Did I kill my sand-sifting goby?

bryan3536 · Mar 12, 2018

I have a relatively new 180g tank. It cycled, then I added 2 chromis, and 16 members of the CUC. All was well, so about two weeks later (and two weeks ago), I added a sand-sifting goby and a blenny. They had been doing well too, and the sand-sifter was an active guy that would sift and go after the misis shrimp I was feeding the tank. I didn't see him after about noon on Saturday, and on Sunday morning we found what was left of him in the hands of a larger member of our CUC.

I figured whatever he wasn't getting from the sand he would be getting from the feedings, but now I'm wondering - did I kill him by putting him into a relatively new tank?

eatbreakfast · Mar 12, 2018

If he was eating when you fed, it was something else that did him in.

larangcon · Mar 13, 2018

How's the blenny doing?

bryan3536 · Mar 13, 2018

So there have been developments, and there may have been a second fatality. The timeline:

Everything seemed hunky-dory on Friday night.

On Saturday afternoon, I added a yellow coris wrasse and a blue-green chromis to the tank. That was when I first noticed that the Goby was MIA, but I didn't think much of it because he frequently slept under a rock during the day. I don't think his death and the new fish are linked.

On Saturday night, I tested all of my levels over beers with my buddy, again, before I became aware of the Goby's demise. All was perfect (which surprised my buddy, since this is a pretty new tank). Only outlier was calcium, which was a bit high (559). We suspect that is just all the new "dry rock" I used.

On Sunday morning, Goby go bye bye. Hermit crab had him 95% eaten, I let him finish. I fed rest of the fish, everyone ate, including the new wrasse.

Yesterday morning (Monday) I notice the new wrasse is MIA. Still MIA last night, after a flashlight search into the rock. Still MIA this morning. Re-tested levels last night, all good. I also unplugged/plugged my heaters and skimmer, didn't get a reaction out of the fish so I think I can rule out stray current.

The wrasse could just be hiding - it's a new tank, and if it was stressed, maybe its in the sand somewhere.

If it's dead, then this is turning out to be a real who dunnit. I'm kind of narrowing the suspect list down to . . . one of my chromis. It's bigger than the other two, and it's become really territorial in the middle of the tank. At this point I basically I have one chromis hiding in the rocks on the left, one hiding in the rocks on the right, with the jerk chromis in the middle keeping them there. The blenny does his own thing and is ignored by the Chromis.

bryan3536 · Mar 13, 2018

larangcon said:
How's the blenny doing?

Blenny is fine.

eatbreakfast · Mar 13, 2018

Yellow coris wrasses can stay buried for an extended period of time. And they also can take time to get their circadian rhythm synced up with our time. I wouldn't worry yet.

bryan3536 · Mar 13, 2018

eatbreakfast said:
Yellow coris wrasses can stay buried for an extended period of time. And they also can take time to get their circadian rhythm synced up with our time. I wouldn't worry yet.

I didn't think of that. My tank is definately off from LFS - probably 6 hours delayed at least. Maybe jetlagged. THanks.

bryan3536 · Mar 13, 2018

eatbreakfast said:
Yellow coris wrasses can stay buried for an extended period of time. And they also can take time to get their circadian rhythm synced up with our time. I wouldn't worry yet.

Ding ding ding! The wrasse came out of hiding sometime this afternoon, per my 8 year old son. Was swimming around with my suspected killer chromis (sorry for the accusation bud) and ate mysis during feeding this evening. Was simultaneously happy and angry - I spent hours last night trying to trouble shoot a problem that probably doesn't exist. Thanks all for your suggestions and help.