Poecilasmatidae
Poecilasmatidae is a family of barnacles in the infraorder Balanomorpha. They are commonly known as “stalkless barnacles” or “acorn barnacles.” These small crustaceans are characterized by their conical or cylindrical shells, which are typically attached to hard surfaces in marine environments. They are found in a wide range of habitats, from the intertidal zone to deep sea environments.
Characteristics
Poecilasmatidae barnacles possess several distinct characteristics that distinguish them from other barnacle families:
- Stalkless: They lack a stalk, unlike other barnacles like the goose barnacles.
- Conical or cylindrical shells: Their shells are usually conical or cylindrical, with a distinct opening at the top.
- Six plates: The shell is composed of six overlapping plates, which are arranged in a specific pattern.
- Operculum: The opening of the shell is closed by a pair of movable plates called an operculum.
- Cirri: They have six pairs of feathery appendages called cirri, which they use to filter food from the water.
Environments
Poecilasmatidae barnacles are found in a variety of marine environments, including:
- Intertidal zone: They are common inhabitants of rocky shores and tide pools.
- Subtidal zone: They can also be found in deeper waters, attached to various substrates like kelp, seagrass, and marine debris.
- Deep sea: Some species are adapted to live in the abyssal depths of the ocean.
References
For more information on Poecilasmatidae, refer to the following reliable sources: