Altum Ventral Fin Growth - Crooked

Hi All

This is my first post on this great Forum.

I was lucky enough to get 6 wild Atabapo Altums back in September, 2017. However, as the fish have grown I've noticed that the ventral fins on a few fish have not been growing straight as I would expect.

Instead they have grown bent and/or crooked.

Does anyone know what may be the cause or why this happening? Is it due to aquarium size or nutrition issues etc? Or is this something that they grow out?

I've attached a photo for reference.

Regarding husbandry: Fish initially quarantined in a 180 litre (47 gallon) aquarium for 2.5 months. Now moved to a larger 300 litre (80 gallon) aquarium until I can move them to a permanent 558 litre (147 gallon) home. Fish have been fed a varied diet of mysis, blood worms and brine shrimp. However, I predominantly feed freeze dried black worms. Water temp is 28 Degrees Celsius and pH is 7 (NB: I gradually increased to this pH level from when I got them).
Would appreciate any feedback.

Thanks in advance.

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Re: Altum Ventral Fin Growth - Crooked

Based on the growth of my wild atapapos over 3 years, they look perfectly normal. INdividuals have different,but not deformed,ventrals and you can use it to identify large very similar individuals. It could be tank size but mine have been in a 70, then 110 then 220 and ,for their size at the time, it always looked pretty spacious.