Living on the wedge: female control of paternity in a cooperatively polyandrous cichlid.
Theories suggest that, in cooperatively breeding species, female control over paternity and reproductive output may affect male reproductive skew and group stability. Female paternity control may come about through cryptic female choice or female reproductive behaviour, but experimental studies are scarce. Here, we show a new form of female paternity control in a cooperatively polyandrous cichlid fish (Julidochromis transcriptus), in which females prefer wedge-shaped nesting sites. Wedge-shaped sites allowed females to manipulate the siring success of the group member males by spawning the clutch at the spot where the large males were just able to enter and fertilize the outer part of the clutch. Small males fertilized the inner part of the clutch, protected from the large aggressive males, leading to low male reproductive skew. Small males provided more brood care than large males. Multiple paternity induced both males to provide brood care and reduced female brood care accordingly. This is, to our knowledge, the first documented case in a species with external fertilization showing female mating behaviour leading to multiple male paternity and increased male brood care as a result.
Kohda
Masanori
M
Animal Sociology, Department of Biology and Geosciences, Graduate School of Science, Osaka City University, Osaka 558-8585, Japan. maskohda@sci.osaka-cu.ac.jp
Heg
Dik
D
Makino
Yoshimi
Y
Takeyama
Tomohiro
T
Shibata
Jun-ya
JY
Watanabe
Katsutoshi
K
Munehara
Hiroyuki
H
Hori
Michio
M
Awata
Satoshi
S
D000704:Analysis of Variance; D000818:Animals; D049628:Body Size; D023681:Cichlids / Q000502:physiology*; D003163:Competitive Behavior / Q000502:physiology*; D005260:Female; D008297:Male; D009425:Nesting Behavior / Q000502:physiology*; D012726:Sexual Behavior, Animal / Q000502:physiology*; D013037:Spatial Behavior / Q000502:physiology*