Simanku Borah

• Doctor of Philosophy
• Scientist at Central Inland Fisheries Research Institute

The study investigates the fish community structure and environmental drivers of Deepor Beel, a floodplain wetland situated in the Brahmaputra Valley of Assam, India. Recognized as a Ramsar site of international importance, Deepor Beel is a biodiverse habitat that supports a variety of flora and fauna, including a rich ichthyofaunal diversity. This...

A phytoplankton bloom is characterized by the rapid and dense proliferation of microscopic algae within aquatic environments. This study investigated the occurrence of blooms, particularly those dominated by the genus Coscinodiscus, in the tropical Patalganga River estuary. The aim was to understand the environmental factors influencing the Coscino...

This study examined the wetland ecology, institutional frameworks, and governance mechanisms for managing self-recruiting small indigenous fishes (SIFs) across four wetlands in the lower Gangetic plain, a region bridging the Himalayan and Indo-Burma biodiversity hotspots. Using a mixed-method approach, data were gathered through semi-structured int...

The present global trade of endemic ornamental fishes is heavily relied wild-caught species that concerns long-term sustainability. This study examined the effects of dietary melatonin on the reproductive performance and health of Devario aequipinnatus (giant danio). A basal diet of 35% protein (basal diet as control) was supplemented with four dif...

Environmental characteristics significantly influence the distribution of fish communities in aquatic ecosystems. This study examined the relationship between fish community structure and ecological characteristics in the Dhansiri River, a tropical river within the Eastern Himalayan ecoregion. Sampling was conducted across three seasons (monsoon, p...

Within the regime of tropical inland fisheries, floodplain wetlands are biologically rich and sensitive ecosystems that support unique ichthyofaunal diversity and provide substantial livelihood and nutritional security to poor small-scale fishers (SSFs) in a changing climate. To protect and enhance livelihood and nutritional security, as well as to...

Phytoplankton are diverse photosynthetic organisms in estuarine ecosystems and sensitive indicators of environmental changes. This study employed Generalized Additive Model (GAM) to explore the impact of environmental variables on the abundance of six dominant phytoplankton species in the tropical Karanja estuary, India. Data were collected from fi...

This study assessed spatiotemporal water quality, hydrogeochemical characteristics, and heavy metal contamination level of anthropogenically impacted an ancient artificial freshwater wetland, Bhojtal, India, which is crucial for drinking water supply and aquatic biodiversity. The study revealed significant (p < 0.05) seasonal variations in pH, magn...

The North Eastern States (NES) are the easternmost region of India among them Arunachal Pradesh is a largest hill state and shares its international boundaries with Bhutan in the west, China in the north and Myanmar in the east with a wide range of climates and altitudes. Fish farming is playing a vital role from economic, nutritional and employmen...

Cyprinus carpio var. communis, an invasive exotic species, has been recorded for the first time as one of the most dominant species in reservoir and river-reservoir interface of Bichom, Arunachal Pradesh, India, in an investigation during May 2022–June 2023. The intensity of its invasiveness was very high, as evidenced by the relative abundance wit...

Environmental characteristics significantly influence the distribution of fish communities in aquatic ecosystems. This study examined the relationship between fish community structure and ecological characteristics in the Dhansiri River, a tropical river within the Eastern Himalaya eco-region. Sampling was conducted across three seasons (monsoon, p...

Biofilms are a crucial component of aquatic ecosystems, playing a significant role in the environment by colonizing various surfaces such as sand, rocks, and leaves. They supply energy and organic matter to the food chain, recycle organic matter, and contribute to water quality. However, biofilms can also have detrimental effects, particularly in m...

Germ cell (GC) transplantation (GCT) in teleost is widely used for surrogate gametes production and revitalization of reproductive competence in senescent fish species. Here,an innovative application of GCT is described for control of invasive fish population those compete with the native fish fauna of anecosystem. The donor GCs isolated from zebra...

This study investigated the dietary immunomodulatory effects of Terminalia arjuna bark powder (TABP) in Labeo rohita, a freshwater fish model. Four iso-nitrogenous and iso-caloric diets containing graded levels of TABP (0, 1, 10, and 15 g/kg were fed to fish for 90 days, followed by a 10 day challenge with pathogenic bacteria Aeromonas hydrophila a...

Opsarius siangi sp. nov., a previously undocumented species, has been identified from siang River, Pasighat, arunachal Pradesh, india. this newly described species is distinguished by a suite of unique morphological characteristics, notably including a complete lateral line, consisting of 65–77 scales, 32–39 pre-dorsal scales, 12–15 scales position...

The present study was conducted with the objective of developing ecologically and economically feasible pen culture protocols for Labeo catla as an alternate income source for wetland fishers in the context of the COVID-19 pandemic. Yearlings of L. catla (12.33 ± 1.99 cm mean total length and 26.05 ± 6.57 g mean weight) were reared in HDPE pens (50...

