Marine Nematodes from the Shallow Subtidal Coast of the Adriatic Sea: Species List and Distribution

This study is the first attempt aiming to assess the composition and number of free-living marine nematode species on the coasts of Marches region, Italy. A high number of putative species of nematodes was recognized (84), these belonging to 52 genera in 22 families. Fifty-one taxa have been identified to species level increasing the number of known nematode species for the Adriatic Sea from 283 to 310 and Mediterranean Sea from 700 to 723. The highest diversity and abundance were registered for the nematode families typically of intertidal zones characterized as medium-fine sands. The majority of the species found in the present study are known to occur in the North European coasts or the North Atlantic Sea, the best known regions for nematode distribution. Inferences on the biogeography of marine nematodes are preliminary since most biodiversity literature concerning the Mediterranean basin is very out of date. Considering the great importance of nematodes in the assessment of ecosystem health conditions, an intensification of sampling efforts should be pursued in other regions in order to improve our current knowledge on the distribution pattern of marine nematode species as well as clarify their biogeographical patterns.