| Florometra serratissima | |
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| Species: | F. serratissima |
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| Florometra serratissima (AH Clark, 1907) [1] | |
Florometra serratissima is a species of crinoid or feather star in the family Antedonidae. It is found off the Pacific coast of North America, usually in deep water.
Like other feather stars, F. serratissima has a stalk, a calyx and a set of arms. The mouth is located on the upper side at the centre of the calyx, with the anus nearby. Surrounding the calyx are five jointed limbs. These branch at the base to form ten or more arms, each of which has jointed appendages known as pinnules growing from it, in a feather-like fashion. The centre of each arm has an ambulacral groove down which food particles are moved by cilia to the mouth. When the arms are fully extended to either side, the crinoid may measure 25 cm (10 in) across. On the aboral (under) surface are clawlike cirri which grasp the seabed. This feather star is reddish-brown. Juveniles have a long stalk. [2]
F. serratissima is native to the Pacific coast of North America, its range extending from the Shumagin Islands and Sanak Islands off Alaska southward to Isla Natividad off Baja California. Its depth range is from 11 to 1,252 m (36 to 4,108 ft), [1] but it is more commonly found in deep water. [2]
These crinoids can live on either rocks or soft sediment, and can move around using their cirri as feet, or can swim by beating their arms; they are suspension feeders, choosing locations with strong currents and extending their arms to catch plankton floating past. [3] Although the arms of F. serratissima have special joints known as syzygies where they are designed to part when stressed, researchers grasping this crinoid found the arms invariably broke off at the base. If it loses an arm, by autotomy or predation, the arm can be regenerated, the speed of regeneration being independent of whether the regrowth is happening from a long or a short stump. [4]
An echinoderm is any member of the phylum Echinodermata of marine animals. The adults are recognizable by their radial symmetry, and include starfish, sea urchins, sand dollars, and sea cucumbers, as well as the sea lilies or "stone lilies". Adult echinoderms are found on the sea bed at every ocean depth, from the intertidal zone to the abyssal zone. The phylum contains about 7000 living species, making it the second-largest grouping of deuterostomes, after the chordates. Echinoderms are the largest phylum that has no freshwater or terrestrial members.
Crinoids are marine animals that make up the class Crinoidea, one of the classes of the phylum Echinodermata, which also includes the starfish, brittle stars, sea urchins and sea cucumbers. Those crinoids which, in their adult form, are attached to the sea bottom by a stalk are commonly called sea lilies, while the unstalked forms are called feather stars or comatulids, being members of the largest crinoid order, Comatulida.
Pentacrinites is an extinct genus of crinoids that lived from the Hettangian to the Bathonian of Asia, Europe, North America, and New Zealand. Their stems are pentagonal to star-shaped in cross-section and are the most commonly preserved parts. Pentacrinites are commonly found in the Pentacrinites Bed of the Early Jurassic of Lyme Regis, Dorset, England. Pentacrinites can be recognized by the extensions all around the stem, which are long, unbranching, and of increasing length further down, the very small cup and 5 long freely branching arms.
Comasteridae is a family of crinoids.
Antedon bifida is a species of crinoid in the family Antedonidae commonly known as the rosy feather star. It is found in north west Europe.
Comatulida is an order of crinoids. Members of this order are known as feather stars and mostly do not have a stalk as adults. The oral surface with the mouth is facing upwards and is surrounded by five, often divided rays with feathery pinnules. Comatulids live on the seabed and on reefs in tropical and temperate waters.
Davidaster discoideus or the beaded crinoid is a species of feather star in the family Comasteridae. It was previously known as Nemaster discoidea but the World Register of Marine Species has determined that the valid name is Davidaster discoideus. It is found on reefs in the Caribbean Sea and northern coast of South America.
Comaster schlegelii, the variable bushy feather star, is a crinoid in the family Comasteridae. It was previously classified as Comanthina schlegeli but further research showed that it was better placed in the genus Comaster. It is found on shallow water reefs in the western Pacific Ocean.
Metacrinus rotundus, the Japanese sea lily, is a marine invertebrate, a species of stalked crinoid in the family Isselicrinidae. It is a species found off the west coast of Japan, and is living near the edge of the continental shelf, around 100-150m deep. This is the shallowest species among the extant stalked crinoids.
Oxycomanthus bennetti, the Bennett's feather star, is a species of crinoid belonging to the family Comasteridae. It is found in shallow water in the Indo-Pacific between northern Australia and southeast Asia.
Himerometra robustipinna is a species of crinoid belonging to the family Himerometridae.
Antedon mediterranea is a species of stalkless crinoid in the family Antedonidae, commonly known as the Mediterranean feather star. It is found on the seabed at moderate depths in the Mediterranean Sea. It is a filter feeder and captures plankton with its long feathery arms.
Bourgueticrinida is an order of crinoids that typically live deep in the ocean. Members of this order are attached to the seabed by a slender stalk and are known as sea lilies. While other groups of crinoids flourished during the Permian, bourgueticrinids along with other extant orders did not appear until the Triassic, following a mass extinction event in which nearly all crinoids died out.
Ptilometra australis, the passion flower feather star, is a species of crinoid. It is native to the coasts of southeastern Australia where it is found on reefs, in estuaries and bays at depths down to about 110 metres (360 ft).
Leptometra celtica is a marine invertebrate and species of crinoid or feather star of the Leptometra genus in the family Antedonidae. It is found in the Atlantic Ocean around the coasts of north west Europe. The presence of L. celtica and L. phalangium is considered to be a good indication of nearby shelf breaks, general bottom currents, and areas of high gross productivity as they are suspension-feeders, hence their proliferation in productive environments.
Agaricocrinus is a genus of extinct crinoids, belonging to the family Coelocrinidae.
Delocrinus is a genus of extinct crinoids, belonging to the family Catacrinidae. Specimens have been found in Kansas Missouri Nebraska Nevada Oklahoma, Arizona, Iowa, Texas, Utah and Virginia.
Aporometra wilsoni is a marine invertebrate, a species of crinoid or feather star in the family Aporometridae. It is found in shallow water around the coasts of southern Australia.
Notocrinus virilis is a marine invertebrate, a species of crinoid or feather star in the family Notocrinidae. It is found in deep water in the Southern Ocean around the coasts of Antarctica and adjacent islands. A sea snail sometimes parasitizes it.
Cenometra bella is a species of crinoids belonging to the genus Cenometra. They can have up to 30 arms and can be of variable colours but are often characterised by a marked contrast between the extending free-arms and the feathery pinnules. This species clings to its support and moves around by its feet-like cirri.