Abstract
Little information is available about the biodiversity of parasitic copepods in the Arabian Gulf. The present study aimed to provide new information about different parasitic copepods gathered from Parupeneus rubescens caught in the Arabian Gulf (Saudi Arabia). Copepods collected from the infected fish were studied using light microscopy and scanning electron microscopy and then examined using standard staining and measuring techniques. Phylogenetic analyses were conducted based on the partial 28S rRNA gene sequences from other copepod species retrieved from GenBank. Two copepod species, Hatschekia sargi Brian, 1902 and Hatschekia leptoscari Yamaguti, 1939, were identified as naturally infected the gills of fish. Here we present a phylogenetic analysis of the recovered copepod species to confirm their taxonomic position in the Hatschekiidae family within Siphonostomatoida and suggest the monophyletic origin this family. Sequencing the 28S rRNA gene query identified a close relationship of the recovered Hatschekia species to Hatschekia japonica (gb| KR048858.1). This study identifies a new host for Hatschekia species isolated from Saudi Arabia and performs the first molecular analysis of their 28S rRNA genes.