New species from the deep Pacific suggest that carnivorous sponges date back to the Early Jurassic

Some deep-sea poecilosclerid sponges (Porifera) have developed a carnivorous feeding habit that is very surprising in sponges^1^. As shown by the typical morphology of their spicules, they most probably evolved from "normal sponges" under the difficult conditions of a deep-sea environment. Such evolution, which implies the loss of the diagnostic character of the phylum Porifera, i.e. a filter feeding habit through a complex aquiferous system, should be of great interest in the understanding of the origin of metazoans. Some scenarios, based on the hypothesis of the paraphyly of Porifera, allege that metazoans could derive from a sponge filter-feeding body plan. A difficulty, however, is to imagine the transition from a sponge grade of organization to other organization plans^2^. Carnivorous sponges demonstrate that a functional, non filter-feeding animal may derive from a conventional sponge body plan, albeit nothing is known of the age of this evolution. Here we report that newly discovered species of _Chondrocladia_ from the deep Pacific display special spicules that were previously recorded only as isolated spicules from sediment dating back to the Early Jurassic and Miocene periods. This suggests that the evolution of carnivorous sponges from filter-feeding poecilosclerid demosponges could date back at least from the Early Mesozoic

Sponges (Porifera) In Submarine Caves

Sponges (phylum Porifera) have the most simple and probably the most ancient body plan of the multicellular animals. They are, however, very successful in most benthic ecosystems. They are dominant in submarine caves, where their study has provided unexpected results. Submarine caves share several ecological features with deep-sea habitats. The communities living in these habitats depend on allochthonous organic input, and some bathyal species are able to colonize the darkest parts of littoral caves. Some examples will be given, including calcified sponges,«living fossils» of ancient reef builders. Faunal and environmental similarities, however, are limited by the obvious differences in pressure, temperature, habitat size, and by the dispersal abilities of deep water organisms. A recently discovered Mediterranean cave more closely approximates deep-sea conditions, due to the entrapment of a cold water mass resulting in stable temperature conditions throughout the year. Easily accessible to scuba divers, this «bathyal island» in the littoral zone is a natural mesocosm of the deep Mediterranean which offers exceptional opportunities for deep-sea biology. Preliminary results have already provided unexpected insights, which are illustrated. A large population of Oopsacas minuta, a representative of the bathyo-abyssal hexactinellid sponges, reproduces here year round - making possible the first observations of larval behaviour and ultrastructure to be carried out on this phylogenetically important group of invertebrates, and opening up the poorly known area of larval ecology of these deep-sea sponges. The presence of a species of the deepest known genus of sponges, Asbestopluma (8 840 m in the Central Pacific) is a fascinating opportunity to investigate the biology of the strange deep-sea cladorhizid sponges, which may live in the most oligotrophic abyssal basins. A highly unexpected result is that they are non-filter-feeding sponges with a carnivorous feeding habit. They capture and digest small crustaceans by means of filaments provided with minute hook-shaped spicules. The biology and peculiarities of this carnivorous sponge are illustrated by a video

Esponjas lithistidas de cuevas submarinas en el Mediterráneo: su taxonomía y relaciones

Several lithistid sponges are described from Mediterranean caves occurring in the northwestern and Adriatic basins. In the Corallistidae, Neoschrammeniella bowerbanki and Neophrissospongia nolitangere are recorded for the first time from the Mediterranean, whereas Neophrissospongia radjae n. sp. and Neophrissospongia endoumensis n. sp. are described as new. In the Theonellidae, the common sponge previously identified as Discodermia polydiscus is described as Discodermia polymorpha n. sp. Fossil specimens from the 3PP cave are tentatively attributed to Neoschrammeniella bowerbanki. The distribution and affinities of this lithistid fauna are discussed.Se describen varias esponjas lithistidas procedentes de cuevas del noroeste del mar Mediterráneo y de las cuencas del mar Adriático. Dentro de las esponjas incluidas en la familia Corallistidae, Neoschrammeniella bowerbanki y Neophrissospongia nolitangere, se registran por primera vez en el Mediterráneo y Neophrissospongia radjae n. sp. y Neophrissospongia endoumensis n. sp. se describen como nuevas especies. Dentro de la Familia Theonellidae, la esponja común, que hasta la fecha se había identificado como Discodermia polydiscus se describe como Discodermia polymorpha n. sp. Ejemplares fósiles de la cueva de los 3PP se asignan provisionalmente a Neoschrammeniella bowerbanki. Se discute la distribución y afinidades de la fauna de las lithistidas

A giant foraminifer that converges to the feeding strategy of carnivorous sponges: Spiculosiphon oceana sp. nov. (Foraminifera, Astrorhizida)

14 páginas, 6 figurasThe foraminifer Spiculosiphon oceana sp. nov. is a giant (>4 cm) agglutinated astrorhizid, which makes the second known species of this unusual genus and its first Mediterranean record. It has a peculiar stalked, capitate, monothalamous test. Bleach digestion and X-ray microanalysis indicated the test to be made exclusively of siliceous sponge spicules agglutinated in organic cement. The organism stands on a hollow, 4 cm long, 0.5 cm thick stalk built with highly selected, long and thin spicule fragments, tightly cemented together in parallel to the main axis of the stalk. The proximal end of the stalk is closed and slightly expanded into a bulb-like structure, designed to penetrate between the sand grains and maintaining the test upright while avoiding a permanent attachment to the substratum. The distal stalk end becomes a hollow, globelike structure that contains the main protoplasm. The globelike region is built with loosely agglutinated and irregularlyshaped spicules, allowing extrusion of the pseudopodia through the cavities between the spicules. The globelike structure also serves as an anchoring basis, from which long and thin, solid tracts protrude radially to make a spherical crown that attains about 4 mm in total diameter. The radiating tracts are built with highly selected aciculate spicule fragments held together with a translucent organic cement. They provide skeletal support for the extension of a crown of pseudopodia into the water column. This arrangement is thought to enhance the chances of the pseudopodia to contact demersal planktonic prey. In summary, Spiculosiphon species collect and arrange sponge spicules with high selectivity to recreate a body morphology that strongly converges to that of some carnivorous sponges, which allows these predatory foraminifera to exploit a prey capturing strategy similar to that of the carnivorous sponges. This idea is also consistent with our report of an additional, yet undetermined, Spiculosiphon species occurring in the same sublittoral Mediterranean cave where carnivorous sponges were first discovered.This research has benefited from funds of the Spanish Ministry of Economy and Competitiveness grant (CTM2012-37787) to MM.Peer reviewe

A Reminiscence of the Nicaraguan Filibusters.

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Development of MKIDs in the Optical and Near-infrared Bands for SPIAKID

SpectroPhotometric Imaging in Astronomy with Kinetic Inductance Detectors (SPIAKID) aims at designing, building, and deploying on the sky a spectrophotometric imager based on microwave kinetic inductance detectors (MKIDs) in the optical and near-infrared bands. MKIDs show a fast response and the ability to resolve photon energy compared to the conventional Charge-coupled Devices (CCDs). In this paper, we present the design and simulation of the MKID arrays for SPIAKID. The detectors consist of four arrays with each array of 20,000 lumped-element pixels, and each array will be read with 10 readout lines. %The array is designed to have resonances between 4-8GHz with a frequency spacing of 2 MHz and a coupling quality factor (Qc) of about 50000. The meander material of the resonators is trilayer TiN/Ti/TiN to have better uniformity of the critical temperature across the array. We also present the measurement result for a test array with $30\times30$ pixels which is a subset of the designed 2000-pixel array to verify the design and fabrication. The current measured best energy resolving power $R = E/\Delta E$ is 2.4 at $\lambda = 405~$nm and the current medium R is around 1.7. We have also observed the response of the TiN/Ti/TiN is much smaller than expected.Comment: 9 pages, 6 figures. Accepted by the Journal of Low Temperature Physic

Séance spécialisée : géodynamique des bassins océaniques et des marges continentales

Une morphologie de fonds sous-marins bathyaux comportant des indurations liées à des dépôts ferro-manganésifères inclus dans des sédiments hémipélagiques peu ou pas cimentés a été découverte sur une ride volcanique tertiaire au large de la Nouvelle-Calédonie (SW Pacifique). Elle semble être en relation avec des circulations hydrothermales au travers de la couverture sédimentaire pendant l'activité volcanique miocène de la ride des Loyauté. (Résumé d'auteur

Action plan for the conservation of habitats and species associated with seamounts, underwater caves and canyons, aphotic hard beds and chemo-synthetic phenomena in the Mediterranean Sea (Dark Habitats action plan)

Dark habitats are environments where the luminosity is extremely weak, or even absent (aphotic area) leading to an absence of macroscopic autochthonous photosynthesis. The bathymetric extension of this lightless area depends to a great extent on the turbidity of the water and corresponds to benthic and pelagic habitats starting from the deep circa-littoral. Caves which show environmental conditions that favour the installation on of organisms characteristic of dark habitats, are also taken into account. Dark habitats are dependent on very diverse geomorphological structures (e.g. underwater caves, canyons, slopes, isolated rocks, abyssal plains, cold seeps, brine anoxic lakes, hydrothermal springs and seamounts). Dark habitats represent outstanding and potential ecosystems with regard to their: Frailty and vulnerability to any land-based pressure Play an important part in the way the Mediterranean ecosystem functions, insofar as they constitute the main route for transferring matter between the coast and the deep sea Considered as biodiversity hotspots and recruiting areas forming a veritable reservoirs of knowledge and biodiversity Natural habitats that come under Habitat Directive on the conservation of natural habitats and of wild fauna and flora and appear as such as priority habitats requiring protection (Directive 92/43). A certain number of underwater caves enjoy protection status because they fall within the geographical boundaries of Marine Protected Areas (MPAs) Understanding of these functions is necessary for a better understanding and management of the biodiversity of Mediterranean coastal zones and continental shelf.peer-reviewe

Signification géodynamique des calcaires de plate-forme en cours de subduction sous l'arc des Nouvelles-Hébrides (Sud-Ouest de l'océan Pacifique)

Note présentée par Jean DercourtInternational audienceThe analysis of carbonates from New Hébrides Trench shows that three main épisodes of shallow water carbonate déposition occurred during Late Eocene,Late Oligocene-Early Miocène,Mio-Pliocene-Quaternary, controlled by eustatism and tectonic.L'analyse de carbonates issus de la fosse des Nouvelles-Hébrides a permis de reconnaître trois périodes favorables au développement de plates-formes(Éocène supérieur,Oligocène supérieur-Miocène inférieur,Mio-Pliocène-Quaternaire)contrôlé par l'eustatisme et la tectonique