Anil Mohapatra

The freshwater prawn and shrimp fauna of Harishankar Hill stream, a hill stream in the western part of Odisha, was studied. The study reveals the presence of four species of palaemonid prawns and three species of atyid shrimps in the Hill stream, providing detailed and comprehensive information about this ecosystem. Previously, six atyid shrimp species of the genus Caridina have been documented in Odisha. This paper reports Caridina fernandoi Arudpragasam and Costa, 1962 and Caridina gurneyi Jalihal, Shenoy and Sankolli, 1984 for the first time from Odisha state, accompanied by a detailed taxonomic description. With this, the valid atyid shrimp species of the genus Caridina becomes eight from the state.

Gangaichthys indonepalicus gen. et sp. nov ., is described from the Indo-Gangetic Plain, Bihar, India. This is the first stygobitic chaudhuriid and first subterranean fish from the alluvial aquifers of the Gangetic Basin and Indo-Gangetic Plain, with all three specimens collected from borewells. As the first subterranean member of the family Chaudhuriidae it is readily diagnosed from other genera and species of the family by a unique set of morphological characters linked to its stygobitic habit such as reduced eyes, the complete absence of body pigmentation, and apparent absence of ribs. In addition to its stygobitic characters, Gangaichthys is distinguished from all known chaudhuriid genera by the following osteological characters: neural spines laterally narrow and tapering to a point posteriorly or dorso-posteriorly, no spinelike projection on neural arch in front of neural spine; preorbital extension of ectopterygoid does not reach beyond coronoid process of dentary; metapterygoid elongate. Gangaichthys indonepalicus gen. et sp. nov . may further be distinguished from all known chaudhuriid genera and species by the presence of 64 vertebrae (28 abdominal, 36 caudal), and in having a single pectoral fin-ray, six caudal fin-rays, 37 dorsal, and 35 anal fin-rays. Molecular data place Gangaichthys indonepalicus gen. et sp. nov . within Chaudhuriidae, and it is > 20% divergent from two genera of the family for which there is comparative mitochondrial CO1 sequence data.

Taxonomy of sting rays shows an interesting puzzle to be solved since many members of family Dasyatidae are morphologically indistinguishable and a large variation exists with growth. This morphological ambiguity requires molecular studies for identification of species. Morphological identification backed by mtDNA COI gene barcoding demonstrated the occurrence of the Critically Endangered plain-coloured species, Maculabatis arabica (Pakistan whipray) for the first time along mid-eastern coast of India (Odisha and Andhra Pradesh). Maculabatis arabica is a plain brown coloured stingray characterized by absence of white spots at its tail base, one to three large, seed shaped mid-scapular denticle with absence of a primary denticle band and an incompletely banded tail with a black distal caudal region. DNA barcoding of the COI gene segment resulted in confirmation of this taxonomically ambiguous species which is often confused with its congener M. gerrardi. Since immature individuals were observed in this study, continuous exploration should be carried out to confirm the presence of adult population along the coast. The present study has major implications on the threatened category of M. arabica since this study confirms the occurrence of M. arabica throughout the Northern Indian Ocean. The study also throws light on the rich elasmobranch faunal assemblage in Bay of Bengal and provides motivation to carry out future exploratory studies with a focus on mapping the occurrence of endangered elasmobranch species.

The present study provides the first occurrence record of two fish species having elongate bodies, the Indian mud moray, Gymnothorax tile (Hamilton 1822) (Family Muraenidae) and the Gangetic swamp eel, Ophichthys cuchia (Hamilton 1822) (Family Synbranchidae), from the Chilika lagoon. This also evidenced the first occurrence of the genera Gymnothorax and Ophichthys in the lagoon. With this addition, the ichthyofaunal diversity of Chilika lagoon increases to 387 species. Detailed morphometric and meristic characteristics of both species are presented for correct identification.

The present study provides evidence of Lutjanus arakan Hasan, Durand & Iwatsuki 2025 from Indian waters, based on a specimen collected from the Gopalpur coast, Odisha. The combination of distinct colouration, meristic counts, and genetic simillarities provides strong evidence supporting the recognition of Lutjanus arakan from the Indian Ocean.

The study confirms a significant biogeographic extension of the goby species Drombus key (Smith) in Indian waters from the Western Indian Ocean to the Northern Bay of Bengal based on nine specimens collected from the mudflat region of the Bahuda estuary, Odisha. The transitional zone of the Bahuda estuary represents an active interface between marine and freshwater systems. The transitional zone experiences extreme salinity fluxes for which some dominant ichthyofaunal assemblages occur like gobies. The species D. key has the unique character of a triangular yellow mark before a black blotch on the pectoral fin upper base. The species was earlier reported from East Africa to Seychelles and Madagascar, and the present study reported the species for the first time from the Indian coast. Additionally, the species D. key has no genetic data in prior studies and this study also adds four COI gene barcodes of the species, which will contribute towards the potential use of the barcode data library.

The leucosiid crab species Lyphira ngankee Rahayu and Ng, 2024 [type locality: Nanao Island, Guangdong, China], is reported for the first time in Indian waters based on one male and three female specimens collected from trawler bycatch at the Bahabalpur Fish Landing Centre of the Odisha state, and which likely originated from the Bay of Bengal. This is also the first record of the species since its description and a significant range extension from the South China Sea to the eastern Indian Ocean. Lyphira ngankee is distinguished by having a pair of endostomial spines, larger tubercles on the hepatic, branchial and intestinal regions and the slender, distally dilated tip of first male gonopod. Three species of the genus Lyphira were previously reported from India; the record of this species increases the number to four.

We recorded three eel species: Ophichthus lithinus (Jordan et Richardson, 1908), Ophichthus chennaiensis Das, Mohapatra, Rajendar et Bhaskar, 2020, and Cirrhimuraena indica Mohapatra, Mohanty, Ray, Mishra et Seth, 2021 for the first time from the Arabian Sea from the deep waters (300–600 m) of the south-western India off Kerala. Notably, this is the additional documented distributional record of C. indica and O. chennaiensis since their descriptions. The study also provides morphometrics detailed descriptions of all three species.