Synoicum

Fortaleza, Maria Tarciana Vieira & Lotufo, Tito Monteiro Da Cruz, 2018, Polyclinidae (Ascidiacea: Aplousobranchia) from the Gulf of Mexico, collected during the “ Hourglass ” cruises (1965 - 1967), Zootaxa 4422 (4), pp. 519-536 : 532-533

? Synoicum pulmonaria (Ellis & Solander, 1786)

( Figures 16, 17 )

Alcyonium pulmonaria Ellis & Solander, 1786: 175 apud Berrill (1950).

Synoicum pulmonaria Van Name, 1945: 56 (e sinonímia). Berrill, 1950: 91.

Examined material: collected in 19/5/1966, 27°37’N, 083°28’W, 36.6 m, specimen # EJ-66-203.

Description: Colony formed by numerous stalked heads up to 1.2 cm long and 0.4–0.8 cm thick, with more than one cloacal opening in each. Tunic firm with sediment trapped in the lobes. Attached by a broad base with some foreign material included.

Zooids long and slender, measuring 5.64 mm in length on average (length range: thorax plus abdomen = 2.56– 3.10 mm; post-abdomen = 1.09–5.44 mm). Branchial siphon measuring between 0.11–0.22 mm with six round lobes. Atrial opening relatively broad and smooth, located between the second and fourth row of stigmata. Atrial languet with three small teeth between 0.19–0.96 mm in length. Around 20 longitudinal muscle fibers running in parallel on each side of the body, sparsely distributed and reaching the post-abdomen. Pharynx with 15–19 stigmata rows. It was not possible to observe the number of stigmata per row. Esophagus long. Stomach small and slightly areolated with anterior and posterior ends slightly flattened. The size of the stomach and esophagus together are equal to slightly more than half of the abdomen length. Posterior stomach absent. Anal opening located between the tenth to the thirteenth row of stigmata. Post-abdomen not marked by a constriction. Zooids with well-developed gonads, testicular follicles occupying only the posterior portion of the post-abdomen in a single and double row. Ovary in central position with up to three yellow oocytes of different sizes. The posterior portion of the thorax takes up to two embryos. Larvae with up to 1.30 mm, tail wound around slightly more than half the larvae trunk, dorsal and ventral vesicles in large quantities, three adhesive papillae with long and thin peduncles and four pairs of ampullae.

Remarks. Synoicum pulmonaria is widely distributed in cold waters, but it has never been found in or near the Gulf of Mexico. Moreover, the zooids from colonies collected during the Hourglass Cruises are much smaller than previous descriptions ( Van Name, 1945; Berrill, 1950). Since this species has never been recorded near this region, and considering discrepancies in the zooids sizes, a comparison with reference material is needed to ascertain species identification.

Figures

FIGURE 17.? Synoicum pulmonaria. A—thorax; B—abdomen; C—post-abdomen; D—larvae. Scale: A, B and C = 1 mm; D and E = 0,1 mm.