A comparative study of populations of Ectopleura crocea and Ectopleura ralphi (Hydrozoa, Tubulariidae) from the Southwestern Atlantic Ocean

Ectopleura crocea (L. Agassiz, 1862) and Ectopleura ralphi (Bale, 1884) are two of the nominal tubulariid species re-corded for the Southwestern Atlantic Ocean (SWAO), presumably with wide but disjunct geographical ranges and similar morphologies. Our goal is to bring together data from morphology, histology, morphometry, cnidome, and molecules (COI and ITS1+5.8S) to assess the taxonomic identity of two populations of these nominal species in the SWAO. We have ob-served no significant difference or distributional patterns between the so-called Brazilian E. ralphi and Argentine E. cro-cea for both morphological and molecular data. Therefore, SWAO populations of Ectopleura belong to the same species. In a broader view, it is difficult to find decisive character distinguishing E. crocea from E. ralphi, and both species have indeed recently been synonymized, with the binomen E. crocea having nomenclatural priority. Geographically broader genetic analysis should be carried out in order to test the validity of this synonymy because taxonomical procedures such as studying type specimens and documenting broad phenotypic variability have not yet been conducted.Fil: Antunes Imazu, Mauricio. Universidade de Sao Paulo; BrasilFil: Ale, Ezequiel. Universidade de Sao Paulo; BrasilFil: Genzano, Gabriel Nestor. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentin

Riqueza específica y patrones de distribución de equinodermos en el Atlántico Sudoccidental entre los 34 y 56°S

El objetivo de este estudio es recopilar y analizar la información histórica disponible sobre equinodermos en el Atlántico Sudoccidental, a fin de elaborar una síntesis del estado de conocimiento actual, identificar patrones de distribución geográfica de las comunidades de equinodermos y poner a prueba la validez del esquema zoogeográfico tradicionalmente establecido para el área de estudio. Este estudio se llevó a cabo en la Plataforma Continental Argentina entre los 34 y 56°S. Se efectuó una intensiva búsqueda de datos geo-referenciados sobre las especies de equinodermos, a fin de crear una base de datos histórica. Se utilizaron análisis multivariados para analizar cambios en la composición específica a través de gradientes latitudinales y batimétricos, así como también para reconocer y diferenciar las asociaciones de equinodermos en el área de estudio. Los resultados confirmaron la existencia de dos asociaciones faunísticas que responden al esquema zoogeográfico tradicionalmente establecido para el área de estudio, distinguiendo dos Provincias Biogeográficas: Argentina y Magallánica. La Provincia Argentina presentó cuarenta y seis especies ampliamente distribuidas. Ochenta y seis especies fueron registra- das en la Provincia Magallánica, un alto porcentaje de las mismas también se encontraron en aguas de la Antártida (25%), lo que sugiere una fuerte conexión entre la fauna de equinodermos entre esta provincia y la Región Antártica. La riqueza de especies entre los 34 y 56°S en el Océano Atlántico mostró un aumento significativo en referencia a la latitud, los valores más altos se registraron entre los 46 y 56°S. En vista del alto porcentaje de especies compartidas con la Antártida, considerada una región con una diversidad muy alta de equinodermos, el patrón de distribución de la riqueza de especies observado en el área de estudio podría responder a una dispersión de especies antárticas hacia aguas subantárticas.The aim of this study was to compile and analyse available historical information on echinoderms in the southwestern Atlantic Ocean in order to make a synthesis of present taxonomical knowledge, to identify patterns of geographical distribution of echinoderm assemblages and to test the validity of the current zoogeographic scheme for this group. This study was conducted on the Argentinean continental shelf, southwestern Atlantic Ocean (34-56°S). An intensive research on geo-referenced data was carried out to make a knowledge synthesis on echinoderm species and thus create a historical database. Multivariate analysis was used to analyse the faunal composition through latitudinal and bathymetric gradients as well as echinoderm associations. The results confirmed the existence of two faunal associations that correspond to the traditional zoogeographic scheme established for the Argentine Sea: the Argentinean and Magellan Provinces. The Argentinean Province had 46 widely distributed species. Of the 86 species recorded in the Magellan Province, a high percentage (25%) were also found in Antarctic waters, suggesting a strong connection between the echinoderm fauna of this province and the Antarctic Region. The species richness between 34 and 56°S in the Atlantic Ocean showed a significant increase in reference to latitude, with the highest values being recorded between 46 and 56°S. In view of the high percentage of shared species with Antarctica, considered a hot-spot region in terms of echinoderm diversity, the pattern of distribution of species richness observed in our study area could correspond to a dispersion of this species from Antarctic to sub-Antarctic regions.Fil: Souto, Valeria Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Escolar, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Subsede Instituto Nacional de Investigación y Desarrollo Pesquero; ArgentinaFil: Genzano, Gabriel Nestor. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Bremec, Claudia Silvia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentin

