Grey gurnard
Otolith description
The general otolith shape is triangular. The sulcus runs diagonally from the anterior up to the posterior over the length of the otolith. The sulcus is open at the ostium. Ostium and cauda are distinguishable and separated by a narrowing of the sulcus. The cauda is wider than the ostium. The surface of the inside and outside smooth. The ventral margin is slightly rounded and lobate. The dorsal margin is rounded and smooth. The rostrum is pointed as is the antirostrum which is smaller than the rostrum. The anterior margin is indented at the ostium. The posterior margin is pointed and there is often a small indentation visible. The inside is convex and the outside concave. The otolith is thin.
Otoliths of grey gurnard are difficult to distinguish from other triglidae, such as tub gurnard Trigla lucerna. The otoliths of grey gurnard, though triangular in shape, are generally rounder compared to tub gurnard. In tub gurnard otoliths the rostrum and antirostrum tend to be of the same size, while in grey gurnard the antirostrum is smaller. However, in small tub gurnard the antirostrum is also smaller than the rostrum. The sulcus of grey gurnard otoliths is deeper than in tub gurnard. Otoliths >6 mm are always of tub gurnard.
When eroded the sulcus remains visible and the otolith is rounder.
Otoliths of juvenile tub gurnard already have the shape and look of bigger otoliths, except for the smoother and rounder margins, rostrum and antirostrum.
Fish length and distribution
Grey gurnard can grow up to 45 cm. Grey gurnard is a bottom-living fish (EUTRGURN.TIF) found in offshore waters mostly on sandy grounds, but can also be found on other bottoms. It forms small schools at the bottom but is found solitary higher in the water column at night. It spawns from April to August in moderately deeper water (Wheeler, 1978, Nijssen and De Groot, 1987, Knijn et al., 1993, Muus et al., 1999).
Grey gurnard is the commonest of the triglidae and found along the coast of the Eastern Atlantic and North Sea.
Sample origin
Southern North Sea.