Killer Yellow Watchman?

[JJC]

OK, I need some advice here. I have a 27 gallon cube set up as a nano reef tank. It has been going for aprox 8 months. Original stocking was(in order) a cuc, Percula Clown, peppermint shrimp, firefish, and Yellow Watchman Goby. These fish were stocked over a period of three months(one fish a month) after initial cycle. A month after Ywg added my firefish dissapears (yes I have a tight fitting cover). I waited a couple weeks to be sure it was gone for sure. After no sign of the firefish, I put in two small reef chromis. Two weeks later, my peppermint shrimp dissapears. Another two weeks goes by one of my chromis is gone, then another one three weeks later. At this point I am deffinately thinking Mantis. Right? Well, I try all the tricks to find and catch it. Traps, Empty covered bucket for live rock, freshwater soak, club soda over rocks. No mantis found. I didn't add any more fish after trying all that. No problems with my clown or my ywg, which have been ok since the beginning. So a week ago I try a sixline wrasse to go with my remaining fish. Today at feeding time----GONE. Is it at all possible my YWG or my clown could be doing this?

 

[CaptainJugz]

What are water perimeters? Goby is not likely to be the culprit. Why do you think it is the Mantis? It may very well be, but curious?

 

[JJC]

parameters have been fine since addition of first fish. 0 ammonia, 0 nitrite, 8.3 ph, 1.025sg, highest nitrates reach is 5 before each weekly 15% water change. Both the clown and the ywg have thrived since the start. Never noticed any of the fish which dissapeared acting sick. I just assumed since healthy fish just dissapeared overnight, it had to be a mantis, or some other killer hitchiker. No likley offenders turned up while treating live rock, that leaves my two remaining fish....

 

[JJC]

any other suggestions?

 

[Nu-Nu the eel]

What leads you to think its a mantis?? Hear any snapping? Inverts missing? Huge tunnels? In my opinion its not a mantis...

 

[JJC]

there is also a spearing mantis which doesn't snap or click. and peppermint shrimp was second guy missing.

 

[Nu-Nu the eel]

Okay well there has to be a legit reason why you think there is a mantis, i dont really see it. I think you might just be buying weak fish or they are dying and getting eaten. Have you bought any live rock? How much and where from?

 

[JJC]

when I first started the tank up I bought about 40# from a lfs.

 

[scottayy]

Lol I really don't see a YWG doing any killing! Depending on the clown they are semi agressive. But I really don't see that much killing from a clown either.

Hows your flow? Maybe not even relevant but I had a lot of fish deaths before I had any flow in the tank.

Any signs of ich, parasites?

 

[JJC]

no signs of any sickness. I have two korallia 425's aside from my return flow. I thought both reef chromis and sixline wrasse were supposed to be hardy, tolerant fish. That is why I chose them as replacements.

 

[scottayy]

Flow is good. Yeah they are pretty tolerant. But shipping stress takes a toll and a standard pet shop treatment of their fish isn't very nice and their parameters are less than ideal (from my experiences). In my experience also, clowns and ywg are less tolerant than those two species. How did you acclimate?

 

[JJC]

all fish were purchased from same lfs. been buying from this store for 5 years, never had a problem. I am drip acclimating fish over period of 1 hour.

 

[scottayy]

Well shoot. Based on what you've posted everything sounds good! I'm out of ideas. Sometimes fish just die and we don't know why. I hope that's the case here.

Maybe someone else will chime in with something I'm missing. Sorry I'm no help!

 

[JJC]

thanks for trying!

 

[Qube]

Any crabs that are a part of your CUC? I've heard interesting stories about Sally Lightfoot crabs in nano setups.

 

[Beengirl]

Do you have an emerald or ruby crab? I've heard several stories of them grabbing fish at night if they can. Might have one as a hitchhiker if you put in LR.

 

[JJC]

had an emerald at one point(first month of cuc added) . saw what i thought was his molt, but never saw him again. assumed his molt was actually his dead body parts after not seeing him again. I can rule him out though. He didn't turn up when I put my live rock through hell.

 

[CaptainJugz]

Yellow watchman can reak havoc on a DSB and the general condition of a modern reef tank. Emerald crab is generally friendly, but 1+ on the opportunistic aspect of any crab. Had to take apart an entire reef to rid myself of a "yellow watchman gopher." bastards are hungry!!