Length–weight and length–length relationships for nine species of the genus Paracobitis (Nemacheiliidae) in Iran

Length–weight (LWR) and length–length (LLR) relationships were estimated for 330 specimens from nine Paracobitis species in 11 localities throughout Iran. All fish were collected upon occasion by electrofishing throughout Iran from July 2010 to October 2016. These represent the first reports of LWR data for eight species including: Paracobitis atrakensis, P. hircanica, P. longicauda, P. molavii, P. persa, P. rhadinaeus, P. smithi and P. vignai and first LLR data for all species. A new maximum length is reported for P. malapterura. Four of these species are endemic and five species are native to Iran. The length–weight parameter b ranged from a minimum of 2.74 for P. atrakensis to a maximum of 3.01 for P. longicauda, with regression coefficients (r²) ranging from 0.96 to 0.99. All LLRs were highly significant (r² > .96).     

Length–weight relationship for ten native fish species captured in the streams of the Contas River basin,Northeastern Mata Atlântica freshwater ecoregion,Brazil

This work describes the length-weight relationship (LWR) of ten fish species from the Contas River Basin, Bahia State, Brazil. Sampling was conducted quarterly between November 2012 and November 2013 in 18 wadeable streams (nine in the Diamantina Plateau, Caatinga biome, and nine in the Atlantic forest biome). The fishes were caught using electrofishing (800V DC) and hand nets (2.0 mm mesh size) in 50 meters stretch by the sample unit. Collected fishes were fixed in formalin and preserved in alcohol, and thus some shrinking probably occurred. The values of parameter b of the LWR (W = aL^b) ranged between 2.763 and 3.267. It is the first record of LWR parameters for nine species, all endemic to Northeastern Mata Atlântica freshwater ecoregion (NMAF). Moreover, new maximum lengths are presented for five 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 of the genus Alosa (Clupeoidei: Clupeiformes: Clupeidae) along the southern Caspian Sea coast

Length–weight (LWR) and length–length (LLR) relationships were estimated for four shad species of the genus Alosa, reported from along the southern Caspian Sea coast, north of Iran in a study from March 2014. Two of these species are endemic to the Caspian Sea. The length–weight parameter b for these species ranged from 2.99 to 3.24, with regression coefficients (r²) ranging from 0.91 to 0.99. All LLRs were highly significant (r² > 0.96).     

Length–weight relationships of six fish species from the upper reaches of the Yangtze River,southwest China

Length–weight relationships (LWRs) were determined for six endemic fish species [Glyptothorax fokiensis (Rendahl, 1925), Lepturichthys fimbriata (Günther, 1888), Liobagrus marginatus (Günther, 1892), Percocypris pingi (Tchang, 1930), Pseudobagrus pratti (Günther, 1892) and Sinibotia superciliaris (Günther, 1892)] from the Pan Zhihua reach of the Jinsha River, which is located in the upper reaches of the Yangtze River, southwest China. Samples were obtained between May 2004 and April 2012 using various types of fishing gear and electroshock fishing techniques. For each species, the sample size, length range, weight range, LWR, 95% confidence intervals of a and b, and coefficient of correlation were determined. Values of b were between 2.306 for P. pratti and 2.934 for P. pingi, and r² values ranged from 0.952 for G. fokiensis to 0.995 for P. pingi. Prior to this study, the LWRs for three of these endemic species were unknown.     

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 and length–length relationships of three Blenny species from the Persian Gulf and the Gulf of Oman

The present study provides the length–weight and length–length relationships information (LWR & LLR) for three Blenny species; Antennablennius adenensis from the coast of Larak Island in the Persian Gulf and Istiblennius pox and Omobranchus mekranensis, which were captured in the coasts of Chabahar city in the Gulf of Oman, Iran. Total length (TL) and standard length (SL) were determined as well as weight. Specimens were collected occasionally in summer 2017 and winter 2018 by Hand net. The length–weight parameter b for these species was 2.84, 3.29 and 3.06 respectively with a high coefficient of determination (r² ≥ 0.95). All LLRs were highly correlated (r² > 0.99). All three species had no previous report for LWR and LLR estimates in FishBase.     

Length–weight relationships of 11 deep‐sea fishes from the western Bay of Bengal and Andaman waters,India

Length–weight relationships (LWRs) are presented for 11 deep‐sea fishes caught in the western Bay of Bengal and Andaman waters during August 2010 using a 38 m high speed demersal trawl II (HSDT II, crustacean version, codend mesh size 40 mm) and a 45.6 m Expo model demersal trawl (codend mesh size 30 mm). The b values ranged from 2.34 to 3.3 and the coefficient of variation (r²) ranged from .82 to .98. LWR estimates of eight deep‐sea fishes are provided for the first time. The estimated LWR values were compared with the Bayesian LWR estimates available in FishBase, based on models developed to improve the accuracy and predictability of species‐specific growth parameters of data‐poor species.     

