Length–weight relationships of 20 fish species from Bahía de Matanchen,in the southeast Gulf of California,Mexico

Length–weight relationship (LWR) parameters were determined for 20 fish species belonging to 14 genera and seven families. The fishes were collected monthly (May 2013 to February 2014) by soft‐bottom trawls in Bahía de Matanchén, southeast of the Gulf of California. Sizes ranged between 5.5 and 36.0 cm total length (TL) and weighed between 1 and 901 g. The allometric coefficient (b) of the LWR varied from 2.638 for Chloroscombrus orqueta to 3.668 for Neopisthopterus tropicus. This is the first report of LWR estimations for 15 of the species.     

Length-Weight Relationships for freshwater fishes from streams of the Atlantic Rainforest,State of Paraná, Brazil

This study reports the Length-Weight Relationships (LWR) for 10 freshwater fish species sampled in the Atlantic Rainforest, Southern Brazil. Sampling was conducted between 2016 and 2017, in nine streams, using electrofishing. Collected fishes were fixed in formalin, and thus some shrinking was unavoidable. The values of parameter b of the LWR (W = aL^b) ranged between 2.5 and 3.5. We report for the first time the LWR for seven species: Geophagus iporanguensis, Isbrueckerichthys duseni, Hypostomus interruptus, Kronichthys lacerta, Chasmocranu lopezi, Astyanax lacustris e Neoplecostomus ribeirensis. We highlight the importance of the LWR data in supporting further studies on fish stocks and environment in the Atlantic Rainforest, thereby contributing to the database needed to develop fisheries management and maintenance of ecosystem services.     

Length–weight and length–length relationships and length at first maturity for freshwater fish species of the Salto Santiago Reservoir,Iguaçu River Basin,Brazil

Length‐weight (LWR) and length‐length (LLR) relationships were estimated for 20 species and lengths at first maturity (L₅₀) for six species of freshwater fishes caught in the Salto Santiago Reservoir, Iguaçu River Basin, Brazil. In nine species significant differences were found in the LWR between sexes. Average b‐value for species with no differences between sexes in LWR was 3.12 (SE = ±0.05). Average b‐value in LLR was 0.823. First references on LWRs and L₅₀ are presented for 13 and four fish species, respectively, as well as the new maximum total lengths for eight species.     

Length–weight relationships for 11 species at three small hydropower plants on the Sapucaí‐Mirim River (Grande River basin,Brazil)

This paper presents length–weight relationships (LWR) for 11 freshwater fish species from the Sapucaí‐Mirim River, a tributary of the Grande River basin, São Paulo, Brazil. The specimens were captured in quarterly samplings between March 2011 and December 2014, using gillnets of mesh size: 1.5–9.0 cm between knots. The present study adds new information for the maximum length of seven species, and presents new LWR records for four species.     

Length‐weight relationships of six native and one introduced species in small perennial watercourses of the Chocó region of Ecuador

This study estimated the length‐weight relationship (LWR) of seven species (six native species and one introduced species) in two small perennial watercourses of the Chocó region of Ecuador. Specimens were collected bimonthly with two different fishing methods between August 2016 and July 2017 (Seine net: 46 × 21.20 m, 3 mm mesh size and casting net: 2.10 m radius, 10 mm mesh size). This is the first report of the LWR and a new report on maximum length for two endemic species (Eretmobrycon ecuadorensis and Andinoacara blombergi). The intercept (a) of the LWR ranged from 0.0124 to 0.0316 and the slope (b) ranged from 3.03 and 3.16. The LWRs are useful and, in connection with the collection of other key data on fish biology and the environment they can contribute to management and conservation of the local inland fisheries.     

Length–weight relationships for seven fish species of the Napo River,Upper Amazon,Peru

Length–weight relationships (LWR) were estimated for seven fish species from the Napo River and its main tributaries, Arabela and Curaray rivers, Amazon basin, Peru. A total of 652 specimens were sampled between 2012 and 2014 using seines and gillnets. This study reports new maximum total length for four species and new LWR and maximum total weight records for three and five species, respectively.     

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 15 fish species of the Xun Jiang River in Guangxi,China

Length–weight relationships (LWRs) were estimated for 15 species belonging to four orders and five families from the Xunjiang River, China. Exponent b varied from 2.364 to 3.634, and r² values varied from .914 to .991. This is the first LWR report in the area for these species, seven species of which are published for the first time.     

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

Length‐weight relationships (LWR) for three cyprinid fish species collected from the headwaters of the Nujiang River in Tibet, China, were determined. The values of parameter b in the LWR equations were estimated as 2.54 for Schizopygopsis thermalis, 3.3 for Ptychobarbus kaznakovi, and 2.74 for Schizothorax nukiangensis, respectively. These are the first LWR records for the three species.     

