Prevalence, abundance and morphospecies characterization of leeches (Annelida: Hirudinea) on intertidal fish from central Chile

Abstract

The aim of this study is to describe and compare the morphology and morphometry of leeches from intertidal fish. A total of 2,124 fish specimens that belonged to 15 species were collected from intertidal rocky pools from central Chile. They were externally examined for leeches. Twelve fish species harboured these parasites but only three of them had the sufficient number of individuals to perform morphometrical analyses. Five morphotypes of leeches were classified according to their colour and size; three morphotypes (MT1, MT2 and MT3) were from Scartichthys viridis, a morphotype (MT4) was from Sicyases sanguineus, and another morphotype (MT5) was from Aphos porosus. The five morphotypes were compared using six morphometrical measurements (length and width of the body, diameter of oral and posterior suckers, length of clitellum and position of clitellum from the anterior end). Morphometrical comparisons were based on absolute and relative measurements. The results indicated that MT4 and MT5 differed from the other morphotypes, whereas MT1, 2 and 3 did not differ significantly among them. MT4 had body and suckers wider than the other four morphotypes, whereas MT5 was longer, thinner and with a longer clitellum than the other morphotypes. According to these results, each fish species, of the three analyzed, harboured a distinct morphospecies. These leeches belong to the Piscicolidae family; although it was not possible to identify them at a genus level. This study also provides new records of leeches for nine intertidal fish species of Chile.