Reproductive biology of Metaschistura cristata in northeastern Iran

Authors

  • O. Safari,

    Corresponding author
    1. Department of Fishery, Faculty of Natural Resources and Environment, Ferdowsi University of Mashhad, Mashhad, Iran
    • Author's address: Omid Safari, Department of Fishery, Faculty of Natural Resources and Environment, Ferdowsi University of Mashhad, P.O. Box 91775-1363 Mashhad, Iran.

      E-mail: omidsafari@um.ac.ir

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  • M. Naserizadeh

    1. Department of Fishery, Faculty of Natural Resources, University of Tehran, Tehran, Iran
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Summary

The study purpose was to investigate the reproductive biology, growth and length-weight of the Turkmenian crested loach, Metaschistura cristata, in the Radkan River of northeastern Iran. Age and growth are described for 1029 specimens from January 2009 to December 2010. The sex ratio was 1:1. Maximum age, based on opercula readings, was 6+ years for both sexes. Specimens ranged in size from 24 to 98 mm total length and weighed from 0.08 to 7.32 g. The length-weight relationships were described as W = 0.005166 TL3.225 (R2 = 0.97) for males and W = 0.006192 TL3.125 (R2 = 0.97) for females. Growth was expressed in length and the von Bertalanffy growth parameters were estimated as L = 354.9 mm, k = 0.0038, t0 = −26.82 for males and L = 339.0 mm, k = 0.0043, t0 = −24.88 for females. Growth performance indexes were also estimated as Φ′ = 6.17 for males and Φ′ = 6.20 for females. The gonadosomatic index showed that peak reproduction occurred during April and June, with highest average values of 2.1% for males and 25.3% for females in May. Oocyte diameter ranged from 0.09 to 1.58 mm, with a mean value of 0.54 ± 0.42 mm.

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