Automated sperm morphology analysis in fishes: the effect of mercury on goldfish sperm

Abstract

This study is the first to examine the morphology of fish sperm using automated sperm morphology analysis (ASMA). The technique was applied to investigate the effect of an environmental pollutant, mercury, on the sperm morphology of goldfish Carassius auratus, and the effects on sperm morphology were compared with those on sperm motility. Goldfish sperm flagellar length was significantly shortened after instant exposure to 100 mg l−1 (368 µM) mercuric chloride, while curvilinear velocity (VCL) and the percentage of motile sperm were significantly decreased at mercuric chloride concentrations of 1 and 10 mg l−1 (3·68 and 36·8 µM), respectively. After 24 h exposure to 0·001 mg l−1 (0·0037 µM) mercuric chloride, flagellar length was significantly reduced in 38% of the spermatozoa. Following exposure to 0·1 mg l−1 (0·37 µM) mercuric chloride for 24 h, however, the majority of spermatozoa (98%), had significantly shortened flagella and increased sperm head length, width and area. Sperm motility was also significantly decreased at 0·1 mg l−1 (0·37 µM) mercuric chloride, probably due to the significantly reduced flagellar length at this concentration. This study shows that the morphological examination of fish sperm by ASMA provides, not only, an excellent tool for monitoring reproductive disruption caused by environmental pollution, but also has applications to other areas of fish reproductive biology, such as cryopreservation and aquaculture.

Motilidade espermática, fertilização dos ovócitos e eclosão dos ovos de Jundiá em água contaminada por cádmio

“…Van Look & Kime (2003) verificaram que a exposição dos espermatozoides de peixes em soluções crioprotetoras por 24 horas contendo crescentes níveis de cloreto de mercúrio causou injúrias nos espermatozoides e essas injúrias afetaram a motilidade dos espermatozoides, principalmente porque causaram diminuição do comprimento flagelar e aumento do tamanho da cabeça dos espermatozoides. Os autores atribuíram essas alterações ao fato de o mercúrio causar o rompimento dos microtubos que constituem os flagelos e da membrana plasmática que envolve a cabeça dos espermatozoides, promovendo assim um influxo de íons e soluções no interior da célula espermática.…”

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“…In similar work cad miu m (Cd) decreases the motility of carp spermatozoa in all tested concentrations, and that lethal effect was calculated 500 pp m by CASA Investigated the effects of Hg on sperms of goldfish (Carassius auratus) and discussed parameters of spermatozoa motility in terms of VCL value and spermatozoa morphology. According to the study, they found that concentrations of 1-10 mg/l mercury chloride (HgCl 2 ) significantly reduced VCL value of sperms and 100 mg/ l of HgCl 2 shortened the flagellu m length of spermatozoa (Van Look & Kime, 2003).…”

Assessing reproductive and endocrine parameters in male largescale suckers (Catostomus macrocheilus) along a contaminant gradient in the lower Columbia River, USA

“…For example, automated sperm morphology analysis detected the altered morphologies of goldfish (Carassius auratus) sperm after cell exposure to mercuric chloride (Van Look and Kime, 2003). Likewise, the CASA results of cadmium-exposed spermatozoa of African catfish (Clarias gariepinus) showed that progressive motility was subsequently reduced (Kime, 1996).…”