Apodida
Apodida is an order of sea cucumbers, commonly known as apodids or snake cucumbers. They are characterized by their elongated, worm-like bodies, lacking any appendages or arms. Unlike other sea cucumbers, apodids lack tube feet and have a reduced or absent calcareous ring. This order is comprised of over 200 species distributed worldwide in various marine environments.
Characteristics
Apodids typically have a smooth, cylindrical body that can be quite long, reaching lengths of up to 3 meters in some species. They lack the typical radial symmetry of other sea cucumbers, instead possessing bilateral symmetry. Their skin is often leathery and covered in small, scattered ossicles, which are tiny, calcareous plates. Apodids have a mouth at one end and an anus at the other.
Due to their lack of tube feet, apodids rely on their muscular bodies for locomotion. They burrow through sediment or crawl along the seabed, using their mouth to ingest food. Many apodids are deposit feeders, consuming sediment and extracting organic matter. Others are carnivorous, feeding on small invertebrates.
Environments
Apodids can be found in a variety of marine habitats, including:
- Shallow coastal waters
- Deep-sea trenches
- Coral reefs
- Seagrass meadows
They are often found in soft sediments, where they can burrow and hide from predators.
References
For further information on Apodida, consult the following resources: