History of the Population of the Canal
73
Lake Timsah and mentions that many Penaeus sp. were fished in Lake Timsah.
Holthuis (1956) identifies this species as Metapenaeus stebbingi. Krukenberg mentions the first capture (in Lake Timsah) of one specimen of Portunus pelagicus. He
also supposes that Keller's "kleine Krabbe" from Timsah was probably Pilumnopeus vauquelini, an identification accepted by Holthuis (1956).
From all that can be reconstructed from Fischer's, Keller's, and Krukenberg's
information during the period 1870-1890, most of the Suez Canal was inhabited
by a hyperhaline-estuarine fauna (see Por, 1973 c), forming everywhere huge biomasses. The metahaline fauna of the Red Sea was still mostly limited to the
southernmost section ofthe Canal.
A change in the biota of the S uez Canal occurred in the last decade of the 19th
century. The maximum salinity decreased to below 60%0 even in the deeper levels
of the Bitter Lakes. The significance of this fact was that the metahaline marine
species of the Red Sea could settle in the Great Bitter Lake and thereafter extend
their range over the whole ofthe Canal.
From that point onward the predominance of the Red Sea species in the Canal
became established and the way for the colonization of the Eastern Mediterranean lay open.
This new situation was exemplified by the advance of the swimming crab
Portunus pelagicus through the Canal (Fox, 1924, 1926; W. Steinitz, 1929). In 1889
the crab was still mainly confined to the southern segment of the Canal. In 1893 it
was caught in great numbers in the Bitter Lakes and in 1898 it had reached Port
Said. By 1902 it was commonly caught at Port Said.
Unfortunately, for the whole period extending from Krukenberg's collecting
in 1886 till the Cambridge Expedition in 1924, no general collecting was done in
the Canal. There is the very thorough study of fish by Tillier (1902), and for
molluscs the similarly good works of Bavay (1898), and Tillier and Bavay (1905).
However both authors spent several years in the Canal area and the years of the
publication of their studies indicate the latest date for the faunal picture they
present. There are however, no dates or seasons in which the different species were
collected or seen by these authors. In 1902 a collection of Copepods were sampled
through the pump of a throughgoing ship by Professor Herdman (see Thompson
and Scott, 1903; Por and Marcus, 1972).
As far as we can judge, by the turn of the century the Canal was already
inhabited by the same fauna as today. The fact that the Bitter Lakes (and probably also Lake Timsah) have gone through rapid successional stages until reaching
a climax lasting from the beginning of this century, has been pointed out by Por
(1973c). Ben-Tuvia (1975b) collected in the Great Bitter Lake in 1973 only species
offish which had been already reported by Tillier (1902) 70 years ago. Comparing
all the known data on molluscs, Barash and Danin (1972) did not find any radical
change since the fairly exhaustive list ofTillier and Bavay (1905).
Regarding the other animal groups one has to rely on the results published
after the Cambridge Expedition in 1924, the Gruvel Expedition in the early
thirties, the field notes of 1944-1945 by Tortonese-(1952) and data collected by
Beets in 1950 (Beets, 1953; Holthuis, 1956). If one compares the results of the
Hebrew University-Smithsonian Institution collecting in the Suez Canal between
1967-1972 (por and Ferber, 1972; Por et al., 1972 and others) it is evident that the
73
Lake Timsah and mentions that many Penaeus sp. were fished in Lake Timsah.
Holthuis (1956) identifies this species as Metapenaeus stebbingi. Krukenberg mentions the first capture (in Lake Timsah) of one specimen of Portunus pelagicus. He
also supposes that Keller's "kleine Krabbe" from Timsah was probably Pilumnopeus vauquelini, an identification accepted by Holthuis (1956).
From all that can be reconstructed from Fischer's, Keller's, and Krukenberg's
information during the period 1870-1890, most of the Suez Canal was inhabited
by a hyperhaline-estuarine fauna (see Por, 1973 c), forming everywhere huge biomasses. The metahaline fauna of the Red Sea was still mostly limited to the
southernmost section ofthe Canal.
A change in the biota of the S uez Canal occurred in the last decade of the 19th
century. The maximum salinity decreased to below 60%0 even in the deeper levels
of the Bitter Lakes. The significance of this fact was that the metahaline marine
species of the Red Sea could settle in the Great Bitter Lake and thereafter extend
their range over the whole ofthe Canal.
From that point onward the predominance of the Red Sea species in the Canal
became established and the way for the colonization of the Eastern Mediterranean lay open.
This new situation was exemplified by the advance of the swimming crab
Portunus pelagicus through the Canal (Fox, 1924, 1926; W. Steinitz, 1929). In 1889
the crab was still mainly confined to the southern segment of the Canal. In 1893 it
was caught in great numbers in the Bitter Lakes and in 1898 it had reached Port
Said. By 1902 it was commonly caught at Port Said.
Unfortunately, for the whole period extending from Krukenberg's collecting
in 1886 till the Cambridge Expedition in 1924, no general collecting was done in
the Canal. There is the very thorough study of fish by Tillier (1902), and for
molluscs the similarly good works of Bavay (1898), and Tillier and Bavay (1905).
However both authors spent several years in the Canal area and the years of the
publication of their studies indicate the latest date for the faunal picture they
present. There are however, no dates or seasons in which the different species were
collected or seen by these authors. In 1902 a collection of Copepods were sampled
through the pump of a throughgoing ship by Professor Herdman (see Thompson
and Scott, 1903; Por and Marcus, 1972).
As far as we can judge, by the turn of the century the Canal was already
inhabited by the same fauna as today. The fact that the Bitter Lakes (and probably also Lake Timsah) have gone through rapid successional stages until reaching
a climax lasting from the beginning of this century, has been pointed out by Por
(1973c). Ben-Tuvia (1975b) collected in the Great Bitter Lake in 1973 only species
offish which had been already reported by Tillier (1902) 70 years ago. Comparing
all the known data on molluscs, Barash and Danin (1972) did not find any radical
change since the fairly exhaustive list ofTillier and Bavay (1905).
Regarding the other animal groups one has to rely on the results published
after the Cambridge Expedition in 1924, the Gruvel Expedition in the early
thirties, the field notes of 1944-1945 by Tortonese-(1952) and data collected by
Beets in 1950 (Beets, 1953; Holthuis, 1956). If one compares the results of the
Hebrew University-Smithsonian Institution collecting in the Suez Canal between
1967-1972 (por and Ferber, 1972; Por et al., 1972 and others) it is evident that the