Fish Dying Please Help

[rcracer20071]

Hi,
Within the three weeks I have found my smalled clown fish dead, looked like something had been eating it and now my yellow tailed damsel has diassapeared. The only two things that have been added to my tank is a emerald crab and a Fromia indica starfish, could one of these be to blame?

I have had the same six fish in my tank for nearly 1.5 years now, I thought I had a problem with nitrates previously however this turned out to be my test kit being too old. Heres my setup and current status:


salinity 1.026, Temp 26 (28 on the very hot days), Amonia 0.00, Nitrite 0.00, nitrate 10 - 15 max before water change

No new equipment now for about 4 months.

fish including the dead ones.
- 2 x orange clown fish (small type),
- 1 x royal gramma,
- 1 x firefish,
- 1 x bangi cardinal,
- 1 x yellow tailed damsel

Other
- 6 x blue hermit crabs
- 6 x turbo snails
- 1 x cleaner shrimp
- 1 x sand sifting star fish

New additions
- Soft coral
- 1 x Emerald crab
- 1 x Fromia indica Star fish

 

[Donya]

Definitely not the star. A fish would have to be totally immobilized (dead or so close to death there's no saving it) for such a star to get a hold of it. Emerald crabs are something people like to blame a lot, but they are really not fish catchers except under pretty strange circumstances or with really small fish that could be crippled from a passing nip. However, if a fish is already badly injured from something else, crabs are opportunistic and might deal the last blow. Additionally, a crab that is stressed due to lack of sufficient meaty food might behave rather differently than a well-fed one. Crabs (true crabs and hermits) will also have a snack on already dead things, so that the body was partially eaten doesn't say much unfortunately.

Have you seen an aggression between fish, or any other behavioral changes leading up to this? Does the crab have regular access to meaty food, either as target feeding or leftovers from feeding the fish?