Amphicarpa duploplicata ( Sluiter, 1913 )

Lambert, Gretchen, Lee, Serina Siew-Chen & Teo, Serena Lay-Ming, 2021, Ascidians collected during the 2013 Singapore Strait International Marine Biodiversity Workshop, Zootaxa 4933 (1), pp. 1-38 : 19

Amphicarpa duploplicata ( Sluiter, 1913) NEW RECORD

Figure 7 A–D

#1158, only one sample collected, possibly not fully mature. Zooids attached at bases by common tunic and short stolons. Young buds present. Largest zooid is 11mm in height x 9 mm wide. Examined by Françoise Monniot. Tunic thick, in several layers. Partially dissected zooid in tunic revealed posterior extension of the body wall. Zooids removed from the tunic reveal four thin white lines or stripes in each siphon. Dorsal lamina very flat. Two branchial folds on the left side and two large ones on the right with a slight narrow folding of a third one on the right side only, next to the endostyle ( Fig. 7C ), visible in the stained pinned-out branchial sac removed from the animal. Branchial formula: E1(2?)3(7)5(8)3DL2(9)4(6)5E

Parastigmatic vessels present ( Fig. 7D ). Stomach with many narrow folds as illustrated in Monniot C. (1988, 1991b) and Monniot F. (2010). Many tiny atrial tentacles around the base of the atrial siphon. Endocarps few, separated, large, arranged more or less in three rows. One or more endocarps in gut loop curve. No visible gonads.

Distribution: New Caledonia, Vietnam, Malaysia, Indonesia.

Additional reference: Kott (1985; is A. styeliformis according to Monniot F. 2010).

Figures

FIGURE 7. A–D: Amphicarpa duploplicata. A: dissected individual 11 mm in height; B: undissected body inside opened tunic revealing short stolon at posterior end of body; C: opened branchial sac stained with haemalum showing two longitudinal folds per side, with a very short partial fold on ventral right side (on the left in photo), e=endostyle; D: enlarged view of portion of branchial sac showing parastigmatic vessels. E, F: Eusynstyela hartmeyeri. E: whole colony 6 cm in width; F: enlarged view of four zooids each 6–7 mm in width.