Freezing of rainbow trout, Oncorhynchus mykiss, semen in nitrogen vapor

Abstract

This experiment was carried out at Estação Experimental de Salmonicultura de Campos do Jordão, São Paulo, Brazil (22° 45' S and 45° 30' W), in order to verify he effect of chilled diluted, frozen and thawed sperm, by rapid and slow methods on fertility of the rainbow trout, Oncorhynchus mykiss. The fertility averages were: chilled diluted milt = 86.8%; frozen milt/rapid thawing = 36.18%; frozen milt/slow thawing = 31.86%; fresh milt (control) = 93.68%. The conclusion from the data analysis were: 1) there was no significant difference (P<0.01) between the fertility of fresh milt and diluted chilled milt; 2) the rapid and slow thawing did not interfere in fecundity power of the spermatozoa.