Herdmania polyducta (Monniot C. & Monniot F., 1989)

Monniot, Françoise & Monniot, Claude, 2001, Ascidians from the tropical western Pacific, Zoosystema 23 (2), pp. 201-383 : 343

Herdmania polyducta (Monniot C. & Monniot F., 1989)

( Figs 105 ; 130A )

Pyura polyducta Monniot C. & Monniot F., 1989: 237 , fig. 4, pl. 1F, G. Type locality: Philippines.

MATERIAL EXAMINED. — Philippines. W Luzon, Zambales, Masinloc town, Luan Island, 15°29.90’N, 119°54.44’E, 7 m, 4. V.1995 ( MNHN S2 HER 15).

DESCRIPTION

The body is round, covered with rhizoids ( Fig. 130A ), and only the siphons are clean, with red pigment spots. The body wall is thin and translucent and contains acicular spicules. The tentacles are white in life, of at least five orders of size. The largest are in two or three orders, and numerous smaller one are intercalated. The largest tentacles are doubly ramified.

The prepharyngeal band has unequal rims, the anterior blade higher. The dorsal V is pronounced. The dorsal tubercle is protruding; its opening is horseshoe-shaped with horns inwardly rolled ( Fig. 105B ). The short dorsal lamina is made of long, sharp languets; it stops ahead to the oesophagus entrance.

The branchial sac has eight folds on each side. The formula on the right side is:

R.E. 3 9 3 13 3 17 3 17 3 17 3 15 3 15 3 13 3 D.L. On the left side the eighth fold, near the endostyle, is not complete and the seventh fold is low. The folds are high and overlap each other. A crest circles the oesophagus entrance where the folds end.

The gut forms an open loop ( Fig. 105A ). The hepatic gland has three unequal lobes ( Fig. 105A ). The anus has digitiform lobes.

There is one elongated gonad on each side ( Fig. 105A ). The left gonad is entirely included in the intestinal loop. The testis completely covers the ovary and opens in multiple short papillae ( Fig. 105C ). The long oviduct ends in a wide papilla without encircling membrane ( Fig. 105C ).

REMARKS

This species is now placed in the genus Herdmania by virtue of its soft consistency, the presence of acicular spicules, its large number of branchial folds, and the elongated shape of its gonads. The characteristics of the genus Herdmania have been detailed by C. Monniot (1992).

Figures

FIG. 105. — Herdmania polyducta (Monniot C. & Monniot F., 1989); A, specimen ventrally opened; B, dorsal tubercle; C, gonoducts. Scale bars: A, 1 cm; B, C, 1 mm.

FIG. 130. — A, Herdmania polyducta (Monniot C. & Monniot F., 1989); B, Pyura gangelion (Savigny, 1816); C, Pyura styeliformis n. sp.; D, Microcosmus bitunicatus n. sp.