食物类型和浓度对双齿许水蚤摄食的影响

在不同饵料条件下,对双齿许水蚤(Schmackeria dubin)的清滤率(mL.只-1.h-1)、滤食率(细胞.只-1.h-1)和摄食率(mg.只-1.h-1)进行了测定。结果表明:以湛江等鞭金藻(Isochrysis zhanjiangensis)为饵料,其浓度为15×104～120×104 mL-1时,双齿许水蚤的摄食率达到较大;分别饲以同生物量的牟氏角毛藻(Chaetoceros müelleri)、亚心形扁藻(Platymonas subcordiformis)、湛江等鞭金藻、小球藻(Chlorella sp.)时,饵料为角毛藻和扁藻时双齿许水蚤的摄食率达到较大;饲以同生物量的牟氏角毛藻、亚心形扁藻、湛江等鞭金藻、小球藻、颤藻(Oscillatoria sp.)、小环藻(Cyclotella sp.)六种藻的混合饵料时,双齿许水蚤对湛江等鞭金藻的摄食率和选食率均为最大,分别为0.0458 mg.只-1.h-1和17.1%。可见,饵料浓度、饵料种类、混合饵料对双齿许水蚤的清滤率和摄食率均有显著影响(P<0.05)。

Effect of Type and Density of Feed on Ingestion Characteristics of Schmackeria dubin

A test was carried out on the filtering rate(F,mL.ind-1.h-1),the grazing rate(G,cells.ind-1.h-1) and the ingestion rate(I,mg.ind-1.h-1) of Schmackeria dubin under different feed conditions.The result showed that when the feed was Isochrysis zhanjiangensis and the density of feed was 15×104~120×104 cells/mL,the ingestion rate was relatively high.When they were fed respectively with the same quantity of Chaetoceros müelleri,Platymonas subcordiformis,Isochrysis zhanjiangensis,and Chlorella sp.respectively,the ingestion rates were relatively high for Chaetoceros müelleri and Platymonas subcordiformis.When they were fed with the same quantity of mixed feed of Chaetoceros müelleri,Platymonas subcordiformis,Isochrysis zhanjiangensis,Chlorella sp.,Oscillatoria sp and Cyclotella sp.,the ingestion rate and chosen rate of Isochrysis zhanjiangensis were maximum at 0.0458 mg.ind-1.h-1 and 17.1% respectively.It is obvious that the density of feed,type of feed and mixed feed had remarkable effect on F,G and I of Schmackeria dubin.