Zero of Animal Life probably about 300 fathoms

were collected or photographed in the Levant Sea at

depths greater than in the western Mediterranean

(Goren and Galil, 1997, 2002). Several molluscs,

Crenilabium exile, Yoldiella philippiana, Bathyarca

philippiana, Thyasira granulosa, Allogramma for-

mosa, and Cuspidaria rostrata, have been collected

from greater depths in the Levantine Sea than in the

southern Tyrrhenian Sea (Di Geronimo et al., 2001).

Extension of the depth records was also reported for

five of the bathyal amphipods collected off the

Israeli coast, in the case of Bathymedon monoculod-

iformis, for as much as 1100 m (Sorbe and Galil,

2002). The Levantine Sea bathyfaunal scarcity may

cause different parcelling of the populations that is

reflected in bathymetric distributions that differ

from those of the western Mediterranean deep water

assemblages. 

Geographical and environmental factors and the

Levantine deep water fauna 

The Mediterranean Pleistocene bathyal assem-

blages are more closely related to the Atlantic

bathyal than to the present-day Mediterranean deep

water fauna (Barrier et al., 1996). This disparity was

attributed in part to the shallow Gibraltar sill that

bars the deep water of the Atlantic Ocean from enter-

ing the Mediterranean, and the Mediterranean out-

flow that bars the entry of the deep water Atlantic

fauna into the Mediterranean (Salas, 1996). The

onset of the warm homothermy led to the demise of

many cold stenothermic and stenohalinic species and

the eventual impoverishment of the bathybenthos. In

addition, the extreme oligotrophy of the Levantine

Sea prevented settlement by members of the Atlantic

bathyal that have been able to cross the shallow

Gibraltar Straits and the Siculo-Tunisian sill (< 400

m) (Pérès, 1985). The recurring stagnant (dysoxic

and anoxic) Quaternary episodes resulted in a reduc-

tion, or even extinction of deep bottom-living fauna

unable to avoid annihilation by adapting to shallow-

er depth: Van Harten (1987) reported that “Several

species of deep-water ostracodes that are still com-

mon in the Western Mediterranean became extinct in

the Eastern Mediterranean basin at the onset of early

Holocene S1 sapropel deposition”. Bacescu (1985)

believed that the bathyal bottoms of the Levant are

still “unfavourable”, or even “azoic”, after the last

sapropelic event, dated between 9000 and 6000 years

BP, and George and Menzies (1968) suggested “that

sufficient time has not elapsed to allow colonisation

of the deep-sea floor”. 

The bathybenthic amphipods and cumaceans are

indicative because the low mobility of their adults

and their lack of a pelagic larval stage would restrict

their dispersal into the Levantine Sea, effectively

separated from the Atlantic Ocean by the Gibraltar

and Siculo-Tunisian straits. Indeed, the common

amphipods and cumaceans at depths greater than

1000 m off the Israeli coast are all eurybathic

Atlanto-Mediterranean and Boreal species with an

upper bathymetric range enabling them to overcome

that barrier. None of the species with an upper

bathymetric limit set at 400 m (Bellan-Santini,

1990) were collected during the study. This is the

case for the molluscan fauna as well: K. abyssicola,

C. costellata, E. tetragona and B. pectunculoides are

eurybathic species with upper bathymetric range

well within the circalittoral (> 150 m), whereas both

the more stenobathic B. macra and B. tenella have

epipelagic larvae (Bouchet and Warén, 1979),

enabling them to overcome the barrier posed by the

shallow sills. However, 9 of the 12 thecostomate

species collected in the Levantine Sea were record-

ed from cores dating to the upper and middle

Pleistocene taken in the Ionian Sea (Grecchi, 1984)

and, in fact, 12 of the 13 thecostomate species

known from the western Mediterranean (Corselli

and Grecchi, 1990) were collected in the present

study off the coast of Israel. The evidence that the

strictly epipelagic fauna is not impoverished in

terms of species richness underscores the impor-

tance of the sills and/or the Quaternary extinctions

in determining the character of the deep bottom-liv-

ing fauna.

Bouchet and Taviani (1992) suggested that much

of the Mediterranean deep-sea fauna is made-up of

non-reproducing pseudopopulations that have

entered the Mediterranean as meroplankton with the

Atlantic inflow at Gibraltar. However, the popula-

tions of the most common benthic molluscs at

depths greater than 1000 m off the Israeli coast are

composed of both adult and juvenile specimens, and

one species, Yoldia micrometrica, the most common

and abundant species in the Eastern Mediterranean,

is unrecorded from the westernmost part of the sea

(Salas, 1996). Moreover, gravid benthic decapod

crustaceans and fish were collected from the depths

of the Levantine Sea (Galil and Goren, 1994; Goren

and Galil, 1997; Fishelson and Galil, 2001). 

Though much reduced in diversity and richness

compared with the deep sea fauna of the western and

central basins of the Mediterranean, the Levantine

bathybenthos is composed of autochthonous, self-

THE BATHYAL FAUNA OF THE LEVANTINE SEA

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