Seafood of the Week - Sea Urchin

The sea urchin (Echinus melo)

Sea urchins or urchins, sometimes called sea hedgehogs, are small, spiny, globular animals which, with their close kin, such as sand dollars, constitute the class Echinoidea of the echinoderm phylum. About 950 species of echinoids inhabit all oceans from the intertidal to 5000 m deep. The shell, or "test", of sea urchins is round and spiny, typically from 3 to 10 cm (1.2 to 3.9 in) across. Common colors include black and dull shades of green, olive, brown, purple, blue, and red. Sea urchins move slowly, feeding mostly on algae. Sea otters, sea stars, wolf eels, triggerfish, and other predators feed on sea urchins. Their roe is a delicacy in many cuisines. The name "urchin" is an old name for the round spiny hedgehogs which sea urchins resemble.







Sea urchins are members of the phylum Echinodermata, which also includes sea stars, sea cucumbers, brittle stars, and crinoids. Like other echinoderms, they have five-fold symmetry (called pentamerism) and move by means of hundreds of tiny, transparent, adhesive "tube feet". The symmetry is not obvious in the living animal, but is easily visible in the dried test. Echinodermate means "spiny skin" in Greek.
Specifically, the term "sea urchin" refers to the "regular echinoids", which are symmetrical and globular, and includes several different taxonomic groups: the order Echinoida, the order Cidaroida or "slate-pencil urchins", which have very thick, blunt spines, and others. Besides sea urchins, the class Echinoidea also includes three groups of "irregular" echinoids: flattened sand dollars, sea biscuits, and heart urchins.
Together with sea cucumbers (Holothuroidea), they make up the subphylum Echinozoa, which is characterized by a globoid shape without arms or projecting rays. Sea cucumbers and the irregular echinoids have secondarily evolved diverse shapes. Although many sea cucumbers have branched tentacles surrounding their oral openings, these have originated from modified tube feet and are not homologous to the arms of the crinoids, sea stars, and brittle stars.







The gonads of both male and female sea urchins, usually called sea urchin roe or corals, are culinary

Sea urchin (uni) served Japanese style as sashimi, with a dab of wasabi

delicacies in many parts of the world.
In cuisines around the Mediterranean, Paracentrotus lividus is often eaten raw, with lemon., and known as ricci on Italian menus where it is sometimes used in pasta sauces. It can also flavour omelettes, scrambled eggs, fish soup, mayonnaise, béchamel sauce for tartlets, the boullie for a soufflé, or Hollandaise sauce to make a fish sauce. In Chilean cuisine, it is served raw with lemon, onions, and olive oil.
Though the edible Strongylocentrotus droebachiensis is found in the North Atlantic, it is not widely eaten. However, sea urchins (called uutuk in Alutiiq) are commonly eaten by the Alaska Native population around Kodiak Island. It is commonly exported, mostly to Japan.
In the West Indies, slate pencil urchins are eaten.
On the Pacific Coast of North America, Strongylocentrotus franciscanus was praised by Euell Gibbons; Strongylocentrotus purpuratus is also eaten.
In New Zealand, Evechinus chloroticus, known as kina in Maori, is a delicacy, traditionally eaten raw. Though New Zealand fishermen would like to export them to Japan, their quality is too variable.
In Japan, sea urchin is known as and its roe can retail for as much as A$450/kg; it is served raw as sashimi or in sushi, with soy sauce and wasabi. Japan imports large quantities from the United States, South Korea, and other producers. Japanese demand for sea urchin corals has raised concerns about overfishing.