03969nas a2200217   4500008004100000245007600041210006900117260010400186300001200290490000700302520319100309653001703500653001403517653001403531653002103545653002003566653002003586653002103606100001503627856010903642       2006                        eng d00aPhylogeny of Taenia: Species definitions and origins of human parasites0 aPhylogeny of Taenia Species definitions and origins of human par  aELSEVIER HOUSE, BROOKVALE PLAZA, EAST PARK SHANNON, CO, CLARE, 00000, IRELANDbELSEVIER IRELAND LTD  aS23-S300 v553 aPhylogeny is fundamental as it constrains explanations about history and forms our foundation for recognizing and diagnosing species. In the absence of such a framework taxonomists historically relied on intuitive processes, personal judgment and authority, often embracing a typological view of species that disregarded otherwise unequivocal historical and biological criteria. Species of Taenia are among the most characteristic tapeworms infecting carnivores and humans as definitive hosts and indeed Taemidae is unique among the Eucestoda in requiring 2 obligate mammalian hosts for transmission; a high percentage (>80%) of life cycles have been completely elucidated among the approximately 45 species and nominal subspecies of Taenia. Until recently there had been no comprehensive attempts at reconstruction of a phylogeny among these important parasites. Such analyses have allowed us to explore the origins and evolution of those independent species of Taenia that occur in humans (T saginata, T asiatica, and T solium) and to understand the ecological and historical processes serving as determinants of biogeography and host-association. These studies supported the status of T asiatica as a valid species and diagnosed a relationship as the sister-species of T saginata. These conclusions contrasted with a diversity of opinions that would subsume T asiatica as a subspecies. Recognition of a species constitutes a specific and testable hypothesis, is not an arbitrary decision and is most appropriately assessed in the context of phylogenetic or historical data. Considering macrospecies, a process has been outlined by Brooks and McLennan [Brooks DR, McLennan DA. The nature of diversity: an evolutionary voyage of discovery. University of Chicago Press: Chicago; 2002] as follows: (1) Discovery: a systematist describes the species; (2) Phylogenetic reconstruction; (3) Evaluation I: do sister-species show geographical overlap-are they sympatric or allopatric (use phylogeny+geographical distributions)? (4) Evaluation II: are sister-species reproductively isolated based on information from natural history, ecology and reproductive biology? Species may be viewed in the context of microevolutionary and macroevolutionary processes. For instance, microspecies are defined in ecological time and involve populations and contemporary process that are potentially reversible (reticulate). In contrast, macrospecies as exemplified by T saginata and T asiatica are divergent lineages resulting from processes in evolutionary time where an ancestor has undergone a permanent split that is non-reversible (non-reticulate). Applying these criteria in evaluation of T saginata and T asiatica, it becomes clear that in evolutionary time these represent historical lineages with independent spatial and temporal trajectories, having separated from a common ancestor near 0.78 to 1.71 MYBP in Africa, or Eurasia. In ecological time, sympatry, reproductive isolation, and differences in life history evident for T saginata and T asiatica as observed in China, and perhaps other regions of Southeast Asia, further serve to validate these taeniids. Published by Elsevier Ireland Ltd.10abiogeography10aevolution10aphylogeny10aspecies concepts10aTaenia asiatica10aTaenia saginata10aTaenia tapeworms1 aHoberg, EP  uhttps://nematoda.myspecies.info/content/phylogeny-taenia-species-definitions-and-origins-human-parasites02499nas a2200217   4500008004100000245007000041210006900111260005200180300001400232490000700246520176100253653001902014653002602033653001702059653001302076653002702089653002202116100002102138700002202159856010002181       2009                        eng d00aRegional patterns of nematode assemblages in the Arctic deep seas0 aRegional patterns of nematode assemblages in the Arctic deep sea  a233 SPRING ST, NEW YORK, NY 10013 USAbSPRINGER  a1345-13570 v323 aSurface primary productivity and carbon flux in the Arctic Seas are higher along the warm Spitsbergen Water Current than along the ice-infested East Greenland Current. These contrasting oceanographic conditions are reflected in the deep-sea environment and may shape nematode assemblages. However, the paucity of samples in the Arctic deep seas precludes any regional scale assessment. In the present study, nematode assemblages were investigated in relation to a range of environmental variables along the 2,000 m isobath between latitudes 72A degrees N and 79A degrees N for both East and Western margins of the northern North Atlantic. Results showed that both margins had distinct environmental characteristics, with respect to chloroplastic pigments, sediment water content, sediment-bound organic matter, phospholipids and particulate proteins. Nematode assemblages varied according to these environmental changes. Along the more oligotrophic western margin, chloroplastic pigments increased towards the North, while the other environmental variables, nematode abundances and species richness decreased. In contrast, along the eastern margin, we observed higher quantities of organic matter and particulate protein, which supported higher abundance and species richness. Nematode assemblages along both margins varied according to food availability with species composition more variable in areas with lower amounts. Seventy percent of the species occurred in both margins indicating a low turnover of species. The present results support the hypothesis of a positive latitudinal gradient across the North Atlantic and further suggest that contemporary climate and recent ecological processes may predict nematode diversity patterns at larger scales.10aArctic benthos10aArctic marine ecology10abiogeography10adeep sea10aLatitudinal variations10aspecies diversity1 aFonseca, Gustavo1 aSoltwedel, Thomas  uhttps://nematoda.myspecies.info/content/regional-patterns-nematode-assemblages-arctic-deep-seas02310nas a2200229   4500008004100000245010800041210006900149260007600218300001200294490000700306520144500313653002601758653001701784653001601801653001901817653002401836653002501860100002101885700002401906700001901930856013101949       2007                        eng d00aSpecies richness of the genus Molgolaimus (Nematoda) from local to ocean scale along continental slopes0 aSpecies richness of the genus Molgolaimus Nematoda from local to  a9600 GARSINGTON RD, OXFORD OX4 2DQ, OXON, ENGLANDbBLACKWELL PUBLISHING  a446-4590 v283 aThis study investigated the distribution of Molgolaimus species (Nematoda) at different hierarchical spatial scales and observed the turnover of species along bathymetrical transects and among transects in two separate geographical regions. Samples from six transects (200-2000 m) from the Southern Oceans (SO) and four bathymetric transects (50-2000 m) from the Western Indian Ocean (WIO) were compared. Of the 30 species recorded, only one was common to both regions. WIO had higher local species richness than the SO. In both regions, the local scale was the greatest contributor to the total species richness. In the SO, there was no difference between species turnover at the different spatial scales, however, in the WIO, the turnover along bathymetrical transects was higher than among separated transects. For the particular genus studied, the evidence suggests that the study area in WIO has more widespread species and was better sampled, while the SO has many restricted species and it is most probably characterized by different biogeographical provinces. At the ocean scale (i.e. WIO versus SO), evolutionary histories may have strongly influenced nematodes species composition, while at local and regional scales, ecological processes are probably promoting species co-existence and speciation. The high co-existence of certain species at local scale is partially explained by species preference for different sediment layers.10aadditive partitioning10abiogeography10aocean floor10aSouthern Ocean10aturnover of species10aWestern Indian Ocean1 aFonseca, Gustavo1 aMuthumbi, Agnes, W.1 aVanreusel, Ann  uhttps://nematoda.myspecies.info/content/species-richness-genus-molgolaimus-nematoda-local-ocean-scale-along-continental-slopes