Length‐weight and length‐length relationships of the invasive red lionfish [Pterois volitans (Linnaeus, 1758): Scorpaenidae] in the Parque Nacional Arrecife Alacranes,Southern Gulf of Mexico

Described are the length–weight (LW) and length–length (LL) relationships of the Indo–Pacific, red lionfish [Pterois volitans (Linnaeus, 1758): Scorpaenidae] – an invasive fish introduced into the coral reefs of the Western Atlantic. Volunteer diver‐fishers speared a total of 455 red lionfish (range 9–35 cm TL) from July 2010 to December 2011 in the Parque Nacional Arrecife Alacranes, off the northern coast of the Yucatan Peninsula, Mexico. The LWR obtained in the combined data was W = 0.104TL^3.309.     

Length–weight relationships of four small indigenous fish species from an inland artisanal fishery,Bangladesh

This study reports the length–weight relationships (LWRs) of four small indigenous species, Trichogaster lalius (Hamilton, 1822), Nandus meni (Hossain & Sarker, 2013), Lepidocephalichthys annandalei (Chaudhuri, 1912) and Botia dario (Hamilton, 1822) collected between July 2015 and August 2016 from fishermen's catches landed in an inland fish landing center, northeastern Bangladesh. In the study, a new maximum total length (TL) is given for L. annandalei and LWRs of three species T. lalius, N. meni and L. annandalei for the first time in FishBase. Estimated LWRs were W = .014 TL^3.17, (r² = .982) for T. lalius, W = .006 TL^3.38, (r² = .961) for N. meni, W = .004 TL^3.27, (r² = .965) for L. annandalei and W = .020 TL^2.87, (r² = .978) for B. dario.     

Growth characteristics of Uranoscopus scaber Linnaeus 1758, inhabiting the Iskenderun Bay (Northeastern Mediterranean)

This study aimed to determine the age and some growth characteristics of Atlantic stargazer (Uranoscopus scaber) from Iskenderun Bay (Northeastern Mediterranean). For this purpose, a total of 150 Atlantic stargazer ranging in size from 9.1 to 28.0 cm in total length (weight: 11.7–345.7 g) were collected as by-catch from a commercial trawl fishing boat at a depth of 80–100 m between May 2015 and January 2016. The bottom trawl gear used was equipped with a 44 mm stretched mesh size net at the cod-end. The percentage of females and males were 46.7% and 53.3% respectively. The total length–weight relationships equation with coefficient of determination (R²) were found as W = 0.011*TL^3.131, R² = .9728, for all individuals, W = 0.015*TL^3.021, R² = .9512 for females and W = 0.0102*TL^3.136, R² = .9553 for males. By using the von Bertalanffy equation, the growth parameters of Atlantic stargazer were estimated to be L_∞ = 42.35 cm, k = 0.098, t₀ = −1.8474 for all individuals; L_∞ = 36.92 cm, k = 0.138, t₀ = −1.2693 for females and L_∞ = 38.77 cm, k = 0.1, t₀ = −2.334 for males. In this study, age reading was done by two independent readers and index of average percentage error (IAPE) was calculated as 6.1%. The highest condition factor value calculated as 1.81 in the age group 6 and the lowest condition factor value was calculated as 1.48 in the age group 1.     

Length–weight relationships for three fish species from Yalong River in China

This study provides the first report of length–weight relationships (LWRs) for three fish species collected from the Yalong River, one of the tributaries to the upper reaches of the Yangtze River, China. The LWRs of these fish species were BW = 0.0070TL^3.0539 (r² = 0.9662) for Schizothorax wangchiachii, BW=0.0134TL^2.8523 (r² = 0.9676) for Schizopygopsis malacanthus, and BW=0.0143TL^2.9253 (r² = 0.8538) for Euchiloglanis kishinouyei, respectively. Also investigated were the spawning season, absolute fecundity and main food items of the three fish species in the natural environment. In addition, new maximum sizes for the three species are provided.     

