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 six fish species from the headstream region of the Dongjiang River,China

Dongjiang River, a main tributary of the Pearl River, is geographically situated in South China. The present study describes the length–weight relationships (LWRs) of six fish species (Acrossocheilus paradoxus, Barbodes semifasciolatus, Onychostoma elongatum, Microphysogobio fukiensis, Microphysogobio kiatingensis, Metzia lineata) from the headstream region of the river including five Chinese endemic species (A. paradoxus, B. semifasciolatu, O. elongatum, Mi. fukiensis, Mi. kiatingensis). Fish species of five genera of the same family were collected quarterly from April 2012 to October 2014 by using non‐selective fishing gears: drag nets (5 m, mesh‐size 3 cm), drift gillnets (30 × 15 m, mesh‐size 5 mm), fish cages (4 m, mouth opening 40 × 40 cm), scoop nets (mesh‐size 0.5‐1 cm), and electro‐fishing (12V, 200 Hz). The parameter a and b in the LWR equations (W = a L^b) ranged from 0.0014 to 0.0228, and 2.89 to 3.18, respectively. Compared with FishBase, this study provides the first LWR records for four cyprinids (A. paradoxus, B. semifasciolatu, O. elongatum, Me. lineata) and a new record of maximum body length for O. elongatum.     

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 five fish species from Carangidae family in waters of the northern Persian Gulf,Iran

This research describes and presents some biological aspects of five fish species from carangidae family including: Alepes djedaba, Ulua mentalis, Alectis indica, Carangoides coeruleopinnatus, and Carangoides bajad in the Iranian waters of the northern Persian Gulf (Hormozgan Province, Iran). Samples were collected from April to September 2016. The fishing gears were gill nets (80, 100, 120 and 145 mm stretched mesh size), bottom and midwater trawls (30, 40 and 75 mm stretched mesh size in cod‐end) of local and commercial fishery. The b values of length–weight relationships ranged from 2.512 (95% CL = 0.054) for U. mentalis to 2.953 (95% CL = 0.155) for C. coeruleopinnatus and the correlation coefficient values (r²) were high for all species.     

Length‐weight relationships of three fish species from the lower Brahmaputra drainage in Assam,India

Length‐Weight relationships (LWRs) for three Cyprinids (Chela cachius, Devario devario and Securicula gora) collected seasonally from May 2016 to January 2017 along the lower Brahmaputra drainage in Assam (Northeast India), using fishing gears [cast nets: 2.5 m, 10–15 mm mesh size; gillnets: 30 × 0.9 m, 18–20 mm mesh size], were estimated. The ‘b’ values of the LWR estimates ranged from 3.39 for C.  cachius, 3.14 for D.  devario, and 2.97 for S.  gora respectively.     

Length–weight relationships of three freshwater fish species from Rupnaryan and Kangsabati River,West Bengal,India

The length–weight relationships (LWRs) of three freshwater fish species from the Kangsabati and Rupnaryan river in West Bengal, India are presented, namely as Amblypharyngodon microlepis (Bleeker, 1853), Parambassis lala (Hamilton, 1822) and Macrognathus aculeatus (Bloch, 1786). Gill‐nets (mesh sizes with 0.5 cm–4 cm), cast‐nets (up to 1 × 1 cm mesh size with up to 4.0 m² area) and scoop‐nets (0.3 × 0.3 cm and 0.5 × 0.5 cm mesh size) were used from January, 2017 to April, 2018. Sampling was done every 15 days during this period. The value of parameter “b” ranged from 2.751 to 2.895 with highly significant correlations (r² > 0.95).     

Length‐weight and length‐length relationships of three small indigenous fishes from the Payra River,southern Bangladesh

Length‐weight relationships (LWRs) and length‐length relationships (LLRs) for three small indigenous fishes (Esomus danrica, Pachypterus atherinoides and Salmostoma bacaila) were reported from the Payra River, southern Bangladesh. Samples were collected using traditional fishing gear including cast net (mesh size ranges from 1.0 to 2.0 cm), seine net (mesh size ranges from 1.5 to 2.5 cm) and square lift net (mesh size ~ 1.0 cm) in August to September 2017. Allometric coefficient (b) values were 2.66 for E. danrica, 3.08 for P. atherinoides and 3.06 for S. bacaila. The LLRs were also highly significant with r² ≥ .956.     

