Length–weight relationships of two schizothoracinae fish species from the Maquan River,the upper reaches of the Yarlung Zangbo River,Tibet, China

Length‐weight relationships (LWRs) were determined for two endemic fish species from the Maquan River, the upper of the Yarlung Zangbo River: (Ptychobarbus dipogon Regan, 1905, Schizothorax waltoni Regan, 1905). All the specimens were collected between May and September of 2014. Length–weight relationships for these two fish species were determined for the first time, and new maximum body weights were recorded for these two species. These results will be useful for fishery research, management and conservation of the Yarlung Zangbo River.     

Length–weight relationships of three small fish species caught in the Yarlung Zangbo River basin,China

Length–weight relationships (LWRs) were determined for three small fish species, Glaridoglanis andersonii (Day, 1870), Glyptosternum maculatum (Regan, 1905) and Pseudecheneis sulcatus (Mc‐Clelland, 1842) from the Yarlung Zangbo River basin, China. A total of 285 specimens were collected from the Yarlung Zangbo River in May and October 2017(frequency of sampling during the study period: once per month).The specimens were caught with fishing gear including drifting gillnets (nets: 10 × 1.0 m; mesh size: 3.0 cm) and shrimp cages (nets: 4.0 × 0.5 × 0.4 m; mesh size: 0.5 cm).     

Length–weight and length–length relationships of three fish species from the Yarlung Zangbo River in Tibet,China

Length–weight relationships and length–length were evaluated for three fish species (Schizopygopsis younghusbandi Regan, 1905; Ptychobarbus dipogon Regan, 1905 and Oxygymnocypris stewartii Lloyd, 1908) from the Yarlung Zangbo River in Tibet. Specimens were captured monthly using floating gillnets (mesh size 7.5 cm), bottom gillnets (mesh size 6.5 cm), and trap nets (mesh size 1.5 mm) from August 2008 to August 2009, March to August 2012, and March to April 2013. Regression coefficient (b) values of length–weight relationships (LWRs) ranged from 3.045 for P. dipogon to 3.193 for O. stewartii, whereas the a values ranged from 0.0040 to 0.0168 for O. stewartii and P. dipogon, respectively.     

Length–weight relationships of four fish species from the MoTuo reach of the Yarlung Zangbo River,southwest China

Length–weight relationships (LWRs) were evaluated for four fish species from the MoTuo reach of the Yarlung Zangbo River, southwest China: Exostoma labiatum (McClelland, 1842), Schizothorax curvilabiatus (Wu & Tsao, 1992), Nemacheilus subfusca (McClelland, 1839), and Garra kempi Hora, 1921. The a values ranged from 0.0094 (Schizothorax curvilabiatus) to 0.0151 (Exostoma labiatum), b values from 2.698 (Exostoma labiatum) to 2.974 (Schizothorax curvilabiatus), and r² values from 0.976 (Nemacheilus subfusca) to 0.995 (Schizothorax curvilabiatus). A total of 427 fish specimens were collected by electrofishing in April 2015, with LWRs previously unknown to FishBase for four of the species. New maximum lengths are recorded in FishBase for three of these species: Schizothorax curvilabiatus, Nemacheilus subfusca, and Garra kempi.     

Length–weight relationships of fish from Madeira River,Brazilian Amazon,before the construction of hydropower plants

Length–weight relationships (LWRs) are presented for 112 freshwater fish species representing 23 families and five orders captured in the Madeira River, the largest white‐water river tributary of the Amazon River. The allometry coefficient (b) of the LWR (Wt = aSL^b) ranged from 2.446 to 3.856 with a median value of 3.102. Eight new LWR records are presented for Amazonian species as information for FishBase. LWRs in the present study provide historical data on a and b coefficients prior to the damming of the Madeira River in November 2011, allowing comparison estimates of predicted future population parameters as influenced by human intervention.     

Length–weight and length–length relationships of three endemic fish species from the Yarlung Tsangpo River,China

The length‐weight (LWR) and length‐length relationships (LLR) were estimated for three endemic fish species, including Schizothorax waltoni Regan, 1905, Schizothorax oconnori Lloyd, 1908, and Schizothorax macropogon Regan, 1905 in the Yarlung Tsangpo River. A total of 399 specimens were collected using gillnets and cast nets during February to August 2012 and March to May 2013. No information regarding length–weight and length–length relationships was reported previously in FishBase for these three endemic species.     

