Technical contribution Length–weight relationships of four Cyprinid species in India By S. P. Das 1 , S. Swain 1 , D. Bej 1 , P. Jayasankar 1 , J. K. Jena 2 and P. Das 1 1 Central Institute of Freshwater Aquaculture, Bhubaneswar, Odisha, India; 2 National Bureau of Fish Genetic Resources, Lucknow, Uttar Pradesh, India Summary Length–weight relationships are reported for four Indian carps. The length–weight relationship was W = 0.01123L 3.355 for Cirrhinus mrigala, W = 0.07354L 3.299 for Catla catla, W = 0.04066L 3.313 for Labeo rohita and W = 0.11489L 2.732 for Labeo fimbriatus. LWR estimates for C. mrigala and L. fimbriatus had not been previously reported in FishBase. Introduction Length–weight relationships (LWR) of fishes are an impor- tant aspect of fishery biology and have a number of applica- tions in fish stock assessment (Chu et al., 2012). In the present investigation, LWR of four fish species from peninsu- lar regions of India were studied. Materials and methods Fishes were caught by gill net or cast net during 2009 to 2012 and identified as per Talwar and Jhingaran (1991). Specimen were collected and pooled from the peninsular rivers of Maha- nadi, Cuttack (20.27°N85.52°E); Godavari, Rajahmundry (16.59°N81.47°E); Krishna, Vijayawada (16.31°N80.37°E); Kaveri, Mysore (12.18°N76.38°E); Narmada, Varuch (21.7°N72.97°E); and Mahi, Anand (22.57°N72.93°E). Total length and weight (nearest 0.1 cm and 0.01 g, respectively) were recorded. The LWR was estimated by linear regression of log W = log a + b log L, where ‘W’ is the body weight (gm), ‘L’ is total length (cm), ‘a’ is the intercept and ‘b’ is the slope (Ricker, 1973). Prior to regression analysis of log W on log L, log-log plots were used to detect and exclude outliers (Froese, 2006). All statistical analyses including regression and calculation of correlation were done with MICROSOFT OFFICE EXCEL 2007 and PAST software (PAlentologial STatis- tics, Hammer et al., 2001). Results Four fish species from the peninsular rivers of India were studied in the present investigation. Results are provided in Table 1. Discussion The present study is the first report on LWRs for Indian carps from peninsular rivers. According to Froese (1998), the exponent b in LWR should be within the range of 2.5–3.5. The confidence limits observed in this study were well within this range and overlapped with the Bayesian confidence lim- its in FishBase. The results of the present investigation will be useful for conservation and management of the investi- gated species. Acknowledgements The authors are thankful to Indian Council of Agricultural Research, New Delhi for financial support under outreach activity, and the Director, ICAR-CIFA for laboratory facili- ties. Table 1 Descriptive statistics and estimated LWR parameters in four fish species from peninsular rivers, India Species n Total length range (cm) Total weight range (gm) a b 95% CL of b 95% CL of a r 2 Catla catla 157 18.0–73.3 075–6500 0.07354 3.299 3.253–3.386 À2.531 to (À2.309) 0.987 Cirrhinus mrigala 1 265 17.0–87.0 020–8500 0.01123 3.355 3.308–3.507 À2.883 to (À2.551) 0.970 Labeo fimbriatus 1 106 12.0–60.0 125–2875 0.11489 2.732 2.486–3.369 À2.554 to (À1.148) 0.853 Labeo rohita 209 15.5–77.0 030–5500 0.04066 3.313 3.278–3.408 À2.641 to (À2.419) 0.983 1, No references on Length–weight relationships in Fish Base. n, number of samples; a, b, regression coefficients; r 2 , correlation coefficient; 95% CL of b, Confidence Limits (95%) of b, 95% CL of a, Con- fidence Limits (95%) of a. J. Appl. Ichthyol. (2015), 1–2 © 2015 Blackwell Verlag GmbH ISSN 0175–8659 Received: April 29, 2014 Accepted: December 10, 2014 doi: 10.1111/jai.12762 Applied Ichthyology Journal of