Aging Pimelodus

[Hydexxi]

I have a 4 line pictus cat that was given to me as a full grown cat in 1999. This catfish is still around. Is there a way to prove thier age, possibly by counting rings on a pectoral fin spine?

[Viktor Jarikov]

Welcome to the Planet!

That's a truly remarkable achievement! Wow. Tremendous.

I doubt it. It is very hard in general. From little that I know, it is sometimes possible to determine age of fish that live in temperate waters with markedly different warm /active and cold /passive yearly cycles, like ichthyologists do for New Zealand giant longfin eels by examining and counting tiny ridges on a tiny bone in their skull.

My impression is anything like this is far harder or unreliable for tropical fish. IIRC, the techniques needed in this case are molecular or atomic based.

I may be way off though, so I'd wait for an expert to chime in.

[Bas Pels]

Good point, Victor

Seasonal growth can be made visable - and I think is will not matter whetehr this growth is seasonal due to cold or to dry conditions.

I would expect fish which hardly eat in the dry season to show a seasona groth pattern, including rings in spines or in otoliths (that are thing in the inner ear, fishes have rather large ones). But pimelodus is a predator, which might be able to eat in all seasons. Stupid fry while the water is high, exhausted or dying fishes when the water is low.

Therefore, while I would expect some fishes to show usable bands, Pimelodus might not be one of them

And for fish kept in aquariums - we will not starve our fishes for months, therefore these fish will not show any yearrings

[Viktor Jarikov]

Thanks, Bas. I missed that angle. Good revision IMHO.

[Hydexxi]

Thank you all for the response. I learned more then I thought I would, you guys are some smart folks!