PlanetCatfish.com

I have a 38 gallon planted aquarium with a keyhole cichlid, a curviceps, 2 platies, 2 skunk cories, an otocinclus, 3 siamese algae eaters and some amano shrimp. I would like to add a Pimelodus pictus, do you think it would work out?

I would not recommend it. You have a tank of peaceful fishes that will find the hyperactivity of a pictus disturbing. A pictus would also out compete most of the other fishes you have for food.
-Shane

is there any kind of catfish other than cories and algae eaters that I could add? maybe a raphael cat?

Raphael cats would be one choice.

There are others too - woodcats (auchtenperiidae), perhaps?

--
Mats

Pictus would be best kept in a group & as stated previously not really a good idea for the set-up you have - what about Dianema? peaceful, fairly active - a bit like a bigger cory.

if you were to look wider than south america you could perhaps considr synodontis flavitaeniatus - obviously things depend upon availability & budget.

I wouldn't recommend any woodcat for your setting. Not because they should be kept in groups like P. pictus, but they might disturb your fish by their nocturnal behaviour and their voracious feeding habits.

The suggestion is worth thinking over, especially because it behaves like a bigger Cory (see above), but looks rather different (click link).

Another reason is that the pictus will almost certainly eat your shrimp, and maybe the oto too.