Two new species of the genus Munnogonium (Isopoda: Asellota: Paramunnidae) from Argentina

Two new species of paramunnid isopods from Argentina are described: Munnogonium quequensis n. sp. from Buenos Aires Province (Quequén) and M. diplonychia n. sp. from Patagonia (Comodoro Rivadavia, Rada Tilly and Puerto Deseado). Both species are distinguished from their congeners by having a tight tuft of setae on the frontal margin. These setae have been discovered after examining the specimens under scanning electron microscope; under dissecting microscope they look like a short blunt median projection. M. diplonychia n. sp. differs from M. quequensis n. sp. by having bifid claws on pereopods II–IV. Eighty of the 92 specimens of M. quequensis n. sp. examined were found attached to the sea star Astropecten brasiliensis, a fact that suggests an association between these two species.Fil: Doti, Brenda Lía. Universidad de Buenos Aires. Facultad de Cs.exactas y Naturales. Departamento de Biodiversidad y Biologia Experimental. Laboratorio de Invertebrados Ii; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biologia Experimental y Aplicada; ArgentinaFil: Roccatagliata, Daniel Carlos. Universidad de Buenos Aires. Facultad de Cs.exactas y Naturales. Departamento de Biodiversidad y Biologia Experimental. Laboratorio de Invertebrados Ii; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biologia Experimental y Aplicada; Argentin

On two South-West Atlantic Diastylis (Cumacea: Crustacea), D. obliquisulcata n. sp. and D. geocostae, with remarks on this speciose genus.

A new species, Diastylis obliquisulcata from eastern Patagonia, is fully described and illustrated based on specimens collected in shallow waters. Diastylis obliquisulcata shares with 14 other species of this genus an opercular maxilliped 3, a short telson and rudimentary exopods on pereopods 3 and 4 in the females. Diastylis obliquisulcata can be easily distinguished from all these species by the females having an oblique groove or sulcus on each side of the carapace. The taxonomic position of this group of species in the genus Diastylis is discussed. The adult male of Diastylis geocostae is described for the first time, the adult female briefly redescribed, and its distribution, up to now known from the type locality only (Cabo Frio, Rio de Janeiro State), is extended to off Rawson, Argentina. Within this species there are reported ontogenetic changes in the carapace ornamentation, in the chaetotaxy of the telson, and in the length ratio between the telson and the uropod peduncle.Fil: Alberico, Natalia Andrea. Universidad de Buenos Aires. Departamento de Ciencias Exactas; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Ciudad Universitaria; ArgentinaFil: Roccatagliata, Daniel Carlos. Universidad de Buenos Aires. Departamento de Ciencias Exactas; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Ciudad Universitaria; Argentin

Biodiversity of Isopoda and Cumacea (Peracarida, Crustacea) from the Marine Protected Area Namuncurá-Burdwood Bank, South-West Atlantic

Burdwood Bank is a shallow seamount located south of the Malvinas (Falkland) Islands and east of Tierra del Fuego. In 2013, the area down to 200 m depth of this bank was declared the first open-sea (non-coastal) Marine Protected Area (MPA) in Argentina, and named ?Namuncurá? (MPAN-BB). The present study aimed to evaluate the biodiversity of the isopods and cumaceans from the MPAN-BB. The studied material was collected on board the Argentine RV Puerto Deseado during the Campaña Antártica de Verano 2013. Three stations from the MPAN-BB, respectively located in the core, buffer and transition sectors, were sampled. A total of 17,076 specimens were sorted and 70 taxa distributed in 22 families were identified. Thirty-five new records of distribution and eight species most probably new to science are herein reported. Paramunnidae and Diastylidae were the most abundant and diverse families among isopods and cumaceans, respectively. Our records, together with those obtained from the literature, make a total of 55 nominal species so far known from Burdwood Bank. Except for one nominal species, which had been reported from the Puerto Rico Trench and the Argentine Basin, all the remaining species had also been recorded from other localities within the Magellan Region. In contrast, only nine out of the 55 nominal species had also been reported from the Antarctic Peninsula and/or Scotia Arc. This indicates that the isopods and cumaceans from Burdwood Bank are typically Magellanic, and there is little correspondence between this fauna and that from the Antarctic Peninsula and Scotia Arc.Fil: Doti, Brenda Lía. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Chiesa, Ignacio Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Roccatagliata, Daniel Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; Argentin

Revision of the genus Oxyarcturus (Isopoda, Valvifera, Antarcturidae), with a description of a new deep-sea species from Argentina

A new antarcturid isopod, Oxyarcturus holoacanthus sp. nov., is fully described based on seven specimens collected in the Mar del Plata submarine canyon at 2950 m depth, during the “Talud Continental III” expedition on board the Argentinian RV “Puerto Deseado”. Oxyarcturus holoacanthus sp. nov. is closely related to O. spinosus (Beddard, 1886), from which it can be distinguished by the body spine pattern. The penial plate, a novel character for the genus Oxyarcturus, as well as for the family Antarcturidae, is described in detail. The species O. dubius (Kussakin, 1967) and O. beliaevi (Kussakin, 1967) are considered as incertae sedis until further morphological and molecular data can clarify their taxonomic position. An update of the geographic and bathymetric records of the genus Oxyarcturus is provided

Feedback by massive stars and the emergence of superbubbles. II. X-ray properties

This article has an erratum M. Krause, et al., “Feedback by massive stars and the emergence of superbubbles. II. X-ray properties”, Astronomy & Astrophysics, Vol. 566, June 2014. This version of record is available online at: https://www.aanda.org/articles/aa/abs/2014/06/aa23871-14/aa23871-14.html Reproduced with Permission from Astronomy and Astrophysics, © ESO 2014.Context. In a previous paper we investigated the energy transfer of massive stars to the interstellar medium (ISM) as a function of time and the geometrical configuration of three massive stars via 3D-mesh-refining hydrodynamics simulations, following the complete evolution of the massive stars and their supernovaewith the exception of non-thermal processes. Aims. To compare our results against observations we derivethermalX-ray properties of the ISM from our simulations and compare them to observations of superbubbles in general, to the well-studied nearby Orion-Eridanus superbubble and to the diffuse soft X-ray emission of nearby galaxies. Methods. We analysed our ISM simulation results with the help of spectra for plasma temperatures between 0.1 and 10 keV and computed the spectral evolution and the spatio-temporal distribution of the hot gas. Results. Despite significant input of high-temperature gas from supernovae and fast stellar winds, the resultingthermalX-ray spectra are generally very soft, with most of the emission well below 1 keV. We show that this is due to mixing triggered by resolved hydrodynamic instabilities. Supernovae enhance the X-ray luminosity of a superbubble by 1–2 orders of magnitude for a time span of about 0.1 Myr; which is longer if a supernova occurs in a larger superbubble and shorter in higher energy bands. Peak superbubble luminosities of the order of 1036 erg s-1 are reproduced well. The strong decay of the X-ray luminosity is due to bubble expansion, hydrodynamic instabilities related to the acceleration of the superbubble’s shell thanks to the sudden energy input, and subsequent mixing. We also find global oscillations of our simulated superbubbles, which produce spatial variations of the X-ray spectrum, similar to what we see in the Orion-Eridanus cavity. We calculated the fraction of energy emitted in X-rays and find that with a value of a few times 10-4, it is about a factor of ten below the measurements for nearby galaxies. Conclusions. Our models explain the observed soft spectra and peak X-ray luminosities of individual superbubbles. Each supernova event inside a superbubble produces a fairly similar heating-entrainment-cooling sequence, and the energy content of superbubbles is always determined by a specific fraction of the energy released by one supernova. For a given superbubble, soft X-rays trace the internal energy content well with moderate scatter. Some mechanism seems to delay the energy loss in real superbubbles compared to our simulations. Alternatively, some mechanism other thanthermal emission ofsuperbubbles may contribute to the soft X-ray luminosity of star-forming galaxies.Peer reviewe

