Implications for the maintenance of androdioecy in the freshwater shrimp, Eulimnadia texana Packard: Encounters between males and hermaphrodites are not random

Citation
Vl. Medland et al., Implications for the maintenance of androdioecy in the freshwater shrimp, Eulimnadia texana Packard: Encounters between males and hermaphrodites are not random, ETHOLOGY, 106(9), 2000, pp. 839-848
Citations number
25
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Animal Sciences","Neurosciences & Behavoir
Journal title
ETHOLOGY
ISSN journal
0179-1613 → ACNP
Volume
106
Issue
9
Year of publication
2000
Pages
839 - 848
Database
ISI
SICI code
0179-1613(200009)106:9<839:IFTMOA>2.0.ZU;2-Y
Abstract
Androdioecy is a mixed-mating system in which there are males and hermaphro dites but no pure females. Few species exhibit such a mating system. Eulimn adia texana is a branchiopod crustacean that has recently been identified a s an androdioecious species. This system is ideal for testing questions rel ated to the evolution of sexual reproduction. We are testing a model that p redicts androdioecy to be a stable mixed-mating system under certain condit ions. Specifically, we investigated whether encounters between males and he rmaphrodites are random or if either sex seeks out the other for mating. Fo cal male or hermaphrodite clam shrimp were presented with stimulus shrimp o f the other sex or kept alone. Swimming speed and time spent within differe nt areas of a test chamber were recorded. Males did not alter mean swimming speed or spend more time than expected by chance near partitioned hermaphr odites. Hermaphrodites, however, decreased mean swimming speed in the prese nce of males and also spent more time than expected by chance near partitio ned males, suggesting that hermaphrodites respond to male chemical and/or v isual stimuli. Modified swimming behaviour probably facilitates inter-sexua l contact, thereby increasing opportunities for outcrossing above that expe cted by random encounters.