Stolonica laevis, Monniot, 2002

Monniot, Claude, 2002, Stolidobranch ascidians from the tropical western Indian Ocean, Zoological Journal of the Linnean Society 135 (1), pp. 65-120 : 76-77

STOLONICA LAEVIS SP. NOV. ( Fig. 10 )

Material

Mozambique: Ibo Island, 10–20 m, reef near the pass, two colonies, coll. C. Monniot, 1995.

Description

The colonies are made of joined globular zooids, 1 cm in diameter, linked only by thin stolons. The tunic is thin and wrinkled and carries some sediment and diverse epibionts mostly around the base of the zooids. Both siphons open at a same level and are not protruding.

The body wall is thin, somewhat transparent, revealing the gut and gonads. The thin musculature is evenly distributed. The oral siphon has a velum and at its base a circle of about 30 tentacles plus tiny buttons. The prepharyngeal band is a high blade, curved into a deep, wide dorsal V. The dorsal tubercle is round with an oblique slit. The branchial tissue is thin and flat. The dorsal lamina has a plain edge; its height increases posteriorly and it turns around the oesophagus entrance on the left side. The longitudinal vessels are numerous and regularly spaced. There is an obvious, but rather low fold, on each side of the dorsal lamina, a slightly more marked fold on the left side only in the anterior half of the body, and on the right side two poorly defined folds that disappear in the posterior part of the branchial sac.

At one quarter of the way down the branchial sac we counted:

Figures

Figure 10. Stolonica laevis sp. nov.: A, zooid ventrally opened. B, stomach. C, some polycarps of the right side of the body. Scale bars: A = 2 mm, B = 1 mm, C = 0.5 mm.