Bluetail trunkfish (Ostracion cyanurus)

   Adult males are typically dark blue with spots on the sides and underparts and greenish-yellow on the upper body, unspotted. Females are yellow with blue spots and red cheeks. Females have a slightly concave dorsal profile of the head, while males have a convex one. They are distinguished by a unique "shell" of fused bony plates, a slow movement, and the ability to secrete the venom ostraciotoxin when stressed.