Sphincterodiplostomum musculosum (Digenea, Diplostomidae) infecting Steindachnerina insculpta (Characiformes, Curimatidae) in the Chavantes Reservoir, Southeastern Brazil Sphincterodiplostomum musculosum (Digenea, Diplostomidae) infectando Steindachnerina insculpta (Characiformes, Curimatidae) no reservatório de Chavantes, Sudeste do Brasil

This study aimed to report the infection by Sphincterodiplostomum musculosum metacercariae in Steindachnerina insculpta from the Chavantes Reservoir, medium Paranapanema River, municipality of Ipaussu, State of S&#227;o Paulo, Brazil. Thirty specimens of S. insculpta were collected and 29 were infected with S. musculosum metacercariae (prevalence = 96.67%) in the eyes and visceral cavity. The mean intensity of infection and abundance were 96.6 &#177; 29.41 (7-846) and 93.3 &#177; 28.6 (0-846), respectively. Positive correlation was observed between parasite abundance in the eyes and standard length (rs = 0.5, p = 0.005), total weight (rs = 0.649, p = 0.0001), and condition factor (rs = 0.439, p = 0.0154). The high parasitism rates by S. musculosum metacercariae in S. insculpta can be an indicative that this fish species is highly susceptible to infection by this diplostomid, and even reflect the presence of a large abundance of the intermediate host. Moreover, S. musculosum metacercariae are reported for the first time in S. insculpta.<br>O presente estudo tem como objetivo relatar a infec&#231;&#227;o por metacerc&#225;rias de Sphincterodiplostomum musculosum em Steindachnerina insculpta provenientes do Reservat&#243;rio de Chavantes, m&#233;dio Paranapanema, munic&#237;pio de Ipaussu, Estado de S&#227;o Paulo, Brasil. Foram coletados 30 esp&#233;cimes de S. insculpta, sendo que 29 estavam infectados por metacerc&#225;rias de S. musculosum (preval&#234;ncia = 96,67%) nos olhos e na cavidade visceral. A intensidade m&#233;dia de infec&#231;&#227;o e abund&#226;ncia apresentaram valores de 96,6 &#177; 29,41 (7-846) e 93,3 &#177; 28,6 (0-846), respectivamente. Foi observada correla&#231;&#227;o positiva entre a abund&#226;ncia dos parasitas presentes nos olhos com rela&#231;&#227;o ao comprimento padr&#227;o (rs = 0.5, p = 0.005), peso (rs = 0.649, p = 0.0001) e fator de condi&#231;&#227;o (rs = 0.439, p = 0.0154). As altas taxas de parasitismo de metacerc&#225;rias de S. musculosum em S. insculpta podem ser um indicativo de que esta esp&#233;cie de peixe &#233; altamente suscept&#237;vel &#224; infec&#231;&#227;o por este diplostom&#237;deo, e at&#233; mesmo refletir a presen&#231;a de grande oferta do hospedeiro intermedi&#225;rio. Al&#233;m disso, este &#233; o primeiro relato de parasitismo por metacerc&#225;rias de S. musculosum em S. insculpta.