Gandak is a transboundary Himalayan tributary of the Ganga River system. The fish diversity of this important Gangetic River was studied during 2014–2016. A total of 75 fish species were recorded during the survey, of which 52 species were indigenous small fishes (ISFs) belonging to 18 families, and the rest 23 species were non-ISFs. Family-wise sp...

India is blessed with 0.5 million ha of floodplain wetland resources largely distributed in northern, eastern and northeastern region of the country. Floodplain wetlands in have been recognized as one of the important fishery resources in the Northeast India, both in terms of resource size (1,44,513 ha) and production potential. These resources con...

The current study used phytoplankton functional groups (FGs) to assess the impact of barrages on the ecological function of subtropical river Ganga. A total of 101 phytoplankton species were identified, including 20 phytoplankton FGs with MP and D having the highest prevalence rates of more than 50%. Other FGs with higher occurrence rates, such as...

The Hilsa, Tenualosa ilisha, commands a very high value as food fish. The present study was carried out to understand the breeding phenology of T. ilisha in relation to climatic variables. Monthly fish samples were collected from two landing centres, namely, Uzanbazar (Guwahati) and Shri Ramghat, Dhubri, of River Brahmaputra during May 2018 to Apri...

In India, the area under reservoir fisheries was estimated at about 4.03 million ha with over14,000 reservoirs. The area of small reservoirs(<1000 ha) is around 1.78 million ha and that under medium (1000-5000 ha) and large reservoirs (> 5000 ha) in India is estimated to be 2.25 million ha. There are a total of 20 small reservoirs in 8 states of NE...

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 p...

The present study discussed the food and feeding habits of Ailia coila from Brahmaputra River, India, for the first time. Based on index of preponderance (IP) values—aquatic insects (93.87%), zooplankton (2.28%), and eggs (cladoceran and copepod) (1.62%) were found to be major food components. Insect Potamanthus sp. comprised 90–97% of gut contents...

Simple Summary It is widely believed that aquaculture has the greatest potential to provide both economic and nutritional security. Bacterial infections in the culture system result from intensified aquaculture methods, resulting in a significant economic loss for fishermen. Because antibiotics are the standard treatment for bacterial infections in...

Tenualosa ilisha, commonly called Hilsa, is a highly prized species, which has declined in River Brahmaputra, India. The study was carried out for one year and a total of 1,026 individuals were sampled at monthly intervals. In the study, the following growth parameters were observed: asymptotic length (L∞) = 445 mm, growth coefficient (K) = 0.5 yea...

Aeromonas species exhibit widespread presence in food, poultry, and aquaculture. They are major multi-drug-resistant fish pathogens. This study aims to identify Aeromonas species harbouring virulence genes aerolysin, flagellin, and lipase from diseased fishes of Assam wetlands with association with antibiotic resistance and in vivo pathogenicity. O...

Assam has rich and diverse fisheries resources in the form of rivers, floodplain wetlands, forest fisheries, ponds, etc. and endowed with rich fish diversity. Total fish production of Assam in 2021-22 was 4,17,000 MT. During 2019-20, the state ranked 12th in terms of overall fish production and 7th in inland fish production in the country. The stat...

Circular bio-economy of biogenic resources designates the plunging use of such resources, adopting a systemically formatted pathway towards sustainable economic development. Aquaculture has been perceived to play a pivotal role in supplying protein and mineral rich organic food to a growing human population. The exponential growth of aquaculture se...

Asian leaf fish Nandus nandus (Hamilton, 1822) is a valued small indigenous freshwater fish (SIF) in inland waters with high food, and conservation importance but relatively less studied. We assessed the impact of regional climate variability for the first time on population attributes and breeding phenology and predicted its biological vulnerabili...

Analysis of long-term (1987-2019) fish landing data showed that an average 191.93 t year-1 of fish landed at Uzanbazar (Guwahati) landing center of River Brahmaputra. The total landings registered peak landings of 471.8 t in 2002 and thereafter it declined to the lowest levels of 84.06 t in 2016. Fish landings suffered changes in the qualitative an...

Tenualosa ilisha, commonly called Hilsa, is a highly prized species, which has declined in River Brahmaputra, India. The study was carried out for one year and a total of 1,026 individuals were sampled at monthly intervals. In the study, the following growth parameters were observed: asymptotic length (L∞) = 445 mm, growth coefficient (K) = 0.5 yea...

Floodplain wetlands located in Ganga-Brahmaputra basin are some of the major inland fisheries resources of India with substantial resource size of 554,213 ha. These resources are amenable to capture fisheries and fisheries enhancement. The has developed protocols for scientific fish stock enhancement (through supplementary stocking) for floodplain...

