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 relationships of seven fish species from the Yuan River,China

Length–weight relationships were determined for seven fish species (Culter oxycephaloides Kreyenberg & Pappenheim, 1908; Pseudobagrus tenuis Günther, 1873; Saurogobio dumerili Bleeker, 1871; Distoechodon tumirostris Peters, 1881; Pseudolaubuca engraulis Nichols, 1925; Liobagrus marginatoides Wu, 1930; and Parabotia bimaculata Chen, 1980) inhabiting the Yuan River, central China. Fishes were collected using gillnets and electroshock fishing techniques quarterly from January 2008 to December 2010. This study is first report the length–weight relationships for this seven fish species.     

Length–weight relationships for 15 fish species from the Three Gorges Reservoir

The length–weight relationships (LWRs) for 15 fish species from the Three Gorges Reservoir (TGR) were described in this paper. Specimens were collected using gill nets (mesh size: 6, 8, 10, 12 cm), cage net (mesh size: 1 cm), benthic fyke net (mesh size: 1 cm), hook longlines (80 m long, 3 barbless hooks per meter line) and electrofishing (power: 1,500 w; distance of electrodes: 1–2 m; water depth: 0.2–1.0 m; water area: 1–2 m²; catch by dip net [mesh size: 0.4 cm]) at four sections of the TGR, monthly in June–August and October–November in 2017 and 2018. The first LWR reference for Zacco acutipinnis (Bleeker, 1871), Discogobio brachyphysallidos Huang, 1989, Squalidus nitens (Günther, 1873), Leptobotia pellegrini Fang, 1936, Sinibotia reevesae (Chang, 1944), Pseudobagrus tenuifurcatus (Nichols, 1931), Pseudobagrus medianalis (Regan, 1904), Liobagrus marginatoides (Wu, 1930), Glyptothorax fokiensis (Rendahl, 1925), and Ctenogobius szechuanensis (Liu, 1940) and new maximum total length for 12 species are provided.     

Length‐weight relationships of eleven fish species from the middle reaches of Jinsha River,southwest China

Length‐weight relationships (LWRs) were determined for eleven endemic fish species [Coreius guichenoti (Sauvage & Dabry de Thiersant, 1874), Glyptothorax sinensis (Regan, 1908), Leptobotia elongata (Bleeker, 1870), Leptobotia taeniops (Sauvage, 1878), Pseudobagrus crassilabris (Günther, 1864), Rhinogobio ventralis (Sauvage & Dabry de Thiersant, 1874), Saurogobio dabryi (Bleeker, 1871), Schizothorax chongi (Fang, 1936), Schizothorax kozlovi (Nikolskii, 1903), Schizothorax prenanti (Tchang, 1930) and Schizothorax wangchiachii (Fang, 1936)] from the middle reaches of the Jinsha River in southwest China. Samples were obtained between May 2004 and July 2013 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. Prior to this study, the LWRs for four species (P. crassilabris, S. chongi, S. kozlovi and S. prenanti) were unknown.     

Length‐weight relationships of nine fish species from the upper reach of the Gan River,a tributary of the Yangtze River in China

Length‐weight relationships (LWRs) are reported for nine fish species belonging to four families from the upper reach of the Gan River, one of the main tributaries of the Yangtze River, China. A total of 807 specimens were collected from April 2016 to July 2017. Fishes were both sampled using a backpack electrofishing unit and collected from local fish markets that using various fishing gears such as electrofishing boats, gillnets (mesh sizes: 1–12 cm), hooks, and benthic fyke nets (mesh sizes: 0.5 cm and 0.7 cm). The fish species were Siniperca undulata (Fang & Chong, 1932), Pseudogobio vaillanti (Sauvage, 1878), Sarcocheilichthys parvus (Nichols, 1930), Barbodes semifasciolatus (Günther, 1868), Spinibarbus hollandi (Oshima, 1919), Gobiobotia meridionalis (Chen & Cao, 1977), Pseudobagrus albomarginatus (Rendahl, 1928), Pseudogastromyzon changtingensis (Liang, 1942), and Pseudogastromyzon fangi (Nichols, 1931). The a values for the nine species varied between 0.0056 and 0.0366, the b values ranged from 2.333 to 3.318, and r² values from .952 to .994.     

Length–weight and length–length relationships of four endemic fish species from the middle reaches of the Yangtze River basin,China

Length–weight (LWR) and length–length relationships (LLR) were evaluated for four endemic fish species, including Hemibagrus macropterus Bleeker, 1870; Rhinogobio cylindricus Günther, 1888; Rhinogobio typus Bleeker, 1871; and Siniperca scherzeri Steindachner, 1892, in the middle reaches of the Yangtze River basin. A total of 252 specimens were collected using gillnets and cast nets between November 2014 and January 2016. No information regarding length–weight and length–length relationships were reported previously in FishBase for these four endemic species.     

