Distribution of Metals in Tissues of the Common Carp (Cyprinus carpio L.)

The aim of the present study was to investigate the distribution of selected metals (As, Cd,Pb, Hg, Cr, Cu and Zn) in tissues of the common carp (Cyprinus carpio L.) grown in ponds. A total of 125 market-ready carp (aged 3 - 4 years, weight 2312 ± 583 g) from 10 fishponds in the Czech republic were analysed. The tissues analysed included muscle, liver, kidney, spleen, gills, ovaria and testes. Metal concentrations were determined by the AAS, mercury was determined using a cold-vapour AAS analyse (AMA 254). Results showed different affinities of metals to different tissues. The highest concentrations of As and Hg were in muscle tissue, Cu in the liver, and Cd and Zn in the kidneys, compared with levels in other tissues (p p p p < 0.01) were found in the ovaria compared with the testes. The study showed that meat and gonads of pond carp in the Czech republic are safe from the point of view of contamination with the metals investigated

The effect of pesticide based on diazinon for common carp (Cyprinus carpio L.)

The aim of the study was to assess the toxicity of pesticide based on organophosphorus for fish. The Basudin 600EW (active substance diazinon, 600 g/l) praparation was tested. The effect was assessed by acute toxicity tests, haematological indicies and biochemical blood plasma profiles

The Effect of Diazinon on Haematological Indices of Common Carp (Cyprinus carpio L.)

The goal was to assess an effect of diazinon [0,0-diethyl 0-(2-isopropyl-6-methylpyrimidin-4yl) phosphorothioate] on common carp (Cyprinus carpio L.). The effect was assessed based on results of acute toxicity tests and on a comparison of results of haematological examination of a control and an experimental group exposed to Basudin 600 EW pesticide preparation (active substance 600 g.l-1 of diazinon). The acute toxicity test lasting 96 h was performed semistatically on common carp juveniles. Examination of erythrocyte and leukocyte profile was performed on 15 control and 25 experimental specimens of one-to-two-year-old common carp after 96 h of exposure to Basudin 600 EW in concentration of 32.5 mg.l-1. The 96hLC50 value of Basudin 600 EW for common carp juveniles was 26.7 mg.l-1. The experimental group of one- to two-year-old common carp showed significantly lower values (p &lt; 0.01) of erythrocyte count (RBC), haemoglobin content (Hb) and haematocrit (PCV) compared to the control group. Values of MCV, MCH and MCHC were comparable in both groups during the study. In contrary, there was a significant decrease in leukocyte count (Leuko) (p &lt; 0.01), as well as in both the relative and absolute lymphocyte count (p &lt; 0.01) and a significant increase in both the relative and absolute count of developmental forms of neutrophile granulocytes: myelocytes (p &lt; 0.01) and metamyelocytes (p &lt; 0.05) in the experimental group

EFFECT OF CULTURE CONDITIONS ON REPRODUCTIVE TRAITS OF BROWN TROUT SALMO TRUTTA L.

Progeny from artificial propagation of wild brown trout (Salmo trutta L.) of the Blanice river, Czech Republic, were farmed to maturity and spawned at ages three, four and five during 2002-2004. Reproductive parameters and biological quality of eggs in this farmed population were compared to those of the original wild population. ANCOVA showed no differences between wild and farmed fish in weight of eggs per female, total fecundity, or relative fecundity in any year. Significantly higher egg diameter (4.57 mm, P = 0.001) and weight (69.3 mg, P = 0.0375) were found in the wild population in 2002 and conversely in 2004, the mean egg weight was higher in the farmed population (94.7 mg, P = 0.0021). Differences in egg diameter in this year (4.64 ± 0.06 and 4.82 ± 0.06 in wild and farmed trout, respectively) were close to the level of significance (P = 0.079). Mutual correlations between length or weight and studied reproductive traits were similar in both populations. Fertilization rate, duration of incubation period, egg losses during incubation and mortality of starving hatched fry were monitored in embryos and larvae of farmed population only (FxF), crosses between farmed females and wild males (FxW) and wild population only (WxW). Altogether 6.3%, 5.8% and 5.4% of eggs died during incubation period in FxF, FxW and WxW, respectively. There were also no significant differences in duration of incubation period and mortality of starving fry. It can be concluded that farming conditions did not significantly affect the reproductive parameters and quality of eggs in the first generation of farmed broodstock

EFFECT OF CULTURE CONDITIONS ON REPRODUCTIVE TRAITS OF BROWN TROUT SALMO TRUTTA L.

Progeny from artificial propagation of wild brown trout (Salmo trutta L.) of the Blanice river, Czech Republic, were farmed to maturity and spawned at ages three, four and five during 2002-2004. Reproductive parameters and biological quality of eggs in this farmed population were compared to those of the original wild population. ANCOVA showed no differences between wild and farmed fish in weight of eggs per female, total fecundity, or relative fecundity in any year. Significantly higher egg diameter (4.57 mm, P = 0.001) and weight (69.3 mg, P = 0.0375) were found in the wild population in 2002 and conversely in 2004, the mean egg weight was higher in the farmed population (94.7 mg, P = 0.0021). Differences in egg diameter in this year (4.64 ± 0.06 and 4.82 ± 0.06 in wild and farmed trout, respectively) were close to the level of significance (P = 0.079). Mutual correlations between length or weight and studied reproductive traits were similar in both populations. Fertilization rate, duration of incubation period, egg losses during incubation and mortality of starving hatched fry were monitored in embryos and larvae of farmed population only (FxF), crosses between farmed females and wild males (FxW) and wild population only (WxW). Altogether 6.3%, 5.8% and 5.4% of eggs died during incubation period in FxF, FxW and WxW, respectively. There were also no significant differences in duration of incubation period and mortality of starving fry. It can be concluded that farming conditions did not significantly affect the reproductive parameters and quality of eggs in the first generation of farmed broodstock

Recapture and condition of pond-reared, and hatchery-reared 1 + European grayling stocked in addition to wild conspecifics in a small river

The relative performance of European grayling Thymallus thymallus reared in a hatchery on commercial dry feed or in a pond with natural food and their wild conspecifics, was assessed through recapture of tagged fish 5 months after their release into the Blanice River, Czech Republic. One-year old pond and hatchery reared fish from a resident broodstock were marked using Visible Implant Elastomer tags and released into 3 sections of river in May 2006. Wild one-year-old grayling were also tagged in these sections on the same days. The ratio of hatchery reared, pond reared, and wild fish was 1:1:1 in all sections. The recapture rate (hatchery 14.9%, pond 22.1%, and wild 51.3%) and site fidelity (hatchery 7.8%, pond 13.0%, and wild 35.1%) were significantly different among groups. Wild fish had a higher probability of recapture upstream of their original section than did hatchery or pond reared fish. Pond rearing was superior to conventional hatchery rearing for subsequent stocking of 1 +  grayling in running water. Initially different mean condition factors were similar in all groups at recapture, suggesting adaptation of the artificially reared fish that remained in the river sections surveyed