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 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 nine freshwater fishes from six rivers of the Western Ghats of India

Length–weight relationships (LWRs) were estimated for nine freshwater fish species collected three times using a scoop net (mesh size 0.3–0.5 cm), cast net (mesh size 1–1.5 cm) and gillnet (mesh size 2.5–4.5 cm) from six rivers of the Western Ghats of India during August 2017–October 2018. The b values for LWRs varied from 2.862 to 3.656 (R² > 0.916 and p < 0.0001 for all species).     

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 of insular cichlids from Patos Lagoon estuary,subtropical Brazil

The present study reports the length‐weight relationships (LWRs) of three cichlids (Crenicichla lepidota, Cichlasoma portalegrense and Geophagus brasiliensis) collected in a system of pools of the largest estuarine island of Patos lagoon, southern Brazil. Fishes were sampled during random field trips performed from April 2015 to April 2016, using a beach seine (net 5 × 2 m; mesh size 5 mm) and a hand net (diameter 45 cm, mesh size 2 mm). The LWRs for C. portalegrense are presented herein for the first time.     

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 relationships of six fish species from mangroves of Qinzhou Harbor,Southern China

The length–weight relationships (LWRs) for six species were estimated. Fish were captured in the mangroves of Qinzhou Harbour, China, but also some specimens were purchased from fishermen. The sampling was undertaken monthly between May 2011 and April 2012 using seines (mesh size 5–10 mm; height 4 m; length 400 m) and traps (mesh size 8.5 mm; 35 cm² × 10 m for one unit) at seven sampling sites. Standard length was measured (precision 0.1 cm) and weight determined (precision 0.01 g) after preservation in formaldehyde (10%). Besides the equation parameters a (intercept) and b (slope) we determined also the 95% confidence limits for both parameters as well as the coefficient of correlation.     

Length-weight relationships of fish species from the Stung Russei Chrum River basin,Kingdom of Cambodia

This study evaluated the length-weight relationships (LWRs) for three teleost fish species sampled from the Stung Russei Chrum River basin, Kingdom of Cambodia. The fish were collected during two dry seasons (April 2019 and November 2019) and one rainy season (October 2018) using monofilament trammel nets (2–12 cm mesh size), cast net (mesh size 2 cm) and scoop-nets (mesh size with 0.3 cm). Results showed that all fitted regressions were highly significant and the coefficients of determination (r²) were high. This study expanded the value of maximum total length for Cyclocheilichthys apogon and Poropuntius laoensis while reported the wider ranges of total mass for Poropuntius laoensis. Moreover, our present study also provided the novel LWRs records for Hemibagrus filamemtus.     

Length-weight relationship of fish species captured around an artificial offshore reef (northern Rio de Janeiro,Brazil)

The present work provides length-weight relationships (LWRs) for fish species captured around artificial offshore reef deployed 5 km from Guaxindiba Port, northern Rio de Janeiro, Brazil. The fish were captured during two sampling periods each year between 1996 and 2017 using bottom gill nets (25 m_length × 3 m_depth; 30 mm mesh). The fish were kept on ice and the biometric data, including total length (cm) and total wet weight (g) were determined in the laboratory. A total of 16 species belonging to 10 families were analyzed with Sciaenidae being the species richest family (5 spp) in the samples. The new value of LWRs for Sphyraena guachancho and new maximum sizes recorded for seven species highlight the scarcity of information on biological aspects of South America coastal fishes. These LWRs should assist fisheries scientist and managers to complement their further studies of population parameters to improve management decisions.     

Length–weight relationships of six marine fish species from the coast of Ghana

This study estimated the LWRs of six fishes from the coastal waters of Greater Accra, Ghana. Data was obtained monthly from June 2018 to July 2019 and analyzed for total length and weight measurement to the nearest 0.1 cm and 0.01 g respectively. The sampling was done using hooks and line as well as monofilament and multifilament gear types. The mesh sizes for both monofilament and multifilament gear types ranged from 0.5 to 2 inches whereas the hooks types ranged from 6 to 12. The b values for the assessed species were within the range 2.8–3.2. There was strong correlation between the length and weight of all the species (R² > .95). This study provides LWRs for Cynoglossus senegalensis, Scorpaena histrio and Pseudotolithus senegalensis and larger maximum total length (TLmax) for Syacium micrurum, Eucinostomus melanopterus and Brachydeuterus auritus.     