Sucesión estacional de zooplancton gelatinoso (Medusae y ctenophores) del puerto de Mar del Plata, Argentina (Océano Atlántico sudoccidental)

Temporal variation of the population dynamics of the medusae and ctenophores (gelatinous zooplankton) is described over an annual cycle in the Mar del Plata Harbor, Argentina. A total of 18 species was identified, three of which were ctenophores (two of Class Tentaculata and one of Nuda) and 15 medusae (14 of Class Hydrozoa and one of Scyphozoa). A species of hydromedusae, Annatiara affinis, was observed for the first time in the Argentine Sea. In both groups, species richness and abundances showed clear seasonality, with the lowest values in the cold period (austral autumn-winter) and the highest values in the warm period (spring-summer). The meroplanktonic medusae Obelia sp. and Eucheilota ventricularis as well as the holoplanktonic Liriope tetraphylla represented 94.2% of the total abundances of this group (classified as dominant). In the ctenophores, the dominant species were Pleurobrachia pileus and Mnemiopsis leidyi, which accounted for 99.3% of the ctenophores. Monthly medusae succession indicated that holoplanktonic species were dominant over practically all the annual cycle in terms of abundance, while considering species richness values, meroplanktonic species dominated. Ctenophores (considering abundance values) was displayed alternating periods of approximately three months of dominance between P. pileus and M. leidyi. The Bray-Curtis similarity index performed on medusae identified two groups of seasons with faunal affinity, the 1) cold and 2) warm periods, with the water temperature and non-gelatinous zooplankton abundances as the environmental factors that best explained this variability (BIO-ENV analysis), while for ctenophores, temporal faunal homogeneity was observed and a single group with faunal affinity was identified.Se describe la variación estacional de la dinámica poblacional de las medusas y ctenóforos (zooplancton gelatinoso) a lo largo de un ciclo anual en el puerto de Mar del Plata, Argentina. Se identificaron un total de 18 especies, de las cuales 3 fueron ctenóforos (2 de la clase Tentaculata y 1 de Nuda) y 15 medusas (14 de la clase Hydrozoa y 1 de Scyphozoa). La hidromedusa Annatiara affinis representó un nuevo registro para el Mar Argentino. En ambas agrupaciones, la riqueza específica y las abundancias mostraron los valores más bajos en el período frío (otoño-invierno austral) y los más altos en el período cálido (primavera-verano). Las medusas meroplanctónicas Obelia sp. y Eucheilota ventricularis, así como la holoplactónica Liriope tetraphylla, representaron el 94.2% del total de las abundancias de este grupo (clasificadas como dominantes). En los ctenóforos, las especies dominantes fueron Pleurobrachia pileus y Mnemiopsis leidyi, que representaron el 99.3%. La sucesión mensual en las medusas indicó que las especies holoplanctónicas fueron dominantes casi en todo el ciclo anual en términos de abundancia, mientras que, sobre la base del número de especies, las meroplanctónicas presentaron valores mayores. En los ctenóforos (considerando sus abundancias), se observaron períodos intercalados de ~3 meses de dominancia entre M. leidyi y P. pileus. El índice de Bray-Curtis aplicado a las medusas identificó la presencia de dos agrupaciones de estaciones climáticas con afinidad faunística: 1) frío y 2) cálido; los factores ambientales que mejor explicaron dicha variabilidad fueron la temperatura del agua y las abundancias del zooplancton no gelatinoso (análisis BIO-ENV). En el caso de los ctenóforos, se observó una homogeneidad faunística temporal y se identificó un solo grupo con afinidad de especies.Fil: Puente Tapia, Francisco Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata. Facultad de Cs.exactas y Naturales. Departamento de Cs.marinas. Estación "j.j.nagera" Grupo Medusas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Genzano, Gabriel Nestor. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata. Facultad de Cs.exactas y Naturales. Departamento de Cs.marinas. Estación "j.j.nagera" Grupo Medusas; Argentin

