Agree with the above. May expand a bit.
I was wondering, what's the average size a Lima Shovelnose usually gets to in an aquarium?
***If you are in the USA, chances are 99.99% your LSN is in fact a Sorubim elongatus with max size of ~1'. True Sorubim lima grow to 2'. Been seen in Europe mostly, 1-2 cases in the US reported here.
Also how long does it take to reach its potential size?
***From 3" to 8" in about 4-6 months, 10x slower from there.
Also would it be safe with an Oscar?
***IDK oscars that well. I imagine when an oscar exceeds 1', I'd be worried a bit perhaps even with a large LSN. Oscar can reach 1.5'.
What are their eating habits?
***When comfortable, they learn quickly to take cut fish and pellets IME.
Do they tend to be shy when eating?
***When comfortable, no. If stressed, yes.
Or are they agressive eaters?
***I'd say they feed very well if the competition isn't too boisterous. They don't need, nor eat as much food being stick-like versus other catfish / fish same length that are more full bodied.
Will I need to spot feed an Elongatus? Or would he be able to compete for food with an Oscar?
***Hard to say but I'd think you shouldn't have a problem, again, if your LSN is comfortable. In general, they are indeed shy and stressable fish. If the oscar bites and chases it, it may just get leftovers from the bottom as oscars are messy. Dim lights, vertical decorations / furniture, areas of calm water, company of kin, no bullying, pristine water, adequate aeration all help keep it comfy. They don't hide or don't hide much when comfortable either. Their preferred mode of hiding and ambush is mimicking a twig floating vertically in the vegetation, along wood, rocks, etc.
