The Study On Ecological Condition And Reproductive Biology Of Adult Perineresi Nuntia Savigny Under Artificial Culture Condition

Perineresi nuntia Savigny is benthonic animal. It devours the deposit and floating pellet feed with the proboscis turning inside out under the temperature of 16-32C. The adults can survive for one month embedded in humid substrate under 19-20C. The suitable (optimum) ecological factors were as follows: temperature 0-32(16-32) C, salinity 5.72-42.91(16.16-31.69), pH 7-9. Due to its strong ecological adaptability it can be an intensive culture species in the coastal zone of Shandong province.The sex gland can be developmented under 16-32C as long as it can feed and all body segments have germ cells . The heteromophosis will be formed when the adult is cultured under 18-32C and from this culture temperature the promotive effect of slow rising is more obvious than keeping high temperature. Lengthen light time can promote the formation of heteromophosis obviously. The planktonic rhythm of Perineresi nuntia Savigny is not obvious under the artificial control condition .The propagation of Perineresi nuntia Savigny can be realized by not only natural spawning but also artificial insemination and the fertility rate exceeds 90%. Under the artificial condition the heteromophosis average weight is about 0.4g and the average oviposition amounts are 13,000-18,000. The egg diameter is about 240 m. The eggs are sinkable and adhensive. The optimum hatching temperature is 18-25C and the salinity is 15-24. Under the temperature of 25 C the hatching time is 65h and the hatching rate is 92%.The newly-hatched larvae is nectochaete and larva with 4 segments will be benthonic gradually and then the adhesive substrate could be put in. At the stage of larvae the temperature should be controlled ranging from 24 to 28 C and the salinity from 15 to 42. Before the larva with 10 segements the suitable diet is microalgea and/or powder food and from then on is the pellet food.