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 and Length‐length relations of four fish species from the Chilika Lake,East coast of India

This study reports the length–weight relationship (LWR) and length‐length relationship (LLR) estimated for four fish species inhabiting in Chilika Lake, India. Total 504 specimens were sampled from mono‐filament gill nets (mesh size 12 mm, 22–24 mm, 34–38 mm, 42 mm) during January 2015 to December 2015. The estimated b values from LWR ranged between 2.79 (T. biaculeatus) to 3.29 (C. praeustus). In all species, the relationships between length‐weight and length‐length were highly correlated (p < .05). The study provides first world reports on LWRs and LLRs for all the 4 studied species.     

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 for four mullets from the Chilika lagoon,East coast of India

Current study provides information on Length–weight relationship (LWR) of four fish species of family Mugilidae i.e., Planiliza macrolepis (Smith, 1846), Chelon parsia (Hamilton, 1822), Osteomugil cunnesius (Valenciennes, 1836) and Valamugil speigleri (Bleeker, 1858) from Chilika Lagoon, East coast of India. Samples were collected during monsoon (July 2016), winter (November 2016) and summer (April 2017) seasons from the fisher's boats inside the lagoon while fishing with screen barrier nets (mesh size 18‐38 mm) and gill nets (mesh size 34, 38, 46, 62 and 86 mm). The b values were determined from the data set in LWRs as 2.958 for P. macrolepis, 2.952 for O. cunnesius and 2.919 for C. parsia and 2.883 for V. peigleri. In all species, regression values were statistically significant (p < .05).     

Length–weight relationships of four indigenous fish species from Brahmaputra River,Assam, India

The present study was undertaken with the objective to estimate the length‐weight Relationships (LWRs) for four species collected from the Brahmaputra River, Assam, India. The fish samples were collected quarterly from different sampling sites using gill net (mesh size ranges 1–1.5 cm, locally called Mola lungi jal), cast net (mesh size ranges 1.0–2.0 cm, locally called Kevalijal) and triangular dip nets (mesh size ranges 0.75–1.25 cm locally called khorajal) during the time period between May, 2016 to April, 2018 (2 years). The b value of the LWR ranged from 3.028 (for Parambasis lala) to 3.196 (for Psilorynchus balitora). In this study the relationship between length‐weight were highly correlated (p < 0.05).     

Length–weight and length–length relationships of eight fish species from river Ganga,India

Present study provides length–weight relationships (LWRs) and length–length relationships (LLRs) of eight fish species from river Ganga, India. Specimens were sampled from gill nets (mesh, 22–120 mm), cast nets (mesh, 12–14 mm), and seine nets (mesh, 12 mm) on quarterly basis from September 2016 to September 2017 within the river stretch from 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). The b value ranged from 2.86 (Otolithoides pama) to 3.08 (Polynemus paradiseus), whereas a value ranged from 0.004 (P. paradiseus) to 0.016 (Rita rita). Both relationships (LWRs and LLRs) were found to be highly correlated (p < .001). This study provides first report on LWR for Amblyceps mangois and Osteobrama cotio, whereas new maximum length recorded for Macrognathus pancalus. Furthermore, the estimate of R. rita should be considered as tentative because of the limited size range in the study.     

Length–weight relationships of three fish species from Piediluco Lake,Italy

Length–weight relationships for Leucos aula, Scardinius hesperidicus, and Squalius squalus from the Piediluco Lake were provided. Data were collected by means of electrofishing, gill‐nets (mesh sizes varying from 5 to 55 mm) and fyke‐nets (mesh size 16 mm, total length 8 m, mouth width 1.5 m). The monitoring campaigns were carried out seasonally in the years 2004 and 2011, and in autumn 2012. A total of 5,198 specimens were analyzed. For all the species the value of b ranged between 3.163 for Leucos aula and 3.297 for S. hesperidicus. For L. aula a new maximum total length was also reported.     

Length–weight and length–length relationships of four native fish species of the Qinghai‐Tibet Plateau,China

This study presents the length–weight (LWR) and length–length relationships (LLR) of four fish species (Gymnocypris namensis Wu & Ren, 1982; Herzensteinia microcephalus Herzenstein, 1891; Triplophysa stenura Herzenstein, 1888; and Triplophysa brevicauda Herzenstein, 1888) collected from the Qinghai‐Tibet Plateau, China. A total of 291 specimens was collected using electric fishing (12V), gill nets (mesh size: 2 × 2 cm, 3 × 3 cm) and cast nets (mesh size: 2 × 2 cm), in July 1998 and October 2014.     

Length–weight and length–length relationships of three fish species from the Yarlung Zangbo River in Tibet,China

Length–weight relationships and length–length were evaluated for three fish species (Schizopygopsis younghusbandi Regan, 1905; Ptychobarbus dipogon Regan, 1905 and Oxygymnocypris stewartii Lloyd, 1908) from the Yarlung Zangbo River in Tibet. Specimens were captured monthly using floating gillnets (mesh size 7.5 cm), bottom gillnets (mesh size 6.5 cm), and trap nets (mesh size 1.5 mm) from August 2008 to August 2009, March to August 2012, and March to April 2013. Regression coefficient (b) values of length–weight relationships (LWRs) ranged from 3.045 for P. dipogon to 3.193 for O. stewartii, whereas the a values ranged from 0.0040 to 0.0168 for O. stewartii and P. dipogon, respectively.     

Length–weight relationships of four indigenous freshwater fish species from Khalsi wetland in lower Ganga basin,West Bengal,India

The length‐weight relationships of four indigenous freshwater fishes Parambassis lala (Hamilton, 1822), Trichogaster lalius (Hamilton, 1822), Puntius terio (Hamilton, 1822), and Pethia phutunio (Hamilton, 1822) were determined. Fish samples were collected during December 2013 to May 2015 from Khalsi, a floodplain wetland along the tributary of the River Ganges in West Bengal state, India using different types of gear (castnets, gillnets and drag nets, stretched mesh sizes of 15–20 mm, 20–30 mm and 5–10 mm, respectively). This is the first report on the length–weight relationship parameters of these four species.     

Length–weight relationships for two loach species,Sinibotia superciliaris (Günther, 1892) and Sinibotia reevesae (Chang, 1944) collected from the Tuojiang River,China

Length–weight relationships were determined for two loach species, Sinibotia superciliaris (Günther, 1892) and Sinibotia reevesae (Chang, 1944). Samples were collected with gill nets (30 × 15 m, mesh‐size 1.5 cm) and fish cages (mesh‐size 0.5 cm) as well as by electroshock (CWB‐2000 P, 12 V, 250 HZ) between May 2013 and June 2015 from the Tuojiang River in southwest China. It is believed that the size range covered is close to a commonly known size range of each species. The length–weight relationship values of b were determined as 3.105 for S. superciliaris and 3.381 for S. reevesae. The data will be helpful in further research regarding these species in the upper Yangtze River Basin.     

Length–weight relationships of three freshwater fish species from Rupnaryan and Kangsabati River,West Bengal,India

The length–weight relationships (LWRs) of three freshwater fish species from the Kangsabati and Rupnaryan river in West Bengal, India are presented, namely as Amblypharyngodon microlepis (Bleeker, 1853), Parambassis lala (Hamilton, 1822) and Macrognathus aculeatus (Bloch, 1786). Gill‐nets (mesh sizes with 0.5 cm–4 cm), cast‐nets (up to 1 × 1 cm mesh size with up to 4.0 m² area) and scoop‐nets (0.3 × 0.3 cm and 0.5 × 0.5 cm mesh size) were used from January, 2017 to April, 2018. Sampling was done every 15 days during this period. The value of parameter “b” ranged from 2.751 to 2.895 with highly significant correlations (r² > 0.95).     

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 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 relationships of four freshwater fishes from the Geoje‐island in South Korea

The length–weight relationships (LWRs) for four freshwater fish species in catchment area of Geoje‐island, South Korea, were analyzed. Fish samples were collected quarterly using scoop‐nets (5 mm mesh size), casting nets (7 mm mesh size) from 2016 to 2017. LWRs data for three of these species have not yet been listed in FishBase.     

Length‐weight relationships (LWRs) of four freshwater fish species from the Brahmaputra and Barak river basins,northeast India

The present study describes the length‐weight relationships (LWRs) were determined for four fish species, collected from the Brahmaputra and Barak river basins in northeast India using cast nets (2.5 × 1 m; 10–15 mm mesh size) and gillnets (30 × 0.9 m; 5–10 mm mesh size), from June 2016 to July 2017. The b values in LWRs were determined as 2.70 for Badis tuivaiei Vishwanath & Shanta, 2004, 2.93 for Canthophrys gongota (Hamilton, 1822), 2.62 for Glyptothorax botius (Hamilton, 1822), and 3.22 for Gogangra viridescens (Hamilton, 1822).     

Length–weight relationship of three Cynoglossus species (C. puncticeps,C. lingua and C. lida) from Chilika lagoon,India

The present study provides length–weight relationship (LWR) of three fish species, Cynoglossus puncticeps (Richardson, 1846), Cynoglossus lingua Hamilton, 1822 and Cynoglossus lida (Bleeker, 1851) of family Cynoglossidae from Chilika lagoon (19°28′–19°54′N; 85°05′–85°38′E), India. A total of 147 specimens were sampled during March, July and October of 2017 from screen barrier nets (mesh 14 mm to 26 mm) locally called khonda jal operated by local fishermen. The estimated b values derived from the data sets as follows: 3.12 for C. puncticeps, 3.09 for C. lida, and 2.88 for C. lingua.     

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 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 three fish species from the Arial Khan River,an outlet of the river Padma,Bangladesh

The present study narrated the length–weight relationships (LWRs) of three fish species Salmophasia sardinella (Valenciennes, 1844), Amblypharyngodon microlepis (Bleeker, 1853) and Macrognathus aral (Bloch & Scheider, 1801) from the Arial Khan River, a south‐eastward outlet of the river Padma, Bangladesh. Fish samples were collected monthly basis from fishermen who used cast nets (mesh size <0.5 cm) and set bag nets (mesh size 0.5 cm) for catching fish species from January to December, 2016. The growth coefficient b in LWRs were 3.004, 3.001 and 2.936 for M. aral, S. sardinella and A. microlepis, respectively.