@article {5927, title = {Selectivity on epilithic diatom consumption for two tropical sympatric gobies: Sicydium punctatum (Perugia 1986) and Sicydium plumieri (Bloch 1786)}, journal = {Cybium }, volume = {42 }, year = {2018}, pages = {365-373}, abstract = {

\ Rivers of the Caribbean islands harbour a freshwater fauna mainly constituted of migrant diadromous species. In these hyperturbulent ecosystems, the primary producers are mostly represented by a thin epilithic biofilm, mainly composed of diatoms. Comparison of the diatoms available from the environment with the ones consumed and located in the digestive tracts of two gobiid fish, Sicydium punctatum Perugia, 1896 and Sicydium plumieri (Bloch, 1786) were made at twelve sampling locations, located upstream or downstream of six rivers, in Guadeloupe. One hundred and ninety-one epilithic diatom species were identified. A statistical approach was used to determine diatoms that best characterize the two species digestive tracts content (i.e. {\textquotedblleft}diagnostic species{\textquotedblright}) and to evaluate the statistical relationship between species abundances and groups of sites or conditions. Eight taxa belonging to five families were considered as significant diagnostic species of digestive tracts from fish collected upstream (Achnanthidium subhudsonis, Achnanthes rupestoides, Diadesmis contenta, Diadesmis sp., Eolimna sp., Navicula (dicta) seminulum, Navicula difficillima and Nupela sp.), and five taxa belonging to three families were considered as significant diagnostic species for fish collected downstream (Gomphonema parvulum, Navicula arvensis, Navicula cruxmeridionalis, Nitzschia frustulum and Navicula incarum). Results indicate selective consumption of epilithic diatoms by the two major fish observed in the mid and upper stream of Caribbean rivers

}, keywords = {Biofilm, Bioindication, Caribbean Islands, Gobiidae, Tropical rivers}, author = {Monti, Dominique and Lefran{\c c}ois, F and Clara Lord and Jean-Michel Mortillaro and Pascal Jean Lopez and Philippe Keith} } @article {4176, title = {Spatial and seasonal contrasts of sedimentary organic matter in floodplain lakes of the central Amazon basin}, journal = {Biogeosciences}, volume = {13}, year = {2016}, type = {original}, abstract = {


In this study, we investigated the seasonal and spatial pattern of sedimentary organic matter (SOM) in five floodplain lakes of the central Amazon basin (Cabaliana, Janauaca, Cana{\c c}ari, Mirituba and Curuai) which have different morphologies, hydrodynamics and vegetation coverages. Surface sediments were collected in four hydrological seasons: low water (LW), rising water (RW), high water (HW) and falling water (FW) in 2009 and 2010. We inves-tigated commonly used bulk geochemical tracers such as the C/N ratio and the stable isotopic composition of organic carbon (13Cor). These results were compared with lignin phenol parameters as an indicator of vascular plant detritus and branched glycerol dialkyl glycerol tetraethers (brGDGTs) to trace the input of soil organic matter (OM) from land to the aquatic settings. We also applied the crenarchaeol as an indi- cator of aquatic (rivers and lakes) OM. Our data showed that during the RW and FW seasons, the surface sediments were enriched in lignin and brGDGTs in comparison to other seasons. Our study also indicated that floodplain lake sediments primarily consisted of allochthonous, C3 plant-derived OM. However, a downstream increase in C4 macrophyte-derivedOM contribution was observed along the gradient of increas-ing open waters {\textendash} i.e., from upstream to downstream. Accordingly, we attribute the temporal and spatial difference in SOM composition to the hydrological dynamics between the floodplain lakes and the surrounding flooded forests.

}, author = {Sobrinho, R L and Bernardes, Marcelo C and Gwena{\"e}l Abril and Kim, J-H and Zell, C and Jean-Michel Mortillaro and Tarik Meziane and Moreira-Turcq, P and J S Sinningh Damst{\'e}} }