Gymnocypris chui Tchang,Yueh & Hwang, 1964 and Gymnocypris scleracanthus Tsao,Wu, Chen & Zhu, 1992 from Lake Langcuo,Qinghai‐Tibet Plateau

This study presents length‐weight relationships (LWRs) for two sympatric species of the subfamily Schizothoracinae (Cyprinidae), Gymnocypris chui and G. scleracanthus, captured in Lake Langcuo in Tibet, China. A total of 193 specimens were collected in June and July of 2014 and 2015 using gill nets of different mesh sizes (mesh size: 2 × 2 cm, 3 × 3 cm). Specimens included 76 G. chui and 117 G. scleracanthus. The values of parameter b in the LWRs equations were estimated as 2.875 for G. chui, and 2.773 for G. scleracanthus, respectively. These are the first LWRs records for the two sympatric species.     

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 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 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 relationships of 11 fish species from the Min River Estuary and its adjacent waters,Fujian Province,China

Length-weight relationships (LWRs) were estimated for 11 fish species from the Min River Estuary and its adjacent waters, Fujian Province, China. All samples were collected using gillnets (mesh size 45 mm) and bottom trawls (mesh sizes 45 mm at the main webbing and 25 mm at the cod end) seasonally in 2017 and 2018. The parameters for the LWRs were estimated, along with the basic Statistical analyses for total length and weight ranges as well as the 95% confidence intervals for the intercept (a) and the slope (b) of the regression lines. Further, the coefficient of correlation indicated that the LWRs were highly significant (all r² > .95, p < .001). This study provides the new maximum total lengths (TL_max) for Coilia grayii (33.0 cm), Johnius taiwanensis (20.9 cm), Johnius trewavasae (22.0 cm) and Cynoglossus sibogae (22.0 cm).     

Length–weight relationships of four small indigenous fish species from an inland artisanal fishery,Bangladesh

This study reports the length–weight relationships (LWRs) of four small indigenous species, Trichogaster lalius (Hamilton, 1822), Nandus meni (Hossain & Sarker, 2013), Lepidocephalichthys annandalei (Chaudhuri, 1912) and Botia dario (Hamilton, 1822) collected between July 2015 and August 2016 from fishermen's catches landed in an inland fish landing center, northeastern Bangladesh. In the study, a new maximum total length (TL) is given for L. annandalei and LWRs of three species T. lalius, N. meni and L. annandalei for the first time in FishBase. Estimated LWRs were W = .014 TL^3.17, (r² = .982) for T. lalius, W = .006 TL^3.38, (r² = .961) for N. meni, W = .004 TL^3.27, (r² = .965) for L. annandalei and W = .020 TL^2.87, (r² = .978) for B. dario.     

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 for five fish species from the middle reaches of the Yangtze River,China

Length–weight relationships (LWRs) for five fish species which were captured by trap‐nets and gillnets (major mesh size: 1–10 cm) from the middle Yangtze River, China (29°47′ – 29°26′N; 112°51′ – 113°08′E) were determined in September 2017. These were Acheilognathus hypselonotus (Bleeker, 1871), Culter oxycephaloides Kreyenberg & Pappenheim, 1908, Distoechodon tumirostris Peters, 1881, Sarcocheilichthys nigripinnis (Günther, 1873) and Micropercops swinhonis (Günther, 1873). The LWRs were estimated using the logarithmic form of the formula W  =  a  ×  L^b. The b value ranged from 2.879 for A. hypselonotus to 3.285 for M. swinhonis. LWRs for four fish species and new maximum lengths for three species are presented to FishBase for the first time.     

Length–weight and length–length relationships of three fish species from the Heihe River,northwest China

Length‐weight (LWRs) and length–length (LLRs) relationships are reported for three fish species belonging to two families and two genera from the Heihe River, northwest China. Fish samples were collected using trap nets (mesh size 1 cm) in May and December of 2016, and April and October 2017. Standard length (SL) and total length (TL) for each individual were measured to the nearest 0.1 cm by digital slide caliper and each body weight (BW) was measured to an accuracy of 0.1 g using digital balance. The b‐values for LWRs varied from 2.580 to 3.164 (r² > .956). The results further indicated that the LLRs were highly correlated (r² > .991; p < .01). This study presents the first references on LWRs for Gymnocypris chilianensis and Triplophysa hsutschouensis, and LLRs for G. chilianensis, Triplophysa leptosoma and T. hsutschouensis. This biometric data and their relationships are relevant to the management and conservation of local fishes and fisheries.     

