Revision of some ophiuroid records (Echinodermata: Ophiuroidea) from Argentina

The taxonomy of some ophiuroids reported from off Argentina, western Antarctica and the SW Atlantic Ocean is reviewed. The species Amphilepis sanmatiensis, known only from the small holotype, is a synonym of Amphioplus lucyae. This synonymy removes the only reported endemic ophiuroid from Argentina. The species name ?Ophiacantha ingrata Koehler, 1923? used for specimens from South Georgia is invalid; the specimens are likely to belong to one of two cryptic species within the O. vivipara complex. Specimens of Amphiura joubini reported from Argentina are re-identified as Amphiura princeps, and specimens of Ophiactis amator from the Antarctic Peninsula are re-identified as Ophiactis asperula.Fil: Brogger, Martin Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales; ArgentinaFil: O'hara, Timothy D.. Museum Victoria; Australi

Reflection-on-action in qualitative research processes: deconstructing research and developing an honest critical self-appraisal rubric.

In this paper, four critical friends meet to discuss qualitative research practices. Together they put one of their own case studies under the knife and deconstruct it to investigate the possibilities that knowledge work is complicated not only by the dynamics of socially constructed enterprises and the actors involved therein, but by the positioning of the researcher. The case describes an evaluative study of a university programme where students engaged in directed experiential learning in group integrated learning settings. The researcher was also the course lead-tutor and this gave rise to some concern, on later reflection and in discussions among critical friends, when issues of researcher positioning were considered. Together, through questioning the topic, the literature, the research experience and the role of the researcher, we developed a reflection-on-action rubric. In a research arena where subjective, interpretative and messy examples abound, as they should, this paper offers an example of our own work, an honest self-appraisal, a rubric for readers’ consideration and a discussion that adds to the perpetual flux of knowledge work

Studies of the Structure and Evolution of the Intracluster Medium

124 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2007.Finally, we examine how scaling relations evolve with redshift using a 70 cluster sample over the redshift range 0.18 < z < 1.24. We show that X-ray luminosity and ICM mass evolve more slowly toward higher redshifts than is predicted by self-similar models of cluster formation. Effects of core structure are again apparent in this work, as scaling relations constructed from core subtracted quantities evolve differently from those using non-core subtracted quantities, and the scatter in scaling relations and in central surface brightness increases at low redshift.Ope

Against the flow: evidence of multiple recent invasions of warmer continental shelf waters by a Southern Ocean brittle star

The Southern Ocean is anomalously rich in benthos. This biodiversity is native, mostly endemic and perceived to be uniquely threatened from climate- and anthropogenically- mediated invasions. Major international scientific effort throughout the last decade has revealed more connectivity than expected between fauna north and south of the worlds strongest marine barrier – the Polar Front (the strongest jet of the Antarctic Circumpolar Current). To date though, no research has demonstrated any radiations of marine taxa out from the Southern Ocean, except at abyssal depths (where conditions differ much less). Our phylogeographic investigation of one of the most ubiquitous and abundant clades at high southern latitudes, the ophiuroids (brittlestars), shows that one of them, Ophiura lymani, has gone against the flow. Remarkably our genetic data suggest that O. lymani has successfully invaded the South American shelf from Antarctica at least three times, in recent (Pleistocene) radiation. Many previous studies have demonstrated links within clades across the PF this is the first in which northwards directional movement of a shelf-restricted species is the only convincing explanation. Rapid, recent, regional warming is likely to facilitate multiple range shift invasions into the Southern Ocean, whereas movement of cold adapted fauna (considered highly stenothermal) out of the Antarctic to warmer shelves has, until now, seemed highly unlikely

Unexpected high abyssal ophiuroid diversity in polymetallic nodule fields of the Northeast Pacific Ocean, and implications for conservation

