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Homosexual rape and sexual selection in acanthocephalan worms
Science (New York, N.Y.)
|July 1, 1977
Summary
Acanthocephalan males use cement glands to seal females after mating, preventing further insemination. This cement gland evolution in acanthocephalans is interpreted as a result of sexual selection and parental investment.
Area of Science:
- Parasitology
- Evolutionary Biology
- Behavioral Ecology
Background:
- Acanthocephalan males possess cement glands linked to the vas deferens.
- These glands secrete a substance that forms a copulatory plug, sealing the female's vagina post-mating.
- This plug prevents subsequent insemination by other males.
Purpose of the Study:
- To investigate the function and evolutionary implications of cement glands in acanthocephalans.
- To understand the role of cement glands in both heterosexual and homosexual interactions.
- To interpret the evolution of cement glands and associated sexual behaviors within a parental investment framework.
Main Methods:
- Observational studies of acanthocephalan reproductive behavior.
- Analysis of secretions transferred during copulation and homosexual interactions.
- Interpretation of findings within the context of sexual selection theory.
Main Results:
- Cement gland secretions are transferred to females during copulation, forming a plug.
- In homosexual interactions, cement is transferred to males, sealing their genital region.
- This sealing effectively removes males from the reproductive population.
- Sperm transfer occurs during heterosexual copulation, but only cement is transferred during homosexual interactions.
Conclusions:
- The cement gland and its use in acanthocephalans are likely driven by sexual selection.
- The observed behaviors align with predictions from parental investment models.
- Cement gland secretions play a critical role in controlling fertilization and reproductive success in acanthocephalans.
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