Increase of milt production by hormonal treatment in the pejerrey fish Odontesthes bonariensis.

MIRANDA, LEANDRO ANDRES; CAROLINA CASSARÁ, MARIA; GUSTAVO SOMOZA,

AQUACULTURE RESEARCH

Blackwell

Lugar: Oxford; Año: 2005 vol. 36 p. 1473 - 1479

1355-557X

In spite of interest in the cultivation of the pejerrey fish Odontesthes bonariensis (Cuvier & Valenciennes 1835), there are few studies on subjects required to advance this activity. One of the problems is the synchronization of female and male maturation to provide eggs and sperm for larval production. The low volume of expressible milt, either in wild or culture fish, is a major problem. The aim of this work was to study the effectiveness of the administration of different hormones on sperm production in pejerrey. Milt production was enhanced by the injection of human chorionic gonadotropin (16.7 fold increase, 625 IU kg-1), carp pituitary extracts (13.5 fold increase, 30 mg kg-1), salmon pituitary extracts (12.8 fold increase, 30 mg kg-1), salmon type  gonadotropin-releasing hormone analogue (16.7 fold increase, 10 ìg kg-1) and mammalian type gonadotropin-releasing hormone analogue (10.8 fold increase, 20 ìg kg-1). Sperm concentration, motility, and the fertilization rate were not statistically different compared to control groups. It was also demonstrated that sperm could be obtain off-season. Taken together, human chorionic gonadotropin is recommended to stimulate pejerrey spermiation because it is effective in low doses, inexpensive and widely available.