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

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.

Reproductive biology of Lagocephalus scelertaus in Mediterranean and Red Seas, Egypt

“…So, the GSI is almost higher for females than males, particularly during spawning season which is opposite to Gulf of Suez population result. Such finding was reported for some fishes such as the round herring Etrumeus teres by El-Sayed (1996);Farrag (2010) and Osman et al (2011).…”

Observations on the biology and seasonal variation in feeding of the east coast round herring Etrumeus wongratanai (Clupeiformes), off Scottburgh, KwaZulu‐Natal, South Africa

“…The eggs of E. wongratanai have been seen in small numbers throughout summer off the east coast of South Africa, with peaks in abundance being observed from June to December (Connell, 2001). Winter spawning of E. wongratanai agrees with observations by Farrag (2010) and Osman et al (2011), who suggested that spawning E. golanii need a higher energy input in order to meet the physiological demands of reproduction (Froese & Pauly, 2000). Observations on the condition factor of E. wongratanai are in accordance with such for E. golanii (Fahay, 1983;Shaw & Drullinger, 1990).…”

“…The length at first maturity of E. wongratanai is greater than that of E. golanii in the Mediterranean Sea (El‐Sayed, ; Osman et al ., ), but smaller than that of (males) E. golanii in the Gulf of Suez (Table ; Sanders et al ., ). Differences in length at maturity between studies on the same species (Table ) probably depend on the environmental conditions under which maturation takes place and the nature of the population (density‐dependent growth) when length at maturity is determined.…”

“…Winter spawning of E. wongratanai agrees with observations by Farrag () and Osman et al . (), who suggested that spawning E. golanii need a higher energy input in order to meet the physiological demands of reproduction (Froese & Pauly, ). Observations on the condition factor of E. wongratanai are in accordance with such for E. golanii collected in the Egyptian Mediterranean Sea, which were in poorest condition during the winter and spring when spawning.…”

“…Mketsu () noted that fish eggs and large crustacean zooplankton dominated the diet of E. wongratanai and that this species fed on larger prey items than either sardine (Clupeidae) or anchovy (Engraulidae), but on particles of similar size to those consumed by E. whiteheadi in areas where they co‐occurred. This is in contrast to the situation for E. whiteheadi and E. golanii (in the Mediterranean Sea), where work has been conducted on age and growth (Farrag et al ., ; Geja et al ., ; Geldenhuys, ; Waldron et al ., ; Yilmaz & Hossucu, ), diet (James, ; Mketsu, ; Osman et al ., ; Wallace‐Fincham, ) and reproduction (Roel & Melo, ; Osman et al ., ).…”