Larvas de trematódeos emergentes de moluscos dulcícolas de coleções hídricas no município de Pedro II, Piauí, Brasil

Abstract

The class Trematoda comprises helminths that have a complex life cycle, divided in two stages: sexual reproduction in the definitive hosts, mainly vertebrates, and asexual reproduction that occurs in the first intermediate hosts, mainly aquatic mollusks. These animals cause several parasites, such as paragoniasis, clonorchiosis, and echinostomiasis. However, the main disease caused by these parasites is schistosomiasis. This study aimed to identify trematode larvae transmitted by freshwater mollusks in water collections in the municipality of Pedro II, Piauí, Brazil. Freshwater mollusk collections were performed from January to August 2022. The captured mollusks were individually evaluated in the laboratory by means of artificial photostimulation to detect possible infection by trematode larvae. A total of 2603 mollusks were captured, where the following trematode larvae were found: a) Xiphidiocercaria infecting Biomphalaria straminea (Dunker, 1848), Melanoides tuberculata (Müller, 1774) and Pomacea canaliculata (Lamarck, 1822); b) Apharyngeal Brevifurcated Dystoma emerging from B. straminea and P. canaliculata; c) Echinostome in B. straminea; and d) Gymnocephala in M. tuberculata. These malacological survey results demonstrate the diversity of trematode larvae harboring freshwater gastropods in different water collections of the municipality of Pedro II, Piauí, Brazil. Besides reflecting on the ecology of the environment, it is important to have new studies that aim to analyze the associated environmental parameters and biological cycles of helminths.