Table of Contents
ISRN Zoology
Volume 2011, Article ID 215950, 12 pages
http://dx.doi.org/10.5402/2011/215950
Research Article

Reproductive Biology of Round Herring Etrumeus teres (Dekay, 1842) from the Egyptian Mediterranean Water at Alexandria

1Department of Zoology, Faculty of Science, Al-Azhar University, Assiut Branch, Assiut 71524, Egypt
2Leibniz-Institute of Freshwater Ecology and Inland Fisheries, 12587 Berlin, Germany
3Fishery Biology Lab, National Institute of Oceanography and Fisheries, Kait-Bey, Alexandria, Egypt

Received 24 January 2011; Accepted 1 March 2011

Academic Editors: A. Pagano and A. Robins

Copyright © 2011 Alaa G. M. Osman et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Maturity stages of round herring Etrumeus teres were divided anatomically into six stages. Monthly distribution of such maturity stages showed that E. teres had prolonged spawning season extended from December to May for females and to July for males. The observed sex ratio was 1 : 2 (male: female). Gonadosomatic index (GSI) values were high during breeding season for both sexes. Hepatosomatic index (HIS) values for females increased from December to April and from December to July for males. Both sexes of E. teres showed the same correlation between GSI and HSI during their breeding season. The absolute and relative fecundity increased with increasing of length and weight. Histologically, the ovarian cycle of E. teres was classified into six stages and the testicular cycle into five stages. Female of E. teres was a multiple spawner and had prolonged spawning season with a group-synchronous ovarian which contained oocytes at all stages of development. Also, different sizes of spermatocytes at different developmental stages of maturation were observed during the same season. This may reflect the suitability of the specific reproductive behavior of male and its adaptation to the prolonged spawning season with females.