WHATSTHATFISH
Sea stars & urchins

Longspine Black Urchin

Diadema savignyi

Also known as: Banded Diadem Urchin, Black Longspine Urchin, Diadema Sea Urchin, Longspine Sea Urchin, Long-spined Black Urchin, Long-spined Sea Urchin, Long-spined Urchin, Needle-spined Urchin, Needle-spined Sea Urchin, Savigny's Longspine Sea Urchin, Sea Hedgehog, Tropical Spined Sea Urchin

Adult
@fishx6 · Lembeh, Indonesia · August 20081 / 9
01

Overview

Found singly, or in large groups, hiding under rocks during the day, active at night over shallow waters, often around harbours and wharfs, especially where there has been storm damage.

Differs from D. setosum (Needle Urchin) in that it lacks red ring around the anus but is the more common of the two in South Africa.

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. Black urchin with extremely long needles. Dotted blue lines along the body.

02

How to identify

COLOURS
Body shape
spines

Tap any trait to see other fish that share it.

03

Habitat & where to find it

  • Range · Indo-Pacific
  • Exact location · 2
  • Country only · 7
LIVES IN

Found singly, or in large groups, hiding under rocks during the day, active at night over shallow waters, often around harbours and wharfs, especially where there has been storm damage.

04

Adult photos 9

05

Discussion

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    ALL STAGES
    FOR THE MARINE-BIOLOGY CURIOUS

    Deep dive

    Taxonomy

    1. kingdomAnimalia
    2. phylumEchinodermata
    3. classEchinoidea
    4. orderDiadematoida
    5. familyDiadematidae
    6. genusDiadema
    7. speciesDiadema savignyi (Audouin, 1809)

    SourcesWoRMSWikipedia

    06

    More in the family

    Sea Urchins (Diadematidae)