The Four Spot Butterfly, Chaetodon quadrimaculatus, is a distinctly colored and patterned butterfly with a yellow underbelly, black dorsal fin, with two white spots on either side. The Four Spot Butterfly can sometimes be difficult to keep in an aquarium setting for a beginner aquarist. They require at least 50 gallons, can nibble on certain coral species, and can become territorial with smaller fish and other butterfly species. Further, the Four Spot Butterfly will pick on sessile invertebrates and even small hermits and crabs if not fed well. Most Four Spot Butterflies will take meaty frozen foods like mysis or brine shrimp combined with algae and other meaty foods. Some Butterfly species, though not the Four Spot, will only eat fleshy coral polyps. Overall, the Four Spot Butterfly is an interesting addition to any tank but must be introduced with preparation and understanding - if that is done then the Four Spot Butterfly will surely thrive.