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Density Dependent and Density Independent Regulation of Reproduction in the Gila Topminnow, Poeciliopsis Occidentalis (Baird and Girard)
Author(s) -
Schoenherr Allan A.
Publication year - 1977
Publication title -
ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.144
H-Index - 294
eISSN - 1939-9170
pISSN - 0012-9658
DOI - 10.2307/1935619
Subject(s) - reproduction , predation , population density , biology , ecology , photoperiodism , population , density dependence , zoology , demography , botany , sociology
Studies of the Gila topminnow, Poeciliopsis occidentalis, indicate that onset of reproduction, proportion of reproducing ♀ ♀, and numbers of embryos carried by ♀ ♀ are influenced by H 2 ) temperature, photoperiod, food, and predation. Water temperature and photoperiod act upon the fishes regardless of population density, whereas, nutrition influences and predation are proportionate to population density. Therefore, density dependent and density independent factors operate to regulate reproduction and neither is mutually exclusive.