Pyura munita ( Van Name 1902 )

Monniot, Françoise, 2018, Ascidians collected during the Madibenthos expedition in Martinique 3. Stolidobranchia, Pyuridae and Molgulidae, Zootaxa 4459 (3), pp. 401-430 : 417-419

Pyura munita ( Van Name 1902)

Figs 16 , 17

Halocynthia riiseana var. munita Van Name, 1902 , Bermuda Pyura munita: Monniot C. 1972 Bermuda; 1983 Martinique. Rocha et al 2012b, Mexican Gulf.? Pyura millari Rodrigues, 1966 Brazil. Stations:AB 149. AR 135, 144, 170, 196. AS 78. (MNHN S2 PYU 503; 505)

The body is entirely incrusted with sand ( Fig. 16A ) with the siphons slightly protruding and distant of 1/3 of the body diameter. Dorsally, between the siphons is a groove of the tunic. The tunic is thin with triangular spinules of 35µ ( Fig. 16D,E ) and luminescent blue-green cells at the siphon edge. The body wall is clear except on the siphons which were red in life. The musculature forms strong sphincters at the siphons and muscular fibres in bundles extend from the siphons to the body sides, but only thick on the dorsal side and becoming thinner and sometimes almost absent over the gonads and gut ( Figs 16B ; 17A ). There is a thin velum at both siphons. The oral tentacles are poorly ramified, 12 are large separated by smaller ones. The prepharyngeal band is double in a wide dorsal V containing a U-shaped dorsal tubercle FG. 17A). The dorsal lamina in languets does not begin immediately below the neural area. The branchial sac ( Figs 16C ; 17B ) has 6 high folds recovering each other. The formula on the right side of a specimen 2.5cm large is: E- 4 (10) 4 (15) 5 (18) 5 (18) 4 (14) 4 (17) 2 -DL.

The longitudinal vessels are spaced on the folds. There are spiral stigmata at the top of the infundibula. Parastigmatic vessels are present. The digestive tract ( Figs 16B ; 17A ) occupies a large part of the left body side and describes a wide loop. The intestine is isodiametric ( Figs 16B ; 17A ) ending in an anus with small denticles. The hepatic gland has two different parts ( Fig. 17A ): a large papillated mass at the pyloric side of the stomach and 2 smaller groups of papillae on each side of the narrow cardia. There are no endocarps on the gut. The gonads ( Figs 16B ; 17A ), one on each side are made of round hermaphrodite well separated lobes alternating on each side of a longitudinal duct ending in a long papilla ( Fig. 17A ). There are no endocarps on the gonads and no endocarps on the body wall.

Described from the Bermuda Islands ( Van Name 1902) and found again in the same region ( Monniot C. 1972), P. munita is recorded now from Martinique with all characters given in the previous descriptions. Pyura millari Rodrigues, 1966 (São Paulo) with same tunic, branchial stigmata and total absence of endocarps is certainly a junior synonym of P. munita .

P. munita differs from other Caribbean Pyura species with 6 branchial folds by its tunic incrusted with sand, the spinule shape and size, the total absence of endocarps and a not inflated isodiametric intestine.

Figures

FIGURE 16. Pyura munita. A, one specimen, scale bar = 5mm; B, C, dissections (stained); D, E, spinules, scale bar D = 35µ.

FIGURE 17. Pyura minuta (stained). A, dissection; B branchial sac, scale bars = 1cm.