PROGENESIS IN PROCTOECES LINTONI (FELLODISTOMIDAE), A PARASITE OF FISSURELLA CRASSA (ARCHAEOGASTROPODA) IN A LATITUDINAL GRADIENT IN THE PACIFIC COAST OF SOUTH AMERICA

The fellodistomid Proctoeces lintoni is a common parasite of the gonads of key-hole limpets Fissurella spp. (Archaeogastropoda). It has also been found in the mantle of Octopus vulgaris and as an intestinal parasite of haemulid and gobiesocid fishes. Fissurella crassa, a host for progenetic P. lintoni, can be found from Huarmey, Perú (10°S) to Chiloé, Chile (42°S). Proctoeces lintoni has been found parasitizing fishes and molluscs from Callao, Perú (12°S) to Valdivia, Chile (39°S). Progenesis is thought to be a latitude-dependent phenomenon, and high progenesis is expected at higher latitude. In the present article, the association between latitude and progenesis was examined over a latitudinal gradient of about 3,000 km. Data suggest that progenesis of P. lintoni infecting F. crassa was not associated with latitude. Low levels of progenesis found in the Peruvian population could be a consequence of parasite-induced mortality rather than of low latitude, as would be predicted by the latitude dependence hypothesis.