Une nouvelle espèce de Pseudoniphargus (Crustacea, Amphipoda, Melitidae) d'une grotte anchialine de la côte méditerranéenne française

A new species of the stygobiont melitid amphipod genus Pseudoniphargus Chevreux, 1901 is described from an anchialine cave located on the inner shore of the Salses-Leucate coastal lagoon, on the French Mediterranean coast. The new species is distinguished from other members of the genus by the combined display of: 1) gnathopod II not sexually dimorphic, with short carpus; 2) outline of basis of pereopods V-VII sexually dimorphic, with both margins convex and with overhanging posterodistal lobe in male, whereas margins subparallel and posterodistal lobe present but not overhanging in female; 3) uropod I protopod lacking basofacial robust seta; 4) protopod of uropod III sexually dimorphic, proportionaly more elongated in male; 5) exopod of male uropod III not strongly elongated (less than 12 times as long as wide), slightly upcurved and tapering; female exopod similar but shorter (about 8.8 times as long as wide); and 6) telson wider than long, with distal margin shallowly excavated and with two distal robust setae at each side. The relationships of this species are briefly discussed. © Publications Scientifiques du Muséum national d'Histoire naturelle, Paris.This is a contribution to Spanish MEC projects CGL2005-02217/BOS and CGL2006-01365/BOSPeer Reviewe

A new species of Typhlatya (Crustacea: Decapoda: Atyidae) from anchialine caves on the French Mediterranean coast

A new species of the thermophylic Tethyan relict prawn Typhlatya is described from two anchialine caves near Perpignan (southern France). The new species is closely related to a congener known only from a freshwater cave at Castellón (eastern Spain), about 400 km to the south-west, differing apparently only in the size and shape of the rostrum and the armature of the dactylus of the fifth pereiopod. Based on palaeogeographical evidence and assuming a sister-group relationship between both species, we suggest that their common ancestor could not be older than early Pliocene in age, and that it was already a stygobiont taxon adapted to live in shallow-water marine crevicular habitats. This ancestor would have vanished from the western Mediterranean after the cooling associated with the onset of northern Hemisphere glaciation, about 3 Mya, as documented for other Mediterranean marine taxa. Indeed, the genus is completely stygobiont and does not occur in fluvial environments. The Pyrenees represent a watershed boundary that eliminates the possibility of the derivation of one species from the other by active dispersal after establishment in continental waters. © 2005 The Linnean Society of London.This is a contribution to Spanish MCYT project REN2001-0580/GLO (Anquifauna) and EC Fifth Framework Programme project EVK2-CT-2001–00121 (Pascalis)Peer Reviewe

Englacement, eustatisme et réajustements karstiques de la bordure sud de l'archipel de Madré de Dios (Patagonie, Province Ultima Esperanza, Chili)

Glaciation, eustatics and karst readjustment at the southern edge of the Madre de Dios archipelago (Patagonia, Ultima Esperanza Province, Chile) In the canals of Patagonia (Chile), at a latitude of 50° S, lies the Madre de Dios archipelago, a group of islands with limestone zones that are the most southerly on the planet. Over the course of three expeditions in 2000, 2006 and 2008, alpine caves, marine caves and spectacular lapiaz were explored and found to show karst features in a mountain and fiord environment. Precipitation of 8000 mm/yr and strong winds form exaggerated superficial karst forms. Above all the legacy of the quaternary glaciers (dynamics of glacier retreat, eustatic variation in sea level, isostatic rebound), is the subject of this article. At the confluence of the influences of the Andes mountains to the east and the Pacific ocean to the west, the karst, with its surface, subterranean and sub-marine forms, constitutes a key to the understanding of the landscape. We show that in each stage in this evolution (glacial retreat, sea level rise, isostatic rebound), the karst has developed forms that register 21,000 years of morphology in this unique region.Dans les canaux de Patagonie (Chili), par 50° de latitude sud, l'archipel de Madre de Dios est un ensemble d'îles présentant des zones calcaires qui concentrent les cavités les plus australes de la planète. Au cours de trois expéditions en 2000, 2006 et 2008, gouffres alpins, grottes marines et lapiaz spectaculaires ont été reconnus et constituent les manifestations du karst dans un paysage de montagnes et de fjords. Les précipitations actuelles (8000 mm/an), et les vents violents façonnent des formes karstiques superficielles très exacerbées. C'est plutôt les héritages glaciaires quaternaires (dynamique du retrait glaciaire, variation eustatique du niveau marin et rebond isostatique) qui sont étudiés dans cet article. A la croisée des influences andines (à l'est) et pacifique (à l'ouest), le karst, par ses formes de surface, souterraines et sous-marines constitue une clef dans la compréhension de l'évolution du paysage. On montre ainsi qu'à chaque étape de cette évolution (retrait glaciaire, remontée du niveau marin, rebond isostatique), le karst développe des formes qui enregistrent depuis 21 000 ans la morphogenèse de cet espace insulaire.Glaciares, eustatismo y reajustes kársticos del reborde sur del archipiélago de Madre de Dios (Patagonia, Provincia de Última Esperanza, Chile) En los canales de Patagonia (Chile), a 50° de latitud sur, el archipiélago de Madre de Dios es un conjunto de islas que presentan zonas calcareas que concentran las cavidades más australes del planeta. Durante tres expediciones en 2000, 2006 y 2008, se exploraron simas alpinas, cavidades marinas y lapiaces espectaculares que constituyen las manifestaciones del karst en un paisaje de montañas y fiordos. Las precipitaciones actuales (8000 mm/año) y los vientos violentos modelan formas kársticas superficiales exageradas. En este artículo se estudian los rastros glaciales del cuaternario (dinámica de la retirada glacial, variación eustática del nivel marino y reflotamiento isostático). En medio de las influencias andinas (al este) y del pacífico (al oeste), este karst, en sus formas superficiales, subterráneas y submarinas constituye una de las claves en el entendimiento de la evolución del paisaje. De este modo se pone de manifiesto que en cada etapa de esta evolución (retirada glacial, subida del nivel del mar, rebote isostático), el karst desarrolla formas que registran desde hace 21.000 años la morfogénesis de este espacio insular.Jaillet Stéphane, Maire Richard, Bréhier Franck, Despain Joël, Lans Benjamin, Morel L., Pernette Jean-François, Ployon Estelle, Tourte Bernard. Englacement, eustatisme et réajustements karstiques de la bordure sud de l'archipel de Madré de Dios (Patagonie, Province Ultima Esperanza, Chili). In: Karstologia : revue de karstologie et de spéléologie physique, n°51, 1er semestre 2008. Englacement et karstification en Patagonie chilienne. pp. 1-24