Argentina sphyraena


Otolith description
The general otolith shape is oval and pointed. The sulcus is straight and open and runs along the full length of the otolith. Ostium and cauda are distinguishable. The ostium is shorter but wider than the cauda. The surface of the inside, sulcus and outside is smooth. The dorsal margin has big lobes, while the ventral margin is smooth and rounded. The posterior margin is irregular and indented at the cauda. The rostrum of the otolith is well developed and pointed, while the antirostrum is indistinct. The otolith is thin and flat at the inside and somewhat concave at the outside. Otoliths of argentine do not exceed 8 mm in length.
Argentine otoliths are difficult to distinguish from other salmoniformes, such as greater argentine Argentina silus and smelt Osmerus eperlanus, and atherinidae such as sand-smelt Atherina presbyter. The sulcus of argentine runs over the centre while in greater argentine the sulcus runs dorsally from the centre of the otolith. The rostrum of greater argentine is more rounded compared to argentine otoliths. Otoliths with length >10 mm are always of greater argentine. Otoliths of smelt are much thicker than the delicate otoliths of argentinidae. The sulcus of argentine and greater argentine is less well developed as in sand-smelt otoliths. Otoliths of sand-smelt have a round rostrum compared to argentinidae and the general shape of the otolith is also much rounder in sand-smelt.
When eroded the sulcus and rostrum remain distinct. The margins are smoothed. Otoliths that have gone through a digestive tract of an animal often have the rostrum broken.

Fish length and distribution
Argentine can grow up to 30 cm. Argentine is a demersal roundfish (ARGESPHY.TIF) that is found up to 200 m depth close to muddy bottoms. It spawns from March to July (Wheeler, 1978, Muus et al., 1999).
Argentine is distributed along the shores of the NE Atlantic and Northern North Sea.

Sample origin
Northern North Sea.