Fin Biting?!

[WarrendaFish]

My Senegal keeps nipping at my Del's fins....??? They've been together for more than a year, maybe two. I will separate for now, but just wanted an explanation. They are both about 7" long in a 125g. heavily planted, lots of drift wood, good water param's. I've never seen it before. There are other tank mates but they do not seem to be involved. I watched it happen. Any Ideas?
Thanks in advance....

 

[repella42]

Wow! My senegal seems to dumb or tunnel visioned to even notice other fish till they are right in front of him lol. Unless they fit in his mouth.

 

[GarNiac]

add more bigger bichirs in the tank.

 

[Cholly]

Look at their anal fins. Are they male and female? Or is it an actual aggression issue? Usually if it's an aggression issue it's the other way around, del munching on sen.

 

[WarrendaFish]

The Sen I'm pretty sure is a male, with a fatter anal fin. I'm not sure about the del. It's been hiding out. I separated the 2. But the sen has bitten pectoral fins anal fins, most fins. They have been best buds up to this point. Could it be a mating thing? My dempseys fight after they lay eggs but that's after they spawn. I would greatly appreciate any help here. Thanks

 

[WarrendaFish]

So no feedback huh????? Well separated my del is healing and things are fine. still no idea why it happened though

 

[mike_sema]

my endli was doing this to my lap and congi but after rearranging the tank a Little he stop

 

[Cohazard]

Sounds like territorial/dominance establishing aggression.

The spawning behavior in polypterids can in volve some biting, but it's usually much more peaceful, the male will swim up to the female and nudge her.