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 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 relationship of six notothenioid species from sub‐Antarctic waters (Beagle Channel,Argentina)

This study presents length‐weight relationships (LWR) for six species of fishes of the Suborder Notothenioidei that inhabit the sub‐Antarctic waters of the Beagle Channel (Argentina). These species represent five of the nine families of this Suborder. The specimens belong to historical fish collections in the area (from 1987 to 1990) using gill and trammel nets. All species but Eleginops maclovinus had no previous LWR estimates. The coefficient of determination (r²) ranged from 0.91 to 0.99 and b values ranged from 2.74 to 3.2. Harpagifer bispinis was the only species with a b value lower than three. This information is useful to predict the weight from the length data and to provide insights into the ecology of sub‐Antarctic nototheniod fish.     

Length–weight and length–length relationships for 11 species of the genus Alburnoides Jeitteles, 1861 (Cyprinidae) from Iran

Length–weight (LWR) and length–length (LLR) relationships were estimated for 11 Alburnoides species from 15 localities throughout Iran. These represent the first reports of LWR and LLRs data for 10 species, including: Alburnoides coadi (40 specimens), A. damghani (30), A. eichwaldii (110), A. holciki (30), A. idigensis (113), A. namaki (30), A. nicolausi (30), A. parhami (30), A. qanati (30) and A. tabarestanensis (30) and first LLR data for A. samiii. Nine of these species are endemic and two are native to Iran. The length–weight parameter b for these species ranged from a minimum of 2.94 for Alburnoides nicolausi to a maximum of 3.37 for Alburnoides parhami, with regression coefficients (r²) ranging from 0.91 to 0.99. All LLRs were highly significant (r² > 0.96).     

Composition and length‐weight relationships of fish species in Lake Erhai,southwestern China

Length–weight relationships (LWRs) are described for 23 fish species (five indigenous species and 18 exotic species) in Lake Erhai, a plateau deep lake located in southwestern China. Four different types of fishing gear were used in order to include all possible length ranges from 2009 to 2012. Results show that the exponent b ranged from 2.72 to 3.79. The length of the growth inflection point between juveniles and females of Pseudorasbora parva and Micropercops swinhonis coincides with the length at which 50% of the females are sexually mature, respectively. The LWRs of P. parva and M. swinhonis are affected by sexual dimorphism, and Hemiculter leucisculus shows significant differences between juveniles and females. In addition, the first LWR records for nine species are provided in this study.     

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 relationship of 74 fish species caught in the continental coast of Ecuador

This work analysis the length-weight relationships for fish species captured by artisanal fishery along the continental coast of Ecuador. Fishermen used the following fishing gear: beach seine nets (5.1–31.8 mm), shrimp trawl nets (21.8–31.8 mm) and bottom gill nets (54.1–203.2 mm). Sampling took place during the years 2012 and 2014. Frequency of sampling was monthly, and it was completed systematically from Southern toward Northern Provinces. Length-weight relationship (LWR) was realized by the power model (y = a × x^b), for species with a bivariate dataset >70. A total of 59 commercial and 15 non-commercial species were registered. For 74 species, our analysis including a higher total length not reported in LWR estimates previously. The determination coefficient (r²) value was always above 0.95.     

Length–weight relationships for three fish species from the middle and lower reaches of the Jinsha River,China

This paper provides the length–weight relationships of three fish species from the middle and lower reaches of the Jinsha River, China. Samples were obtained seasonally during 2013~2016 using fishing gear (drift gillnets and di long) and electroshock fishing techniques (backpack electrofishing control unit powered by 12 V). For each species, the sample size, length range, weight range, LWR, 95% confidence intervals of a and b, and coefficient of correlation were determined. Length–weight relationship (LWR) for one species was unknown to FishBase and new maximum lengths were recorded for two species.     

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 dominant fish species from Caxiuanã National Forest,Eastern Amazon,Brazil

The present work presents parameters of the length–weight relationships (LWR) for 12 species of freshwater fish from rivers within the Caxiuanã National Forest, Eastern Amazon. Data coverage include the main taxonomic groups in the sampling area: Characiformes: Acestrorhynchidae, Anostomidae, Curimaridae, Erythrinidae, Hemiodontidae; Siluriformes: Auchenipteridae; Perciformes: Sciaenidae. LWR parameters are estimated for the first time for five species: Leporinus affinis, Bryconops melanurus, Pygopristis denticulata, Serrasalmus gouldingi and Triportheus albus. Relative growth patterns were evenly distributed among species, one‐third showing negative allometry (b < 3; n = 4), isometry (b = 3; n = 4) or positive allometry (b > 3; n = 4).     

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.