Folia Parasitologica 50[2] 129-134 (2003) | DOI: 10.14411/fp.2003.023

Activity levels and predator detection by amphipods infected with an acanthocephalan parasite, Pomphorhynchus laevis

Bahram S. Dezfuli¹, Barbara J. Maynard², Todd A. Wellnitz²

¹ Dipartimento di Biologia, Università di Ferrara, Via L. Borsari 46, Ferrara 44100, Italy

² Department of Biology, Colorado State University, Fort Collins, CO 80523, USA

The acanthocephalan parasite Pomphorhynchus laevis (Müller, 1776) uses freshwater amphipods as its intermediate host. In order to complete the life cycle, the infected amphipod must be consumed by a fish, where the acanthocephalan will mature and reproduce. Parasite transmission, and therefore fitness, could be enhanced if infected amphipods fail to detect or avoid predatory fish. We compared the activity levels of infected and non-infected amphipods, Echinogammarus stammeri (Karaman, 1931), in both the presence and absence of odours from its natural, definitive host, the fish Leuciscus cephalus (L.). Throughout the experiment, infected amphipods were more active than were non-infected individuals. The non-infected amphipods reduced their activity after the addition of fish odours, but the infected amphipods failed to show a significant decrease. The failure of infected amphipods to reduce activity levels in the presence of fish odour may reflect a parasite strategy to increase its chances of transmission by making its amphipod host more vulnerable to predation by fish.

Keywords: Acanthocephala, Pomphorhynchus laevis, parasitized crustacean, Echinogammarus stammeri, alteration of host activity

Received: May 14, 2002; Accepted: September 10, 2002; Published: June 1, 2003  Show citation