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 relationships for five freshwater fish species from the Utinga State Park,Northeast Amazon,Brazil

Length–weight relationships (LWR) were estimated for five most abundant fish species occurring in the Utinga State Park within the metropolitan area of Belém, State of Pará, Northern Brazil. Data were obtained from specimens of Curimata knerii (n = 75), Gasteropelecus levis (n = 54), Hemigrammus rodwayi (n = 82), Hyphessobrycon bentosi (n = 69), and Pristobrycon calmoni (n = 76) collected in July 2013 with seines (1.5 mm mesh), sieves (1 mm mesh), and gill nets (40–120 mm mesh) in the main waterbodies. All LWRs are novel for science, increasing knowledge on biological information of the Neotropical freshwater fish.     

Length‐weight relationship of two Ambassid fish species,Parambassis dayi (Bleeker, 1874) and Parambassis thomassi (Day, 1870) from River Pamba,Southern Western Ghats,India

The present study provides the length‐weight relationships (LWRs) of two Ambassid fish species, Parambassis dayi (Bleeker, 1874) and Parambassis thomassi (Day, 1870) from River Pamba in Southern Western Ghats, India. Fishes were collected on a monthly basis between April 2014 to March 2015 using gill nets (1.0–3.0 cm), cast nets (1.0–2.0 cm) and seine nets (1.0 cm). The b values in the LWRs were estimated as 3.01 for P. dayi and 3.14 for P. thomassi. No previous information is available on LWRs for these two species in FishBase.     

Length‐weight relationships of three cyprinid fish species from southwestern China

Length–weight relationships (LWRs) were determined for three cyprinid fish species [Acrossocheilus yunnanensis (Regan, 1904), Onychostoma simum (Sauvage & Dabry de Thiersant, 1874) and Spinibarbus sinensis (Bleeker, 1871)] from southwestern China. Samples were obtained with various fishing gear (set nets, drift gill nets, fish cages, hook and electrofishing). Prior to this study, the LWRs for these three species (A. yunnanensis, O. simum and S. sinensis) were unknown.     

Length‐weight relationships of two cyprinid fishes from the Beijiang River,Guangdong, China

This study reports the length‐weight relationships (LWRs) of Acrossocheilus beijiangensis Wu & Lin, 1977 and Barbodes semifasciolatus (Günther, 1868) from the upper reaches of Beijiang River, Guangdong Province, China. Sample sizes for the two fish species were 335 for A. beijiangensis and 106 for B. semifasciolatus. Fishes were collected on a monthly basis between November 2013 and December 2014 using gill nets (30 m long × 1.2 m high, mesh‐size 1.5 cm) and fish cages (mesh‐size 0.5 cm). LWRs were established as W = 0.0052L^3.3249 (r² = .9696) for A. beijiangensis and W = 0.0088L^3.2405 (r² = .9469) for B. semifasciolatus. No previous information is available on LWRs for these two species in FishBase.     

Length–weight relationships of three Gobiidae species from the Rupsha River in southwestern Bangladesh

This study reports the length–weight relationships (LWRs) of three Gobiidae fish species (Acentrogobius viridipunctatus, Apocryptes bato, and Odontamblyopus rubicundus) from the Rupsha River, southwestern Bangladesh. A total of 388 individuals were sampled using cast nets (mesh size ranges from 1.5 to 3.0 cm), gill nets (mesh size ranges from 2.0 to 3.0 cm) and square lift nets (mesh size ~1.5 cm) from December 2014 to November 2015. Allometric coefficient (b) values were 3.23 for A. viridipunctatus, 2.70 for A. bato, and 2.67 for O. rubicundus, respectively. The first LWRs records for these three Gobiidae species, they can be used online for FishBase as well as in future studies.     

Length‐weight relationships for three fish species from the coastal waters of the northern Yellow Sea,China

Length–weight relationships (LWRs) were determined for three fish species: Thamnaconus modestus(Günther, 1877), Callionymus beniteguri  ( Jordan & Snyder, 1900) and Takifugu rubripes (Temminck & Schlegel, 1850), collected from the coastal waters of the northern Yellow Sea (near Dalian City) using bottom trawl nets in October 2017 and set nets in April 2018. Parameter b values in the fitted LWRs were 3.367(T. modestus), 2.817(C. beniteguri) and 3.200 (T. rubripes), respectively.     