Fish fauna of Dighali beel, upper Brahmaputra basin, India was comprised of 40 species belonging to 10 orders and 21 families. Families Cyprinidae and Danioni�dae dominated the species encountered, accounting for 30% of the total. Shannon, Simpson, Margalef, Menhinick, and Pielou indices were in range of 2.095–2.895, 0.851–0.928, 2.196–5.402, 1.129...

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...

The floodplain wetlands are amenable to different forms of enhancement options including culture-based fisheries (CBF). Fish production potential of this system is very high, but realized average actual production is still on the lower side. This reflects unscientific and poor management of resources. Therefore, on-field studies were carried out in...

The assemblage pattern of macrobenthic invertebrates concerning environmental variables on a spatiotemporal scale from river Tamas, a tributary of river Ganga was studied during the period 2017–2019. Altogether 27 genera of Gastropoda (10), Bivalvia (7), Insecta (7), and Annelida (3) belonging to 15 families, and 9 orders were recorded across six s...

Present study is the first attempt to assess effectiveness of supplementary stocking of the fingerlings of Indian major and minor carps on fish yield, per capita fish production and fishers’ income and analysis of relationship between stocking density versus yield and yield versus water area in floodplain wetlands of North Eastern India. Data on cu...

Food and feeding habits of Tenualosa ilisha collected from two sampling locations in Brahmaputra River, Assam, India for a period of 12 months from May 2018 to April 2019 were studied. Index of preponderance revealed semi-digested animal matter (25.92 %) as the most dominant food item followed by Bacillariophyta (23.32 %). 31 genera of phytoplankto...

Charan beel is a closed floodplain wetland located in Baksa district, Assam. Culture-based fisheries (CBF) and pen culture demonstrated in the beel to enhance fish production and income of tribal fishers in a participatory mode. For CBF, advanced carp fingerlings @ 3,000 no. ha-1 were stocked in the beel in December, 2020. CIFRIHDPE pens were also...

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 has further aggravated the problem of eutrophication causing wa...

Culture-based fisheries and pen culture technologies demonstrated in Bamuni beel, Assam through community participation to support income and livelihood of local tribal fishers. Little or no supplementary stocking was practiced in the beel, resulting in low fish production and modest net annual income to the community members during 2019-20. Advanc...

Fisheries enhancement through pen culture of Indian major carp Labeo catla for small scale beel fishers of NE region, India during COVID pandemic: A regional study

Delineating stock structure of Indian Shad, Tenualosa ilisha from Indian part of Brahmaputra using holistic approach for sustainable management

Understanding breeding phenology of Tenualosa ilisha and role of climatic variables in a tropical river

Umiam reservoir (25°39'30'' N and 91°43'51''E) is a small reservoir (water spread area 500 ha) located in Ri-Bhoi district in Khasi hills region of Meghalaya at an altitude of 900 m above mean sea level. There is no organized fishery in this reservoir and is an open-access capture fishery. Subsistence fishing and limited commercial fishing (using g...

Deepor Beel is a prominent floodplain wetland and a Ramsar site of northeastern (NE) India (Ramsar site no. 1207) covering a 40.14 km2 area and connected to River Brahmaputra. It provides numerous economic (e.g., livelihood and nutritional security) and ecological benefits (e.g. moderation of floods, groundwater recharge, repository of biodiversity...

Floodplain wetlands located in Ganga-Brahmaputra basin are some of the major inland fisheries resources of India with substantial resource size of 554,213 ha. These resources are amenable to capture fisheries and fisheries enhancement. The Guwahati Regional Centre of Indian Council of Agricultural Research-Central Institute of Fisheries Research In...

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 wa...

For effective fisheries management of Brahmaputra River in Assam, India as well as for sustainable fishery development in the river stretch, it is significant to know the change in pattern of fish landings in previous years. Statistical modelling helps in describing the dynamics of fish landings and their short-term predictions. Thus, we attempted...

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 wi...

Abstract 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 redu...

Deepor Beel is a prominent floodplain wetland and a Ramsar site of northeastern (NE) India (Ramsar site no. 1207) covering a 40.14 km 2 area and connected to River Brahmaputra. It provides numerous economic (e.g., livelihood and nutritional security) and ecological benefits (e.g. moderation of floods, groundwater recharge, repository of biodiversit...

The present study was an attempt to perform functional screening and evaluating the effects of solvent extracts of Terminalia arjuna against Argulus bengalensis. Solvent extracts were used at 10, 20, 30, 40, and 50 mg/L, at 1, 2, 3, 4 and 5 hours and 12, 24, 36,48 and 60 hours under in-vitro and in-vivo conditions, respectively in moderately parasi...

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 m 3 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)...

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 status and biota, and harbor around 96 fish species, however the fish diversity is declining in recent years due to anthropogenic and other stressors i...

