Concept
Mollusca
Related concepts (116)
Ascidiacea
Ascidiacea, commonly known as the ascidians or sea squirts, is a paraphyletic class in the subphylum Tunicata of sac-like marine invertebrate filter feeders. Ascidians are characterized by a tough outer "tunic" made of a polysaccharide. Ascidians are found all over the world, usually in shallow water with salinities over 2.5%. While members of the Thaliacea (salps, doliolids and pyrosomes) and Appendicularia (larvaceans) swim freely like plankton, sea squirts are sessile animals after their larval phase: they then remain firmly attached to their substratum, such as rocks and shells.
Spondylus
Spondylus is a genus of bivalve molluscs, the only genus in the family Spondylidae. They are known in English as spiny oysters or thorny oysters (though they are not, in fact, true oysters). In addition to its significance in the pre-Columbian times, Spondylus crassiquama was also an important part of Aztec culture. Spondylus amongst Aztecs included: art, jewelry, statues, religious motifs, and at times currency. One example of Spondylus used in art is the double-headed serpent which can be seen amongst images on the right of the page.
Terrestrial mollusc
Terrestrial molluscs or land molluscs (mollusks) are an ecological group that includes all molluscs that live on land in contrast to freshwater and marine molluscs. They probably first occurred in the Carboniferous, arising from freshwater ones. This group includes land snails and land slugs. Loss of the shell has taken place many times in different groups that are not evolutionarily closely related, and land snails and slugs are most often treated together as a single group in specialized malacological literature.
Entoprocta
Entoprocta Entou'prQkt@ (inside rectum/anus), or Kamptozoa kaem(p)t@'zou@, 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 both the mouth and anus lie inside the "crown". The superficially similar Bryozoa (Ectoprocta) have the anus outside a "crown" of hollow tentacles.
Riftia pachyptila
Riftia pachyptila, commonly known as the giant tube worm and less commonly known as the giant beardworm, is a marine invertebrate in the phylum Annelida (formerly grouped in phylum Pogonophora and Vestimentifera) related to tube worms commonly found in the intertidal and pelagic zones. R. pachyptila lives on the floor of the Pacific Ocean near hydrothermal vents. The vents provide a natural ambient temperature in their environment ranging from 2 to 30 °C, and this organism can tolerate extremely high hydrogen sulfide levels.
Mantis shrimp
Mantis shrimp are carnivorous marine crustaceans of the order Stomatopoda (). Stomatopods branched off from other members of the class Malacostraca around 340 million years ago. Mantis shrimp typically grow to around in length, while a few can reach up to . A mantis shrimp's carapace (the hard, thick shell that covers crustaceans and some other species) covers only the rear part of the head and the first four segments of the thorax. Varieties range in colour from shades of brown to vivid colours, with more than 450 species of mantis shrimp known.