Who is murdering my wrasse?

eraserhead187 · Feb 22, 2020

This is twice now. First was a six line, this time it was a flasher wrasse. Both times, it happened during the middle of a three day blackout to control cyano. I took the cover off to check stuff out, and there was the skeleton and fins of the poor guy. First time was a few months ago. I know that these wrasse kind of sleep in little nooks they find under rocks, so I am suspecting some type of evil crab or shrimp. I've just got hermits and one coral banded shrimp. Nothing else that it really could have been. Other inhabitants are a pair of clowns that keep to themselves, a royal gramma, and a banggai cardinal. Hardly a crew of killers. The tank is a 29g biocube. Parames are 1.025, 0 ammonia/nitrite, 15 nitrate, 55 phosphate, 78 degrees.

Gareth elliott · Feb 22, 2020

How large is the coral banded shrimp? They can catch small fish, if small enough their claws aren’t exactly huge. And ive never personally seen this behavior myself, only anecdotal through other peoples threads. My CBS is barely visible let alone bothers fish.

eraserhead187 · Feb 22, 2020

He's actually pretty massive. I haven't seen a lot of them as big as this guy is.

Indytraveler83 · Feb 22, 2020

Have you ever used a red light at night to view your nighttime crew? It's crazy what hitchhikers you can pickup on accident.

eraserhead187 · Feb 22, 2020

Blackout with flash, so it looks weird.

eraserhead187 · Feb 22, 2020

Indytraveler83 said:
Have you ever used a red light at night to view your nighttime crew? It's crazy what hitchhikers you can pickup on accident.

I have not. I shoyld probably do that though. Especially since there is some strangeness afoot.

saltyhog · Feb 22, 2020

I would be surprised if it's the CBS. I have 12 wrasses, some that sleep within inches of his cave and haven't lost one in years (about 4) that I've had him.

Indytraveler83 · Feb 22, 2020

eraserhead187 said:
I have not. I shoyld probably do that though. Especially since there is some strangeness afoot.

It may give you some clues. Could be something that comes out at night.

Also wonder if the wrasse are dying for a other reason and just being eaten once dead? Could the blackout be affecting O2 levels, or are you treating with something that the wrasse might be sensitive to?

eraserhead187 · Feb 22, 2020

saltyhog said:
I would be surprised if it's the CBS. I have 12 wrasses, some that sleep within inches of his cave and haven't lost one in years (about 4) that I've had him.

I have never seen him do anything aggressive ever. And it's not like he has giant pinches, those things don't look like they could grab anything!

eraserhead187 · Feb 22, 2020

Indytraveler83 said:
It may give you some clues. Could be something that comes out at night.

Also wonder if the wrasse are dying for a other reason and just being eaten once dead? Could the blackout be affecting O2 levels, or are you treating with something that the wrasse might be sensitive to?

I'm not treating with anything, and I have a skimmer running and the tank is well ventilated so I would be surprised with O2. Everybody else is totally happy!

TheShrimpNibbler · Feb 22, 2020

Is your rock live rock, or did it start out dry? If it started out live, there could be something like a gorilla crab or a mantis shrimp in there.

eraserhead187 · Feb 22, 2020

TheShrimpNibbler said:
Is your rock live rock, or did it start out dry? If it started out live, there could be something like a gorilla crab or a mantis shrimp in there.

That actually could be. It's a big mixture. 75% was dry, a few pieces from my other tank, and then one big old porous piece from a LFS. So that is not out of the realm of possibility. Are they something that looking with a red light may reveal?

MikeyB · Feb 22, 2020

I would put my bets on your CBS. He's killing it and maybe your CuC is picking the body.

I would of never believed that a CBS would grab a fish until a few years ago my old CBS grabbed my female blue throat trigger that was easily more then double his size and held her down for a couple seconds before letting go.

eraserhead187 · Feb 22, 2020

MikeyB said:
I would put my bets on your CBS. He's killing it and maybe your CuC is picking the body.

I would of never believed that a CBS would grab a fish until a few years ago my old CBS grabbed my female blue throat trigger that was easily more then double his size and held her down for a couple seconds before letting go.

Oh wow, no kidding. Maybe I should stay away from wrasses for a while then... My guess is one was sleeping all cozy and just got ambushed.

Indytraveler83 · Feb 22, 2020

eraserhead187 said:
That actually could be. It's a big mixture. 75% was dry, a few pieces from my other tank, and then one big old porous piece from a LFS. So that is not out of the realm of possibility. Are they something that looking with a red light may reveal?

The animals can't see the red light very well, so it gives you a better chance to scan the tank in the darkness before they scurry back into a hidey hole.

MikeyB · Feb 22, 2020

eraserhead187 said:
Oh wow, no kidding. Maybe I should stay away from wrasses for a while then... My guess is one was sleeping all cozy and just got ambushed.

Yep. I was doing something to my tank, i don't remember what, but my wife was right next to me and she saw him actually grab the trigger, sure enough i looked and yep.

If i we're you i would pull the CBS out, but that's your call

eraserhead187 · Feb 22, 2020

MikeyB said:
Yep. I was doing something to my tank, i don't remember what, but my wife was right next to me and she saw him actually grab the trigger, sure enough i looked and yep.

If i we're you i would pull the CBS out, but that's your call

I could toss him in my other tank. The clowns in there are maroons, the female is giant and they are mean as spit. I had a flame hawkish that would slaughter any shrimp or crabs I had, but he must have had dirt on Hillary cuz he suicided a couole months ago. So I can have shrimp in there again.

TheShrimpNibbler · Feb 22, 2020

eraserhead187 said:
That actually could be. It's a big mixture. 75% was dry, a few pieces from my other tank, and then one big old porous piece from a LFS. So that is not out of the realm of possibility. Are they something that looking with a red light may reveal?

Yeah, definitely look around at night with a red light. Do you ever hear any snapping or popping sounds coming from your tank, especially at night?

Michael Gray · Feb 22, 2020

get rid of the CBS and get wrasses.. way better.. get acleaner shrimp..

ScottR · Feb 22, 2020

Not to change gears here, but if you have Cyano, try chemiclean. It will take all the Cyano out fast and you don’t need to do a blackout. It’s harmless.