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 and length–length relationships and seasonal condition factors for two mudskippers,Periophthalmus modestus (Cantor, 1842) and P. magnuspinnatus (Lee,Choi & Ryu, 1995) (Gobiidae), on tidal flats of Korea

Presented are the length–weight and length–length relationships and condition factors for two mudskippers, Periophthalmus modestus and Periophthalmus magnuspinnatus, on the tidal flats of Korea. Values of the exponent b, estimated by nonlinear least squares from weight and length data, were 3.031 for P. modestus and 3.044 for P. magnuspinnatus. All relationships between total and standard length were linear (r² > 0.974). The condition factors were significantly higher during the post‐spawning season than at other times for both species.     

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 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 and length–length relationships of three fish species (Cyprinidae) from Chahnimeh reservoirs,Zabol, in eastern Iran

Length–weight (LWR) and length–length (LLR) relationships was estimated for three fish species collected in Chahnimeh reservoirs located in the city of Zabol, Iran. The values of the parameter slope (b) in the length–weight relationship were determined 2.45 for Crossocheilus latius, 2.97 for Schizocypris altidorsalis and 3.14 for Schizothorax zarudnyi. The relationships between TL, FL and SL were all linear (for all cases: r² > 0.93).     

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).     

Length–weight and length–length relationships of five fish species in the Atrai River,Dinajpur, Bangladesh

A total of 502 specimens were obtained during monthly samplings from July to December 2015, by fishermen using seine nets, gillnets and cast nets. Length–weight (LWRs) and length–length (LLRs) relationships were estimated for five fish species collected from the Atrai River in the northwestern region of Bangladesh. The values of slope (b) in LWRs (r² > .913, p < .001) were determined as 2.899 for Aspidoparia jaya, 3.059 for Gagata cenia, 3.004 for Gagata youssoufi, 2.755 for Salmophasia bacaila, and 3.222 for Salmophasia phulo, respectively. The linear relationships in TL, FL and SL were highly correlated (for all cases: r² > .897, p < .001). No previous information on LWRs (except for G. cenia) and LLRs (except for S. bacaila) of these selected species were found in FishBase.     

Length–weight and length–length relationships of three fish species from the Heihe River,northwest China

Length‐weight (LWRs) and length–length (LLRs) relationships are reported for three fish species belonging to two families and two genera from the Heihe River, northwest China. Fish samples were collected using trap nets (mesh size 1 cm) in May and December of 2016, and April and October 2017. Standard length (SL) and total length (TL) for each individual were measured to the nearest 0.1 cm by digital slide caliper and each body weight (BW) was measured to an accuracy of 0.1 g using digital balance. The b‐values for LWRs varied from 2.580 to 3.164 (r² > .956). The results further indicated that the LLRs were highly correlated (r² > .991; p < .01). This study presents the first references on LWRs for Gymnocypris chilianensis and Triplophysa hsutschouensis, and LLRs for G. chilianensis, Triplophysa leptosoma and T. hsutschouensis. This biometric data and their relationships are relevant to the management and conservation of local fishes and fisheries.     

Length–weight and length–length relationships of fish species from the Chi River,northeastern Thailand

The relationships of total length (TL), fork length (FL) and standard length (SL) are presented for four fish species and the relationships between TL and wet weight for 23 fish species from the Chi River in northeastern Thailand. All length–length relationships were linear (r² > 0.95). Slope (b) of the length–weight relationships showed values between 2.5073 and 3.4896.     

Length–weight and length–length relationships of five fish species from the Dadu River and its tributaries,southwest China

Length‐weight (LWRs) and length–length (LLRs) relationships are reported for five fish species belonging to two families and five genera from the Dadu River and its tributaries, southwest China. In total, 605 specimens were collected by electrofishing and gillnets (mesh size ranging from 1.5 to 3.5 cm) in May and October 2013, May and October 2014, May and November 2015, and April and October 2016. The b‐values for LWRs varied from 2.571 to 2.952 (r² > .915). The results further indicated that the LLRs were highly correlated (r² > .978; p < .01). The two LWRs, five LLRs, and two maximum lengths are presented to FishBase for the first time. This biometric data and their relationships are relevant to the management and conservation of local fishes and fisheries.     