Length‐weight relationships of Acanthopagrus longispinnis (Valenciennes, 1830), Raconda russeliana (Gray, 1831) and Coilia neglecta (Whitehead, 1967) from the Bay of Bengal coast,Bangladesh

Current study reports the length‐weight relationships (LWRs) of three marine fish species collected from the fishermen catches covering three seasons i.e., rainy, autumn and winter between June, 2016 and February, 2017. Fishermen caught the species using beach seine net (3.5 cm mesh size) and set bag net (0.5 cm mesh size) up to 200 m far away from the shoreline. The LWRs for fish species were W = 0.0180TL^3.192 for A. longispinnis, W = 0.0109TL^2.971 for R. russeliana and W = 0.0098TL^2.942 for C. neglecta with their r² values of 0.971, 0.962 and 0.997, respectively.     

Length–weight,length–length relationships and feeding habits of wild Indus Mahseer,Tor macrolepis,from Attock,Pakistan

In this study the length–weight (LWR) and length–length relationships (LLR) were carried out for Indus Mahseer, Tor macrolepis, from the Haro River and Nalah Kala, Attock, Pakistan. A total of 118 specimens were used to estimate the relationship parameters. The results of LWR (W = a TL^b) from five different sites indicated W = 0.0044 TL^3.14, W = 0.0054 TL^3.08, W = 0.0059 TL^3.21, W = 0.0076 TL^3.12, and W = 0.0107 TL^2.99, respectively, with an overall value of W = 0.0100 TL^2.94. All regressions for LLR were highly significant (P ≤ 0.001), with coefficient of determination (r²) values of > 0.90. All relationships for LWR and LLR were found to be isometric. T. macrolepis is principally a herbivorous bottom feeder, mainly feeding on aquatic plants and algae, supplemented by insects.     

Length–weight relationships of wild and farmed Tor putitora from Pakistan

Length–weight relationships (W = a TL^b) were estimated for wild and farmed Tor putitora obtained from River Korang, Islamabad and Attock District, Pakistan, respectively. The results indicate, W = 0.0171 TL^2.85 for wild and W = 0.1000 TL^2.33 for farmed. Total length ranged from 18.0 to 40.2 cm for male and 31.6 to 37.0 cm for female wild Tor putitora, indicating that the fish are now much smaller. The first reference of length–weight relationships for Tor putitora is provided.     

Length–weight relationship of Rastrelliger brachysoma (Bleeker, 1851) and Rastrelliger faughni Matsui, 1967 from the Andaman Islands,India

This study reports the length–weight relationships (LWRs) of Rastrelliger brachysoma (Bleeker, 1851) and Rastrelliger faughni Matsui, 1967 from Andaman Islands, India. Sample sizes for the two fish species were 78 for R. brachysoma and 57 for R. faughni. Fish collected monthly from Junglighat fish landing center. Fish were captured by commercial ring seine units (mesh size ranging from 2 to 4 cm) between February 2016 and March 2017. LWRs were established as TW = 0.0042TL^3.332 (r² = .989) for R. brachysoma and TW = 0.0096TL^3.022 (r² = .980) for R. faughni.     

A study on age and growth characteristics of spiny gurnard (Lepidotrigla dieuzeidei Blanc & Hureau, 1973), northeastern Mediterranean Sea

This study investigated the age and growth characteristics of spiny gurnard, Lepidotrigla dieuzeidei, from the northeastern Mediterranean. Samples were collected by commercial trawls during the 2012–2013 fishing seasons. A total 1,878 speciments ranged from 7.10 to 15.90 cm total length and 2.28–35.88 g in weight. Female/male ratio was 1.2/1. The total length–weight relationship was W = 0.002 TL^3.579 (r² = .909) for sexes combined, W = 0.0021 TL^3.551 (r² = .914) for males and W = 0.0019 TL^3.602 (r² = .904) for females. Age determination was conducted using the sagittal otoliths. Ages of examined individulas ranged from 3 to 11 years. Total length‐at‐age data were fitted using the von Bertalanffy growth model. Estimated growth functions were TL_t = 18.100 [1?e^{?0.14 (t + 0.63)}] for sexes combined, TL_t = 23.587 [1?e^{?0.08 (t + 1.56)}] for males and TL_t = 16.612 [1?e^{?0.19 (t + 0.15)}] for females.     