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 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 Acanthopagrus longispinnis (Valenciennes, 1830), Raconda russeliana (Gray, 1831) and Coilia neglecta (Whitehead, 1967) from the Bay of Bengal coast,Bangladesh

Current study reports the length‐weight relationships (LWRs) of three marine fish species collected from the fishermen catches covering three seasons i.e., rainy, autumn and winter between June, 2016 and February, 2017. Fishermen caught the species using beach seine net (3.5 cm mesh size) and set bag net (0.5 cm mesh size) up to 200 m far away from the shoreline. The LWRs for fish species were W = 0.0180TL^3.192 for A. longispinnis, W = 0.0109TL^2.971 for R. russeliana and W = 0.0098TL^2.942 for C. neglecta with their r² values of 0.971, 0.962 and 0.997, respectively.     

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 relationships of seven cyprinid fish species from the Kaptai Lake,Bangladesh

Length-weight relationships (LWRs) were estimated for seven small indigenous cyprinid fish species including Securicula gora, Osteobrama cotio, Esomus lineatus, Pethia gelius, Megarasbora elonga, Gonialosa manmina and Glossogobius aureus occurring in the Kaptai Lake, Bangladesh. Fish were collected monthly basis between March and October, 2018 from fishermen catches landed in the fish landing center, Rangamati. Fishermen operated lift net (mesh size < 0.5 cm), punti net (mesh size < 0.5 cm) and cast net (mesh size < 0.5 cm) for capturing these species. The value of exponent b ranged between 2.769 and 3.212 and regression parameter r² was between 0.926 and 0.992. New maximum total lengths were recorded for E. lineatus and G. manmina in this study.     

Length–weight relationships of three fish species from Kerala waters,south‐west coast of India

Length–weight relationships (LWRs) of three fish species: Scomberomorus commerson, Alepes vari, and A. kleinii were estimated from Kerala waters, south‐west coast of India. Fish were captured between June 2016 and June 2017 by various gears such as ring seine (8–26 mm mesh size), trawl (30–40 mm cod end mesh size), hook and line (hook number VI–XII), smaller mesh sized drift gill net (26–90 mm) and larger one (120–170 mm) for bigger size fishes. Fish were collected on weekly basis from Cochin Fisheries Harbour (Lat. 09°56′327″N, Long. 76°15′764″E), Munambam Fisheries Harbour (Lat. 10°10′965″N, Long. 76°10′258″E), Kalamukku (Lat. 09°59′924″N, Long. 76°14′564″E) and Chellanam (Lat. 09°47′950″N, Long. 76°16′551″E). All LWRs were significant with r² values ranged from 0.944 to 0.996 and b values ranged from 2.722 to 3.021 (p < .001). In addition, this study provides the information on LWRs and new maximum size for Alepes vari and A. kleinii.     

Length‐weight relationship of Thryssa malabarica (Bloch, 1795) and Thryssa dayi Wongratana, 1983 from Kerala,southwest coast of India

The present study reports the length‐weight relationships (LWRs) of two clupeoid fish species, Thryssa malabarica (Bloch, 1795) and Thryssa dayi Wongratana, 1983 from Kerala waters, southwest coast of India during the period October 2015 to September 2016. Altogether 88 specimens of T. malabarica and 97 T. dayi were collected on weekly basis from gill nets (mesh size, 2.6–5.0 cm) and ring seines (mesh size, 0.8–2.6 cm) during the period. The value of parameter b in the equation of LWRs was estimated as 3.237 and 3.248 for T. malabarica and T. dayi respectively.     

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.     

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 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.