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Labeo bata fry were reared in high-density polyethylene (HDPE) pens at different stocking densities to determine growth, survival, feed utilization efficiency and economics in Borkona beel, Barpeta, Assam. Pens (500 m2 each) were stocked with fry at four stocking densities, 3 (SD3), 5 (SD5), 7 (SD7) and 9 (SD9) no. m−2 in triplicates. Feeding was performed twice a day at a rate of 3–5% body weight with floating pelleted feed containing 28% crude protein. Fish grew from 2.38 ± 0.30 g to 82.78 ± 3.18, 75.94 ± 0.89, 71.94 ± 0.89 and 61.81 ± 3.35 g at stocking densities of 3, 5, 7 and 9 no. m−2, respectively. Weight gain per cent ranged from 2491.85 ± 140.56 to 3371.33 ± 133.16 and specific growth rate from 1.41 ± 0.02 to 1.55 ± 0.02, both of which decreased with increasing stocking density. The net and gross yields increased with increasing stocking density and were highest at SD9. The benefit-cost ratio was maximum at SD7 (1.42), followed by SD9 (1.41). Post-pen culture, the monthly income of fishers increased by 6.10% (SD3) to 40.50% (SD9). Significant differences (p > 0.05) in water quality parameters were not observed between treatments (inside pens) and reference site (outside pen at 10 m distance). Weight gain exhibited a significant positive correlation with temperature (r = 0.92; p = 0.029) and alkalinity (r = 0.95; p = 0.014). The present study can provide impetus towards species diversification in pen enclosures, income enhancement of small-scale wetland fishers and sustainable ecosystem-based floodplain wetland fisheries management.

The occurrence, abundance, and distribution of phytoplankton have been investigated upstream and downstream of three barrages on the river Ganga at Bijnor, Narora, and Kanpur in Uttar Pradesh, India. A total of 104 phytoplankton species belonging to eight phyla (Bacillariophyta, Charophyta, Chlorophyta, Cryptophyta, Cyanophyta, Euglenophyta, Miozoa, and Ochrophyta) were identified during the sampling period. During the summer, monsoon, and post-monsoon seasons, the density of phytoplankton (Ind. L

The rapid degradation, overexploitation and encroachment of floodplain wetlands have led to considerable decline in fish diversity and production from these invaluable aquatic resources threatening livelihood of the dependent fishers. The climate change evident in the fast few decades have further aggravated the problem of eutrophication causing water stress, sedimentation leading to rampant macrophyte proliferation affecting ecological and economic functioning of these ecosystems. Macrophyte control and management needs serious attention for sustaining ecosystem services provided by these resources. In this direction pen culture of grass carp, Ctenopharyngodon idella as a biocontrol for macrophytes along with Indian major carps was implemented in a co-management mode in Beledanga, a typical floodplain wetland, a gradually shrinking, macrophyte dominated floodplain wetland in lower Ganga basin. Indian major carps Labeo catla (6.28±0.23g), Labeo rohita (5.1±0.12g), Cirrhinus mrigala (3.5±0.08g) were stocked in the ratio 4:3:3 at the rate of 20 no./m2 in pens (0.1ha each) in triplicate. Grass carp (7.1±0.42g) was stocked in pen at the rate of 20 no./m2. The fishes were fed with pelleted feed twice a day at the rate of 2-3% of body weight per day. The seed was overwintered in pens for a period of 90 days from November 2019-January 2020. Average weight recorded at the end of culture period was 25.13±1.70g, 18.11±0.63g, 14.53±0.87g and 39.20±1.90g in L. catla, L. rohita, C. mrigala and C. idella respectively. The survival of fish ranged from 70 to 81%. Growth performance and feed utilization efficiency of grass carp was significantly higher (p

India is blessed with vast floodplain wetland resources of 0.5 million ha that are distributed in the Eastern and North Eastern States. They possess varying morphometry, ecological profile, trophic...

Deepor beel (Latitude: 26°05?26??N to 26°09?26?? N; Longitude: 90°36' E to 90°41?25?? E) located in Kamrup district, Assam is a large (water spread area of 589 ha) natural wetland and a Ramsar site of international importance (Site number 1207 declared in 2002) having enormous biological and environmental importance. The wetland receives water from surface run-off as well as from two hill streams (Basistha and Kalamoni) and drains into River Brahmaputra, through a small rivulet (Khanajan). The beel supports a number of endemic endangered and threatened animals and plants that are included under IUCN red-list. Past studies indicated the occurrence of 67 fin-fish species in the beel. In a recent survey conducted by us, the beel Bangana dero (Synonyms: Cyprinus dero/ Labeo dero), a cyprinid fish, was collected for the first time from the beel. We collected as many as 28 specimens of B. dero from the beel during October 2016. The total length of the reported specimens ranged from 8.77 - 10.14 cm and weight ranged from 6.74 - 10.61 g. The length-weight relationship of the species was worked out as W = 0.074*L2.103. B. dero reportedly inhabits upland rivers, torrential hill-streams; adults migrate to warm downstream regions during the winter season (December-February). Thus, the occurrence of this species in Deepor beel indicates its possible downstream migration from one or both the feeder rivers (Basistha and Kalamoni) or migration from Brahmaputra River through its connecting channel.

