02229nas a2200181   4500008004100000020001400041245014200055210006900197260000800266300001400274490000700288520163400295100001901929700002101948700001401969700001801983856004602001       2009                        eng d  a0025-315400aA morphometric analysis of the genus <i>Terschellingia</i> (Nematoda: Linhomoeidae) with redefinition of the genus and key to the species0 amorphometric analysis of the genus iTerschellingiai Nematoda Lin  cSep  a1257-12670 v893 aThe cosmopolitan and often ecologically dominant genus Terschellingia (Nematoda: Linhomoeidae), with 38 nominal species, is taxonomically a problematic taxon. Its species show high morphological plasticity, possess few diagnostic characters and identification keys are lacking. A revision of the genus was carried out based on morphological and morphometric data from the literature and from observations of specimens collected in Cienfuegos Bay, Caribbean Sea, Cuba. The diagnosis of the genus Terschellingia is emended. Of the current 38 nominal species, 15 are considered as valid species based on morphological characters related to size and position Of amphidial fovea, presence/position of cephalic and cervical setae, presence/size/shape of pharyngeal bulb, shape of spicular apparatus and shape of tail. Tabular and pictorial keys were provided based on these characters. Three sympatric species: T. communis, T. gourbaultae and T. longicaudata were redescribed based on recently collected Cuban specimens. Each of them showed relatively large differences in body size in comparison with the respective type specimens, suggesting possible variation due to local environmental differences. The highest intraspecific variation pertains for the most widely spread cosmopolitan species T. longicaudata, suggesting that morphological plasticity enhanced adaptation to different environmental conditions. The notable taxonomic inflation within the genus (14 species inquirendae, 9 junior synonyms), probably also present in other highly specious genera of marine nematodes, can lead to an overestimation of the alpha-diversity.1 aArmenteros, M.1 aRuiz-Abierno, A.1 aVincx, M.1 aDecraemer, W.  uhttps://nematodes.myspecies.info/node/13002806nas a2200217   4500008004100000020001400041245010300055210006900158260000800227300001200235490000700247520214500254100001902399700002102418700002502439700002502464700002102489700001402510700001802524856004602542       2009                        eng d  a0272-771400aBiodiversity patterns of free-living marine nematodes in a tropical bay: Cienfuegos, Caribbean Sea0 aBiodiversity patterns of freeliving marine nematodes in a tropic  cNov  a179-1890 v853 aSpatial and temporal biodiversity patterns of free-living marine nematodes were studied in Cienfuegos Bay, a tropical semi-enclosed basin in the Caribbean Sea. Taxonomic (to species level) and functional (biological trait) approaches were applied for describing the assemblage structure and relating it to abiotic environment based on a sampling scheme in six subtidal stations and three months. Biological trait approach added relevant information to species pattern regarding relationships between diversity patterns and the abiotic environment. The most common morphotypes were deposit feeding nematodes, with colonising abilities of 2-3 (in a scale from 1 to 5), tail conical cylindrical or filiforme and body slender; and their abundance were correlated with depth, organic matter and silt/clay fraction. In spite of a high turnover of species, functional diversity of assemblages did not change notably in space and time. A result probably due to sampling of the habitat pool of species and to low heterogeneity of the studied muddy bottoms. Chemical pollution (organic enrichment and heavy metals) and hydrodynamic regime possibly drove the biodiversity patterns. Spatial distribution of assemblages support the existence of two well differentiated basins inside the bay, the northern basin more polluted than the southern one. The low hydrodynamic regime would determine a poor dispersion of nematodes resulting in high spatial variance in the assemblage structure; and also the associated hypoxic conditions and pollutants in sediments can explain the dominance of tolerant nematode species such as Daptonema oxycerca, Sabatieria pulchra, Terschellingia gourbaultae, and Terschellingia longicaudata. A comparison of spatial-temporal patterns of biodiversity between Cienfuegos Bay and other semi-enclosed bays in temperate regions suggests several similarities: nematode assemblages are strongly influenced by anthropogenic disturbance, temporal trends are weak or overridden by spatial ones, and few cosmopolitan genera/species tolerant to pollution and hypoxic conditions are dominant. (C) 2009 Elsevier Ltd. All rights reserved.1 aArmenteros, M.1 aRuiz-Abierno, A.1 aFernandez-Garces, R.1 aPerez-Garcia, J., A.1 aDiaz-Asencio, L.1 aVincx, M.1 aDecraemer, W.  uhttps://nematodes.myspecies.info/node/13101657nas a2200217   4500008004100000020001400041245008400055210006900139260000800208300001200216490000700228520102300235100001901258700002501277700002101302700002101323700001701344700001401361700001801375856004601393       2010                        eng d  a0141-113600aEffects of organic enrichment on nematode assemblages in a microcosm experiment0 aEffects of organic enrichment on nematode assemblages in a micro  cDec  a374-3820 v703 aMarine nematodes from subtidal tropical sediments of Cienfuegos Bay were subjected to organic enrichment in a microcosm experiment for 32 days Nematode abundance and diversity decreased and the taxonomic and trophic structure was altered The results suggested that the nematodes were not food limited in the microcosms or in their natural environment. Chemical stressors such as ammonia and hydrogen sulfide derived from reduced conditions in sediments may be Important factors affecting the assemblages Hypoxic conditions occurred in all experimental units as well as in the field suggesting a nematode assemblage adapted to naturally enriched sediments However tolerant species showed a grade of sensitivity to reduced conditions In agreement with the model by Pearson and Rosenberg (1978) we predict that further organic enrichment in sediments from Cienfuegos Bay may cause a phase shift Into a strongly depleted benthic fauna and reduced conditions in water and sediments (c) 2010 Elsevier Ltd All rights reserved1 aArmenteros, M.1 aPerez-Garcia, J., A.1 aRuiz-Abierno, A.1 aDiaz-Asencio, L.1 aHelguera, Y.1 aVincx, M.1 aDecraemer, W.  uhttps://nematodes.myspecies.info/node/105