Suchergebnisse

Au-delà de 40° S, l'Expédition antarctique belge a capturé une espèce de Doliolodae : Doliolona resistibile, et une espèce de Salpidae : Salpa thompsoni. Entre 34° S et 40° S, les prises ont intéressé 4 espèces de Doliolidae : Doliolum denticulatum, D. nationalis, Dolioletta (gegenbauri ?) et une forme rare de profondeur, Doliopsoides meteori, et 3 espèces de Salpes : Brooksia rostrata, Thalia democratica et Thalia longicauda. Aucun Pyrosome n'a été récolté. Le long de la côte orientale de l'Afrique ont été rencontrées 5 espèces de Doliolidae : Doliolina mulleri krohni (?), Doliolina indicum, Doliolum denticulatum, Doliolum nationalis et Dolioletta gegenbauri tritonis, plusieurs espèces de Pyrosomidae telles que Pyrosoma agassizi, Pyrosoma spinosum, Pyrosoma verticillatum et des colonies immatures (de P. atlanticum ?), 16 espèces et sous-espèces de Salpidae : Cyclosalpa pinnata sewelli, Cyclosalpa virgula, Brooksia rostrata, Ihlea punctata (première mention), Salpa maxima, Salpa cylindrica, Salpa fusiformis, Salpa aspera, Ritteriella amboinensis, Ritteriella picteti, Metcalfina hexagona, Iasis zonaria, Thalia democratica, Thalia orientalis, Thalia cicar, Thalia rhomboides. Seules Tethys vagina et Pegea confoederata n'ont pas été retrouvées. La distribution de ces diverses espèces dans l'océan Indien a été présentée.

The species collected by the two expeditions have all previously been reported from the area. A few rare species know from the area have been obtained by the two expeditions, e.g., Ritteriella amboinensis (Apstein, 1904) and Traustedtia multitentaculata (Quoy & Gaimard, 1835), the latter occuring in the open sea from a depth of a few hundred meters to the surface. Doliolum denticulatum, Dolioletta gegenbauri tritonis, Thalia democratica, and Salpa cylindrica are the only well represented species in the collections. The other species are either scarce or occur at a few stations. The following species occur: a) True tropica (stenotherm) species: Pyrosoma aherniosum, Cyclosalpa floridana, Brooksia rostrata, Salpa cylindrica, Thalia cicar. b) Slightly more eurytherm species, reaching somwhat higher latitudes(altough remaining in warm waters): Doliolum denticulatum, Pyrosoma atlanticum, Cyclosalpa polae, Ritteriella retracta, Salpa maxima, Iasis zonaria, Thalia orientalis, Thetys vagina. c) Eurytherm species, tolerating lower temperatures and maybe reaching high latitudes, at least during summer (cosmopolitan oceanic or Lusitanian species): Doliolina mülleri, Dolioletta gegenbauri tritonis, Cyclosalpa bakeri, Ihlea asymmetrica, Salpa fusiformis, Thalia democratica (FRASER 1961, v. SOEST 1975b). Salpa aspera, with origin in the southern hemisphere, is able to spread widely up into the three main oceans. A single cold water form, occuring as nurses caught in deep water, was tentatively identified as Doliolina intermedium. ; Les différentes espèces récoltées par les 2 expéditions sont toutes des espèces capturées par les expéditions précédentes qui explorèrent la région. Manquent quelques espèces rares, e.g., Ritteriella amboinensis (Apstein, 1904) et Traustedtia multitentaculata (Quoy & Gaimard, 1835), une Salpe observée en haute mer et qui a été récoltée de la surface à quelques centaines de mètres de profondeur. Doliolum denticulatum, Dolioletta gegenbauri tritonis, Thalia democratica et Salpa cylindrica sont les seules espèces bien représentées dans les collections; les autres espèces ne se rencontrent qu'en petit nombre ou en un nombre réduit de stations. Les populations de Thaliacés rencontrées par les 2 expéditions confirment le caractère mélangé des eaux de l'Océan Atlantique tropical. Sont présentes : a) des espèces purement tropicales (sténothermes) : Pyrosoma aherniosum, Cyclosalpa floridana, Brooksia rostrata, Salpa cylindrica, Thalia cicar, b) des espèces un peu plus eurythermes, atteignant des latitudes assez hautes (quoique demeurant dans des eaux chaudes) : Doliolum denticulatum, Pyrosoma atlanticum, Cyclosalpa polae, Ritteriella retracta, Salpa maxima, Iasis zonaria, Thalia orientalis, Thetys vagina, c) des espèces eurythermes, capables de supporter une température plus basse et d'atteindre de hautes latitudes, au moins durant l'été (espèces océaniques cosmopolites ou lusitaniennes) : Doliolina mülleri, Dolioletta gegenbauri tritonis, Cyclosalpa bakeri, Ihlea asymmetrica, Salpa fusiformis, Thalia democratica (FRASER 1961, v. SOEST 1975b). Salpa aspera, originaire de l'hémisphère austral, s'avance loin dans les Océans atlantique, indien et pacifique. Une série de nourrices ramenées des eaux froides profondes, pourraient appartenir à l'espèce Doliolina intermedium.