Hydromedusae (Cnidaria: Hydrozoa) from the temperate southwestern Atlantic Ocean: a review

Hydromedusae are one of the best-represented planktonic groups in waters of the South Atlantic Ocean in terms of species richness. Nevertheless, medusae of the region are inadequately known because earlier studies have been limited and restricted to few areas. During the last two decades, almost 2000 samples from 54 research cruises have been collected, mostly within the continental shelf of Argentina and Uruguay (33 - 55° S). These samples provide an opportunity to significantly augment knowledge of the richness of the medusa fauna in the southwest Atlantic. Forty species of hydromedusae (six of them new records for the area), including 15 of Anthomedusae, 14 of Leptomedusae, three of Limnomedusae, four of Narcomedusae, and four of Trachymedusae, were identified. Our results indicate that previous lists overestimated species richness of hydromedusae in the area. When misidentifications, updated species synonymies, and doubtful records are taken into account, 71 valid species are recognized here from the study area. Based upon this corrected inventory list, the data suggest that the number of species of hydromedusae decreases markedly with increasing latitude, corresponding with that observed in other planktonic groups of invertebrates.Fil: Genzano, Gabriel Nestor. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Mianzan, Hermes Walter. Instituto Nacional de Investigaciones y Desarrollo Pesquero; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Bouillon, Jean. Université Libre de Bruxelles; Bélgic

Primer registro de la medusa urticante invasora Gonionemus vertens en el hemisferio sur (Mar del Plata, Argentina)

En este trabajo registra el primer hallazgo de la hidromedusa Gonionemus vertens Agassiz, 1862 en el hemisferio sur. Alrededor de 30 medusas recientemente liberadas fueron encontradas en un acuario en septiembre de 2008. Este acuario contenía muestras bentónicas colectadas en la franja rocosa intermareal y submareal de Mar del Plata, cerca de uno de los puertos más importantes de Argentina. Las medusas fueron alimentadas con Artemia salina hasta su maduración gonadal. Se discute la posible vía de introducción de esta especie.In this paper we report the first finding of the hydromedusa Gonionemus vertens Agassiz, 1862 in the southern hemisphere. About thirty newly released medusae were found within an aquarium on September 2008. The aquarium contained benthic samples collected in intertidal and subtidal rocky fringe off Mar del Plata, near a commercially important harbor in Argentina. Medusae were feed with Artemia salina until sexual maturation. Possible way of species introduction is discussed.Fil: Rodriguez, Carolina Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Pujol, M. G.. Provincia de Buenos Aires. Municipalidad de General Pueyrredon. Secretaría de Cultura. Museo Municipal de Ciencias Naturales Lorenzo Scaglia; ArgentinaFil: Mianzan, Hermes Walter. Instituto Nacional de Investigaciones y Desarrollo Pesquero; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Genzano, Gabriel Nestor. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigaciones Marinas y Costeras; Argentin

Spatial distribution of medusa Cunina octonaria and frequency of parasitic association with Liriope tetraphylla (Cnidaria: Hydrozoa: Trachylina) in temperate Southwestern Atlantic waters

