taxonID	type	description	language	source
DD1587CF4A7FDF31FF0FD6F4AEDDF965.taxon	materials_examined	Material examined. Black Sea: original label ʹ Polydora ciliata (Johnston, 1838) (M. Neagrä) Polychaeta 3 ʹ MNINGA 30.294 (44); Bulgaria: Sta. 190 – 4 / VA 1, Varna (43 ° 08.08 ʹN, 28 ° 02.89 ʹE), 21.8 m, in muddy sand, 23 Mar 2008, coll. A. Teacä, MNINGA PLY 032 (10); Romania: Sta. 66, Danube – Black Sea Canal (44 ° 05 ʹ 61.6 ʹ N, 28 ° 38 ʹ 0 9.1 ʹ E), 3 m, in mud covering artificial rocky substrate, 9 Aug 1999, MNINGA PLY 033 (2); Sta. 78, Agigea (44 ° 01 ʹ 45.6 ʹ N, 28 ° 39 ʹ 32.0 ʹ E), 4 m, in columella of Nassarius reticulatus (Linnaeus, 1758) inhabited by Diogenes pugilator (Roux, 1829), 3 Aug 2003 (1); Sta. 79, Agigea (44 ° 04 ʹ 57.4 ʹ N, 28 ° 38 ʹ 36.3 ʹ E), 4 m, in clayrock, 5 Aug 2003 (41); Sta. BS 07 / MA 07 (43 ° 46.47 ʹN, 28 ° 31.05 ʹE), 33.5 m, in silty mud, 20 Apr 2007, coll. A. Teacä, MNINGA PLY 034 (2); Sta. 177 – 8 / DP 5 (44 ° 35.76 ʹN, 29 ° 11.43 ʹE), 26.2 m, black mud with Melinna palmata Grube, 1870 and Mya arenaria Linnaeus, 1758, 21 Mar 2008, coll. A. Teacä, MNINGA PLY 035 (1); Sta. Ma 08 – 1 Mangalia (43 ° 49 ʹ 14.30 ʹ N, 28 ° 36 ʹ 56.53 ʹ E), 14.2 m, Mytilus galloprovincialis Lamarck, 1819 bank, 11 Jun 2008, coll. A. Teacä, MNINGA PLY 036 (13); Sta. Ma 08 – 2 Mangalia (43 ° 49 ʹ 14.30 ʹ N, 28 ° 36 ʹ 56.53 ʹ E), 14.2 m, Mytilus galloprovincialis bank, 11 Jun 2008, coll. A. Teacä, MNINGA PLY 037 (10); Ukraine: original label ʹ Polydora limicola, Odessa Bayʹ (176); original label ʹ Polydora limicola, Grigorievsky Limanʹ (103); Sta. 159 – 4 / Phy 7 (45 ° 34.13 ʹN, 30 ° 17.38 ʹE), 23.4 m, silty mud with Mytilus shells, 18 Mar 2008, coll. A. Teacä, MNINGA PLY 038 (21).	en	Surugiu, Victor (2012): Systematics and ecology of species of the Polydora - complex (Polychaeta: Spionidae) of the Black Sea. Zootaxa 3518: 45-65, DOI: 10.5281/zenodo.208946
DD1587CF4A7FDF31FF0FD6F4AEDDF965.taxon	description	Description. Specimens up to 20 mm long, 1.25 mm wide at chaetiger 5, with up to 80 chaetigers. Colour in life light tan with red branchiae, palps, and dorsal blood vessels. Preserved specimens pale yellowish. Body not pigmented, but larval pigmentation may persist in recently settled juveniles. Distal part of palps with a diffuse brown pigmentation dispersed along margins of ciliated groove. Pygidium white due to presence of numerous glandular epithelial cells. Prostomium anteriorly bifurcated, flaring laterally, posteriorly prolonged by low narrow caruncle, reaching posterior margin of chaetiger 3 (Fig. 2 A). Cirriform, anteriorly oriented occipital antenna present on caruncle between notopodia of chaetiger 1. Four black, rounded eyes in trapezoidal arrangement; anterior pair slightly larger and further apart. Lateral sides of caruncle with large ciliary bands. Palps long, extending posteriorly to chaetiger 20, prehensile, with a distinct longitudinal ciliated groove. Chaetiger 1 with long, relatively slender cirriform notopodial lamellae; notochaetae absent; neuropodial postchaetal lamellae shorter, conical, with short capillaries (Fig. 2 B). Chaetigers 2 – 4 and 6 with well-developed parapodial lobes and postchaetal lamellae, with ventral and dorsal bundles of limbate capillary chaetae (Fig. 2 B). Chaetiger 5 larger than adjacent segments (Fig. 2 A), overlapping chaetiger 6 dorsally, with 5 – 10 major modified spines alternating with delicate companion chaetae, both arranged in a straight or slightly curved horizontal or oblique row (Fig. 2 B). Major modified