Length–weight relationships of four indigenous freshwater fish species from Khalsi wetland in lower Ganga basin,West Bengal,India

The length‐weight relationships of four indigenous freshwater fishes Parambassis lala (Hamilton, 1822), Trichogaster lalius (Hamilton, 1822), Puntius terio (Hamilton, 1822), and Pethia phutunio (Hamilton, 1822) were determined. Fish samples were collected during December 2013 to May 2015 from Khalsi, a floodplain wetland along the tributary of the River Ganges in West Bengal state, India using different types of gear (castnets, gillnets and drag nets, stretched mesh sizes of 15–20 mm, 20–30 mm and 5–10 mm, respectively). This is the first report on the length–weight relationship parameters of these four species.     

Length–weight and length–length relationships of some small indigenous fish species from the Mathabhanga River, southwestern Bangladesh

The present study describes the length–weight (LWR) and length–length (LLR) relationships for eight important small indigenous fish species (SIS) from the Mathabhanga River, southwestern Bangladesh, namely Amblypharyngodon mola (Hamilton, 1822), Channa punctata (Bloch, 1793), Hyporamphus quoi (Valenciennes, 1847), Macrognathus aculeatus (Bloch, 1786), M. pancalus (Hamilton, 1822), Nandus nandus (Hamilton, 1822), Puntius sophore (Hamilton, 1822), and Setipinna phasa (Hamilton, 1822). A total of 2543 specimens used for this study was caught by traditional fishing gear from January to December 2005. To the best knowledge of the authors, this study presented the first reference on LWR and LLR for these species from Bangladeshi waters.     

Length‐weight and length‐length relationships and form factor of three threatened fishes from the Ganges River (NW Bangladesh)

Data and information are needed to avert the alarming decline and initiate conservation measures for three threatened fishes, Labeo boga (Hamilton, 1822), Nandus nandus (Hamilton, 1822) and Puntius ticto (Hamilton, 1822), from the Ganges River and surrounding ecosystems. These fishes are decreasing rapidly due to high fishing pressures as well as environmental degradation. This study furnishes the length–weight relationships (LWRs), length–length relationships (LLRs) and form factor (a_3.0) of these three threatened species from the Ganges River, northwestern Bangladesh. A total of 773 specimens from the three species and two families used for this study were caught by traditional fishing gear between April 2011 and March 2012. The analysis of covariance (ancova ) revealed significant differences between the sexes in LWRs for L. boga (P < 0.001), but not with the remaining species (P > 0.05). Furthermore, the LLRs were highly correlated (r² > 0.983; P < 0.001), and ancova analyses additionally indicated that LLRs did not differ between sexes (P > 0.05). The calculated form factor (a_3.0) was 0.0111, 0.0159 and 0.0129 for L. boga, N. nandus and P. ticto, respectively. This study presents the first references on LWRs, LLRs and form factor for these three threatened species in Bangladesh. The results would be useful for further studies on the population assessment and sustainable conservation of the limited stocks in the Ganges River ecosystem.     

Length–weight relationships of Barilius bendelisis (Hamilton, 1807), Barilius shacra (Hamilton, 1822) and Barilius barna (Hamilton, 1822) from Manas River in Assam,India

The present study describes the length–weight relationships (LWRs) for three ornamental hill stream fish species from the Manas River in Assam, India, namely, Barilius bendelisis (Hamilton, 1807), Barilius shacra (Hamilton, 1822), and Barilius barna (Hamilton, 1822). Fishes were collected on a monthly basis from March 2015 to February 2016 with cast nets (270 cm, 1.2 cm) and gillnets (7,500 × 130 cm, 5 cm). This is the first information on LWR data for two of the species.     

Length–weight and length‐length relationships of four endemic fish species caught from Payra River,Southern Bangladesh

The present study estimated the length–weight relationship (LWR) and length‐length relationships (LLR) of four fish species, Ompok pabo (Hamilton, 1822), Acentrogobius cyanomos (Bleeker, 1849), Acentrogobius caninus (Valenciennes, 1837) and Gagata cenia (Hamilton, 1822) collected from the Payra river over a period of 1 year between July 2015–June 2016 using set bag nets and cast nets with a mesh size of 0.5 cm and <0.5 cm, respectively. Altogether 593 individuals of O. pabo (59), A. cyanomos (221), A. caninus (240) and G. cenia (73) were sampled and studied. LWRs of O. pabo, A. cyanomos, and A. caninus are presented for the first time in Fishbase.     

