Evaluating the role of dietary plant extracts to allow adaptation to thermal stress in a cold stream ornamental fish, Botia rostrata (Günther, 1868).

Increases in ambient temperature affect the biochemical status of fish, and dietary supplementation with bioactive phytoconstituents may promote resilience against environmental stress. This study evaluated the impact of three plant extracts on the biochemical status of a cold stream fish Botia rostrata (Günther, 1868) under high temperatures. After 1 month dietary supplementation separately with Mucuna pruriens methanol extract (0.25 g/kg feed), Tribulus terrestris ethanol extract (0.5 g/kg feed) and Basella alba ethanol extract (1.0 g/kg feed), juvenile fish (Wt. 4.3 ± 0.5g) were exposed to different sublethal heat stress [28 ± 0.5 °C (T1), 32 ± 0.5 °C (T2), 36 ± 0.5 °C (T3)]. Control fish were fed a diet without any plant extract and maintained at 24 ± 0.5 °C. Serum and muscle tissues were collected to measure different biochemical parameters, muscle metabolic enzymes and molecular chaperons before and after heat stress. Before stress, the group fed the Mucuna diet showed significant (P < 0.05) increases in serum glucose [+10.92%], protein [+18.93%], muscle heat shock protein (HSP) 90 [+8.6%] compared to the control group. No significant change (P > 0.05) of stress parameters was observed between control, Tribulus and Basella fed fish. The control group exposed to T3 showed significant differences (P < 0.05) in protein [-26.19%], lactate dehydrogenase [+93.69%], fructose 1,6 bisphosphate [-35.19%], phosphorylase 'a' [+35.72%], HSP60 [+69.54%], HSP70 [+84.85%], HSP90 [+92.07%], heat shock factor (HSF) 1 [+88.48%] suggesting susceptibility of Botia to this temperature. Among the three plant extracts, Mucuna methanol extract was effective to enhance resistance against temperature-induced biochemical alterations. After exposure to T3, only the fish fed Mucuna diet showed no mortality. Fish fed Mucuna diet exposed to 36 ± 0.5 °C showed significantly higher (P < 0.05) glucose [+42.82%], protein [+11.98%], citrate synthase [+59.81%], phosphorylase 'a' [+14.96%], Glucose 6 phosphate dehydrogenase [+60.87%], HSP60 [+34.13%], HSP70 [+41.42%], HSP90 [+65.91%], HSF1 [+61.32%] compared to those in Mucuna fed fish maintained at 24 ± 0.5 °C. These results highlight temperature-induced biochemical alterations in Botia and point towards the potential use of Mucuna in overcoming such adverse high thermal stress.

Paracanthocobitis hijumensis, a new species of zipper loach from the Arunachal Himalaya, northeastern India (Cypriniformes: Nemacheilidae).

Paracanthocobitis hijumensis, new species, is described from the Hijum River, a tributary of the upper Brahmaputra River in Arunachal Pradesh, India. Paracanthocobitis hijumensis is distinguished from all five species of the P. zonalternans species complex, viz., P. zonalternans, P. nigrolineata, P. marmorata, P. triangula, and P. phuketensis in having a larger body size (46.5 65.6 mm SL vs. < 45 mm SL), and a complete (vs. an incomplete) lateral line terminating at the end of caudal peduncle (vs. at or just beyond the dorsal-fin insertion); and from the four species of the P. mandalayensis species complex, P. canicula, P. maekhlongensis, P. mandalayensis and P. pictilis in having a subortibal flap (vs. suborbital groove) in males, and in having fewer dorsal-fin branched rays (910 vs. 1013), and longer head (23.826.0% SL vs. 18.020.2). Paracanthocobitis hijumensis, a member of the P. botia complex, differs from the other nine species of this complex by the following combination of characters: presence of an axillary pelvic lobe, greater predorsal distance 47.951.8% SL, greater prepelvic distance 52.358.8% SL, longer head 23.826.0% SL, deeper body 18.423.1% SL, smaller eye 14.222.5% SL, and fewer branched rays on the dorsal-fin 9 (12)10 (1).