Length‐weight relationships for nine fishes in the Nujiang River,Southwest of China

Length‐weight relationships (LWRs) were determined for nine fish species occurring in the Nujiang River. Fish were collected using gill nets, including two nets of 1.0 m depth (100 m long; mesh size 0.5 cm), two nets of 1.0 m depth (150 m long; mesh size 2.0 cm) and two nets reaching 1.5 m depth (mesh size 6.0 cm). Gill nets were set over night including different habitats (riffles and pools, vegetated and non vegetated zones) from four sections in July of the following 2 years: 2004 and 2008. The LWRs presented here include for all nine studied species (Pseudexostoma brachysoma Chu, 1979, Creteuchiloglanis gongshanensis [Chu, 1981], Glyptothorax zanaensis Wu, He & Chu, 1981, Glyptothorax dorsalis Vinciguerra, 1890, and Glyptothorax trilineatus Blyth, 1860, Schizothorax gongshanensis Tsao, 1964, Schizothorax meridionalis Tsao, 1964, Placocheilus cryptonemus Cui & Li, 1984, and Schistura longa [Zhu, 1982]), and new maximum standard length of four species not yet reported in the literature.     

Length–weight relationships for estuarine fishes in South Brazil

The present study reports the length‐weight relationships (LWRs) for 18 estuarine species sampled in Guaratuba Bay, South Brazil. For the majority of these 18 species the LWRs are known from the literature, but these estimates do not consider sexes separately which is done in this contribution. Different fishing gears were used in the samplings (cylindrical nets – 1 mm mesh size, bottom trawls – 250 mm mesh size in the arms and 12 mm mesh size in the bag, beach seine – 5 mm mesh size and hook and line fishery) between September 2007 to April 2014. The specimens were sexed and the LWRs were calculated for each sex separately. There were differences between sexes in growth type, showing the importance of sexing in these studies. We reported for the first time (based on FishBase) the LWRs for two species: Ctenogobius shufeldti and Hypleurochilus fissicornis.     

Length‐weight relationships for three fishes in the Mali Hka River and Nmai Hka River,Myanmar

Length‐weight relationships (LWRs) were investigated for three fish species occurring in the Mali Hka River and Nmai Hka River. Fish were collected monthly from five sites between January and May 2009, using gill nets in the main river and electrofishing in tributaries (gill nets of three types: (a) = 10 m long, 0.5 m depth, 0.5 cm mesh size); (b) = 15 m long, 1 m depth, 2.0 cm mesh size; and (c) = 20 m long, 1.5 m depth, 6.0 cm mesh size. Soaking time for all was 24 hr). The LWRs for Botia histrionica Blyth, 1860, Crossocheilus burmanicus Hora, 1936 and Schizothorax grahami (Regan, 1904) are given in Table 1 along with the appropriate statistics for the parameters a and b of the equation as well as the confidence intervals and the correlation coefficient. All values of parameter b ranging from 2.57 for Botia histrionica Blyth, 1860 and 3.19 for Crossocheilus burmanicus Hora, 1936 (in all cases r² > 0.96). A new total length has been recorded for Schizothorax grahami (Regan, 1904) when comparing with records given in the international electronic databank FishBase (Froese & Pauly, 2018).     

Length‐weight relationships of three fish species from the coastal waters of Yellow Sea,China

Length–weight relationships (LWRs) were determined for three fish species: Zebrias zebrinus (Temminck & Schlegel, 1846), Setipinna termuifilis (Valenciennes, 1848) and Pampus echinogaster (Basilewsky, 1855). Samples were collected from the coastal waters of Yellow Sea, China, from early April to mid–April 2017 using bottom trawl nets (20 mm stretched mesh size of cod‐end) and set nets (15.6 mesh size). The values of exponent b in the fitted LWRs ranged from 3.101 to 3.427 for three fish species.     

Length–weight and length–length relationships of five fish species in the Atrai River,Dinajpur, Bangladesh

A total of 502 specimens were obtained during monthly samplings from July to December 2015, by fishermen using seine nets, gillnets and cast nets. Length–weight (LWRs) and length–length (LLRs) relationships were estimated for five fish species collected from the Atrai River in the northwestern region of Bangladesh. The values of slope (b) in LWRs (r² > .913, p < .001) were determined as 2.899 for Aspidoparia jaya, 3.059 for Gagata cenia, 3.004 for Gagata youssoufi, 2.755 for Salmophasia bacaila, and 3.222 for Salmophasia phulo, respectively. The linear relationships in TL, FL and SL were highly correlated (for all cases: r² > .897, p < .001). No previous information on LWRs (except for G. cenia) and LLRs (except for S. bacaila) of these selected species were found in FishBase.     

