Brazilian Aspidogastrea (Platyhelminthes, Trematoda): an updated list of species with a temporal and spatial analysis

Abstract

Aspidogastrea is a small group of trematodes found parasitizing mollusks, fishes, and turtles worldwide. Brazil is one of the most biodiverse countries, and some previous studies have presented data on species belonging to this group of trematodes. The goal of the present study was to provide an updated checklist of Aspidogastrea species recorded in Brazil up to August 2025, along with an analysis of temporal variation and spatial distribution of records. For this purpose, data were obtained from previously published works (catalogues and prior studies) and from articles identified through searches conducted in six databases. A total of eight described species and one undetermined species of Aspidogastrea were recorded parasitizing 14 fish species and one turtle species. Among the 25 records retrieved from the literature, most (n = 21; 84%) were associated with marine hosts. Temporal analysis revealed a peak in the number of records in 2010. Most records were reported from studies conducted in the states of Rio de Janeiro (n = 13; 52%) and Rio Grande do Sul (n = 6; 24%). The host Trachinotus marginatus Cuvier, 1832 exhibited the highest parasite richness (n = 2), and Lobatostoma ringens (Linton, 1905) Eckmann, 1932 was the most frequently recorded Aspidogastrea species, occurring in 44% (n = 11) of the fishes. Analysis of accumulated parasite richness indicated that the most recent species record dates from 2017. Based on these data, significant gaps in knowledge regarding Aspidogastrea biodiversity were identified, as well as a limited number of research groups working on this taxon. The present study updates the list of Aspidogastrea species recorded in Brazil and contributes to the knowledge of parasite biodiversity in the Neotropical Region.