Length–weight relationships of seven fish species from a fish landing port at Sungai Udang,Penang, Malaysia

The length–weight relationships (LWRs) are described for seven fish species from four families (Ariidae, Clupeidae, Leiognathidae and Sciaenidae) inhabiting Penang waters. A total of 471 specimens were sampled and measured from 19 to 20 January 2015, using a bottom trawl net with a 38 mm mesh size of cod‐end. No information regarding LWRs was reported previously in FishBase for Cryptarius truncatus, Escualosa thoracata, Johnius carouna, Nuchequula blochii, Plicofollis argyropleuron, Secutor hanedai or Secutor megalolepis, and the study also provides a new FishBase record of maximum total length for Escualosa thoracata (10.6 cm), Secutor hanedai (9.1 cm) and Secutor megalolepis (7.5 cm).     

Length–weight relationships for four fish species from lower stretch of River Ganga,India

Length‐weight relationships (LWRs) for four fish species from the River Ganga (India) is presented. Sampling was conducted in the lower stretch of the river (Buxar: 25°33′43.90″N and 83°56′3.10″E to Freserganj: 21°35′40.58″N and 88°15′28.92″E) on tri‐monthly basis from September 2016 to December 2017. Specimens were caught in gill nets (mesh, 18–68 mm), cast nets (mesh, 12–14 mm), seine nets (mesh, 12–14 mm) and various traditional traps those were put over night and lifted in early morning. Total length and wet body weight of fish were measured to the nearest 0.1 cm and 0.01 g by a digital caliper and electronic balance respectively. From LWRs, the estimated b values were found to be 2.88 (Pisodonophis boro) to 3.17 (Gagata sexualis) whereas a value ranged from 0.001 (Pisodonophis boro) to 0.009 (Botia lohachata). As per FishBase, the species Gagata sexualis and Botia lohachata had new TLmax reported for LWR estimation.     

Length–weight and Length‐length relations of four fish species from the Chilika Lake,East coast of India

This study reports the length–weight relationship (LWR) and length‐length relationship (LLR) estimated for four fish species inhabiting in Chilika Lake, India. Total 504 specimens were sampled from mono‐filament gill nets (mesh size 12 mm, 22–24 mm, 34–38 mm, 42 mm) during January 2015 to December 2015. The estimated b values from LWR ranged between 2.79 (T. biaculeatus) to 3.29 (C. praeustus). In all species, the relationships between length‐weight and length‐length were highly correlated (p < .05). The study provides first world reports on LWRs and LLRs for all the 4 studied species.     

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 of three freshwater fishes from Hoiya River in South Korea

The length‐weight relationships (LWRs) for three freshwater fish species in catchment area of Hoiya River, Republic of Korea, were analyzed. Fish samples were collected quarterly using scoop‐nets (5 mm mesh size), casting nets (7 mm mesh size) from 2017 to 2018. For LWRs using the general equation from Froese (2006), the parameter b ranges from 3.14 (Oryzias latipes) to 3.37 (Iksookimia longicorpa). LWRs data of these two species have not yet been listed in FishBase.     

Length‐weight and length‐length relationships of four small fishes from the Atrai River,Dinajpur, Bangladesh

Length‐weight (LWRs) and length‐length relationships (LLRs) were determined for four fish species collected from the Atari River in Dinajpur of Bangladesh. Sampling took place monthly between January and June 2016, using seine nets of commercial fishermen (mesh size 4 mm). In LWRs (r² > .927, p < .05), slope (b) was estimated as 3.191, 2.992, 3.217 and 3.109 for Acanthocobitis botia, Botia lohachata, Canthophrys gongota and Chanda nama, respectively. In LLRs (r² > .812, p < .05), lengths i.e. TL, SL, HL and FL were highly correlated. The present study on these species would be the baseline for FishBase dataset.     

Length–weight relationship of thirteen demersal fishes from the tropical Brazilian continental shelf

This study provides the length‐weight relationship (LWR) for 13 demersal fish species belonging to 11 families and 8 orders. Data were collected in the northeast Brazilian continental shelf during two scientific surveys (2015 and 2017) using a bottom trawl net (side length of body mesh: 40 mm, side length of cod‐end mesh: 25 mm) at 35 stations between 15 and 60 m of depth. We provide novel LWRs for four species and expand the size range of 9 relationships previously established.     

