Any number of species of seahorses can be suitable for the right aquarium. Left to right: Hippocampus erectus, Hippocampus barbouri, Hippocampus reidi I’m often asked which species of seahorse aquarists should get for their first aquarium. This question may sound simple enough, but different species behave differently and have varying levels of care required. I’ve put together a list of the most commonly available species, their difficulty level and some additional notes. More: How To Pick Your First Seahorse: 12 Common Seahorse Species Explored