There has been immense effort all over the world at trying to close the life cycle of the eel as a food fish. Looks like these guys are making head way.
;
;
;
| Aquaculture | |||||||||||||||||
| Volume 341, Number 5 (March 2012) | |||||||||||||||||
 |
Improvement in hatching rates in the Japanese eel Anguilla japonica by the control of rearing temperatures in the late stage of maturation in the female parents | ||||||||||||||||
| Authors: | Masayuki Yoshikawa | ||||||||||||||||
| Author Affiliations: |
|
||||||||||||||||
| Source: | Aquaculture, Volume 341, Number 5 (March 2012) | ||||||||||||||||
| Page Numbers: | 223 – 227 | ||||||||||||||||
| Available Full Text: |
|
||||||||||||||||
| Abstract: | In order to improve the hatching rate of eggs from artificially matured female eels, the environmental temperature during late stages of oocyte development was lowered from 20°C (control) to 18°C. Thus, female eels in which artificial maturation was induced at 20°C using chum salmon pituitary extract (SPE) were transferred to water at either 20 or 18°C at the beginning of the late stage of maturation. Biopsy by cannulation was carried out on the basis of an increase in body weight index (BWI; BWI=body weight×100/initial body weight). If the eel was judged to be nearing final maturation, a priming dose of SPE was administered, followed by a dose of maturation-inducing hormone (MIH). The average hatching rates of the eggs from the eels maintained at 20 and 18°C were 16.6% (n=10) and 45.9% (n=11), respectively. The hatching rates at 18°C were significantly higher than those at 20°C. At 20°C, the optimal timing of cannulation may often be missed due to both the rapid rate of oocyte development in the late stage and the unreliability of the BWI-based timing criterion. At 18°C, rapid development of maturing oocytes in the late stage was prevented, and the optimal ovulation induction period was prolonged. Accordingly, the likelihood for optimal timing of cannulation was increased, as reflected in high hatching rates of fertilised eggs. On the basis of these results, a temperature of 18°C in late stages of oocyte development is recommended to help in improving and stabilising the hatching rate. | ||||||||||||||||
| Citation: | Masayuki Yoshikawa . Improvement in hatching rates in the Japanese eel Anguilla japonicaby the control of rearing temperatures in the late stage of maturation in the female parents. Aquaculture, Volume 341, Number 5 (March 2012), pp. 223-227, ; | ||||||||||||||||
| URL: | http://ejournals.ebsco.com/direct.asp?ArticleID=4F2FA1EB06703CE2EDCE | ||||||||||||||||
