Dead fish, water is perfect..What gives?

[cytranic]

(Twilight Zone music starts)

Well I've had my first death in my tank. Actually 3....I think..

My tank includes:

Cleaner Shrimp
Mandrin Goby
Yellow Head goby
2 firefish goby
Turbo snails
Hermit crabs

Everything was perfect for a week, everyone was getting along and then one morning I woke up to half of my Firefish goby's tail gone. I know he tried to go into the yellow head gobys lair, and he chased him out but thats the only thing I ever noticed...

Well I found 1 firefish goby dead 2 days ago, and since then I have not seen the yellowhead or the other firefish...Funny thing is, the mandrin is still munching down on his copepods, and the cleaner shrimp is happy as ever..

I also have some mixed pylops, and a elegance coral and they are doing fine..

I'm almost positive the water is perfect, because all my readings (Ammonnia, nirite and nitrates are 0) and my other fish are doing fine..

Could these fish just not have likes each other?

[krackel]

I have heard that firefish put themselves into a "locked" mode at night, even if a bristle worm or crab start gnawing on it, it will stayed locked into whatever hole its in.

[cytranic]

Make sense, the firefish I found was chewed up..I thought hermit crabs got to him. Still can find the Yellowhead and Firefish...The yellowhead was ALWAYS out sifting through sand..

[krackel]

those big boney fins on the firefish serve to lock it into place, did it go in a barnacle or little hole in the LR at night? Weird how they stay put while crabs are munching half of its body away...

[cytranic]

Yup it went in a hole...

[tdwyatt]

Firefishes and the yellow headed gobies are often difficult to get to eat in a new system, in particular if there are other fish nearby. At times, firefish in particular will hide or stay at an "alert" status while feeding is going on in a system. Many issues with yellow heads, much has to do with their shyness and social structure.

Too late for posting tonight, but there should be similar posts in the archives on this issue. When many fish die, they will be quickly consumed by the crabs and other janitors in the tank, so unless you saw the crab actually catch the fish, I would be suspect of most small crabs as the cause of death. More likely in a new system, these fishes simply did not eat, or had issues with acclimatization, or other issues not evident on first look. Fish that don't start eating, especially if they were not eating well in a mixed tank at the LFS, usually will die of starvation at one to two weeks.

Sorry to be so brief, but I gotta gota bed.

[cytranic]

No problem thanks. I dont think they were eating much..It might have something to do with it.

[Geoff]

there is always the chance of a rouge crab if the system is fairly new or new LR has been added.

G~