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Toxic effects of mercury on testicular activity in the freshwater teleost, Clarias batrachus (L.)
Author(s) -
Kirubagaran R.,
Joy K. P.
Publication year - 1992
Publication title -
journal of fish biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.672
H-Index - 115
eISSN - 1095-8649
pISSN - 0022-1112
DOI - 10.1111/j.1095-8649.1992.tb02659.x
Subject(s) - catfish , clarias , gonadosomatic index , biology , spermatogenesis , endocrinology , medicine , toxicity , mercury (programming language) , chloride , reproductive cycle , cholesterol , fish <actinopterygii> , chemistry , reproduction , fishery , population , ecology , demography , sociology , fecundity , computer science , programming language , organic chemistry
Catfish ( Clarias batrachus L.) were exposed to selected sublethal concentrations of mercuric chloride (HgCl 2 ; 0.05 mg l −1 ), methylmercuric chloride (CH 3 HgCl; 0.04 mg l −1 ) and emisan 6 (an organic mercurial fungicide; 0.5 mg l −1 ) for intervals of 45, 90 and 180 days from February to July (preparatory to spawning phase of the annual reproductive cycle). The gonadosomatic index showed a significant decrease after 90‐ and 180‐day exposure to the mercurials. Histologically, the seminiferous tubules were smaller in size and contained mostly spermatids in comparison to the control fish in which they were greatly distended and full of spermatozoa. The Leydig cells showed pycnotic changes in Hg‐treated fish after 90 and 180 days. In the Hg‐treated testes, total lipid content and 32 P uptake decreased significantly after 90 and 180 days. Levels of phospholipids and free cholesterol registered a significant reduction during all the durations. Esterified cholesterol level showed a significant decrease only in the 90‐day HgCl 2 and CH 3 HgCl groups, and in all 180‐day Hg groups, while the level of free fatty acid decreased significantly only in the 180‐day Hg groups. The observations suggest that impairment of testicular lipid metabolism by Hg is one of the possible factors that led to the inhibition of steroidogenesis and spermatogenesis.