Length–length and length–weight relationships of fish species from the Lake Eyre Basin,Australia

The Lake Eyre Basin in central Australia is one of the world's last unregulated dryland river systems. To facilitate future research in this area, the relationships between total length, standard length, and wet weight for 10 widespread, large‐bodied freshwater fish species are presented. All linear relationships were strong (r² > 0.90) and values of the exponent b of the length–weight relationships ranged from 2.786 to 3.336. These results provide novel baseline data for species in this area.     

Length–weight and length–length relationships of four fish species from the middle reaches of the Minjiang River,southwest China

Length–weight (LWR) and length–length (LLR) relationships are reported for Glyptothorax fokiensis (Rendahl, 1925), Microphysogobio kachekensis (Oshima, 1926), Pseudobagrus brevicaudatus (Wu, 1930), and Sinibrama taeniatus (Nichols, 1941) from the middle reaches of the Minjiang River and its tributaries, Sichuan Province, in southwest China. A total of 675 specimens were obtained between 2013 and 2016 using various types of fishing gear and electroshock fishing techniques. Standard length and total length for each individual were measured by digital slide caliper and each body weight was taken by digital balance. The b‐values for LWRs varied from 2.617 to 3.249 (r² > .954), and the LLRs were highly correlated (r² > .983; p < .01).     

Length–weight and length–length relationships of seven freshwater fish species from the Daning River,a tributary of the Yangtze River,southwest China

This study determined the length–weight relationships (LWRs) and length–length relationships (LLRs) of seven freshwater fish from the Daning River, a tributary of the Yangtze River, southwest China. Specimens were collected between July 2016 and July 2017 using drift gill nets (mesh size 1, 2 and 3 cm), cage net (0.5 cm mesh size) and electroshock fishing techniques quaterly. Parameter b values of LWRs ranged from 2.647 to 3.276 (r² > .963) and b values of LLRs ranged from 1.091 to 1.213(r² > .985). Six new LLRs and seven new maximum length data are presented. The biometric data and their relationships are relevant to Fishers science to supplement other data sets needed for fisheries management.     

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 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.     

Size at first sexual maturity,fecundity, length–weight and length–length relationships of Puntius sophore (Cyprinidae) in Bangladeshi waters

The present study describes the size at first sexual maturity, fecundity, length–weight (LWRs) and length–length relationships (LLRs) of the pool barb, Puntius sophore, using data obtained from different geographical locations in Bangladesh. A total of 905 specimens were caught by traditional fishing gear from March 2010 to February 2011. Additionally, a total of 121 females were collected from a commercial catch of the Padma River during June–July 2011 to estimate size at first maturity and to determine fecundity. Total length (TL), fork length (FL) and standard length (SL) were measured with digital slide calipers. Individual body weights (BW) were determined for all specimens, and gonad weights (GW) from 121 females were weighed to an accuracy of 0.001 g. The female gonadosomatic index (GSI) was calculated as [GSI (%) = (GW/BW) × 100]. Female size at first maturity was estimated using GSI and TL as indicators, and estimated as 5.00 cm TL in the Padma River. Specimens larger than 5.00 cm TL were used to determine fecundity. Mean total fecundity was 5300 ± 2700, ranging from 1580 to 16590. A positive exponential correlation was recorded between total fecundity and total length (r² = 0.421). Relative fecundity ranged from 466 to 4036 (mean 1100 ± 580) in the Padma River. The LWR of pooled data for sexes combined was estimated as BW = 0.0155 TL^2.98 as ancova revealed no significant differences in LWRs between rivers (P > 0.05). All LLRs were highly correlated (r² > 0.983; P < 0.001), and ancova analyses further indicated that LLRs did not differ between rivers (P > 0.05). These results will help in further studies on the population assessment of the species.     