Length‐weight relationships of five fish species collected from Ranganadi River (Brahmaputra River tributary) in Assam,India

Length‐weight relationships (LWR) are presented for five fish species: Laubuka laubuca (Hamilton, 1822); Aspidoparia jaya (Hamilton, 1822); Channa gachua (Hamilton, 1822); Acanthocobitis botia (Hamilton, 1822) and Badis badis (Hamilton, 1822) collected from the Ranganadi River in the Lakhimpur district of Assam, India. There were no prior LWR data regarding three of these species.     

Reproductive biology of Pethia ticto (Cyprinidae) from the Gorai River (SW Bangladesh)

Some aspects of reproductive biology of Pethia ticto (Hamilton, 1822) from the Gorai River of southwestern (SW) Bangladesh were investigated by regular monthly samples for a period of one year during July 2010 to June 2011. A sum of 1200 specimens (male = 454 and female = 746) were collected using cast net, lift net and conical trap. Total length (TL) and Body weight (BW) were measured with slide caliper and digital balance, respectively for each individual. Based on gonadosomatic index (GSI), modified gonadosomatic index (MGSI) and Dobriyal index (DI) first sexual maturity was 4.30 cm TL for male and 4.80 cm TL for female. Also, on the basis of higher values of GSI, MGSI and DI spawning season was ranged from April to September for P. ticto in the Gorai River ecosystem. The fecundity was ranged from 2230–8450 with a mean value of 4779 ± 1578. In addition, there was a significant relationship between total length and fecundity (r² = .931, p < .001); body weight and fecundity (r² = .943, p < .001). Therefore, the findings of this study would be very effective for sustainable management of this threatened species in the Gorai River and surrounding ecosystem.     

Length‐weight relationships of Barilius barila (Hamilton, 1822), Opsarius tileo (Hamilton, 1822) and Cyprinion semiplotum (McClelland, 1839) collected from Manas River in Assam,India

Length‐weight relationships (LWRs) are presented for three hill stream fish species belonging to the family Cyprinidae namely, Barilius barila (Hamilton, 1822), Opsarius tileo (Hamilton, 1822) and Cyprinion semiplotum (McClelland, 1839). Fishes were collected on a monthly basis from January 2016 to December 2017 with the help of cast net (270 cm length, 1.2 cm mesh size) and gillnet (7,500 cm length × 130 cm depth, 5 cm mesh size) from the Manas river in Assam, India.. A new length record for the FishBase LWR database was observed in B. barila.      

Length–weight relationships of three fish species from the Bay of Bengal,Bangladesh

The present study describes the length–weight (LWR) of three fish species, Chela cachius (Hamilton, 1822), Coilia ramcarati (Hamilton, 1822) and Sardinella gibbosa (Bleeker, 1849) captured in the Bay of Bengal, Bangladesh, from December 2014 to November 2015. Fishes were captured with either gill nets (mesh size 2.0–5.0 cm) or set bag nets (mesh size 2.0–4.0 cm). The b values in the study varied from 2.88 (C. ramcarati) to 3.00 (S. gibbosa), with a mean a value of 2.94 at p < .001 for all three species. In addition, the study provides initial information on LWRs for C. cachius and C. ramcarati and maximum length records for C. cachius and S. gibbosa.     

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 relationships of two cyprinid fish species,Crossocheilus latius (Hamilton, 1822) and Garra gotyla gotyla (Gray, 1830) from the Ganga River Basin,India

This study provides length–weight relationship (LWR) information for two fish species (family Cyprinidae), Crossocheilus latius (Hamilton, 1822) and Garra gotyla gotyla (Gray, 1830), from a tributary of the Ganga River Basin, India. Both species had no previous LWR estimates as per Fishbase 2014.     

