Length‐weight relationships of 10 coastal fish species from the Visakhapatnam coast,India

We analysed the length‐weight relations (LWRs) of 10 fish species inhabiting different habitats from Visakhapatnam, Coast of India. Samples were obtained between August 2013 and December 2016 from commercial trawlers at the local fish landing centre (16.98°N–20.20°N, Long.82.19°–86.53°E). Fishes were captured between 100 and 300 m depth with demersal trawl net (head rope length: 46 m and cod end mesh size: 40 mm with a 38 m high speed. Total length (TL; nearest to 0.1 cm) and body weights (nearest to 0.1 g) were taken from each individual. This study provides new maximum length data for two species (Archamia bleekeri (Günther, 1859) and Ostorhinchus fleurieu (Lacepède, 1802), and LWR estimates for rare deep reef associated fishes are provided for the first time. All LWRs were significant with r² values ranging from .908 for Sargocentron praslin (Lacepède, 1802) to .981 for Parapercis pulchella (Temminck & Schlegel, 1843) and “b” values ranged from 2.5216 for Parapercis pulchella (Temminck & Schlegel, 1843) to 3.4746 for Ostorhinchus fleurieu Lacepède, 1802.     

“Length weight relationship of four non commercial fish species from the Southwest coast of India”

Length weight relationships (LWRs) were estimated for four species of low value fishes that belongs to four families from the southwest coast of India. The specimens of, Callionymus margaretae, Dactyloptena peterseni, Rogadius serratus and Minous inermis were collected for a period of 1 year from the fishing trawlers of Cochin Fisheries Harbour (Lat. 09° 56′ 327″ N, Long. 76° 15′ 764″ E). The estimated allometric coefficient b values ranged from 2.5020 (Rogadius serratus) to 3.2438 (Dactyloptena peterseni) and r² values ranged from 0.9492 (Rogadius serratus) to 0.9869 (Dactyloptena peterseni). All the LWRs were highly significant, with p < .001.This study provides the first estimate of LWRs for these low value by catch fish species.     

Length–weight relationships of nine freshwater fish species from the Liujiang River,Guangxi, China

Studied were the length–weight relationships (LWRs) of 599 fish specimens covering four families, nine genera and nine species (Sinibrama macrops, Acrossocheilus parallens, Microphysogobio fukiensis, Squalidus wolterstorffi, Pseudohemiculter dispar, Tachysurus fulvidraco, Hemibagrus macropterus, Pseudobagrus crassilabris and Siniperca kneri) collected in the Liujiang River, a tributary of the Pearl River, in March 2014, September 2014 and March 2015. The b value varied between 2.385 (P. crassilabris) and 3.178 (P. dispar), with the mean b = 2.85 at P < 0.001 for all nine species.     

Length-weight relationships of six tropical estuarine fish species from Pulicat lagoon,India

Length–weight relationships (LWRs) of six finfish species under two families of the order Perciformes collected from Pulicat lagoon (India) are presented in this study. The fish specimens were collected weekly from the catches of shore seine net (with a mesh size of 50mm at the main webbing and 10 mm at the cod end) operated in the lagoon at an average depth of 2.5 m by the local fishermen during the period from July 2018 to April 2019. This study reports the LWRs for five gobiid and one siganid fish species which have no earlier reports on LWRs. The calculated ‘b’ value ranged from 3.538 (Favonigobius reichei) to 2.677 (Oxyurichthys microlepis) and ‘a’ value varied from 0.0041 (Favonigobius reichei) to 0.0199 (Acentrogobius cyanomos). This study also reports the new maximum total length (TL_max) for the gobiid fish species Oxyurichthys microlepis.     

Length–weight relationships of three fish species from the upper reaches of the Beijiang River,Shaoguan, China

Fish assemblages were randomly collected in March 2015 from the upper reaches of the Beijiang River, Shaoguan, China. Fish were sampled on 10 occasions using gill nets (mesh size: 3 cm) and the length–weight relationships (LWRs; W = a × L^b) of three native species recorded: Xenocypris davidi, Xenocypris macrolepis and Culter recurviceps. The exponent b varied from 2.803 to 3.096 and r² values ranged 0.985–0.992. This is the first report on the LWRs of fish from this area, with valuable results for the research, management and conservation of fishery resources in the upper reaches of the Beijiang River.     

