Banded Wedge Shell

Breeding occurs during the summer months. D. vittatus probably has pelagic larvae. When growth is rapid, it lives for two to three years. Otherwise, the life span may be up to seven years.

D. vittatus lives just below the sediment surface and is often dislodged by wave action. lts large, powerful foot enables it to reburrow immediately and so reduce the danger of predation (Fish & Fish, 1989).
This species is a suspension feeder (Wolff, 1973).

Slim, somewhat triangular and elongated shell with the top directed to the back. Up to 40 mm long and 16 mm high. The back is somewhat acuminate and truncate, the front is more rounded. The sculpture consists of fine grooves radiating from the top that are crossed by growth lines. The lower edge is very convex and coarsely serrated at the inside, hence the Dutch name “zaagje” (literally: little saw). Living specimens are coloured yellow or light purple. The inside of the shell is often yellow ochre or purple. They live directly under the sea floor. In case of disturbance they are able to burrow exceptionally fast.

D. vittatus is found exclusively in the southern part of the North Sea, at depths of less than 30 m. It furthermore occurs in low densities in the western part of the Dutch Wadden Sea. Highest densities are found south of the Frisian Front area. The corresponding low biomass in this area indicates that this concerns juvenile specimens. The highest biomasses are found north of Terschelling and west of Texel. Several other studies report the species from the lower shore to a depth of about 20 m, with a more or less regular distribution and only a few specimens per m² (Eisma, 1966; Tebble, 1966; Hayward & Ryland, 1990).

The distribution area of Donax vittatus is limited to the coastal area of the Belgian part of the North Sea. During both periods the species seems to prefer the western coastal zone. The detailed distribution of Donax vittatus reveals itself best in the 1994-2001 period, when numerous samples were collected in the coastal zone. During this period the species was commonly present from De Panne to Wenduine whereas it was almost absent further to the east. In general, the density remained rather low: up to 40 ind./m2 in the 1976-1986 period and up to 300 ind./m2 in the 1994-2001 period.

In the Dutch part of the North Sea D. vittatus prefers clean fine sand (cf. Ziegelmeier, 1957).

Donax vittatus tends to prefer fine-grained sediments (median grain size 50-250 µm). However, the chance of finding this species in these sediments is not higher than 20%. The species is absent in sediments with a median grain size exceeding 400 µm. Donax vittatus is found in sediments with a mud content ranging from 0 to 80% without a clear preference for a certain mud content.

D. vittatus has a solid, wedge-shaped shell, somewhat triangular in outline. lt is rarely larger than 38 mm. A sculpture of fine concentric grooves and numerous fine radiating striations covers the shell. The inner ventral margin is toothed. The growth stages are clear. The shell is coloured white, yellow, brown or purple, or various shades of these. The interior of the shell is white or stained purple, sometimes tinted yellow or orange (Tebble, 1966; Fish & Fish, 1989; Hayward & Ryland, 1990).