Male preference for colourful females affected by male size in a marine fish

• It is becoming increasingly clear that mate preferences are not static, but can vary as a function of ecological conditions and the state of the choosing individual. This applies not only to females, the sex that has usually been the subject in research on mate preferences, but also to males. Under certain conditions, males should be selective in their choice of breeding partner. In the two-spotted goby, Gobiusculus flavescens, a small marine fish, breeding females develop conspicuous yellow-orange bellies, which they actively display to males during courtship. We have recently shown that males prefer more colourful females as mates. In this study, we test if the size of a male affects his preference for colourful females. Using three-compartment mate-choice aquaria, we recorded the interest shown by a male in two females differing in coloration but similar in size. Large and small males were equally eager to court females, but only large males showed a greater interest in the more colourful females. We suggest that small males are unselective because they usually obtain few mating opportunities, as a result of being unsuccessful in mate attraction or male contest competition. This study provides the first demonstration that the size of a male affects his preference for female colour.

Subject headings

NATURVETENSKAP  -- Biologi -- Ekologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Ecology (hsv//eng)

NATURVETENSKAP  -- Biologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences (hsv//eng)

Keyword

female ornament

gobiusculus flavescens

male mate choice

sexual selection

two-spotted goby

male mate choice

gobiusculus-flavescens fabricius

potential reproductive rates

operational sex-ratios

male-male competition

predation risk

sand goby

pomatoschistus-minutus

gasterosteus-aculeatus

2-spotted goby

Publication and Content Type

ref (subject category)

art (subject category)