The fecundity of tilapia species
1955
Lowe, Rosemary H.
Fecundity may be defined for the purposes of this paper as the number of young produced during the lifetime of individual; this number is determined by many factors; among which the more important are, the length of the breeding seasons, the frequency of spawning during a breeding season, the number eggs laid at a spawning, and the care taken ofthe eggs before and after hatching. Under, favorable and uniform conditions Tilapia may spawn at frequent intervals throughout their reproductive life, but where there are marked seasonal changes in climate they may have a brief and well defined annual breeding season. The number of spawnings year is determined by two variables duration of the breeding seasons, which appears to depend on climatic conditions,the frequency of spawning during the season, which may be characteristic of the species.
显示更多 [+] 显示较少 [-]