几种微藻对方斑东风螺浮游幼虫生长和变态的影响

Effects of algae on the growth and metamorphosis of planktonic larvae Baylonia aerolato

本文报道了4种微藻不同浓度对方斑东风螺幼虫生长和变态的影响.结果表明,幼虫对4种微藻都能摄食,当投喂不同浓度的牟氏角毛藻、湛江叉鞭金藻时,摄食角毛藻（20×10^4cells/cm^3）生长最快达77.9μm/d、变态率52.5%;摄食金藻（20×10^4cells/cm^3）变态率最高达59.0%、生长速度70.4μm/d,随金藻浓度的上升,幼虫生长速度和变态率都上升.投喂不同浓度的青岛大扁藻时,最高变态率是24.4%（1×10^4cells/cm^3）,最快生长速度是59.3μm/d（7×10^4cells/cm^3）,随扁藻浓度的上升,幼虫的生长速度上升而变态率下降.摄食云微型藻幼虫生长缓慢,浮游期全部死亡.幼虫单独摄食角毛藻、金藻和扁藻,其首次出现变态个体的日龄分别是10、11、14d,而完成变态的日龄分别是22～23d、21～23d和26～28d.比较上述4种微藻,角毛藻和金藻是方斑东风螺幼虫的最适饵料,根据大水体人工育苗的具体条件,合适浓度应为角毛藻（5～10）×10^4cells/cm^3,金藻（10～15）×10^4cells/cm^3.而扁藻不宜单独投喂,作为辅助饵料较合适.

This paper reported effects of 4 microalgae and their concentrations on growth and metamor-phosis of planktonic larvae Baylonia aerolato. The results showed that the larvae were able to ingest these microalgae. When the larvae were fed with different concentrations of, Chaetoceros mueUeri, Dicratelia zhanjiangensis, the best growth rate for the larva was 77. 9 μn/d and the rate of larva metamorphosis was 52. 5% at the concentration of C. mueUeri （20 × 10^4cells/cm^3 ） ,the highest rate of metamorphosis of larvae was 59. 0% and the growth was 70. 4μn/d at the concentration of D. zhanjiangens/s （20 x 10^4cells/cm^3）. With increasing concentrations of the two microalgae, both growth and metamorphosis rate of larvae increased. When the larvae were fed with different concentrations of Platymonas qingdaoensis, the highest metamorphosis rate for larvae was 24. 4% at 1 × 10^4cells/cm^3 and the best growth rate was 59. 31μm/d at 7 × 10^4cells/cm^3. With increasing concentrations of Platymonas qingdaoensis, the growth rate of larvae increased but the metamorphosis rate decreased. Larvae grew slowly and all died when fed with microalgae Yunxiao during planktonic stage. When larvae were fed with single microalgae, C. muelleri , D. zhanjiangensis and P. qingdaoensis , the first metamorphosis appeared in 10d, lid and 14d, respectively, while all larvae completed their metamorphism was occurred in 22-23d, 21 -23d and 26 -28d, respectively. It showed that C. melleri and D. zhangjiangensis were the best food for the larvae of B. aerolato. According to the conditions of artificial rearing of larvae of B. aerolato in a large volume water, the suitable concentrations for C. muelleri were around （5 - 10）×10^4cells/cm^3, and （ 10 ～ 15） ×10^4cells/cm^3 for D. zhanjiangensis. It suggested that P. qingdaoensis is much suitable taken as supplemental food.