What happened to his fin?

[Peach02]

Mandarin fish that I have had for about 3 months has lost part of its left front pectoral fin. his swimming ability does not seem to be impaired at all. Photos below, does anyone know what caused it and how to treat

other fish are
1x coral beauty
1x bicolour blend
2x occelaras clown (small)
2x fire goby
1x mandarin fish (smaller female newly introduced)

Good fin

Bad fin

 

[Flippers4pups]

Bicolor blenny? Blenny or gobies would be my guess. Watch for aggressive behavior out of them towards the dragonet.

 

[cracker]

I'm not sure which fin you speak of.Are there any other suspect fish that could be nipping ? It may have fin rot which they treat with Kanaplex . I'm not a disease,treatment expert by any means .

 

[Peach02]

Bicolor blenny? Blenny or gobies would be my guess. Watch for aggressive behavior out of them towards the dragonet.

Haven’t seen any but will keep a eye open

I'm not sure which fin you speak of.Are there any other suspect fish that could be nipping ? It may have fin rot which they treat with Kanaplex . I'm not a disease,treatment expert by any means .

The fin touching the sand in the second photo, just the blenny and coral beauty that I could think of, is kanaplex harmful to coral