Ancistrus should be fed mainly on vegetarian foods. Prepared foods include algae wafers and spirulina based sinking food. Vegetables such as courgette/zucchini, and (English) cucumber are an excellent addition to the diet, along with the odd, small amount of more meaty foods.
A good complement to most aquariums, they are not aggressive to other species. Males may fight over territory if kept in too small a tank.
Appropriate with most community fish that aren't overly big or aggressive.