Monandrocarpa monotestis ( Tokioka 1953 )

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 : 20

Monandrocarpa monotestis ( Tokioka 1953) NEW RECORD

Figure 8 A–D

Colonies globular in the present collection, zooids all on the surface; most of the interior is empty colorless transparent tunic. Four branchial folds per side. Zooids with a few endocarps, small and globular, scattered on body wall; none in gut loop. Stomach elongated, ridged, with large curved caecum at posterior end; anus plain but bilobed. Gonads elongate, single testis almost as long as entire gonad.

#1169, tunic about 4mm thick, tough. Elongate colony 4.5 cm long x 3.3 cm wide, plus smaller attached colony. Zooids about 4 mm in length. Nine gonads on left side, seven on right. Branchial formula: Left DL0(6)0(2)1(6)0(2)1E right DL0(8)0(2)0(7)0(3)0E

#4647, examined by F. Monniot. Single colony, attached by the narrow end only, about 3.5 cm long x 3 cm wide at widest part ( Fig. 8 A–D). Zooids about 5 mm long, measured across both siphons. Numerous long slender oral tentacles,>60. Dorsal tubercle a small button, ganglion immediately behind it; dorsal lamina plain. Zooids with up to nine elongate gonads on each side in a single row ventrally, close to the endostyle. Second branchial fold from DL the lowest. Branchial formula:

E1(3)3(7)2(3)2(10)0DL

E0(3)1(8)1(3)1(10)0DL for another zooid

Distribution: Japan, China, Korea.

Detailed references: Tokioka (1953, 1967 as Polyandrocarpa (Eusynstyela) monotestis ), Monniot F. (2009a), Seo & Rho (2014 as E. monotestis ).

Figures

FIGURE 8. A–D: Monandrocarpa monotestis. A: whole colony 3.5 cm in length; B: enlargement of four zooids; C: gut, intestine and a few left side gonads; D: curved caecum at posterior end of gut. E, F: Polyandrocarpa rollandi. E: part of colony, scale bar 8 mm; F: oral siphon showing reddish striping.