Q. I have a 33-gallon aquarium with three angelfish, and I’d like to add rams as well as some other kinds of fish. Would the rams be a good idea, and if so, how many should I add? Also, any suggestions for what other species I could add?
Darren Phifer
Maplewood, Oregon

A. As far as a 33-gallon aquarium goes, three angelfish (Pterophyllum) are all the angelfish I’d house, but it does leave a little room for some rams and perhaps some other additions, as well. Because angelfish tend to occupy the mid level of an aquarium, meaning they don’t spend a lot of their time nosing around the bottom or surface areas, it leaves the lower and upper areas of the aquarium for other species.

Click image to enlarge Ram cichlid by Tony Terceira.

The rams (Mikrogeophagus) you ask about would tend to use the bottom areas of your aquarium and as a result will likely not present too much of a challenge to your already established angelfish. Either of the two ram species would be fine – but keep in mind that Bolivian rams (M. altispinosus) do get somewhat larger and tend to be a little more hardy than their Venezuelan/Colombian counterparts (M. ramirezi). I’d suggest only a pair of rams – with any more than that, you’ll have constant aggression over territory.

As for adding other species, consider finding fish that use the upper area of the aquarium. The most popular choices for surface-dwelling fish species are the hatchetfishes, family Gasteropelecidae. Unfortunately, there aren’t really a lot of other choices because if you think about it, being a little fish in the Amazon, living at the surface can be dangerous – with big fish looking up and fish-eating birds looking down. Hatchetfish are able to make a living at the surface partly because they have evolved an effective escape response – jumping into the air. I have to say at this point that despite a widely held belief that hatchetfishes fly, they do not. They simply propel themselves into the air and become passengers of a trip governed by initial trajectory and prevailing wind conditions. It’s a great way to simply disappear right in front of your attacker. Because angelfishes are more predatory than most want to believe, I’d suggest some of the larger, more robust species, such as the silver hatchetfish (Gasteropelecus sternicla) or the platinum hatchetfish (Thoracocharax stellatus).