Mediterranean Marine Science Vol. 12, 2011 Aliens in Egyptian Mediterranean waters. A check- list of Erythrean fish with new records HALIM Y. Department of Oceanography, Faculty of Science, Alexandria University RIZKALLA S. National Institute of Oceanography and Fisheries, Alexandria https://doi.org/10.12681/mms.46 Copyright © 2011 To cite this article: HALIM, Y., & RIZKALLA, S. (2011). Aliens in Egyptian Mediterranean waters. A check-list of Erythrean fish with new records. Mediterranean Marine Science, 12(2), 479-490. doi:https://doi.org/10.12681/mms.46 http://epublishing.ekt.gr | e-Publisher: EKT | Downloaded at 08/05/2021 22:23:14 | Mediterranean Marine Science Research Article Indexed in WoS (Web of Science, ISI Thomson) and SCOPUS The journal is available on line at http://www.medit-mar-sc.net Aliens in Egyptian Mediterranean waters. A check-list of Erythrean fish with new records Y. HALIM1 and S. RIZKALLA2 1 Department of Oceanography, Faculty of Science, Alexandria University 2 National Institute of Oceanography and Fisheries, Alexandria Corresponding author: [email protected] Received: 21 January 2011; Accepted: 5 October 2011; Published on line: 25 November 2011 Abstract The historical role of the Suez Canal as a pathway for migrations between the Red sea and the Mediterranean is recalled. A check-list of 42 immigrant Erythrean fish in Egyptian Mediterranean waters is given. The list comprises four new records. 17 of the immigrant species are commercially exploited, whereas 15 are known from single records. While the Erythrean fish as invasive species are beneficial to local fisheries, in our view, they do not have an important impact upon the ecosystem. Keywords: Suez Canal; Invasive species; Ecosystems; Impacts; Benefits; Biodiversity. Introduction MORCOS (1980) compared the water mass- es in the Canal in 1955 to the records made The biodiversity of the East Mediter- in 1871, two years after its opening and found ranean has been considerably altered since that salinity dropped from about 65 ppm to the opening of the Suez Canal in 1869. As about 45ppm. Nevertheless, the circulation a narrow and shallow water course, it stands pattern remained unchanged, the residual as a channel between two marine basins current tending to flow from the Red Sea to (GRUVEL, 1936). Its biological role how- the Mediterranean for ten months, revers- ever, is out of proportion to its size, although ing its flow in August-September. This pat- as a habitat and a pathway it remained long tern, added to their greater tolerance to high inhospitable to marine organisms. Two op- salinity, favours the northward migration of posite salinity barriers, the abnormally high Erythrean organisms. salinity of the Bitter Lakes, south, and the The process of immigration into and Nile dilution, north, stood on their way. With through the Canal remained incremental the continuous dissolution of the salt beds but slow, as documented by the early sur- in the Lakes and the cessation of the Nile veys of its ichthyofauna. Some ten years flood, both barriers became weaker. after its opening, KELLER (1882) found 12 Medit. Mar. Sci., 12/2, 2011, 479-490 479 http://epublishing.ekt.gr | e-Publisher: EKT | Downloaded at 08/05/2021 22:23:14 | fish species in the Canal and shortly after, Exotic fish species in the Mediterranean, KRUKENBERG (1888) recorded 15 species GOLANI et al. (2002) reported 59 exotic (for KRUKENBERG 1888 see NORMAN, species for an estimated Mediterranean to- 1927). TILLIER in 1902 published a de- tal of 650, which is almost 10% of the pop- tailed account of the ichthyofauna of the ulation. The rate of fish invasion has con- Canal based on a survey extending over sev- tinued unabated since 2002 (GOLANI et al., eral years. He recorded 80 species of which 2002). By 2007, 18 new alien fish species have about 40 occurred in the Canal, the others been recorded and many have extended their presumably venturing in and out. area of distribution (GOLANI et al., 2007). NORMAN (1927), working on the col- By 2010, their number in the updated CIESM lection made by the Cambridge Expedi- check list (GOLANI et al., 2010) had reached tion to the Suez Canal in 1924, reported 23. A further 17 alien species recorded in the occurrence of 45 fish species, 24 orig- 2009 figure on the list but with no indication inated from the Red Sea and 21 from the about biogeographic affinity. The check list Mediterranean. From his records and from of ZENETOS et al. (2010) comprises 92 alien more recent observations, it appears that species of Indo-Pacific origin in the East 13 of the Red Sea species had already es- Mediterranean. tablished viable populations in the Mediter- As to Egyptian waters, the check list ranean . On the other hand, five the Mediter- of EL SAYED (1994) included 31 Erythre- ranean species such as Engraulis encrassi- an fish species out of a total of 257. After cholus (Linnaeus, 1758), Hippocampus