Schneider, 1862
Description
Larval body is relatively small, up to 0.6 mm, opaque and yellowish-white, no pigmentiferous amoebocytes. The extensive pigmentation and colouration seem characteristic for the species. When fully developed, there are 5 pairs of larval tentacles, sometimes even 6 pairs just before metamorphosis. There is a single sanguinary globule and an unpaired stomach diverticle. The larva is a very active swimmer. Its pelagic life lasts for 17-20 days.
Size
Maximum length ca. 0.6 mm.
Remark
A. pallida is the larva of Phoronis pallida Silén, 1952; the name is kept as a technical name and is used for the larva only.
Distribution in the North Sea
The adult P. pallida occurs in sand or clayed sand and is known from a few locations in the SE North Sea (German Bight and Skagerrak). The larva A. pallida is recorded from the S and SE North Sea, including the Skagerrak and Kattegat (also recorded from the W Channel). The larva occurs from July to December, with a maximum in September.
World distribution
Scarse information indicates a world-wide distribution; recorded from (sub)tropical and temperate waters.