Int. J. Aquat. Biol. (2018) 6(5): 294-295 ISSN: 2322-5270; P-ISSN: 2383-0956 Journal homepage: www.ij-aquaticbiology.com © 2018 Iranian Society of Ichthyology Short Communication Length-weight relationship for four fish species from the Oman Sea, Iran Asghar Jafari-Patcan, Soheil Eagderi*,1Atta Mouludi-Saleh Department of Fisheries, Faculty of Natural Resources, University of Tehran, Karaj, Iran. Article history: Received 28 September 2018 Accepted 22 October 2018 Available online 2 5 October 2018 Keywords: Oman Sea, LWR, Trawling, Parameter b. Abstract: The present study reports length-weight relationship (LWR) of four fish species viz. Pennahia macrophtalmus, Epinephelus bleekeri, Acropoma joponicum and Trichiurus lepturus from the Oman Sea, Iran. A total of 880 specimens were collected from December 2016 to August 2017 by trawling. The LWR parameter b for the studied species was 2.68 to 3.07. Introduction The length-weight relationship of fishes is used to estimate the weight of a specimen from its length and vice versa, evaluation of fish stocks, estimating biomass, ontogenetic changes, growth rate studies and understanding the life cycle (Froese, 2006; Sarkar et al., 2008; Kumolu-Johnson and Ndimele 2010). Such information is scarce for fish species of the Oman Sea, hence feels its necessity for fisheries management (Oscoz et al., 2005). This contribution presents the parameters of LWRs for four species viz. Pennahia macrophtalmus, (Acanthuriformes: Sciaenidae), Epinephelus bleekeri (Perciformes: Serranidae), Acropoma joponicum (Perciformes: Acropomatidae) and Trichiurus lepturus (Scombriformes: Trichiuridae) from the Oman Sea. Materials and Methods The sampling was carried out on a monthly basis. A total of 880 specimens of four species, including 219 P. macrophtalmus, 81 E. bleekeri, 241 A. joponicum and 339 T. lepturus were collected in the depths of 168-276 m by trawling (30 mm mesh size) from the Oman Sea during December 2016 to August 2017. The collected fishes were preserved in the buffered 10% formalin at the field and transported to the *Corresponding author: Soheil Eagderi DOI: https://doi.org/10.22034/ijab.v6i5.562 E-mail address: soheil.eagderi@ut.ac.ir Fisheries Laboratory of University of Tehran. The total length (TL) and total weigh of each individual were measured using dial calipers and digital scale to the nearest 0.1 mm and 0.1 g, respectively. The length-weight relationship was estimated by W=aLb, and the logarithmic length‐weight equation as follows: Log(w) = Log(a)+blog(L). Where W is the whole-body weight (g); L = the total length (mm), a = the intercept and b = the slope. Prior to regression analyses, log-log plots of the length-weight pairs were performed to identify outliers (Froese et al., 2011; Radkhah and Eagderi 2015). Outliers perceive in the log-log plots of all species were evacuated from the regression. All statistical analyses were performed in Excel 2016. Results The specimens were ranged from 64.1-870.2 mm in total length and 48.1-5400 g in total weight. The number of samples, minimum and maximum of total length (mm), minimum and maximum of weight (g), length-weight relationships parameters (a, 95%CI-a, b and 95%CI-b) and the coefficient of determination (r2) of four studied species, including macrophtalmus, E. bleekeri, A. joponicum and T. lepturus are presented in Table 1. LWR ranged 2.68 for A. joponicum to 3.07 for E. bleekeri. All 295 Int. J. Aquat. Biol. (2018) 6(6): 294-295 relationships were highly significant (P<0.05) with r2 values greater than 0.75 in four species (r2 = 0.75- 0.95). Discussion The values of the b in LWRs falls between 2.5 and 3.5 (Froese, 2006) or 2-4 (Tesch, 1971). The value of b for P. macrophtalmus (2.72), E. bleekeri (3.07), A. joponicum (2.68) and Trichiurus lepturus (2.71) are in the expected range (Tesch, 1971; Froese, 2006; Zamani-Faradonbe et al., 2015a, b). This study provided some basic information that will be useful for their fishery management and fish population dynamic studies. Acknowledgments We are pleased to thank University of Tehran for financial support. References Froese R. (2006). Cube law, condition factor and weight- length relationships: history, meta-analysis and recommendations. Journal of Applied Ichthyology, 22: 241-253. Froese R., Tsikliras A.C., Stergiou K.I. (2011). Editorial note on weight–length relations of fishes. Acta Ichthyologica Et Piscatoria, 41(4): 261-263. Kumolu-Johnson C.A., Ndimele P.E. (2010). Length- weight relationships and condition factors of twenty- one fish species in Ologe Lagoon, Lagos, Nigeria. Asian Journal of Agricultural Science, 2: 174-179. Oscoz J., Campos F., Escala M.C. (2005). Weight–length relationships of some fish species of the Iberian Peninsula. Journal of Applied Ichthyology, 21: 73-74. Radkhah A., Eagderi S. (2015). Length-weight and length- length relationships and condition factor of six cyprinid fish species of Zarrineh River (Urmia Lake basin, Iran). Iranian Journal of Ichthyology, 2(1): 61-64. Sarkar U.K., Negi R.S., Deepak P.K., Lakra W.S., Paul S.K. (2008). Biological parameters of the endangered fish Chitala chitala (Osteoglossiformes: Notopteridae) from some Indian rivers. Fisheries Research, 90(1-3): 170-177. Tesch F.W. (1971). Age and growth. In: W.E. Ricker (Ed.). Methods for assessment of fish production in fresh waters. Blackwell Scientific Publications, Oxford. pp. 98-130. Zamani Faradonbeh M., Eagderi S., Ghojoghi F. (2015a). Length-weight relationship and condition factor of seven fish species of Totkabon River (southern Caspian Sea basin), Guilan, Iran. International Journal of Aquatic Biology, 3(3): 172-176. Zamani Faradonbe M., Eagderi S., Naserabad S.S. (2015b). Length-weight relationships and condition factor of three fish species from Taleghan River (Alborz Province, Iran). Journal of Advance Botany and Zoology, 2: 1-3. Table 1. Descriptive statistics and estimated parameters of length-weight relationships for four species from Oman Sea, Iran. species Total length (mm) Weight (g) Regression parameters n min max min max a b r2 95% CL of b 95% CL of a P. macrophtalmus (Bleeker,1549) 219 166.3 438.2 48.1 1004.1 0.0005 2.72 0.85 2.32-3.07 0.0001-0.0009 E. bleekeri (Vaillant,1878) 81 240.2 870.2 203.0 5400.3 0.0001 3.07 0.95 2.47-3.10 0.0001-0.0005 A. joponicum (Gunther,1859) 241 64.1 271.3 5.3 65.5 0.0008 2.68 0.88 2.57-3.13 0.0005-0.0009 T. lepturus (Linnaeus,1758) 339 191.6 545.6 100.0 1601.0 0.0006 2.71 0.75 2.64-3.24 0.0003-0.0009 n, number of individuals; a, intercept; b, slope; CI, confidence intervals; r2, coefficient of determination.