JMT's crab species evaluation

Post by **JediMasterThrash** » Fri Jul 06, 2007 3:59 pm

I've decided to place the conclusion at the top instead of the bottom, to facilitate quicker reference to this thread. But naturally follow the information in the second half of this post to see where my opinion is coming from. I do not doubt that in the future, this conclusion will change, and I continue to welcome new information.

Ok, so JMT's official opinion is:

American species:
C. clypeatus
C. compressus

Aussie species:
C. variabilis

Indian ocean species:
C. rugosus
C. cavipes
C. brevimanus

West Pacific species:
C. spinosus
C. perlatus

Japanese species:
C. purpureus
C. violascens

Potentially unique variations of rugosus:
C. scaevola
C. psuedorugosus

Defunct species:
C. olivieri = perlatus and violascens
C. carnescens = perlatus
C. longitarsis = Clibanarius longitarsis (marine hermit crab)
C. rubescens = rugosus

Notes:
* When you pluralize the species, change the "us" to an "a", such as "rugosa".
* Species names are lowercase after the capitalized genus.
* Coenobita is pronounced "see'-nuh-bahyt-ah" or "see-nuh-bit'-ah".
* Ecuadorian is pronounced "ek-wuh-dawr-yuhn"
* There are only 12 (or 10, depending on your point of view) species of coenobita, not the 13 still listed everywhere.

It's been several years since I last found and posted this research article. Since then, all my related posts have disappeared off the message boards and I could never find them again, and have had to try to remember the details out of memory.

But I found it again:
http://www.nhm-wien.ac.at/NHM/3Zoo/PM_PD.pdf

And here's the skinny:
C. olivieri is defunct. They were misidentified perlatus and violascens
And these specimins of C.olivieri were misidentified spinosus:
http://decapoda.free.fr/fiche.php?sp=185

However, I think we may have been wrong about C. scaevola. They are reminiscent of white ruggies, and we originally said the scaevola were misidentified rugosus. However they appear to only live on the siani penninsula, and are specifically adapted to very dry, hot desert conditions on those beeches
http://www.int-res.com/articles/meps/25/m025p189.pdf
The only known picture of a scaevola that floats around is a picture of a variabilis, so really we have no known pictures of a scaevola to make an identification from. My assumption is that the look similar to white rugosus, if they are not in fact just rugosus.

There are listed variations of rugosus (and as anyone who's had a few rugosus knows, there seems to be some variations, like the darker greener harrier, versus the lighter, neon ones, however, my rugosus always seem to change color every molt). This site references a variation granulosa.

Additional non-unique species that are probably rugosus includes rubescens and pseudorugosus (rugosus understandably would have initially had several different species attributions due to the vast variety of hair and color variances. Only now that we keep them captive can we observe that these variations are caused by diet and growth).
http://coenobitaresearch.blogspot.com/2 ... -info.html

But pseudorugosus, like scaevola, is still today regularly referred to as unique from rugosus, so it's possible that at least to scientists they are unique, even if we can't yet tell the difference (it would help if we had pictures!)
http://www.int-res.com/articles/meps200 ... 38p163.pdf

Additionally, while originally C. variabilis is actually C spinosus var. variabilis (a variation of spinosus), it appears that initial discovery misidentified juevenile spinosus as a different species, and called them variation variabilis. But now we know that this specimins were just young spinosus, and the other newer specimens were given the name variabilis. The crabs we now know as variabilis are too different from spinosus (though you can see similarities in stucture) to be classified as a variation in my opinion. Both spinosus and variabilis are aussie crabs.

C. carnescens are misidentified juvenile perlatus.
http://decapoda.free.fr/fiche.php?sp=183

Initially, a lot of brevimanus specimens were misidentified as clypeatus, until they were given their unique species ID.

C. longitarsis only has one ID from a hundred years ago, and was never IDed again. It's from the east indies, so it probably was just what later became known as a cavipe.

However, I found a reference to claiming to questioning whether longitarsis was terrestrial, since it was from an indonesia river, and found this site:
http://www.duniasatwa.com/forums/showth ... 316&page=2
Which seems to confirm that longitarsis is a marine hermit crab, and is not terrestrial. And we finally have a picture of a Clibanarius longitarsis!

troppo · Post by **troppo** » Fri Jul 06, 2007 5:52 pm

Wow, we have Spinosus here in Australia?

I only thought there was variabilis and perlatus.

Post by **JediMasterThrash** » Fri Jul 06, 2007 7:47 pm

You should be able to find spinners on the north-eastern coast. However, I've decided to reclassify a few as west-pacific instead.

My location classification's are just meant to help logically group some species together. It's not a substitute for the list of official lands and islands the species have been collected from.

troppo · Post by **troppo** » Sat Jul 07, 2007 6:00 pm

I'm on the north-east Australian coast

Wow, will have to find some piccy's of spinosos so I can see what they look like.

tonycoenobita · Post by **tonycoenobita** » Tue Jul 10, 2007 11:16 pm

Very Nice!!!! I also have some idea (in red). What i think is:

American species:
C. clypeatus
C. compressus

Aussie species:
C. variabilis

Indian ocean ~West Pacific species:
C. rugosus
C. cavipes
C. brevimanus
C. perlatus
C. violascens
C. spinosus

Japanese species:
C. purpureus
*Japan also have also found C. rugosus ,C. cavipes ,C. brevimanus ,C. perlatus ,C. violascens ,C. spinosus(this may be non-native species)

Potentially unique variations of rugosus:
C. scaevola
C. psuedorugosus -> or in fact a juvenile of C. perlatus?

* There are only 12 (or 10, depending on your point of view) species of coenobita, not the 13 still listed everywhere.
>But I think Birgus latro is also a group of Coenobita, so 13 is ok.

Guest · Post by **Guest** » Sun Jul 29, 2007 6:27 pm

No, Birgus latro is not part of the Coenobita genus. If it were, it would be C. latro, not B. latro. However, both the genus Coenobita and the genus Birgus belong to the family Coenobitidae. The similarity in the seplling of the genus Coenibita and the family Coenobitidae can get confusing at times.
All hermit crabs belong to the genus Coenibita. That's why you always see 'C.' at the beginning of all the species names. Birgus latro is definitely related to hermit crabs, but not closely related enough to go in the same genus, so it gets put in a different genus in the same family. However, because Birgus is a separate genus, I don't think I would consider coconut crabs as a type of hermit crab, just a relative.