PARASITISM IN CHUB MACKEREL SCOMBER JAPONICUS HOUTTUYN, 1782 AND JACK MACKEREL TRACHURUS SYMMETRICUS MURPHYI NICHOLS, 1920 OFF CENTRAL CHILE

Abstract

The populations and infracommunities of metazoan parasites were compared in two sympatric marine fish species in the pelagic realm off central Chile: the chub mackerel Scomber japonicus and the jack mackerel Trachurus symmetricus murphyi. Samples were taken during winter 1997. Chub mackerel were older than jack mackerels in the samples. This may have affected some of the descriptive features of parasitism. For example, infracommunity richness and total parasite abundance were higher in the chub mackerel, and increased with host body size, but not in the jack mackerel. A total of 13 parasite taxa were found in
both host species, 6 of which were shared. Among shared taxa, the abundance and prevalence of Anisakis Type I and Nybelinia sp. were much higher in the chub mackerel, whereas Rhadinorhynchus trachari was more prevalent and abundant in the jack mackerel. The importance of considering the host age when comparing the parasite communities of sympatric host species is discussed.