01803nas a2200169   4500008004100000020001400041245013800055210006900193260000800262300001000270490000700280520124800287100001601535700001801551700001801569856004601587       2006                        eng d  a0954-102000aTaxonomy and biogeography of Molgolaimus Ditlevsen, 1921 (Nematoda : Chromadoria) with reference to the origins of deep sea nematodes0 aTaxonomy and biogeography of Molgolaimus Ditlevsen 1921 Nematoda  cMar  a23-500 v183 aMolgolaimus is a genus of free-living marine nematodes which is found in high densities (10-35% of the total community) LIP to 2000 in depth. Its occurrence is often associated with organically enriched and recently disturbed areas. Currently, only 16 species have been described, mainly from shallow waters. The present study contributes 17 new species mainly from the Weddell Sea but also from the Pacific Ocean, and provides an illustrated polytomous identification key to species level. The 33 Molgolaimus species described can be identified based on just a few morphometric features: spicule length, body length, anal body diameter, tail length and pharynx length. A first insight into the biogeography of this deep sea genus at species level is presented. A comparison of morphometric characteristics between species suggests that the most similar species co-occur in the same geographical region, rather than within the same bathymetric zones or similar ecosystems separated over long distances. These observations suggest that deep sea nematodes may not have a common origin but might have derived "recently" from shallow water taxa. Therefore, global distribution of nematodes could be explained by means of palacogeographical events.1 aFonseca, G.1 aVanreusel, A.1 aDecraemer, W.  uhttps://nematodes.myspecies.info/node/15401709nas a2200157   4500008004100000020001400041245010200055210006900157300001200226490000700238520120800245100001601453700001801469700001801487856004601505       2006                        eng d  a0007-972300aTaxonomy and species distribution of the genus Manganonema Bussau, 1993 (Nematoda : Monhysterida)0 aTaxonomy and species distribution of the genus Manganonema Bussa  a189-2030 v473 aDifferent deep-sea sites are frequently characterized by a high number of species belonging to the same genus. In addition, some deep-sea genera (e.g. Acantholaimus, Monhystera, Halalaimus) seem to be dominant and present worldwide. The genus Manganonema is present in all oceans in low to medium densities (< 2%) and, apparently, restricted to the deep sea (600 m and deeper). The present study deals with a revision of the genus Manganonema based upon known species and nine new species, where only 5 were named due to the lack of males (M. media sp. nov., M. pitilica sp. nov., M. robustus sp. nov., M. antarctica sp. nov., M. bussauensis sp. nov.). For the species identification, important characters are summarized in a pictorial key. The material studied was collected from six different sites: two in the North Atlantic (Europe), two in the Southern Ocean (Antarctic), one in the South-western Atlantic (Brazil), and one in Western Indian Ocean (Kenya). The species distribution suggests a high turnover of species between sites. Only one Manganonema species is recorded from two different sites in the Atlantic Ocean. These results suggest a high degree of endemism of species within the genus.1 aFonseca, G.1 aDecraemer, W.1 aVanreusel, A.  uhttps://nematodes.myspecies.info/node/15501400nas a2200157   4500008004100000020001400041245007200055210006900127260000800196300001400204490000700218520093700225100001601162700001801178856004601196       2008                        eng d  a0025-315400aState of the art of the free-living marine Monhysteridae (Nematoda)0 aState of the art of the freeliving marine Monhysteridae Nematoda  cNov  a1371-13900 v883 aThe family Monhysteridae is characterized by 17 valid genera, seven of which are known to be free-living, inhabiting marine sediments. In total, 70 valid marine species are ascribed to these seven genera. Overall, the family is characterized by a confused taxonomic history with a large list of synonyms and species inquirendae. The taxonomic problem is not restricted to the old literature, but inconsistencies also appeared in recent studies. The aim of this study is to show the most important diagnostic characters to identify each genus and provide taxonomic tools for species identification. Dichotomous-keys and illustration-guides are attempted for the marine monhysterid species. For the family and each subfamily, tribe and marine genus a brief historical background, diagnosis and a list Of valid species is provided. Hereby, we propose to transfer eight species of the genus Thalassomonhystera to the genus Monhystrella.1 aFonseca, G.1 aDecraemer, W.  uhttps://nematodes.myspecies.info/node/137