Xanthichthys Triggerfish Xanthichthys spp.

Blue-throated Triggerfish The Blue-throated Triggerfish, also called the Gilded Triggerfish, Xanthichthys auromarginatus, is native to many island coasts and reefs of the Indo-Pacific. Males have blue throats and yellow-bordered fins. Females look similar without the blue throat and yellow-edged fins. Maximum length is 25cm.
Crosshatch Triggerfish The Crosshatch Triggerfish, Xanthichthys mento, sometimes called the Redtail and even the Bluethroat Triggerfish, is native to outer reef slopes of the Pacific. Males have a red-edged tail and yellow-edged dorsal and anal fins. The female has orange-edged dorsal and anal fins and an orange-edged or yellow-edged tail. They grow to just under 30cm.
(Another fish is also called the Bluethroat Triggerfish, Sufflamen albicaudatum, a very different-looking fish of the western Indian Ocean.)