| reproductive biology of oreochromis niloticus (perciformes: cichlidae) at emiliano zapata dam, morelos, mexico. | the reproductive season of tilapia was studied by monthly samplings at emiliano zapata dam, morelos state, mexico. from february 1999 through february 2000 a sample of 50 fish was taken from the commercial catch (castnet, 6.5 cm of mesh size). the observed sex ratio was 1:1.29 (females:males) (chi(2)=10.26; p<0.05). the tilapia reached maturity at 151.3 mm (females) and 152.0 mm (males) of total length. rainy (august) and dry (february) seasons were determined as the breeding period. fecundity v ... | 2005 | 17354460 |
| reproductive aspects of oreochromis niloticus (perciformes: cichlidae) at coatetelco lake, morelos, mexico. | sex ratio, size at maturity, maturity stages, fecundity and egg diameter of oreochromis niloticus from coatetelco lake, morelos state, mexico, were studied from january to december 1993. sex ratio (male:female) was approximately 1:1.02. length at maturity was 117 mm (males) and 120 mm (females). the fecundity ranged between 104 and 709 eggs, with egg diameter from 1,000 to 3,000 microns. the gonadosomatic and hepatosomatic index indicate that the species breeds during summer and winter. | 2003 | 15162697 |