Community ecology of the metazoan parasites of the Atlantic anchoveta, Cetengraulis edentulus (Actinopterygii: Engraulidae) from the Sepetiba Bay, Rio de Janeiro, Brazil

The Atlantic anchoveta, Cetengraulis edentulus (Cuvier, 1829) is one of the most commercially important fish species in the littoral of Brazil. The present study evaluates the parasitic fauna of this engraulid fish from the southeastern Brazilian coast. Between October 2019 and March 2020, a total of 100 specimens of C. edentulus from the Sepetiba Bay, Rio de Janeiro, Brazil (22 degrees 57'44 '' S; 43 degrees 52'28 '' W), were examined. Eighty-five specimens of C. edentulus were parasitized by at least one species of metazoan, with a mean of 4.32 +/- 6.12 parasites/fish. Eleven species of parasites were collected: five digeneans, two monogeneans, two copepods, one isopod and one nematode. The nematode Hysterothylacium sp. was the most abundant and dominant species, representing 51.85% of the metazoan parasites collected, showing positive correlation with the host's total length and parasite abundance and prevalence. The mean abundance and prevalence of Hysterothylacium sp. was significantly higher in female hosts. One pair of larval endoparasites showed positive covariation. Centengraulis edentulus represents a new host record for nine species of parasites. A dominance of endoparasitic larval stages is documented in the parasite community of C. edentulus. This may be a function of the feeding habits of engraulid fish, which feed mainly on zooplanktonic organisms. It may also have to do with to the fact that C. edentulus is the intermediate and/or paratenic host of fish parasites, birds, and marine mammals.

Automated summary

This study evaluates the parasitic fauna of the commercially important Atlantic anchoveta, Cetengraulis edentulus, in the southeastern Brazilian coast. The study identifies eleven species of parasites, with the nematode Hysterothylacium sp. being the most abundant. Hysterothylacium sp. shows positive correlation with the host's total length and parasite abundance and prevalence, and its abundance is significantly higher in female hosts. This is the first report of C. edentulus acting as the host for nine species of parasites.