Epidemiology of acanthocephalan infections in crabs from the Bahı´a Blanca Estuary, Argentina

LA SALA, LUCIANO; PEREZ ANDREZ; MARTORELLI SERGIO R

JOURNAL OF HELMINTHOLOGY

CAMBRIDGE UNIV PRESS

Año: 2011 p. 1 - 7

0022-149X

This study was conducted in two populations of crabs, Cyrtograpsus angulatus15 and Neohelice granulata from the Bahı´a Blanca Estuary, in Argentina, to identify16 risk factors for infection by the acanthocephalan Profilicollis chasmagnathi and17 to assess the association between infection and mortality of these hosts.18 Cyrtograpsus angulatus and N. granulata crabs were sampled seasonally over the19 course of a year, and spring sampling included collection of dead crabs predated20 by Olrog’s gulls in a nearby breeding colony. Potential risk factors for infection21 were assessed and the number of cystacanth larvae per crab was counted.22 In C. angulatus, the odds of infection increased by 7% for each millimetre increase23 in carapace length, and were nearly 17 times greater in crabs sampled from the24 Olrog’s gull feeding area compared with those sampled from nests in the25 breeding colony. For every millimetre increase in carapace length in N. granulata,26 the odds of infection increased by 13% in crabs from the breeding colony, and by27 32% in crabs the feeding area. Mean intensity of infection in N. granulata28 increased one unit for each additional millimetre of carapace width. The level29 of parasite aggregation was lowest in the largest C. angulatus and highest in30 N. granulata predated by Olrog’s gull. The results show that host size is the31 most important factor influencing infection prevalence in both crab species32 and intensity of infection in N. granulata, and suggest the presence of parasite-33 induced mortality in the populations studied.