Sublittoral Meiofauna and Diversity of Nematode Assemblages off Guadeloupe Islands (French West Indies)

Sublittoral meiofauna were studied at 12 shallow stations from Guadeloupe and its satellite islands (French West Indies). Meiofauna densities (2,260 ± 658 ind˙10 cm^–2) were higher than previous records from the Caribbean basin, but in the same range as other records from tropical environments. Nematodes represented 79.4 ± 4.5% of the total meiofaunal individuals. Multivariate analysis and hierarchical analysis allowed interstation comparisons and demonstrated that species composition was related to oxygenation conditions of the sediment. The redox-potential discontinuity level together with organic content, silt fraction of sediments and/or hydrodynamic conditions were identified as the factors regulating the species assemblages. Desmodoridae was the most abundant and diverse family at most of the stations. Average diversity values were significantly higher in total cores (0–12 cm): SR = 5.43 ± 0.42 (12): H′ = 3.75 ± 0.18; J′ = 0.79 ± 0.03, than in surface sediment (0–4 cm). The number of species per family increased from fine to coarse sand, but no correlation occurred between species diversity and median grain size or silt content, suggesting that oxygen depletion is a significant factor affecting nematode species assemblages at these sites.