Desmoscolecids
Desmoscolecids are a family of free-living marine nematodes, commonly known as armored or spiny nematodes. They are characterized by their distinctive cuticular annulation, meaning their outer layer is segmented into rings, often bearing spines, tubercles, or other elaborate structures. This ornamentation gives them a superficially segmented appearance, distinguishing them from other nematode groups. Desmoscolecids inhabit a wide range of marine environments, from shallow coastal sediments to deep-sea trenches, and are found in both tropical and temperate waters. They are typically deposit feeders, ingesting sediment and extracting organic matter, and play a role in benthic ecosystems. Their unique morphology has made them a subject of interest in evolutionary biology and paleontology, as some fossil forms exhibit similar features. While microscopic, their abundance in certain sediments can be significant. Research on desmoscolecids continues to expand our understanding of marine nematode diversity and the ecological roles of these fascinating creatures.