What collective defensive strategy do Wrought Iron Butterflyfish sometimes form while grazing?

Answer

A "wrought-iron ball"

An interesting observation related to the social habits of *Chaetodon daedalma* involves their aggregation behavior during feeding times. They sometimes gather together in large, undulating formations described specifically as a "wrought-iron ball." This grouping is hypothesized to serve as a defensive strategy while multiple individuals graze simultaneously on the reef structures. This behavior highlights a social dynamic in an otherwise solitary foraging activity.

What collective defensive strategy do Wrought Iron Butterflyfish sometimes form while grazing?
dietWrought IronButterflyfish