Length–weight relationships of three fish species from the Yangtze River,China

Length–weight relationships (LWRs) were determined for three endemic fish species [Gobiobotia filifer (Garman, 1912), Homatula potanini (Günther, 1896) and Xenophysogobio boulengeri (Tchang, 1929)] from the Yangtze River in China. Samples were obtained between April 2008 and June 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. Prior to this study, the LWRs for two species [Gobiobotia filifer (Garman, 1912) and Homatula potanini (Günther, 1896)] were unknown.     

Length–weight relationships of 11 fish species from the Nuoshuihe Precious Water Animal National Nature Reserve,southwestern China

Length–weight relationships (LWRs) are presented for 11 species [Acrossocheilus monticola (Günther, 1888), Squalidus wolterstorffi (Regan, 1908), Sinibrama taeniatus (Nichols, 1941), Gnathopogon herzensteini (Günther, 1896), Rhynchocypris oxycephalus (Sauvage & Dabry de Thiersant, 1874), Rhodeus lighti (Wu, 1931), Platysmacheilus nudiventris Luo, Le & Chen, 1977, Hemibagrus macropterus Bleeker, 1870, Glyptothorax fokiensis (Rendahl, 1925), Liobagrus marginatoides (Wu, 1930), Sinogastromyzon szechuanensis Fang, 1930] from the Nuoshuihe Precious Water Animal National Nature Reserve in southwestern China. Samples were collected bimonthly with trap‐nets (mesh size: 5 × 5 mm; height 0.3 m; width 0.4 m; length 7 m) from 2015 to 2016.     

Length–weight relationships for three freshwater fish species from the Pengxi River (a tributary of the Yangtze River,China)

This study determined the length–weight relationships of three freshwater fish species [Culter oxycephaloides (Kreyenberg & Pappenheim, 1908), Squalidus argentatus (Sauvage & Dabry de Thiersant, 1874), Rhodeus sinensis (Günther, 1868)] from Pengxi River, a tributariy of Yangtze River of China. Fish were collected during 2016 using drift gill nets (mesh size 1, 2 and 3 cm) and cage net (0.5 cm mesh size). For Culter oxycephaloides had no previous length–weight estimates were reported in the science literature. For Squalidus argentatus the present estimate includes a new maximum total length while for Rhodeus sinensis our study confirms the only existing LWR estimate quite well.     

Length-weight relationships of eight reservoir fish species in Puerto Rico

Length-weight relationships (LWR) of eight fish species, Lepomis auritus (Linnaeus, 1758), Amphilophus labiatus (Günther, 1864), Oreochromis mossambicus (Peters, 1852), Cichla ocellaris Bloch & Schneider, 1801, Parachromis managuensis (Günther, 1867), Vieja melanura (Günther, 1862), Pterygoplichthys pardalis (Castelnau, 1855), and Gobiomorus dormitor Lacepède, 1800, collected by electrofishing and gillnetting from ten reservoirs in Puerto Rico were determined using 3,557 individual fish records collected between 1998 and 2014. All LWRs were significant with r² values ranged from 0.900 for A. labiatus (Günther, 1864) to 0.996 for C. ocellaris Bloch & Schneider, 1801. The LWR parameter b ranged from 2.807 for P. pardalis (Castelnau, 1855) to 3.180 for C. ocellaris Bloch & Schneider, 1801. Data presented herein expand the knowledge base for these species as they have limited or no LWR data available. Also, our samples provide a new maximum length data for P. pardalis (Castelnau, 1855).     

Length–weight relationship of five fish species from the Xiaonanhai reach of the Upper Yangtze River,southwest China

Length–weight relationships (LWRs) were determined for five fish species, including two endemic species [Platysmacheilus nudiventris (Luo, Le & Chen, 1977), and Rhinogobio cylindricus (Günther, 1888)] from the Xiaonanhai reach of the Upper Yangtze River in southwest China. Samples were obtained between July 2011 and October 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. Length–weight relationships for two species were unknown to FishBase, and new maximum lengths are recorded for two species.     

Length–weight relationship of three fish species from the Qiantang River,China

Length–weight relationships (LWRs) of the three fish species, Pseudobagrus albomarginatus(Rendahl, 1928), Pseudobagrus crassilabris (Günther, 1864), and Rhinogobius davidi(Sauvage & Dabry de Thiersant, 1874), were determined respectively. Samples were collected from Qiantang River, China during March 2016–December 2017. The bvalues ranged from 2.525 to 2.917, the coefficient of determination (r²) ranged from 0.96 to 0.97. Prior to this study, the length–weight relationship for P. albomarginatus and R. davidi were unknown to FishBase and the new maximum total lengths for three species were not recorded in FishBase. These results are useful for the fishery research and management in Qiantang River.     

