86
The Suez Canal
permanent seepage. Salinity fluctuates between 45%0 and 60%0 and winter temperature may be as low as 10° C. Nevertheless, among the relatively few species
which live in this peculiar and extreme environment we can still find several
species common also in the Suez Canal: Diodora rüppelli and Ancillaria cinnamomea, a small cowrie-like snail, as weH as the medusa Cassiopea andromeda, the
isopod Cymodoce truncata and the red alga Laurencia papillosa.
All the coastal shallows of the Red Sea may be considered as a metahaline
area, with salinities reaching 45--46%0. This was evidenced for the fIrst time by
Remane and Schulz (1964) who briefly discussed the growths of Digenea simplex
at Al Ghardaqa.
The Persian Gulf has extensive areas of high salinities along its southern
shores. The biota of the Gulf shows a gradual depletion with increasing salinity, a
"restriction" as termed by Purser and Seibold (1973). The restriction in the fauna
is shown in the open waters of the Gulf where such Indo-PacifIc genera as Tridacna or Lambis do not occur. According to Hughes and Kay (1973), Conus and
Strombus, all the pectinid sheHs and almost all of the sea urchins disappear at
salinity values of 45%0. Of all the coral species only Porites advances to 48%0.
However, marine biota can be still found at higher salinities. Among them are
many ofthe Suez Canal species. According to Kessler (1973) the sea star Asterina
wega, Astropecten (probably irregularis) and an unidentified brittle star can still be
found at > 50%0 in Ghor al Bazam.
In the Abu Dhabi lagoon Evans et al. (1973) report aquatic plants such as
Halophila stipulacea, Halodule uninervis, Jania sp. and Acetabularia sp. from salinities reaching 50%0. Several species of molluscs still live on the intertidal flats of
the inner lagoon with salinities of 53.6-66.9%0, among them Cerithium scabridum,
Brachidontes variabilis and Pirenella conica. It is interesting to note that the most
salinity-resistant of the sea urchins on the Abu Dhabi shore is Echinometra mathaei, which lives at salinities of 42.7-44.5%0, a similar situation to that in the
northern Gulf ofSuez.
The coastal metahaline environments of the Indian Ocean and the adjacent
seas, the Red Sea and the Persian Gulf, are still insuffIciently investigated. It seems,
however, reasonable to assume that more and more species known in the Suez
Canal will be found also in these other high salinity environments. It is evident
that large parts of the Canal fauna are in fact species which were "adaptative1y
ready" to invade the artifIcial metahaline environment built by de Lesseps.
The Suez Canal
permanent seepage. Salinity fluctuates between 45%0 and 60%0 and winter temperature may be as low as 10° C. Nevertheless, among the relatively few species
which live in this peculiar and extreme environment we can still find several
species common also in the Suez Canal: Diodora rüppelli and Ancillaria cinnamomea, a small cowrie-like snail, as weH as the medusa Cassiopea andromeda, the
isopod Cymodoce truncata and the red alga Laurencia papillosa.
All the coastal shallows of the Red Sea may be considered as a metahaline
area, with salinities reaching 45--46%0. This was evidenced for the fIrst time by
Remane and Schulz (1964) who briefly discussed the growths of Digenea simplex
at Al Ghardaqa.
The Persian Gulf has extensive areas of high salinities along its southern
shores. The biota of the Gulf shows a gradual depletion with increasing salinity, a
"restriction" as termed by Purser and Seibold (1973). The restriction in the fauna
is shown in the open waters of the Gulf where such Indo-PacifIc genera as Tridacna or Lambis do not occur. According to Hughes and Kay (1973), Conus and
Strombus, all the pectinid sheHs and almost all of the sea urchins disappear at
salinity values of 45%0. Of all the coral species only Porites advances to 48%0.
However, marine biota can be still found at higher salinities. Among them are
many ofthe Suez Canal species. According to Kessler (1973) the sea star Asterina
wega, Astropecten (probably irregularis) and an unidentified brittle star can still be
found at > 50%0 in Ghor al Bazam.
In the Abu Dhabi lagoon Evans et al. (1973) report aquatic plants such as
Halophila stipulacea, Halodule uninervis, Jania sp. and Acetabularia sp. from salinities reaching 50%0. Several species of molluscs still live on the intertidal flats of
the inner lagoon with salinities of 53.6-66.9%0, among them Cerithium scabridum,
Brachidontes variabilis and Pirenella conica. It is interesting to note that the most
salinity-resistant of the sea urchins on the Abu Dhabi shore is Echinometra mathaei, which lives at salinities of 42.7-44.5%0, a similar situation to that in the
northern Gulf ofSuez.
The coastal metahaline environments of the Indian Ocean and the adjacent
seas, the Red Sea and the Persian Gulf, are still insuffIciently investigated. It seems,
however, reasonable to assume that more and more species known in the Suez
Canal will be found also in these other high salinity environments. It is evident
that large parts of the Canal fauna are in fact species which were "adaptative1y
ready" to invade the artifIcial metahaline environment built by de Lesseps.