Definitions for sea urchin
sea urchin

Princeton's WordNetRate this definition:0.0 / 0 votes

1. sea urchinnoun

   shallow-water echinoderms having soft bodies enclosed in thin spiny globular shells

WiktionaryRate this definition:0.0 / 0 votes

1. sea urchinnoun

   Any of many marine echinoderms, of the class Echinoidea, commonly found in shallow water, having a complex chewing structure named Aristotle's lantern

2. Etymology: sea + urchin (meaning hedgehog), due to the similarity in appearance to the hedgehog.

WikipediaRate this definition:0.0 / 0 votes

1. 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 5,000 meters (16,000 ft; 2,700 fathoms). The spherical, hard shells (tests) of sea urchins are round and covered in spines, ranging in length from 3 to 10 cm (1 to 4 in), though the black sea urchin can have spines as long as 30 cm (12 in). Sea urchins move slowly, crawling with tube feet, and also propel themselves with their spines. Although algae are the primary diet, sea urchins also eat slow-moving (sessile) animals. Predators that eat sea urchins include a wide variety of fish, starfish, crabs, marine mammals. Sea urchins are also used as food especially in Japan. Like all echinoderms, adult sea urchins have fivefold symmetry, but their pluteus larvae feature bilateral (mirror) symmetry, indicating that the sea urchin belongs to the Bilateria group of animal phyla, which also comprises the chordates and the arthropods, the annelids and the molluscs, and are found in every ocean and in every climate, from the tropics to the polar regions, and inhabit marine benthic (sea bed) habitats, from rocky shores to hadal zone depths. The fossil record of the Echinoids dates from the Ordovician period, some 450 million years ago. The closest echinoderm relatives of the sea urchin are the sea cucumbers (Holothuroidea), both of which are deuterostomes, a clade that includes the chordates. (Sand dollars are a separate order in the sea urchin class Echinoidea.) The animals have been studied since the 19th century as model organisms in developmental biology, as their embryos were easy to observe. That has continued with studies of their genomes because of their unusual fivefold symmetry and relationship to chordates. Species such as the slate pencil urchin are popular in aquariums, where they are useful for controlling algae. Fossil urchins have been used as protective amulets.

Webster DictionaryRate this definition:0.0 / 0 votes

1. Sea urchin

   any one of numerous species of echinoderms of the order Echinoidea

WikidataRate this definition:0.0 / 0 votes

1. Sea urchin

   Sea urchins or urchins are small, spiny, globular animals which, with their close kin, such as sand dollars, constitute the class Echinoidea of the echinoderm phylum. There are c. 950 species of echinoids inhabiting all oceans from the intertidal to 5000 meters deep. Their shell, or "test", is round and spiny, typically from 3 to 10 cm across. Common colors include black and dull shades of green, olive, brown, purple, blue, and red. They move slowly, feeding mostly on algae. Sea otters, wolf eels, triggerfish, and other predators feed on them. Their "roe" is a delicacy in many cuisines. The name "urchin" is an old name for the round spiny hedgehogs that sea urchins resemble.

Matched Categories

1. • Echinoderm

Anagrams for sea urchin »

1. echiurans

How to pronounce sea urchin?

1. Alex

   US English

   David

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   Mark

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   Daniel

   British

   Libby

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   Mia

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   Karen

   Australian

   Hayley

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   Natasha

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   Priya

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   Neerja

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   Zira

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   Oliver

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   Fred

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How to say sea urchin in sign language?

Numerology

1. Chaldean Numerology

   The numerical value of sea urchin in Chaldean Numerology is: 4

2. Pythagorean Numerology

   The numerical value of sea urchin in Pythagorean Numerology is: 8

Examples of sea urchin in a Sentence

1. Atchan Tamaki:

   The lobster fishermen kept asking me if there was a market for sea urchin because they were getting a lot of them in the traps.

References

1. ^ Princeton's WordNet
   http://wordnetweb.princeton.edu/perl/webwn?s=sea urchin
2. ^ Wiktionary
   https://en.wiktionary.org/wiki/Sea_Urchin
3. ^ Wikipedia
   https://en.wikipedia.org/wiki/Sea_Urchin
4. ^ Webster Dictionary
   https://www.merriam-webster.com/dictionary/sea urchin
5. ^ Wikidata
   https://www.wikidata.org/w/index.php?search=sea urchin