Ichthyofaunal Diversity from Longline Catches in the Gulf of Mannar (GoM), Southeast Coast of India.

Ravikumar, T.; Neethirajan, N.; Chandran, S.; Sangaralingam, M.; Natarajan, J.; Umamaheswar, T., and Padmavathy, P., 2024. Ichthyofaunal diversity from longline catches in the Gulf of Mannar (GoM), southeast coast of India. Journal of Coastal Research, 40(1), 115–128. Charlotte (North Carolina), ISSN 0749-0208. The present study aimed to document the spatial and temporal ichthyofaunal diversity of reef associated fishes caught with experimental longlines fitted with different "J" hook sizes (no. 12, no. 9, and no. 6) and shapes (Straight, Kirbed, and Reversed) from the Therespuram and Mundhal fish landing centres of Gulf of Mannar (GoM), Southeast Coast of India. Sampling was done at a fortnightly interval from February 2020 to January 2022. The total of 21,322 fish diversity includes 37 species of fish belonging to 15 genera, 10 families, and seven orders have been recorded during the study period. Order wise and species wise landing revealed the dominance of Perciformes with five families (Haemulidae, Lethrinidae, Lutjanidae, Nemipteridae, and Serranidae) and 28 species while in the case of order Centrarchiformes it represented with only one species. Fish diversity of GoM was assessed by calculating the various diversity indices such as Shannon–Weiner biodiversity index (H′) ranged from 2.31 to 3.29, Simpson's Dominance Index (1-λ′) ranged from 1.80 to 4.73, Pielou's Species Evenness index (J′) ranged from 0.90 to 0.99, and Margalef index (d) of species richness ranged from 2.03 to 4.73. The results of the present study revealed that the experimental longlines caught one endangered (3%), four vulnerable (11%), two not evaluated (5%), one data deficient (3%), and 29 species (78%) of least concern as per the International Union for Conservation of Nature status. The assessment is a prerequisite for understanding the biodiversity and to help fishery managers to evolve new strategies for the sustainable exploitation and conservation of coral reef associated fishes in this region. [ABSTRACT FROM AUTHOR]