西藏两种裂腹鱼鱼肉质构特征比较分析

巨须裂腹鱼Schizothorax macropogon和双须叶须鱼Ptychobarbus dipogon是雅鲁藏布江特有的重要经济鱼类, 具有多种人体必需脂肪酸, 营养价值高, 但其组织结构和内部性状可直接影响口感。为明确西藏2种裂腹鱼鱼肉的质构特征差异, 保护西藏裂腹鱼资源及其合理开发利用, 采用质地多面剖析法(TPA)分析了西藏雅鲁藏布江日喀则江段和林芝江段的2种裂腹鱼(巨须裂腹鱼、双须叶须鱼)的12项鱼肉质构特征指标, 主成分分析(PCA)表明雅鲁藏布江林芝江段双须叶须鱼鱼肉质构特征较日喀则江段2种裂腹鱼及林芝江段巨须裂腹鱼存在较大差异。析因分析表明可将雅鲁藏布江2种裂腹鱼鱼肉质构特征归纳为硬度、克服鱼肉表面与接触物吸引力及收缩性等3大类4个主成分指标, 前4个主成分累计方差贡献率达81.472%, 可将这3大类4个主成分指标作为雅鲁藏布江裂腹鱼鱼肉质构特征的主要判定参数。研究为后续合理开发利用雅鲁藏布江不同江段的裂腹鱼类提供科学数据。     

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 relationships of five endemic fish species from the lower Yarlung Zangbo River,Tibet, China

The length–weight relationships were estimated for five endemic fishes (Schizothorax curvilabiatus, Schizothorax molesworthi, Garra kempi, Neolissochilus hexagonolepis, Exostoma labiatum) from the Yarlung Zangbo River in Tibet, China. Fishing gear used for sampling included 4 cm mesh gill nets (100 m long × 1.2 m high) and electrofishing, from December 2015 to January 2016. Three of the species have new records of maximum length in FishBase.     

Length-weight and length-length relationships of three fish species from the lower Yalong River,China

Length-weight relationships (LWRs) and length-length relationships (LLRs) were evaluated for three endemic fish species sampled from the lower Yalong River and its biggest tributary (the Anning River), in China. Specimens were captured using set gillnet (mesh size 4 cm) and backpack electro-fishing (power output 400 W, depth fished 1 m, area covered 3 m²) from June to July 2018. LWRs and LLRs are presented for the following species (Sinogastromyzon sichangensis, Micropercops swinhonis and Percocypris pingi).     

Length–weight relationships of 14 Indian freshwater fish species from the Betwa (Yamuna River tributary) and Gomti (Ganga River tributary) rivers

The length‐weight relationships (LWRs) were studied of 588 fish covering eight families, 13 genera and 14 species (Notopterus notopterus, Gudusia chapra, Labeo calbasu, Puntius sarana, Cirrhinus mrigala, Ompok bimaculatus, Mystus tengara, Mystus cavasius, Sperata aor, Sperata seenghala, Eutropiichthys vacha, Wallago attu, Rhinomugil corsula, and Mastacembelus armatus) captured in the Betwa River (tributary of the Yamuna River) and Gomti River (tributary of the Ganga River) from December 2007 to January 2009. The b values varied between 2.4 (M. armatus) and 3.52 (P. sarana), with the mean b = 2.96 at P < 0.001 for all species. The observations are significant for conservation and management because the Betwa River has been approved under India’s first interlinking plan with the Ken River, and no length‐weight data had thus far been reported for the Gomti River. The objective was to evaluate the LWRs of these two unstudied rivers for fisheries management.     

Length‐weight relationship of 11 fish species from a tributary of the Amazon River system in northern Brazil

The length–weight relationships (LWRs) of 11 freshwater fish for eight families (Leporinus friderici, Pterophyllum scalare, Geophagus camopiensis, Curimata incompta, Astyanax bimaculatus, Tetragonopterus chalceus, Moenkhausia lepidura, Metynnis lippincottianus, Plagioscion squamosissimus, Hemiodus unimaculatus and Colomesus asellus) captured in tributary of the Amazon River system (Brazil) were investigated. These results represent the first reference on the LWRs for all 11 species in the eastern Amazon.     