spines of chaetiger 5 falcate, with distinct lateral tooth and narrow slender subdistal longitudinal flange or keel situated laterally on main fang distal to lateral tooth (Fig. 2 C). Companion chaetae slender, feather-like, often distally bifurcated, depending on wear, closely adhering to convex side of major spines (Fig. 2 C). Postchaetal lamellae absent. Dorsal superior and ventral inferior capillaries on chaetiger 5 absent. Ventral bidentate hooded hooks (Fig. 2 E) from chaetiger 7, without any accompanying capillaries. Main fang of hook at right or slightly acute angle to shaft, with narrow angle (~ 25 °) between apical tooth and main fang. Shaft of hooks slightly curved, with prominent constriction and distinct manubrium. Chaetiger 7 with 5 – 8 hooks, following chaetigers with up to 12 hooks arranged in vertical series; number of hooks decreases to about three on last few chaetigers. No special notochaetae on posterior segments. Branchiae digitiform, long, thin, from chaetiger 7, continuing posteriorly to last few posterior segments, free from notopodial postchaetal lamellae (Fig. 2 B). Pairs of branchiae meeting middorsally, with lengths gradually decreasing posteriorly. Pygidium large, disc-like, with weakly glandular surface; anus located below narrow middorsal gap (Fig. 2 F). Habitat and ecology. Polydora cornuta occurs on various types of substrata (rocks, stems of reeds, watersoaked branches of bushes, seagrasses, clayrock, soft mud, sandy mud or sand) on which it builds fragile tubes of silt particles and fine sand grains. Tubes are brownish-yellowish, made from fine sand grains and detritus, up to 20 mm long and quite large enough to permit the animal to turn around 180 ° and reverse direction. The species prefers stagnant near-shore, eutrophicated water, rich in detritus and biogenic elements, 0 – 33.5 m. On hard substrates the species is frequently found on silted surfaces, in cracks of stones, between individual mussels or in empty tests of Amphibalanus improvisus (Darwin, 1854) filled with silt. Worms removed from tubes crawl actively. In clayrock the worm digs U- or Y-shaped burrows, lined by a membranous sheath, with densities up to 110,000 ind. m – 2. This species was also found in the apical part of the columella of Nassarius reticulatus shells inhabited by the hermit crab Diogenes pugilator. Polydora cornuta is an opportunistic species. In areas subjected to severe disturbance and organic enrichment the species forms dense tube-mats that can reach densities up to 150,000 ind. m – 2. This species is also a major component of the fouling of bottoms of ships and harbour installations. The species is also tolerant of reduced salinities; at the Romanian Black Sea coast it occurs at salinities ranging between 6.4 – 17.9 PSU. Reproduction and development. Brooding females with large, slightly oval oocytes (80 – 100 μm), were observed in the coelomic cavity from April to August. Oocytes are deposited inside the maternal tube in special egg capsules and attached side-by-side in a loose beadlike string. The capsules are thin-walled, translucent, and attached to the inside wall of the tube by two thin extensions. Each capsule contains between 37 and 57 eggs, with up to 30 capsules per string. The larvae hatch at the 3 - chaetiger stage and immediately start to swim in the water column. Late nectochaetes have two large ramified melanophores situated between median and lateral eyes. Dorsal pairs of transverse bands of pigment are present on chaetigers 3 – 7; from chaetiger 8 onwards they became ramified and stellate-shaped. Juveniles with 12 – 17 chaetigers, less than 2 mm long were observed in benthic samples from June to October. These early juveniles still possessed five pairs of band-shaped chromatophores, followed by pairs of large branching chromatophores on the dorsal surface.	en	Surugiu, Victor (2012): Systematics and ecology of species of the Polydora - complex (Polychaeta: Spionidae) of the Black Sea. Zootaxa 3518: 45-65, DOI: 10.5281/zenodo.208946
