''Cidaris blakei'' is a species of

sea urchin Sea urchins () are spiny, globular echinoderms in the class Echinoidea. About 950 species of sea urchin live on the seabed of every ocean and inhabit every depth zone from the intertidal seashore down to . The spherical, hard shells (tests) of ...

s of the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

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) sur ...

. 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 to ...

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

Gulf of Mexico The Gulf of Mexico ( es, Golfo de México) is an oceanic basin, ocean basin and a marginal sea of the Atlantic Ocean, largely surrounded by the North American continent. It is bounded on the northeast, north and northwest by the Gulf Coast of ...

and

the Bahamas The Bahamas (), officially the Commonwealth of The Bahamas, is an island country within the Lucayan Archipelago of the West Indies in the Atlantic Ocean, North Atlantic. It takes up 97% of the Lucayan Archipelago's land area and is home to ...

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. The genus name is

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

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, ...

'' 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 epi ...

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 oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...

. 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 met ...

, 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 or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation. Some inse ...

, 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 animal component of the planktonic community ("zoo" comes from the Greek word for ''animal''). Plankton are aquatic organisms that are unable to swim effectively against currents, and consequently drift or are carried along by ...

and

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

. 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