ALVARINO: DISTRIBUTION OF SIPHONOPHORES 



covered by the collections, quantitative data are 

 not considered, and only qualitative data are 

 included in the presentation of the results. 



DISTRIBUTION OF 



SIPHONOPHORES IN THE 



EASTERN MEDITERRANEAN 



AND THE RED SEA 



Twenty-one species of siphonophores were 

 observed in the eastern Mediterranean collec- 

 tions, and fifteen species in the Gulf of Elat (Red 

 Sea) collections. 



Eudoxia russelli (eudoxid of Ch. appendicu- 

 lata), Sulculeolaria angusta, and S. chuni are 

 new records for the Mediterranean. 



Chelophyes contorta, Diphyes bojani, D. 

 dispar, Lensia campanella, L. meteori, L. 

 subtilis, Sulculeolaria quadrivalvis, S. tur- 

 gida. Rosacea plicata, and Apolemia uuaria 

 are first records for the eastern Mediterranean. 

 These species have been previously observed in 

 the western Mediterranean. The only previous 

 records of Ch. contorta for the Mediterranean 

 correspond to the Alboran Sea (Alvarino, 1957). 

 Therefore, the presence of the species in the 

 Levant Mediterranean basin could be considered 

 a tracer of Atlantic waters. All the Mediter- 

 ranean species are also found in the Atlantic. 

 Some of the species have permanently established 

 populations in the Mediterranean, while others 

 may be only remains of the Atlantic flow. 



Most of the species previously found in the 

 eastern Mediterranean (Bigelow and Sears, 1937; 

 Lakkis, 1971) were also observed in the collec- 

 tions here analyzed. 



Some species previously found in the western 

 Mediterranean (M. atlantica, L. fowleri, Clau- 

 sophyes ovata, Ceratocymha sagittata, 

 Vogtia pentacantha, V. spinosa, Praya cymbi- 

 formis, Amphicaryon acaule, Anthophysa 

 rosea, Rhizophysa filiformis, Cordagalma 

 cordiformis, Athoribya rosacea, and Nanomia 

 cara) have not been observed in the eastern 

 Mediterranean (Alvariiio, 1971; Lakkis, 1971) 

 (Table 1). 



The most abundant species in both distribu- 

 tional coverage of the surveyed region and in 

 number of species, Ch. appendiculata, D. 

 dispar, Hippopodius hippopus, Bassia bas- 

 sensis were found along the years, and in 



December appeared scattered or absent (Figures 

 1, 2, 6, 8). Eudoxoides spiralis, S. turgida, 

 S. quadrivalvis , and S. angusta followed in 

 decreasing order of abundance in both space 

 covered and number of individuals (Figures 3, 5). 

 These species appeared abundantly off Israel, 

 Lebanon, Syria and around Cyprus. Sulculeolaria 

 angusta and S. turgida were also found in the 

 Cretan region. 



Species with few scattered records are, E. 

 russelli (north of Cyprus), C/i. contorta (off Israel 

 and between Syria and Cyprus), D. bojani, M. 

 kochi, L. campanella, L. multicristata, L. subtilis, 

 S. chuni, A. tetragona, R. plicata, A. uvaria, 

 Agalma elegans, and Physophora hydrostatica 

 (spread along the Levant basin). (Figures 1-8.) 



It is worthy of notice that the maximum density 

 for most of the species of siphonophores appeared 

 at the easternmost part of the Mediterranean 

 Sea, off Israel and around Cyprus, which can be 

 attributed to the high productivity of the region 

 (Lakkis, 1971). 



The species scattered along the eastern Mediter- 

 ranean, not previously observed in this sea, could 

 be considered tracers of Atlantic waters (Oren, 



1971). 



The presence of L. multicristata (a meso- 

 planktonic species) off Tira, Israel, could be an 

 indicator of upwelling. 



It is well established that the fauna of the 

 eastern Mediterranean is an impoverished fauna 

 from that of the western basin. Many species 

 do not reach the Levant Mediterranean basin, 

 and only appear accidentally there, and few be- 

 come established in the area. Por (1971) con- 

 sidered that "The colder areas of the Aegean Sea 

 probably constitute an environment in which the 

 Atlantic fauna is much better represented and 

 better fitted to withstand the competition of the 

 tropic immigrants." 



Siphonophorae fauna of the Red Sea is poorer 

 than that of the Indian Ocean, both in number 

 of species and in the density of the respective 

 populations. The Gulf of Elat may also include 

 fewer species than the main Red Sea basin. The 

 Gulf of Elat collections correspond to the winter 

 months. Some of the species observed in the Gulf 

 of Elat constitute new records for the Red Sea 

 (Ch. appendiculata, E. russelli, and Diphyop- 

 sis mitra). Por (1971) stated that siphonophores 

 and other holoplanktonic groups have not been 

 found in the Suez Canal waters. 



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