Brill
Otolith description
Otolith shape is square with a rounded dorsal margin. The sulcus runs over more than half the length of the otolith. The sulcus is open at the ostium and narrow. Ostium and cauda are distinguishable and separated in a straight sulcus. Ostium is longer but cauda is deeper. The surface of the inside is smooth and irregular on the margins. The margins are lobate especially ventrally. In some specimens a small indention at the posterior end is visible. The outside of the otolith is smooth. The rostrum of the otolith is rounded and a small rounded antirostrum is visible in fresh otoliths. The inside of the otolith is convex, whereas the outside is concave. The otolith is thin.
Brill otoliths are difficult to distinguish from other bothidae such as turbot Scophthalmus maximus and megrim Lepidorhombus whiffiagonis. Otoliths of turbot are not lobate but jagged at the ventral margin, but when otoliths are eroded the margins are smoothed in both species. The sulcus of turbot is longer and ostium is deeper than cauda whereas in brill the cauda is deeper. Otoliths of megrim are generally rounder and thicker than brill otoliths. The sulcus of megrim otoliths is not as deep as in brill otoliths, but when eroded the sulcus becomes less distinct in both species. Otoliths with lengths >5 mm are always from brill or turbot and never of megrim.
Eroded otoliths have smooth margins. The sulcus and antirostrum become less distinct with progressed erosion.
The otoliths of 0-group turbot, brill and megrim are not distinguishable. Otoliths of 0-group brill are more squared and indented at the ostium. The surface and margins are smooth.
Fish length and distribution
Brill can grow up to 75 cm. Brill is a bottom-living flatfish (SCOPRHOM.TIF) most commonly found on sandy bottoms but also on mud and gravel. Adult fish live in deeper waters while juveniles are found in the tidal zone (Wheeler, 1978, Witte et al., 1991, Knijn et al., 1993). It spawns from March to August (Muus et al., 1999).
Brill is found in the Eastern Atlantic, Southern North Sea and Baltic, but it is not very common.
Sample origin
Juveniles: Fyke.
Adults: Southern North Sea.