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 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 14 Indian freshwater fish species from the Betwa (Yamuna River tributary) and Gomti (Ganga River tributary) rivers

The length‐weight relationships (LWRs) were studied of 588 fish covering eight families, 13 genera and 14 species (Notopterus notopterus, Gudusia chapra, Labeo calbasu, Puntius sarana, Cirrhinus mrigala, Ompok bimaculatus, Mystus tengara, Mystus cavasius, Sperata aor, Sperata seenghala, Eutropiichthys vacha, Wallago attu, Rhinomugil corsula, and Mastacembelus armatus) captured in the Betwa River (tributary of the Yamuna River) and Gomti River (tributary of the Ganga River) from December 2007 to January 2009. The b values varied between 2.4 (M. armatus) and 3.52 (P. sarana), with the mean b = 2.96 at P < 0.001 for all species. The observations are significant for conservation and management because the Betwa River has been approved under India’s first interlinking plan with the Ken River, and no length‐weight data had thus far been reported for the Gomti River. The objective was to evaluate the LWRs of these two unstudied rivers for fisheries management.     

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 of three Clupeiformes species from the Southeast coast of India,Bay of Bengal,Eastern Indian Ocean

This study deals with the length-weight relationships (LWRs) of three commercially important marine fishes belonging to the family Clupeidae from the major landing centers in Tuticorin, Mandapam, Thondi, Nagapattinam and Chennai in southeast coast of India. Monthly sampling were done at the respected landing centers from June, 2018 to April, 2019 from the commercial trawlers (with cod-end mesh size of 25–35 mm) and gill netters (with different mesh size vary from 20 to 170 mm). The estimated ‘b’ values ranged from 3.1215 (Sardinella albella) to 3.1819 (Amblygaster clupeoides) and ‘a’ values varied from 0.0059 (A. clupeoides) to 0.0074 (S. albella). The study also provides a new maximum total length (TL_max) for two species A. clupeoides and Sardinella fimbriata.     

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 and length–length relationships of 26 fish species from the Yiluo River,a tributary of the Yellow River,China

From February to October 2016, a total of 9,754 fish specimens were collected from the Yiluo River, a tributary of the Yellow River, China's second longest river. Based on these samples, length–weight relationships (LWRs) and length–length relationships (LLRs) were estimated for 26 species. Among these data, LWRs for 1 species, LLRs for 11 species, and maximum total lengths for six species were not previously recorded in FishBase. The a values of the LWRs varied between 0.0019 and 0.0116, and b values from 2.805 to 3.883. All regressions for LWRs and LLRs were highly significant (p < .001). These results will be useful for sustainable management and conservation of the fish resources in the Yiluo River and the Yellow River ecosystem.     

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 relationship of seven fish species from the temporary habitat,Pantanal wetland,Brazil

The length–weight relationships (LWRs) were estimated of seven fish species from 22 localities in the Pantanal wetland between Mach 2006 and April 2011. Fish were sampled using seven gill nets (20 × 1.5 m; mesh size: 12, 15, 18, 20, 25, 30 and 50 mm between opposing knots) and throw traps (made of 1 m³ metal cubes, covered by a 1.5 mm nylon mesh). Standard length and weight were measured and used to calculate the LWR parameters. Values for parameter b varied from 2.87 (Apistogramma borellii) to 3.29 (Hoplerythrinus unitaeniatus) and, such values are within the expected range.     

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 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 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 relationships for seven fish species from the Nandujiang River in Hainan Island,China

Length–weight relationships (LWRs) were determined for seven fish species collected during 2014 and 2015 between January and July each year from Nandujiang River. The study used drift gillnet with 4 cm mesh (100 m long × 1.2 m high) as well as electrofishing. The parameter “b” of the LWR equations varied between 2.963 to 3.171 for the species studied.     

Length–weight relationships for six fish species in Iskenderun Bay (Eastern Mediterranean Sea coast of Turkey)

The length–weight relationships (LWRs) were estimated for six non‐indigenous fish species, namely, Apogon smithi (Kotthaus, 1970); Ostorhinchus fasciatus (White, 1790); Pomadasys stridens (Forsskål, 1775); Champsodon capensis Regan, 1908; Torquigener flavimaculosus Hardy & Randall, 1983; and Tylerius spinosissimus (Regan, 1908) from Iskenderun Bay, eastern Mediterranean Sea. Their length–weight relationship b values ranged from 2.902 to 3.501, and all regressions were found to be significant for all six species (P < 0.001). This study is the first reference on length–weight relationships for these six non‐indigenous fish species from the Eastern Mediterranean Sea coast of Turkey.     

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.