Observations on reproduction techniques applicable to the European eel (Anguilla anguilla L.)
1998
Amin, E.M. (National Institute of Oceanography and Fisheries, Alexandria (Egypt))
Immature silver male eels Anguilla anguilla were injected weekly with a human chorionic gonadotropin hormone (HCG) at a concentration of about 1.5 IU per g BW. The injection increased the gonadosomatic index (GSI) from 0.03 to 9.0. All treated males spermiated after the 5th injection and milt of high quality was obtained: pH amounted to 8.0, spermatocrit values equal to 75.0 per cent, average sperm swimming speed was 6000 micron. Sperm required about five seconds to reach the opposite side of the ripe egg with average diameter of 1.2 mm. Sodium and calcium could be considered as having a direct stimulating effect on sperm motility, while the functional state potassium is essential to activation mechanism of sperm depending on the dose used. A good correlation seems to exist between experimental conditions, ovarian maturation and injection by a combination of (2 mg Carp Pituitary CP per 100 g BW) two times a week within 70 days. The absolute fecundity amounted to 1.48 x 10 to the power of 6. The ripe female and male eels were kept in the same tank, at a sea water temperature of 21-23 degrees C. And although spawning behaviour was observed, spawning did not occur. Twenty minutes after insemination, fertilized eggs formed a moderate perivitelline space.
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