Chthamalidae
Chthamalidae is a family of barnacles within the infraorder Balanomorpha. They are commonly known as acorn barnacles because of their conical shape. These barnacles are found in intertidal and subtidal regions of the ocean, attached to hard substrates such as rocks, piers, and even the hulls of ships. Their distribution is global, spanning various regions including the Atlantic, Pacific, and Indian Oceans. Chthamalidae are important members of marine ecosystems, playing a role in both the food web and the biofouling of marine structures.
Characteristics
Chthamalidae are characterized by their conical, often ribbed shells, with an operculum composed of four valves that open and close for feeding and protection. They have a unique structure called the carina, a prominent ridge that runs along the center of the shell. They are also characterized by their feeding mechanisms, using their cirri, or feathery appendages, to filter food particles from the water.
Environments
Members of Chthamalidae are well-adapted to the harsh conditions of the intertidal zone, particularly those exposed to high levels of wave action and desiccation. They have developed mechanisms to withstand fluctuations in salinity, temperature, and oxygen levels. These adaptations include:
- A strong, protective shell
- The ability to close their operculum tightly to retain moisture during low tides
- The capacity to survive periods of oxygen deprivation
Some species, such as Chthamalus fragilis, are even capable of living in the subtidal zone, where they are permanently submerged.
References
For further information on Chthamalidae, consult the following reliable sources: