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Elsayed Mohamed Ibrahim Younis

Professor

Professor of Ecophysiology of Fish

Sciences
2B 133 & 2B 117 Building 5
publication
Journal Article
2020

Analysis of reproductive biology and spawning season of the pink ear emperor Lethrinus lentjan, from marine ecosystem

Shamlo, Elsayed M. Younis 1, Nasser A. Al-Asgah 1, Abdel-Wahab A. Abdel-Warith 1,2, Mohamed H. Gabr 3, Fozi S. . 2020

A total of 593 samples of Lethrinus lentjan (Lacepede, 1802) were collected from the Red Sea, Jeddah, Saudi Arabia, to study their productive biology and spawning season of the local population. Sampling was carried out on a monthly basis for a period of one year. The monthly sex ratios indicated that females were dominant throughout the study period, with an overall male:female sex ratio of 1:7.98, although males were larger than females. The highest monthly performance maturation index (PMI), as well as the male and female gonadosomatic index (GSI) and ovarian maturation rate (OMR) were observed in February and March. Histological examination of the gonads confirmed the process of sexual transformation in this fish species, wherein individuals mature first as female, and then change sex to male (protogynous hermaphroditism). Histological sections also showed that the sexual maturation of males of L. lenjtan comprised three main stages, while the sexual development of females could be classified into four main stages. Extended spawning in the form of batches released during different months throughout the year were recorded for this fish species, with the main spawning season in February and March, and an additional, shorter spawning season in September

Volume Number
37
Magazine \ Newspaper
ZOOLOGIA
Pages
1 - 10
more of publication
publications
by El-Sayed Hemdan Eissa1♦, Ehab El-Haroun2, Abdel-Wahab A. Abdel-Warith3, Elsayed M. Younis3, Simon J. Davies4, El Sayed A.E. Hamed5, Yasmin M. Abd El-Aziz6, Ola Hasan Abd El Megeed7, Hagar Sedeek Dighiesh8, Moaheda E.H. Eissa9, Hamdy Omar Ahmed5
2025
publications
by Ali Ali El-Raghi1♦, Ibrahim A. Abu El-Naser1, Asem A. Amer2, Abdel-Wahab A. Abdel-Warith3, Elsayed M. Younis3, Simon J. Davies4, Ahmed F. Fath El-Bab1♦
2025
publications
by Rowida E. Ibrahim · Abdelwahab A. Abdelwarith · Elsayed M. Younis · Amany Abdel‑Rahman Mohamed · Tarek Khamis · Ali Osman · Mohamed M. M. Metwally · Simon J. Davies · Yasmina M. Abd‑Elhakim
2025