Lophophore
Encyclopedia
Bryozoa
The Bryozoa, also known as Ectoprocta or commonly as moss animals, are a phylum of aquatic invertebrate animals. Typically about long, they are filter feeders that sieve food particles out of the water using a retractable lophophore, a "crown" of tentacles lined with cilia...
, Entoprocta
Entoprocta
Entoprocta, whose name means "anus inside", is a phylum of mostly sessile aquatic animals, ranging from long. Mature individuals are goblet-shaped, on relatively long stalks. They have a "crown" of solid tentacles whose cilia generate water currents that draw food particles towards the mouth, and...
, and Phoronida. All lophophores are found in aquatic organisms.
Characteristics
It can most easily be described as a ring of ciliated tentacles surrounding the mouth, but it is often horseshoe-shaped or coiled. Phoronids have their lophophores in plain view, but the valves of brachiopods must be opened wide to get a good view of their lophophore.The lophophore surrounds the mouth and is an upstream collecting system for suspension feeding. Its tentacles are hollow with extensions of a coelomic
Body cavity
By the broadest definition, a body cavity is any fluid-filled space in a multicellular organism. However, the term usually refers to the space located between an animal’s outer covering and the outer lining of the gut cavity, where internal organs develop...
space thought to be a mesocoel. The gut is U-shaped with the anterior mouth at the center of the lophophore. The anus
Anus
The anus is an opening at the opposite end of an animal's digestive tract from the mouth. Its function is to control the expulsion of feces, unwanted semi-solid matter produced during digestion, which, depending on the type of animal, may be one or more of: matter which the animal cannot digest,...
, where present, is also anterior, but is dorsal to the mouth. In the Bryozoa
Bryozoa
The Bryozoa, also known as Ectoprocta or commonly as moss animals, are a phylum of aquatic invertebrate animals. Typically about long, they are filter feeders that sieve food particles out of the water using a retractable lophophore, a "crown" of tentacles lined with cilia...
it is outside the ring of the lophophore; in the Entoprocta
Entoprocta
Entoprocta, whose name means "anus inside", is a phylum of mostly sessile aquatic animals, ranging from long. Mature individuals are goblet-shaped, on relatively long stalks. They have a "crown" of solid tentacles whose cilia generate water currents that draw food particles towards the mouth, and...
the anus is within the ring of the lophophore. Some brachiopods do not have an anus.
Classification of lophophorates
Groups with lophophores are called lophophorates. In the old view of metazoan phylogeny, the lophophorates were placed within the Deuterostomia. Now they have been reassessed and placed within a new Superphylum known as the LophotrochozoaLophotrochozoa
The Lophotrochozoa are a major grouping of protostome animals. The taxon was discovered based on molecular data. Molecular evidence such as a result of studies of the evolution of small-subunit ribosomal RNA supports the monophyly of the phyla listed in the infobox shown at right.-Terminology:The...
(located within the Protostomia) which includes the Mollusca
Mollusca
The Mollusca , common name molluscs or mollusksSpelled mollusks in the USA, see reasons given in Rosenberg's ; for the spelling mollusc see the reasons given by , is a large phylum of invertebrate animals. There are around 85,000 recognized extant species of molluscs. Mollusca is the largest...
and Annelida.
The extinct hederelloids
Hederellid
Hederellids are extinct colonial animals with calcitic tubular branching exoskeletons. They range from the Silurian to the Permian and were most common in the Devonian period. They are more properly known as "hederelloids" because they were originally defined as a suborder by Bassler , who...
, microconchids
Microconchida
The Order Microconchida is a group of small, spirally-coiled, encrusting fossil "worm" tubes found from the Upper Ordovician to the Middle Jurassic around the world . They have lamellar calcitic shells, usually with pseudopunctae or punctae and a bulb-like origin...
, cornulitids and tentaculitids
Tentaculite
Tentaculites is an extinct genus of molluscs known from Devonian age fossils, ranging from 360-410 million years ago. The taxonomic classification of tentaculitids is uncertain, but some group them with pteropods. They may also be related to other conical shells of uncertain affinity including...
were likely lophophorates based on their biomineralization.