Description
Also known as Black Longspine Urchin, Diadem Sea Urchin, Diadem Urchin, Hatpin Sea Urchin, Hatpin Urchin, Long-spined Black Sea Urchin, Long-spined Sea Urchin, Needle-spined Urchin, Pacific Long-spined Black Sea Urchin, Porcupine Sea Urchin, Sea Hedgehog, Setosum Spined Urchin, Star Urchin.
Found singly or in large groups, moving across rubble, sand, shingle, and seagrass beds, in bays and lagoons.
They feed nocturnally on algae.
Length - 20cm
Depth - 0-70m
Widespread Mediterranean, Indo-Pacific
Amongst their spines these sea urchins may have Banggai Cardinalfish - Pterapogon kauderni
http://www.whatsthatfish.com/fish/banggai-cardinalfish/6
Tubed Cardinalfish - Siphamia tubifer
http://www.whatsthatfish.com/fish/tubed-cardinalfish/3024
These large sea urchin with long and mobile spines can often be found with fish swimming in between their spines for protection.
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/Diadema_setosum
9 comments
Posted by Alfred HunteOk, Nobody likes to hear this:- spent the last 30 years of my life in the sea in the Caribbean. many encounter with the Black sea urchin, my mother tried a lot of Home remedies , was not successful spines are very brittle. a poultice of Hot candlewax worked a little, but the foolproof remedy we found [ very painful ] take a smooth rock and pound the wound. this breaks up the spines and they are dissolved into the bloodstream. sounds outrageous but works!!!
Posted by CapitanissaI just got a short piece in my finger and very successfully "dissolved" it by soaking in vinegar for an hour. I highly recommend this method. The long spine urchin has only recently shown up in the Dodecanese where mostly we see short spine black or purple and some red, or beautiful red with white tips - and these have much more blunt spines.
Posted by William DeanThese are now in the Med. There were a load of them near Marmaris/ Dalaman on the rocky coast.
Posted by @fishx6Wow bad luck!
Posted by Hazel SmithI accidentally whacked a Black Sea urchin whilst swimming backstroke in shallow water in Thailand. A rock under surface! I hit it as hard as I possibly could with the palm of my hand. The pain was incredible! A few days later I pulled a 2+cm long spine out from the palm of my hand. 2 x Ray's and an ultrasound scan a few weeks later and everyone kept reassuring me everything was fine, nothing showing. An hour long surgery 4 months later to remove spine tips and a massive scar!
Posted by Bahar AlgonWhen the needles get in the skin put some olive oil on a cotton pad. Tie it around and the next morning the needle is gone. Painless and a sure solution.
Posted by rameshI have attacked by these fish in pattaya beach. It is so painful and I had antibiotics capsules. so please be careful while swimming in certain places in Bangkok beaches. It is often found near the coral reef islands.
Posted by @fishx63 aspects i have come across 1) they often have vibrio contamination (as does coral etc) and cause symptoms for months, so an appropriate antibiotic is usually appropriate early on (doxycycline/cipro). 2) i have read (hear say evidence) of paralysis and nasty things happening after innocuous stings from urchins weeks later.! 3)Been pricked myself and nothing happened.(but i went fishing under Local anaesthetic to get all the bits out)
Posted by PhillipA patient of mine was 'stung' multiple times by one of these sea urchins leaving part of their sting in the skin. It was painful at the time but these spike tips are still embedded in the skin. Anyone know what the consequences are if these tips are left in? Please advise.