Length–weight relationships of Barilius bendelisis (Hamilton, 1807), Barilius shacra (Hamilton, 1822) and Barilius barna (Hamilton, 1822) from Manas River in Assam,India

The present study describes the length–weight relationships (LWRs) for three ornamental hill stream fish species from the Manas River in Assam, India, namely, Barilius bendelisis (Hamilton, 1807), Barilius shacra (Hamilton, 1822), and Barilius barna (Hamilton, 1822). Fishes were collected on a monthly basis from March 2015 to February 2016 with cast nets (270 cm, 1.2 cm) and gillnets (7,500 × 130 cm, 5 cm). This is the first information on LWR data for two of the species.     

Length–weight relationships of wild and farmed Tor putitora from Pakistan

Length–weight relationships (W = a TL^b) were estimated for wild and farmed Tor putitora obtained from River Korang, Islamabad and Attock District, Pakistan, respectively. The results indicate, W = 0.0171 TL^2.85 for wild and W = 0.1000 TL^2.33 for farmed. Total length ranged from 18.0 to 40.2 cm for male and 31.6 to 37.0 cm for female wild Tor putitora, indicating that the fish are now much smaller. The first reference of length–weight relationships for Tor putitora is provided.     

Length–weight relationships of Hara hara (Hamilton, 1822), Pangio pangia (Hamilton, 1822) and Setipinna brevifilis (Valenciennes, 1848) from the lower Brahmaputra River,Northeast India

The present study describes the length–weight relationships (LWRs) for Hara hara, Pangio pangia and Setipinna brevifilis from the lower Brahmaputra River in Assam, Northeast India, collected from June 2016 to May 2017, using fishing gears namely cast nets (9′, 1 ⁄ 2″) and gillnets (30 × 0.9 m). No previous data have ever been recorded on LWR for these three species.     

Length‐weight relationship and reproductive parameters of Botia dario (Hamilton, 1822) in Assam,India

The length‐weight relationships, spawning season, sex ratio, size at first maturity and fecundity of Botia dario (Hamilton, 1822), also known as the Bengal loach, were analyzed based on 556 specimens collected from the wetlands of Majuli Island, Assam between June 2012 and May 2013. The sex ratio (M : F) was 1 : 0.68, differing significantly (P < 0.05) from a 1 : 1 ratio. Size at first maturity (L_m50) was estimated as 6.8 cm for males and 7.4 cm for females. Analysis of monthly variations in the gonado‐somatic index (GSI), the monthly proportions of macroscopic gonadal maturity, and the ova diameter suggest a prolonged spawning season of B. dario from May to August, with a peak in July for both males and females (GSI = 15.0 in females; 7.0 in males). Absolute fecundity varied from 2523 to 51 377, with a mean of 18 367 ± 1254 oocytes per ovary. A positive correlation was recorded between total fecundity and body weight (r² = 0.678).     

Distributional records of Tor mahseer Tor tor (Hamilton, 1822) from Southern India

During exploratory surveys in the tributaries (Penganga and Satnala) of Godavari and (Bheema) Krishna basins, specimens of mahseer were collected. The morpho‐meristic characteristics of these specimens conformed to the taxonomic keys for Tor tor. The mitochondrial COI sequences of these specimens clustered with the T. tor specimens from the River Narmada and were distinct from the other mahseer such as T. khudree and T. mussullah, which are known to exist in the rivers of the region. This confirmed the distribution of T. tor in the rivers of peninsular India and indicated an extended distribution of the known range. The major predominating habitat characteristics of collection areas were cobbles mixed with gravel, and a riparian cover of shrubs and trees. The occurrence of fingerling size specimens in the river suggests that the species has adapted and is likely to have established self‐recruiting populations in these rivers.     

Length–weight relationship of clown knifefish Chitala chitala (Hamilton 1822) from the River Ganga basin, India

This study describes the length–weight relationship (LWR) of the clown knifefish, Chitala chitala, in the River Ganga basin, India. A total of 221 specimens ranging from 31 to 120 cm total length (TL) and 550 to 12 000 g total weight (TW) were collected. Chitala chitala constitutes an important component of riverine fisheries of India and is considered one of the most commercially important and highly priced foods in addition to being an aquarium fish. The species has recently undergone heavy fishing pressure, leading to an alarming decline in natural populations and deserving of high conservation importance. Length–weight relationships of C. chitala from wild populations had not yet been studied. Hence, the study objective was to evaluate length–weight relations of C. chitala from eleven populations in order to help in conservation and management of the riverine population.     

