1. Evolution of sperm morphology in anurans: insights into the roles of mating system and spawning location
- Author
-
Robert Jehle, Yu Zeng, Wen Bo Liao, and Shang Ling Lou
- Subjects
Male ,endocrine system ,Spawning location ,media_common.quotation_subject ,Zoology ,Sperm morphology ,Biology ,Competition (biology) ,Phylogenetics ,Testes size ,Testis ,Animals ,Mating system ,Sperm competition ,Ecology, Evolution, Behavior and Systematics ,reproductive and urinary physiology ,media_common ,urogenital system ,Reproduction ,Sperm ,Biological Evolution ,Spermatozoa ,Anurans ,Female sperm storage ,Sexual selection ,Female ,Anura ,Research Article - Abstract
Background: The degree of postcopulatory sexual selection, comprising variable degrees of sperm competition and cryptic female choice, is an important evolutionary\ud force to influence sperm form and function. Here we investigated the effects of\ud mating system and spawning location on the evolution of sperm morphology in 67\ud species of Chinese anurans. We also examined how relative testes mass as an\ud indicator of the level of sperm competition affected variation in sperm morphology\ud across a subset of 29 species.\ud Results: We found a significant association of mating system and spawning location\ud with sperm morphology. However, when removing the effects of body mass or\ud absolute testes mass for species for which such data were available, this effect became\ud non-significant. Consistent with predictions from sperm competition theory, we found\ud a positive correlation between sperm morphology and relative testes mass after taking\ud phylogeny into account.\ud Conclusions: Our findings suggest that sexual selection in Chinese anurans favors\ud longer sperm when the level of sperm competition is high. Pre-copulatory male-male\ud competition and spawning location, on the other hand, do not affect the evolution of\ud sperm morphology after taking body mass and absolute testes mass into account.
- Published
- 2013