This study examined the spatial distribution of the medusae phase of Cunina octonaria (Narcomedusae) in temperate Southwestern Atlantic waters using a total of 3,288 zooplankton lots collected along the Uruguayan and Argentine waters (34-56°S), which were placed in the Medusae collection of the Universidad Nacional de Mar del Plata, Argentina. In addition, we reported the peculiar parasitic association between two hydrozoan species: the polypoid phase (stolon and medusoid buds) of C. octonaria (parasite) and the free-swimming medusa of Liriope tetraphylla (Limnomedusae) (host) over a one-year sampling period (February 2014 to March 2015) in the coasts of Mar del Plata, Argentina. We examined the seasonality, prevalence, and intensity of parasitic infection. Metadata associated with the medusa collection was also used to map areas of seasonality where such association was observed. Cunina octonaria was found from southern Uruguay to the coast of Mar del Plata (34.8-38.2°S, 57.2-54.0°W), with the highest abundances and frequency of occurrence in the Río de la Plata estuary. The parasitic association was identified from the austral warm period (spring-summer season) until midautumn. Out of the 21,734 L. tetraphylla specimens that were examined, 316 were parasitized (prevalence= 1.5%) exclusively in the manubrium and gastric peduncle, with an infection intensity of 1 to 2 stolons per host. Furthermore, the medusoid buds per stolon ranged from 11 and 29 at different stages of development. No significant differences were observed between the umbrella diameter of parasitized and non-parasitized L. tetraphylla specimens, nor was any significant correlation identified between umbrella diameter and prevalence, and intensity of infection. According to the aggregation coefficient, C. octonaria had an overdispersed distribution in the host population. All parasitized hosts showed stomach vacuity due to the location of the stolon, which blocked the mouth of the host. We identified the parasitic association in the coasts of Mar del Plata, as well as in both coasts of the Río de la Plata Estuary (Uruguayan-Argentinean coasts). In the Southwestern Atlantic, several biological interactions between medusae and other groups have been identified; however, the specific host selectivity of C. octonaria for L. tetraphylla was not previously identified. Here we discuss the ecological importance of this association during the holoplanktonic life history of the narcomedusae. Additionally, we report the southern limit of the spatial distribution of this particular parasitic association in the Southwestern Atlantic, thus increasing the knowledge of biological associations of gelatinous zooplankton (Cnidaria and Ctenophora) on Uruguayan and Argentinean coasts.Fil: Puente Tapia, Francisco Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Subsede Instituto Nacional de Investigación y Desarrollo Pesquero; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Castiglioni, Florencia. Universidad de la República; UruguayFil: Failla Siquier, Gabriela. Universidad de la República; UruguayFil: Genzano, Gabriel Nestor. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Subsede Instituto Nacional de Investigación y Desarrollo Pesquero; Argentin

Medusae and ctenophores from the Bahia Blanca Estuary and neighboring inner shelf (Southwest Atlantic Ocean, Argentina)

An updated checklist of medusae and ctenophores is presented for the first time for the area comprised by the Bahía Blanca Estuary, the adjacent shelf El Rincón and Monte Hermoso beach, on the southwest coast of Buenos Aires province (Argentina). The area is highly productive and provides several ecosystem services including fishing and tourism. Updated information on the biodiversity of medusae and ctenophores species is essential for the study area, given that these species can affect ecosystem services. The list includes 23 hydromedusae, 3 scyphomedusae, and 3 ctenophores. Five hydromedusae (Halitiara formosa, Amphinema dinema, Aequorea forskalea, Clytia lomae and Halopsis ocellata) were firstly observed in this area. Three species of medusae, 2 hydromedusae (Olindias sambaquiensis and Liriope tetraphylla) and 1 scyphomedusae (Chrysaora lactea) pose a potential health risk, due to their toxicity to humans. Considering the size of the study area, the Bahía Blanca region has a comparatively high species richness of hydromedusae, higher than larger zones previously studied along the temperate SW Atlantic Ocean. The present report provides the baseline knowledge of gelatinous species for the Bahía Blanca region.Fil: Dutto, María Sofía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; ArgentinaFil: Genzano, Gabriel Nestor. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Schiariti, Agustin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina. Instituto Nacional de Investigaciones y Desarrollo Pesquero; ArgentinaFil: Lecanda, Maria Julieta. Museo Municipal de Ciencias Naturales de Monte Hermoso; Argentina. Universidad Nacional del Sur; ArgentinaFil: Hoffmeyer, Monica Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentina. Universidad Tecnológica Nacional; ArgentinaFil: Pratolongo, Paula Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; Argentin

Macroscale abundance patterns of hydromedusae in the temperate Southwestern Atlantic (27º-56º S)

Gelatinous organisms are crucial components of marine ecosystems and some species imply social and economic consequences. However, certain geographic areas, such as the temperate Southwestern Atlantic (SWA, 27 - 56 S), remain understudied in terms of jellyfish ecological data. We analyzed 3,727 plankton samples collected along ~6.7 million km2 over a 31-year period (1983–2014) to determine the occurrence, abundance, and diversity patterns of hydromedusae in the SWA. Analyses were made at both community and species levels. Two abundance hot spots of hydromedusae were identified, where values up to 2,480 ind. m-3 were recorded between 2003 and 2014. Liriope tetraphylla and Obelia spp. were the main responsible for recurrent peaks. Diversity indexes were in the range of those published for temperate areas worldwide, and some coastal zones showed values that can be considered moderate to high for a temperate neritic region. The community analysis yielded 10 groups following previously determined biogeographic schemes throughout the study area. This work enhances the knowledge of hydromedusae in the SWA and provides essential information about the current global warming context and the gelatinous zooplankton data necessity.Fil: Dutto, María Sofía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; ArgentinaFil: Chazarreta, Carlo Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; ArgentinaFil: Rodriguez, Carolina Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Schiariti, Agustin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina. Instituto Nacional de Investigaciones y Desarrollo Pesquero; ArgentinaFil: Diaz Briz, Luciana Mabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Genzano, Gabriel Nestor. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentin

Reassessment of morphological siagnostic characters and species boundaries requires taxonomical changes for the genus Orthopyxis L. Agassiz, 1862 (Campanulariidae, Hydrozoa) and some related Campanulariids

The genus Orthopyxis is widely known for its morphological variability, making species identification particularly difficult. A number of nominal species have been recorded in the southwestern Atlantic, although most of these records are doubtful. The goal of this study was to infer species boundaries in the genus Orthopyxis from the southwestern Atlantic using an integrative approach. Intergeneric limits were also tested using comparisons with specimens of the genus Campanularia. We performed DNA analyses using the mitochondrial genes 16S and COI and the nuclear ITS1 and ITS2 regions. Orthopyxis was monophyletic in maximum likelihood analyses using the combined dataset and in analyses with 16S alone. Four lineages of Orthopyxis were retrieved for all analyses, corresponding morphologically to the species Orthopyxis sargassicola (previously known in the area), Orthopyxis crenata (first recorded for the southwestern Atlantic), Orthopyxis caliculata (= Orthopyxis minuta Vannucci, 1949 and considered a synonym of O. integra by some authors), and Orthopyxis mianzani sp. nov. A re-evaluation of the traditional morphological diagnostic characters, guided by our molecular analyses, revealed that O. integra does not occur in the study area, and O. caliculata is the correct identification of one of the lineages occurring in this region, corroborating the validity of that species. Orthopyxis mianzani sp. nov. resembles O. caliculata with respect to gonothecae morphology and a smooth hydrothecae rim, although it shows significant differences for other characters, such as perisarc thickness, which has traditionally been thought to have wide intraspecific variation. The species O. sargassicola is morphologically similar to O. crenata, although they differ in gonothecae morphology, and these species can only be reliably identified when this structure is present.Coordenação de Aperfeiçoamento de Pessoal de Nível Superio (Capes)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) (grant no. 562143/2010-6; 563106/2010-7; 564945/2010-2; 477156/2011-8; 458555/2013-4; 305805/2013-4) (ACM)São Paulo Research Foudation (FAPESP) (grant no. 2004/ 09961-4; 2010/52324-6; 2011/50242-5; 2013/50484-4 – ACM, 2011/22260-9 – AFC),Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) (grant no. PIP 0152 CONICET) (GNG

Areas of endemism in the Southwestern Atlantic Ocean based on the distribution of benthic hydroids (Cnidaria: Hydrozoa)

Geographic distributions of 130 species of benthic hydroids were used to infer areas of endemism in the Southwestern Atlantic Ocean (SWAO, between 22°S and 55°S). Endemicity Analysis (EA) was carried out with the software NDM VNDM, using a 2° x 2° grid with different values of F (F = 0.5 and F = 1.0) for inferred presence. Hypothesized areas of endemism (16 with F = 0.5 and 13 with F = 1.0) formed three generalized patterns: (1) Tropical, (2) Subtropical, and (3) disjunctions along Tropical and Subtropical areas. Areas of endemism estimated here were compared with provinces, ecoregions and areas of endemism previously defined (but not based on algorithmic analysis) in the literature. Ecological and historical aspects that are potentially relevant for the SWAO realm were contrasted, related and discussed to areas of endemism. This is the first study to apply NDM VNDM to the marine realm and one of the few that focuses on the SWAO.CAPES Proap-2008, Procad and Pró-Equipamentos 1887/2007CNPq (Proc. 490348/2006-8, 304720/2009-7, 562143/2010-6, 563106/2010-7, 458555/2013-4)EXA 734/15 (UNMdP)FAPESP (Proc. 2004/09961-4, 2006/58226-0, 2010/52324-6, 2010/06927-0, 2011/50242-5, 2013/50484-4, 2014/ 24407-5)PIP–CONICET 2012NP-BioMar, US