Sidneioides japonense Redikorzev, 1913

Monniot, Françoise, 2009, Some ascidians from Indonesian marine lakes (Raja Ampat Islands, West Papua), Zootaxa 2106, pp. 13-40 : 22-24

Sidneioides japonense Redikorzev, 1913

(Figure 9)

Material. Indonesia. West Papua, Gam Island, tunnel to Danau Hidden Gam marine lake, 00°26.414’S – 130°41.193’E, 0.5m, 05/XII/2007, coll. L.J. Bell and L.E. Martin, TAG 0 0 5 ( MNHN SID A 5).

The colonies form tan round cushions (Fig. 9A) from 15 to 23mm in diameter, firm but not tough. There is some sand in the tunic surface but not internally. Small colonies have a single common cloacal aperture, the largest have 2 or 3. The zooids are as described in Monniot F. & C. (2006). The atrial languet is remarkably long. The transverse vessels in high membranes lack papillae. There are 10 to 12 rows of stigmata (Fig. 9B) and 25 stigmata in the first half row. Abdomen and larvae are as described in 2006. Sidneioides japonense has a wide Indo-Pacific distribution.

Sidneioides japonense : A, colonies; B, branchial sac stained with hemalum. Scale bar = 1mm.