Amphilepidida

Common Names

Members of the order Amphilepidida are commonly known as "scale worms" due to the presence of scales on their bodies. These scales, which are modified setae, serve a variety of functions, including protection, locomotion, and sensory perception.

Characteristics

Amphilepidid worms possess several defining characteristics, including:

• Scales: The most prominent feature of Amphilepidida is the presence of scales, which are modified setae found on their bodies. These scales can vary in size, shape, and arrangement depending on the species.
• Body Shape: Amphilepidid worms are typically elongated and segmented, with a distinct head and a tail. They can range in size from a few millimeters to several centimeters in length.
• Parapodia: Like most polychaetes, Amphilepidid worms have parapodia, which are paired, fleshy appendages on each segment. These parapodia are used for locomotion and respiration.
• Proboscis: Amphilepidid worms possess a proboscis, a retractable, muscular organ that is used for feeding. The proboscis can be armed with teeth or hooks depending on the species.
• Sensory Structures: Amphilepidid worms have a variety of sensory structures, including eyes, palps, and antennae, which are used for detecting food, predators, and mates.

Environments

Amphilepidida are found in a wide range of marine environments, including:

• Shallow coastal areas: Some species are found in shallow waters, such as intertidal zones and rocky reefs.
• Deep-sea trenches: Other species live in the deep sea, where they can be found at depths of several thousand meters.
• Sedimentary environments: Many species of Amphilepidida burrow into sediments, where they feed on detritus or small invertebrates.

References

For further information on Amphilepidida, consult the following references:

• Wikipedia: Amphilepidida
• World Register of Marine Species: Amphilepidida
• PubMed: Search for "Amphilepidida"