl diet had both a significantly higher recapture rate and growth in sea than the two groups fed the 1.5% NaCl diet, whereas this was not true for the other 9.5% NaCl diet group. The results indicate that a NaCl-enriched diet could be used to ensure sufficient hypo-osmoregulatory ability of charr smolts that would otherwise have insufficient regulatory ability. [source] | ||||||||||