Amphiuridae
Amphiuridae is a family of brittle stars within the class Ophiuroidea, which belong to the phylum Echinodermata. These creatures are commonly known as brittle stars, serpent stars, or sand stars due to their unique physical characteristics and movement patterns.
Characteristics
Members of the Amphiuridae family share several distinctive traits. They possess a central disc-shaped body with five long, slender arms that are easily detached, hence the name "brittle star." These arms are covered in tiny, overlapping scales and are flexible, allowing them to move quickly and gracefully across the seafloor. Unlike other echinoderms, Amphiuridae have a distinct skeletal structure, with a series of ossicles or bony plates that provide support and flexibility to the arms.
Amphiuridae also exhibit a distinctive feeding mechanism. They are deposit feeders, meaning they scavenge for food in the sediment, relying on their sensitive tube feet to sense and gather organic debris. Their mouths are located on the underside of the central disc and are surrounded by five jaws.
Environments
Amphiuridae can be found in a variety of marine environments, from shallow coastal waters to the deep sea. They are particularly abundant in soft-bottom habitats, such as sand, mud, and gravel, where they can burrow and forage for food. Some species are also found in association with coral reefs and other hard-bottom communities.
Distribution
Amphiuridae have a cosmopolitan distribution, meaning they are found in all the world's oceans. Their geographic range extends from the tropics to the polar regions, with a wide variety of species inhabiting different depths and ecosystems.
Notable Genera
The Amphiuridae family includes several notable genera, each with its own unique characteristics and ecological role:
- Amphiura: The largest genus in the family, with over 200 described species. These brittle stars are typically found in shallow waters and are known for their slender arms and rapid movements.
- Ophiophragmus: This genus is characterized by its short, stout arms and its ability to burrow into soft sediments. They are often found in association with seagrass beds.
- Ophiocoma: These brittle stars are known for their bright, colorful arms and their ability to regenerate lost limbs. They are common inhabitants of coral reefs.
- Ophiopsila: This genus includes brittle stars with long, slender arms that are often covered in spines. They are typically found in deeper waters.