SYSTEMATIQUE ET ECOLOGIE D'ANNELIDES POLYCHETES DE LA PRESQU'IL DU SINAI

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ABSTRACT

This paper summarizes taxonomic and biocenotic investigations on Polychaeta carried out in the Gulf of Elat (= Gulf of 'Aqaba) and Gulf of Suez from 1968 to 1973. The material described was gathered by (1) L. Fishelson and coworkers on numerous expeditions around the littoral of Sinai Peninsula, (2) Ch. Lewinsohn by dredging from a trawler in the Gulf of Elat, and (3) Y. Dafni and M. Goren as part of their theses. Altogether, data are given for about 250 species of 135 genera and 26 families. Three species are new: Eupomatus dafni, Iphione reticulata, Sphaerodoridium simplex. Twelve species are new records for the Red Sea: Phyllodoce gravida Gravier, Notopygos megalops McIntosh, Chloeia flava (Pallas), Uncopolynoe corallicola Hartmann-Schröder, Pareulepis wyvillei (McIntosh), Harmothoe lunulata (Delle Chiaje), Podarke agilis Ehlers, Eunice harassii Audouin and Milne-Edwards, Hydroides inornatus Pilai, Spirobranchus lima (Grube), Spriobranchus polytrema (Philippi) and Protis arctica (Hansen).

The ecological analysis showed that 28 species were typical for dead corals. Of 14 coral colonies investigated, individuals of Nereis mirabilis were found in 11 colonies, Paleanotus debilis and Opisthosyllis longicirrata in 10 colonies, Nereis coutierei and Polyophthalmus pictus in seven colonies and Phyllodoce madeirensis and Opisthosyllis laevis in three colonies. As for bathymetric distribution, 22 species were found below 40 m depth. Of these, Eupanthalis kinbergi and Pareulepis wyvillei were collected at a 400–500 m depth, Oenone fulgida and Glycera longipinnis—250–300 m, and Hyalinoecia tubicola, Armandia longicaudata, Spirobranchus lima and Protula tubularia—80–100 m. A rich and characteristic polychaete community was found in polluted near-shore regions, especially near oil terminals in the Gulfs of Elat and Suez. Of 26 species collected there, the most common were Capitello capitata, Syllides fulva, Chloeia fusca, Parasphaerosyllis indica and Microspio mecznikowianus. Fifty species were collected in a relatively new artificial lagoon near the town of Elat, most of them from fouling on floating buoys. Several of these were found only in this particular habitat, e.g., Harmothoe gilchristi, Hololepidella nigropunctata, Iphione reticulata, Nereis costae, Nereis pachychaeta. Among Polychaeta collected on other animals, Scalisetosus longicirrus occurred on about 12 crinoid species distributed from the shallow subtidal to a depth of 40 m. Two species were collected on Fungia corals: Malmgrenia castanea on F. fungites; Harmothoe lunulata ssp. synaptae on F. scutaria. Several species were collected on sponges, especially on the toxic Latrunculia magnifica: Harmothoe lunulata and Polyeunoa laevis seem the most typical. Filograna implexa, that occurred on sponges, was found also on Octocorallia. Fifteen species were collected on various Octocorallia, especially Gorganaria. Most of these were typical for this type of host, and were not found on other animals.

Summarizing the present biocenotic data together with those published by Fishelson and Rullier in 1969, of 310 polychaete species, 180 were collected from dead coral skeletons, 90 from algal growths, 50 from soft bottoms and 32 from sponges and other hosts. As for the bathymetric distribution, 270 species are found at 0–5 m depth, 115 at 5–20 m, 40 at 20–40 m and only 22 between 40 and 500 m, the deepest point from which material was collected. Zoogeographically, 77 species are common to the Mediterranean and Red Sea, 72 to the Indo-Pacific and Red Sea, and 84 to the Atlantic and Red Sea. So it seems that the northern Red Sea polychaete fauna has an intermediate composition, with almost equal numbers of species common to each of the surrounding water masses.