Smallest flatfish

The smallest species of flatfish (order Pleuronectiformes) is the large-scale righteye flounder (Nematops grandisquama), which as an adult attains a maximum length of 9 cm (3.5 in). It is a demersal species, living in the water column just above the seabed and the benthic zone, in tropical waters off Bali in Indonesia and also off south-west India, in the Indo-West Pacific Ocean. Two closely related species are only marginally longer – N. nanosquama (9.5 cm/3.7 in) and N. microstoma (10 cm/3.9 in).

The name "flounder" is commonly if taxonomically loosely applied to a wide range of quite distantly related flatfish species, collectively spread across five different taxonomic families. The large-scale righteye flounder belongs to the family Pleuronectidae (the righteye flounders – its species possess both eyes on the right side of their face).

The other four families containing species referred to as flounders are Achiropsettidae (the southern flounders), Bothidae (the lefteye flounders), Paralichtyidae (the large-tooth or sand flounders), and Samaridae (the crested flounders).