Nighttime predator?

[ambuncher]

I’ve been reefing for about 7 years. Started with a 30g hex (awful idea), moved to a 40g breeder, and then transitioned to a 90g about 2.5 years ago. For years now, I’ve had fish just…disappear. At first I thought it was me just being a new reefer, or bad parameters, too sensitive fish, etc. And some fish have definitely succumbed to sickness or not eating. But I’ve just had too many fish disappear without a trace. I’ve moved my rock from tank to tank, and I’m starting to think I have a predator in the tank, thats moved with the rock. I know I have a large snowflake eel, and a small marine betta. Which might explain things like a yasha goby disappearing (I know, dumb idea). What i can’t wrap my head around is the bigger fish.I had a 4 inch bicolor angel just straight up disappear without a trace. And then a month later a 4 inch China wrasse. And then a month later a 2.5 inch six line. Lost other dwarf angels, a blue spot jawfish (that one hurt), and large wrasses. It’s just too weird. It’s happened for years, every month or two, fish just go missing. I don’t think it’s the marine betta or the eel, since 1) it started happening before them, and 2) they don’t look ‘full’ when the fish disappear like they do when i feed them.

Any thoughts on what’s doing this? I can post current parameters when I get home tonight. But I’d be surprised if it was that,
I am successfully keeping sensitive corals happy like a Goni, and a large clam.

Could I have a bobbit worm? Or something else in there taking down fish? Any suggestions on how to figure that out?

Tl;dr—fish disappear every month, I think something is eating them

 

[WalkerLovesTheOcean]

It's possible you have a predatory worm. What live rock (if any) is in your tank, and where is it from? Do you have a lid? It's possible for a fish to take a jump. Then if you have young children, or pets like a cat and dog, they could move them or eat them. Just some possibilities.

 

[ambuncher]

It's possible you have a predatory worm. What live rock (if any) is in your tank, and where is it from? Do you have a lid? It's possible for a fish to take a jump. Then if you have young children, or pets like a cat and dog, they could move them or eat them. Just some possibilities.

Tons of live rock. Some of it came from
A less than stellar fish store I went to before I knew better. Yep, I have a glass lid that goes all the way around the tank, edge to edge, with the plastic at the back edge. And a canopy over the tank too. So I dont think they are jumping. No children, I do have two dogs though. That’s a thought that they are eating them. The tank is pretty tightly sealed, I’ve checked numerous times since I don’t want the eel to jump. Any thoughts on what type of worm it could
Be?

 

[WalkerLovesTheOcean]

Tons of live rock. Some of it came from
A less than stellar fish store I went to before I knew better. Yep, I have a glass lid that goes all the way around the tank, edge to edge, with the plastic at the back edge. And a canopy over the tank too. So I dont think they are jumping. No children, I do have two dogs though. That’s a thought that they are eating them. The tank is pretty tightly sealed, I’ve checked numerous times since I don’t want the eel to jump. Any thoughts on what type of worm it could
Be?

If you have a lid, then I doubt they are getting eaten by the dogs. It could be lots of things. Bobbitt, onone fugida, ribbon worms, etc. It also doesn't have to be a worm. It could be a crab, or mantis shrimp. Do you hear any clicking noises when you are around the tank?

 

[shakacuz]

do you have an extra webcam, or something similar that is able to record with the lights off? very likely you have something eating or attacking the fish at night.

 

[Jay Hemdal]

I’ve been reefing for about 7 years. Started with a 30g hex (awful idea), moved to a 40g breeder, and then transitioned to a 90g about 2.5 years ago. For years now, I’ve had fish just…disappear. At first I thought it was me just being a new reefer, or bad parameters, too sensitive fish, etc. And some fish have definitely succumbed to sickness or not eating. But I’ve just had too many fish disappear without a trace. I’ve moved my rock from tank to tank, and I’m starting to think I have a predator in the tank, thats moved with the rock. I know I have a large snowflake eel, and a small marine betta. Which might explain things like a yasha goby disappearing (I know, dumb idea). What i can’t wrap my head around is the bigger fish.I had a 4 inch bicolor angel just straight up disappear without a trace. And then a month later a 4 inch China wrasse. And then a month later a 2.5 inch six line. Lost other dwarf angels, a blue spot jawfish (that one hurt), and large wrasses. It’s just too weird. It’s happened for years, every month or two, fish just go missing. I don’t think it’s the marine betta or the eel, since 1) it started happening before them, and 2) they don’t look ‘full’ when the fish disappear like they do when i feed them.

Any thoughts on what’s doing this? I can post current parameters when I get home tonight. But I’d be surprised if it was that,
I am successfully keeping sensitive corals happy like a Goni, and a large clam.

Could I have a bobbit worm? Or something else in there taking down fish? Any suggestions on how to figure that out?

Tl;dr—fish disappear every month, I think something is eating them

I've had reefs with huge bobbit worms and never lost a healthy fish to them. However, it is very common for a fish to die from some other reason, up in the rocks and then be consumed by worms or other CUC, and you may never find a body. Fish also jump out and can dry up pretty small, but careful searching will find a body.

My guess is that there are multiple issues here, with the fish dying from different causes and then the CUC eating them hides the evidence.

Bluespot jaws are VERY delicate in tropical reefs (they need cooler water) but the wrasse and angels dying points to something else. One thing that can happen is a fluke infestation - these worms don't kill fish fast like ich or velvet does, and the fish will show subtle symptoms, and die over a period of time, as opposed to all at once. Also, with flukes, the species of fish affected depends on the type of fluke, so you can run into issues where some fish die over weeks/months due to the flukes, but any resistant fish seem fine.

Jay