title: Intra-population variation in behavior modification by the acanthocephalan Acanthocephalus dirus: are differences mediated by host condition?
abstract: The acanthocephalan parasite Acanthocephalus dirus infects the freshwater isopod Caecidotea intermedius as an intermediate host before completing its life cycle in a fish. Male C. intermedius infected by A. dirus parasites are less likely to engage in mating behavior than uninfected males but there is a significant intra-population variation in the occurrence of this behavioral change. Previous studies on uninfected isopods have shown that glycogen content is a predictor of male mating behavior and we examined whether the intra-population variation in the mating behavior of infected male C. intermedius could be explained by this relationship. A field-based behavioral experiment was used to quantify intra-population variation in male mating behavior, which showed that 50% of infected males were responsive to females and 50% were not responsive. Biochemical analysis of responsive and non-responsive males revealed that glycogen content was a predictor of the mating behavior for uninfected males but was not a predictor of mating behavior for infected males. For infected males, parasite intensity was a predictor of mating behavior. Males that contained more A. dirus parasites were less likely to undergo modification of mating behavior. We propose that the intra-population variation in the mating behavior of infected C. intermedius identified in nature was not mediated by host condition.
authors.affiliation: Department of Biological Sciences, DePaul University, 2325 North Clifton Avenue, Chicago, IL, 60614, USA.
authors.forename: Sara C
authors.initials: SC
authors.lastname: Caddigan
authors.forename: Rima T
authors.initials: RT
authors.lastname: Barkauskas
authors.forename: Timothy C
authors.initials: TC
authors.lastname: Sparkes
mesh_terms: D000049:Acanthocephala / Q000502:physiology*; D000818:Animals; D005260:Female; D005399:Fishes; D005618:Fresh Water; D006003:Glycogen / Q000737:chemistry*; D006790:Host-Parasite Interactions; D033321:Isopoda / Q000469:parasitology*; D008018:Life Cycle Stages; D008297:Male; D011157:Population Dynamics; D012726:Sexual Behavior, Animal
chemical_list: D006003:Glycogen