The major reef-building coral genus Acropora has never been recorded, living or fossil, from the Marquesas Islands in the central Pacific Ocean, which are characterized by limited modern reef formations. During the "Musorstom 9" cruise in 1997, investigations of marine platforms representing drowned reef systems revealed for the first time the presence of two Acropora species as fossils at seven Marquesas islands. The predominant species was Acropora valida, which was widespread in the archipelago and dated between 7.4 and 48.6 ka, providing evidence of an earlier Pacific distribution pattern broader than previously observed. It is proposed that disappearance of Acropora after 7.4 ka was linked to climatic events probably ENSO events controlling the distribution of corals and coral reefs in the eastern Pacific without excluding alternatively the effects of an increase in sea-level rise.

MUSORSTOM 9

CORINDON 2, ???msg.security.private???, KARUBAR, MUSORSTOM 1, MUSORSTOM 2, MUSORSTOM 3

Six species were studied inhabiting tubes associated with antipatharians. One genus and four species are new to science and are described: Aciculomarphysa cornes geo. Et sp. n., Neohololepidella antipathicola sp. n., Eunice marianae sp. n. and Eunice kristiani sp. n.

BENTHEDI, MD32 (REUNION), MUSORSTOM 6, VOLSMAR

Leptohelia flexibilis gen. nov. et sp. nov., the first stylasterid with a combined calcified and non-calcified skeleton, is described from seamounts and the slope off the islands of New Caledonia, in the southwestern Pacific. The new species is distinguished from all other species of the family Stylasteridae by having a non-calcified organic axis, internal to the basal portion of the calcified corallum. The internal axis is flexible and enclosed by a series of up to 10 calcified annuli, allowing passive lateral bending of the colony. Molecular phylogenetic analyses confirm that Leptohelia flexibilis is a stylasterid coral and reveal that the species is closely related to Leptohelia microstylus comb. nov., a southwestern Pacific stylasterid that lacks an internal axis.

BIOCAL, LAGON, MUSORSTOM 4, MUSORSTOM 5, MUSORSTOM 6, NORFOLK 2, SMIB 2

During the CALSUB cruise, bathyal environments were explored off the New Caledonia corallian platfdrms (southwestern Pacific). Green algae were observed down to a depth of 1 IO m, and red algae down to 145 m. Algal blocks, pebbles and sands contribute to sedimentation to a depth of 400 m and beyond, and are mixed with autochthonous fossils and bioclasts produced by bathyal benthos. Epibathyal fauna suggests similarities with Jurassic and Cretaceous fauna of Tethyan margins (Nautilus, pleurotomarian gastropods, sponges, brachiopods and crinoids…). Richness and abundance of the benthos are the highest in areas where currents are frequent between 300 m and 700 m (sometimes 10 to 20 terebratulid brachiopods per m2 or dense populations of echinoderms entirely covering the substrate). Such currents induce erosion of' substrate or bioclastic accumulations. Biocorrosion seems to be very active in erosion processes, especially on hard grounds. Burrows and traces show the importance of sediment bioturbation on slopes. The occurrence on bathyal slope of some taphonomic processes previously known from geological series and generally considered as closely related lo shallow-water environments should be emphasized.

CALSUB

L'exploration de la faune profonde de NouvelleCalédonie a débuté par des campagnes d'essai de 1977 à 1979 sur des fonds de 200 m à 1000 m au large de la Grande Terre, de l'île des Pins et des îles Loyauté (Intès, 1978). A partir de 1985, elle s'est élargie et intensifiée avec les campagnes MUSORSTOM 4 à 6 et CHALCAL (Richer de Forges, 1990), BIOCAL, BIOGEOCAL et SMIB, complétées par des observations directes à l'aide de la soucoupe plongeante Cyana lors de la campagne CALSUB. Nous ne donnerons ici que les grands traits de l'étagement de la macrofaune et de la mégafaune benthique en insistant sur les observations directes insitu lors de la campagne CALSUB et sur la liaison avec les caractères du milieu.

CALSUB

BIOCAL

Sphinctozoan sponges were major reef-builders in the Permo-Triassic. For a long time, they were considered to be extinct, until a discrete, solitary "living fossil" was found in cryptic reef habitats. A new extant sphinctozoan, with the same colonial morphology and construction capabilities as its fossil counterparts, has been discovered in bathyal environments off from New Caledonia. A significant difference from modern scleractinian reff-builders is the particularly low growth rate: the basal part of a 10 cm thick contruction is approximately 700 years old.

CALSUB

Vitreotubus digeronimoi n.g., n.sp. (Polychaeta Serpulidae) Crom the Lower Pleistocene of Sicily and the bathyal zone of the Azores and the Indian Ocean. The new species, type of a new genus, is described in detail after Recent material from the Atlantic, and accessorily, from the Indiao Ocean. Its vitreous tube of a very particular shape has been found fossil in the Mediterranean basin. The species which no longer lives in the Mediterranean, may be used as a paleoecological indicator.

BENTHEDI, ???msg.security.private???

CALYPSO 1961-62

CALYPSO 1961-62

Scléractiniaires d'eau profonde du sud-ouest de l'océan Indien comportant des loges creusées par des crabes, probablement Hapalocarcinidae. Depuis le 19e siècle on connaît des Hapalocarcinidae associés aux coraux récifaux (coraux "hermatypiques"). Ce n'est que récemment qu'on en a trouvé sur des Scléractiniaires dépourvus de Zooxanthelles. Ces coraux ne font pas partie de la faune récifale et vivent dans des eaux comparativement plus profondes (trois espèces ouest africaines, profondeur environ 50-100 m). Des loges typiques de crabes, creusées probablement par des Hapalocarcinidae, viennent d'être découvertes dans des coraux de profondeurs encore plus grandes: sur une espèce du genre solitaire Trochocyathus (Caryophylliidae) du Natal (165 m) et sur une espèce du genre colonial Enallopsammia (Dendrophylliidae) des Comores (475-530 m) et du sud de Madagascar (620-635 m). Dans les deux espèces hôtes les loges sont creusées par un processus chimique dans le squelette et entourées de dépôts ou d'excroissances anormales à la suite d'une reaction du Scléractiniaire contre la pénétration du crabe.

BENTHEDI, MD08 (BENTHOS)

A large, geographically diverse selection of scleractinian corals, mostly ahermatypes, has been surveyed for galls caused by endoparasites of the ascothoracid family Petrarcidae, which till now have only been known from very few examples. Approximately 30 species of coral in 3 suborders, comprising about 70 distinct populations worldwide (concentrated in the Indo-West Pacific) , from the surface to 5 870 m, bear such galls. Most galls occur within calices (internal galls), but some colonial corals bear galls on their surface independent of calices (external galls); both kinds have a spongy texture that often involves substantial alterations of the host skeleton. Photographs of many infested corals are included. The apparent process of development of both types of gall is described. Parasites themselves were found in about one third of the infested populations and were referable to at least 8 species in 3 genera of Petrarcidae; most of these have been described elsewhere, but a few new records are given here. Preliminary remarks on host-parasite specificity are given.

???msg.security.private???, BENTHEDI, ???msg.security.private???, MD28 (SAFARI II), MD32 (REUNION), MUSORSTOM 2, ???msg.security.private???, ???msg.security.private???