Infection pattern of two simpatric acanthocephalan species in Hyalella patagonica (Amphipoda: Hyalellidae) from Lake Mascardi (Argentina).

RAUQUE, C.; SEMENAS, L.

PARASITOLOGY RESEARCH

Springer

Lugar: Düsseldorf ; Año: 2007 vol. 100 p. 1271 - 1276

0932-0113

Abstract The aim of the present study was to describe the infection pattern of the acanthocephalans Acanthocephalus tumescens and Corynosoma sp. co-occurring in the intermediate host the amphipod Hyalella patagonica. Samples were collected monthly from June 2002 to May 2004 from Lake Mascardi. Amphipods were measured, and classified by the developmental stages. Single and double infections of larval acanthocephalans were recorded and prevalence and mean intensity calculated. An annual life cycle of H. patagonica could be inferred with recruitment of juveniles from spring to autumn. Males and females were found all year round but females were significantly more abundant. Single infections were mainly found in smaller juvenile amphipods during winter for A. tumescens and in intermediate and large male amphipods during spring and summer for Corynosoma sp. Double infections showed low values and were mainly found in intermediate sized amphipods during spring. A segregation of the infection by season, and size and developmental stages of the host was recorded and would tend to avoid competition considering these two acanthocephalan species have different definitive hosts, fishes for A. tumescens and aquatic birds for Corynosoma sp.