Length-weight relationships of 6 fish species caught in a Mediterranean lake (Trichonis-NW Greece)

In the present study the length–weight relationships (LWRs) of 6 fish species which are endemic to Western Greece, caught in the natural Lake Trichonis by experimental gillnets and electrofishing were estimated. Benthic (mesh size 5–55 mm; height 1.5 m; length 30 m) and pelagic (mesh size 6.25–55 mm; height 6 m; length 27.5 m) Nordic type multimesh gillnets were used seasonally, between February 2019 and November 2019, at different depth zones (0-57m). Electrofishing (80 Hz) conducted in the littoral zone of the lake during four samplings (2018, 2019). All the estimated LWRs were highly significant (p < .05) with high correlation coefficient (r² ≥ 0.962). The estimated b values ranged from 3.058 to 3.344. For five of the studied species (Trichonis spined loach (Cobitis trichonica Stephanidis 1974), Trichonis blenny (Salaria economidisi Kottelat 2004), Trichonis rudd (Scardinius acarnanicus Economidis 1991), Acheloos roach (Leucos panosi (Bogutskaya & Iliadou 2006)) , Hellenic minnowroach (Tropidophoxinellus hellenicus (Stephanidis 1971)) new maximum total body lengths (TL) were recorded, while for two species (T. hellenicus and L. panosi) LWRs are presented for the first time.     

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 relationship of Rastrelliger brachysoma (Bleeker, 1851) and Rastrelliger faughni Matsui, 1967 from the Andaman Islands,India

This study reports the length–weight relationships (LWRs) of Rastrelliger brachysoma (Bleeker, 1851) and Rastrelliger faughni Matsui, 1967 from Andaman Islands, India. Sample sizes for the two fish species were 78 for R. brachysoma and 57 for R. faughni. Fish collected monthly from Junglighat fish landing center. Fish were captured by commercial ring seine units (mesh size ranging from 2 to 4 cm) between February 2016 and March 2017. LWRs were established as TW = 0.0042TL^3.332 (r² = .989) for R. brachysoma and TW = 0.0096TL^3.022 (r² = .980) for R. faughni.     

Length–weight relationships of three catfish species from a tributary of the Dhaleshwari River,Bangladesh

The present ichthyological report describes the length‐weight relationships (LWRs) of three catfish species (Eutropiichthys murius, Nangra nangra and Gagata viridescens) belonging to two families from the Kaliganga River, a tributary of the Dhaleshwari River, Bangladesh. The analyses included 306 specimens collected monthly from fishermen's catches during October 2015 to April 2016. Ranges of regression parameters a and b of the three species were within 0.0058–0.0099 and 2.900–3.142, respectively with highly correlated coefficients of determination (r² > .995; p < .001). The LWRs for all three species presented herein for the first time with a new maximum length record for N. nangra.     

Length–weight and length–length relationships of five fish species from the Dadu River and its tributaries,southwest China

Length‐weight (LWRs) and length–length (LLRs) relationships are reported for five fish species belonging to two families and five genera from the Dadu River and its tributaries, southwest China. In total, 605 specimens were collected by electrofishing and gillnets (mesh size ranging from 1.5 to 3.5 cm) in May and October 2013, May and October 2014, May and November 2015, and April and October 2016. The b‐values for LWRs varied from 2.571 to 2.952 (r² > .915). The results further indicated that the LLRs were highly correlated (r² > .978; p < .01). The two LWRs, five LLRs, and two maximum lengths are presented to FishBase for the first time. This biometric data and their relationships are relevant to the management and conservation of local fishes and fisheries.     

New maximum size records and length–weight relationships for two species,Corica soborna (Hamilton, 1822) and Mystus bleekeri (Day, 1877), from the Ganges River (NW Bangladesh)

This study records new maximum lengths and provides length–weight relationships (LWRs) for two small indigenous fishes, Corica soborna (Hamilton, 1822) and Mystus bleekeri (Day, 1877), from the Ganges River in northwestern Bangladesh. Fishes were sampled sporadically using gill nets and cast nets from August 2015 to July 2016. New maximum recorded lengths weere 5.3 cm total length (TL) for C. soborna and 17.7 cm TL for M. bleekeri. The LWRs were highly significant (p < .001) with r² values >.958. These findings will play a significant role in the fisheries resource management.     

Length–weight relationships for eight fish species from the Pearl River Delta,China

Length–weight relationships (LWRs) were estimated for eight native fish species collected in the lower reaches of the Pearl River, Guangdong Province, South China. Fish were sampled in March and September 2014 and January 2015, using gillnets with various mesh sizes (5–8 cm) and trawl nets with a 3 cm mesh size. A total of 568 specimens of the eight species were analyzed. The r² values for these species ranged from 0.951 to 0.991. The b values ranged from 3.00 for Takifugu ocellatus and Moolgarda cunnesius, to 3.57 for Clupanodon thrissa. New maximum total lengths are recorded for Takifugu ocellatus (17.6 cm) and Liza carinata (24.4 cm). For five species (Clupanodon thrissa, Megalobrama terminalis, Collichthys lucidus, Coilia grayii, Takifugu ocellatus), the LWRs are presented to fishbase for the first time.     

Length-weight and length-length relationships of three fish species from the lower Yalong River,China

Length-weight relationships (LWRs) and length-length relationships (LLRs) were evaluated for three endemic fish species sampled from the lower Yalong River and its biggest tributary (the Anning River), in China. Specimens were captured using set gillnet (mesh size 4 cm) and backpack electro-fishing (power output 400 W, depth fished 1 m, area covered 3 m²) from June to July 2018. LWRs and LLRs are presented for the following species (Sinogastromyzon sichangensis, Micropercops swinhonis and Percocypris pingi).     

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 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 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.