Length–weight relationships of three caught flatfish using shrimp trawler in Motaf fishing grounds,Bushehr province (Persian Gulf)

This study provides length–weight relationships (LWRs) for three flatfish species: Cynoglossus bilineatus (Lacepède, 1802), Solea elongata (Day, 1877), and Pseudorhombus elevatus (Ogilby, 1912) from Motaf fishing grounds (latitude 27°00′ to 28°03′N; longitude 51°41′ to 52°11′E), Bushehr province, Iran. A total of 103 fish specimens were collected using shrimp trawler with 40 mm (stretched mesh size) at depths of 10–30 m between August and September 2017. The LWRs for fish species were W = 0.0019L^3.353 for C. bilineatus: W = 0.0093L^3.174 for S. elongata, and W = 0.006L^3.181 for P. elevatus, respectively.     

Growth and length–weight relationships of Sander lucioperca (Linnaeus, 1758) in the Alcántara Reservoir,south‐western Spain: comparison with other water bodies in Eurasia

Growth parameters in pikeperch may be affected by several factors. The purpose of this study was to investigate the growth and length–weight of pikeperch in a reservoir in south‐western Spain and compare the results with previous published data. Age and growth are described for Sander lucioperca from the Alcántara Reservoir (south‐western Spain) from March to October 2009. A total of 285 fish were examined; the ratio of males to females was estimated as 0.78:1 and age ranges as 1–5 years. Total lengths ranged from 16.1 to 52.5 cm. The length–weight relationships were described as W = 0.00 462 TL^3.09 (r = 0.9865) for males and W = 0.00279 TL^3.16 (r = 0.9921) for females. Growth was expressed in length and the von Bertalanffy growth parameters were estimated as L∞ = 92.14 cm, k = 0.09, t₀ = ?1.05 for males and L∞ = 107.72 cm, k = 0.08, t₀ = ?1.16 for females. Growth performance indexes were also estimated as Φ’ = 2.88 for males and Φ’ = 2.96 for females. Differences in growth and length–weight relationships between sexes were not found.     

Length–weight relationship and condition factor of Lepidocephalichthys goalparensis Pillai and Yazdani, 1976 in Assam,India

The present study describes the length–weight relationship (LWR), condition factor (K) and size at first maturity of a cobitid loach, Lepidocephalichthys goalparensis Pillai and Yazdani, 1976 of the family Cobitidae in Assam, India. A total of 716 specimens (males = 324, females = 392) ranging from 3.06 to 7.01 cm total length (TL) and 0.17–2.27 g body weight (BW) were analyzed. The overall value of the allometric coefficient b for the LWR indicated negative allometric growth (<3.00) for both males (2.774) and females (2.993). The size at first maturity (TL₅₀) for female L. goalparensis was estimated to be 5.6 cm TL. The condition factor values ranged from 0.56 to 1.35 in mature females. This is the first time that the biological parameters have been studied in this species.     

Length–weight relationships of two endemic species of Alburnoides nicolausi (Bogutskaya & Coad, 2009) and Alburnus zagrosensis (Coad, 2009) in Houzian River,Lorestan Province,Iran

This investigation prepares the length–weight relationships (LWRs) of two fish species, including Alburnoides nicolausi (Bogutskaya & Coad, 2009) and Alburnus zagrosensis (Coad, 2009) from Houzian River (latitude 33°22′15.20″ to 33°21′31.57″N; longitude 49°44′39.66″ to 49°44′17.67″E), Lorestan province, Iran. Fish specimens were collected monthly using seine net with 5 mm (Stretched) mesh size between April to September 2017. The LWRs for fish species were W = 0.0059L^3.405 (male) and W = 0.0053L^3.494 (female) for A. nicolausi, W = 0.0035L^3.341 (male) and W = 0.003L^3.387 (female) for A. zagrosensis, respectively. The highest value of r² was .931 for male of A. zagrosensis and lowest value was .964 for male of A. nicolausi.     

Length–weight relationships for two marine fish species from the Gulf of Oman: Uranoscopus guttatus Cuvier, 1829 and Lagocephalus inermis (Temminck & Schlegel, 1850)

This study presents the first report of length–weight relationships (LWRs) for Uranoscopus guttatus and Lagocephalus inermis from the Iranian coast on the Gulf of Oman. A wide range of body lengths and weights were obtained using samples from non‐selective trawling surveys. The LWRs obtained were W = 41.408L^3.519 and W = 16.525L^2.847 for U. guttatus and L. inermis, respectively.     

