The general shape of the otolith is ovally rounded. The sulcus runs over 2/3 of the total length of the otolith. The sulcus is open at the ostium. The ostium is clearly visible, but the cauda is indistinct. The ostium is deeper and wider than the cauda. When visible the cauda runs slightly dorsally from the ostium. The surface of the inside and outside and the margins are smooth. The margins are rounded. The rostrum is visible and pointed. The antirostrum is indistinct. The inside is convex, the outside is slightly concave. The otolith is thick. Otoliths do not exceed 4 mm in length.
Otoliths of ammodytidae, sandeel Ammodytes tobianus, Raitt’s sandeel and greater sandeel Hyperoplus lanceolatus, are very difficult to identify to species level. The posterior end of sandeel otoliths tends to be slightly more pointed than in other species. The rostrum of Raitt’s sandeel tends to be more pointed compared to other ammodytidae. The sulcus of greater sandeel tends to be slightly wider and the posterior end tends to be slightly lobate. The above features are all variable and the variation between the species is a large as within the species. Size can help to separate the larger greater sandeel; otoliths > 4 mm are always of greater sandeel. Otoliths of both sandeel and Raitt’s sandeel can reach 4 mm in length.
When eroded the sulcus becomes indistinct. Because of the thickness of the otolith, the general shape remains ovally rounded.
Fish length and distribution
Raitt’s sandeel can grow up to 25 cm. Raitt’s sandeel is a demersal schooling fish (AMMOMARI.TIF) found in offshore waters, but can occasionally be found in inshore waters. It is often buried in sand or gravel, but can also be found in schools at the surface. Spawning takes place in winter (Wheeler, 1978, Nijssen and De Groot, 1987, Muus et al., 1999).
Raitt’s sandeel is a very common fish found in the NE Atlantic, North Sea and Baltic.
Southern North Sea.