Biodiversity of parasites found in the trahira, Hoplias malabaricus (Bloch, 1794), collected in the Batalha River, Tietê-Batalha drainage basin, SP, Brazil

Abstract

Eighty-one Hoplias malabaricus specimens were collected between February 2014 and June 2016. A total of 29 species of metazoan parasites were found, 13 of which were identifi ed as monogeneans, seven were digenean species, seven of which were nematodes, and two of which were from the subclass Hirudinea. The highest prevalence values were presented by Contracaecum sp. and Tylodelphys sp. The highest mean abundance and mean intensity was recorded by Tylodelphys sp.; the values were 36.7 ± 61.8 and 55.65 ± 69.1, respectively. The abundance of the monogenean Urocleidoides cuiabai was found to be positively correlated with host weight. The abundance of Bucephalidae gen. sp. exhibited signifi cant positive correlations with host weight and length. For Contracaecum sp., a signifi cant negative correlation was found between its abundance and host length and weight. No signifi cant differences between the diversity indexes (Margalef, Pielou and Shannon) of the parasites collected in the two points were found. The Sorensen similarity index, with a value of 0.82 between the two sampling points revealed that the parasitic diversity between them is similar. The fi ndings from this study represent new records of occurrence of H. malabaricus, as well as of Urocleidoides margolisi, Scleroductus sp. and Helobdella sp.

Biodiversity of the metazoan parasites of hoplias malabaricus (Bloch, 1794) from the Jacaré-Pepira River, Tietê-Jacaré River Basin, São Paulo State, Brazil

“…The richness accumulation curve of the observed species and the richness estimator did not reach the asymptote, following the same patterns found in studies carried out by Gião et al (2020), Pelegrini et al (2018), and Leite et al (2018) with other hosts, and with H. malabaricus in the same region where the Jacaré-Pepira River is inserted. This may be an indicator that even with a larger number of hosts analyzed and with new studies such as that of Lehun et al (2020), who identified and classified 315 parasite taxa, of which 201 were identified at species level, the biodiversity of the parasitic communities in rivers of the Upper Paraná River basin is not yet fully known, which intensifies the importance of studies on the characterization of ichthyofauna for that region.…”

“…Parasitic communities showed high species richness (d=0.88), diversity (HB=0.66), and equitability (Jʹ=0.83), when compared to the values found by Gião et al (2020) (d=0.71, HB =0.52, Jʹ=0.55), who carried out a survey of the parasitic metazoans of the same host in the Batalha River, state of São Paulo, with a number of specimens of H. malabaricus analyzed almost three times higher than the number of analyzed fish in the present study, and with 29 different species of parasites, 7 species more than those found in the present work. These high values, especially of equitability, found in the present study demonstrate that despite the number of species found being smaller compared to that found by Gião et al (2020), they are more equitably distributed. Hysterothylacium sp.…”

“…The genus Urocleidoides was the one with the highest number of recorded species (Urocleidoides cuiabai, Urocleidoides brasiliensis, Urocleidoides malabaricusi, Urocleidoides eremitus, and Urocleidoides naris), the same number of species described by Gião et al (2020) in Rio Batalha, also belonging to the Upper Parana River Basin, and also by Ferreira et al (2018) in six coastal river locations in the northeastern sector of the state of Pará (Eastern Amazon). According to Rosim et al (2011), the presence of several species of the genus Urocleidoides can be interpreted by their high capacity for colonization and speciation in several individuals of different species and families.…”

“…The data obtained in the present study are the first records of the parasitic fauna of H. malabaricus for the Jacaré-Pepira River and have a relatively high diversity of species, mainly of ectoparasites of the Monogenea class. These higher rates for monogenean parasites are due to the habits of its larvae stages, which are found, most of the time, in lentic environments, which facilitates their transmission in hosts (Yamada et al, 2007), since H. malabaricus is also considered a species of environments with low current and abundant vegetation (Azevedo and Gomes, 1943;Gião et al, 2020).…”

“…Despite not having morphological adaptations, the species has the ability to survive in environments with low oxygen rates, which explains its great dispersion (Barbieri, 1989). It is a predatory species of the "sit and wait" type, a solitary hunter of benthic habits, being found in shallow waters near submerged or marginal vegetation (Gião et al, 2020). As an adult, trahira feeds mainly on other fish, while juvenile individuals feed on plankton (Paiva, 1974).…”