In situ studies on physiological and biochemical responses of four fishes with different trophic levels to toxic cyanobacterial blooms in a large Chinese lake.
Physiological and biochemical responses of four fishes with different trophic levels to toxic cyanobacterial blooms were studied in a large net cage in Meiliang Bay, a hypereutrophic region of Lake Taihu. We sampled four fishes: the phytoplanktivorous Hypophthalmichthys molitrix and Aristichthys nobilis, the omnivorous Carassius auratus, and the carnivorous Culter ilishaeformis. Alterations of the antioxidant (GSH) and the major antioxidant enzymes (CAT, SOD, GPx, GST) in livers were monitored monthly, and the ultrastructures of livers were compared between the bloom and post-bloom periods. During the cyanobacterial blooms, the phytoplanktivorous fishes displayed only slight ultrastructural changes in liver, while the carnivorous fish presented the most serious injury as swollen endomembrane system and morphologically altered nuclei in hepatocytes. Biochemically, the phytoplanktivorous fishes possessed higher basal GSH concentrations and better correlations between the major antioxidant enzymes in liver, which might be responsible for their powerful resistance to MCs. This article provided physiological and toxicological evidences for the possible succession of fish communities following occurrence of toxic cyanobacterial blooms and also for the applicability of using phytoplanktivorous fish to counteract toxic cyanobacterial blooms in natural waters.
Qiu
Tong
T
Donghu Experimental Station of Lake Ecosystems, State Key Laboratory for Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072, PR China.
Xie
Ping
P
Ke
Zhixin
Z
Li
Li
L
Guo
Longgen
L
D000818:Animals; D001427:Bacterial Toxins / Q000633:toxicity*; D002681:China; D000458:Cyanobacteria / Q000378:metabolism*; D017753:Ecosystem; D004784:Environmental Monitoring; D005247:Feeding Behavior; D005399:Fishes / Q000378:metabolism*; D020387:Food Chain; D005618:Fresh Water; D012621:Seasons; D013997:Time Factors
D001427:Bacterial Toxins