Banded butterflyfish

About

The banded mariposa (Chaetodon striatus) is one of the most recognizable butterflyfish in the Atlantic, wearing a crisp white body crossed by four bold black vertical bars and finished with a black-edged tail. It ranges across a wide sweep of the Western Atlantic, from the cooler waters off Massachusetts all the way down to southern Brazil, including the Gulf of Mexico and the Caribbean, with an isolated population at St. Paul's Rocks in the Eastern Central Atlantic. On the reef, adults are typically seen alone or in bonded pairs, and they form monogamous partnerships during breeding. What makes this species genuinely interesting is its social flexibility: groups of up to around twenty individuals will sometimes gather to feed on plankton in the water column, and these aggregations occasionally function as impromptu cleaning stations where reef fish like grunts, parrotfish, and surgeonfish line up to have parasites removed. In the wild, the diet covers polychaete worms, coral polyps, crustaceans, and mollusk eggs, which is where aquarium keeping gets complicated. Like most butterflies that nibble coral polyps, this one can be a challenge to transition onto prepared foods, and it is best suited to keepers who have some experience coaxing finicky fish to eat. A reef tank is not a good fit here.