First Molecular Identification of Caligus clemensi on Cultured Crimson Snapper Lutjanus erythropterus on Jerejak Island, Penang, Peninsular Malaysia.

Zary Shariman Yahaya,Oluwaseun Bunmi Awosolu,Luay Alkazmi,Mohd Nor Siti Azizah,Rajiv Ravi

doi:10.3390/pathogens11020188

Abstract

Fish parasites such as Caligus clemensi are a serious concern for cultured fish in many regions of the world, including Malaysia. This study was designed to elucidate the parasites’ prevalence and intensity coupled with the morphology and molecular identification of C. clemensi on cultured Lutjanus erythropterus in Jerejak Island, Penang, Peninsular Malaysia. The study was carried out on 200 fish specimens of cultured L. erythropterus obtained from the GST group aquaculture farm. Parasites were collected from the infested part of L. erythropterus fish, and their prevalence and intensity were determined. The parasites were identified morphologically using a field emission scanning electron microscope. Molecular studies were performed through PCR amplification and sequencing. MEGA 5 was used to construct a phylogenetic tree using the pairwise distance method. The results showed that only the C. clemensi parasite was found prevalent on L. erythropterus fish with a prevalence and mean intensity (S.D) of 198 (99%) and 36.4 ± 12.2, respectively. The prevalence varied significantly with respect to fish length (p < 0.05). The nucleotide BLAST sequence for 18S ribosomal RNA partial sequences showed 97% with 100% query similarity, E-value 0 with C. clemensi with the accession number DQ123833.1. Conclusively, C. clemensi remains a major parasite of L. erythropterus in the study area.

Highlights

The aquaculture system in floating cages was first established in Penang, Malaysia in
The snapper fish (Lutjanidae) was the commonest species among marine fish cultures reared in the aquaculture industry [1]
All of the C. clemensi parasites obtained from the 200 fish samples were calculated based on a morphological field examination [8,9] with the aid of a dissecting microscope

Summary

Introduction

The aquaculture system in floating cages was first established in Penang, Malaysia in1973. The snapper fish (Lutjanidae) was the commonest species among marine fish cultures reared in the aquaculture industry [1]. The Caligus species is responsible for causing massive mortalities in cultured L. erythropterus due to pathological tissue alterations on the gills and buccal cavity, thereby leading to serious economic loss. They cause serious harm on the host fishes when they feed on the epidermal tissue, blood and mucus of fishes [1,3]

Methods

Results

Discussion

Conclusion