不同水体营养状态对鳌和鱇鱇白鱼生长性能的影响

EFFECTS OF WATER TROPHIC STATUS ON GROWTH PERFORMANCES OF HEMICULTER LEUCISCULUS AND ANABARILIUS GRAHAMI

  • 摘要: 鳌和鱇鱇白鱼分别是抚仙湖的外来鱼类和土著鱼类。本实验比较研究了水体营养状态对二者生长性能的影响。实验鱼养殖在低、中、高三种营养状态的水体中。其中低营养状态水体组又是每一种鱼中、高营养水体组的对照。水体营养状态对鳌和鱇鱇白鱼摄食率、生长速度、饵料转化效率、蛋白贮积率没有显著影响。不同营养状态水体组实验鱼的体蛋白、脂肪、灰分和能量含量没有显著差异。富营养化对两种鱼生长性能的影响是不同的。特定生长率、饵料转化效率、蛋白贮积率和能量贮积率的种间差异值均随着水体营养状态的提高而加大。与对照组相比,较高营养状态水体中鳌的摄食率、特定生长率、饵料转化效率、蛋白贮积率和能量贮积率的增加率低于鱇鱇白鱼,或者降低率高于鱇鱇白鱼。实验结果说明,高营养状态对生长性能的负面影响较大;对于湖泊水体的富营养化,外来鱼类在生长性能方面不一定比土著鱼类具有优势。

     

    Abstract: Eutrophication and invasion do seem often to go hand in hand.Experimental evidence to support the ability of eutroph-ication to facilitate either the incidence, speed, or impact of non-indigenous species invasion is conspicuously lacking.With the increase of water trophic status from oligotrophic to mesotrphic, great changes happened in the fish composit ion of Fuxian Lake located in Yunnan Plateau, China, at present. A lot of exotic fishes were introduced into Fuxian Lake and spread quickly, and the populations of many native fishes declined which even become extinct. Effects of water trophic status on growth, feeding utilization, body composition of Hemiculter leucisculus (exotic fish for Fuxian Lake) and Anabarilius grahami (native fish for Fuxian Lake) were studied in this experiment,with an attempt to compare their adaptive ability to eutrophication in the aspect of growth performances. Fishes were reared at the water temperature from 17 e to 20 e in three types of water (LTS, the low-trophic-status water;MTS, the moderate-trophic-status water; and HTS, the high-trophic-status water). The group reared in LTS also served as the control of the groups reared in MTS and HTS for each species. The experiment lasted for 40 days. Feeding rate (FR), specific growth rate (SGR), feed conversion efficiency (FCE) and protein retention efficiency (PRE) were insignificantly affected by water trophic status for both H. leucisculus and A. grahami. There were no significant differences in body protein, lipid, ash and energy contents among the groups reared in three waters with different trophic status for two experimental fishes1However, energy retention efficiencies (ERE) of H. leucisculus reared in HTS was significantly lower than those reared in LTS, and EREs of A. grahami reared in MTS and HTS were significantly higher than that reared in LTS; Water content of A. grahami reared in MTS was significantly lower than those reared in LTS and HTS. Though effects of water trophic status on the growth performances of each fish were not evident,markedly differences were showed between H. leucisculus and A. grahami in the growth response to the increase of water trophic status. SGR of A. grahami was slightly higher than H. leucisculus. FCE and PRE of A. grahami were both higher than those of H. leucisculus, but the differences were significant only in MTS and HTS. ERE of A. grahami was signif-icantly higher than that of H. leucisculus. Interspecific differences in SGR, FCE, PRE and ERE all increased with the enhancement of water trophic status. The percentages increased in FR, SGR, FCE, PRE and ERE over control of H. leucisculus reared in MTS and HTS which were lower than those of A. grahami reared in the same type of water. Those differences between H. leucisculus and A. grahami in the effects of water trophic status on growth performances indicate that high trophic status is more unfavorable to the growth of H. leucisculus than that of A. grahami. The results speculated that the exotic fish might not show higher adaptive ability to eutrophication than the nat ive fish in growth performances.

     

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