Reproductive cycle of Triplophysa stenura (Herzenstein, 1888) (Balitoridae: Nemacheilinae) from the Yarlung Tsangpo River in the Tibetan Plateau,China

The reproductive biology of Triplophysa stenura, an indigenous cyprinid species from the Qushui County in the middle of the Yarlung Tsangpo River in the Tibetan Plateau, China, was investigated by bimonthly sampling from May 2014 to April 2015 using electrofishing. The gonadosomatic index (GSI) of T. stenura differed significantly between males and females over the seasonal trend, indicating that spawning extends from March (shortly after the ice melts) to May, as observed for indigenous species in response to environmental conditions on the cold plateau. Average oocyte diameter was 0.66 ± 0.13 mm, whereby the oocyte diameter distribution exhibited a clear seasonal pattern as the temporal pattern of GSI. Absolute fecundity of T. stenura was 3999 eggs/individual, which increased significantly with the increase in fish size and gonad weight, demonstrating the relationship of an exponential equation between them.     

Length–weight and length–length relationships for nine fish species from Lhasa River Basin,Tibet, China

The present study reports length–weight relationships (LWR) and length–length relationships (LLR) for five native freshwater fish species (Schizopygopsis younghusbandi, Triplophysa orientalis, T. tibetana, T. stewartii and T. stenura) and four introduced freshwater fish species (Pseudorasbora parva, Carassius auratus, Micropercops cinctus and Oryzias latipes) captured in the Lhasa River Basin, Tibet, China. Five of the LWRs are presented for the first time.     

Length–weight relationships of four cavefish species from China

Length‐weight relationships (LWRs) were estimated for four cavefish species belonging to the genus Sinocyclocheilus (Cypriniformes: Cyprinidae) occurring in the Nanpanjiang River and Hongshuihe River, which constitute the upstream of the species, S. angularis, S. furcodorsalis, S. rhinocerous, and S. tileihornes, were collected from 2011 to 2017. The b values of LWRs of these four species ranged from 2.830 to 3.719 and the correlation coefficient values (R²) were high for all species. This is the first record of LWRs for cavefish species with the horn in FishBase database.     

Length–weight relationships and condition factors of two fish species from the southern Caspian Sea basin: Alburnoides samiii Mousavi‐Sabet,Vatandoust & Doadrio, 2015 and Ponticola iranicus Vasil′eva,Mousavi‐Sabet & Vasil′ev, 2015

The present study describes the length–weight relationships (LWRs) and condition factors (K) of Alburnoides samiii and Ponticola iranicus in the Sefidroud River from the southern Caspian Sea basin, September 2013 to August 2014. This study presents the first known reference in the FishBase database regarding the LWRs and condition factors for these two indigenous species.     

Length–weight relationships for freshwater fish species from the Pantanal of the Negro River,Brazil

The present study describes the length‐weight relationships (LWRs) of 28 species captured in Santa Virgínia Bay, in the Pantanal of the Negro River, Mato Grosso do Sul State, Brazil, over 3 years (1999 to 2001). The study provides the first references on LWRs for thirteen of these species.     

Length–weight relationship for freshwater fish species from Brazilian Cerrado

Presented are length–weight relationship (LWR) estimates for 15 native fish species captured between 2010 and 2011, in the Munim River, Brazilian Cerrado basin. Samples were collected using gillnets of four different mesh sizes (3.0, 4.0, 5.0 and 6.0 cm), hand nets and a covo‐fish trap. Additionally provided are the first LWRs for eight species, specially the recently described species Charax awa Guimarães, Brito, Ferreira & Ottoni, 2018.     

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 relationship of two Ambassid fish species,Parambassis dayi (Bleeker, 1874) and Parambassis thomassi (Day, 1870) from River Pamba,Southern Western Ghats,India

The present study provides the length‐weight relationships (LWRs) of two Ambassid fish species, Parambassis dayi (Bleeker, 1874) and Parambassis thomassi (Day, 1870) from River Pamba in Southern Western Ghats, India. Fishes were collected on a monthly basis between April 2014 to March 2015 using gill nets (1.0–3.0 cm), cast nets (1.0–2.0 cm) and seine nets (1.0 cm). The b values in the LWRs were estimated as 3.01 for P. dayi and 3.14 for P. thomassi. No previous information is available on LWRs for these two species in FishBase.