Scanning electron microscopy in the taxonomical study of free-living marine nematodes

Free-living marine nematodes are microinvertebrates composing one of the most diversified groups of the marine biota, with more than 7000 species. This means that only the 20% of the species is currently known. Several morphological features can help their taxonomical identification such as cephalic, cervical and body setae, amphids, cuticle, spicules and tail that may also have a functional role. Given the small size of these organisms, they differ in minute characters that can be detected more effectively by scanning electron microscopy (SEM). This study presents an overview of the use of SEM on some nematode species collected in the Maldivian archipelago, and highlights the importance of this technique in the taxonomical study of nematodes as well as its potentialities in the functional investigation of some of their structures.