The distribution of the recessus orbitalis across flatfishes (order: Pleuronectiformes).

The recessus orbitalis is an accessory organ of flatfishes functioning in the protrusion of the eyes. This character, along with cranial asymmetry and a forward insertion of the dorsal fin, have been considered synapomorphies for the Pleuronectiformes. New dissections and examination of images taken in the wild show that the recessus orbitalis is present in all representatives of Pleuronectoidei examined but is absent in the single species of Psettoidei dissected.

A new species of sinistral flatfish of the genus Chascanopsetta (Teleostei: Bothidae) from off Papua New Guinea, western Pacific Ocean.

Left-eyed flounders of the genus Chascanopsetta Alcock 1894 (Bothidae) occur in the Indian, Pacific, and Atlantic oceans at depths ranging from 120 to 1500 meters. They possess some unique features in bothid fishes including a strongly compressed and elongated body and a tremendously large mouth. Currently, nine species of Chascanopsetta are recognized, and three of them (C.