DAO prepress abstract - DOI: https://doi.org/10.3354/dao03821
Characterization of Piscinoodinium sp. associated with epizootics and mortality in non-native and endemic freshwater fish of the Andaman Islands, India
J. Praveenraj, A. Uma, K. Saravanan, B. Ahilan, A. Gopalakannan, D. Manikandavelu, R. Kiruba-Sankar, G. Kumar
ABSTRACT: Piscinoodonium sp. is a well-known parasitic dinoflagellate genus causing epizootics in the tropical freshwater fish. This study investigated the first outbreak of Piscinoodonium sp. in the freshwater fish of Andaman Islands. The infection was noticed in the non-native fish Betta splendens, Poecilia reticulata, and in the endemic killifish Aplocheilus andamanicus. The infection caused mass mortality in larval, sub-adult and adult fish. The parasite was identified based on microscopy and molecular characterization. The prevalence, parasite density, and mortality percentage were recorded. Infected fish had numerous trophonts attached on the body surface, gills, fins and eyes. Infected skin and gills showed degeneration of the epithelial cells and clubbed gills. Small subunit rDNA (955 bp) was amplified from the Piscinoodonium sp. infecting Betta splendens, revealing genetic differences between it and Piscinoodonium spp. from the USA and from India.