Biological Aspects of the Thicklip Grey Mullet (Chelon labrosus) in Bardawil Lagoon, Egypt

Shalloof, Kariman Ahmed Shawky; El- Aiatt, Attia; Ali, Shimaa; Ali Omar, Mohamed Attia

doi:10.21608/ejabf.2025.431652.6765

Biological Aspects of the Thicklip Grey Mullet (Chelon labrosus) in Bardawil Lagoon, Egypt

Document Type : Original Article

Authors

¹ Fisheries biology Lab. National Institute of Oceanography and Fisheries(NIOF), Egypt

² Fisheries Biology Lab. National Institute of Oceanography and Fisheries, Egypt.

³ Lakes and Fish Resources Protection and Development Agency (LFRPDA)

⁴ Lakes and Fish Resources Protection and Development Agency (LFRPDA

10.21608/ejabf.2025.431652.6765

Abstract

Despite its ecological and economic importance, information on the reproductive biology of the thicklip grey mullet C. labrosus in Bardawil Lagoon, North Sinai, Egypt remains limited. This study investigated key biological aspects of the species, including its length-weight relationship, condition factors, and reproductive biology, with emphasis on spawning season and length at first sexual maturity. A total of 472 individuals were monthly collected from various landing sites around Bardawil Lagoon, during the fishing season from May to December 2023. The length–weight relationships for C. labrosus showed isometric growth patterns for males, females, and both sexes combined. The monthly condition factor (K) values fluctuated over the course of the study period. The reproductive period, as indicated by the gonado-somatic index (GSI), was determined to occur during November and December. The overall sex ratio of males to females (M: F) was 1:1.4, indicating a predominance of females in the population. The length at first sexual maturity (L_m) was estimated to be 25.3cm for both males and females. Absolute fecundity showed an increase with total length and was modeled by the power function F_abs = 0.0264 W^2.20. Meanwhile, relative fecundity steadily rose, ranging from 356 to 1,420 eggs per centimeter and from 30.1 to 75.5 eggs per gram. To protect C. labrosus population in Bardawil Lagoon, it is recommended to prohibit the use of fishing gear with illegal mesh sizes and other destructive methods. Increasing the mesh size to selectively target fish larger than 25.3cm would help ensure that individuals have the opportunity to reproduce before being caught.

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