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 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 Kerala waters,south‐west coast of India

Length–weight relationships (LWRs) of three fish species: Scomberomorus commerson, Alepes vari, and A. kleinii were estimated from Kerala waters, south‐west coast of India. Fish were captured between June 2016 and June 2017 by various gears such as ring seine (8–26 mm mesh size), trawl (30–40 mm cod end mesh size), hook and line (hook number VI–XII), smaller mesh sized drift gill net (26–90 mm) and larger one (120–170 mm) for bigger size fishes. Fish were collected on weekly basis from Cochin Fisheries Harbour (Lat. 09°56′327″N, Long. 76°15′764″E), Munambam Fisheries Harbour (Lat. 10°10′965″N, Long. 76°10′258″E), Kalamukku (Lat. 09°59′924″N, Long. 76°14′564″E) and Chellanam (Lat. 09°47′950″N, Long. 76°16′551″E). All LWRs were significant with r² values ranged from 0.944 to 0.996 and b values ranged from 2.722 to 3.021 (p < .001). In addition, this study provides the information on LWRs and new maximum size for Alepes vari and A. kleinii.     

Length‐weight and length–length relationships of three algae‐scraping cyprinid species from Iran

The study presents length–weight relationships (LWRs) and length–length relationships (LLRs) for three algae‐scraper species; Capoeta coadi from the Kouhrang River (Iran; 32°23′N, 50°08′E) a part of the Tigris drainage basin, Capoeta pyragyi from Cheshmeh Langan River (32°55′N, 50°10′E) a part of Zayanderud River basin and Capoeta umbla from Chooman River (35°57′N, 45°47′E). Fish were sampled by electro fishing (Samus1000; Power Out: 200 watts) in August, September and October 2017. Sampling was carried out each months in sites covering an area of about 100 m² including runs, riffles and pools at a water depth of 10–60 cm. The obtained LWRs and LLRs showed a high level of correlation (r² > 0.99).     

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‐weight and length‐length relationships of Oxynoemacheilus frenatus (Heckel, 1843) and Petroleuciscus esfahani Coad & Bogutskaya, 2010 from the Cheshmeh‐Langan river,Iran

The study presents length‐weight relationships (LWRs) and length‐lenght relationships (LLRs) for two freshwater fish species from the Cheshmeh‐Langan River (Iran; 32°50′N, 50°04′E), a part of the Tigris drainage basin. Fish were sampled by electrofishing (Samus 725M) in August and September 2017. The LWRs and LLRs obtained showed a high level of correlation (r² > .98).     

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 thirteen fish species from the lower Jinsha River,southwest China

Length‐weight and length‐length relationships were investigated for 13 freshwater fish species from the lower Jinsha River, southwest China (from 101°32′49.63″E; 26°35′38.27″N to 104°37′48.14″E; 28°45′59.55″N). Fish were sampled from five sites during 2014 and 2016, using trap‐nets, gillnets (major mesh size: 2–6 cm), longline and electrofishing. Length‐weight relationships for six and length‐length relationships for 12 species are the first report to FishBase, respectively. Moreover, new maximum length for 11 species are also presented to FishBase in this study. All regressions were highly significant (p < .001), with the coefficient of determination r² > .950. These information will be helpful for management and conservation in local fishes and fisheries.     

Length–weight relationships for five fish species from the middle reaches of the Yangtze River,China

Length–weight relationships (LWRs) for five fish species which were captured by trap‐nets and gillnets (major mesh size: 1–10 cm) from the middle Yangtze River, China (29°47′ – 29°26′N; 112°51′ – 113°08′E) were determined in September 2017. These were Acheilognathus hypselonotus (Bleeker, 1871), Culter oxycephaloides Kreyenberg & Pappenheim, 1908, Distoechodon tumirostris Peters, 1881, Sarcocheilichthys nigripinnis (Günther, 1873) and Micropercops swinhonis (Günther, 1873). The LWRs were estimated using the logarithmic form of the formula W  =  a  ×  L^b. The b value ranged from 2.879 for A. hypselonotus to 3.285 for M. swinhonis. LWRs for four fish species and new maximum lengths for three species are presented to FishBase for the first time.     

