Suspected homicide...

[Mrramsey]

So this morning I am scanning my tank like i usually do. I have 2 OCC clowns and a yellow tang, about 30 varying snails, coral banded shrimp and 2 emerald crabs. mostly soft corals and 3 GBT anemones.

I spot "Lefty", one of my crabs that only has one pincer, mulling around in some xenia. Then I spot the other crab in the birds nest coral where he usually hangs out in the mornings. I look closer... man this guy has grown. But wait... whats that on the bottom of the tank hidden by some xenia? It's the juvenile emerald crab belly up and dead!

I have had this guy for a few weeks now and he's been thriving. I know sometimes things just die but in this case I believe he was picked off, snuffed out, taken down because in his morning spot sat a brute of an emerald crab to the likes of which I had never seen.

I added only two emerald crabs to the tank. I added two pieces of live rock with corals attached back in June. That is the only way this guy could have been introduced. Almost a full 5 months of which 2-3 months had no live stock whatsoever. I watched this tank everyday and at night no clue he was there.

I guess the two I introduced had drawn this guy out of hiding.

 

[formsix]

Interesting. I don't know *too* much about crabicide, but I do know that we used to have a whole bunch of little gorilla crabs, random crabs that I couldn't ID, and porcelain crabs in the refugium... plus some baby urchins and other small critters. I gave a few porcelain crabs a "reprieve" to the DT, but other than those, well, apparently, there can be only one king of the sump. My refugium has been taken over by one crab who now has a half-dollar sized body and seems quite at home as an only crab!

 

[Mrramsey]

I suppose it could have molted but this guy, as best I can tell at this point, looks to be twice as big as the one that was 'dead'.

 

[formsix]

Hmm, I suppose that could be the case! I don't usually see crab molts in my tank so I don't know how convincing they look -- I know the shrimp ones look freakishly like their old inhabitants, right down to the antennas!!

Now you have to investigate the remnants to solve the mystery!

 

[Mrramsey]

Well I gave it a flush already but gauging the weight of the specimen I am fairly certain it was not just a molt.

 

[pinnatus]

I am going with molted. They grow a good bit after a molt, and the molt is very convincing as a dead crab.

I have been fooled before myself.

 

[Mrramsey]

I am going with molted. They grow a good bit after a molt, and the molt is very convincing as a dead crab.

I have been fooled before myself.

Really? I mean this guy is considerably larger than the "dead" one. Are they some what soft when they emerge from the old shell?

 

[pinnatus]

Yes, but not for long.

 

[Tactical33125]

the same thing happened to me with a sally crab, I saw the full shell and legs all over my tank and im like geez i just bought the pair and 1 is already dead, then the other day i was caught off guard and saw both of them there, the male the one i thought was dead loves to hide all the time doesnt really come out ever.

 

[Mrramsey]

Wow... this is really interesting. I have been googling all over the place this morning. It does seem like it is not uncommon for the crab to double its size after a molt. freaky! It also explains why it is in its usual spot in the birdsnest coral, well protected.

I was having a really hard time believing that I had not seen an additional crab in there for months.

 

[TreyK]

It would be pretty hard to mistake a molt for an actual deceased animal..

 

[pinnatus]

It would be pretty hard to mistake a molt for an actual deceased animal..

No, it is very easy to mistake. When I was 13 (I am 53 now) I had a large crab, it was yellowish in color, and I had it for a long time. One day I woke up and saw a much larger green crab in the tank and my yellowish crab was dead on the bottom. I was wondering who put the large green killer crab in my aquarium, and knew my parents (who were divers) had been diving so I assumed they got me a new crab and it killed my old crab. i was highly upset! It was a molt.