Hermit Crab Cannibalism Discussion

From archive post “new crab killed”

Jsrtist wrote:
One of my newer E additions was dead when I came home today. Big Calico Crab was eating what was left of him in his shell, sitting up on the surface, and various bits and pieces were scattered around the tank. I know it wasn’t a molt, because the pieces I found were not exo. Also, I am sure I just saw this little guy up and about last night, eating and doing just fine. I am devastated because it was one of my new rescues and he was doing so well!

What possesses crabs to kill others who are seemingly fine? In the past I’ve experienced this with a couple molters. I am wondering if Big Calico is the culprit, because I believe she is the one who killed Mossy this summer (my female who laid eggs). But she has never been a seemingly aggressive crab and I’ve had her for 2 or 3 years now.

I have a 60 gallon crabitat with about 20 or so crabs in it (not quite sure). They have tons of climbing room, surface area and digging space. They get a variety of foods and have filtered pools. If the tank is healthy enough for them to breed in then something must be right. I’m just trying to solve this mystery. Sad

Here’s a pic of my poor sweetie from just the other day:


Salsashark wrote:
The subject says New Crab, how new was your little E? Had he been in Iso, how long had he been in the big tank?

quick draw wrote:
First I am sorry for the loss of your E. It was a little cutie as all hermies are. crying
I had an E simply vanish and I suspect it was eaten (I know it didn’t escape.)

I strongly suspect Gary, my E that is somewhere between the size of a marshmallow and a golf ball. He seems to be the “head honcho” in my crabitat. This suspicion was verified when I decided to put my 5 larger crabs in with all the others. Every one got along just fine except Gary. He kept trying to pick a fight with one purpureus crab that is about twice his size. All the larger crab did when Gary tried to attack was knock him backwards or spin him around…and Gary kept going after him.
Now all is fine. I can only assume Gary got tired of getting his “rear” kicked.
Gary is the sweetest most gentle crab to me.

Jsrtist wrote:
My Big Calico is kind of like your Gary. She is about golf ball sized and sometimes knocks other crabs around (even equal or bigger than her). Then she simply leaves them alone.
The new E had been in for about a week. I don’t iso new crabs anymore; at one time I did. I am familiar with the store I get them from, and had watched this batch for a long time. I’ve ended up bringing most of this batch home. I inspect and SW dip all new crabs against parasites.
All the other crabs I’ve brough home from this batch are thriving-eating, digging, switching shells! I am inclined to believe (and hope) that it was a one time freak incident. A sad incident, regardless.

Ladybug15057 wrote:
jsrtist may I ask if Big Calico has molted recently? I would like to ask all who have unfortunately had hermies mutilated to please note when the mutilation occured and all hermies who were seen eating, or with, or around the one who was mutilated. Those who were seen, with, or eating parts of the mutilated hermie, please do note if they molt in about a month of the occurance, or burrow for a molt.

Jsrtist wrote:
What an interesting question and thought, Ladybug. She has not molted recently that I know of, and she is my most outgoing crab, always out and about so I notice her absence.

I will definitely keep track of whether or not she molts in the coming month. What do you think that’s related to? Do they suddenly need more meat in preparation for a molt? That would make sense!

Aurelia wrote:
One knows they need more calcium before and after a molt…
A few days ago, I prepared fresh prawn that I steamed and crushed with it exoskeleton, and gave it to my hermies (with other food). The hermies who ate the more was 2 premolters. They have been burring for 3 days now and I suspect them to being molting. In all my tank there are cuttlebone and sand dollars and I also crushed cuttlebone on the food I give daily. But this prawn was a calcium supplement, in fact…
As I don’t know who attacked baby Sydney, I can’t tell if there is a relation ship between this attack (20 day ago) and my 2 molters… but baby Sydney has been attacked twice in 4 weeks, and the first time was some hours after he digged out from his molt. He was very weak at the moment. The second time, when he has been severely injuried, I haven’t seen who attacked and ate him.

Ladybug15057 wrote:
A couple years ago there were molters/premolters being found mutilated. (back when my daughters Krabby was attacked when she did a surprise molt in the main tank and when we came home found Shilo on top of her still pinching at her within her shell even though her new large cheliped was ripped off and there were a couple other hermies eating at her shed exo) Shilo and the couple others had molted within the month of being seen eating at Krabby.

From Stacy Griffith

Hermit crab attacked during molt by my Viola- Big pincer was mutilated

Hermit crab attacked during molt by my Viola- Big pincer was mutilated