Chronic effects of suspended solids on gill structure, osmoregulation, growth, and triiodothyronine in juvenile green grouper Epinephelus coioides
Chronic effects of suspended solids on gill structure, osmoregulation, growth, and triiodothyronine in juvenile green grouper Epinephelus coioides
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DOI：
10.3354/meps266255
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发表时间：
2004-01-01
影响因子：
2.5
通讯作者：
Tang, JYM
中科院分区：
文献类型：
--
作者：
Au, DWT;Pollino, CA;Tang, JYM
尽管悬浮固体是监管过程中的一个重要水质参数，但人们对鱼类，特别是海洋物种长期接触高浓度悬浮固体的风险知之甚少。在这项研究中，绿色石斑鱼斜带石斑鱼，一个重要的海水养殖品种，具有广泛的地理分布，暴露于不同浓度（0，50，100，200，1000和2000毫克l（-1））的悬浮固体6周。结果表明，在环境实际浓度下，接触不会致死，并且没有观察到食物摄入、生长和RNA：DNA比例的变化。然而，鳃结构的损害，包括上皮提升，增生的支柱系统，和上皮体积的减少，是显而易见的，并与悬浮固体浓度暴露密切相关。尽管观察到血清渗透压和红细胞压积值没有变化，Na+，K+-ATP酶活性和鳃板的氯细胞发生了改变，表明鱼正在经历压力调节。游离三碘甲状腺原氨酸（T3）水平降低。血清中的悬浮物进一步证实，鱼类正在经历悬浮固体暴露的生理应激。总体结果表明，长时间暴露可能导致亚致死压力和损害鱼类健康，即使我们提供的高悬浮固体浓度已报告在沿海环境中对绿色石斑鱼不致命。
Despite suspended solids being an important water-quality parameter in the regulatory process, very little is known about the risks of prolonged exposure to high concentrations of suspended solids in fish, especially marine species. In this study, the green grouper Epinephelus coioides, an important mariculture species with a wide geographic distribution, was exposed to various concentrations (0, 50, 100, 200, 1000 and 2000 mg l(-1)) of suspended solids for 6 wk. The results showed that exposure was not lethal at environmentally realistic concentrations, and no changes in food intake, growth and RNA:DNA ratio were observed. However, damages to gill structure, including epithelium lifting, hyperplasia in the pillar system, and reduction of epithelial volume, were clearly evident, and strongly correlated with suspended solid concentration exposure. Despite the observation that serum osmolarity and haematocrit values did not change, Na+, K+-ATPase activities and chloride cells of the gill lamellae were altered, indicating that fish were experiencing osmoregulatory stress. Reduction in levels of free triiodothyronine (T3). in serum further confirmed that fish were experiencing physiological stress with suspended solids exposure. The overall results suggested that prolonged exposures can cause sub-lethal stress and compromise fish health, even though the high suspended solids we delivered were in concentrations that have been reported in coastal environments as not lethal to green grouper.