The Spotfin Butterfly gets its name for the small, black spot located on the end of the dorsal fin. But what is really neat about the Spotfin Butterfly is at night, this fish undergoes remarkable changes. The large, dark mark on the dorsal fin becomes black and broad, and dark bands appear on the body. It has also been known to swim upside down, and occasionally squirt water above the waterline. The Spotfin Butterfly is peaceful, most commonly found in shallow waters around coral reefs alone or in bonded pairs, who form a lifelong partnership. Most active during the day, they change color and seek shelter for sleep in the evening, as they are highly vulnerable to larger predators. The tank you put your butterfly in should be full of peaceful tank mates. Known for being hardheaded,the Spotfin Butterfly can be somewhat difficult to entice at first. To encourage eating, offer live, brine shrimp, clam, and squid or shrimp. Once eating regularly, you can begin feeding frozen brine shrimp.