Helfrichi Firefish Unknown Attacker

[AMP Tank]

Over the last few weeks someone in our tank has been damaging the fins of our Helfrichi Firefish. We have never witnessed any aggression directly toward the firefish; at first we thought the attacks were occurring at night but it definitely happened in the day this last time.

Here are the suspects (i.e., other tank occupants) in order of likelihood:

Main suspects:
1. 5x Blue Reef Chromis - the three less dominant chromis school around the firefish and I wonder if this is making the firefish a target from the two more dominant chromis.
2. Randall's Pistol shrimp - we are wondering if the pistol shrimp occasionally climbs into the firefish's hidey hole
3. Midas Blenny - The next most 'aggressive' fish in the tank, however, we have never really seem him do anything more than chase the wrasse and hawkfish so seems unlikely, the blenny and fish have neighboring hidey holes.

Unlikely:
4. Aptasia eating filefish - very unlikely has never displayed aggression to anyone, but is very curious and will nip things
5. Carpenter's flasher wrasse - very unlikely has never displayed aggression to anyone
6. 2x Fire Shrimp - very unlikely but I think they would love the opportunity to clean the firefish
7. Flame Hawkfish - very unlikely has never displayed aggression to anyone
8. 2x Clownfish - very unlikey the clowns live on the other side of the tank and rarely leave there corner
9. Black cap basslet - not a suspect (too new to the tank) and lives on the other side of the tank and rarely leaves its cave
10. Pink dot gobie - not a suspect (too new to the tank)
11. 3x very small red legged hermit crabs - there is no way these guys could sneak up on the firefish and inflict this level of damage

Any ideas on behaviors we should be looking for to catch the culprit? Anyone we are ruling out that deserves a closer look?

We are planning on catching the two aggressive chromis and putting them in QT for a few weeks to see if there are any attacks while they are out of the tank. Any other advice on how to handle this? The good news is the firefish does appear to heal pretty quickly from these attacks but we would obviously love to stop them from occuring.

 

[GSnake]

my firefish has lost its filament and regrew another one before. it could be water quality issue, or territory over a specific sleeping space thats causing stress.

 

[A sea K]

My money is on the Midas Blenny. They are known to pick on smaller planktivores ie, firefish

 

[Tchung23]

I think my coral banded shrimp for mine!

 

[shakacuz]

My money is on the Midas Blenny. They are known to pick on smaller planktivores ie, firefish

+1 to this. i have occasionally seen my midas blenny go after my court jester goby. stopped once i added my yellow coris wrasse.

 

[laurenevf]

i lost my firefish to my clownfish so i would keep an eye on them just in case

 

[dhanking]

Midas blenny is pretty aggresive fish. Tries to nip at my radial filefish all the time

 

[steven m]

My Midas Blenny would hunt for my fire fish, to the point they just won’t come out and eventually I never saw them again. And the fire fish were in the tank for 6 months before the blenny.