SOME BIOLOGICAL ASPECTS OF GENUS CHRYSICHTHYS IN THE EGYPTIAN INLAND WATERS | ||
| Egyptian Journal of Aquatic Biology and Fisheries | ||
| Article 13, Volume 7, Issue 3, June 2003, Pages 259-277 PDF (1.5 M) | ||
| Document Type: Original Article | ||
| DOI: 10.21608/ejabf.2003.1778 | ||
| Authors | ||
| Shnoudy Bakhoum; Mohamed Ahmed | ||
| National Institute of Oceanography and Fisheries, Alexandria, Egypt | ||
| Abstract | ||
| Meristic and morphometric analyses were used to compare Chrysichthys auratus auratus, Chrysichthys auratus longifilis and Chrysichthys rueppelli from commercial catch of River Nile (Al Minya) and El-Nozha Hydrodrome (Alexandria), A total of twenty-nine separate body measurements and counts were taken from each fish. Significant differences were found between Chrysichthys auratus auratus and Chrysichthys auratus longifilis in 4 out of 29 examined characters. These characters were: maximum dorsal rays height, standard length, prepelvic length and dorsal base length. Specific variations revealed that C. auratus differed from C rueppelli significantly in eighteen out of twenty-nine examined characters. The univariate and multivariate analyses . indicated that C. rueppelli was defined from G auratus as the first has larger standard length, relatively short first dorsal fin ray; larger head width; longer upper and lower jaws lengths and caudal peduncle, pectoral fin and prepelvic lengths are longer than that of C. auratus. Discriminate function analysis showed that the percent correct site allocation were 96% for C. auratus auratus, 61% for C auratus longifilis and 92% for. C. rueppelli. All analyses suggested that Chrysichthys auratus and Chrysichthys rueppelli are distinct species. The relative abundance of these species revealed that C. auratus auratus dominated the catch by number in both regions. Length-weight relationship and condition factor indicated that C auratus auratus and C. auratus longifilis inhabiting El-Nozha Hydrodrome are heavier than those from. River Nile. In addition, the natural mortality coefficient for examined species inhabiting in El-Nozha Hydrodrome was comparatively lower than those from River Nile. | ||
| Keywords | ||
| Chrysichthys auratus auratus; C. auratus longifilis; C. rueppelli; Biometric; Length-weight relationship; coefficient of condition; Natural mortality | ||
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