Red Urchin (Astropyga radiata)

Also known as Bluespot Sea Urchin, Blue-spotted Sea Urchin, Blue-spotted Urchin, Iridescent Sea Urchin, False Fire Urchin, Fire Urchin, Hatpin Urchin, Longspine Urchin, Long-spined Sea Urchin, Radiant Fire Urchin, Radiant Sea Urchin, Radiating Hatpin Urchin, Rainbow Fire Urchin, Red Long Spine Urchin, Red Sea Urchin, Sea Hedgehog, Star Urchin, Walking Sea Urchin

Description

Also known as Bluespot Sea Urchin, Blue-spotted Sea Urchin, Blue-spotted Urchin, Iridescent Sea Urchin, False Fire Urchin, Fire Urchin, Hatpin Urchin, Longspine Urchin, Long-spined Sea Urchin, Radiant Fire Urchin, Radiant Sea Urchin, Radiating Hatpin Urchin, Rainbow Fire Urchin, Red Long Spine Urchin, Red Sea Urchin, Sea Hedgehog, Star Urchin, Walking Sea Urchin.

Found singly, or in large groups, moving across rubble, sand, and shingle, of bays and lagoons. Variable in colour.
They feed nocturnally on algae.
Length - 20cm
Depth - 0-60m
Widespread Indo-West Pacific

These large sea urchin with long and mobile spines can often be found with fish swimming in between their spines for protection.

[In the Caribbean the same sea urchin is called Astropyga magnifica.]

Sea Urchins use tubed feet to get around, often in large impenetrable masses for protection.
Sometimes they hitch a lift on the back of crabs.
They have well developed jaws for grinding their prey.
Their anus is on top in most sea urchins, except the heart urchins where it is at the rear.
Predators of sea urchins are triggerfish and large wrasses, who nibble away at their spines before turning them over to eat the fleshy undersides.
Sea Urchins are highly venomous and can piece through a wet-suit.
Some are sensitive to light and have the ability to shoot venom loaded spines at a short distance.
To be avoided!! Ref: https://en.wikipedia.org/wiki/Astropyga_radiata

7 comments

  1. Check out our blog on how fish and critters can appear in different places in the world!https://www.whatsthatfish.com/blog/right-fish-wrong-place/

  2. Posted by Lura L Burton
    June 03, 2021 at 13:14 pm - 1 person found this useful.

    Hello -- we recently found a radiant sea urchin in the Sea of Cortez near Guaymas. We have never seen one of these in the Sea of Cortez and in reading about them understand that they are Indo-Pacific. How in the world did this sea urchin get here?

  3. The Caribbean urchin is known as Astropyga magnifica, like ther Indo-pacific counterpart they can be found in large aggregations. In 1983-1984 there was an epidemic of the Long-spined Sea Urchin - Diadema antillarum, not sure about this one! The spines can give a very painful wound and often need antibiotics, and thorough removal of any broken spines. My own experience is that they don't dissolve as some books suggest but cause a nasty abscess, especially if other bugs or matter are on the spikes.

  4. Posted by juniper
    February 08, 2014 at 11:39 am - 1 person found this useful.

    hi saw one of these today in the virgin islands. They are magnificent, but are they invasive here? this is the first site I have seen that lists them in the Caribbean all others list them as indo-pacific. How venomous are they?thanks so much!

  5. Posted by johnmiller
    May 21, 2012 at 02:48 am - 1 person found this useful.

    Iphotographedaredlongspineurchinincosumel2/12locallytheycallthe"fantasticurchin"

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