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 three small indigenous fishes from the Payra River,southern Bangladesh

Length‐weight relationships (LWRs) and length‐length relationships (LLRs) for three small indigenous fishes (Esomus danrica, Pachypterus atherinoides and Salmostoma bacaila) were reported from the Payra River, southern Bangladesh. Samples were collected using traditional fishing gear including cast net (mesh size ranges from 1.0 to 2.0 cm), seine net (mesh size ranges from 1.5 to 2.5 cm) and square lift net (mesh size ~ 1.0 cm) in August to September 2017. Allometric coefficient (b) values were 2.66 for E. danrica, 3.08 for P. atherinoides and 3.06 for S. bacaila. The LLRs were also highly significant with r² ≥ .956.     

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 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 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 and length–length relationships of three ecologically important fishes caught from a wetland,northeastern Bangladesh

Length–weight relationships (LWRs) and length–length relationships (LLRs) of three ecologically important fishes (Aplocheilus panchax, Danio rerio and Esomus danrica) were reported from a wetland, northeastern Bangladesh (23 58 N, 89 38 E). Samples were collected monthly using traditional fishing gear including fine meshed (2.0 mm) push net and fine meshed (3.0–4.0 mm) surrounding net during January to December 2014. For each individual, total length (TL), fork length (FL) and standard length (SL) was measured to 0.1 cm, while body weight (BW) was measured to 0.01 g accuracy. Allometric coefficient (b) values were 3.10 for A. panchax, 3.38 for D. rerio and 3.52 for E. danrica. In addition, the LLRs were also highly significant with r² ≥ 0.954.     

Length–weight and length–length relationships of three cyprinid fishes from the Bibi‐Sayyedan River,western Iran

This study describes the length–weight and length–length relationships for three cyprinid species from the Bibi‐Sayyedan River (western Isfahan provinces, Iran). The slope parameter (b) values in the length–weight relationship equations were determined as 3.0729 for Alburnus mossulensis Heckel, 1843; 2.8509 for Barbus lacerta Heckel, 1843; and 3.0864 for Chondrostoma regium (Heckel, 1843). This study presents the first LWR and LLR references for these species in the Bibi‐Sayyedan River.     

Length–weight and length–length relationships of four native fish species from the Yalong River,China

Length‐weight and length‐length relationships were estimated for four native fish species from the Yalong River and its tributaries, China. A total of 976 specimens were collected monthly using trap nets and electric fishing in May 2013 and July 2015 to February 2016. This study presents the first references on LWRs (length–weight relationships) and LLRs (length–length relationships) for three species (Gymnocypris firmispinatus, Paracobitis variegatus and Euchiloglanis kishinouyei). Moreover, maturation length, absolute fecundity and predominant food items for the four species were also described in the study.     

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 and length‐length relationships of four Alosa species along the southern Caspian Sea coast

This study investigates length‐weight and length‐length relationships of four shad species (Alosa braschnikowi, Alosa caspia, Alosa kessleri, and Alosa saposchnikowii) captured on the southern Caspian Sea coast of Iran. The relationship of total length (TL), fork length (FL) and standard length (SL) and the relationship between total length and body weight are presented.     

Length‐length and length‐weight relationships for four fish species from Naolihe National Nature Reserve,Heilongjiang, China

In this study the length‐length and length‐weight relationships for four fish species from Naolihe National Nature Reserve in China belonging to three families and four genera were analyzed. They are Perccottus glenii Dybowski, 1877; Rhodeus sericeus Pallas, 1776; Cobitis lutheri Rendahl, 1935; and Misgurnus mohoity Dybowski, 1869. Fish samples were collected in May 2017 from Naolihe National Nature Reserve by fish catching cage (31*41 cm caliber, 16 m length, 3–5 mm mesh diameter), and identified as to species in the laboratory according to S. Q. Zhu (Synopsis of freshwater fishes of China, Jiangsu Science and Technology Publishing House, Nanjing, China, 1995).     

Length–weight and length–length relationships for some Yangtze River fishes in Tian‐e‐zhou Oxbow,China

Length–weight and length–length relationships are reported for 32 fish species belonging to seven families and 26 genera from the Tian‐e‐zhou Oxbow in the middle reach of Yangtze River, near Shishou City, China. The weight (W) ‐ length (L) relationships were estimated using the logarithmic form of the equation W = aL^b. The exponent b varied from 2.60 to 3.65 (mean ± SE: 3.12 ± 0.25). The 14 weight–length relationships, 13 length–length relationships, and seven maximum lengths are presented to FishBase for the first time.     

Length–weight and length–length relationships for six commercial fishes from southern Korean waters

Presented are the relationships between total length and weight, and between total length and standard length for six commercial fishes collected twice a month from local fish markets in southern Korea between 2005–2006 for Acanthopagrus schlegelii (Bleeker, 1854), Hexagrammos agrammus (Temminck & Schlegel, 1843) and Hexagrammos otakii (Jordan & Starks, 1895), and monthly in 2004 for Dentex tumifrons (Temminck & Schlegel, 1843), Doederleinia berycoides (Hilgendorf, 1879) and Scomberomorus niphonius (Cuvier, 1832). The LWR for D. tumifrons is estimated for the first time, and a new maximum length was recorded for S. niphonius. All total length and weight relationships were significant (all r² > .953). The values of exponent b, estimated using simple linear least squares of log‐transformed weight and length data, ranged from 2.945 to 3.317.     