Length–weight relationships of two fish species from the Yangtze River,China

Fish samples for the study were collected from the Yangtze River in China. Length–weight relationships were determined for two endemic fish species (Leiocassis longirostris Günther, 1864 and Schistura fasciolata Nichols & Pope, 1927) for the first time.     

Length–weight relationships of four fish species from the Niulan River,China

This study provides the length–weight relationships (LWRs) for four fish species [Leptobotia rubrilabris (Dabry de Thiersant, 1872); Opsariichthys bidens Günther, 1873; Xenocypris yunnanensis Nichols, 1925; and Sinogastromyzon sichangensis Chang, 1944] collected from the Niulan River, China. Samples were obtained between April 2008 and June 2011 using various types of fishing gear [drift gill nets (mesh: 5 × 5 cm), hook and electro fishing]. A total of 136 specimens belonging to four fish species were analyzed. For each species the sample size, length range, weight range, LWR, 95% confidence intervals of a and b, and coefficient of correlation were determined. Prior to this study, the LWRs for S. sichangensis and X. yunnanensis were unknown. New maximum sizes for S. sichangensis and X. yunnanensis are also provided.     

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 for three fish species from the coastal waters of the northern Yellow Sea,China

Length–weight relationships (LWRs) were determined for three fish species: Thamnaconus modestus(Günther, 1877), Callionymus beniteguri  ( Jordan & Snyder, 1900) and Takifugu rubripes (Temminck & Schlegel, 1850), collected from the coastal waters of the northern Yellow Sea (near Dalian City) using bottom trawl nets in October 2017 and set nets in April 2018. Parameter b values in the fitted LWRs were 3.367(T. modestus), 2.817(C. beniteguri) and 3.200 (T. rubripes), respectively.     

Length–weight relationships for four small fish species caught in wetlands of central Yangtze River,China

Length–weight relationships for four native species (Oryzias latipes Temminck & Schlegel, 1846; Rhodeus ocellatus Kner, 1866; Rhinogobius giurinus Rutter, 1897; and Micropercops swinhonis Günther, 1873) were determined. The fish were collected from the wetlands of the central Yangtze River, in Wuhan, Hubei Province, China. Samples were obtained from May 2012 to January 2013. Length–weight relationships for O. latipes were determined for the first time.     

Length–weight relationships of three fish species from the Jinsha River,southwestern China

Length–weight relationships were determined for the first time for three fish species (Xenocypris fangi Tchang, 1930; Microphysogobio kiatingensis Wu, 1930; and Opsariichthys bidens Günther, 1873) from the Jinsha River, southwestern China. Samples were collected using gillnets (30 × 15 m, mesh‐size 5 mm) and electroshock fishing techniques (CWB‐2000 P, 12 V, 250 Hz ).     

Length–weight relationships for two loach species,Sinibotia superciliaris (Günther, 1892) and Sinibotia reevesae (Chang, 1944) collected from the Tuojiang River,China

Length–weight relationships were determined for two loach species, Sinibotia superciliaris (Günther, 1892) and Sinibotia reevesae (Chang, 1944). Samples were collected with gill nets (30 × 15 m, mesh‐size 1.5 cm) and fish cages (mesh‐size 0.5 cm) as well as by electroshock (CWB‐2000 P, 12 V, 250 HZ) between May 2013 and June 2015 from the Tuojiang River in southwest China. It is believed that the size range covered is close to a commonly known size range of each species. The length–weight relationship values of b were determined as 3.105 for S. superciliaris and 3.381 for S. reevesae. The data will be helpful in further research regarding these species in the upper Yangtze River Basin.     

Length–weight relationships for five endemic fish species in the upper Yangtze River basin,China

Length – weight relationships were estimated for five endemic fish species in the upper Yangtze River: Platysmacheilus nudiventris Luo, Le & Chen, 1977, Xenophysogobio nudicorpa (Huang & Zhang, 1986), Homatula potanini (Günther, 1896), Leptobotia rubrilabris (Dabry de Thiersant, 1872), and Euchiloglanis kishinouyei Kimura, 1934. The a values ranged from 0.0079 to 0.0134, and b values from 2.833 to 3.081. These five endemic species are rare, small and difficult to find and capture. Thus the sampling period was lengthy, from May 2010 to May 2014. A total of 718 specimens were available for analysis, and the length – weight relationships are the first reports for these five endemic fish species.