TITLE

Food affects the potential reproductive rates of sand goby females but not of males

AUTHOR(S)
Kvarnemo, Charlotta
PUB. DATE
November 1997
SOURCE
Behavioral Ecology;1997, Vol. 8 Issue 6, p605
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
The interspawning interval of female sand gobies, Pomatoschistus minutus, a batch-spawning fish with paternal care, was significantly shorter when the fish were fed daily than when they were fed every fourth day. The incubation time of males was not affected by feeding, nor was the interbrood interval Males have an equal or higher potential reproductive rate than females. As females reproduce more slowly when food is scarce than when it is abundant, and males do not, the difference between the sexes in potential reproductive rate increases when there is food shortage. Because of this difference, both male bias in operational sex ratio and intensity in male-male competition for mates are predicted to increase as food availability decreases. Furthermore, a tradeoff between current and future reproduction is demonstrated to operate only when resources are limited, because the correlation between egg number of the first and second clutch was positive among high-food females but negative among low-food females. The number of eggs per female clutch did, however, not differ between treatments in first or second dutch. I conclude that operational sex ratio and sexual selection are expected to vary within and between sand goby populations in accordance with prey availability
ACCESSION #
80082567

 

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