文蛤对四种单胞藻的表观消化状况及同化率  

Apparent digestion and absorption efficiency of four kinds of microalgae by hard clam Meretrix meretrix(Rumphius)

作　　者：冉福[1] 沈和定[1] 吕凛[1] 曹灏[1] 

机构地区：[1]上海水产大学农业部水产种质资源与养殖生态重点开放实验室,上海200090

出　　处：《上海水产大学学报》2007年第6期602-607,共6页Journal of Shanghai Fisheries University

基　　金：上海市教委发展基金项目(科03-125);上海市重点学科建设项目(Y1101)

摘　　要：水温22℃下，显微观察了文蛤对塔玛亚历山大藻及海水小球藻，等鞭金藻和青岛大扁藻的表观消化状况，以灰化法测定了文蛤对四种单胞藻的同化率。结果表明，低浓度时文蛤对四种藻类的表观消化状况优于高浓度组；文蛤对海水小球藻、等鞭金藻和青岛大扁藻的同化率随着藻类浓度的升高而降低，其同化率变化范围分别为87．9％～67．4％、83．4％～58．7％和67．5％～37．9％。当塔玛亚历山大藻浓度低于5．0×10^3cell／mL时，文蛤不会产生假粪，该藻能够被文蛤摄食。藻浓度在1．0×10^3cell／mL到3.0×10^3cell／mL时，文蛤对该藻的同化率从81．8％降至52．3％，4．0×10^3cell／mL组的同化率升高至67.6％，藻浓度升高至5．0×10^3cell／mL时同化率又降至52．4％，塔玛亚历山大藻3．0×10^3cell／mL浓度组是一个分界点，同化率最低，大于这一浓度时，同化率又呈上升趋势。The absorption efficiency （ AE ） of hard clam [ Meretrix meretrix （ Rumphius ） ] on Alexandrium tamarense and other three kinds of microalgae （marine Chlorella sp., Isochrysis galbana, Platymonas helgolandica ） was determined through the proportion of ash weight method, meanwhile, the apparent digestion of microalgae was observed with photomicrography, under water temperature 22 ℃. The results showed that the apparent digestion in lower density was better than that of higher density. The AE was correlated negatively with the concentration of algae except A. tamarense. When pseudofeces were not produced, the range of AE on marine Chlorella sp. , Isochrysis galbana, Platymonas halgolandica were 87.9% - 67.4% ,83.4% - 58.7% and 67.5% -37.9%. The clams didn＇t produce pseudofeces at the density of A. tamarense below 5 000 cell/mL. Furthermore, the AE of hard clam ranged from 81.8 % to 51.3 % in a concentration of Alexandrium tamarense from 1. 0 ×10^3 cell/mL to 3.0 ×10^3 cell/mL. The AE in the concentration of 4.0 ×10^3 cell/mL increased to 67.6%. Then it decreased to 52.4%, when the concentration became 5.0 ×10^3 cell/mL. It was considered that the concentration of 3.0 ×10^3 cell/mL was a watershed, over which the filter feeding activity of hard clamwill be greatly disturbed as the ingestion rate in the concentration of 4.0 ×10^3 cell/mL and 5.0 ×10^3 cell/mL decreased suddenly, while the absorption efficiency increased simultaneously.

关 键 词：文蛤 塔玛亚历山大藻 表观消化状况 同化率 

分 类 号：S968.3[农业科学—水产养殖]