Studies on Sisorinae systematics have been largely restricted to morphological data with few studies on examination of phylogenetic relations. However, no study has been done to evaluate genetic distance of the genera under Sisorinae sub-family and detailed phylogenetic relations within it. We used nuclear recombination activating 2 (rag2) gene and mitochondrial cytochrome c oxidase I (COI) gene from 64 species to examine genetic differentiation and phylogenetic relationships within 11 Asian Sisorinae genera. The range of interspecies K2P distance for rag2 was 0-0.061 and COI was 0-0.204. Phylogenetic analysis based on maximum likelihood (ML) and Bayesian (BI) approaches for each locus individually and for the concatenated rag2 and COI sequences revealed three major subclades viz. Bagariini, Sisorini and Erethistini under subfamily Sisorinae. The analysis based on COI gene showed ((Sisorini, Bagariini), Erethistini) relationship. Rag2 and combined rag2 and COI showed ((Sisorini, Erethistini), Bagariini) relationship. Combined rag2 and COI analyses resulted into better resolved trees with a good bootstrap support. In this study, new record of Pseudolaguvia foveolata (Erethistini) has been documented based on 13 specimens collected from Torsa River, Jaldapara, Alipurduar district, West Bengal, India (26°43'44.66″ N and 89°19'32.34″ E), extending its distribution range in Brahmaputra drainage, India. The genetic distance between the P. foveolata new record and the reported P. foveolata (holotype: UMMZ 244867) was 0.00 at both rag2 and COI locus and it was further grouped with P. foveolata Type specimen (holotype: UMMZ 244867) with 100% bootstrap support. This report gives additional information on occurrence of the species P. foveolata, along with discussion on morphometric, meristic and molecular (COI and rag2 gene) data.

Barilius torsai is described from the Torsa, a tributary of Brahmaputra River system in West Bengal, India. The new species is distinguished from all its congeners by the presence of a complete lateral line with 52–53 scales, 29 pre-dorsal scales, pectoral fin notched, two well-developed pairs of barbels (rostral and maxillary), length of rostral barbel slightly larger than maxillary, which reaches the orbit. Tubercles on snout and lower jaw absent, 9–11 blue vertical bars along the body, dorsal fin hyaline with dark pigment concentrated along lower two-third of the dorsal-fin rays.

Studies were carried out from April 2016 to March 2017 for effective understanding of diversity combined with environment-influenced spatiotemporal dynamics of microfloral structure inKailash Khalwetland of Indian Sundarbans. A total of 36 phytoplankton genera were recorded from the study area. Eight major algal groups were in order of: Bacillariophyceae > Cyanophyceae > Chlorophyceae > Coscinodiscophyceae > Xanthophyceae > Euglenophyceae > Conjugatophyceae > Mediophyceae with respect to their quantitative abundance. Mean seasonal abundance was found highest in pre-monsoon (4.32 × 103 cells l−1) followed by post-monsoon (3.88 × 103 cells l−1) and monsoon (1.96 × 103 cells l−1). One-way ANOVA showed that seasonal difference in physicochemical parameters was statistically significant for temperature, DO, specific conductivity, TA, TS, Ca++, nitrate, transparency, salinity, TH, turbidity, Mg++and phosphate (p