Length–weight and length–length relationships for eight fish species from the Jarrahi River,southwestern Iran

Length–weight and length–length relationships were estimated for eight fish species belonging to three families from the Jarrahi River in southwestern Iran. The study was performed between June 2009 and September 2011. Weight–length relationships were estimated using the logarithmic form of the equation W = aL^b. The b values varied between 2.96 and 3.61 and determined as 3.42 for Alburnus mossulensis Heckel, 1843; 3.33 for Alburnoides idignensis Bogutskaya and Coad, 2009; 2.85 for Barbus grypus Heckel, 1843; 3.61 for Barilius mesopotamicus Berg, 1932; 3.16 for Cyprinion kais (Heckel, 1843); 3.36 for Cyprinion macrostomum Heckel, 1843; 3.27 for Paraschistura nielseni (Nalbant and Bianco, 1998); and 2.96 for Glyptothorax silviae Coad, 1981. This study presents the first LWR and LLR references for these species in the Jarrahi River.     

Length–weight relationship of Hyporthodus haifensis and Mycteroperca rubra (Pisces; Serranidae) from the North‐Eastern Mediterranean Sea,Turkey

Length–weight relationships (LWRs) for Hyporthodus haifensis and Mycteroperca rubra were studied using longlines at depths of 5–150 m, in the Gulf of Antalya, northeastern Mediterranean Sea. Fishing operations were carried out daily with 15 fishing boats. A total of 170 individuals were sampled. The LWR relationships of Hyporthodus haifensis and Mycteroperca rubra were calculated as W = 0.009L^3.142 (r²) = 0.996 and W = 0.0081L^3.0652 (r²) = 0.989 P < 0.05, respectively.     

Length–weight relationships and biological data on guayana pike‐conger Cynoponticus savanna (Bancroft, 1831)

This study presents the first references available for Cynoponticus savanna length–weight relationships (LWR) as well as other biological information, based on its unique population in the South Atlantic Ocean, specifically, Todos os Santos Bay, on the Brazilian central coast. A total of 464 individuals were obtained from artisanal fishing landings between July 2012 and June 2013. Total lengths ranged from 14.5 to 139.6 cm. The length‐weight relationship was BW = 0.716 TL^3.31. Length at first maturity (L_m) was 48.9 cm. Reproduction began gradually in May, reaching a peak around December, with most individuals completing reproduction by January. The gonadosomatic index (GSI) was highest in January (GSI = 0.21) and lowest in March (GSI = 0.024). The male index (GSI = 0.073) was lower than in females (GSI = 0.10) (P < 0.01). This study presents the first population data for C. savanna, which is under threat due to overfishing and habitat loss.     

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.     

Weight–length relationships of 36 fish species from the River Strymon system (northern Greece)

We present 54 weight–length relationships pertaining to 36 fish species, caught in the Greek part of the River Strymon system (northern Greece). The total weight (W) – total length (TL) relationships were estimated using the logarithmic form of the equation W = aTL^b. The exponent b ranged between 2.34 and 3.95, (mean ± SE: 3.16 ± 0.044). For 5 out of the 36 species weight–length parameters are presented for the first time.     

Length‐weight relationships of three estuarine fish species from Bangladesh

The length‐weight relationships (LWRs) of three fish species; Toxotes chatareus (Hamilton, 1822), Datnioides polota (Hamilton, 1822), and Chela cachius (Hamilton, 1822) collected between September 2016 and August 2017 from Tentulia estuary of Bangladesh were analyzed. Fish were caught seasonally using set bag net and cast net with mesh size of 0.5 cm and < 0.5 cm, respectively. LWRs of Toxotes chatareus, Datnioides polota and Chela cachius were calculated as W = 0.0154L^2.926 (r² = .962), W = 0.0149L^3.106 (r² = .992) and W = 0.0109L^2.968 (r² = .981), respectively. The study provides a new maximum total length for Chela cachius.