A Black Reef Leatherjacket, Eubalichthys bucephalus, at Jervis Bay.
Flicking the dorsal fin spine back and forwards is usually a sign of aggression. Most likely the two fish in the movie are both males. Thank you to Dr Barry Hutchins for his comments on this behaviour.
Last Updated: 25 September 2009
Tags fishes, ichthyology, Black Reef Leatherjacket, Eubalichthys bucephalus,
