Thysanocardia procera (Moebius, 1875)

Açik, Sermin, 2009, Soft-bottom sipunculans in Izmir Bay (Aegean Sea, eastern Mediterranean), Zootaxa 2136, pp. 40-48 : 43

Thysanocardia procera (Moebius, 1875)

Description. Body yellow and yellowish-red in colour, with circular base and rounded point. Trunk 2.5–6.2 mm long, 1.3–1.8 mm wide. Introvert 3.8–16 mm long, 0.5–0.9 mm wide. 7–9 tentacles surrounding bilobed nuchal organ ( Fig. 4 B). Distinct brown line present on oral surface of tentacle ( Fig. 4 B). Papillae on posterior end of trunk 17.5–40 µm height, 10–25 µm in diameter; papillae on anterior part of trunk 17.5–27.5 µm height, 7.5–15 µm in diameter. Contractile vessel with distinct villi. Distance between posterior end of trunk and base of retractors 0.25–1 mm. Retractors originating from 10–16% of distance to end of trunk. Nephridiopores at same level to anus. Nephridia 1–1.5 mm height, 0.2–0.3 mm wide. Trunk 2.5–4.1 times nephridia length.

Ecology. In the study area, this species was found on sandy-mud, muddy-sand and Posidonia oceanica between 15– 30 m.

Distribution. North Atlantic and Mediterranean Sea ( Saiz Salinas & Villafranca Urchegui 1990).

Figures

FIGURE 4. A, Golfingia (G.) vulgaris vulgaris, introvert hook. B, Thysanocardia procera, tentacles surrounding bilobed nuchal organ. C, D, Phascolion (P.) strombus strombus, holdfast papillae (C) and introvert hook (D). E, Onchnesoma steenstrupii steenstrupii, egg in coelomic cavity. F, Aspidosiphon (A.) mexicanus, intestinal coils and spindle muscle. G, Aspidosiphon (A.) muelleri, anal shield. Scale bars: A, 15 µm; B, 0.3 mm; C, 40 µm; D, 20 µm; E, 20 µm; F, 1 mm; G, 0.5 mm.