All About Sea Urchins

All About Sea Urchins

Sea Urchin is a delicacy in many cultures and knowledge is key when it comes to sourcing, storing and preparing sea urchin.

At Sea Urchin Harvest we have been catching and selling sea urchin uni for over 35 years! We are here to give you a lesson all about Australian uni.

What Is Behind The Spines?

Sea Urchins are ancient organisms, they do not have organs such as a heart or blood vessels. They are made up of mouth, gut tube, a primitive nervous system and a set of five delicate tongues of gonads sheathed in a spiky hard shell, which is the edible part commonly known as sea urchin roe or uni. The gonads execute both reproductive and nutrient storage functions.

Diversity Of Species

There are four species of sea urchins commercially harvested in Australia. Their common names can be confusing as the colour descriptions do not coincide with the apparent colour of the sea urchin.

Centrostephanus rodgersii is known as purple sea urchin or the long spine sea urchin. It makes up the majority of the commercial catch in Australia. These urchins are located off the coasts of New South Wales, eastern Victoria, the east coast of Tasmania and the eastern Bass Strait islands. These spawn in winter from late June/July to August and are at peak flavour in autumn.

Heliocidaris tuberculata is know as the red sea urchin. These can be harvested from southern Queensland to the South Coast of New South Wales. They spawn from February to October based upon their location. Generally, they at peak flavour in late spring to early summer

Heliocidaris erythrogramma is known as the green, white or purple sea urchin. These are located in southern Australia from sub-tropical New South Wales to Shark Bay in Western Australia and also Tasmania. They spawn in the summer and are best consumed in spring.

Tripneustes gratilla are known as lamington sea urchins. These sea urchins naturally occur in both Japan and Australia. They are no longer commercially harvested from the wild as a result of low numbers; however they will be farmed and commercially available in the upcoming future. Once farming of this urchin commences it will produce superb uni throughout the year.

Flavour Profile

A sea urchin that has just been picked from the sea, cracked open and washed in the ocean tastes sweet yet creamy with a burst of umami. The texture is soft and pillowy, melting in your mouth like butter.

The flavour and condition of uni is determined by a number of factors such as the species of urchin harvested; the type, quantity and quality of food consumed; the stage of the reproductive cycle; the water temperature and the amount of daylight and weather.


If you aren’t able to forage for sea urchins yourself, they should be bought live from tanks. Live sea urchins should be kept in suitably maintained holding tanks in which they will preserve their vitality and quality.

Uni is at its best when the urchins are in their peak nutrient-rich stage. This is the stage before the sea urchins are preparing to spawn.

If the uni is weepy and milky, the urchins are in their reproductive stage and texture will be disappointing.

Alternatively, if the uni is skinny or empty, the urchins have just spawned and will not be suitable for harvesting.


Sea urchins should be processed within 24 hours of obtaining them live. It is not recommended to keep sea urchins out of water for lengthened periods of time. The uni should be extracted as soon as possible following removal of the sea urchin from its holding tank.


Once the uni is removed from the shell, any membrane should be removed and the uni scooped out with a spoon or knife.

Scissors can also be used, entering the mouth of the sea urchin and cutting around the mouth with care before cleaning the inside with salt water. The spines can be trimmed so the urchin can sit nicely on the plate for presentation. Any unused uni can be stored in salt water in the refrigerator for the next few days.

About Sea Urchin Harvest

Sea Urchin Harvest sells premium Sea Urchin Uni & Sea Urchin Roe from Australia’s iconic east coast. All of our Uni is caught fresh and delivered fresh to you! If you have any questions about ordering Sea Urchin Uni for your commercial business please get in contact via the Contact Us Page or alternatively call us on 0414 441 136.

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