Length‐weight relationships of three fish species from Beibu Gulf in China

The length–weight relationships (LWRs) were analyzed for three fish species collected from Beibu Gulf between October 2012 and March 2013. The study used bottom trawl with 40 mm mesh size. The values of parameter b varied from 2.8495 to 3.0277.     

Length–weight relationships of 23 fish species from Southeastern Brazil

Length–weight relationships of 23 fish species from the Guaratiba mangrove area in southeastern Brazil were estimated. The value of the parameter b ranged from 2.63 to 3.39 (median = 2.97). This study presents the first estimation of LWR for two species (Ctenogobius stomatus and Ctenogobius boleosoma). New maximum length records were obtained for two species (Poecilla vivipara and Ctenogobius stomatus).     

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 of three cyprinid fishes from Sirwan River,Kurdistan and Kermanshah provinces in western Iran

The length–weight relationships (LWR) for three fish species collected in Sirwan River, located in Kurdistan and Kermanshah provinces, western Iran, were estimated. The values of the slope parameter (b) in the length–weight relationship equations were determined as 3.086 for Alburnus mossulensis, 3.382 for Alburnus filippii and 3.425 for Capoeta damascina, all significantly different from the expected b = 3 value, indicating a positive allometric growth pattern for all the three species.     

Length‐weight relationships of three indigenous fish species from National Nature Reserve for Rare and Endemic Fishes of the upper Yangtze River,China

Length‐weight relationships (LWRs) were estimated for three small indigenous fish species, (Sinogastromyzon szechuanensis, Sinogastromyzon sichangensis and Sinocrossocheilus labiatus) in the upper Yangtze River, China. Samples were collected using three types of local traditional fishing gears, including gill nets (mesh size: 1 cm), fish cages (mesh size: 0.5 cm), and electrofishing techniques (CWB‐2000 P, 12V, 250 Hz), in April, July and October 2013 and 2014, and April and October 2016. The sample size for each species were gathered separately, with 100 for S. szechuanensis, 381 for S. sichangensis and 49 for S. labiatus from National Nature Reserve for rare and endemic fishes of the upper Yangtze River, China. The length‐weight relationship parameter values of b were calculated as 2.986 for S. szechuanensis (b: 2.854–3.118), and 3.284 for S. sichangensis (b: 3.209–3.359) and 3.119 for S. labiatus (b: 2.911–3.326). The primary data will be meaningful for further research about sustainable development and scientific management of fishery resources of the upper Yangtze River.     

Length‐weight relationships of three fishes from the Nujiang River,China

The length‐weight relationships (LWR) for three fish species collected from the Nujiang River, China, were determined. Fishes were caught quarterly by drift gill net (stretched mesh size: 4 cm, depth: 2–4 m) and cast net (mesh size 1 cm; depth: 1–2 m) from May 2016 to July 2017. The values of parameter b in the LWR equations were estimated as 2.69 for Balitora nujiangensis Zhang & Zheng, 1983, 2.80 for Glyptothorax deqinensis Mo & Chu, 1986 and 2.94 for Pseudexostoma brachysoma Chu, 1979, respectively.     

Length–weight relationships and length at first maturity for fish species in the upper Miranda River,southern Pantanal wetland,Brazil

Length–weight relationships (LWR) were estimated for 17 species and total length at first maturity (L50) for three species of freshwater fishes from the Miranda River, southern Pantanal, Brazil. The b values were compared for some species in the Paraguay River basin with the northern (Cuiabá River) part of the basin; differences in length–weight relationships were significantly different for Pseudoplatystoma corruscans, P. reticulatum (syn. P. fasciatum). First references on L50 and LWR are presented for two and eight fish species, respectively, as well as the new maximum total length for two species.     

Length–weight relationships of four fish species from Vembanad-Kole Wetland (Kerala,India)

The length–weight relationships (LWRs) of four fish species were determined from Vembanad-Kole Wetland, Kerala, India between June 2015 and May 2016. Fish samples were collected monthly from various fishing gears such as gill nets (50 m long and 1.5 m height, mesh sizes 30–100 mm, soaking time 8 hr) and seine nets (mesh sizes 8–16 mm). Values of the parameter b ranged from 2.896 to 3.165 and such values are within the expected range. This study reports the new maximum total length for Channa pseudomarulius and Hyporhamphus xanthopterus.     

Length–weight and length–length relationships for seven fish species from the Zohreh River,Iran

Length–weight and length–length parameters were calculated for seven fish species belonging to five families in the Zohreh River, Iran. The weight–length relationships were estimated using the equation W = aL^b. The b values varied between 2.72 and 3.33, with a mean ± SD of 2.88 ± 0.28. The b values parameter in the length–weight relationship equations were calculated as 3.15 for Alburnus mossulensis Heckel, 1843; 3.78 for Barilius mesopotamicus Berg, 1932; 2.86 for Cyprinion macrostomum Heckel, 1843; 2.89 for Nuchequula gerreoides (Bleeker, 1851); 2.80 for Mastacembelus mastacembelus (Banks & Solander, 1794); 2.72 for Liza abu (Heckel, 1843); and 3.19 for Paraschistura nielseni (Nalbant and Bianco, 1998). This study presents the first LWR and LLR references for these species in the Zohreh River.     

