Ancorina radix Marenzeller (1889) forms brownish masses with long hollow papillae issuing from it somewhat like roots, hence its name. It is white interiorly. The surface is rough and texture is firm, crumbly. It is a Mediterranean species reported a few times from deeper water along the west coasts of Spain and France.
Colour: Brownish, with white interior.
Shape, size, surface and consistency: Globular or flattened masses, from which several long hollow fistules arise. Their thinly tapering extremities may bud off, to form asexual propagules. Diameter of the basal mass up to 3 cm, papillae up to 2 cm long and 4-5 mm diameter. Surface rough, but not hispid. Ostia in cribriporal areas; oscules at the end of the papillae also forming sieve like areas. Consistency presumably firm, crumbly.
Spicules: Megascleres: Fusiform huge oxeas, straight, in two size categories: 4-5 mm x 55 µm and 750 x 12 µm; triaenes shaped somewhat inbetween ortho-and plagiotriaenes, also in two size categories: 1600-1900 x 80 µm with cladi 220 x 45-50 µm, and small ones of 600-800 µm; anatriaenes also in two size categories 1000 x 17 µm with cladi of 90 µm length, and smaller ones of 600-800 µm. Microscleres: oxyasters in two size categories: with 8-12 conical, rugose rays: 45 µm, and with numerous smooth rays: 12-15 µm; sanidasters with short truncate rays: 12 µm.
Skeleton: A thin cortex of about 1 mm contains chones (sunken cavities) and cribriporal lacunae (roofed-over inhalant cavities). At the surface it has a thick mass of sanidasters; tracts of smaller triaenes and oxeas traverse the upper cortex; lower down the mass of microscleres is carried by the clades of the large triaenes. Oxeas make up most of the interior skeleton, and asters are interspersed in the choanosome.
Ecology: Known from 75 m off Roscoff, and it was dredged in the estuary of the Rance; in the Mediterranean it has a range of 4-126 m.
Distribution: Predominantly Mediterranean; known from Roscoff and the estuary of the Rance (Normandia).
Etymology: radix (Latin) = root, referring to the fistular outgrowths.
Type specimen information: No type material in BMNH.
A rare species known in the area from two records off the W coast of France. It is the only Ancorina species known with certainty from Western Europe. It can be easily recognized microscopically by its possession of sanidasters (rods with conical rays); Stryphnus species have likewise euasters and streptasters, but the latter are amphiasters with comparatively shorter rhabd and longer rays.
Source: Topsent, 1894.