unknown things .. !

Hello all

Can someone tell me what are these? Are they corals? Weeds? Algae? And are they good or bad?

https://www.dropbox.com/s/i2fh7vqhbliu74d/2013-10-13 16.36.51.jpg?m

Also I noticed that one of the crabs has disappeared for a few days, then I found this at the corner of the tank, looks like a claw ... theres no way he died and left only a claw, or did he fight with the other crab and lost a limb ?

https://www.dropbox.com/s/dhgt1t4m0wnscvz/2013-10-13 16.37.08.jpg?m

 

The first looks like a whole bunch of Majano Anemones, which are bad. Is it only on one rock?

The crab could be molting and in hiding.

 

I agree with cam, those appear to be invasive anemones. Its gunna be a battle. Search the forum for the best methods to get rid of them. A syringe of lemon juice in the mouth has worked for me.

As for the crab, if its a larger hermit, like an electric blue, you will be seeing claws for months after they molt.

 

The one at the front looks like an Aipstasia Anemone and the other looks like it could be a Majano Anemone. Both are undesirable because they sting corals and will spread out of control in the tank. Whenever I see any Aiptasias or Majano anemones in my tanks, I inject TM Elimi-Aiptas directly into the stalk as opposed to into the mouth. I find that the product has a better kill rate when injected into the stalk rather than the mouth.

 

One of the fish has gone missing! It was there in the morning just 4 hours ago.. It's the tiniest one, I'm starting to suspect the 3 crabs in the tank have formed some sort of gang to capture small fish and eat them..

 

It's possible if you have predatory crabs, or even simply hungry crabs.

What species of crab(s) are you referring to?

Do you feed them, or let them scavenge? Remember, crabs are OPPORTUNISTIC OMNIVORES, which means that if they're hungry, they won't pass up an easy meal, such as a sleeping or ailing fish.

Have you checked your overflows, sump, and/or the area around your tank for the fish or its remains?

What kind of fish was/is it, and what are its tankmates?

 

Regarding feeding, I just put the normal fish food but add more than usual so they have left overs to eat (flakes + pellet food). There are 2 hermit crabs which I added myself, but the hitch hikers vary in size and color. From 1 cm long to 4 cm, one is blue, one is dark red, the others kinda gray color. I can always see them turning over the pebbles eating, or hiding under rocks or between openings in in the live rock.

I looked for the fish in the places you mentioned but it's no where to be seen. This happened before as well with another small fish but that one disappeared within 24 hours of adding it to the tank