Effects of human chorionic gonadotropin (HCG), toad and Clarias pituitary hormogenates on spawning in the catfish: Clarias Lazera (C. and V.) and Clarias anguillaris (Linne)

Experiment on induced spawning of Clarias lazera and C. anguillaris using human chorionic gonadotropin (HCG) freshly prepared toad and Clarias pituitary hormogenates were carried out. Clarias pituitary hormogenates induced spawning in C. lazera and C. anguillaris at dosage levels of 0.27-0.46 mg/150 g body weight or 2 glands/fish of equivalent weights. HCG induced spawning in C. anguillaris at 500 i.u/500 g body weight but failed in C. lazera. Toad pituitary was not successful at even a higher dosage level of 0.60 mg/150 g body weight. The implications of these results are discussed. Spawning occurred in the HCG (and Clarias pituitary treated females in less than 12 hours after injection and subsequent examination of ovaries of the spawned fish showed incomplete spawning. Furthermore, fertilization occurred, following spawning in the piscine pituitary hormone treated male and female fish but failed in the HCG (treated pair. A mean fertilization rate of 50-90% was recorded. Possible explanations of these observations are advanced. The hatching time of 24-48 hours and a mean hatching rate of 75-90% were recorded. A high larval mortality of up to 95% was observed in the post yolk-sac stag after 8 days. The need for the development of appropriate larval food for Clarias species in culture practice is stressed

Incidence of human pathogenic bacteria in shrimp feeds - a study from India

The incidence of various human pathogenic bacteria in commercially available and home-made shrimp feeds used on some farms in India was analyzed. The Total Heterotrophic Bacteria in the commercial feed samples ranged between 103–105 cfu g-1 and those in the farm-made feeds between 106-107 cfu g-1. No bacteria of significance to human health were found to be associated with any of the commercial feed samples analyzed, while farm-made feeds analyzed during the study showed a high incidence of various human pathogens such as Vibrio parahaemolyticus, V. cholerae, Escherichia coli and Staphylococcus aureus. Possible modes of contamination in feeds and ways to prevent them are discussed.

The residue measurment of pesticide in water and biota of the Sorkhrood River in the south of the Caspian Sea

Pesticide residue is considered as a crucial factor in the fresh water ecosystem pollution of north Iran (Esp. Gillan and Mazandaran provinces). It is also regarded dangerous to the health of human being and animals. In this research , pesticide residue in 3 species of fish was gauged in stations of the Haraz river , the Sorkhrood river , and the Caspian sea. The sampeles were taken during 27 mounths (started in April 97 and ended to June 99). The maximum level of pesticide in water was found in July 98 for lindine at 12.4 ppb. The level of chlorinated pesticide residue recorded at 63 ppb in April 98. The level of. organophosphorus pesticides residue in water was at 1.75 ppb in Aug 97. The toxicity of the mentioned pesticide and bioaccomulation were taken into account in conducting this researched.