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Conical Spider Crab

Xenocarcinus conicus

Description:

Identified by its host, the branching black coral (Antipathes sp.), X. conicus is able to transfer living matter from its host onto its carapace and leg joints for camouflage.

Habitat:

Typically found in the Indo-Pacific region.

Notes:

Spotted these critters on a bush-like coral at a depth of probably 12m during a day dive. There were two of them: the first 2 photos show one, and the other two show the other. The latter seems to have thicker appendages, and you can just make out the claw in the 3rd photo. (Just to be sure you can see the critter clearly, the 3rd & 4th photo shows it hanging upside down.)

No species ID suggestions

15 Comments

Blogie
Blogie 2 years ago

Came across more information, and now I think this is X. conicus and not X. tuberculatus. Sheesh... identifying marine critters is such a challenge! :D

Blogie
Blogie 2 years ago

Updated this spotting. I do believe this is X. turberculatus. I hope others can confirm it.

Blogie
Blogie 2 years ago

I hope so too, Eric. I've emailed WhatsThatFish.com about this already, but no reply yet. I must say, however, that usually they're pretty reliable when it comes to ID'ing critters. But of course, nobody's perfect. :)

Eric Noora
Eric Noora 2 years ago

Well just that like you I have yet to find anything similar when googling I. edwardsi or Edward's Purse Crab. Except that from Whats that Fish site which is the same pic as above. Maybe others can help verify this then...

Blogie
Blogie 2 years ago

Yeah it is, Eric, but I don't quite agree with them yet...

Eric Noora
Eric Noora 2 years ago

Hi Blogie. So is it confirmed that this is an Ixa edwardsi? You photo is already uploaded in the link in Whats that Fish site as such.

LealikiKanoa
LealikiKanoa 2 years ago

Incredible!

Blogie
Blogie 2 years ago

Thanks for the suggestion, nigel.brennan. However, are you positive that this is Ixa edwardsi? I googled that species and I got pictures of crab that look a lot different from this one...

Eric Noora
Eric Noora 2 years ago

You're welcome :-)

Blogie
Blogie 2 years ago

Thanks for the heads-up, Eric! I think it might be X. tuberculatus, but that species seems to prefer whip coral... I'll keep looking.

Eric Noora
Eric Noora 2 years ago

Hi Blogie. This might be a spider crab. Try checking the Xenocarcinus species - just not sure which - X. depressus, X. conicus or X. tuberculatus :-)

Blogie
Blogie 2 years ago

Will do, Leuba!

Leuba Ridgway
Leuba Ridgway 2 years ago

I am no expert on crustaceans but it looks a little too robust for a shrimp especially the carapace - but you must have seen many different shrimps in your time!. It reminds me of a modified spider crab - seems to have a slightly broader posterior part ? - I hope you find out what it is - will be interested to know.

Blogie
Blogie 2 years ago

LOL Leuba! :D
Your observations are all correct. Don't know if it's not a good swimmer, but I do believe it only crawls on the coral's stalks. Very interesting about its eyes, no? Makes me think now that it might be a shrimp instead...

Leuba Ridgway
Leuba Ridgway 2 years ago

I can make out the legs and perhaps a fat claw ( pic 3) - the legs have hooky ends(pic 1). May not be a good swimmer ? This crustacean appears to have a narrow body (pic 3) with a pointy anterior part of the carapace. I think I can make out an eye on the side of the pointy bit and it is not on a stalk ! When you find out, you can tell me if any of this is right.
I think you've made-up this whole thing, Blogie ....seriously, you do find such amazing creatures. Well done and thanks for sharing.

Biliran, Philippines

Lat: 11.46, Long: 124.01

Spotted on Mar 3, 2012
Submitted on Mar 7, 2012

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