80
The Suez Canal
Nearer to the shore a sequence of plant communities typieal of other sheltered
areas of the Red Sea is found. From the shore downwards these are Digenea
simplex, Halophila stipulacea, Halodule uninervis, Cystoseira, and Sargassum spp.
The littoral fauna associated with these plants is also the fauna found everywhere
with them in the Red Sea. This so-called "Halophila fauna" and the neighboring
"litt oral boulder fauna" has been discussed to some extent in a previous paper
(Por, 1971 b) as being extremely characteristie of the Bitter Lakes and Lake Timsah. The similarity of the Canal lakes' biota, with those of the semienclosed
lagoons ofthe Northern Red Sea will be discussed below.
An impoverished fauna is found at the water level and in the belt corresponding to the intertidal, in the almost tideless canal water. Only those species of the
Red Sea and Mediterranean intertidal are found whieh can survive or even thrive
in sheltered environments. For instance, there are no representatives ofthe genus
Littorina (sensu latu), no Monodonta, nor the big barnacles of the genus Tetraclita.
Dominant there are Brachidontes variabilis, Diodora rüppelli, and Balanus amphitrite. Other species living in this belt are Crassostrea (cucculata?), Cellana rota,
Modiolus auriculatus, and Chthamalus (stellatus? ).
FinaIly, an important constituent ofthe Canal fauna is formed by the so-called
"phytal fauna". Especially frequent are animals living on algae and water plants,
and covering artificial substrates such as piers and buoys. These organisms partieipate in the fouling community found on ship hulls. Sponges, Hydrozoa, and
Ascidiacea belong to this category. As for the smaller fauna, Pycnogonida, Hydracarina, and Amphipoda are widespread. Among the harpactieoid Copepoda the
dominant ecological group is that of the phytal species (Por and Marcus, 1972).
Among the Ostracoda also, the phytal species Loxoconcha gardaqensis is the most
frequent (Lerner-Seggev, 1972). Of the ten species of Isopoda reported from the
Canal waters (Glynn, 1972) seven or eight are typieal of phytal habitats. Schellenberg (1928) in his exhaustive paper on the Suez Canal Amphipoda remarks the
almost complete absence of the forms whieh burrow in the substrate. On the other
hand, species "whieh climb among water plants and frxed animals" are weIl
represented.
The Great Bitter Lake has sometimes been seen as an extreme hypersaline
environment, with the connotation of low species diversity. Oren (1969) considered the Bitter Lakes as they were prior to 1924 "a solid barrier to the passage of
organisms". To Thorson (1971) the Great Bitter Lake through a combination of
hypersalinity with extreme high temperature (sie!) was an environment "problematie for adult animals and, probably, impossible for larvae". For a European
marine biologist the salinity values ofthe Great Bitter Lake were hypersaline, and
therefore beyond the range ofthe marine fauna. For the salinity-adapted Red Sea
fauna this is different.
Keller (1882) found the fauna ofthe Bitter Lakes to be richer than that of the
Bay of Suez. Fox (1929) concluded that the high salinity is not unfavorable to
certain forms of marine life, and that the faun!! of the Lakes is rich both in species
and numbers ofindividuals. The teeming life in the Bitter Lakes is still a matter of
surprise to everybody who visits its shores. In species diversity the Bitter Lakes
can be compared weIl to a shallow and mixed-bottom gulf of a tropieal sea.
The Suez Canal
Nearer to the shore a sequence of plant communities typieal of other sheltered
areas of the Red Sea is found. From the shore downwards these are Digenea
simplex, Halophila stipulacea, Halodule uninervis, Cystoseira, and Sargassum spp.
The littoral fauna associated with these plants is also the fauna found everywhere
with them in the Red Sea. This so-called "Halophila fauna" and the neighboring
"litt oral boulder fauna" has been discussed to some extent in a previous paper
(Por, 1971 b) as being extremely characteristie of the Bitter Lakes and Lake Timsah. The similarity of the Canal lakes' biota, with those of the semienclosed
lagoons ofthe Northern Red Sea will be discussed below.
An impoverished fauna is found at the water level and in the belt corresponding to the intertidal, in the almost tideless canal water. Only those species of the
Red Sea and Mediterranean intertidal are found whieh can survive or even thrive
in sheltered environments. For instance, there are no representatives ofthe genus
Littorina (sensu latu), no Monodonta, nor the big barnacles of the genus Tetraclita.
Dominant there are Brachidontes variabilis, Diodora rüppelli, and Balanus amphitrite. Other species living in this belt are Crassostrea (cucculata?), Cellana rota,
Modiolus auriculatus, and Chthamalus (stellatus? ).
FinaIly, an important constituent ofthe Canal fauna is formed by the so-called
"phytal fauna". Especially frequent are animals living on algae and water plants,
and covering artificial substrates such as piers and buoys. These organisms partieipate in the fouling community found on ship hulls. Sponges, Hydrozoa, and
Ascidiacea belong to this category. As for the smaller fauna, Pycnogonida, Hydracarina, and Amphipoda are widespread. Among the harpactieoid Copepoda the
dominant ecological group is that of the phytal species (Por and Marcus, 1972).
Among the Ostracoda also, the phytal species Loxoconcha gardaqensis is the most
frequent (Lerner-Seggev, 1972). Of the ten species of Isopoda reported from the
Canal waters (Glynn, 1972) seven or eight are typieal of phytal habitats. Schellenberg (1928) in his exhaustive paper on the Suez Canal Amphipoda remarks the
almost complete absence of the forms whieh burrow in the substrate. On the other
hand, species "whieh climb among water plants and frxed animals" are weIl
represented.
The Great Bitter Lake has sometimes been seen as an extreme hypersaline
environment, with the connotation of low species diversity. Oren (1969) considered the Bitter Lakes as they were prior to 1924 "a solid barrier to the passage of
organisms". To Thorson (1971) the Great Bitter Lake through a combination of
hypersalinity with extreme high temperature (sie!) was an environment "problematie for adult animals and, probably, impossible for larvae". For a European
marine biologist the salinity values ofthe Great Bitter Lake were hypersaline, and
therefore beyond the range ofthe marine fauna. For the salinity-adapted Red Sea
fauna this is different.
Keller (1882) found the fauna ofthe Bitter Lakes to be richer than that of the
Bay of Suez. Fox (1929) concluded that the high salinity is not unfavorable to
certain forms of marine life, and that the faun!! of the Lakes is rich both in species
and numbers ofindividuals. The teeming life in the Bitter Lakes is still a matter of
surprise to everybody who visits its shores. In species diversity the Bitter Lakes
can be compared weIl to a shallow and mixed-bottom gulf of a tropieal sea.