Estay, F., Diaz, N.F., Neira, R., Garcia, X.-1997
Progressive Fish Culturist, 59(1): 36-40
Abstract:
Data on reproductive traits from 1,229 mature 2 year old female coho salmon Oncorhynchus kisutch were collected during 2 years at four salmon farms in southern Chile. Spawning periods were similar in 1993 and 1994 (39 and 41 d, respectively). The spawning period of May-June, corresponded to the full reproductive period in the northern hemisphere. The mean weight of mature females (about 4 kg) was almost double the weight reported in the northern hemisphere for 2 year old maturing females. The pigmented eyed stage was reached approximately 270 accumulated temperature units (ATU days x degrees C above 0 degrees C) after fertilization. Averages for total fecundity (3,802 +/- 956 eggs/female, mean +/- SD; N = 1,188), relative fecundity (986 +/- 274 eggs/kg; N = 1,170), and egg diameter (7,11 +/- 0.51 mm; N = 1,185) were higher than corresponding values reported for coho salmon hatchery stocks in the northern hemisphere. Survival to the eyed egg stage averaged 74.3 +/- 24.2% (N = 1,147). Correlations of female body weight with total fecundity (r = 0.36; N = 1,170; P < 0.001), relative fecundity (r = 0.50; N = 1,170; P < 0.001), and egg diameter (r = 0.34; N = 1,167; P < 0.001) were lower but similar to those described for rainbow trout O. mykiss. Reproductive performance of Chilean coho salmon cultured in net pens was better than from systems in the northern hemisphere.
(Univ. Chile, Fac. Sci., Dept.Ecol. Sci., P.O.Box 653, Santiago, Chile)
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