Big vs. little, possible different species too...

[Kristina]

Hi all, first post here, hopefully I will get some help!

My sister bought two Hermies from a flea market (I know, bad idea) back in August or so. She quickly lost interest and they went without food and water for days at a time. So I stepped in and took over their ownership and care!!

One of the original crabs ended up dying. He was likely unhealthy from the beginning as he never really was active and died shortly after getting them. So then we had one...

Even after getting proper care etc, the original crab was not active whatsoever. He would basically stay in his coconut shelter constantly. I would smooth out the sand to see if he was even coming out for food/water, and would see a single trail to the food/water and back to the house. He never came out!!

So I decided maybe he was lonely and needed a buddy. I went to Petsmart and looked in the Hermit aquarium. HOLY SMOKES. The crabs were running around, digging, climbing, all over the place... very happy/healthy looking... however, they were also HUUUUUUUUGE compared to my tiny little crab! I have no idea where else I would get hermits around here, so I bought the smallest active ones I could find.

There is still a massive size difference between them. They must be different species - I am going to make a post in the species section to try and figure that out.

But... basically what has happened is the little one is TERRIFIED of the big one. If they encounter each other, the little one freezes and then will walk backwards as the other walks forwards, or all out runs away. I've never yet encountered the big one being aggressive as far as I can tell, he almost seems to ignore the little one for the most part.

Just in case, I covered the door of the coconut hut with a shell in a way that only the small crab would be able to squeeze in... in case he needs to get away. I made a seperate shelter for the big crab, and they stay in their respective corners.

Today I was cleaning out the tank, and I put them both in a plastic bowl while I did it. Not five seconds after I put them both in there... the big crab literally JUMPED onto the little one, who was clearly petrified! He latched onto him... I quickly intervened and scared them both back into their shells and put them in seperate bowls. Eeps!

I also recently noticed that the big crab is missing the tip on one of his legs. I'm not sure what that may be from, but he spends almost all night climbing the roof of the cage and he sticks his feet through the slats, so that might be it...

Should I be worried about these two? I don't want anything bad to happen to the small guy!

[erikleeson]

Well first off, welcome to HCP! Hope you find what your looking for!

Now, although very possible it is unlikely the crabs are different species. In the US only two species of crabs are usually sold everywhere; C. clypeatus and C. compressus (Purple Pincer and Ecuadorian.)

Other species are occasionally sold but not nearly as often as the ones I listed.
C. rugosus
C. cavipes
C. violascens
C. perlatus
C. brevimanus

You can identify a Purple Pincer by its round eye stalks and purple large claw. Ecuadorians can be blue, brown, orange or tan or a mixture of the both. Ecuadorians (or as we call them, E's) also usually have a large claw the same color of the rest of the body. There are exceptions of E's with mottled colors which we call calico E's. The best way in my opinion to identify an E is to look at the eye stalks. E's have elongated eye stalks, Purple Pincers (we call these guys PP's) have round and shorter ones.

Posting pictures is the best way to identify a species of a crab! Try and get pictures of the entire crabs body and the big pincer.

If you don't know how to post pictures yet, click here

Now as far as aggression goes, I would say there is nothing to worry about. It is highly unlikely the crabs are fighting because they do not like each other, in the wild hermit crabs live in large colonies and constantly have what we think are fights but are really just small competitions to determine the leader of the group. When you add a new crab to the tank it will usually go up to the crabs and wave its antennae very fast and the other crab will join. They also sometimes start pushing each other over. I can assure you this is not fighting, they are just trying to determine the "alpha crab"

However, the crabs could be fighting but highly unlikely in your case. Hermit crabs are willing to fight another crab for its shell. They will attempt to evict the crab right out of its shell and move right in. This probably isn't your problem due to the drastic size differences.

Now, please post pictures or find out what species your crabs are. All sizes, genders and species can be all housed together. Just make sure each crab has its own space. All hermit crabs should have a "buddy" of the same species in the tank. eg. its not a good idea to house one PP and one E. If this is your case get another PP and another E.

Hope this helps
Have fun at this forum!

[ladybug15057]

Where as in the wild all sized hermies do live together, and in harmony there is a pecking order as well. In the wild most times hermies do need to fight for shells, food, and water. This aggressive behavior in itself can be harmful/lethal. So when we do get new hermies it is highly recommended to iso the new hermie for at least a week so he can adjust to having shells 24/7 as well as food and water. Should cut back on a lot of the aggressive behavior of the new hermie... no reason to fight for the things he needs to survive. How many shells, and what style of shells do you offer your hermies? As for it not being possible that the larger is not wanting the smaller hermies shell is not so. Hermies cannot tell shell sizes, all they know is another is living within that shell so it must be comfortable. It is not until he gets the resident out of the shell, sizes it up himself and tries to slide his bottom into it does he realize it is too small. By then the other hermie could be harmed, or killed over it because one of the last things a hermie will do (unless experiencing severe stress) is give up their protective shell.
My recommendation would be is to separate these 2, both in properly controlled environments even if it means needing to use a divider and provide both dechlorinated fresh and ocean water with their own food sources and shells as well. Prior to introducing them, in a weeks time give them both a bath together in the same water and introduce them in neutral territory. Observe them closely and if they get along fine they can go to the main tank together, if not more iso time would be in order. When introducing new hermies to each other it is not uncommon to see antenna fencing, or even the pushing with the large pinchers. However, if any large pincher action is noted, as in open claw reaching out for the other... they do still need time alone and another time picked to try to introduce them to each other.

Edited to add:
I forgot to ask how long you have had this new hermie? It is ever so important to help them adjust from PPS. Without helping them to adjust, and leaving them be to destress from all they have been through prior to you buying them most times can be lethal. For the article, please read:

PPS

It cannot be stressed enough how important this is to do.
May I also ask, what do you feed your hermies?

[erikleeson]

I couldn't agree more. With all the stress they go through, they feel that the future will provide more/increasing amounts of stress. This makes them feel that they need to fight for basic needs.

I do not want to sound rude, but are you caring for the crabs properly?
(Many new crabbers care for the crabs the wrong way)

• Do they have a tank at least the size of ten gallons?
• Do they have a deep substrate of sand or coco fiber (no gravel or woodchips) of at least 4 inches?
• Is the sand wet? Or wet in some parts? Or do the crabs have access to large pools of water?
• Do the crabs have fresh and salt water?
• Are they fed fruits and veggies and meats etc... not commercial crab diet?
• Do they have an external heat source? (heat light, Under tank heater)
• Is the tank kept humid? (78% - 87% is ideal)
• Do the crabs have a wide range of shells to choose from of different sizes and types?
• Do the crabs have access climbing areas with shade or low shelters like caves or cocohuts?

Sorry if I drop a bomb on you...

Posting a picture of the crabitat would be excellent!

[ladybug15057]

"Is the tank kept humid? (78% - 87% is ideal)"

Ideal humidity is 75-78%, but anything 82% or higher is a higher potential for a mold/bacteria complication. The air also begins to become too saturated for the hermies to breath properly through their modified gills. (and have been known to blow clear bubbles because of this too)

"This makes them feel that they need to fight for basic needs. "

In the wild they DO need to fight for their basic needs normally. So when we bring them home they still have this natural instinct from their native home... not because we bought them. This is another reason we iso them when we bring them home... to help them adjust to having the items they need to survive.