Crab Id Help Needed

[Tongue_Flicker]

 
Need help. So apparently this crab is neither a moon crab (geocarcinus quadratus) nor a patriot crab (cardisoma armatum) as I have thought for the past couple of years
 
could you guys help me identify what my crab is??
 
 
Note the white pincer with a gap
 

 
 
The spines are more like soft bristles and not algae.
 

 
 

 
Thanks!

 

[Chad]

I love crabs and that's a great one! 
I can't identify it by sight but have some resources at home I can flip through. I am partial to crabs.
 
Totally throwing out a guess I would say Cardisoma carnifex which is a coastal crab. http/www.projectnoah.org/spottings/8909453
 
Can you tell me a little about it it? Is it land, freshwater, brackish?
Is it a female?
 
I agree that it's not either one of the species you mention above. The claws are wrong for that even given differences in gender. 
 
I'm wondering if it's a female of a species where the mail has a asymmetrical claws. 

 

[LyraGuppi]

Omigosh nightmare fuel! (1st pic)
 
Can't help, but just wanted to say you have a lovely crab!

 

[Tongue_Flicker]

Its carapace is kinda rough and edgy as compared to C.carnifex smooth and rounded carapace. The females have the same white claws only smaller. Unfortunately their claws are not dimorphic as with the majority of crab species. The only sure way is to check their belly flap, gills as you may. Males have triangular to pointy gill covers while females have wide and rounded gills. Their overall adult size can sometimes tell the difference since females tend to be smaller as well. With that said, this one is male

It is freshwater (so I've been told). It has been living with a huge water bowl of freshwater for the past 2 years so i guess it is. It dips in water during noontime or during the brightest hours of the day but spends 90% of its time on land (or rocks) to feed and just well, hang-out. It is active at any given hour of the day but especially during afternoon hours and is particularly fond of eggplants.

My efforts to ID it has failed over the years as it appears that this species is not popular or virtually non-existent in any hobby -___-

 

[Chad]

Can you post some more photos from different angles? Different lighting etc?
 
I still think it's some kind of Cardisoma.

 

[Tongue_Flicker]

Will do in the few, i'm already in bed lol. The first 2 photos had no flash so the colors were dull. The 3rd photo had flash on so the colors are clearly visible.

But here i got another photo

The shop owner said it is an Asian crab. I read all 4 members of the genus Cardisoma are either in Africa or the Americas.

I was checking out the genus Discoplax, an extracted group from the Cardisoma and guess what I saw a blog in chinese with the photo of the last crab that has 100% similarity to my crab's carapace description but the claws were off though

http/reader.roodo.com/crab_crssing/archives/11151399.html

Might as well research on chinese crabs then lol

Checking the genus Sesarmops now!

 

[Tongue_Flicker]

I think i'm closing in on our mystery crab lol..

Further research led me to this:

Neosarmatium rotundifrons

 

[Tongue_Flicker]

I'm inclined to boil it down to 2 genus

Either Sesarmops or Neosarmatium

Both have consistent carapace color, texture and pattern. Non-dimorphic claws are present. Adult sizes match and the interesting gap between the claws is also unique and occurs in both genus. Plus geographic distribution overlaps. Watcha think, chad? This is team effort LOL! I'm so excited since i never got to be this close to identifying my crab before -__-

 

[Chad]

I think you're right. 
 

I think i'm closing in on our mystery crab lol..

Further research led me to this:

Neosarmatium rotundifrons

 

[Tongue_Flicker]

The purple legs are kinda off though. Mature adult coloration maybe? 'Coz I've seen the young ones and they are red & ivory colored as well.

 

[Tongue_Flicker]

Okay so 100% Neosarmatium sp. but as to what species, morphological differences will only tell. I'm not much of a crab fan but thank goodness for my scorpion background since the anatomical terms are the same.

Found this paper as well. Thought you'd be interested, if ever this crab lands on western shores (or shops lol)

http/www.yumpu.com/en/document/view/12209873/the-sesarmid-genus-neosarmatium-decapoda-brachyura-new-

 

[Chad]

The purple legs are kinda off though. Mature adult coloration maybe? 'Coz I've seen the young ones and they are red & ivory colored as well.

Don't let colors get too much in the way. They can be different based on where the crab is during the molting cycle, diet, location, age, etc. Claw shape, carapace, eyes, legs etc. are solid clues and color you sometimes have to look at several photos of the same species. You will see there is a wide variety of color and can nail it down better. 
 
The paper you linked does highlight a common issue faced when trying to identify crabs: there are lots of species and they often look nearly the same. Like corals it sometimes takes dissection or DNA analysis to really discover they are different.