Some aspects of the biology of a cyprinid, Aspius vorax Heckel |
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| Authors: | M Shafi B M Jasim |
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| Institution: | Natural History Research Centre, University of Baghdad, Iraq;Department of Biology, College of Science, University of Baghdad, Iraq |
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| Abstract: | Scales were used for the determination of age with back-calculation of length. The oldest fish was VII + years old. Back-calculation did not exhibit Lee's phenomenon. The most rapid growth occurred in summer at water temperatures over 25°C. The growth in weight was c . 331 g year-1 after IV vears of life. Growth was well described by von Bertalanffy equation : ll - 91·0 l= 0·122(l0·25)] The length-weight relationship followed the cube law (b = 3·0601) Kn ranged from 0·74 to 1·18 with a mean value of 1·0. Spawning occurred in January, fecundity was 74 509 with a mean of 1157 eggs -1 body weight. Mean diameter of eggs was 1071 (pm). A developed ovary had ova of two sizes, immature oocytes and mature ova. The fish is a carnivorous feeder. |
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