Morphometric Study of the Genus Garra Found in Arunachal Pradesh, Northeast India

Background: The fishes of genus Garra are one of the most abundant and taxonomically confusing groups which requires further studies to evaluate their taxonomical ambiguity. Therefore, the present investigation was conducted on the genus to understand their detailed morphometric and meristic features. Methods: A total of 122 fish specimens belonging to 10 species were collected from the hill stream rivers of Arunachal Pradesh. Eleven morphometric and six meristic parameters were applied for each fish specimen. Identification key was developed after the detailed examination of morphological features. Fin formula was also generated for each species by counting the meristic characters. Phylogenetic tree was developed using morphological characters to understand the evolutionary relationship among the species. Result: Present study observed the maximum length (54.8 - 135.0 mm) in G. annandalei and minimum length (64.1 - 70.2 mm) in G. rufa. And this study also confirmed the presence or absence of lobes and tubercles, rostral cap, proboscis, gular disc and fins’ shape as key identifying features. Constant in morphometric measurements and meristic counts reveals the uniqueness of the species which was noticed from the generation of fin formula. Further, species were assigned with latest IUCN Red data, G. rupecula was identified as NT, 3 species were under NE and 6 species in LC category. Analysis of phylogenetic tree through neighborjoining (NJ) clustering method with bootstraps 100 depicts that G. lissorhynchus, G. rufa and G. rupecula were belonged to the common ancestral group and G. annandalei and G. quadratirostris were distantly related to G. arunachalensis and G. lamta. A strong positive and linear LLRs were found in between TL and other morphometric characters with r value greater than 0.765. SL showed significantly (p less than 0.01) higher correlation with TL in all the species.