Length–weight and length–length relationship of Thryssa purava (Hamilton, 1822), Thryssa polybranchialis Wongratana, 1983 and Thryssa mystax (Bloch & Schneider, 1801) from Chilika lagoon,India

Current study provides basic information on Length–weight relationship (LWR) and length‐length relationship (LLR) of three fish species of genus Thryssa (Clupeiformes: Engraulidae) i.e., Thryssa purava (Hamilton, 1822), Thryssa polybranchialis Wongratana, 1983 and Thryssa mystax (Bloch & Schneider, 1801) from Chilika Lagoon, India. Samples were collected during the monsoon (July) and post‐monsoon (November) seasons in 2016 and during the pre‐monsoon season (May) in 2017, using screen barrier nets (mesh size 8–18 mm) and gill nets (mesh size 14 and 16 mm). The b values were determined from LWRs as 3.026 for Thryssa purava, 3.326 for Thryssa polybranchialis and 3.081 for Thryssa mystax.     

Length‐weight relationships (LWRs) of four freshwater fish species from the Brahmaputra and Barak river basins,northeast India

The present study describes the length‐weight relationships (LWRs) were determined for four fish species, collected from the Brahmaputra and Barak river basins in northeast India using cast nets (2.5 × 1 m; 10–15 mm mesh size) and gillnets (30 × 0.9 m; 5–10 mm mesh size), from June 2016 to July 2017. The b values in LWRs were determined as 2.70 for Badis tuivaiei Vishwanath & Shanta, 2004, 2.93 for Canthophrys gongota (Hamilton, 1822), 2.62 for Glyptothorax botius (Hamilton, 1822), and 3.22 for Gogangra viridescens (Hamilton, 1822).     

Length–weight relationships of four fish species from a coastal artisanal fishery,southern Bangladesh

This study presents the first report of length–weight relationships (LWRs) for Apocryptes bato (Hamilton, 1822), Salmophasia phulo (Hamilton, 1822), and Silonia silondia (Hamilton, 1822), excluding Anodontostoma chacunda (Hamilton, 1822), from fishermen's catches landed in a coastal artisanal fishery at Patuakhali, Southern Bangladesh. Specimens were sampled occasionally over a period of 1 year between August 2014 and September 2015. Fishes were collected from coastal fishermen using cast nets (mesh size <0.5 cm) for A. bato, set bag nets (mesh size 0.5 cm) for A. chacunda and S. silondia, and lift nets (mesh size <0.5 cm) for S. phulo. The LWRs obtained were W = 0.006L^2.99, (r²) = 0.976, W = 0.011L^3.04, (r²) = 0.971, W = 0.006L^3.00, (r²) = 0.945 and W = 0.007L^2.99, (r²) = 0.988 for A. bato, A. chacunda, S. phulo, and S. silondia, respectively.     

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 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 relationship of three Cynoglossus species (C. puncticeps,C. lingua and C. lida) from Chilika lagoon,India

The present study provides length–weight relationship (LWR) of three fish species, Cynoglossus puncticeps (Richardson, 1846), Cynoglossus lingua Hamilton, 1822 and Cynoglossus lida (Bleeker, 1851) of family Cynoglossidae from Chilika lagoon (19°28′–19°54′N; 85°05′–85°38′E), India. A total of 147 specimens were sampled during March, July and October of 2017 from screen barrier nets (mesh 14 mm to 26 mm) locally called khonda jal operated by local fishermen. The estimated b values derived from the data sets as follows: 3.12 for C. puncticeps, 3.09 for C. lida, and 2.88 for C. lingua.     

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 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 relationship of six indigenous fish species from Deepor beel,a Ramsar site in Assam,India

Length–weight relationships for six small indigenous fish species, namely: Trichogaster chuna (Hamilton, 1822), Trichogaster lalius (Hamilton, 1822), Trichogaster fasciata Bloch & Schneider, 1801, Chanda nama Hamilton, 1822, Parambassis lala (Hamilton, 1822), and Macrognathus aral (Bloch & Schneider, 1801) were studied for the first time from Deepor beel, a Ramsar site (589 ha water spread area) located in Assam, India. A total of 617 fish specimens were collected for the present study on a monthly basis from February to August in 2016 from landing centres adjoining the beel. In the present study, b value ranges from 2.778 to 3.215, which is within the normal range. The LWRs for these six fish species from Deepor beel had not yet been reported for FishBase.