Chronic diseases have been treated using the phytochemical concepts of ethnomedicinal plant-derived herbal products. Terminalia arjuna, a significant ethnomedicinal plant, was revisited and reconnoitred for antioxidant, free radical scavenging, and DNA nicking inhibiting activity under H2O2 conditions using 21 solvent extracts. Ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid, and nitrous oxide scavenging (%) were found to have a strong positive association and interaction (PCA 1 explains 84.54% variation) with ethanol bark (Etoh-AB) (Meoh-AF). TPC (144.67–1794 µg/mL GAE) and TFC (2.5–34 µM Fe(II)/g were highest in Etoh-AB. In a pattern of combined solvent extracts, Etoh-AB had the highest antioxidant capacity, accompanied by Etoh-AL ≥ Meoh-AB ≥ Dw-AF. With R2 = 0.94, the DNA nicking inhibition behaviour parameters relative front, relative quantity, band (%), and lane (%) formed a positive significant (p m/z 170.0208 g/mol) and Ellagic acid (m/z 302.0063 g/mol were present in high concentrations in solvent extracts. 0.48 mg was found to be the effective concentration for inhibiting relative DNA nicking. The current study is the first of its kind to show that steroid concentrations are higher in bark fractions of acetone, ethanol, and methanol. Furthermore, T. arjuna solvent extracts provide a wealth of information on phytochemical profiling, antioxidant ability, and DNA nicking inhibition, which may be useful for exploring the natural way and further research to develop a remedy against geriatric chronic disease. Despite the fact that ethanol is very close to methanol in terms of solvent toxicity, the current study identified it as the preferred solvent. Thus, the current research revisits previous studies and explores the potentiality of non-polar and polar aprotic and polar protic solvent systems, which lend credence to bioactive compounds that may be useful in isolating and formulating safe and cost effective herbal medicament for livestocks and aquaculture, and drugs for deoxygenerative human diseases, and can also be investigated further to instil environmental frugality.

Studies on

Indian minor carp Labeo bata fingerlings were reared in square shaped cages at different numbers to evaluate the effect of stocking density on growth, production and economics. Fifteen cages (5 × 5 × 2 m each) were installed in deeper areas (6–8 m) of Samaguri beel (a seasonally-flooded floodplain wetland) of Assam, India. The cages were stocked with L. bata (mean length 11.93 ± 0.20 cm; mean weight 13.05 ± 0.77 g) at five different stocking densities of 10 (SD10), 20 (SD20), 30 (SD30), 40 (SD40) and 50 (SD50) fingerlings m−3 in triplicates. Fish were fed with floating pellets containing 32% CP at 3–5% body weight twice-a-day for six months. Density-dependent growth was evident from the results as growth of fish decreased with increasing stocking densities; the specific growth rate of the fish at SD10, SD20, SD30, SD40 and SD50 were 1.03 ± 0.02, 0.88 ± 0.01, 0.84 ± 0.02, 0.67 ± 0.02 and 0.52 ± 0.01 with corresponding weight gain percent of 533.3 ± 13.41, 385.8 ± 10.73, 353.3 ± 14.17, 232.2 ± 8.08 and 155.9 ± 5.38, respectively. However, the highest net yield of fish was achieved at SD30 (50.8 kg cage−1), which was significantly higher than other stocking densities. Also, economic analysis demonstrated highest benefit-cost (B:C) ratio at 30 fish m−3 (1.44). Results indicated decreased fish yield at lower densities though the individual growth rate of fish was higher. On the other hand, fingerling stocking more than 30 fish m−3 was uneconomical because of lower individual growth rate. Hence, a stocking density of 30 fish m−3 could be considered as optimum for production of L. bata table fish in cages. The study generated new and critical information on species diversification in cage aquaculture for tropical floodplain wetlands.

The golden mahseer (Tor putitora) is an important and high valued sport and food fish of national and international importance. Therefore for promotion of golden mahseer, proper mineral supplementation in early developmental stages is very important. The present study evaluated the effects of dietary zinc on growth, survivaland physiological response of Tor putitora fry. One thousand eight hundred fry (avg.wt 54.35±3.09 mg) were randomly distributed into 6 treatment groups with triplicates each. Six iso-nitrogenous (40±0.02% to 41.44±0.01% crude protein) semi-purified diets were prepared with graded levels of dietary zinc. Zinc sulphate was added as the dietary zinc source to the basal diet. The results indicated that specific growth rate (SGR) was of value 2.52 ±0.23 gm of T. putitora fry which increased with dietary zinc levels up to a concentration of 40 mg Zn Kg-1 in diet. The zinc dependent metabolic enzymes and antioxidant enzymes was also observed to be highest in groups supplemented with 40 mg zinc/kg feed. The overall results of the present study suggest the efficacy of dietary zinc on growth, survival and physiological response of golden mahseer fry in order to garner the possibility of establishing the species to commercial aquaculture.

Length–weight relationships for six small indigenous fish species, namely: Trichogaster chuna (Hamilton, 1822), Trichogaster lalius (Hamilton, 1822), Trichogaster fasciata Bloch & Schneider, 1801, Chanda nama Hamilton, 1822, Parambassis lala (Hamilton, 1822), and Macrognathus aral (Bloch & Schneider, 1801) were studied for the first time from Deepor beel, a Ramsar site (589 ha water spread area) located in Assam, India. A total of 617 fish specimens were collected for the present study on a monthly basis from February to August in 2016 from landing centres adjoining the beel. In the present study, b value ranges from 2.778 to 3.215, which is within the normal range. The LWRs for these six fish species from Deepor beel had not yet been reported for FishBase.