Length–weight relationships of Garra birostris Nebeshwar & Vishwanath, 2013, Garra annandalei (Hora, 1921), Johnius coitor (Hamilton, 1822) and Raiamas bola (Hamilton, 1822) from the Brahmaputra River basin,Northeast India

Length–weight relationships (LWRs) for one percoid (Johnius coitor) and three cyprinid (Garra birostris, Garra annandalei and Raiamas bola) fish species from the Brahmaputra River basin in Assam, Northeast India, was studied on a monthly basis from November 2015 to December 2016, using fishing gears namely, cast nets (9′, 1/2″) and gillnets (30 × 0.9 m). No previous record is available on LWR data for three of these species.     

Length‐weight relationships of Barilius barila (Hamilton, 1822), Opsarius tileo (Hamilton, 1822) and Cyprinion semiplotum (McClelland, 1839) collected from Manas River in Assam,India

Length‐weight relationships (LWRs) are presented for three hill stream fish species belonging to the family Cyprinidae namely, Barilius barila (Hamilton, 1822), Opsarius tileo (Hamilton, 1822) and Cyprinion semiplotum (McClelland, 1839). Fishes were collected on a monthly basis from January 2016 to December 2017 with the help of cast net (270 cm length, 1.2 cm mesh size) and gillnet (7,500 cm length × 130 cm depth, 5 cm mesh size) from the Manas river in Assam, India.. A new length record for the FishBase LWR database was observed in B. barila.      

Length–weight relationships of 10 fish species from a Ganga River Basin tributary,Uttarakhand, India

Length‐weight relationships (LWRs) are described for 10 fish species belonging to three families from the Gaula River, a tributary of the Ganga River Basin in India. LWRs for these species were unknown to FishBase, and new maximum lengths are recorded for one species. These results will be useful for fishery research, management and conservation in the least‐explored tributary of the Ganga River Basin.     

Length–weight relationships of two cyprinid fish species,Crossocheilus latius (Hamilton, 1822) and Garra gotyla gotyla (Gray, 1830) from the Ganga River Basin,India

This study provides length–weight relationship (LWR) information for two fish species (family Cyprinidae), Crossocheilus latius (Hamilton, 1822) and Garra gotyla gotyla (Gray, 1830), from a tributary of the Ganga River Basin, India. Both species had no previous LWR estimates as per Fishbase 2014.     

Length–weight and length–length relationship of Thryssa purava (Hamilton, 1822), Thryssa polybranchialis Wongratana, 1983 and Thryssa mystax (Bloch & Schneider, 1801) from Chilika lagoon,India

Current study provides basic information on Length–weight relationship (LWR) and length‐length relationship (LLR) of three fish species of genus Thryssa (Clupeiformes: Engraulidae) i.e., Thryssa purava (Hamilton, 1822), Thryssa polybranchialis Wongratana, 1983 and Thryssa mystax (Bloch & Schneider, 1801) from Chilika Lagoon, India. Samples were collected during the monsoon (July) and post‐monsoon (November) seasons in 2016 and during the pre‐monsoon season (May) in 2017, using screen barrier nets (mesh size 8–18 mm) and gill nets (mesh size 14 and 16 mm). The b values were determined from LWRs as 3.026 for Thryssa purava, 3.326 for Thryssa polybranchialis and 3.081 for Thryssa mystax.     

Length–weight relationships of some fish from the Ganga River,India

Length–weight relationships (LWRs) were determined for seven riverine fish species from the river Ganga, India. Specimens were collected on a bi‐monthly basis from April 2017 to December 2018 using gill nets (mesh size 22–34 mm), cast nets (mesh size 16 mm) and bag nets (mesh size 14–22 mm). Total length was measured to the nearest 0.1 cm using a digital caliper and weight was recorded to the nearest 0.01 g on an electronic balance. From estimated length–weight relationships, the values for parameter “a” ranged from 0.004 (Bregmaceros mcclellandi and Setipinna tenuifilis) to 0.014 (Brachirus pan). Likewise, the values for the parameter “b” of the equation ranged from 2.958 (Bagarius bagarius) to 3.124 (Bregmaceros mcclellandi) and r² from 0.978 (Gonialosa manmina) to 0.996 (Brachirus pan).     

Length–weight relationships for Eutropiichthys murius (Hamilton, 1822), Coilia reynaldi Valenciennes, 1848 and Johnius gangeticus Talwar, 1991 from lower stretch of the River Ganga,India

Length‐weight relationships (LWRs) for three fish species from the River Ganga (India) is presented. Sampling was conducted from the lower stretch of the River Ganga (Patna: 25°36′51.66″N & 85°12′7.02″E to Freserganj: 21°35′40.58″N & 88°15′28.92″E) during April, June and September and December of 2017. Specimens were caught using gill nets (18 nos.; mesh 18–32 mm), and bag nets (3 nos.; mesh 14–22 mm). The values a and b from LWRs ‐were found to be 0.007 and 2.977 for Eutropiichthys murius; 0.003 and 3.001 for Coilia reynaldi; 0.009 and 3.010 for Johnius gangeticus.     

