Study on species composition of parasite in striped catfish (Pangasianodon hypophthamus Sauvage, 1878) based on morphological and genetic characters

Abstract

Striped catfish Pangasianodon hypophthamus is one of the most important export product of Vietnam. The current study focuses on parasite species composition parasitizing P. hypophthamus. Base on the morphological characteristics, 9 species have been detected including 2 species of Myxobolus spp., 2 Ciliophora species (Ichthyonyctus spp.), 2 Monogenea species (Thaparocleidus siamensis and T. campylopterocirrus), 2 Digenea species (Prosorhynchus gracellescens and Bucephalus sp.), and 1 Nematoda species (Cucullanus chabaudi). Using 28S rDNA gene sequences to classify phylogenetic position of T. campylopterocirrus showed close relationship with
T. siamensis and Thaparocleidus sp. (sequence difference are 0.9 and 2.2%, respectively). Phylogram from ITS1 rDNA gene (Internal Transcribed Spacer No 1 of ribosomal DNA) shows that  Bucephalus sp. have a close relationship with B. minimus and B. polymorphus (sequence difference are 10.1% and 34.1%, respectively).