Dipolydora giardi Mesnil 1896

• Main Authors: Radashevsky, Vasily I., Petersen, Mary E.
• Format: Other/Unknown Material
• Language: unknown
• Published: Zenodo 2005
• Subjects: Biodiversity; Taxonomy; Animalia; Annelida; Polychaeta; Spionida; Spionidae; Dipolydora; Dipolydora giardi; Crassostrea gigas
• Online Access: https://doi.org/10.5281/zenodo.6265801; http://treatment.plazi.org/id/03F7EC34FFA45963FD451D02FAB5FC4A

Dipolydora giardi (Mesnil, 1896) (Fig. 2) Polydora giardi Mesnil, 1896: 195 –202, pl. 13, figs. 1–12. Fauvel, 1927: 50 –52, fig. 17 h–m. Dipolydora giardi : Blake, 1996: 186. [New combination introduced. D. giardi record uncertain]. Material . FRANCE : La Manche, coll. & id. F. Mesnil, accessioned ZMUC 22 June 1896, ZMUC POL­ 653 (3 spec.). ITALY : Ischia Is., Gulf of Naples, 40°44.8' N, 13°56.7' E, 2 m, from shells of the whelks Stramonita haemastoma (L.) and Hexaplex trunculus (L.), coll. V. I. Radashevsky, 18 Jul 1994, BMNH 2002.620–629 (17 spec.). Comparative material . Dipolydora trilobata : RUSSIA : Sea of Japan, Vostok Bay of Peter the Great Bay, 42°53.6' N, 132°44.1' E, from shells of the oyster Crassostrea gigas (Thunberg), ZISP 1/46576­3/46578 (holotype + 19 paratypes); IMBV 1/12171 (50 paratypes); USNM 183520 (30+ spec.). Description . Mesnil’s material consists of three complete individuals 3–4 mm long and 0.3–0.4 mm wide for c. 60, 70, and 75 chaetigers. One individual regenerating two anterior segments. Largest complete specimen from Italy c. 4 mm long and 0.3 mm wide for 60 chaetigers. Body pigmentation absent. Prostomium incised to bifid anteriorly. Caruncle extending posteriorly to end of chaetiger 3. Eyes and nuchal antenna absent (Fig. 2 A). Palps extending posteriorly for 10–15 chaetigers. Chaetiger 1 with postchaetal lamellae in both rami; both noto­ and neurochaetae short capillaries, fewer than in following chaetigers. Posterior notopodia with only capillaries, without spines. Chaetiger 5 greatly modified, larger than chaetigers 4 or 6, without postchaetal lamellae, with 2 or 3 dorsal superior geniculate capillaries (Fig. 2 H), 4 or 5 major spines alternating with bilimbate­tipped companion chaetae (Fig. 2 I), and a tuft of 4 or 5 ventral capillaries (Fig. 2 G). Major spines falcate, with lateral tooth on one side and fine spur or protuberance on the other side; spines arranged in a slightly curved diagonal row; lateral tooth occasionally broken in older spines positioned in anterior ...