Fish in the Gulf of Eilat

The Red Sea (Gulf of Aqaba) is considered a "hotspot" for fish species, supporting rich biodiversity, many endemic and unique species, and species that are "new" from an evolutionary perspective (DiBattista et al., 2016). Currently, over 1,280 fish species are recorded in the Red Sea, with 12.9% being endemic to the Red Sea and 14.1% being endemic to both the Red Sea and the Gulf of Aden (Goren, 1993; Khalaf, 2004; Khalaf & Kochzius, 2002; Golani & Bogorodsky, 2010; DiBattista et al., 2016). Among the coral reef fish species inhabiting the Arabian Sea, 69% have crossed into and established themselves in the Red Sea, with 55% successfully establishing themselves in the Gulf of Aqaba (Kiflawi et al., 2006).

In the Gulf of Aqaba, approximately 507 fish species from 109 families have been documented, averaging 4.7 species per family. Of these, 18 species belong to cartilaginous fish (Chondrichthyes) and 489 to bony fish (Osteichthyes). The dominant fish families in the Gulf, which constitute about 40.8% of all species, include: Labridae (51 species), Pomacentridae (29 species), Serranidae (25 species), Apogonidae (24 species), Blenniidae (24 species), Gobiidae (21 species), Carangidae (17 species), and Syngnathidae (16 species) (Khalaf, 2004).

The distribution of fish species between benthic habitats (associated with the seabed and substrate) and pelagic habitats (in the water column) in the Gulf of Aqaba is shown in Table 1, while for the entire Red Sea, it is presented in Table 2. Focusing on the Gulf of Aqaba, most fish species (82.8%) live in benthic habitats, with 1.7% of species living in the deep sea and the remaining species being pelagic fish (Khalaf, 2004; Stambler, 2013). Fish survey data indicates that fish communities along the entire Saudi Arabian coastline (DiBattista et al., 2016) and the northern Gulf of Aqaba (Shaked & Genin, 2023) show similar community structures.

Reports from the national monitoring program in the Gulf of Aqaba, which has conducted fish surveys since 2007, indicate that fish communities at research sites and nature reserves in the northern Gulf of Aqaba have remained stable in terms of species composition, species richness, trophic levels (dietary levels), and fish biodiversity throughout the monitoring years (Shaked & Genin, 2023).

One of the significant differences in fish communities between the Red Sea and the Gulf of Aqaba is the deep-sea fish species. The entry of deep-sea fish from the Red Sea into the Gulf of Aqaba is limited by the shallow Strait of Tiran (~252 m), which has led to the development of secondary deep-sea fish communities isolated within the Gulf of Aqaba. Consequently, the Gulf of Aqaba is considered a unique zoogeographic zone within the Red Sea (Kochzius, 2002 and references therein).

Fish trophic levels have been studied in the northern Gulf of Aqaba, with findings that approximately 30.6% of fish species feed on fish and invertebrates, while 24.8% feed solely on invertebrates. Planktivorous fish species make up about 15.9%. Additionally, around 15% of species are omnivores, 7.4% are herbivores, 4.5% are piscivores, 1.6% feed on corals (corallivores), and 0.5% are detritivores (Kochzius, 2002; Khalaf, 2004).

Table 1. Distribution of fish species between various benthic and pelagic habitats in the Gulf of Aqaba (Khalaf, 2004).

Table 2. Distribution of fish species between benthic and pelagic habitats in the Red Sea (Golani & Bogorodsky, 2010; Stambler, 2013).

Bibliography

DiBattista, J. D., Roberts, M. B., Bouwmeester, J., Bowen, B. W., Coker, D. J., Lozano‐Cortés, D. F., … & Berumen, M. L. (2016). A review of contemporary patterns of endemism for shallow water reef fauna in the Red Sea. Journal of Biogeography, 43(3), 423-439. doi:10.1111/jbi.12649.

Golani, D. & Bogorodsky, S.V. (2010). The Fishes of the Red Sea -Reappraisal and updated checklist. Zootaxa, 2463: 1-135.

Goren, M. (1993). Statistical aspects of the Red Sea ichthyofauna. Israel Journal of Zoology 39: 293-298.

Khalaf, M. (2004). Fish fauna of the Jordanian coast, Gulf of Aqaba, Red Sea. Marine Scienes, 15(1).

Khalaf, M. A., & Kochzius, M. (2002). Community structure and biogeography of shore fishes in the Gulf of Aqaba, Red Sea. Helgoland marine research, 55, 252-284.

Kiflawi, M., Belmaker, J., Brokovich, E., Einbinder, S., & Holzman, R. (2006). The determinants of species richness of a relatively young coral‐reef ichthyofauna. Journal of biogeography, 33(7), 1289-1294.

Kochzius, M. (2002). Ecology, genetic population structure, and molecular phylogeny of fishes on coral reefs on the Gulf of Aqaba and northern Red Sea (Doctoral dissertation, PhD thesis. University of Bremen, Bremen, Germany).