Phylum Ectoprocta, also known as bryozoans or moss animals, is a taxonomic group of small, aquatic invertebrates that belong to the larger animal kingdom, specifically the subkingdom Eumetazoa. They are known for their distinctive feature of forming complex, colony-like structures called zooids. Ectoprocts can be found in marine, freshwater, and even terrestrial habitats across the globe.
The word "ectoprocta" is derived from the Greek terms "ektos," meaning outside, and "proktos," meaning anus. This name refers to their unique anatomical feature of having a digestive system with the anus located outside the body, at the base of a tentacle specialized for waste elimination.
Ectoprocts are filter feeders, using their lophophore – a ring of ciliated tentacles - to capture small particles and microorganisms from the surrounding water. Each individual zooid within the colony has a hard exoskeleton, typically calcified, which provides protection and support. The colonies can take on various shapes and sizes, ranging from encrusting mats to tree-like structures.
The phylum Ectoprocta is said to have more than 6,000 known species, displaying a wide array of forms and adaptations. Their evolutionary history dates back to the Early Ordovician period, over 480 million years ago. They play important ecological roles, serving as both habitat-forming organisms and food sources for various marine organisms.
In summary, the phylum Ectoprocta comprises small, colonial invertebrates characterized by their external anus, filter-feeding abilities, and complex, calcified structures. They serve as valuable members of aquatic ecosystems and contribute significantly to the diversity of life on Earth.