A planet within the debris disk around the pre-main-sequence star AU Microscopii

AU Microscopii (AU Mic) is the second closest pre main sequence star, at a distance of 9.79 parsecs and with an age of 22 million years. AU Mic possesses a relatively rare and spatially resolved3 edge-on debris disk extending from about 35 to 210 astronomical units from the star, and with clumps exhibiting non-Keplerian motion. Detection of newly formed planets around such a star is challenged by the presence of spots, plage, flares and other manifestations of magnetic activity on the star. Here we report observations of a planet transiting AU Mic. The transiting planet, AU Mic b, has an orbital period of 8.46 days, an orbital distance of 0.07 astronomical units, a radius of 0.4 Jupiter radii, and a mass of less than 0.18 Jupiter masses at 3 sigma confidence. Our observations of a planet co-existing with a debris disk offer the opportunity to test the predictions of current models of planet formation and evolution.Comment: Nature, published June 24th [author spelling name fix

Acutihumerus patagoniensis (Sieg, 1986) (Tanaidacea: Kalliapseudidae): supplementary description and remarks on its taxonomic status

Acutihumerus patagoniensis (Sieg, 1986) was originally described based on a single specimen from Golfo Nuevo, northern Patagonia, Argentina. Over 3000 specimens referable to this species from just a few miles of its type locality are now available. Based on these specimens, the description of A. patagoniensis is completed and the ontogenetic changes of the male cheliped are described and illustrated. Acutihumerus patagoniensis has recently been considered a junior synonym of A. cavooreni (Băcescu & Absalao, 1985) from southern Brazil. However, these species can be distinguished mainly by the male chela: A. patagoniensis has a much wider notch palm than A. cavooreni. Furthermore, most of the males herein reported from off the Río de la Plata have a chela with a narrow notch, a fact that suggests that this area might be a zone of hybridization or contact between A. patagoniensis and A. cavooreni. Hence, we claim that the recently proposed synonymy has not been proven, and the resolution of this taxonomic problem must await additional specimens of A. cavooreni from its type locality (Rio Grande do Sul, Brazil).Fil: Giachetti, Clara Belen. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Roccatagliata, Daniel Carlos. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; Argentin

On the deep-sea lampropid Platytyphlops sarahae n. sp. from Argentina, with remarks on some morphological characters of Cumacea

Platytyphlops sarahae n. sp. is described based on specimens collected in the Mar del Plata submarine canyon and on the slope of the Namuncurá-Burdwood Bank. P. sarahae n. sp. is closely related to the Antarctic species Platytyphlops asperus, from which it can be easily separated by the telson having a central distal seta distinctly shorter than the other two. The presence of a rudimentary squama (exopod) on the second antenna of the male is reported for the first time for the family, and for the second time for the order Cumacea. With the aim of improving the taxonomic work and facilitating future phylogenetic analyses in the family Lampropidae, remarks on the second antenna of the male, the eyelobe and the pseudorostrum are presented.Fil: Roccatagliata, Daniel Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; Argentin

Claudicuma (Cumacea, Crustacea): First record from the marine environment, description of the second species of the genus and phylogenetic remarks

The genus Claudicuma was erected to accommodate C. platense, a species reported from freshwater and very low-salinity areas at the Río de la Plata, Argentina. Unexpectedly, a large number of the second species of this genus, C. gosztonyii n. sp., was recently collected in the Patagonian Atlantic coast, from the intertidal zone to 13 m of depth. This news species differs from C. platense, mainly in the chaetotaxia of the male second antenna, the acuteness of female pseudorostrum, and the proportions of female uropods. The ovigerous female of C. gosztonyii n. sp. has both degenerated mouthparts and an empty gut, facts that suggest that this is not a feeding instar. The second antennae of the adult male are presumably used to clasp the female. The genus Claudicuma is compared to Picrocuma, Pseudopicrocuma, Bathypicrocuma, Thalycrocuma, Atlantocuma, Almyracuma and Spilocuma, whose males also have short, clasping or vestigial second antennae. Claudicuma differs from all these genera by the coalescence of pereonites 2 and 3 in ovigerous females. The diagnosis of the genus Claudicuma is emended and its phylogenetic position discussed.Fil: Roccatagliata, Daniel Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; Argentin