Length–weight and length–length relationships for two gobiids from the Anzali Wetland,in the southern Caspian Sea basin

Length–weight (LWR) and length–length (LLR) relationships were estimated for specimens of two gobiid species collected from the Anzali Wetland and its related streams in the southern Caspian Sea basin, in August 2017. These represent the first reports of LWR and LLR data for Rhinogobius cf. similis Gill, 1859 (37°28′13″N, 49°20′33″E; 50 individuals) and Proterorhinus nasalis (De Filippi, 1863) (36°54′10.89″N, 53°48′48.33″E; 30 individuals) from the Wetland. A new maximum length is reported for P. nasalis. The length–weight parameter b for these species ranged a minimum of 2.99 for Rhinogobius cf. similis to a maximum of 3.04 for P. nasalis with regression coefficients (r²) ranging from .95 to .97. All LLRs were highly significant (r²>.96).     

Length–weight and length–length relationships of five threatened fish species from the Jamuna (Brahmaputra River tributary) River,northern Bangladesh

The small indigenous species, namely Ailiichthys punctata (Day, 1871), Botia lohachata (Chaudhuri, 1912), Chanda nama (Hamilton, 1822), Laubuca laubuca (Hamilton, 1822) and Mystus cavasius (Hamilton, 1822), comprise an important component of riverine fisheries of Bangladesh. This study describes the length–weight relationships (LWRs) and length–length relationships (LLRs) of five threatened fishes from the Jamuna River, a distributary of the Brahmaputra River in northern Bangladesh. A total of 919 specimens from five species in five families used for this study were caught by traditional fishing gear, March 2010 through February 2011. The allometric coefficient (b) of the LWRs indicated negative allometric growth in A. punctata, B. lohachata, and C. nama (b < 3.00), but positive allometric growth in L. laubuca and M. cavasius (b > 3.00). Furthermore, the LLRs were highly correlated (r² > 0.978; P < 0.001). This study presents the first reference on LWRs and LLRs for these threatened species in Bangladesh. The results would be useful for sustainable management and conservation of the limited stocks in the Brahmaputra River ecosystem.     

Length–weight and length–length relationships of four species of genus Pethia and genus Puntius from wetlands of Lakhimpur district,Assam, India

Length–weight relationships (LWR) and length–length relationships (LLR) were estimated for four species, namely, Puntius sophore (Hamilton, 1822), Puntius chola (Hamilton, 1822), Pethia ornatus (Vishwanath & Laisram, 2004) and Pethia ticto (Hamilton, 1822) collected from different wetlands of Lakhimpur, Assam. The values of the parameter slope (b) in the LWR were 3.30 for Puntius sophore, 3.22 for Puntius chola, 2.61 for Pethia ornatus and 3.27 for Pethia ticto. The relationships among TL, FL and SL were all linear (r² > 0.95).     

Length–weight and length–length relationships for six flounder species (Pleuronectiformes) from the eastern coast of Korea

The relationships between total length and wet weight and between total length and standard length are presented for six flounder species from the eastern coast of Korea between 2011 and 2012: Paralichthys olivaceus (Temminck & Schlegel, 1846), Cleisthenes pinetorum (Jordan & Starks, 1904), Glyptocephalus stelleri (Schmidt, 1904), Platichthys stellatus (Pallas, 1787), Pseudopleuronectes herzensteini (Jordan & Snyder, 1901), and Pseudopleuronectes yokohamae (Günther, 1877). The values of exponent b, estimated using nonlinear least squares of weight and length data, ranged from 3.076 to 3.469. All relationships between total length and standard length were linear (all r² > 0.948). Fisheries scientists apply these size conversions (total length calculated from standard length) to understand several aspects of the population dynamics.