The thaliacean fauna of the eastern Mediterranean (U.A.R. sector) includes the Salps Cyclosalpa pinnata polae Sigl, 1912, Thalia democratica (forma typical Forskal, 1775), Thalia orientalis Tokioka, 1937, Salpa fusiformis Cuvier, 1804, and the Doliolids Doliolina muelleri (Krohn, 1852), Doliolina muelleri krohni (Herdman, 1888), Doliolum denticulatum Quoy & Gaimard, 1824, Doliolum nationalis Borgert, 1894, (?) Dolioletta gegenbauri (Uljanim,1884). The fauna of the Red Sea and the Gulf of Suez includes the Salps (?) Cyclosalpa bakeri Ritter, 1905, (?) Cyclosalpa floridana (Apstein, 1894), Brooksia rostrata (Traustedt, 1893), Ritteriella amboinensis (Apstein, 1894), Iasis zonaria (Pallas, 1774), Salpa cylindrical Cuvier, 1804, and several species (according to van Soest, 1973) of the genus Thalia [Thalia cicar van Soest, 1973; Thalia orientalis Tokioka, 1937, and Thalia rhomboids (Quoy & Gaimard, 1824)], and the Doliolids Doliolina sp., Doliolina muelleri krohni (Herdman, 1888), Doliolina indicum (Neumann, 1906), Doliolum denticulatum Quoy & Gaimard, 1824, and Doliolum nationalis Borgert, 1894. This last species is especially abundant in the Gulf of Suez. The two Cyclosalps, Iasis zonaria and Doliolina indicum are newly recorded from the Red Sea. Pyrosoms are lacking in both sectors, maybe owing to an inadequate prospection. The two faunas are very different, having in common only a few species of worldwide occurrence. It seems little probable that exchange of Thaliacea has occurred between the two seas. ; La faune des Thaliacés de la Méditerranée orientale (secteur de la R.A.U.) comprend les Salpes Cyclosalpa pinnata polae Sigl, 1912, Thalia democratica (forme typica Forskal, 1775), Thalia orientalis Tokioka, 1937, Salpa fusiformis Cuvier, 1804, et les Dolioles Doliolina muelleri (Krohn, 1852), Doliolina muelleri krohni (Herdman, 1888), Doliolum denticulatum Quoy & Gaimard, 1824, Doliolum nationalis Borgert, 1894, Dolioletta gegenbauri ? (Uljanim,1884). La faune de la mer Rouge et du golfe de Suez comprend les Salpes Cyclosalpa bakeri ? (Ritter, 1905), Cyclosalpa floridana ? (Apstein, 1894), Brooksia rostrata (Traustedt, 1893), Ritteriella amboinensis (Apstein, 1894), Iasis zonaria (Pallas, 1774), Salpa cylindrical Cuvier, 1804 et plusieurs espèces, selon van Soest (1973), du genre Thalia : Thalia cicar van Soest, 1973, Thalia orientalis Tokioka, 1937, Thalia rhomboids (Quoy & Gaimard, 1824) et les Dolioles Doliolina sp., Doliolina muelleri krohni (Herdman, 1888), Doliolina indicum (Neumann, 1906), Doliolum denticulatum Quoy & Gaimard, 1824 et Doliolum nationalis Borgert, 1894. Cette dernière espèce est particulièrement bien représentée dans le golfe de Suez.Les deux Cyclosalpes, Iasis zonaria and Doliolina indicum sont des espèces nouvelles pour la mer Rouge. Les Pyrosomes manquent pour les deux secteurs, en raison peut-être d'une prospection insuffisante. Les deux faunes sont très différentes, ayant seulement en commun des espèces à large distribution. La possibilité d'un passage de Thaliacés d'une mer à l'autre reste douteuse.

