多棘海盘车对四种贝类摄食率和选择性的初步研究

在水温为22～24℃,盐度29.6,溶解氧6.9 mg/L,pH 8.01的条件下,研究了多棘海盘车(Asterias amurensis)对4种贝类栉孔扇贝(Chlamys farreri)、贻贝(Mytilus edulis)、东方缝栖蛤(Hiatella orientalis)、菲律宾蛤仔(Ruditapes philippinarum)的摄食与食物选择性,以期了解多棘海盘车摄食生理生态学特性。结果表明:当只有一种贝类作为饵料时,多棘海盘车对不同贝类的摄食率差异极显著(P<0.01)。其中,对东方缝栖蛤的摄食率最大,为0.005 7～0.008 0 g干重/(h.只)(壳长为7～20 mm),其次是贻贝为0.003 5～0.004 9 g干重/(h.只)(壳长为10～21 mm),对栉孔扇贝的摄食率最小,为0.001 4～0.002 8 g干重/(h.只)(壳长为14～31 mm)。同时,多棘海盘车的摄食率还表现出一定的昼夜差异,夜间的摄食率大于白天,但差异并不显著(P>0.05)。当4种贝类同时作为饵料存在时,多棘海盘车对东方缝栖蛤的摄食率最大,为0.003 0 g干重/(h.只),其次是贻贝为0.001 7 g干重/(h.只),以摄食率评价摄食选择,多棘海盘车对于该4种贝类具有明显的选择性(P<0.05),其摄食选择性的顺序为:东方缝栖蛤,贻贝,菲律宾蛤仔,栉孔扇贝。

Feeding rate and food preference of Asterias amurensis on four species of bivalves

In order to study the feeding-physiological ecology of starfish(Asterias amurensis),the feeding rate and food preference to four species of bivalves were determined at temperature 22-24 ℃,salinity 29.6,dissolved oxygen 6.9 mg/L and pH 8.01.The results of feeding rate suggested a significant difference(P<0.01) when culture of the starfish with each bivalve,respectively.The starfish had the highest feeding rate on Hiatella orientalis at 0.005 7-0.008 0 gdw/(h·ind)(the shell length was 7-20 mm),followed by Mytilus edulis(0.003 5-0.004 9 gdw /(h·ind),the shell length was 10-21 mm) and the lowest feeding rate on Chlamys farreri(0.001 4-0.002 8 gdw /(h·ind),the shell length was 14-31 mm).At the same time,the feeding rate of starfish on the bivalves also showed a certain difference of day and night,exhibiting the higher feeding rate during the night than day,but the difference was not significant(P> 0.05).When cultured with four species of bivalves together,the starfish also showed the highest feeding rate on H.orientalis 0.003 0 gdw/(h·ind),followed by M.edulis 0.001 7 gdw /(h·ind) and less preference feeding on the C.farreri and R.philippinarum.The starfish had obvious selectivity(P<0.05) on four species of bivalves by the feeding rate,and the sequence ranked after the feeding selectivity was H.orientalis,M.edulis,R.philippinarum,C.farreri.