Eradication of predatory fishes in shrimp farms by utilization of Thai tea seed     

Makoto Terazaki  Prapan Tharnbuppa  Yashima Nakayama 《Aquaculture (Amsterdam, Netherlands)》1980,19(3):235-242

The chief predatory fishes found in shrimp culture ponds in Thailand are Tilapia mossambica, Lates calcarifer, Scatophagus argus, Eluetheronema tetradactylum, Goviupterus chuno, Mystus sp., and other gobies. The eradication of predators, mostly fishes, is necessary for good management of any shrimp farm. Tea seed grown in northern Thailand has been used for this purpose. Quantitative analysis of crude saponin in the tea seed was conducted and some biological tests on the toxicity of crude saponin to fish were performed.The effective dosage of crude saponin for the eradication of predatory fishes was 1.1 ppm, but shrimp, crabs, copepoda, rotifers and brine shrimp (Crustacea) all survived this concentration. The lethal time for fishes increased in proportion to their body weight and the salinity of the pond. The toxicity of the saponin weakened with time.  相似文献