The largest and commercially appealing mineral deposits can be found in the abyssal seafloor of the Clarion-Clipperton Zone (CCZ), a polymetallic nodule province, in the NE Pacific Ocean, where experimental mining is due to take place. In anticipation of deep-sea mining impacts, it has become essential to rapidly and accurately assess biodiversity. For this reason, ophiuroid material collected during seven scientific cruises from five exploration license areas within CCZ, one area protected from mining (APEI3, Area of Particular Environmental Interest) in the periphery of CCZ and the DIS-turbance and re-COLonisation (DISCOL) Experimental Area (DEA), in the SE Pacific Ocean, was examined. Specimens were genetically analysed using a fragment of the mitochondrial cytochrome c oxidase subunit I (COI). Maximum Likelihood and Neighbour Joining trees were constructed, while four tree-based and distance-based methods of species delineation (ABGD, BINs, GMYC, mPTP) were employed to propose Secondary Species Hypotheses (SSHs) within the ophiuroids collected. The species delimitations analyses concordant results revealed the presence of 43 deep-sea brittle stars SSHs, revealing an unexpectedly high diversity and showing that the most conspicuous invertebrates in abyssal plains have been so far considerably under-estimated. The number of SSHs found in each area varied from 5 (IFREMER area) to 24 (BGR area), while 13 SSHs were represented by singletons. None of the SSHs was found to be present in all 7 areas, while the majority of species (44.2 %) had a single-area presence (19 SSHs). The most common species were Ophioleucidae sp. (Species 29), Amphioplus daleus (Species 2) and Ophiosphalma glabrum (Species 3), present in all areas except APEI3. The biodiversity patterns could be mainly attributed to POC fluxes that could explain the highest species numbers found in BGR (German contractor area) and UKSRL (UK contractor area) areas. The five exploration contract areas belong to a mesotrophic province, while in contrary the APEI3 is located in an oligotrophic province which could explain the lowest diversity as well as very low similarity with the other six study areas. Based on these results the representativeness and the appropriateness of APEI3 to meet its purpose of preserving the biodiversity of the CCZ fauna are questioned. Finally, this study provides the foundation for biogeographic and functional analyses that will provide insight into the drivers of species diversity and its role in ecosystem function

Unexpected high abyssal ophiuroid diversity in polymetallic nodule fields of the Northeast Pacific Ocean, and implications for conservation

The largest and commercially appealing mineral deposits can be found in the abyssal seafloor of the Clarion-Clipperton Zone (CCZ), a polymetallic nodule province, in the NE Pacific Ocean, where experimental mining is due to take place. In anticipation of deep-sea mining impacts, it has become essential to rapidly and accurately assess biodiversity. For this reason, ophiuroid material collected during seven scientific cruises from five exploration license areas within CCZ, one area protected from mining (APEI3, Area of Particular Environmental Interest) in the periphery of CCZ and the DIS-turbance and re-COLonisation (DISCOL) Experimental Area (DEA), in the SE Pacific Ocean, was examined. Specimens were genetically analysed using a fragment of the mitochondrial cytochrome c oxidase subunit I (COI). Maximum Likelihood and Neighbour Joining trees were constructed, while four tree-based and distance-based methods of species delineation (ABGD, BINs, GMYC, mPTP) were employed to propose Secondary Species Hypotheses (SSHs) within the ophiuroids collected. The species delimitations analyses concordant results revealed the presence of 43 deep-sea brittle stars SSHs, revealing an unexpectedly high diversity and showing that the most conspicuous invertebrates in abyssal plains have been so far considerably under-estimated. The number of SSHs found in each area varied from 5 (IFREMER area) to 24 (BGR area), while 13 SSHs were represented by singletons. None of the SSHs was found to be present in all 7 areas, while the majority of species (44.2 %) had a single-area presence (19 SSHs). The most common species were Ophioleucidae sp. (Species 29), Amphioplus daleus (Species 2) and Ophiosphalma glabrum (Species 3), present in all areas except APEI3. The biodiversity patterns could be mainly attributed to POC fluxes that could explain the highest species numbers found in BGR (German contractor area) and UKSRL (UK contractor area) areas. The five exploration contract areas belong to a mesotrophic province, while in contrary the APEI3 is located in an oligotrophic province which could explain the lowest diversity as well as very low similarity with the other six study areas. Based on these results the representativeness and the appropriateness of APEI3 to meet its purpose of preserving the biodiversity of the CCZ fauna are questioned. Finally, this study provides the foundation for biogeographic and functional analyses that will provide insight into the drivers of species diversity and its role in ecosystem function

Bioregions in marine environments: Combining Biological and Environmental Data for Management and Scientific Understanding

Bioregions are important tools for understanding and managing natural resources. Bioregions should describe locations of relatively homogenous assemblages of species occur, enabling managers to better regulate activities that might affect these assemblages. Many existing bioregionalization approaches, which rely on expert-derived, Delphic comparisons or environmental surrogates, do not explicitly include observed biological data in such analyses. We highlight that, for bioregionalizations to be useful and reliable for systems scientists and managers, the bioregionalizations need to be based on biological data; to include an easily understood assessment of uncertainty, preferably in a spatial format matching the bioregions; and to be scientifically transparent and reproducible. Statistical models provide a scientifically robust, transparent, and interpretable approach for ensuring that bioregions are formed on the basis of observed biological and physical data. Using statistically derived bioregions provides a repeatable framework for the spatial representation of biodiversity at multiple spatial scales. This results in better-informed management decisions and biodiversity conservation outcomes.Peer reviewe