Length‐weight and length‐length relationships of Balitora brucei Gray, 1830 and Psilorhynchus balitora (Hamilton, 1822) from the Ranganadi river of Assam,India

The study describes length‐weight relationships (LWRs) and length‐length relationships (LLRs) for two species of fishes, namely Balitora brucei Gray, 1830 and Psilorhynchus balitora (Hamilton, 1822) collected from Ranganadi river in Lakhimpur district of Assam, India for which no LWRs and LLRs are available. While sampling monthly between April 2012 and July 2016, a total of 987 specimens were collected (B. brucei = 427, and P. balitora = 560). Cast nets were used (2 ‐ 10 mm mesh sizes; 2–2.5 m length). The values of the parameter slope (b) in the LWR were determined as 3.194 (male = 3.047 and female = 3.224) for B. brucei and 3.490 (male = 3.480 and female = 3.502) for P. balitora. Present investigation reports new maximum total length for both the fishes.     

Length–weight relationships of three small indigenous fish species from the Lower Brahmaputra,India

Length–weight relationships (LWRs) for three small indigenous fish species from the lower Brahmaputra in Assam, India: Glyptothorax telchitta, Nangra assamensis, and Gudusia chapra were studied on a monthly basis from February 2015 to January 2016. Various fishing gear types were employed: cast nets (9′ ½”), gillnets (30 × 0.9 m, 0.5″; 60 × 3 m, 1.5″) and mosquito nets (20 × 6 m, 0.04″). No previous reference is available on LWR data for two of these species.     

Length–weight relationships of three endangered tidal pool fish species on Jeju Island,Korea

The length–weight relationships (LWRs) of three endangered tidal pool fishes, Spratelloides gracilis (Temminck & Schlegel, 1846), Atherion elymus Jordan & Starks, 1901, and Enneapterygius etheostomus (Jordan & Snyder, 1902), from Jeju Island, Korea, were analysed. A total of 280 specimens were sampled using hand nets (mesh size 1 mm) or by dredge (mesh size 5 mm) from July 2015 to July 2016. This study provides the first LWRs for two species, a new LWR for one species, and a new maximum length data for two species.     

Length-weight relationship of fish species from Central Amazon floodplain

Length-weight relationship (LWR) for 39 freshwater fish species captured in the Catalão Lake, a floodplain area at the confluence of the Amazonas and Negro rivers is presented. LWRs were calculated based on fish sampled over 18 years (1999–2017) using a set of ten gill nets with different mesh sizes, monthly immersed in water for 24-hr with 6-hr interval catches. Measurements were done for standard length (SL – 0.1 cm precision) and total weight (TW – 0.01 g precision). The LWRs were calculated by the linear regression of natural log-transformed SL and TW data: TW = a × SL^b. All statistical analyses were performed with R software. From all species considered, 32 are new LWR records for the international literature as well as for the Amazonian ichythyofauna; additional records expand the known size range for seven species.     

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 relationships of three freshwater cyprinid fish species from Chalakudy River,South Western Ghats,India

This paper provides length‐weight relationships (LWRs) for three freshwater cyprinid fish species: Barbodes carnaticus (Jerdon, 1849), Hypselobarbus kolus (Sykes, 1839) and Tor khudree (Sykes, 1839) from the Chalakduy River in South Western Ghats of India. Fish samples were collected on a monthly basis between April 2011 to March 2012 using gill nets of different mesh sizes (3.5–10 cm). LWRs for these three species had not been previously reported in FishBase.     

Length‐weight relationship and relative condition factor of five indigenous fish species from Torsa River,West Bengal,India

Length‐weight relationships (LWRs) for five indigenous fish species under five genera and two families, namely Cyprinion semiplotum (McClelland, 1839), Barilius barna (Hamilton, 1822), Barilius barila (Hamilton, 1822), Gagata sexualis Tilak, 1970 and Pseudolaguvia shawi (Hora, 1921) were studied from Torsa River in West Bengal, India. Sampling was done at quarterly intervals from November, 2015 to December, 2016 and a total of 701 fish specimens were collected using cast nets (mesh size of 15–20 mm), gill nets (mesh size 20–35 mm) and bamboo traps. In the present study, b value ranges from 2.686 to 3.268. LWRs for these fish species (except P. shawi) have not been reported in FishBase. A new maximum length has been recorded for P. Shawi and G. sexualis. The relative condition factor (Kn) values was found to range from 1.004 to 1.028.     

Length‐weight relationships for three species of common scorpaenoids from Singapore

This study provides length‐weight relationships (LWR) for three common marine species collected from Singapore, a small tropical island country in southeast Asia, where monthly collections using seine netting and fish trapping were performed at six sites from January to December 2010. The LWRs of these three species were BW = 0.0348 SL^3.002 (n = 305, r² = .9747) for Paracentropogon longispinis, BW = 0.0315 SL^3.039 (n = 104, r  = .9798) for Trachicephalus uranoscopus and BW = 0.0651 SL^3.021 (n = 70, r² = .9601) for Synanceja horrida respectively.