Pyura discrepans ( Sluiter, 1898 )

Monniot, Françoise, 2018, Ascidians collected during the Madibenthos expedition in Martinique 3. Stolidobranchia, Pyuridae and Molgulidae, Zootaxa 4459 (3), pp. 401-430: 410-413

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Pyura discrepans ( Sluiter, 1898 )


Pyura discrepans ( Sluiter, 1898) 

Figs 10View FIGURE 10, 11View FIGURE 11

Cynthia discrepans Sluiter, 1898  , Jamaïca

Pyura discrepans: Monniot C. 1983  (holotype redescription)

Station: AB 159 (MNHN S2 PYU 500, slide 771)

The single specimen 23mm in diameter has a hard brown tunic with a corrugated surface ( Fig. 10AView FIGURE 10). The siphons are not protruding, spaced at 1/3 of the body length. No siphonal spinules have been seen, either around the siphons openings or on the brown internal lining of the siphons. The body wall was red but turned yellow in formalin ( Fig. 10BView FIGURE 10). The musculature is composed of strong siphon sphincters and regularly crossed fibres on the body. Both siphons have a thin velum. There are 18 oral tentacles with ramifications of a single order: some smaller ones are intercalated. The dorsal tubercle opens anteriorly in a C in a wide V of the prepharyngeal band. The dorsal lamina ( Fig. 10CView FIGURE 10) is a flat band of tissue with the rim erect in well separated languets. The branchial sac ( Fig. 11BView FIGURE 11) has 6 folds on each side with the formula for the right side: E- (15) 5 (17) 6 (22) 6 (22) 7 (20) 4 (22) 3- DL.

The stigmata are very irregular in shape and distribution: they are oval or round holes often in incomplete rows. The transverse vessels are also irregular. This branchial structure seems to be a characteristic of the species as it corresponds to Sluiter’s description and also to Monniot’s (1983) observations.

The digestive tract ( Fig. 11AView FIGURE 11) occupies the posterior half of the left body side, and forms a wide opened loop. The intestine is narrow and isodiametric. The anus has a smooth rim. The stomach is elongated covered by several papillated hepatic lobes ( Fig. 11AView FIGURE 11). There are no endocarps on the gut. There is one gonad on each side made of well separated lobes whose ducts reach a longitudinal gonoduct ending in a long papilla near the atrial opening ( Fig. 11AView FIGURE 11).

Foliated endocarps are numerous on the body wall and are also present on the gonad lobes ( Fig. 11AView FIGURE 11).

Pyura discrepans  is recorded here for only the second time.














Pyura discrepans ( Sluiter, 1898 )

Monniot, Françoise 2018


Pyura discrepans:

Monniot C. 1983


Cynthia discrepans

Sluiter 1898