Redescription of Sartoriana trilobata (Alcock, 1909) (Crustacea: Decapoda: Brachyura: Gecarcinucidae) from Assam, Northeast India, with notes on the morphology of male gonopods.

Sartoriana trilobata is a species of freshwater crab which occurs exclusively in some areas of Northeast India. Being a riverine crab, it is occasionally found in beels or other riverine wetland habitats formed by monsoon floods in the Brahmaputra basin.The earlier descriptions of this species were mostly incomplete which lacked information on the morphology of the male gonopods.Therefore including the male gonopods, all the morphological features of Sartoriana trilobata are redescribed and illustrated. This species differs considerably from its only congener i.e., Sartoriana spinigera through suits of carapace, chelipeds, gonopods dissimilarities.

Exostoma kottelati, a new species of catfish (Teleostei: Sisoridae) from Arunachal Pradesh, India.

Exostoma kottelati, new species, is described from the Ranga River, Brahmaputra basin, in Arunachal Pradesh state, northeastern India. It differs from congeners in the Brahmaputra River basin in having a longer adipose-fin base (33.4-36.0 % SL vs. 23.4-32.9), a greater (except E. mangdechhuensis) pre-pelvic length (45.6-47.3 % SL vs. 39.3-44.6) and a greater pre-anal length (73.9-76.5 % SL vs. 62.2-70.1). It further differs from all known congeners by the following unique combination characters: the adipose fin is distinctly separated from the dorsal procurrent caudal-fin rays, pre-dorsal length 38.9-41.7% SL, adipose-fin base length 33.4-36 % SL, caudal peduncle length 18.7-21.1 % SL, caudal peduncle depth 8.8-9.5 % SL, and body depth at anus 12.5-13.5 % SL. This is the fifth species of Exostoma known from the Brahmaputra River basin.

Mystus prabini, a new species of catfish (Siluriformes: Bagridae) from Arunachal Pradesh, north-eastern, India.

Mystus prabini, new species, is described from the Sinkin and the Dibang River in the Lower Dibang Valley District of Arunachal Pradesh, India. The new species differs from all South-Asian congeners except M. bleekeri, M. cavasius, M. zeylanicus,  M. falcarius, M. seengtee, M. cineraceus, M. ngasep, M. rufescens and M. ankutta in having a long adipose fin that reaches anteriorly (vs. distinctly does not reach) the base of the last dorsal-fin ray. The new species can be distinguished from the named nine species in having (vs. lacking) a narrow black mid-lateral stripe extending from the anterior region of tympanic spot to the rounded black spot at the caudal-fin base. The analysis of mitochondrial cytochrome c oxidase subunit I (COI) gene sequence shows that the K2P value between Mystus prabini and all other Mystus species ranges from 8.6-22.1%. Mystus prabini is closest genetically to M. bleekeri and M. albolineatus, from which species it has a genetic distance of 8.6% and 13.9%, respectively. The genetic distance (K2P) between the new species and M. dibrugarensis is 21.1%.

Physoschistura harkishorei, a new species of loach from Arunachal Pradesh, north-eastern India (Teleostei: Nemacheilidae).

Physoschistura harkishorei, a new species of nemacheilid loach, is described from the Dibang and Lohit Rivers of Arunachal Pradesh, north-eastern India. The new species can be distinguished from all known congeners by the combination of the following characters: the second branched ray of pectoral fin with a distal filamentous extension; body colour pattern consisting of 9-10 vertically-elongated brownish spots or blotches along the flank, and 8-10 brownish saddles on back, the saddles not contiguous with the lateral blotches; lateral line complete; prominent, well-developed pelvic-fin lobe; a well-developed free posterior chamber of the air-bladder; and caudal fin with 7+8 branched rays. The new species occurs sympatrically with Physoschistura dikrongensis and P. elongata in the Brahmaputra basin.

