Gattyana cirrhosa (Pallas 1766)

Gattyana cirrhosa is a scale worm known from widespread locations in the North Atlantic, Arctic, and northwestern Pacific oceans, from the intertidal zone to depths of at least 1,200 m (3,900 ft).

Breeding probably takes place in spring (March-June) and the larvae develop in the water column. The species spawns several times during its life. It can reach an age of at least 4-5 years. In the subtidal parts of the area, G. cirrhosa is almost exclusively found in the tubes of the polychaete Chaetopterus variopedatus. Other studies have recorded the species from (empty) tubes of other polychaetes such as Lagis koreni and Amphitrite johnstoni, and in Arenicola burrows. G. cirrosa, like all polynoids, is considered a predatory carnivore. Small crustaceans, echinoderms, polychaetes, gastropods, sponges and hydroids have been mentioned as prey items. (Hartmann-Schröder, 1971; Wolff, 1973; Curtis, 1977; Fauchald & Jumars, 1979; Hayward & Ryland, 1990).

This species is very abundant at the Oyster Ground, where it forms a substantial part of the infaunal biomass. G. cirrhosa also occurs in the Delta area (Grevelingenmeer, Ooster- and Westerschelde). The species is (almost) absent from the Southern Bight and the Wadden Sea.

G. cirrhosa shows a preference for the muddier types of sediment as found in the Oyster Ground.

This species has a flattened body that is oval in outline. lt is composed of up to 38 segrnents and reaches 40 mm in length. The dorsal surface is covered with fifteen pairs of soft scales (elytra). These elytra are covered with minute spines and have a fringe of papillae along the outer edge. The head bears four eyes, one median and two lateral antennae. The elytra have a distinct dark spot in the centre (Hartmann-Schröder, 1971; Hayward & Ryland, 1990).