Family Pleuronectidae

Righteye flounders

Flatfishes represent a distinctive group of primarily marine fishes that are readily distinguishable by their bilateral asymmetry, with both eyes on the same body side. They have been observed to have remained largely unchanged since the Eocene epoch (34–56 million years ago). The family Pleuronectidae is recognised to comprise 40 genera, and approximately 103 species distributed across all marine habitats worldwide. It should be noted that several other species (e.g., Citharus [family Citharidae], Solea [family Soleidae], Scophthalmus [family Scophthalmidae]) may occasionally be found in estuaries.

Further reading. Whitehead et al. 1986 (identification of marine species); Cooper & Chapleau 1998 (phylogeny); Evseenko 2004 (checklist).