Mystery Crab and Clownfish disappearance

[SaltyNewbie]

I started this topic under the "gorilla crab" thread, but I didn't want to hijack the post, so I started a new one here.

Basically I've had a mystery crab in my tank for 10 months now. He has been slowly getting bigger, but has never bothered anything. He has mainly white body with a brown streak on his back, brown stripes on his legs, and dark brown claws. He looks somewhat like a emerald crab, but he has no hair. His main shell is about nickel sized. The picture is a very crude drawing of what he looks like.

Recently, one of my percula clownfish (that i've had for about 1.5 years) suddenly disappeared. I have checked all around the tank to make sure he didn't jump out. I moved some of the LR around to see if I could fine something left of him. So far I have come up with nothing.

Here is what is in my tank:

29 gal, fluval 204, JBJ PC 10000k daylight and 7200k Actinic, Prizm Skimmer, 1 powerhead, 35 lbs of mainly Figi LR, CC base, 1 yellow tail damsel, 1 percula clown (used to be 2), 1 flame angel, 1 sebae anemone (which recently died too after 1.5 years. I think its because I waited to long to change my bulbs, he had not really been expanding for about a month), 2 camel shrimp, 1 debelius reef lobster, 1 green brittle star, several snails, 1 red hermit crab, 5 blue hermit crabs, and the mystery crab.
Ammonia has a very SLIGHT reading, nitrate has a very SLIGHT reading, nitrite is 0, alkalinity is normal, salt is 1.0245 or 33 ppt, and my ph is 8,6 (its always been this high and I can't get it down).

I am 100% positive the brittle star did not eat the clown. He is also way too lazy to ever try and catch anything himself. So I figure either the lobster or the mystery crab got him. The lobster has always stuck to himself though and is mostly afraid of the fish. I think this myster crab might also be the reason I keep losing so many snails.


Any thoughts to what is happening here or advice on what to do???

I would like to go buy another percula clown soon because the one I have is stressing out big time since she lost her mate and her anemone all in a week. Would a rose anemone or sebae anemone be my best replacement? Also, any recommendations on what to add/do to the tank.


Thanks in advance.

Brett[/img]

 

[SaltyNewbie]

Anyone? I tested the water again today. Everything is good. I also added some carbon in the filter in case something was floating around in the water.

Tomorrow I am definately going to go buy another clown. I don't think "Hoops" can take this alone stuff anymore. I might get an anemone while I am at it. I still can't decide between the sebae and rose anemone.

 

[Juck]

My money is on the lobster but I wouldn't trust that crab either. I'd remove both,,, fish are easy prey when they're sleeping. I think your ammonia spike could be caused by the remains of the clown decomposing somewhere out of sight.

I don't know the wattage of your lights but a tank-raised BTA would probably do much better than a Sebae in your tank.

Good luck with your new Perc. Was the fish that died the male or female?

 

[SaltyNewbie]

I was thinking that I'd set up a ten gal with some live sand and rock, and throw the crab in there, but after seeing him attack my turbo again tonight..... i think hes a gone. Anyone in SW ohio want this crab? I'll check and see if the LFS wants it. I really don't want to kill the guy.

I am going to hang on to the lobster for now and see if I have any more problems.

I probably will go with the BTA. I just hope the clowns like it. The clown that died was the male (he was significantly smaller than the one left).

Is there any problem with putting two rose bulb anemones in the same tank????

I have a power compact lighting system that has two 65watt bulbs. So 4.5 watts per gal will hopefully be enough.

Thanks for the reply.

 

[wade1]

If you know where the crab lives, you will likely find a large pile of snail shells around the area.... I left one of them in my tank for a couple of years, knowing it took a snail once in a while. Come to find out, there were better than 3 dozen snail shells piled up around its burrow!!

One good way to check the habit of the crab is to look at the 'cutting' surfface of the claws. If it is an herbivore primarily (note that all crabs will eat what they find) it will have flattened 'pads' on the inside ends of the claws. Meat eaters have sharper or pointed claws in general.

Sounds like you have a good plan at least.

 

[SaltyNewbie]

Well when I got home from work today my big turbo snail had been eaten. I finally broke down and removed most of my LR until I found the bastard. He was deep inside one of the pieces of LR eating what was left of the snail. I eventually got him out of the LR and took him to the LFS. They called him a "monster crab". They said they are known to eat fish and snails. They ended up giving my $5 for him which was cool. I also bought a real small percula clown so the other has a mate now. I also bought a rose anemone which is gorgeous. Thats all for now. :?

 

[HClH2OFish]

That was really cool of the LFS to do that....

And sorry to hear about the loss of you clown