Length‐weight relationships of seven fish species from Jequitinhonha River basin,southeastern Brazil

The present study established the length‐weight relationships (LWR) for seven fish species from Jequitinhonha River basin, a Brazilian coastal drainage, collected with gillnets (3 to 16 cm) between 2011 and 2016. For the LWR, standard length and total weight were used. The allometric coefficient b varied from 2.66 to 3.26. These results provide biological data for a region of extreme biogeographical importance that is suffering serious environmental disturbances.     

Length‐weight relationship of freshwater fish,Puntius shalynius Yazdani and Talukdar (Cypriniformes: Cyprinidae), in Meghalaya,India

The present investigation gives the length‐weight relationship (LWR) of Puntius shalynius in Meghalaya, India. The samples for the study were collected from Umiam river. The value of the exponent ‘b’ in the LWR was less than 3, with 0.885 for males and 1.616 in females. This shows that the species exhibit allometric growth pattern. There was no difference in LWR between sexes and seasons.     

Length–weight relationships of wild fish captured at the mouth of Río Verde,Oaxaca, México and connected lagoons (Miniyua,El Espejo,Chacahua and Pastoría)

Length–weight relationships (LWR) were estimated for 34 fish species belonging to 25 genera and 17 families, specimens were collected near the mouth of the Río Verde, Oaxaca, Mexico. All r² values are statistically significant (P > 0.0001). The values of ‘b’ ranged from 2.55 and 3.3, within the usual range (2.5–3.5). This study provides the first LWR references for six species, and new maximum length records for eight species.     

A Bayesian approach for estimating length‐weight relationships in fishes

A Bayesian hierarchical approach is presented for the estimation of length‐weight relationships (LWR) in fishes. In particular, estimates are provided for the LWR parameters a and b in general as well as by body shape. These priors and existing LWR studies were used to derive species‐specific LWR parameters. In the case of data‐poor species, the analysis includes LWR studies of closely related species with the same body shape. This approach yielded LWR parameter estimates with measures of uncertainty for practically all known 32 000 species of fishes. Provided is a large LWR data set extracted from www.fishbase.org , the source code of the respective analyses, and ready‐to‐use tools for practitioners. This is presented as an example of a self‐learning online database where the addition of new studies improves the species‐specific parameter estimates, and where these parameter estimates inform the analysis of new data.     

Length‐weight relationship of Pseudophoxinus alii Küçük,in Lake Yamansaz,a coastal freshwater lake in Antalya,Turkey

This study describes the length–weight relationship (LWR) of Pseudophoxinus alii from the Yamansaz Lake, a coastal freshwater lake in Antalya, Turkey. A total of 105 specimens were obtained using a variety of nets between April 2007 and March 2008. Total lengths ranged from 3.4 to 14.3 cm. The length–weight relationship showed a positive allometric growth (b = 3.012; R² = 0.988). The study presents the first reference on LWR for this threatened species. The results also indicate a new maximum total length not previously reported in the international literature.     

Length–weight relationships of fish species associated with the mangrove forest in the southwestern Terminos Lagoon,Campeche (Mexico)

Length–weight relationships (LWR) were calculated for 18 species representing 11 families of fishes. A total of 958 fish specimens from the southwestern Terminos Lagoon, Campeche (Mexico), several of which had none or few LWRs available in FishBase, were sampled (except December) using a shrimp otter trawl net from September 2003 to August 2004. Sample sizes ranged from seven Mugil curema and Archosargus probatocephalus individuals to 250 Eugerres plumieri.     

Length–weight relationships of four fish species from the upper Paraná River basin,Southeastern Brazil

Here the length–weight relationships (LWR, hereafter) of Pareiorhina pelicicei, Trichomycterus candidus, T. pirabitira, and T. piratymbara are provided. Samples of each species were collected between April and July 2017 with a hand net (1.5 mm mesh) in three sites from the upper Paraná River basin, Southeastern Brazil. These results increase knowledge about the LWR of Neotropical freshwater fish.     

Length–weight relationships of two cyprinid fish species,Crossocheilus latius (Hamilton, 1822) and Garra gotyla gotyla (Gray, 1830) from the Ganga River Basin,India

This study provides length–weight relationship (LWR) information for two fish species (family Cyprinidae), Crossocheilus latius (Hamilton, 1822) and Garra gotyla gotyla (Gray, 1830), from a tributary of the Ganga River Basin, India. Both species had no previous LWR estimates as per Fishbase 2014.     

Length–weight relationships of five Gobiidae species from Bohai Bay,China

Length–weight relationships (LWR) for five Gobiidae species collected by trawl net in Bohai Bay, China, were determined. Parameter b in the LWR was 2.871, 2.664, 2.901, 3.237 and 2.882 for Amblychaeturichthys hexanema, Synechogobius ommaturus, Odontamblyopus rubicundus, Tridentiger barbatus and Paratrypauchen microcephalus, respectively. This is the first report in FishBase for the fitted LWRs of three of the Gobiidae species mentioned above.     

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 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.