The genus Euchone (Polychaeta, Sabellidae) in the Mediterranean Sea, addition of two new species and discussion on some closely related taxa Author Giangrande, Adriana Author Licciano, Margherita text Journal of Natural History 2006 2006-09-28 40 21 - 22 1301 1330 http://dx.doi.org/10.1080/00222930600901458 journal article 10.1080/00222930600901458 1464-5262 5227756 Euchone rosea Langerhans, 1884 ( Figure 5 ) Examined material Seven individuals from Brindisi, 25 m depth , on coralligenous deposits, PCZL . Re-description Small worms with eight thoracic and 14 abdominal chaetigers of which six form the anal depression. Branchial crown length 1.5 mm ; total thorax–abdomen length 5 mm ; maximum width 0.5 mm . Branchial lobes each with five fully developed radioles with palmate membrane for about three-quarters of their length; radiolar flanges present distal to palmate membrane; radioles terminating as flanged filaments ( Figure 5A ). Dorsal lips pointed ( Figure 5A ). Radiolar appendages not observed. Ventral lips not observed; several pairs of ventral radiolar appendages. Collar high, with a slight ventral incision and a middorsal gap ( Figure 5A, B ). Collar terminating at about the same level of the insertion of branchial lobes. Only the collar and first chaetiger stained ( Figure 5A ). Notopodia in chaetiger 1 with six narrowly hooded chaetae. Notopodial fascicles from chaetigers 2–8 with superior group of three elongate narrowly hooded chaetae and inferior group with five paleate chaetae posteriorly and five bayonet-type anteriorly. Paleate chaetae with long tip ( Figure 5F ). Neuropodial uncini five per torus, with small teeth of similar size over the main fang ( Figure 5D ). Abdominal neuropodial fascicles with modified, elongate narrowly hooded chaetae. Notopodia with seven avicular uncini, with main fang surmounted by few rows of small teeth ( Figure 5G ); uncini of the anal depression 10 in number and with a larger number of teeth over the main fang (rasp-shaped) ( Figure 5H ). Intratorus variation present. Anal depression formed by six chaetigers, with wings fully developed with quite raised medial margin, slightly incised in the uppermost part ( Figure 5C ). Remarks This is one of the two Euchone species listed in Fauvel (1927) , but at that time not yet recorded in the Mediterranean Sea. Our material corresponds well to the original description of specimens from Madeira ( Langerhans 1884 ). In the Mediterranean Sea the species has been reported by Albertelli et al. (1983) for the Ligurian Sea and by Cantone and Fassari (1982) for the Gulf of Catania (Ionian Sea). All the published data relate to soft sediments. By contrast, Fauvel (1927) reports the species as typical of coralligenous habitats. Only the specimens present in our collection, coming from the South Adriatic Sea and here re-described, have been collected from coralligenous habitats, thus it is possible that the other records represent a different taxon. Figure 5. (A–D, F–H) Euchone rosea : (A) staining pattern of the anterior end, ventral view; (B) ventral view of the anterior end; (C) lateral and ventral views of the anal depression; (D) thoracic uncinus; (F) thoracic inferior paleate chaeta; (G) abdominal uncinus from the anterior abdominal chaetiger chaetiger; (H) abdominal uncinus from the anal depression region. (E) Euchone rubrocincta : thoracic inferior notochaeta. Habitat Coralligenous deposits. Distribution Atlantic (Madeira), Ireland coasts, Mediterranean Sea.