Bathypera goreaui Millar & Goodbody, 1974

Monniot, Françoise, 2018, Ascidians collected during the Madibenthos expedition in Martinique 3. Stolidobranchia, Pyuridae and Molgulidae, Zootaxa 4459 (3), pp. 401-430 : 401-403

Bathypera goreaui Millar & Goodbody, 1974

Fig. 1

Station: AB 191 (MNHN S2 BAT.B 35; slide S2. 770)

Two specimens 5mm and 3mm large were attached to a piece of dead coral. The body is dome-like ( Fig. 1A ), bright red and covered with spicules. The siphons are well apart, not protruding, opening in a slit; their internal tunic contains smaller sizes of the same spicules as those at the body surface. The body wall is thin colourless in formalin ( Fig. 1B,C ), with a musculature in bundles radiating from the siphons to the body sides and becoming thinner transversally. The oral tentacles are of 2 sizes: 8 poorly branched and smaller simple ones intercalated. The dorsal lamina is made of pointed languets. The branchial sac has 6 high folds on each side ( Fig. 1D ). Spiral stigmata make deep infundibula. The formula of the larger specimen is: ER (11)1(12)1(13)1(13)1(10)1(10) DL (10)1(10)1(12)1(12)1(10)1(7)1 E L.

The digestive loop is long and opened ( Fig.1D ). The stomach has a thin wall with a large lobed diverticulum on each side ( Fig. 1D ). The intestine is isodiametric ending in a smooth anus. The digestive loop is linked to the body wall. There is one elongated gonad on each side ( Fig. 1D ) attached to the body wall; the left gonad is located inside the gut loop. The ovary is tubular sided by 2 series of testis vesicles. The gonoducts are short and linked together at the tip of the gonad. Small endocarps are irregularly placed on each side of the body wall.

The spicules 35µ in diameter have the characteristic shape of the genus with a basal disc below a spherical bulb erect in triangular spines of equal length. The specimens from Martinique correspond in all points to the original description. They constitute the second record of B. goreaui in the Caribbean region from where they probably are native. The genus Bathypera contains only 4 other species all from the Arctic or Antarctic deep seas. All differ in having a stomach with longitudinal folds and without diverticula. B. splendens Michaelsen, 1904 and B. hastaefera Vinogradova, 1962 have 6 branchial folds on each side. B. feminalba Young & Vázquez, 1995 has 7 branchial folds and B. ovoidea Ritter, 1907 has 9 branchial folds on each side.

Figures

FIGURE 1. Bathypera goreaui. A, one specimen, scale bar = 2mm; B,C, dorsal and ventral sides of a specimen without tunic; D, dissection (stained).