Fin Biting Polypterus

IgnatzMcJockel

Piranha
MFK Member
Jun 28, 2019
309
373
77
Germany
Hey guys, i need your advice.

At the moment i keep in my main Tank 4 Polys.

NameGenderAgeSizeSpecies
AMale~ 3 Years~ 11"Polypterus Delhezi
BFemale~ 3 Years~ 11,5"Polypterus Delhezi
MartyMale~ 2,5 Years~ 12"Polypterus Delhezi
WürmchenMale~ 1,5 Year~ 12,5"PolypterusPolli

My main tank is a well structured 100 gallon with a lot of hiding spots (the pic is a little bit older, but the furnishing is still the same).

IgnatzMcJockel_TOTM_September_19.jpg

I didn't change anything at the tank / food / water in the last few months.

Until the last 5 - 7 days all my polys got along well. They were the most of the time at the same spot or swimming around together or in pairs.

One Year ago i got a small Polypterus Polli. He looked very small, next to my other Bichirs, so i named him "Würmchen" (german for "mite", according to google translate^^).
He grew like hell and reached 12" in i little bit more than half a year and still seems to be growing...
He soon got my favorite fish, because he is very curious and active.

IMG_20201213_115757.jpgIMG_20201224_160023.jpg

Sadly i noticed a few days ago, that he started a little bit of territory fighting with marty. This took about an day. I thought, this could be a one-time occurrence and didn't worry further.
I was away over the weekend. When i got back today, things seems to escalate. Würmchen was following Marty and A (the other Males) and biting their tail and anal fins.
This happened over and over again throughout the day.

Now i am concerned about Würmchens aggressive behavior change and worried about the health of my other Polys.

Could this be a adolescent-spring-mood?
Or could this get a permanent problem?
What is the best way to handle this behaviour?

If you need further information, please ask :)

Thanks in advance!
 

IgnatzMcJockel

Piranha
MFK Member
Jun 28, 2019
309
373
77
Germany
Just make sure the damage stays at just fin nipping, is it just polys in the tank?
At the moment there is only very minor damage at the fins.
There are also 3 EBAs, a pair of Angle Fisch, 3 Bushymouth Catfish and a L114 in the tank.
If i don't mess somthing up, Würmchen was the last fisch i added to this tank...or the L114...they were very close...
 
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IgnatzMcJockel

Piranha
MFK Member
Jun 28, 2019
309
373
77
Germany
Is there a reason why Würmchen is only attacking the males?
Could it cause the aggressoin, that there is only one female and three males in the tank?
 
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