Amblyceps waikhomi, a New Species of Catfish (Siluriformes: Amblycipitidae) from the Brahmaputra Drainage of Arunachal Pradesh, India.

Amblyceps waikhomi sp. nov. is described from the Nongkon stream which drains into the Noa Dehing River, a tributary of the Brahmaputra River, in Arunachal Pradesh, India. The new species can be distinguished from congeners (except A. torrentis) in having a deeper body depth at anus. It further differs from congeners (except A. mangois and A. serratum) in having fewer vertebrae, from A. mangois in lacking (vs. having) strongly-developed projections on the proximal lepidotrichia of the median caudal-fin rays, and in having a longer, wider, and deeper head; and from A. serratum in having a posteriorly smooth (vs. with 4-5 serrations) pectoral spine, and unequal jaw length (lower jaw longer and weakly-projecting anteriorly vs. equal upper and lower jaws). It additionally differs from A. murraystuarti, A. torrentis, A. apangi, A. laticeps, and A. cerinum in having a deeply forked (vs. emarginate or truncate) caudal fin. This species is the seventh amblycipitid species known to occur in the Ganga-Brahmaputra River system.

Physico-chemical qualities of water in high altitude rice fish farming system of Ziro valley, Arunachal Pradesh, India.

Water in rice fields of mountain valley of Ziro, Arunachal Pradesh was investigated for physico-chemical characterization during rice fish farming season (Kharif) of 2013. Water temperature, dissolved oxygen, biological oxygen demand, free carbon dioxide, nitrate-nitrogen, phosphate-phosphorus, chloride, total hardness, calcium hardness, alkalinity, pH, total dissolved solids, specific conductivity and water depth were studied. This study revealed that the physical parameters of water in rice fields like water temperature, pH, total dissolved solids, specific conductivity and water depth were 23.5-31.3 degrees C, 5.9-6.9, 250.34-370.5 mgl(-1), 437.75-660.33 µScm(-1) and 3.72-16.9 cm respectively. The chemical features like dissolved oxygen, biological oxygen demand, free CO2, nitrate-nitrogen, phosphate-phosphorus, chloride, total hardness Ca hardness, alkalinity were 2.4-12.9 mgl(-1), 1.5-11.1 mgl(-1), 9.7-23.35 mgl(-1), 1.28-3.9 mgl(-1), 0.005-0.539 mgl(-1), 16.6-46.8 mgl(-1), 13.9-34.5 mgl(-1), 9.6-13.53 mgl(-1) and 23.16-43.34 mgl(-1) respectively. On the other hand, investigation on planktonic life forms indicated the presence of 13.5x10(3)-84.9x10(3) indl(-1)" and 1.23x10(3)-4.86x10(3) indl(-1) phytoplankton and zooplankton respectively during the Kharif season. The above physiochemical parameters were found to be conducive for raising fish as companion crop of rice due to occurrence of diversified planktonic life forms in underneath water.

Glyptothorax mibangi, a new species of catfish (Teleostei: Sisoridae) from the Tisa River, Arunachal Pradesh, northeast India.

Glyptothorax mibangi, a new sisorid catfish, is described from the Tisa River of Arunachal Pradesh, India. The new species can be distinguished from its congeners in the Ganga-Brahmaputra and Barak-Surma-Meghna basins by the following combination of characters: an obtuse leaf-shaped thoracic adhesive apparatus with a spindle-shaped median depression, skin ridges present over the entire apparatus including the depressed region; ventral surface of pectoral spine and first pelvic-fin ray non-plaited; slender body with depth of 10.4-13.5% SL; caudal peduncle shallow with depth 6.8-8.3% SL; snout long with length 52.9-58.6% HL; and 2+7 gill rakers on the first branchial arch.