The diverse and widespread Southern Ocean ophiuroid Amphiura belgicae should be considered a species complex

Accurate knowledge of geographic ranges of species is essential for effective conservation management. Species with large distributions and good connectivity are presumed to be resilient to adverse localised/regional conditions, whereas those with small ranges and, thus, smaller population sizes are more likely to be vulnerable. The rich benthic assemblages across the Southern Ocean are generally considered 'Antarctic' with some input from South America contributing to diversity on the sub-Antarctic island shelves. However, molecular work over the past two decades is challenging the paradigm of a general Antarctic benthic fauna, with evidence mounting for assemblages being regionally unique in terms of genetic diversity, regardless of formal taxonomic species composition. The widely distributed brittle star, Amphiura belgicae, is one element of the Southern Ocean benthic assemblage that has a complex historical taxonomic background hinting that it may in reality be a complex of species, each with small geographic range and little connectivity. Our study identified deep genetic divisions between geographically isolated populations, particularly between those on the Patagonian shelf, and elsewhere. Indeed, populations on the Patagonian shelf were more closely related to the sympatric sister species A. eugeniae than to any other Southern Ocean population. We compare our data with a study of Ophiuroglypha lymani from similar collections, highlighting that both show highly regionalized populations, particularly on Island shelves, and both share the curious phenomenon of a presumed outgroup species being an element of the ingroup. We suggest that the isolated populations of both these species are following distinct evolutionary and ecological trajectories and that both should be treated as species complexes

The antioxidant and chemopreventive potentialities of Mosidae (Adenophora remotiflora) leaves

Our study focused on the antioxidant activities of Mosidae leaf ethanol extract (MLE) and included measurements of reducing power, total phenolic compounds, DPPH radical scavenging activity, and hydroxyl radical scavenging activity. In order to determine whether or not MLE evidences any chemopreventive activities, experimental lung metastasis was induced via the i.v. inoculation of colon26-M3.1 carcinoma cells into BALB/c mice. Additionally, we attempted to characterize any possible cytotoxic effects in murine normal splenocytes and tumor cells (B16-BL6 and colon26-M3.1). The total phenolic content and reducing capacity were measured at 39 mg/100 mL and 1.24, respectively, whereas the DPPH and hydroxyl radical scavenging activities of MLE were measured to be 88.89% and 22.10%, respectively. Prophylactic i.v. treatment with MLE resulted in a dose-dependent and significant inhibition of lung metastasis. Specifically, a MLE dose of 200 ug per mouse resulted in an 88.90% inhibition of lung metastasis. For the cytotoxicity assay, MLE doses up to 100 ug/mL were not shown to affect the growth of normal murine splenocytes. Additionally, the survival of normal cells was not affected at MLE doses below 500 ug/mL. However, MLE doses up to 500 ug/mL reduced the percentage of tumor cell growth for B16BL6 (67% alive) and colon26-M3.1 (62% alive) cells

Global Diversity of Brittle Stars (Echinodermata: Ophiuroidea)

This review presents a comprehensive overview of the current status regarding the global diversity of the echinoderm class Ophiuroidea, focussing on taxonomy and distribution patterns, with brief introduction to their anatomy, biology, phylogeny, and palaeontological history. A glossary of terms is provided. Species names and taxonomic decisions have been extracted from the literature and compiled in The World Ophiuroidea Database, part of the World Register of Marine Species (WoRMS). Ophiuroidea, with 2064 known species, are the largest class of Echinodermata. A table presents 16 families with numbers of genera and species. The largest are Amphiuridae (467), Ophiuridae (344 species) and Ophiacanthidae (319 species). A biogeographic analysis for all world oceans and all accepted species was performed, based on published distribution records. Approximately similar numbers of species were recorded from the shelf (n = 1313) and bathyal depth strata (1297). The Indo-Pacific region had the highest species richness overall (825 species) and at all depths. Adjacent regions were also relatively species rich, including the North Pacific (398), South Pacific (355) and Indian (316) due to the presence of many Indo-Pacific species that partially extended into these regions. A secondary region of enhanced species richness was found in the West Atlantic (335). Regions of relatively low species richness include the Arctic (73 species), East Atlantic (118), South America (124) and Antarctic (126)