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hermit crab

Coenobita sp.


A hermit crab. It may be Coenobita sp. Most species have long, spirally curved abdomens, which are soft, unlike the hard, calcified abdomens seen in related crustaceans. The vulnerable abdomen is protected from predators by a salvaged empty seashell carried by the hermit crab, into which its whole body can retract. Most frequently hermit crabs use the shells of sea snails (although the shells of bivalves and scaphopods and even hollow pieces of wood and stone are used by some species). The tip of the hermit crab's abdomen is adapted to clasp strongly onto the columella of the snail shell. As the hermit crab grows in size, it has to find a larger shell and abandon the previous one. This habit of living in a second hand shell gives rise to the popular name "hermit crab", by analogy to a hermit who lives alone. Several hermit crab species, both terrestrial and marine, use "vacancy chains" to find new shells: when a new, bigger shell becomes available, hermit crabs gather around it and form a kind of queue from largest to smallest. When the largest crab moves into the new shell, the second biggest crab moves into the newly vacated shell, thereby making its previous shell available to the third crab, and so on. Most species are aquatic and live in varying depths of saltwater, from shallow reefs and shorelines to deep sea bottoms. Tropical areas host some terrestrial species, though even those have aquatic larvae and therefore need access to water for reproduction. A few species do not use a "mobile home" and inhabit immobile structures left by polychaete worms, vermetid gastropods, corals and sponges.


Secondary coastal zone forest edge, near open flat mineral sands ocean beach. The crab was originally nestled in a Pandanus sp. tree about a meter from the ground.


I moved the crab to a nearby driftwood log to take advantage of the better light and then let it be...

2 Species ID Suggestions

CandiceB 8 years ago
Hermit Crab
Hermit Crab
Coenobita brevimanus Coenobita brevimanus

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28 Comments (1–25)

Scott Frazier
Scott Frazier 8 years ago

Thanks Ashish for the family suggestion, and thanks Gerardo for the species suggestion. The range includes "southwest Pacific" so I suppose that would take in northern Papua. Indonesia is a vast archipelago. Perhaps it is possible to ID the hermit crab with shell on. I'll tentatively go with the genus and will certainly keep this species in mind as I look further into it. "There are many ways to tell the species of your hermit crab. Eyes, claws, antennae, shields and legs are probably the most common. Looking at all of them together is obviously the most accurate way to tell." Again thanks! Thanks Jolly for your compliment!

Jolly Ibañez
Jolly Ibañez 8 years ago


Gerardo Aizpuru
Gerardo Aizpuru 8 years ago

I´m pretty sure is a common Indonesian hermit Crab
Coenobita brevimanus check this one Scott!

Ashish Nimkar
Ashish Nimkar 8 years ago

May be in Coenobitidae family.
and this site may help you..

Ashish Nimkar
Ashish Nimkar 8 years ago

Seen in drawing look alike your...

Scott Frazier
Scott Frazier 8 years ago

Thanks for your suggestion, but please note that the common name you suggest was already in use for this spotting. Please use suggestions to provide a different common and or scientific name for a spotting species. Thanks

achmmad 9 years ago

Hahaha. Funny spotting!

Scott Frazier
Scott Frazier 9 years ago

Thank you all very much!

SeanWeekly 9 years ago

Great Shots Frazier, he almost looks too big for the shell ha ha

Hans.New 9 years ago

These are very incredible pictures.

alicelongmartin 9 years ago

Like your text and new photos, Thanks!

Hema 9 years ago

What a beautiful shell and extremely interesting information!! Thankyou!

Scott Frazier
Scott Frazier 9 years ago

Added text and more photos!

Ashish Nimkar
Ashish Nimkar 9 years ago
Ashish Nimkar
Ashish Nimkar 9 years ago

Look to be one of following Genus...

Ashish Nimkar
Ashish Nimkar 9 years ago

Hi Frazier... Where find this Hermit crab..there is rich bio diversity of coast line... Hope you get more spotting around there...!!
Great spotting...!!

Cadi 9 years ago

Oooh, I love the colors in this one; its so earthy but yet so bright!

CoraVajnai 9 years ago

wow never seen anything like it!

Scott Frazier
Scott Frazier 9 years ago


Noe and Pili
Noe and Pili 9 years ago

Wow! I love the second pic

Nadi88 9 years ago

Looks really strange!

PatrickJamesTwohig 9 years ago

High fives for Arthropods!

Scott Frazier
Scott Frazier 9 years ago

Thanks all!

LarsKorb 9 years ago

again great catches!

Harsha Singh
Harsha Singh 9 years ago

It's beautiful!

Scott Frazier
Spotted by
Scott Frazier


Spotted on May 10, 2011
Submitted on Jul 21, 2011

Spotted for Mission


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