In the sector of the Mediterranean east of the 22nd meridian, five species of Salpidae (Thalia democratica, Salpa fusiformis, Ihlea punctata, Pegea confoederata and Cyclosalpa pinnata polae) and five species of Doliolidae (Doliolum denticulatum, Doliolum nationalis, Doliolina sp., Doliolina intermedium (?) and Dolioletta sp.) were caught during a serie of cruises. At the same time, four species of Salpidae (Thalia democratica, Salpa cylindrica, Brooksia rostrata and Ritteriella amboinensis) and two species of Doliolidae (Doliolina mülleri krohni and Doliolum denticulatum) were recorded in the Gulf of Elat (Gulf of Aqaba). Two further species, Salpa maxima and Dolioletta gegenbauritritonis, previously recorde from this area, were not found again in the last catches. Pyrosomidae are missing in both areas. The two faunas are very differrent, having in common only a few widely distributed species.

The distribution of Thaliacea collected by several oceanographic cruises throughout the occidental sector of the Indian Ocean has been examined. Between the South of the Mozambique Strait on one hand and the Persian Gulf and the Gulf of Aqaba on the other hand, some 25 species have been identified and the behavior of the most numerous ones, analysed. Most of the species have been found at Nosy-Bé, during a year of regular collections. The sharing of the species between the pelagic zone and the neritic one was observed and the annual cycle of some, defined. Doliolum denticulatum – like D. mülleri – is a mainly pelagic species while D. gegenbauri seems more neritic with a secondary and temporary widespreading towards the outer zone. D nationalis, especially in neritic areas, e.g. the Persian Gulf, has been found under the phorozooid stage and therefore undergoes a short cycle of development like their relatives I, the Mediterranean Sea. A few colonies of both Pyrosoma ambulata and P. fixata have been collected between Mozambique and the Gulf of Aden. In the southern area, their presence is recorded for the first time. Among Salps, some were not found, e.g.: Cyclosalpa affinis and C. floridana, Traustedtia multitentaculata and Thetys vagina, although previously caught by the earlier investigators of the Ocean. A few species were rare, e.g.: Ritteriella amboinensis and R. picteti, Salpa maxima, Pegea confoederata, with not many specimens in the catches as a whole. Iasis zonaria and Metcalfina hexagona were found above the great depths and Brooksia rostrata, Thalia democratica and Salpa cylindrica gathered as well in the neritic areas as in the pelagic areas, while Cyclosalpia pinnata is neritic at Nosy-Bé and pelagic but rare in the Arabian Sea. Salpa fusiformis has been caught at Nosy-Bé during austral winter and spring; in the open sea, both Salpa fusiformis and Salpa fusiformis aspera are living together. The thaliacean fauna of the Persian Gulf and the Gulf of Oman was considered for the first time and proved to be less diversified than that in the Gulfs of Suez and Aqaba. Three species of Salpae (Thalia democratica, Salpa cylindrica and Iasis zonaria), four species of Doliolids (D. mülleri, D. denticulatum, D. nationalis and D. gegenbauri) were found in the catches from the Gulf of Oman; Pyrosomes are lacking. Iasis zonaria does not enter the Persian Gulf, Thalia democratica and Doliolum denticulatum are limited to the eastern part while Salpa cylindrica and Doliolum nationalis are observed at the innermost stations. The Gulf of Aden is richer and most of its species have been also observed in the Red Sea; exception to this rule seems, as far as our present knowledge, to be Iasis zonaria, Metcalfina hexagona, the Cyclosalps and Pyrosomes. The need for more systematic investigations in areas mentioned above must be stressed.

A clinal variation related to the temperature is described in Salpa fusiformis (P.G.), the oriental populations being lesser rich in muscular fibres, but looking more homogeneous than the occidental ones. No similar variation was observed in Thalia democratica (P.S.) although a slight decrease of the fibres mean was detectable during the course of the year in both sectors. Thalia orientalis has been caught in several spots of the oriental sector.