Diplosoma versicolor Monniot, 1994

Monniot, Françoise, 2010, Some new data on tropical western Pacific Ascidians, Zootaxa 2561 (1), pp. 1-29 : 12-13

Diplosoma versicolor Monniot, 1994

( Figures 12C , 13 )

Diplosoma versicolor Monniot F. 1994: 9 Fig. 4 ; Monniot F. & Monniot C. 2001:280 Fig.64D,122B.

Diplosoma ferrugeum Kott, 2001: 337 ; 2004: 2524.

Material. Coll. Coral Reef Research Foundation, Malaysia, South China Sea , Layang Layang atoll (Swallow Reef), 07°22.12’N –113+50.22’ E, 6m, 23/IX/2006 , 0 CDN 9558 - X ( MNHN A2 DIP 175 ) .

The brown and white mottled colonies are edged in brown ( Fig. 12C ). Inflated in life, the colonies become thick crusts when fixed. The common cloacal apertures are wide at the junction of large channels surrounding groups of zooids. The thin surface of the tunic contains dense morula cells and brown pigment cells. A black spot is present against the neural ganglion and the body wall of the zooids has brown pigment cells. The thoraces are contracted so the number of stigmata in the branchial sac of adult zooids could not be counted. But in advanced buds 10 stigmata are in the 3 first rows and 9 stigmata in the fourth row. The muscular appendage originates from the long waist at its anterior part ( Fig. 13A ). The abdomen ( Fig. 13B ) is embedded in a solid capsule of tunic containing pigment and morula cells. A large oocyte (not shown) lies against 2 testis vesicles. The larvae, 1mm in length ( Fig. 13C ), are contained in the basal layer of the colony in contact with the common cloacal cavity. Their internal structure is obscured by pigment cells of the epithelium. Three adhesive papillae are bordered with 4 vesicles on each side. Three blastozooids on one side and one on the other side have already developed thoraces and abdomens. The tail is wound in half a turn around the trunk.

Diplosoma ferrugeum Kott, 2001 corresponds in all characters to D. versicolor : colony shape and colour, pigment and morula cells, zooids, structure of the larva with numerous blastozooids; it thus represents a junior synonym of D. versicolor .

The geographic distribution extends from New Caledonia to east and west Australia and now Malaysia.

Figures

FIGURE 4. Trididemnum lanugineum n. sp.: A: abdomen of a zooid, B: thorax, C: larva. Scale bars: 0.5mm.

FIGURE 12. A: Lissoclinum roseum. B: Lissoclinum timorensis.C: Diplosoma versicolor.

FIGURE 13. Dipolsoma versicolor: A: thorax, B: abdomen, C: larva. Scale bars: 0.5mm.