Diamond Rajakumar Tenali’s research while affiliated with Andhra University and other places

Ompok bimaculatus (Bloch 1794) is a near threatened catfish of freshwaters, belongs to the family Siluridae of the order Siluriformes. Due to its rich lipo-protein content and soft bony structure it becomes delicious and nutritiously highly valuable food fish species. At present Ompok bimaculatus facing decline in the natural populations, due to several anthropogenic factors such as indiscriminate fishing during the breeding season, unscientific use of pesticide in agricultural fields, gradual siltation in the freshwater habitat, depletion of water velocity as a result of decrease in water volume etc. Because of such drastic reduction in its population and a very restricted distribution in the freshwater ecosystem, Present work aims to an experimental analysis of reproductive biology of Ompok bimaculatus. Standardized knowledge on factors like fecundity, ova diameter, maturity, sex-ratio, and spawning are essential pre-requisites in fishery management and conservation. For understanding the dynamics of the gonads and to assess reproductive performance of species information of the phase of gonad development is virtually important

Garra ngopi sp. n., a new Labeoninae species, is described from the Tinam stream of the Tissa River (district Longding), which is a headwater of the Brahmaputra River basin in Arunachal Pradesh, North–Eastern India. The new species is distinguished from its congeners by the following combination of characters: smooth snout with 7–8 shallow pits forming a pseudo groove structure on anterior most of snout; 4–5 shallow pits on both sides of snout, 2 + 2 shallow pits on rostrum midst of snout; 11–13 shallow pits situated in between nares; dorsal, pectoral and pelvic fins spread with two to four smooth and shallow pits; caudal fin rays spread with numerous shallow pits are very distinct. Head without proboscis; 35–36 lateral line scales; 9–10 predorsal scales; absence of scales on chest and belly. Evidences of genetic analyses (genetic distance, phylogenetic clustering and species delimitation), on the basis of mitochondrial gene (cox1) indicated that the species was distinct from other known congeners.

A new species of Garra (Labeoninae) is described from the Zubza River, a headwater of the Brahmaputra River basin, in Kohima district of Nagaland, North-eastern India. The new species is distinguished by the following combination of characters: a black spot located on the principal ray and first three branched rays of the dorsal (upper) lobe distal part, as well as a black submarginal V-shaped band on the principal ray and whole branched rays of the ventral (lower) lobe of caudal fin; snout with weakly-developed proboscis represented by slightly upwards elevated hump, with no transverse groove and no transverse lobe, and with 10–12 small tubercles on anterodorsal marginal aspect; 34 lateral-line scales including two pored scales on caudal fin; absence of scales on chest and presence of poorly developed scales on belly; relatively shorter caudal peduncle (10.7–12.5 % SL), and snout (34–35 % HL); and relatively larger eye (31–32 % HL).

Morphometric and meristic characteristics of Clupisoma naziri was explored in Gomati River Tripura and the poorly known C. naziri, was newly recorded from the river at 23°33.144’N, 91°36.732’ E, elevation 39 m and 23°31.676’N, 91°39.184’ E, elevation 30m. Morphometric measurements (8 Male and 4 female) show the mean length and weight of the fish is 29.3±3.4cm and 246 ±7.1g respectively. Meristic counts show 40–45 anal-fin rays which is one of the important distinguishing characters of the species. The average water pH of the sampling site observed 6.7–7.2. Dissolved oxygen observed 5.6–6.4 mg/l, Total alkalinity 55–56 mg/l and Transparency observed 15–25 cm. Graphical Abstract Clupisoma naziri is currently considered near threatened by IUCN criteria, and therefore, it is urgent to take conservation measures and to study biological parameters of the fish to protect the fish in nature as well as in culture.

Glyptothorax pongoensis, sp. n. is described from the Yongmon River in Nagaland, India. The new species can be distinguished from its congeners in the Indian subcontinent by the following combination of characters: an ovate-shaped thoracic adhesive apparatus with skin ridges present over the entire apparatus, including the subulate-shaped median depression; presence of plicae on the ventral surface of the pectoral fin spine and the first ray of the pelvic fin; W-shaped anterior nuchal plate element; dorsal-fin origin nearer to the snout tip than to the origin of the adipose fin; posterior margin of dorsal spine rugose with 4–5 ridges, tuberculate skin, and nasal barbel not reaching eye when adpressed.

Glyptothorax punyabratai, a new species, is described from the Brahmaputra River drainage in Arunachal Pradesh, Northeast India. It is distinguished from its congeners by having the following combination of characters: a rhomboidal- shaped thoracic adhesive apparatus with bowling pin-shaped median depression which opens posteriorly; the presence of plicae on the ventral surface of the pectoral spine and first pelvic-fin ray; plump body; depth of caudal peduncle 7.7-8.6 % SL; nasal barbel not reaching the anterior margin of the eye; nuchal plate saddle with arrow-shaped extensions; and three longitudinal stripes on the body.

Mystus tengara is a popular food fish species due to its taste, and one of the potential ornamental fish species in ornamental trades. A total of 237 specimens of Mystus tengara [1] species were collected from Rudra Sagar Lake and Kemtali. 47 food items were observed in the gut of Mystus tengara. The present study has been performed on the food and feeding habits, Gastro Somatic Index, Relative Length of Gut, Fullness and feeding Intensity, and Gut Content Analysis of Mystus tengara. Results of the study revealed that Mystus tengara is a carnivorous fish and zooplankton is the basic food group for this fish species; rotifer has also been observed as the most preferable food class. The species showed isometric growth which indicates the well-being condition of the fish.

Badis singenensis (Geetakumari and Kadu, 2011) is first time recorded from the Darakonda hill stream water bodies of Sabari tributary of River Godavari, Eastern Ghats, Andhra Pradesh, India based on the whole completion of detailed morphometric and meristic data of the collected specimens that form the basis of this new record are presented. Badis singenensis is identified by a unique combination of characteristics such as three distinct black blotches at the base of the dorsal fin: the first is behind the third spine, the second is behind the sixth dorsal spine, and the third is behind the fifth and sixth soft dorsal rays. There is a prominent spherical black blotch positioned postero-dorsally situated on the opercle at the base of the opercle spine, covering many scales. Its close congerners, B. assamensis and B. blosyrus, are distinguished from this species by the black patch at the base behind the fifth soft anal fin ray. lateral line with 29–31 scales.

Length-weight relationships (LWR) are reported for four indigenous fish species of longshen stream, Indo-Myanmar boundary line North-Eastern Ghats of Indian region, for the period of June 2020 to September 2022. Specimen species were collected during different exploratory surveys, using through traditional bamboo made fishing gears. The b value for LWRs varied from 2.09(Barilius vagra)to 2.63(Garra lissorhynchus). R2 values varied from 0.85 to 0.95, indicating unique values. The results providing baseline information for the need of sustainable ecological as well as economical management and conservation of indigenous fish species in Indo-Myanmar borderlines