Length–weight relationships of nine fish species from the Tongjiang section of the Songhua River,China

Length–weight relationships were evaluated for nine fish species from the Tongjiang section of the Songhua River in China. A total of 675 fish specimens were collected from 4 May to 29 October 2014. Length–weight relationships for six fish species (Romanogobio tenuicorpus, Leuciscus waleckii, Opsariichthys bidens, Microphysogobio amurensis, Pelteobagrus ussuriensis and Misgurnus mohoity) were new to FishBase in 2015, but the length–weight relationships of P. ussuriensis was studied by Ma in 2015. New data on M. mohoity is offered, and this study also shows new maximum total lengths for three fish species. The r² values ranged from .95 to .99. Values of b varied from 2.504 to 3.471.     

Length–weight relationships for six fish species from the middle of the Yalu Tsangpo River,China

This paper reports the length–weight relationships for six fish species belonging to the Cyprinidae from the middle of the Yalu Tsangpo River in China. Samples were obtained by electroshock and drift net fishing techniques (mesh size 2 cm × 3 cm; 200 m net length) in April and September to October 2014. Length–weight relationships estimates for these species were not available in FishBase. A total of 737 specimens were used to estimate the a and b parameters. New maximum total lengths are also reported for six species. The r² values range from 0.98 to 0.99. Values of b vary from 2.88 to 3.19.     

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–length and length–weight relationships of oilfish (Ruvettus pretiosus), escolar (Lepidocybium flavobrunneum), snake mackerel (Gempylus serpens), and longnose lancetfish (Alepisaurus ferox) from the Gulf of Mexico and the western North Atlantic Ocean

Oilfish, escolar, snake mackerel (order Aulopiformes, family Gempylidae), and longnose lancetfish (order Perciformes, family Alepisauridae) sampled from the western North Atlantic and the Gulf of Mexico were analyzed for length–weight and length–length relationships. These species are encountered as occasional bycatch of pelagic longline fisheries. The fish (161 specimens, 19.0–149.1 cm TL) were collected over a 3‐year period (January 2007–January 2010) from pelagic longline gear targeting swordfish and tuna. For each species, 95% confidence limits (CI) of parameters b and log a and regression coefficients (r²) were calculated for log‐transformed length–weight relationships. The length–weight parameter b for all species ranged from 2.881 to 3.358, with regression coefficients (r²) ranging from 0.75 to 0.98. Linear relationships between fork lengths, standard lengths, and total lengths were also calculated.     

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).     

Length–weight relationships of 33 fish species from New Zealand

Length–weight relationships are presented for 33 fish species from New Zealand. The parameters a and b of the equation W = aL^b were estimated. Parameter b ranged from 2.51 (Pseudocaranx dentex) to 3.51 (Alepocephalus antipodianus) with a mean of 3.12 ± 0.24. Most of these estimates (90.9%) were between 2.8 and 3.4. Maximum lengths and depths of catch are updated for nine species.     

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 relationships of four fish species from the Beibu Gulf,South China Sea

The length–weight relationships of four fish species: Lophiomus setigerus (Vahl, 1797), Uranoscopus oligolepis Bleeker, 1878, Cynoglossus oligolepis (Bleeker, 1855), and Cynoglossus arel (Bloch & Schneider, 1801) were determined. Specimens were collected from the Beibu Gulf in the South China Sea by using bottom trawl nets (mesh size 4.0 cm, at a towing speed about 3 knots) in the seasonal investigations from August 2010 to May 2011. The values of parameter b of these four species ranged from 2.982–3.489 and remained within the normal range of 2.5–3.5.     

Length–weight and length–length relationship of two endemic snakehead fish species from Brahmaputra river basin,Assam, India

Length–weight relationships (LWRs) and length–length relationships (LLRs) of two endemic Channid fish species, Channa aurantimaculata Musikasinthorn, 2000 and C. stewartii (Playfair, 1867) were studied from Brahmaputra River basin in Assam, India. Sampling was done from May to December, 2017 and a total of 81 fish specimens were collected using bamboo traps. In the LWRs, b value for C. aurantimaculata and C. stewartii were 3.0456 and 2.9172 respectively. Maximum size recorded for C. aurantimaculata in the present study (34.1 cm) was higher than previous record in FishBase (19.1 cm).     

Length–weight relationships of six fish species from Tapajós River,Eastern Amazon,Brazil

The present study reports the length–weight relationships of six fish species from the Tapajós River: Curimata inornata, Geophagus altifrons, G. neambi, Pachyurus junki, Pseudoloricaria laeviuscula and Pristobrycon striolatus. No previous LWR information was available for these species in the FishBase database. Coefficients for the parameter b varied from 2.83 to 3.56.     

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.