Exploring the Genetic and Morphological Diversity of Argulus Ectoparasite Infecting the Aquaculture and Ornamental Fish in Tripura

Background: The present study screened for isolation of Argulus spp. infecting fishes based on the report of causing substantial economic losses both in aquaculture ponds and ornamental shops across several locations in Tripura, India. Methods: Identification of Argulus spp. was performed based on morphological, and molecular techniques. The molecular identification of Argulus spp. was performed using universal eukaryotic 18S rRNA genetic markers. Prevalence analysis was performed to determine the infestation rate of Argulus spp. in different hosts. Result: Seven A. japonicus, one A. coregoni and one A. foliaceus isolates were identified based on molecular and morphological features. In the present study it was found that A. japonicus infected a wide range of host species, including Goldfish, Milky Koi carp, Mrigal, Rohu, Catla and Subunkin. It was the first instance of A. japonicus infecting milky koi carp both in India and globally. On the other hand, A. foliaceus and A. coregoni infected only tiger oscar and goldfish respectively, indicating a rather narrow range of host diversity.