Infection pattern of two sympatric acanthocephalan species in the amphipod Hyalella patagonica (Amphipoda: Hyalellidae) from Lake Mascardi (Patagonia, Argentina)

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 developmental stages. Single and double infections of larval acanthocephalans were recorded and prevalence and mean intensity were 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, 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.

Effects of two acanthocephalan species on the reproduction of Hyalella patagonica (Amphipoda, Hyalellidae) in an Andean Patagonian Lake (Argentina)

“…In order to avoid intra-and inter-specific interference effects, doubly infected crustaceans were not used. Considering that in Lake Mascardi prevalence of infection with the two acanthocephalan species is dependent of length of amphipods (Rauque and Semenas, 2007), in order to have similarly sized groupings, only unpaired amphipods in the same length range of paired ones were used (5.1-12.5 mm total length). Prevalences of A. tumescens and Corynosoma sp.…”

“…In Andean Patagonian Lakes, Rauque and Semenas (2007) stated that three acanthocephalan species, Acanthocephalus tumescens, Pomphorhynchus patagonicus and Corynosoma sp., use the amphipod Hyalella patagonica as an intermediate host. These authors also found segregation of the infection by season, size, and developmental stages (acanthellae and cystacanths) in the cases of sympatric infection of A. tumescens and Corynosoma sp.…”

The natural history of Echinorhynchus bothniensis Zdzitowiecki and Valtonen, 1987 (Acanthocephala) in a high Arctic lake

“…We also found higher prevalence in larger mysids. An increase in infection with intermediate host size has been observed in other acanthocephalans (Liat and Pike 1980, Wilson and Hubschman 1985, Lagrue et al 2007, Oliva et al 2008, La Sala et al 2012, although peak abundances in medium-sized hosts is perhaps the more common pattern (Hine and Kennedy 1974, Muzzall 1978, 1982, Camp and Huizinga 1980, Brattey 1986, Brown and Pascoe 1989, Lagrue et al 2007, Outreman et al 2007, Rauque and Semenas 2007. A number of processes could result in higher prevalence in bigger mysids.…”

Interactions among four parasite species in an amphipod population from Patagonia

“…In Patagonia, previous studies on the amphipod Hyalella patagonica have focused on population dynamics, in terms of the deleterious effects of infection by two acanthocephalan species, Acanthocephalus tumescens and Pseudocorynosoma sp., and the interactions between these acanthocephalan species (Rauque & Semenas, 2007, 2009, 2011). In Lake Mascardi, a large and deep oligotrophic lake, these two acanthocephalans are sympatric in H. patagonica , although segregation of infection in time and space occurs to avoid competition, i.e.…”

“…A. tumescens is a fish parasite that predominately infects small juvenile amphipods during winter, while Pseudocorynosoma sp. is a bird parasite that mainly occurs in intermediate to large male amphipods during spring and summer (Rauque & Semenas, 2007).…”