Length–weight relationships of Dermogenys pusilla Kuhl & van Hasselt, 1823 (Zenarchopteridae) and Labeo bata (Hamilton, 1822) (Cyprinidae) from the Ganges River (NW Bangladesh)

Length‐weight relationships (LWRs) were determined for Dermogenys pusilla (n = 75) and Labeo bata (n = 304) from the Ganges River, northwestern Bangladesh, collected between July 2013 and June 2014, using traditional fishing gear (e.g. cast net, square lift net and gill net). Total length (TL) was measured to 0.1 cm and whole body weight (BW) was taken to the nearest 0.1 g for each individual. The TL varied from 6.60 to 16.10 cm for D. pusilla and 7.90–25.20 cm for L. bata. The BW ranged from 1.20 to 10.90 g for D. pusilla and 4.70–167.30 g for L. bata. All LWRs were highly significant (P < 0.001), with all r² values ≥0.976. Moreover, the present study provides a new record of the maximum length (16.10 cm TL) for the D. pusilla female. The present study can assist in the management of these two endangered species in the Ganges River ecosystem.     

Length–weight relationship of 37 fish species from the Taquari River (Paranapanema Basin,Brazil)

This work describes the length–weight relationship (LWR) of 37 fish species from the Taquari River, one of the tributaries of the Jurumirim Reservoir in the high Paranapanema Basin, São Paulo, Brazil. Information was not yet available in FishBase on LWRs of 22 of the fish species and maximum weights (Wt) of 24 of the fish species. New maximum standard lengths are presented for nine species as well as weights for two fish species.     

Length–weight relationship of three fish species from the Qiantang River,China

Length–weight relationships (LWRs) of the three fish species, Pseudobagrus albomarginatus(Rendahl, 1928), Pseudobagrus crassilabris (Günther, 1864), and Rhinogobius davidi(Sauvage & Dabry de Thiersant, 1874), were determined respectively. Samples were collected from Qiantang River, China during March 2016–December 2017. The bvalues ranged from 2.525 to 2.917, the coefficient of determination (r²) ranged from 0.96 to 0.97. Prior to this study, the length–weight relationship for P. albomarginatus and R. davidi were unknown to FishBase and the new maximum total lengths for three species were not recorded in FishBase. These results are useful for the fishery research and management in Qiantang River.     

Condition factor,length–weight and length–length relationships of an endangered fish Ompok pabda (Hamilton 1822) (Siluriformes: Siluridae) from the River Gomti,a tributary of the River Ganga,India

The present study describes the condition factor, length‐weight and length‐length relationships for an endangered freshwater fish species Ompok pabda (Hamilton) of the family Siluridae from the River Gomti in Northern India. The values of regression parameter b ranged from 2.81 to 3.32 (r² > 0.90). During the pre‐monsoon, the allometric coefficient b of the LWR was close to isometric value (b = 3.08) allometric (b = 2.87), although it suggested negative allometric growth in monsoon periods while positive growth in post‐monsoon. The condition factor values ranged from 0.672 to 0.744. Results of the present study could be useful to help in conservation and sustainable fisheries management of this endangered species.     

Length weight relationships of two small indigenous cyprinid fishes,Osteobrama cotio (Hamilton, 1822) and Salmophasia phulo (Hamilton, 1822) from Panchet Reservoir,Damodar River (tributary of River Ganga), India

Length–weight relationships were determined for two small indigenous cyprinid fishes: Osteobrama cotio (Hamilton, 1822) and Salmophasia phulo (Hamilton, 1822) collected from Panchet reservoir, Damodar River, India. About 143 specimens of Osteobrama cotio (5.2–10.4 cm TL) and 113 specimens of Salmophasia phulo (2.9–8.2 cm TL) were collected from November 2014 to June 2016 using gillnets of mesh size ranging from 25 to 120 mm (STR) and dragnets of mesh size 10–20 mm (STR). No previous information on LWRs for these two species from an Indian reservoir was available in the literature.     

Analysis of length‐weight relationship of sympatric hill stream teleosts Barilius bendelisis (Hamilton, 1807) and Barilius vagra (Hamilton, 1822) from Garhwal Himalaya,India

The present study describes the length–weight relationships (LWRs) of two important ornamental hill stream fishes, Barilius bendelisis and Barilius vagra (Hamilton), of northern India. A total of 630 specimens were collected from January to June 2011 in a spring‐fed stream in Garhwal Himalaya, India. Information regarding LWRs of these species was not yet available in FishBase.