We might think of some reef fish as being rare but this video of a huge school of wrought iron butterflyfish shows how locally common some fish species can be. While most aquarist would be content to see even one Chaetodon daedalma here in the U.S., these lucky divers at have born witness to a what they call a “wrought iron ball” with hundreds of medium sized fish swimming together and converging and dispersing from grazing spots within seconds. The video was uploaded by a dive shop called Bientos that operates out of Hachijo-jima, a popular dive spot in the Izu Islands South of Japan but north of the Ogasawara Islands. We’ve posted our share of wrought iron butterflyfish videos in the past but this writhing mass of this species really takes the cake.
Jake Adams has been an avid marine aquarist since the mid 90s and has worked in the retail side of the marine aquarium trade for more than ten years. He has a bachelor’s degree in Marine Science and has been the managing editor of ReefBuilders.com since 2008. Jake is interested in every facet of the marine aquarium hobby from the concepts to the technology, rare fish to exotic corals, and his interests are well documented through a very prolific career of speaking to reef clubs and marine aquarium events, and writing articles for aquarium publications across the globe. His primary interest is in corals which Jake pursues in the aquarium hobby as well as diving the coral reefs of the world.