Acanthocephalan and Trematode Endoparasites in Rabbitfish Siganus fuscescens from the Selected Coastal Areas of Surigao City, Surigao del Norte, Philippines

Abstract

The rabbitfish, Siganus fuscescens, is an economically important fishery in Surigao City, Philippines. This study was conducted to assess the zoonotic potential of the endoparasites infecting S. fuscescens collected from September to November 2021 in the three selected coastal areas of Surigao City, Surigao del Norte, Philippines. Isolated worms were identified using light microscopy and appropriate staining techniques based on their morphological characteristics. Two endoparasite species were recovered from the intestine of the siganids, the acanthocephalan Sclerocollum rubrimaris, and the trematode Hexangium sigani. Single infections of S. rubrimaris were common among fish samples, and an overall prevalence of 45% and a mean intensity of 30±23.34 (N=150) were recorded. The fish length (rs= -0.243) and weight (rs= -0.139) had a significant but weak negative correlation with the parasite load. With prevalence of 100%, results revealed that the Canlanipa station has a significantly higher prevalence of infection (100%) compared to Perlas (14%) and Bilang-bilang (22%). The endoparasites are not zoonotic, yet, intestinal hemorrhage was observed in fish with heavy infections with S. rubrimaris. This study is the first report of endoparasite infection in siganids of Surigao. A survey of endoparasites in other fish species in the coastal waters concerning water quality and heavy metal pollution is recommended.