Southernmost observation of a juvenile bumphead parrotfish, Bolbometopon muricatum (Valenciennes, 1840)

Abstract. The bumphead parrotfish, Bolbometopon muricatum, is an iconic and ecologically significant species that is vulnerable to extinction. Although the Great Barrier Reef provides extensive habitat for this species, the scarcity of juvenile fish in this region may suggest that these populations rely on colonisation by adults from further north, rather than local larval recruitment. Consequently, B. muricatum populations exhibit the strongest latitudinal gradient of any parrotfish on the Great Barrier Reef. Here, we review all records of B. muricatum from the southern Great Barrier Reef and report a new observation of a juvenile at Heron Reef. This is the southernmost report of a juvenile for this species. Given its size (standard length, 25–30 cm), this individual is likely to have settled as a larval recruit in the relative vicinity of Heron Reef, rather than migrating from a more northern site on the Great Barrier Reef or beyond.