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 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 and length‐length relationships of Balitora brucei Gray, 1830 and Psilorhynchus balitora (Hamilton, 1822) from the Ranganadi river of Assam,India

The study describes length‐weight relationships (LWRs) and length‐length relationships (LLRs) for two species of fishes, namely Balitora brucei Gray, 1830 and Psilorhynchus balitora (Hamilton, 1822) collected from Ranganadi river in Lakhimpur district of Assam, India for which no LWRs and LLRs are available. While sampling monthly between April 2012 and July 2016, a total of 987 specimens were collected (B. brucei = 427, and P. balitora = 560). Cast nets were used (2 ‐ 10 mm mesh sizes; 2–2.5 m length). The values of the parameter slope (b) in the LWR were determined as 3.194 (male = 3.047 and female = 3.224) for B. brucei and 3.490 (male = 3.480 and female = 3.502) for P. balitora. Present investigation reports new maximum total length for both the fishes.     

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–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 26 fish species from the Yiluo River,a tributary of the Yellow River,China

From February to October 2016, a total of 9,754 fish specimens were collected from the Yiluo River, a tributary of the Yellow River, China's second longest river. Based on these samples, length–weight relationships (LWRs) and length–length relationships (LLRs) were estimated for 26 species. Among these data, LWRs for 1 species, LLRs for 11 species, and maximum total lengths for six species were not previously recorded in FishBase. The a values of the LWRs varied between 0.0019 and 0.0116, and b values from 2.805 to 3.883. All regressions for LWRs and LLRs were highly significant (p < .001). These results will be useful for sustainable management and conservation of the fish resources in the Yiluo River and the Yellow River ecosystem.     

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 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.     

Length–weight and length–length relationships of three Ambassid fishes from the Ganges River (NW Bangladesh)

Length–weight relationships (LWRs) and length–length relationships (LLRs) are presented for the first time for three Ambassid fish species from the Ganges River, northwestern (NW) Bangladesh. Fish were sampled with traditional fishing gear including cast net (mesh size ranges from 1.0 to 2.0 cm), gill net (mesh size ranges from 1.5 to 2.5 cm), square lift net (mesh size ~ 1.0 cm) and conical and box trap, October 2014 to September 2015. Allometric coefficient (b) values were 3.00 for Chanda nama, 3.10 for Parambassis lala and 3.23 for Parambassis ranga, respectively. Additionally, the LLRs were highly significant with r² ≥ .958. The present observations would be an effective tool for their stock assessment in the Ganges River, NW Bangladesh and surrounding ecosystems.     

Length–weight relationship of selected elasmobranch species from north‐eastern Arabian Sea,India

Length–weight relationship (LWR) was estimated for 12 elasmobranch species; five shark species, four species of rays and three species of guitar fishes from north‐eastern Arabian Sea, India. Five major landing centres of Maharashtra were selected; Satpati (Lat. 19°43′15″N, Long. 72°42′00″E), Naigaon (Lat. 19°19′32″N, Long. 72°48′54″E), Versova (Lat. 19°08′33″N, Long. 72°48′11″E), New ferry Wharf (Lat. 18°57′29″N Long. 72°51′01″E) and Sassoon dock (Lat. 18°54′42″N, Long. 72°49′33″E). Samples were collected fortnightly during August 2016 to October 2017 from various gears; drift gill nets (Hung length 114–143 m and #100–270 mm) off Satpati coast at 35–50 m depth, dol nets (length 50–65 m and cod end # 30–69 mm) in Naigaon at 38–50 m depth and trawl (length 33–72 m and cod end # 17–32 mm) in Versova, New ferry Wharf and Sassoon dock operated at 20–50 m depth. Multiday fishing was carried out with 2–3 fishing trips in a month, each trip with duration of 7–13 days. Soaking time of gill net and dol net varied from 4 to 8 hr while each trawl haul lasted for 3–4 hr. Length–weight/Disc‐width‐weight relationship showed good fit with r² values varying from 0.818 to 0.999. In addition to information on LWR, new maximum size for three species of elasmobranchs is reported in this paper.     

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).