Length–weight and length–length relationships of three fish species from the Yarlung Zangbo River in Tibet,China

Length–weight relationships and length–length were evaluated for three fish species (Schizopygopsis younghusbandi Regan, 1905; Ptychobarbus dipogon Regan, 1905 and Oxygymnocypris stewartii Lloyd, 1908) from the Yarlung Zangbo River in Tibet. Specimens were captured monthly using floating gillnets (mesh size 7.5 cm), bottom gillnets (mesh size 6.5 cm), and trap nets (mesh size 1.5 mm) from August 2008 to August 2009, March to August 2012, and March to April 2013. Regression coefficient (b) values of length–weight relationships (LWRs) ranged from 3.045 for P. dipogon to 3.193 for O. stewartii, whereas the a values ranged from 0.0040 to 0.0168 for O. stewartii and P. dipogon, respectively.     

Length–weight relationships of three fish species from Piediluco Lake,Italy

Length–weight relationships for Leucos aula, Scardinius hesperidicus, and Squalius squalus from the Piediluco Lake were provided. Data were collected by means of electrofishing, gill‐nets (mesh sizes varying from 5 to 55 mm) and fyke‐nets (mesh size 16 mm, total length 8 m, mouth width 1.5 m). The monitoring campaigns were carried out seasonally in the years 2004 and 2011, and in autumn 2012. A total of 5,198 specimens were analyzed. For all the species the value of b ranged between 3.163 for Leucos aula and 3.297 for S. hesperidicus. For L. aula a new maximum total length was also reported.     

Length‐weight relationships (LWRs) of four freshwater fish species from the Brahmaputra and Barak river basins,northeast India

The present study describes the length‐weight relationships (LWRs) were determined for four fish species, collected from the Brahmaputra and Barak river basins in northeast India using cast nets (2.5 × 1 m; 10–15 mm mesh size) and gillnets (30 × 0.9 m; 5–10 mm mesh size), from June 2016 to July 2017. The b values in LWRs were determined as 2.70 for Badis tuivaiei Vishwanath & Shanta, 2004, 2.93 for Canthophrys gongota (Hamilton, 1822), 2.62 for Glyptothorax botius (Hamilton, 1822), and 3.22 for Gogangra viridescens (Hamilton, 1822).     

Length–weight relationships of four marine fish species in Motaf fishing grounds,southern waters of Bushehr (the north of the Persian Gulf,Iran)

This study presents the length–weight relationships (LWRs) of four caught fish, including Drepane punctata (Linnaeus, 1758), Alectis indica (Rüppell, 1830), Argyrops spinifer (Forsskål, 1775), and Saurida tumbil (Bloch, 1795). During 27 tows, the fish specimens were captured by Cutlassfish trawl net, with 80 mm mesh size in the cod‐end, from March 2015 to April 2016. The fishing operation was conducted at depths more than 50 m in southern waters of Bushehr (the northern Persian Gulf). The estimated b values were as follow: 3.17 for D. punctata, 2.59 for Alectis indica, 2.56 for A. spinifer, and 3.26 for S. tumbil. In the present study, new maximum total lengths for D. punctata (15.2–43.5 cm), A. indica (21–69.5 cm), and A. spinifer (15.3–66.5 cm) were reported in comparison with previous researches.     

Length–weight relationships of three fish species from Bohai Sea,China

Length–weight relationships were determined for three fish species (Cynoglossus macrolepidotus (Bleeker, 1851), Liparis tanakae (Gilbert & Burke, 1912), Zoarces elongatus (Kner, 1868)) from Bohai Sea (38°38′–40°28′N; 119°42′–121°10′E), China. Fish specimens were sampled monthly between May 1982 to May 1983 using pair bottom trawlers (150.5 × 96.5 m, mesh size: 30–200 mm) with a cod end (mesh size: 30 mm), which were towed at a ship's speed of two knots for 1 hr at a maximum depth of about 80 m. Relationships between length and weight were fitted very well for all species (all R² > .90).     

Length–weight relationships of 10 freshwater fish species from an intermittent river basin,semi‐arid region,Brazil

The length–weight relationships for 10 freshwater fish species from an intermittent river basin in a semi‐arid region of Brazil were analyzed. Specimens were caught using a dragnet (3.5 × 2.5; stretched mesh size 5 mm) during running and pool phases from January to November 2015. The specimens were measured for total length and weight. Previously unavailable in FishBase, the detailed length–weight relationships of Compsura heterura, Phenacogaster calverti, and Serrapinnus piaba are reported for the first time. All fish collected presented total lengths (TL) lower than the maximum reported in FishBase.