INDUCTION OF MATURATION AND SPERMIATION IN THE MALE
EUROPEAN EEL/ ASSESSMENT OF SPERM QUALITY THROUGHOUT TREATMENT
L. Pérez, J. F. Asturiano,
A. Tomás, S. Zegrari, R. Barrera,
F. J. Espinós, J. C. Navarro, M.
Jover-2000
Journal of Fish Biology, 57(6): 1488-1504
Abstract:
Weekly injections of human chorionic
gonadotropin (hCG; 1·5IU g-1W) induced spermiation in
87-100% farmed male European eels Anguilla anguilla
over a 10-week period, producing 3ml (100g)-1milt
volume, at 1·4×109spermatozoa ml-1sperm
mobility peaked in ninth week of treatment with 97% of
males with motile sperm. Gonadotropin-treated males showed
earlier but similar morphological changes to control
males. Whereas higher sperm density was obtained 6h
after hCG administration, higher percentage of motile
cells and longer sperm mobility were observed 24h after
the treatment indicating that this is the optimum time
to obtain good sperm after the hormonal induction.
Several monounsaturated fatty acids in sperm increased
significantly from week 5 to 9 of treatment
(when highest volume, density and mobility of milt
were recorded), whereas eicosapentaenoic acid (EPA),
docosahexaenoic acid (DHA) and total n-3 polyunsaturated
fatty acids (PUFAs) were significantly reduced. Fatty
acid levels returned to initial values after 13
weeks of treatment. These results are in agreement
with the reduction of n-3 PUFAs recently observed in
the ovary of female Japanese eel during artificial
maturation, and an attempt is made to suggest a
physiological explanation of its possible relation with
sperm quality.