赤鼻棱鳀的摄食与生态转换效率

１９９８年９月利用对虾养殖土池中的赤鼻ＬｅｎｇＬｉ进行了摄食与生态转换率的观察研究。结果显示，赤鼻ＬｅｎｇＬｉ是典型的浮游动物食性鱼类，偏食大型桡足类和介形类，无明显摄食节律性；消化道日均食物含量１．２１９６ｇ（１００ｇ）＾－１．ｄ＾－１，排空率０．３１４１ｇ（１００ｇ）＾－１．ｈ＾－２，日摄食量１０．８１３５ｇ．（１００ｇ）＾－１．ｄ＾－１；食物转换效率３５．０８％，能量转换效率３９．３０％。渤海赤鼻ＬｅｎｇＬｉ的年饵料需求量约为８７０００ｔ。研究结果表明，较高的生态转换效率保证了赤鼻ＬｅｎｇＬｉ较高的生长率，因此较低的浮游动物生物量可支持这一鱼种较高的生产力，这被认为是渤浮游动物生物量大幅下降的同时赤鼻ＬｅｎｇＬｉ资源量却迅速增加的原因之一。

Consumption and ecological conversion efficiency of Thrissa kammalensis

Consumpt ion and ecological conversion efficiency of rednose anchovy, Thrissa kammalensis, was determined with samples of 38. 69- 64. 45mm in fork length and 0. 5179- 2. 1878g in body weight , caught in an earthen pond for shrimp rearing. Being a typical zooplanktonvore, rednose anchovy preferred to feed large copepods and o stracods without distinct feeding rhythm. Daily food content in its complete digestive tract was 1. 2196g#( 100g) - 1#d - 1 on average, and its daily food consumption was 10. 8135g#( 100g) - 1#d - 1 with an evacuation rate of 0. 3141g#( 100g) - 1#h - 1 . Food and energy conversion efficiency of this f ish was 35. 08% and 39. 30% respectively . In terms of its daily rat ion and abundance in the Bohai Sea, food requirement of redno se anchovy was deduced about 87 000 tones per year. Results indicate that high conversion eff iciency ensures the anchovy high growth rate, and lower zooplankton abundance may support its higher product ivity . That supplies a reason for that the stock of rednose anchovy increased rapidly while the biomass of zooplankton declined obviously in the Bohai Sea in recent years.