منابع مشابه
Maternal immune factors and the evolution of secondary sexual characters
Nicola Saino, Roberta Martinelli, Clotilde Biard, Diego Gil, Claire N. Spottiswoode, Diego Rubolini, Peter F. Surai, and Anders P. Møller Dipartimento di Biologia, Università degli Studi di Milano, via Celoria 26, I-20133 Milano, Italy, Laboratoire de Parasitologie Evolutive, CNRS UMR 7103, Université Pierre et Marie Curie, Bâtiment A, 7ème étage, 7 quai Saint Bernard, Case 237, F-75252 Paris C...
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Reproductive development and energy stores were characterized for sockeye salmon (Oncorhynchus nerka) maturing in the wild (Pick Creek, Bristol Bay, Alaska). Between freshwater entry and the start of spawning, ovaries increased in mass by 87.1% and secondary sexual characters increased in linear dimension by 13.0–47.4%. Between the start of spawning and death, secondary sexual characters decrea...
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According to sperm competition models, a male spawning in a disfavoured role should have spermatozoa with higher velocity but shorter longevity compared with a male spawning in a favoured role. Moreover, immunosuppressive androgens are needed to produce both secondary sexual characters and sperm cells. The ‘sperm protection’ hypothesis suggests that the immunosuppressive action of androgens has...
متن کاملSecondary sexual characters and sperm traits in coho salmon Oncorhynchus kisutch.
A study was undertaken to examine secondary sexual characters (spawning colouration and overall body size) in relation to sperm metrics in one alternative reproductive tactic of coho salmon Oncorhynchus kisutch: large hooknose males that spawn in dominance-based hierarchies. Males with less intense red spawning colouration had higher sperm velocities than males with darker red spawning colourat...
متن کاملSexual cannibalism and mate choice decisions in wolf spiders: influence of male size and secondary sexual characters
Sexual cannibalism may influence expression of elaborate male traits by either reinforcing or opposing sexual selection. Male Schizocosa ocreata (Hentz) wolf spiders (Lycosidae) have tufts of bristles on the first pair of legs that may function as a condition-indicating signal trait. We paired virgin and previously mated adult females with males under seminatural conditions (laboratory containe...
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ژورنال
عنوان ژورنال: Nature
سال: 1901
ISSN: 0028-0836,1476-4687
DOI: 10.1038/063231b0