An experiment was carried out to evaluate the growth performance and yield of Labeo bata reared in cages at different stocking densities in a floodplain wetland of Assam, India. Fifteen cages (effective water volume 40 m3 each) installed in the wetland were stocked with fingerlings of L. bata (mean length 8.20 ± 0.08 cm; mean weight 4.82 ± 0.13 g) at five different stocking densities, i.e., 25 (D25), 50 (D50), 75 (D75), 100 (D100) and 150 fingerlings m−3 (D150) in triplicates. Fish were fed with pelleted feed containing 30 % CP at 3–5 % body weight twice-a-day for six months. Specific growth rate of the reared fish recorded at different stocking densities were 1.08 ± 0.03, 0.89 ± 0.01, 0.90 ± 0.05, 0.77 ± 0.02 and 0.57 ± 0.02 % day-1, respectively, in D25, D50, D75, D100 and D150. The corresponding weight gain percent were 604.77 ± 35.63, 395.37 ± 11.32, 407.88 ± 44.91, 296.61 ± 13.07 and 180.70 ± 11.02. In general, growth performance of the reared fish was inversely proportional to stocking density. However, yield (biomass) increased with increase in stocking density of up to 75 fingerlings m-3 after which no significant increase was observed. Economics of the cage aquaculture system also showed highest net revenue and benefit-cost ratio at 75 fingerlings m-3. Rearing of fish at this stocking density yielded 50 % higher fish production and generated 92.5 % higher net revenue than rearing at the lowest stocking density. The results suggest 75 fingerlings m-3 as the optimum stocking density for rearing L. bata in net cages.

An in-vitro toxicity study was undertaken for the validation, laydown the standards, supplement some of the information on assessment and define the nature of toxicity of different solvent extracts of Terminalia arjuna considering Artemia salina model, as a case study. In the present study, experimental conditions such as yellow color light of 100 W at 5% salinity for 48 hours with pH 8.0-8.5 at 30 0C, picking up of nauplii with 3mL dropper cut at its tip, 24 hours incubation in same experimental conditions and visualization with 50X magnifying glass were modified unlike previous studies. Functional screening of solvent extracts with their mother solvents revealed that hex, Etac, Chlo, Acet, Etoh, and Meoh exhibited, the LC50 values as 118.50, 101.75, 93.36, 278.32, 528.78 and 477.67 ppm, respectively, designating them as; medium, medium, high, medium, low, medium toxic, while in their solvent extract forms the toxicity nature gets changed indicating the effectiveness of the extracts. Study, also defines the toxicity level for universal solvents such as DMSO and Dw as to be non-toxic as per the Meyers toxicity index and Clarkson’s toxicity criterion. Among solvent extracts of T. arjuna, all were found to be toxic as per Meyers toxicity index. However, with reference to Clarkson’s toxicity criterion, solvent extracts comprehended extended toxicity classes as low, medium and high toxic. The PCA 1 and 2 showed, 69.46% and 19.74% variations indicating strong correlation between the parameters. The results confirmed that LC50 of any solvent extract could be treated as relative LC50, which is the fraction of mother solvent and could be treated as absolute LC50, which is the actual potential of the solvent extracts that might be positive for less effective and negative for highly effective solvent extracts. For smoothening of experimental results, negative sign was ignored. Relative LC50, relative LC50%, absolute LC50, and absolute LC50% could find liner relation with their % fractions and inverse relation with their counterparts. Thus present study advocates the inclusion of relative LC50, relative LC50%, , absolute LC50, absolute LC50%, considerating 95% upper and lower fiducial class intervals and TI values while fixing the nature of toxicity and designating the safety aspect to the host. Also, the study recommends for the collective effort to make BSLA as an internationally accepted and robust standard by revisiting and supplementing the existing toxicity criterion for the BSLA.

The present study investigated traditional fishing devices namely Bundh, Dori and Gori Jal operated by fishers of Cachar District, Assam in rivers and small canals. The study was carried out in Ghagra River and adjoining small canals. Water current as well as indigenous knowledge of fishers on movement of fishes and foraging behaviour of freshwater prawns were found to be utilised to a great extent to catch the target species. Assessment of the effectiveness and rationality as perceived by fishers and experts respectively showed that Bundh fishing was highly effective Mean Perceived Effectiveness Index (MPEI score >2.5) whereas the other two fishing techniques namely Dori and Gori Jal were effective (MPEI score >2). All the three indigenous fishing techniques were found to be rational with a mean score ≥3.