Ophiocoma wendtii
Encyclopedia
The brittle star
Ophiocoma wendtii inhabits coral reef
s from Bermuda
to Brazil
. It is known for its advanced compound eyes.
Brittle stars have long, thin arms emanating from a small, disk-shaped body and are about the size of an outstretched human hand. They belong to the phylum of echinoderm
s, which includes sea urchins, sea cucumbers, and sea stars.
crystals. In addition to functioning as an armor and giving structural support, the crystals make up its unique visual systems. They minimize spherical aberration and can detect the direction of incoming light. The lenses work by filtering and focusing light on an underlying photoreceptor system. Nerve bundles under each lens, presumed to be light-sensitive, transmit the optical information to the rest of the nervous system.
The only known animals to employ a similar visual system were the now-extinct trilobite
s. Phototropic chromatophores can change O. wendtii's color and regulate how much light will reach the photoreceptors.
Brittle star
Brittle stars or ophiuroids are echinoderms in the class Ophiuroidea closely related to starfish. They crawl across the seafloor using their flexible arms for locomotion. The ophiuroids generally have five long slender, whip-like arms which may reach up to in length on the largest specimens...
Ophiocoma wendtii inhabits coral reef
Coral reef
Coral reefs are underwater structures made from calcium carbonate secreted by corals. Coral reefs are colonies of tiny living animals found in marine waters that contain few nutrients. Most coral reefs are built from stony corals, which in turn consist of polyps that cluster in groups. The polyps...
s from Bermuda
Bermuda
Bermuda is a British overseas territory in the North Atlantic Ocean. Located off the east coast of the United States, its nearest landmass is Cape Hatteras, North Carolina, about to the west-northwest. It is about south of Halifax, Nova Scotia, Canada, and northeast of Miami, Florida...
to Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
. It is known for its advanced compound eyes.
Brittle stars have long, thin arms emanating from a small, disk-shaped body and are about the size of an outstretched human hand. They belong to the phylum of echinoderm
Echinoderm
Echinoderms are a phylum of marine animals. Echinoderms are found at every ocean depth, from the intertidal zone to the abyssal zone....
s, which includes sea urchins, sea cucumbers, and sea stars.
Visual system
Its arms are covered with calciteCalcite
Calcite is a carbonate mineral and the most stable polymorph of calcium carbonate . The other polymorphs are the minerals aragonite and vaterite. Aragonite will change to calcite at 380-470°C, and vaterite is even less stable.-Properties:...
crystals. In addition to functioning as an armor and giving structural support, the crystals make up its unique visual systems. They minimize spherical aberration and can detect the direction of incoming light. The lenses work by filtering and focusing light on an underlying photoreceptor system. Nerve bundles under each lens, presumed to be light-sensitive, transmit the optical information to the rest of the nervous system.
The only known animals to employ a similar visual system were the now-extinct trilobite
Trilobite
Trilobites are a well-known fossil group of extinct marine arthropods that form the class Trilobita. The first appearance of trilobites in the fossil record defines the base of the Atdabanian stage of the Early Cambrian period , and they flourished throughout the lower Paleozoic era before...
s. Phototropic chromatophores can change O. wendtii's color and regulate how much light will reach the photoreceptors.