14 replies to this topic

[bobf]

This image was captured on a night dive under the Town Pier in Kralendijk, Bonaire. The critter in question was walking. This is a full frame image, no crop, full telephoto ( 21mm) on an Oly c4040. Would anyone care to make an educated guess?

tia,
bob

ExposureTime : 1/400Sec
FNumber : F4.0
ExposureProgram : Manual
ISOSpeedRatings : 100
DateTimeOriginal : 2004:03:11 21:04:09
MeteringMode : Spot
LightSource : DS 125 TTL
Flash : Fired
FocalLength : 21.00(mm)

[james]

Decorator crab covered in hydroids.

Cheers
James

[bobf]

thanks james....

[Leslie]

Hi --

Decorator crab with hydroids? Really? I can't see a single articulated joint, those white spots are way too regular for attached detritus, and the knobby bits are all along the edges. My guess is a juvenile frogfish or something related.

Cheers,
Leslie

[james]

Your guess is certainly as good as mine.

Cheers
James

[JPS]

Bob,

can you post full-res crops that would better enable looking for eyes? If you have shots from various angles that would be even better.

Br,
Jukka-Pekka

[bdickson]

I go with the decorator crab theory. Try sending a copy to Leslie Whaylen at REEF (leslie@reef.org). She has identified some weird critters for me over the years.

Bruce Dickson

[Art]

Hi folks

HMMMM ... was it walking like a crab or crawling slowly ?

in decorator crabs you usually see at least a few legs .. so I would say it's a juvenile sponge crab (Dromiidae) or a hermit carrying a sponge-, colonial tunicates- and maybe hydroid-overgrown shell

next time just turn the animal to see it from all sides ! and there will be no misteries

ciao

Art

[echeng]

bobf - in the future, can you be a bit more specific in the subject-line of your id request posts?

you know, something like "ID for crab in Bonaire"

[Giles]

being fair to bob .. he didn't know it was a crab, but i would also go with something like a frog fish .. it doesnt look very crab like to me.

[james]

Sponge crab is also an excellent guess. Sometimes, w/ a well set-up sponge crab, you can't see the crab at ALL.

Here's a not-so-well set-up sponge crab:



Cheers
James

[echeng]

being fair to bob .. he didn't know it was a crab, but i would also go with something like a frog fish .. it doesnt  look very crab like to me.

As much info as possible would be better than having a string of posts called "id please"

You know: location, description, etc.

Just trying to keep all this info as organized as possible...
-e

[bobf]

If you have shots from various angles that would be even better.

I took only one image.

As much info as possible would be better than having a string of posts called "id please"

Agree.

can you post full-res crops that would better enable looking for eyes? If you have shots from various angles that would be even better.

I increased the image to 100% and cropped accordingly.

imho and as I recall, it moved similar (consistent gait) to other crabs I have observed. It appeared underwater to be about in the 5 cm range in size. I've observed larger frogfish move, but not with similar coordination.

The forward movement of the creature was from right to left. iow, it was moving towards the left side of the image at time of capture.

Thanks to all for their interest and input. In the future I will document more carefully. This thread has taught me the importance of multiple views and better note taking.

regards,
b

[james]

Interesting! To me, it looks like a cut out piece of a barrel sponge - along w/ the commensal zooanthids that live on that type of sponge:



So perhaps it's a sponge crab, that has clipped off a piece of barrel sponge and it has grown pretty well onto its back.

Cheers
James

[Leslie]

Art's comments plus James' photo of the sponge with zooanthids is the clincher for me: sponge carrying dromid crab it is !
Leslie