Free-living marine nematode communities: In San Jorge gulf, Argentina

The aim of this study was to investigate the patterns of nematode diversity and community structure in San Jorge Gulf, Argentina, in order to improve knowledge of this key group of organisms. Free-living marine nematodes were sampled at 13 stations in February 2014 during an expedition aboard R/V Coriolis II. We found a total of 188 species (101 of which were new to science) belonging to 98 genera. The statistical results indicated the presence of three different assemblages of free-living marine nematodes distributed spatially in three distinct zones in the gulf: the central part, the outer thermal front at both sides of the entrance, and the south thermal front area. Diversity increased from the coast to the entrance of the gulf, and the highest diversity was found in areas with coarser sediment. Sediment and salinity were the environmental parameters that best matched nematode community distribution.Fil: Pastor de Ward, Catalina T.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Diversidad y Evolución Austral; ArgentinaFil: Lo Russo, Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Diversidad y Evolución Austral; ArgentinaFil: Varisco, Martin Alejandro. Universidad Nacional de la Patagonia Austral. Centro de Investigaciones y Transferencia Golfo San Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia Golfo San Jorge. Universidad Nacional de la Patagonia "San Juan Bosco". Centro de Investigaciones y Transferencia Golfo San Jorge; Argentin

Two new species of Enoplolaiminae (Enoplida: Thoracostomopsidae) from Río Negro and Chubut, Argentina

Two new species of free-living marine nematodes of the subfamily Enoplolaiminae are described from Río Negro and Chubut Provinces, Argentina. Enoplolaimus variispiculum sp. n. is characterized by having asymmetric spicules, different in size and distal tips. It is the only species with this characteristic in the whole genus. Mesacanthoides flagellatum sp. n. is characterized by mandibles texture, weakly cuticularized and mottled and mandibular plates with pronounced “v” shaped incision posterior to the anterior bar. Cephalic capsule wider than long with setae on posterior end, males with long spicules, complex gubernaculum and flagellate tail.Fil: Pastor, Catalina Teresa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Diversidad y Evolución Austral; ArgentinaFil: Lo Russo, Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Diversidad y Evolución Austral; Argentin

Three new species of Mesacanthion Filipjev, 1927 (Nematoda: Thoracostomopsidae) from Argentine coasts

Three new species of Mesacanthion Filipjev, 1927 were found along Patagonian coasts (Argentina). Mesacanthion bifidum sp. nov. is characterized by short labial and cephalic setae, onchia of equal size, spicule arcuate, and gubernaculum with caudal apophysis, ending in two teeth. The species is related to M. virile (Ditlevsen, 1930) De Coninck & Schuurmans Stekhoven, 1933. However, the spicules and gubernaculum of both species are different in shape. Mesacanthion longigubernaculum sp. nov. is characterized by its long and slender body, striated cuticle, relatively long cephalic and cervical setae, onchia of different sizes, amphidial fovea lentil-shaped, spicule arcuate, gubernaculum surrounding the spicule, and tail conical-cylindrical with terminal setae. Mesacanthion sanantoniensis sp. nov. is characterized by its long and stout body, striated cuticle, long cephalic setae, onchia of different sizes, amphidial fovea pouch-shaped, spicule arcuate, gubernaculum with dorsal apophysis, and tail conical without terminal setae. Following the key of Jeong et al. (2019), the last two species are related to M. pali Wieser, 1959 and M. longissimesetosum Wieser, 1953, so we provide a key to differentiate the four species.Fil: Lo Russo, Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Diversidad y Evolución Austral; ArgentinaFil: Pastor, Catalina Teresa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Diversidad y Evolución Austral; Argentin

Free-living marine nematodes from San Antonio Bay (Río Negro, Argentina)

The dataset of free-living marine nematodes of San Antonio Bay is based on sediment samples collected in February 2009 during doctoral theses funded by CONICET grants. A total of 36 samples has been taken at three locations in the San Antonio Bay, Santa Cruz Province, Argentina on the coastal littoral at three tidal levels. This presents a unique and important collection for benthic biodiversity assessment of Patagonian nematodes as this area remains one of the least known regions. In total 7,743 specimens of free-living marine nematodes belonging to two classes, eight orders, 37 families, 94 genera and 104 species were collected.Fil: Villares, Maria Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Lo Russo, Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Diversidad y Evolución Austral; ArgentinaFil: Pastor, Catalina Teresa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Diversidad y Evolución Austral; ArgentinaFil: Milano, Viviana. Universidad Nacional de la Patagonia; ArgentinaFil: Miyashiro, Lidia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Mazzanti, Renato. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentin

A new species of Pontonema (Oncholaimidae, Nematoda) and a redescription of Pontonema incisum Wieser, 1953 from Santa Cruz and Chubut Provinces, Argentina

Pontonema golfonuevensis sp. nov. from Chubut Province, Argentina is described and a description of the male of Pontonema incisum Wieser, 1953 from Chubut and Santa Cruz provinces is provided. Pontonema golfonuevensis sp. nov. is characterized by having the slender sub-ventral teeth 25 µm long located at 24 % of stoma length, a short, broad dorsal tooth at 60 % of stoma length, excretory pore opening at level of base of the buccal cavity, and by having a ventral precloacal sensory field with four papillae and a glandular sub-ventral area with seven papilliform sensillae. The male of P. incisum has long slender sub-ventral teeth at 36 % of stoma length, a short broad dorsal tooth at 72 % of stoma length, excretory pore about two buccal cavity lengths from the anterior end, and a ventral precloacal sensory field without papillae and a glandular sub-ventral area with twelve to fourteen papilliform sensillae. A key for identification of males of Pontonema is presented.Fil: Villares, Maria Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Lo Russo, Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Pastor, Catalina Teresa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentin

Three new species and one new record of Campylaimus (Diplopeltidae, Nematoda) from Argentine coasts (Buenos Aires and Santa Cruz, Argentina)

Two new Campylaimus species from Arroyo Pareja, Buenos Aires province and one new species and one new record of Campylaimus from Puerto San Julián, Chubut province are described. The three species are characterized by the shape of the copulatory apparatus of the male and the presence of precloacal papillae. Campylaimus bonariensis sp. nov. has slender and arcuate spicules, with well-developed cephalization at the proximal end, tubular gubernaculum and three precloacal papillae; Campylaimus arcuatus sp. nov. has curved spicules, with well-developed cephalization at the proximal end, gubernaculum with dorso-caudally directed apophysis and five precloacal papillae; Campylaimus patagonicus sp. nov. has slender and arcuate spicules without proximal cephalization, gubernaculum with dorso-caudally directed apophysis and two precloacal papillae. An emended diagnosis of the genus Campylaimus and an identification key to species based on male characters are givenFil: Villares, Maria Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Martelli, Antonela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Lo Russo, Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Pastor, Catalina Teresa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentin

Timing of fission in the starfish Allostichaster capensis (Echinodermata:Asteroidea) in laboratory

Timing of fission in the fissiparous starfish Allostichaster capensis under laboratory conditions is described. A. capensis generally splits across the disc along the fission plane during the spring, and then each half regenerates the missing arms during the rest of the year. The fission process can last eight hours. The healing process starts immediately after fission. A. capensis has impressive regeneration ability, including a comet, without signs of disc, regenerated two new arms.Fil: Rubilar Panasiuk, Cynthia Tamara. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Pastor, Catalina Teresa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Díaz de Vivar, María Enriqueta Adela. Universidad Nacional de la Patagonia "San Juan Bosco"; Argentin

The dilemmas of parental mediation: continuities from parenting in general

This article examines how much parent-child interactions around the online world reflect broader, more long-standing parent-child relations and parenting dilemmas. It does so through exploring the meanings that parents give to their parenting practices and the beliefs that underlie parental mediation their children's online activities as well as the reasons for any differences between their broader normative approach to parental mediation and their actual practices. Qualitative in-depth interviews conducted with 26 Spanish parents of children aged 9 to 16-years-old found that many parents favoured the managed progression of children towards more autonomy and gave reasons why it was important to trust older children. However, the analysis explores a range of dilemmas parents experience when trying to implement these ideals, where issues of privacy, trust and managing that progression all proved to be problematic

New species of Epacanthion (Nematoda: Thoracostomopsidae) from Patagonia coast, Río Negro and Chubut, Argentina

Two new free-living marine nematodes belonging to the family Thoracostomopsidae,subfamily Enoplolaiminae and the genera Epacanthion are described from Patagonian coastal areas, Río Negro and Chubut provinces of Argentina. In Epacanthion bicuspidatum sp. nov. the main features are: two cusps on distal mandible end, presence of two rings of eight setae in the cervical region and eight setae in crown-shaped along the body, presence of one supplement distant two cbd from cloacae, gubernaculum and short spicule. Epacanthion ampullatum sp. nov. is characterized by having a tubular and long precloacal supplement, short spicule, presence of gubernaculum, presence of three long setae on the tip of the tail, the presence of one supplement distant three cbd from cloacae and the presence of two small cusps on the distal end of the mandible.Fil: Lo Russo, Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagonico; Argentina;Fil: Villares, Maria Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagonico; Argentina;Fil: Martelli, Antonela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagonico; Argentina;Fil: Pastor, Catalina Teresa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagonico; Argentina;Fil: Harguinteguy, Carlos Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentina

Response of estuarine free-living nematode assemblages to organic enrichment:an experimental approach

Organic enrichment, especially from anthropogenic sources, is one of the currentthreats to coastal marine biodiversity. Organic enrichment occurs mainly in sheltered soft bottoms,characterized by fine sediments, and results in multiple changes in the benthic habitat, includinghypoxia and an increased concentration of compounds that are toxic to marine invertebrates. Wereport on the results of a microcosm-based experiment (duration = 30 d), quantifying the effects oforganic enrichment on taxonomic and functional diversity of nematode assemblages from anopen/closed coastal lagoon of South America (Rocha Lagoon, Uruguay). In open/closed lagoons,the input of organic matter becomes a major disturbance due the limitation in water renewal. Inour experiment, enrichment led to reductions in abundance, richness and trophic diversity of thenematode assemblage. Rapid reductions in total abundance (after 4 d) were registered, while richnessdecreased only towards the end of the experiment (~30 d). Trophic changes were characterizedby loss of predators/omnivores and dominance of selective deposit-feeders and epigrowthfeeders.By contrast, we did not find any selective effect of enrichment associated with life historytraits (e.g. maturity index). Overall, these findings have 2 important implications for the conservationand monitoring of the health of coastal lagoons: first, monitoring of nematode assemblages atthe genus level is sufficient to detect enrichment effects; second, an index of trophic diversitywould be a good indicator of the effects of enrichment on natural communities.Fil: Kandratavicius, Noelia. Universidad de la República de Uruguay; UruguayFil: Pastor, Catalina Teresa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Diversidad y Evolución Austral; ArgentinaFil: Venturini, Natalia. Universidad de la República de Uruguay; UruguayFil: Giménez, Luis. Bangor University; Reino UnidoFil: Rodriguez, Marcel. Universidad de la República de Uruguay; UruguayFil: Muniz, Pablo. Universidad de la República de Uruguay; Urugua