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

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

On two species of diastylis (Cumacea) from the southwestern atlantic: D. sexpectinata n. sp. and D. hammoniae zimmer, 1902

Diastylis sexpectinata, a new species of cumacean that extends from São Paulo State (Brazil) to northern Patagonia (Argentina), is herein fully described and illustrated. This species can be easily distinguished from the other members of the genus by the following combination of characters: 1) carapace with a pair of anterolateral horns and six longitudinal rows of conical teeth (middle and uppermost rows poorly developed or absent in the adult male), 2) third and fourth pereiopods of the female without rudimentary exopods, and 3) uropod endopod consisting of two articles, the proximal one in the female with 3-4 teeth on outer margin. The description of the female of Diastylis hammoniae is completed and the adult male described for the first time based on its type material and additional specimens herein reported. The type species of Leptostylis (?) mancoides was also re-examined and its synonymy with Diastylis hammoniae is proposed. The synonymy of D. hammoniae with Diastylis manca is also strongly suspected, but until additional specimens become available D. manca should be treated as "species inquirenda." An identification key to the species of the genus Diastylis from Argentina and Uruguay is given.Fil: Alberico, Natalia Andrea. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; 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; Argentin

Homoeoscelis meridionalis sp. nov. (Copepoda, Nicothoidae) parasitic on two cumaceans from southern South America with comments on its biology, and partial redescription of H. frigida Hansen, 1923

The adult female and male, and the copepodite stage of the nicothoid copepod Homoeoscelis meridionalis sp. nov. are described. This parasite infests the branchial chambers of two closely related cumaceans from southern South America: Diastylis planifrons and D. fabrizioi. The maxilliped of the adult female of Homoeoscelis minuta is reillustrated, and the copepodite stage of H. frigida is briefly redescribed on the basis of their respective type materials. Of the 1768 specimens of Diastylis fabrizioi examined, 2.6% were found to be infested by Homoeoscelis meridionalis sp. nov. The copepod prevalence differs significantly between the female and male of D. fabrizioi (4.2 vs. 0.7%), and it was much higher in older instars of D. fabrizioi (adults and subadults) than in younger ones (juveniles and mancas) (7.1 vs. 0.3%).Fil: Alberico, Natalia Andrea. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; 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; Argentin

Two new cumaceans (Crustacea: Peracarida) from the South-West Atlantic with remarks on the problematic genus Holostylis Stebbing, 1912

In 1912-13, Stebbing erected the genera Holostylis and Ekdiastylis for those diastylids with the endopod of the uropods being one- and two-segmented, respectively. The validity of the genus Holostylis is still controversial and the genus Ekdiastylis continues to be suppressed. In the present contribution, two new diastylids are fully described and illustrated: one of them has the endopod of the uropod one-segmented, Holostylis uniramosa n. sp., and the other has the endopod of the uropod two-segmented, Diastylis decalineata n. sp. The genus Holostylis has currently three nominal species, which are easily distinguished from each other by the number of thoracic appendages with fully developed exopods in females: three in H. helleri (Zimmer, 1908), one in H. spinicuadata Błażewicz-Paszkowycz and Heard, 2005, and none in H. uniramosa n. sp. The validity of genus Holostylis is confirmed and its diagnosis emended. Diastylis decalineata n. sp. mainly distinguished from the other species of Diastylis with two-segmented uropod endopods by the shape and sculpture of its carapace.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; ArgentinaFil: Alberico, Natalia Andrea. 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

A new species of Pseudione sensu lato (Isopoda: Bopyridae) on a squat lobster host from the deep South-West Atlantic

A new bopyrid, Pseudione chiesai n. sp., is herein described based on an ovigerous female and an adult male found in the right branchial chamber on a specimen of Munida spinosa Henderson, 1885. This parasite was collected in the Mar del Plata submarine canyon at 819 m depth during the expedition "Talud Continental I"carried out by the Argentine RV Puerto Deseado in 2012. P. chiesai n. sp. belongs to the Pseudione "crénelés"group sensu Bourdon (1972, 1976), which currently contains seven species, all of which have galatheoid crabs as hosts. P. chiesai n. sp. can be separated from the other species in the Pseudione "crénelés"group by the following combination of characters: (1) both sides of the body convex, (2) frontal lamina with a few, shallow indentations, (3) coxal plates 1-4 and tergal projections 1-4 with distinct irregular margins, mainly on the right side, (4) pereomeres 5-7 with single/branched lateral digitations, (5) maxilliped palp well-developed and setose, and (6) pleon with lateral plates 1-5 distally rounded and directed laterally. The taxonomic position of this new species is briefly discussed.Fil: Pereira, Emanuel. 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: 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: 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