Length–weight and length–length relationships for four fish species from Talkhehrud River,Urmia Lake basin,Iran

Length–weight and length–length parameters were calculated in the Talkhehrud River, northwestern Iran, for four freshwater fish species belonging to two families. The b values varied between 2.27 and 3.19, with a mean ± SD of 2.2777 ± 0.387. The b parameter values in the length–weight relationship equations were determined as 2.73 for Alburnus atropatenae Berg, 1925; 3.19 for Alburnoides petrubanarescui Bogutskaya & Coad, 2009; 2.92 for Capoeta capoeta (Güldenstädt, 1773); and 2.27 for Oxynoemacheilus persa (Heckel, 1847). This study provides the first reference on the LWRs and LLRs for these species in the Talkhehrud River.     

Length‐weight relationships of three fishes from the Nujiang River,China

The length‐weight relationships (LWR) for three fish species collected from the Nujiang River, China, were determined. Fishes were caught quarterly by drift gill net (stretched mesh size: 4 cm, depth: 2–4 m) and cast net (mesh size 1 cm; depth: 1–2 m) from May 2016 to July 2017. The values of parameter b in the LWR equations were estimated as 2.69 for Balitora nujiangensis Zhang & Zheng, 1983, 2.80 for Glyptothorax deqinensis Mo & Chu, 1986 and 2.94 for Pseudexostoma brachysoma Chu, 1979, respectively.     

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 six fishes from the Anning River,China

This paper provides the length–weight relationships for six fish species collected from the Anning River, one of the biggest tributaries of the Yalong River in China. A total of 1096 specimens belonging to six fish species were analyzed. Among them, the length–weight relationships for 4 fish species are first‐time reports for FishBase and new maximum lengths of one fish species is also reported.     

Length–weight and length–length relationships of five Mystus species from the Ganges and Rupsha rivers,Bangladesh

This study focused on the length–weight and length–length relationships of five Mystus species from Bangladesh. A sum of 398 individuals (Mystus bleekeri = 47, Mystus cavasius = 171, Mystus gulio = 59, Mystus tengra = 65, and Mystus vittatus = 56) was collected from the Ganges and Rupsha rivers, Bangladesh. Fishes were caught by gill net (mesh sizes: 2.0–4.0 cm) and cast net (mesh sizes: 1.5–3.0 cm) from July 2014 to June 2015. Total length (TL), fork length (FL) and standard length (SL) were measured to 0.1 cm, while whole body weight (W) was taken to the nearest 0.1 g for each individual. The TL ranged from 6.0–13.5 cm for M. bleekeri, 5.0–15.0 cm for M. cavasius, 7.4–17.2 cm for M. gulio, 4.6–11.6 cm for M. tengra and 5.5–12.3 cm for M. vittatus. The W varied from 3.0–18.2 g for M. bleekeri, 1.3–30.4 g for M. cavasius, 6.1–62.2 g for M. gulio, 1.7–15.1 g for M. tengra and 2.7–19.2 g for M. vittatus. All LWRs were highly significant (p < .001), with all r² values ≥.950. The LLRs were also highly significant (p < .001), with all r² ≥.980. This study provides information on LWRs and LLRs for M. gulio and M. tengra for the first time. The results of this study can be very effective for stock assessment of Mystus species in the Ganges and Rupsha rivers as well as in the surrounding ecosystems.     

Length‐weight and length‐length relationships of two gobiid fishes Eleotris fusca (Forster, 1801) and Odontamblyopus rubicundus (Hamilton, 1822) from the Payra River,southern Bangladesh

The present study provides the estimates of length‐weight relationships (LWRs) and length‐length relationships (LLRs) of two gobiid fishes Eleotris fusca and Odontamblyopus rubicundus from the Payra River, southern Bangladesh. Fish samples were collected from the set bagnet (mesh size <2 mm) fishers of the Payra River in July 2016. Allometric coefficient (b) values were 2.95 for E. fusca and 2.76 for O. rubicundus. Additionally, the LLRs were highly significant with r² ≥ .955. While the estimate of the LWR for O. rubicundus includes a substantial larger sample size and thus provides a more reliable LWR than the one published so far, the LWR for E. fusca must be considered as tentative because the sample includes only juveniles for a fish that reaches a maximum standard length more than three times as much. Additional studies are needed to further improve our LWR knowledge base for these fish species.     

Length‐weight relationships for small Midwestern US fishes

Herein, we provide length‐weight relationships for juvenile and smallbodied freshwater fishes of 20 species. Length‐weight parameters were estimated using data collected through four years of electrofishing surveys conducted in the rivers of Illinois, USA.