Who is the culprit for killing my cleaner shrimp?

[Aruen]

I have:

2 Clarkii Clown fishes (approximately 3.5-4" and 2-2.5" in size)

1 big Fire Shrimp (always hiding behind the rocks on the left corner)

1 big Boxing Shrimp (always stationed at the highest rock)

1 big Cleaner Shrimp - RIP (stationed on the right corner front of the rock)

King of the tank is the big Clarkii Clown.

I bought the shrimps together recently and as for the Clarkii Clowns, I have them with me for more than 3 years.

Before this batch of shrimps (above mentioned), I bought 1 Cleaner Shrimp for testing to see if the water condition is liveable for Shrimps because I am using a JBJ 12g Nano Cube and the only maintenance is month change of water (nothing else). All seems well as for water condition. One day I found my cleaner shrimp half dead with the bottom half of the body eaten. HOW? One minute it's alive and 1 hr later it's murdered? I suspected the bigger Clarkii.

Then I went along to buy the above batch of 3 different types of shrimps. All seems well and peaceful until today. Same thing happened to the new Cleaner Shrimp. Dead leaving me more confused as both the current and previous shrimps were somehow murdered in the same patterned in broad daylight. They weren't molting so they should not be vulnerable.

Every single day, I spent most of the time watching TV and the tank at the same time to see how my marine friends are getting along. The Clarkii Clowns ignore the Shrimps. The boxing shrimp ignores everyone unless someone decided to go really close to it then it will display its extended claws.

My gut feeling for the murderer to be the Clarkii Clowns. My question is, "Why is the victim always the Cleaner Shrimp?! Oh Why?!"

I feel like buying 2 Cleaner Shrimps this time to test if 2 is better than one to defend against the monkey who killed them. I really like them and want to successfully keep them alive. Should I quarantine the bigger Clarkii for a month or two? But I'm worried it'll get depression confined in a small area in the tank. It loves free space to swim around. I can't have the King dead after having it for these few years.

As for hiding places, I have decorated the live rocks in a way that the bigger Clarkii couldn't invade 90% of private hiding areas.

Anyone knows any Marine Shop that sells livestocks including shrimps closer to town area at a reasonable price now that Reborn is no more? Some shops tend to overpriced to the extent that I could actually get 2 shrimps for the price of one.

All advices will be deeply appreciated!!!

[deltec]

you should try sealife, which is at the balestier area...it always has a good supply of cleaner shrimps.

[vinccc2009]

Ya..saw quite a lot cleaner n fire shrimp there yesterday

[tunicate]

Maybe you have too many shrimps in a 12g.

[TayHongSiang]

shrimps r very sensitive to high nitrate levels and ammonia...probably yr water conditions is not clean...too much nutrients

[Aruen]

Water is good.

The other 2 shrimps been there long enough with no problems. The murdered cleaner shrimp even molted well.

It was definitely killed with half body gone with the 1st victim still half alive.

Do you guys think it is a good idea to quarantine the big Clarkii for a month to see if it's really the culprit?

[Aruen]

Ya..saw quite a lot cleaner n fire shrimp there yesterday

Any big like 3" for cleaner?

[tunicate]

It could even be a hitch hiker in your LR which you've yet to notice. The cleaner shrimp might have been hanging around near to where it's hiding. Unless you don't feed the fish, I don't think the clown is responsible for your lost.

[Aruen]

It could even be a hitch hiker in your LR which you've yet to notice. The cleaner shrimp might have been hanging around near to where it's hiding. Unless you don't feed the fish, I don't think the clown is responsible for your lost.

No crabs. This tank has been cleanse from unwanted critters for 2 years+. I feed the clowns well. Now, I really don't know who attacked the cleaner if it is not the bigger clown!

You see, the shrimp is still moving with the lower part chewed off.... it's a very disturbing image... I've stopped eating prawns. When I see a prawn, images of my shrimps flashes by.

The longest living cleaner shrimp is when I quarantine it for 1mth inside the tank (that's the 1st cleaner).

I think the best idea is to monitor the tank with webcam all the time until something happens but that's too much work. This will be the last resort in the worst case and I really do not want to do this .

[FuEl]

When clarkii clowns mature they become aggressive as they approach spawning age. Not much problem in larger tanks but in smaller tanks they will end up killing everything else, especially in 12 gallons.