Reproductive Dynamics of Indian Squid, Uroteuthis duvaucelii (Cephalopoda: Loliginidae) of the Suez Gulf, Red Sea, Egypt | ||||
| Egyptian Journal of Aquatic Biology and Fisheries | ||||
| Article 35, Volume 25, Issue 5, September and October 2021, Page 573-589 PDF (1.26 MB) | ||||
| Document Type: Original Article | ||||
| DOI: 10.21608/ejabf.2021.204360 | ||||
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| Author | ||||
| Wessam E. R. Elsayed et al. | ||||
| Abstract | ||||
| The overall pattern of the reproduction of the commercially important Indian squid, Uroteuthis duvaucelii in the Suez Gulf was described in terms of sex ratio, mantle length at 50% maturity, gonado-somatic index as well as the morphological and histological changes in gonads of both males and females. The overall sex ratio (M: F) was 1.7:1 showing the dominance of males over females during the study period. Males grow to a larger size compared to females (maximum ML= 25.3 and 19.4 cm for males and females, respectively). But, females reach sexual maturity earlier than males (ML50% = 13.5 and 10 cm ML for males and females, respectively). The gonado-somatic index values increased with the gonad maturation, having 2 beaks during spring (in April for both males and females) and autumn (in November for females and in October for males) and declined thereafter during winter. Thus, the reproductive period occurs frequently throughout the year, especially in warm months. Four stages (I - IV) of maturity were recognized according to their macroscopic appearance. No spent (stage V) individuals were observed morphologically throughout the study. The histological evaluation showed five stages (I – V) of gonadal development in males’ testis. While six stages (I – VI) were determined in the female’s ovary. The appearance of various stages of gonadal development at the same time in most histological slides indicates that the spawning strategy in this species is iteroparous and spawns partially throughout the year. These findings regarding the reproductive dynamics of U. duvaucelii in the Suez Gulf are very important for preserving its stock and regulating its fishing strategies | ||||
| Keywords | ||||
| Cephalopods; Squid; Uroteuthis duvaucelii; Suez Gulf; Sex ratio; Sexual maturity; Gonado-somatic index; Reproductive cycle; Spawning pattern | ||||
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