A Sea Urchin Primer, Plus Where to Eat It in New York City

Sea urchin is the ingredient of the moment. While it was once confined to being a bit player in a sushi or sashimi assortment — a sort of odd man out among firmer and less colorful seafood — for the last five years or so it’s been popping up everywhere. Chefs are dropping them on pizzas, using them as taco filling, churning them with butter, and incorporating urchins into the ubiquitous contemporary dining format known as "bowls." As a friend pointed out, "Really, it’s just an easy valued-added luxury ingredient that goes with anything — well, almost anything."

In case you don’t already know everything there is to know about these spiny ocean denizens, here’s a sea urchin primer.

What are sea urchins, anyway?
The sea urchin is a spiny animal that lives only in salt water. It belongs to the marine phylum popularly known as echinoderms, all of which display radial symmetry and have a calcareous exoskeleton, and most of which are round. The taxonomic category also includes sand dollars, starfish, and sea cucumbers. There are over 700 species of sea urchins found in the world’s oceans. Other common names include sea eggs and sea hedgehogs.

Do sea urchins move or are they stationary?Sea urchins can move across the sea floor using hundreds of tiny feet. These are called tube feet and exude a sticky substance that helps them adhere to whatever they’re walking on.

Sea urchin exoskeleton and cross-section.

What are some other characteristics of sea urchins?
Sea urchins have spines that stick out sideways and upwards, averaging one to two inches — although one species has spines that can reach six inches in length. In common with other echinoderms, they are able to regenerate lost tissue. If you break off a spine, it grows back. Sea urchins have exoskeletons made of calcium carbonate covered by a thin layer of skin, and the spines are covered with the same epidermis.

Are the spines poisonous if you step on them while swimming?
No. But it can be very painful, like touching a porcupine.

Where are sea urchins found?
Sea urchins are nearly universal in the world’s oceans, found in climates that range from tropical to near-polar. They live at nearly all depths. Not all are edible. Specimens have been collected at 21,000 feet in the Java Trench, just southwest of Indonesia. There is a major fishery in California, where 500 divers are licensed, and this has become the state’s largest seafood export — mainly to Japan. There are 23 countries that now export sea urchins, including Russia, Canada, both Koreas, Chile, and China. Nearly 50% of sea urchins eaten in Japan are harvested in the United States.

What are the principal sources of the sea urchin we eat in New York City?
Most sea urchins served in New York City reportedly come from Maine, Massachusetts, or California.

What part of the sea urchin do we actually eat? What is it anatomically?
The anus of the sea urchin is found at its topmost point, and the five orange "tongues" or "corals" that radiate around it just under the shell are the egg- or sperm-bearing gonads of the animal — so it’s the sex organs we’re consuming when we eat sea urchins.

What do sea urchins taste like?
Some folks liken them to lobster, but with a sweeter flavor. Others mention the adjectives "nutty" or "briny." Still others say it’s all about the texture and color, and downplay the actual flavor. Though the creature looks bumpy, like a mammalian tongue, in your mouth it’s all smoothness, like egg custard but firmer.

What cultures relish sea urchins and what are the names for it in other languages?
Known as riccio de mare ("sea curls") in Italy, sea urchins are eaten raw with a squeeze of lemon, or less frequently cooked with pasta, which renders them hard and crumbly, though still creamy. To Chileans and Peruvians, who also eat it raw, the sea urchin is known as erizo de mar ("hedgehog of the sea"). Koreans eat sea urchin as sushi and in seaweed soups. In Japan, of course, sea urchin is known as uni, and usually eaten raw in sushi with a distinctive collar of nori.

What are the drawbacks of using sea urchins in restaurants?
In general, sea urchins cannot be successfully frozen and thawed, so they have to be harvested and quickly transported to restaurants. They are also relatively expensive.

How can you tell if sea urchin is not fresh enough?
If it flings off an iodine odor and looks desiccated rather than glistening, stay away!

Is sea urchin sustainable?
It depends on where it comes from. According to the Monterey Bay Aquarium’s Seafood Watch website (note that the site refers to the edible part of the sea urchin as 'roe'): "North American urchin populations vary widely. Many are overfished, so it's important to know where your urchin roe comes from. Roe from Canada is a ‘Best Choice,’ roe from California is a ‘Good Alternative,’ and roe from Maine is on the ‘Avoid’ list." So sea urchin sourced in Maine is considered at least partly endangered.

Now click through below to see where to eat sea urchin around New York City: