162
The Migrant Biota
species of Hydroida. There is no decapod crustacean in the list and the three
molluscs Chama gryphoides, Cerastoderma glaucum, and Nassa gibbosula are
known only from the outlet ofthe Canal at Port Taufiq and Suez.
I would like to separate the list into different categories according to criteria of
decreasing reliability.
1. Two species of estuarine, euryhaline fish, Dicentrarchus punctatus and Liza
aurata, have been found in relative abundance in the EI Bilaiyim lagoon
some 200 km south of Suez (Ben-Tuvia, 1971 b, 1975b). So far, these are
the only two cases which can be equated as counterparts of the Lessepsian migrants. The advance of these Mediterranean species through the Canal can
be followed, and they buHt up populations at a considerable distance from the
Canal. Several more fish species are caught around Suez: Sciaena aquilla, Umbrina cirrosa, Engraulis enchrassicolis, and Hippocampus brevirostris. Gohar (1954)
speaks of S. aquilla being caught in the Northern Gulf of Suez. The above mentioned molluscs belong to the same category of Mediterranean species which
progressed as far south as Port Taufiq, but no further into the Red Sea. Cerastoderma glaucum, the bivalve formerly called Cardium edule, has also reached the
lagoons of Suez, possibly in pre-Lessepsian times. The isopod Sphaeroma serraturn too is known to have reached Port Taufiq, but this is a euryhaline species
which could possibly have accompanied the other pre-Lessepsians.
An interesting case in itself is that of the fish Serranus cabrilla, which is
frequently caught in the Northern Red Sea. It is the only representative of this
Atlantic genus in the Red Sea and therefore it served as the first discussed example
of Mediterranean immigration. S. cabrilla was, however, found in the Southern
Red Sea by Kossman and Rauber in 1874-1875, and in the same period at Kosseir
in the Sudanese Red Sea by Klunzinger (1884). These dates are too early even for
a very successful migrant; therefore, the presence of Serranus cabrilla in the Red
Sea ought to be considered as prior to the opening of the Canal.
2. There are several species prone to be south-bound migrants through the
Suez Canal. They are known from the Suez Canal, but spread very rapidly and are
known from sites fairly remote from the Canal. Such is the isopod Cymodoce
truncata found all along the Sinai Coasts to the head of the Gulf of Elat (Glynn,
1972). Glynn considers that Cymodoce richardsoni reported by Nobili (1906) from
the waters of Eritrea in the Southern Red Sea is synonymous with C. truncata. In
this case the species was present in the Southern Red Sea as early as 1891-1896
when the two Italian expeditions on the "Scilla" took pI ace. Therefore Glynn
(1972) mentions C. truncata as a case of "rapid and successul colonization of the
Red Sea" (p.297). It was indeed rapid, if the species was not preexistent to the
opening of the Suez Canal. If this was not so, than the possibility of passive
transport should be held responsible.
Of the many Polychaeta listed as Mediterranean immigrants, only two are
known from the Suez Canal: Scalisetosus fragilis which has been found as far
south as Ghardaqa (Hartmann-Schröder, 1960) and Lumbrineris coccinea reported by Fishelson and Rullier (1969) from Musseri in the Southern Red Sea.
There are five species of Polychaeta found by Fauvel (1933) in the Gulf of
Suez, but not in the Canal. These are also candidates for an eventual rapid
passage through the Canal as adventives on ships or on other fouling organisms.
The Migrant Biota
species of Hydroida. There is no decapod crustacean in the list and the three
molluscs Chama gryphoides, Cerastoderma glaucum, and Nassa gibbosula are
known only from the outlet ofthe Canal at Port Taufiq and Suez.
I would like to separate the list into different categories according to criteria of
decreasing reliability.
1. Two species of estuarine, euryhaline fish, Dicentrarchus punctatus and Liza
aurata, have been found in relative abundance in the EI Bilaiyim lagoon
some 200 km south of Suez (Ben-Tuvia, 1971 b, 1975b). So far, these are
the only two cases which can be equated as counterparts of the Lessepsian migrants. The advance of these Mediterranean species through the Canal can
be followed, and they buHt up populations at a considerable distance from the
Canal. Several more fish species are caught around Suez: Sciaena aquilla, Umbrina cirrosa, Engraulis enchrassicolis, and Hippocampus brevirostris. Gohar (1954)
speaks of S. aquilla being caught in the Northern Gulf of Suez. The above mentioned molluscs belong to the same category of Mediterranean species which
progressed as far south as Port Taufiq, but no further into the Red Sea. Cerastoderma glaucum, the bivalve formerly called Cardium edule, has also reached the
lagoons of Suez, possibly in pre-Lessepsian times. The isopod Sphaeroma serraturn too is known to have reached Port Taufiq, but this is a euryhaline species
which could possibly have accompanied the other pre-Lessepsians.
An interesting case in itself is that of the fish Serranus cabrilla, which is
frequently caught in the Northern Red Sea. It is the only representative of this
Atlantic genus in the Red Sea and therefore it served as the first discussed example
of Mediterranean immigration. S. cabrilla was, however, found in the Southern
Red Sea by Kossman and Rauber in 1874-1875, and in the same period at Kosseir
in the Sudanese Red Sea by Klunzinger (1884). These dates are too early even for
a very successful migrant; therefore, the presence of Serranus cabrilla in the Red
Sea ought to be considered as prior to the opening of the Canal.
2. There are several species prone to be south-bound migrants through the
Suez Canal. They are known from the Suez Canal, but spread very rapidly and are
known from sites fairly remote from the Canal. Such is the isopod Cymodoce
truncata found all along the Sinai Coasts to the head of the Gulf of Elat (Glynn,
1972). Glynn considers that Cymodoce richardsoni reported by Nobili (1906) from
the waters of Eritrea in the Southern Red Sea is synonymous with C. truncata. In
this case the species was present in the Southern Red Sea as early as 1891-1896
when the two Italian expeditions on the "Scilla" took pI ace. Therefore Glynn
(1972) mentions C. truncata as a case of "rapid and successul colonization of the
Red Sea" (p.297). It was indeed rapid, if the species was not preexistent to the
opening of the Suez Canal. If this was not so, than the possibility of passive
transport should be held responsible.
Of the many Polychaeta listed as Mediterranean immigrants, only two are
known from the Suez Canal: Scalisetosus fragilis which has been found as far
south as Ghardaqa (Hartmann-Schröder, 1960) and Lumbrineris coccinea reported by Fishelson and Rullier (1969) from Musseri in the Southern Red Sea.
There are five species of Polychaeta found by Fauvel (1933) in the Gulf of
Suez, but not in the Canal. These are also candidates for an eventual rapid
passage through the Canal as adventives on ships or on other fouling organisms.