Identification of helminth parasites from selar crumenophthalmus in Grenada, West Indies

Abstract

Grenada is a tropical island country reliant on local fish for food and export. Specifically, Selar crumenophthalmus, known locally as jacks or bigeye scad, is commonly consumed by residents and visitors to the island. To date, there are no data about the prevalence of different helminths in S. crumenophthalmus in Grenada. In particular, it was unknown if Anisakis, a genus containing parasitic nematodes, implicated in both fish and human disease, is of concern for local fish and human health. In this study, 39 samples of S. crumenophthalmus were dissected and assessed for helminth infection. Of these fish, 26 (67%) contained helminths in and around the internal organs (mean, 3.6 helminths per infected fish). DNA was extracted from each helminth, followed by PCR, restriction fragment length polymorphism analysis, or Sanger sequencing or a combination of them to identify the parasites. Results confirmed that 89 (96%) of 93 helminths identified were Anisakis typica, and the remaining four helminths were likely acanthocephalans. Neither is considered pathogenic to humans, livestock, or companion animals. To our knowledge, this is the first report of either type of helminth in fish in Grenada. Future studies are needed to ascertain the role of A. typica and acanthocephalans in fish health in Grenada, including any association with observed fish kills. Additional studies are also needed to identify other helminths found in S. crumenophtalamus, which may be of importance to its health and also human health.