Survey and ecology of nematofauna in stranded sea turtles on the northeastern coast of Brazil.

Abstract

The present study aimed to investigate the nematode parasite fauna in 66 stranded sea turtles on the northeastern coast of Brazil between 2010 and 2019. The parasite samples were stored at the Fundação Mamíferos Aquáticos (FMA), which collaborated on this research. The survey covered four species: Chelonia mydas, Lepidochelys olivacea, Caretta caretta, and Eretmochelys imbricata. Six species of nematode parasites were identified. C. caretta showed the highest diversity of nematode species, with Cucullanus carettae being the dominant species. In L. olivacea, Tonaudia freitasi was the dominant species, while in C. mydas and E. imbricata, the dominant species were Kathlania leptura and Sulcascaris sulcata, respectively. Statistical analyses indicated that there was no significant correlation between the size of the turtles' carapaces and the intensity or abundance of parasites in L. olivacea, according to Spearman correlation coefficients. Additionally, the study presents novel data: the first record of C. carettae and A. carettae in Brazil, Contracaecum sp. larvae in sea turtles, and new occurrences of K. leptura, T. freitasi, and S. sulcata. This survey contributes to the monitoring and understanding of the helminth fauna affecting sea turtles on the northeast coast of Brazil.