Species Diversity in the Suez Canal
77
Suez Canal with typical and impoverished hyperhaline lagoons such as Laguna
Madre or Sivash (Hedgpeth, 1957).
The Canal is a marine-metahaline environment. The species are almost exclusively of marine origin, however, the diversity is reduced because of a combination of high salinity-Iow temperature, adverse bottom and turbidity conditions.
This is a typical metahaline situation. There are several animal groups in which
the hyperhaline-estuarine species are also fairly weIl represented: fish, decapods,
and copepods, as weIl as nematodes (Riemann and Rachor, 1972). Some taxa, such
as Nemertes, Acarina, and Tanaidacea, etc. have still not been investigated. Because of the shallowness of the Canal system, animals living on deep bottoms are
missing from the Canal fauna. The dearth ofthe plankton is however, a phenomenon much less suspected at ftrst sight. Some typically holoplanktonic groups are
missing from the Canal waters and the Canal lakes, for example Radiolaria,
Foraminifera, Siphonophora, Ctenophora, planktonic Polychaeta, Myodocopid
Ostracoda, Hyperiidea, Euphausiacea, Pteropoda, Heteropoda, Appendicularia,
and Thaliacea.
Among the planktonic larvae no Echinodermata have ever been found in the
Canal waters.
Holoplanktonic groups with a very restricted number of representatives in the
Canal are Dinoflagellata, Tintinnida, Chaetognatha, Copepoda, and Cladocera.
Among the Dinoflagellata, Halim (1963), Kimor (1972), and Dowidar (1973)
report Ceratium furca, Ceratium aegyptiacum and Ceratium eupulchellum. There
are two tintinnids, Tzntinnopsis beroidea and T.radix (Kimor, 1972). Burfteld
(1927) lists three arrow worms: Sagitta enflata, S. neglecta, and the neritic Spadella
cephaloptera; there are no newer reports. Gurney (1927 c) lists ten species of
Calanoida which appear in the Canal waters, another ftve species were limited to
the Canal entrances. From the Cyclopoida only Oithona nana spread in the Canal
and from the Harpacticoida Microsetella norvegica and Euterpina acutifrons. Corycaeidae were found only in a few scattered specimens and no Sapphirinidae and
Copilia were found.
Gurney (1927 c) reports the Cladocera Penilia avirostris and Evadne tergestina; Kimor (1972) adds the remarkable Bosmina coregoni maritima, an estuarine
cladoceran of freshwater origins. Among the Decapoda the planktonic Lud/er
hanseni is found in the Lakes. In sam pIes from December 1973 from the Great
Bitter Lake, I found many specimens of Praniza larvae of gnathiid isopods and
also Microniscus larvae.
The larval plankton is domina ted by the swarms of nauplü of Balanus. Gurney
(1927 a) found larvae of Penaeidae, Alpheidae of Palaemonidae, of Diogenes pugilator and of Leucosia signata, all species also reaching maturity in the Canal
system.
Schmidt (1972) considers that only the Hydrozoa with meroplanktonic larvae
live in the Suez Canal and that therefore, they spread by means of short-lived
medusae through the Canal.
Among the "epibenthic" planktonic organisms the Mysidacea are fairly common (Tattersal, 1927; Bäcescu, 1973).
Kimor (1972) considers that the poor plankton of the Suez Canal is composed
of euryhaline species, similar to those in estuarine environments, such as the
77
Suez Canal with typical and impoverished hyperhaline lagoons such as Laguna
Madre or Sivash (Hedgpeth, 1957).
The Canal is a marine-metahaline environment. The species are almost exclusively of marine origin, however, the diversity is reduced because of a combination of high salinity-Iow temperature, adverse bottom and turbidity conditions.
This is a typical metahaline situation. There are several animal groups in which
the hyperhaline-estuarine species are also fairly weIl represented: fish, decapods,
and copepods, as weIl as nematodes (Riemann and Rachor, 1972). Some taxa, such
as Nemertes, Acarina, and Tanaidacea, etc. have still not been investigated. Because of the shallowness of the Canal system, animals living on deep bottoms are
missing from the Canal fauna. The dearth ofthe plankton is however, a phenomenon much less suspected at ftrst sight. Some typically holoplanktonic groups are
missing from the Canal waters and the Canal lakes, for example Radiolaria,
Foraminifera, Siphonophora, Ctenophora, planktonic Polychaeta, Myodocopid
Ostracoda, Hyperiidea, Euphausiacea, Pteropoda, Heteropoda, Appendicularia,
and Thaliacea.
Among the planktonic larvae no Echinodermata have ever been found in the
Canal waters.
Holoplanktonic groups with a very restricted number of representatives in the
Canal are Dinoflagellata, Tintinnida, Chaetognatha, Copepoda, and Cladocera.
Among the Dinoflagellata, Halim (1963), Kimor (1972), and Dowidar (1973)
report Ceratium furca, Ceratium aegyptiacum and Ceratium eupulchellum. There
are two tintinnids, Tzntinnopsis beroidea and T.radix (Kimor, 1972). Burfteld
(1927) lists three arrow worms: Sagitta enflata, S. neglecta, and the neritic Spadella
cephaloptera; there are no newer reports. Gurney (1927 c) lists ten species of
Calanoida which appear in the Canal waters, another ftve species were limited to
the Canal entrances. From the Cyclopoida only Oithona nana spread in the Canal
and from the Harpacticoida Microsetella norvegica and Euterpina acutifrons. Corycaeidae were found only in a few scattered specimens and no Sapphirinidae and
Copilia were found.
Gurney (1927 c) reports the Cladocera Penilia avirostris and Evadne tergestina; Kimor (1972) adds the remarkable Bosmina coregoni maritima, an estuarine
cladoceran of freshwater origins. Among the Decapoda the planktonic Lud/er
hanseni is found in the Lakes. In sam pIes from December 1973 from the Great
Bitter Lake, I found many specimens of Praniza larvae of gnathiid isopods and
also Microniscus larvae.
The larval plankton is domina ted by the swarms of nauplü of Balanus. Gurney
(1927 a) found larvae of Penaeidae, Alpheidae of Palaemonidae, of Diogenes pugilator and of Leucosia signata, all species also reaching maturity in the Canal
system.
Schmidt (1972) considers that only the Hydrozoa with meroplanktonic larvae
live in the Suez Canal and that therefore, they spread by means of short-lived
medusae through the Canal.
Among the "epibenthic" planktonic organisms the Mysidacea are fairly common (Tattersal, 1927; Bäcescu, 1973).
Kimor (1972) considers that the poor plankton of the Suez Canal is composed
of euryhaline species, similar to those in estuarine environments, such as the