Parasite assemblages of Corydoras paleatus in a Pampa Plain stream with contrasting conditions of water quality and habitat

BERTORA, ANDREA; PABLO SANZANO; GROSMAN, FABIÁN; ROSSIN, M. ALEJANDRA; ROSSO JUAN J.

BIOLOGÍA ACUÁTICA

UNLP

Lugar: La Plata; Año: 2021

1668-4869

ABSTRACT. Land uses generate deep changes in aquatic ecosystems, their organisms and thecommunities that parasitize them. In this study we analyze the parasite assemblages of Corydoraspaleatus under contrasting conditions of water quality and habitat of a Pampa Plain stream imposedby urban discharges and livestock. The possible effects of these aspects on some attributes ofthe parasite communities of C. paleatus are discussed. A total of 136 parasites belonging to fourtaxonomic groups were identified: Phylocorydoras platensis (monogeneans), Heterophyidae (larvaldigeneans), Protocephalidea (larval cestodes) and ciliates protozoa (Trichodinidae gen. sp. and Ichthyophthirius cf. multifiliis). Under conditions of urban impact, less richness and diversity wererecorded. Instead, the livestock reach showed larger parasite richness, diversity and equitability,and the presence of monogeneans (P. platensis) and ciliates (Trichodinidae gen. sp.). The digeneanpopulations registered the highest abundance and the populations of cestodes and I. cf. multifiliiswere more prevalent. The deterioration of water quality and instream habitat of the reach closeto the city could explain the impoverishment of parasite communities. A better water quality withinput of organic substrate, slower flow and larger macrophytes development observed under theinfluence of livestock, would improve conditions for establishment of monogeneans and ciliates ingills, digeneans in fins and cestodes in the digestive tube. This study provides a first approach tothe knowledge of the parasite ecology of C. paleatus and the factors that could model or influencethe structure of the parasite communities of this species.