Testis size depends on social status and the presence of male helpers in the cooperatively breeding cichlid Julidochromis ornatus
نویسندگان
چکیده
Satoshi Awata, Dik Heg, Hiroyuki Munehara, and Masanori Kohda Laboratory of Animal Sociology, Department of Biology and Geosciences, Graduate School of Science, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi, Osaka 558-8585, Japan, Department of Behavioural Ecology, Zoological Institute, University of Bern, Wohlenstrasse 50a, CH-3032 Hinterkappelen, Switzerland, and Usujiri Fisheries Station, Field Science Center for Northern Biosphere, Hokkaido University, 152 Usujiri, Hakodate, Hokkaido 041-1613, Japan
منابع مشابه
The relationship between social status, behaviour, growth and steroids in male helpers and breeders of a cooperatively breeding cichlid.
We tested whether subordinate helper males of the Lake Tanganyika cooperatively breeding cichlid Neolamprologus pulcher show elevated excretion levels of the stress hormone cortisol and reduced levels of 11-ketotestosterone and testosterone when living in groups with a small breeder male, compared to similar helper males living in groups with a large breeder male, in a full-factorial repeated m...
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In social groups, subordinates may gain dominant breeding status either by inheriting the top position in their current group or by dispersing to join a new group. The pathway to breeder status is likely to vary between males and females as a result of sex differences in the costs of dispersal and inbreeding. We report results from a field study conducted to explore sex differences in the rates...
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* Freshwater Fisheries Research Division, National Research Institute of Fisheries Science, Fisheries Research Agency, Ueda, Japan Laboratory of Animal Sociology, Department of Biology and Geosciences, Graduate School of Science, Osaka City University, Osaka, Japan Center for Marine Environmental Studies, Ehime University, Matsuyama, Japan § Laboratory of Animal Ecology, Graduate School of Scie...
متن کاملHelpers in a cooperatively breeding cichlid stay and pay or disperse and breed, depending on ecological constraints.
The theory of family-group dynamics predicts that group structure, helping behaviour and social interactions among group members should vary with the opportunities of subordinates to breed independently. We investigated experimentally whether unrelated mature helpers in the cooperatively breeding cichlid Neolamprologus pulcher reduce costly social and cooperative behaviour and choose to dispers...
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We consider a cooperatively breeding group and find the optimal pattern of reproductive parasitism by a subordinate helper as a function of its body size, and hence the share of reproduction obtained by the subordinate. We develop the model for the social system of the cooperatively breeding cichlid fish Neolamprologus pulcher but the general framework is also applicable to other cooperative sy...
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