bre- EL SAYED (1994) and taking into account virostris (Schinz, 1822), Serranus cabrilla earlier records (NORMAN, 1927; MILLER (Linnaeus, 1785), Gobius ocheticus (Nor- & FOUDA, 1986) and more recent ones man, 1926) and Epinephelus aeneus (Ge- (RIZKALLA, 1997; ALLAM et al., 1999; offroy Saint-Hilaire, 1817), succeeded in GAMEE, 2005), Erythrean fish accounted crossing the Bitter Lakes establishing in for 38 species. Two species reported from the Gulf of Suez. Egyptian waters by TORTONESE (1951), The important changes that took place Glaucostegus halavi (Forsska l, 1775) and in the Levantine basin following the com- Carcharhinus melanopterus (Quoy & Gaimard, pletion of the High Aswan Dam in 1965-67 1824) have been omitted as their occurrence have created more favourable conditions for has not been confirmed. the settlement and spread of Erythrean fish The present work adds four new records and invertebrates in the Mediterranean basin of Erythrean fishes being present along the (HALIM et al., 1995; HALIM, 2004). In- Mediterranean Egyptian coasts, bringing the stead of reaching a plateau as POR (1978) list to a total of 42 species. Information on assumed, the process appears to be accel- their contribution to fishery is also given. erating. Later, POR himself reviewed his earli- Material and Methods er statement (POR, 1990). TORTONESE (1964) estimated the Indo-Pacific immigrant The present check-list of Erythrean fish fish species to be about 30 for a Mediter- species in Egyptian waters combines dis- ranean total of about 550. BEN-TUVIA persed records reported by several authors (1985) listed 41 species including the records over the years but it also includes recent, un- of MOUNEIMNE (1977). In their Atlas of published records made by the second au- 480 Medit. Mar. Sci., 12/2, 2011, 479-490 http://epublishing.ekt.gr | e-Publisher: EKT | Downloaded at 08/05/2021 22:23:14 | thor (S. RIZKALLA). Species are sorted phus far, and seven carnivores or omnivores, according to the observed abundance and namely, Etrumeus teres, Fistularia commer- the frequency of appearance in the fish mar- soni, Sphyraena chrysotaenia, Sphyraena flav- ket. Species which have established successful icauda, Parexocoetus mento, Scomberomorus viable populations are grouped under “A” commerson and Tylosurus choram and “B”. Species under A are of commer- As a rule, the new-comers to the Mediter- cial value and appear on the fish market, ranean tended to extend east rather than with the exception of the toxic Lagocephalus west from the Canal in the pre-High Dam sceleratus. “Single record” species are put times, a trend which is expected to change. under “C” since the frequency of the pres- Nevertheless, some Red Sea immigrants are ence in the fish market tends to be a func- now common hundreds of kilometres west tion of their economic value. The less valu- of Alexandria. This is the case with L. scel- able species are frequently overlooked, though eratus and F. commersonii (unpublished some might be fairly common. On the other records). On the other hand, some Erythrean hand the three groups should not to be con- fish proved to be highly euryhaline, tolerant sidered as rigid categories. Some species to a wide salinity range being able to pene- from group B such Fistularia commersonii trate the low brackish Delta lakes as well as and Hemiramphus far are on their way to de- the hypersaline Bardawil lagoon (Table 2, velop growing populations and will soon Fig. 1). need to be included under A. Three species Sebastapistes nuchalis (Günther, 1874), (Herklotsichthys punctatus, Siganus luridus which was excluded from the checklist of and Callionymus filamentosus) have been GOLANI et al. (2002) on the grounds that placed under category “A” following the sur- its single record in Cyprus was based on a vey of AKEL (2005) in Abu Qir bay. Two misidentification, is now included again in species namely Glaucostegus halavi (Forsska l, the list of alien Mediterranean species from 1775) and Carcharinus melanopterus reported a single record of EL SAYED, 1994. from Egyptian waters by TORTONESE New records. Four new Indo-Pacific (1951) have been omitted from the check species were encountered in samples col- list as their occurrence in Egyptian waters lected by the second author (S.R.) from has not been confirmed. trawlers, beach-seiners and purse-seiners Nomenclature follows the World Regis- from 2001 to 2009. Their description agrees ter of Marine Species (APPELTANS et al, with GOLANI et al. (2010). 2011). Family Fistularidae (Cornetfishes) Results Fistularia commersonii Rüppell, 1835 (Fig. 2). The Erythrean fish species recorded A relatively large number of specimens from Egyptian Mediterranean waters until (48-103 cm in total length) were caught in 2010 are given on Table 1. Apart from nine 2001 by trawlers west of Alexandria. The species, all of them are demersal, feeding species is so far absent from the eastern zone.