''Cidaris blakei'' is a species of

sea urchin Sea urchins or urchins () are echinoderms in the class (biology), class Echinoidea. About 950 species live on the seabed, inhabiting all oceans and depth zones from the intertidal zone to deep seas of . They typically have a globular body cove ...

s of the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Cidaridae Cidaridae is a family of sea urchins in the order Cidaroida. Description and characteristics Cidarid sea urchins are characterized by their stout skeleton : the test is thick and hard, with massive perforated tubercles (never crenulated) su ...

. Its armour is covered with spines of three types, one unique type being extended and fan-like, making it easily recognized.

Alexander Agassiz Alexander Emmanuel Rodolphe Agassiz (December 17, 1835March 27, 1910), son of Louis Agassiz and stepson of Elizabeth Cabot Agassiz, was an American scientist and engineer. Biography Agassiz was born in Neuchâtel, Switzerland, and immigrated t ...

first described it scientifically in 1878. It is present on the seabed in deep waters in the

Gulf of Mexico The Gulf of Mexico () is an oceanic basin and a marginal sea of the Atlantic Ocean, mostly surrounded by the North American continent. It is bounded on the northeast, north, and northwest by the Gulf Coast of the United States; on the southw ...

and

the Bahamas The Bahamas, officially the Commonwealth of The Bahamas, is an Archipelagic state, archipelagic and island country within the Lucayan Archipelago of the Atlantic Ocean. It contains 97 per cent of the archipelago's land area and 88 per cent of ...

Taxonomy

''Cidaris blakei'' was first described by the American zoologist

in 1878. It was among many deep sea animals dredged up from abyssal depths in the Gulf of Mexico during the explorations of the '' USC&GS George S. Blake'', one of the first United States oceanographic research vessels, and from which it derives its

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

. The genus name is

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

for a headdress or tiara worn by ancient Persian kings.

Description

Although their appearance is quite variable, other members of the genus ''

Cidaris ''Cidaris'' is a genus of pencil sea urchins. Species According to the World Register of Marine Species (WoRMS), the genus Cidaris contains the following extant species *''Cidaris abyssicola'' (Agassiz, 1869) *'' Cidaris annulata'' (Gray, 18 ...

'' have long cylindrical blunt or pointed spines that are not covered with skin as are most sea urchin spines. As a result, barnacles, tube worms and other

epizoic An epibiont (from the Ancient Greek meaning "living on top of") is an organism that lives on the surface of another living organism, called the basibiont ("living underneath"). The interaction between the two organisms is called epibiosis. An ep ...

organisms grow on them. The spines of ''C. blakei'' are present in three different forms, one form being broad, flat and paddle-shaped. They are also naked and epizoics grow on them, but the function of these strange-shaped spines is unclear.

Distribution

This sea urchin is found in the tropical western

Atlantic Ocean The Atlantic Ocean is the second largest of the world's five borders of the oceans, oceanic divisions, with an area of about . It covers approximately 17% of Earth#Surface, Earth's surface and about 24% of its water surface area. During the ...

. Its range includes the

and deepwater areas off

, where they were collected from the seabed at depths of around .

Ecology

Larvae of ''C. blakei'' are

planktotrophic Marine larval ecology is the study of the factors influencing dispersing larvae, which many marine invertebrates and fishes have. Marine animals with a larva typically release many larvae into the water column, where the larvae develop before meta ...

, that is to say they spend a long time living in the water column, taking four months to develop from egg to

metamorphosis Metamorphosis is a biological process by which an animal physically develops including birth transformation or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and different ...

, and as a result can disperse widely. During this time they are sustained at first by the egg yolk, and later feed on

zooplankton Zooplankton are the heterotrophic component of the planktonic community (the " zoo-" prefix comes from ), having to consume other organisms to thrive. Plankton are aquatic organisms that are unable to swim effectively against currents. Consequent ...

and

phytoplankton Phytoplankton () are the autotrophic (self-feeding) components of the plankton community and a key part of ocean and freshwater Aquatic ecosystem, ecosystems. The name comes from the Greek language, Greek words (), meaning 'plant', and (), mea ...

. However, researchers think that they would be unlikely to survive the warmer temperatures present higher in the water column, and are therefore unable to migrate vertically.

References

{{DEFAULTSORT:Cidaris blakei Animals described in 1878 Cidaridae Taxa named by Alexander Agassiz