Long rough dab
Otolith description
Otolith shape is oval. The sulcus runs over more than half the length of the otolith. The sulcus is closed, narrow and very deep. Ostium and cauda are well distinguishable and deep. The ostium is deeper and longer than the cauda. The sulcus is straight but ostium and cauda are well separated. The surface of the inside and outside of the otolith is smooth. In some specimens the otolith is thicker along the edges of the sulcus. The margins are rounded with a pointed end at the dorsal posterior side. The rostrum of the otolith is rounded. The inside of the otolith is slightly convex. The outside of the otolith is convex. Otoliths of long rough dab are very similar to dab otoliths but can be distinguished because the length-width ratio is smaller in long rough dab otoliths. Also the otoliths are thicker and convex whereas dab otoliths are flat.
When eroded the otoliths are rounder and the sulcus becomes less distinct. The thickness of the otolith does not change noticeably.
Otoliths of 0-group fish are not distinguishable from other flatfish with great certainty. The otolith is round to oval and the sulcus is hardly visible.
Fish length and distribution
Long rough dab can grow up to 50 cm. Long rough dab is a bottom-living flatfish (HIPPPLAT.TIF) that lives in deeper waters on fine sandy or muddy bottoms (Wheeler, 1978, Nijssen and De Groot, 1987, Witte et al., 1991, Knijn et al., 1993). It spawns in spring and lives in midwater when spawning.
Long rough dab can be found on both sides of the Atlantic and in the North Sea.
Sample origin
North Sea.