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 status and biota, and harbor around 96 fish species, however the fish diversity is declining in recent years due to anthropogenic and other stressors in...

The migratory tropical shad, Tenualosa ilisha has a wide range of habitat preferences like rivers, reservoirs, estuaries, backwaters, and coastal waters during different phases of its life cycle. The present study investigates morphological variations among three populations of Hilsa from distinct ecosystems such as the River Brahmaputra, Narmada e...

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...

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...

On the population characteristics of anadromous Hilsa shad tenualosa ilisha (Hamilton, 1822) in a tropical river, Brahmaputra.

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...

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...

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 b...

Studies were carried out from April 2016 to March 2017 for effective understanding of diversity combined with environment-influenced spatiotemporal dynamics of microfloral structure in Kailash Khal wetland of Indian Sundarbans. A total of 36 phytoplankton genera were recorded from the study area. Eight major algal groups were in order of: Bacillari...

An attempt was made to establish association pattern between dimension of fish and otolith to expedite morphometric variations of geographically isolated stocks of Tenualosa ilisha (Hamilton, 1822), from three diverse ecosystems; viz., an estuarine (brackish water), a riverine (freshwater) and a lacustrine (freshwater) ecosystem. Sampling was carri...

The present paper describes ITK associated with a unique indigenous fishing method used to catch mud-dwelling spiny eels (Macrognathus spp.) in floodplain wetlands of Assam by Bhatiya community in Lower Assam (locally called Akra mara) as well as by the Mising tribe in Upper Assam (Germe-Kenane). Here the spiny eels are caught by piercing them with...

Longphongtook an indigenous fish aggregating method practised along the Namsang stream by Nocte tribe of Tirap district of Arunachal Pradesh has been described in the present study. In this practice, fishes were caught by attracting them to a circular structure (diameter 2.5 to 2.75 m) made up of boulders and pebbles of the river bed. The study rev...

The present study was carried out to establish the relationship between total length (TL) and total body weight (BW) and relationship between total length (TL), standard length (SL) and fork length (FL) for two native fish species from Kolong river, Nagaon, Assam, India. A total of 676 specimens comprising Mystus cavasius (n=285) and Cirrhinus reba...

Besides Agriculture, Fish farming is one of the main occupations in the North-Eastern state of Assam. 10.5% of the geographical area is occupied by surface water bodies, in which 6503 sq km is held by the river systems including the mighty Brahmaputra and 1748 sq km by natural wetlands including seasonal and permanent waterlogged, marshy areas and...

The present article focusses on Amblyphoryngodon mola, a candidate fish for species enhancement in beels (floodplain wetlands) of Assam, India. A brief description of the biology of this fish species and a case study of species enhancement programme with A. molo in a floodplain wetland are also being incorporated. A. mala with a very short food cha...

In the present study ornamental fish diversity in the Jiadhal/Kumotiya river of Dhemaji district, Assam, India was conducted during monsoon period from May 2018 to July 2018. A total of 44 species was recorded during the period of the study which belonging to 28 genera, 20 families and 9 orders. Highest species recorded from Cyprinidae family. The...

The present study was carried out in the upper stretch of Jenam river, a tributary of River Barak, which flows through Dima Hasao district of Assam. Conventional fishing gears are not found to be very effective in fast flowing hill streams. Therefore, the local inhabitants of such areas generally use many traditional fish catching devices suitable...

An indigenous fishing technique practised in River Brahmaputra and two of its north bank tributaries namely Bhelengi and Chaulkhowa in Barpeta district of Lower Brahmaputra valley, Assam is described here. This particular fishing method involves catching of a predatory freshwater fish species Wallago attu (Bloch & Schneider, 1801) using Salmophasia...

The present study was conducted in 13 earthen ponds measuring 0.1 ha for 3 months to study the efficacy of different doses of pig dung i.e. 4,000 kg ha-1 , 6,000 kg ha-1 , 8,000 kg ha-1 and 10,000 kg ha-1 on growth performance and survival of Indian major carps. Supplementary feed was used twice daily @ 3% body weight per day for entire experiment....

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...

Ten indigenous freshwater fish species belonging to nine genera and seven families were collected from Gandak River, Bihar, India during December, 2014 to September, 2016. Fishes were caught using Cast nets, Gill nets, Drag nets with mesh size of 15–20 mm, 25–30 mm and 5–10 mm respectively along with Traps. Sampling was done during dry and wet seas...

Quality stocking material is required for fish stock enhancement in seasonally open beels. To fulfill this, a pen aquacultureexperiment was undertaken in a moderate-sized (20 ha) seasonally open floodplain wetland of Assam (Mer beel, Nagaon district) to produce stunted carp fingerlings. Four big-sized (2500 m2 each) rectangular penswere constructed...