Record of Copepod Parasite (Pennellidae) in Buccal Cavity and Gill Arch of Cultured Groupers, Epinephelus spp. in Batam, Indonesia

Abstract

The crustacean parasites are the most frequently encountered and cause significant economic loss in mariculture. These parasites infect fish fin, skin, gills, and buccal cavity. This study aims to describe copepod parasite in the buccal cavity of cultured groupers, Epinephelus spp., from Batam waters using morphological and molecular biology approaches. The tiger grouper, Epinephelus fuscoguttatus (Forsskal, 1775), and hybrid grouper, Epinephelus sp. showing lethargy and skin darkening were collected from sea cages. The parasite’s morphology was observed using light and scanning electron microscopes. The genomic DNA was isolated from the parasites and used as a template for amplification of cytochrome oxidase subunit-1 (Cox1) gene and followed by sequencing. The fish exhibited red nodules in the mouth cavity, on the lips, and gill arch in varying numbers and size of nodules. The copepodid, chalimus, and adult copepod stages were found from the nodule. Based on the presence of the oral cone, this parasite belonged to Siphonostomatoida order of copepods. Based on the structure of the caudal ramus with four long and four short setae, the first and second pair legs as biramous, and the third pair leg as uniramous, this parasite belonged to Pennellidae family of copepods. Basic local alignment search tool analysis of this Cox1 showed low homology within 80%, indicating that the DNA sequences of the parasite species were not reported in the GenBank. The unweighted pair group method using arithmetic average phylogenetic trees supported that this parasite belonged to the family Pennellidae. This is the first report on the pennellid parasite infection in the buccal cavity and gill arch of cultured groupers in Batam, Indonesia.