DD1587CF4A7FDF31FF0FD6F4AEDDF965.taxon	distribution	Distribution. Polydora cornuta (often reported as P. l i g n i) has a worldwide distribution from temperate to tropical regions. The species has been reported from the Pacific (Blake 1975; Kudenov 1982; Radashevsky 2005; Blake & Ruff 2007) and Atlantic coasts of North America (Blake 1971; Kudenov 1982; Radashevsky 2005), Gulf of Mexico (Rice & Simon 1980; Radashevsky 2005; Rice et al. 2008), Caribbean Sea (Foster 1971), coasts of Brazil and Argentina (Radashevsky 2005), southeastern Australia (Blake & Kudenov 1978), Sea of Japan (Sato- Okoshi 2000; Radashevsky 2005), Yellow Sea (Radashevsky 2005), Taiwan and China (Radashevsky & Hsieh 2000; Zhou et al. 2010), Baltic Sea (Ramberg & Schram 1983), Kattegat and Öresund (Hartmann-Schröder 1996), North Sea (Böggemann 1997), western Mediterranean Sea (Tena et al. 1991), Aegean Sea (Çinar et al. 2005; Ergen et al. 2006; Simboura et al. 2008), Sea of Marmara (Daġli & Ergen 2008; Karhan et al. 2008; Çinar et al. 2011), Bosphorus Strait (Karhan et al. 2008), and? Sea of Azov (Kisseleva 1987). In the Black Sea the species was recorded from the coasts of Romania (Surugiu 2005 a), Bulgaria (Todorova & Panayotova 2006), southern Crimea (Boltachova & Lisitskaya 2007), northern Caucasus (Selifonova 2011 a), Odessa region (Losovskaya 2011) and in front of the Danube Delta (Bondarenko 2011) (Fig. 1).	en	Surugiu, Victor (2012): Systematics and ecology of species of the Polydora - complex (Polychaeta: Spionidae) of the Black Sea. Zootaxa 3518: 45-65, DOI: 10.5281/zenodo.208946
DD1587CF4A7FDF31FF0FD6F4AEDDF965.taxon	discussion	Remarks. Polydora cornuta specimens from the Black Sea agree with recent morphological descriptions provided by Blake and Maciolek (1987) and Radashevsky (2005). Radashevsky (2005) examined adult and larval morphology of P. cornuta from different parts of the world and concluded that variability is not sufficiently consistent to separate different geographic populations into additional species and that P. cornuta represents a single species. Rice et al. (2008), however, using molecular, reproductive morphology, and cross fertilization experiments were able to demonstrate the existence of genetically distinct and reproductively isolated North American populations from California, Florida and Maine, and clearly demonstrated that at least three cryptic species exist. Earlier studies by Rice and Simon (1980) and Rice (1991) provide additional evidence of incipient sibling speciation in this widely distributed spionid polychaete.	en	Surugiu, Victor (2012): Systematics and ecology of species of the Polydora - complex (Polychaeta: Spionidae) of the Black Sea. Zootaxa 3518: 45-65, DOI: 10.5281/zenodo.208946
DD1587CF4A78DF3CFF0FD2B7AE5BFB15.taxon	materials_examined	Material examined. Black Sea: “ Polydora ciliata (Johnston, 1838) (M. Neagrä) Polychaeta 3 ” MNINGA 30.294 (12); Romania: Sta. AG 13, Agigea, 10 m, scrapings from Mytilus galloprovincialis bank, 1 Sep 2004, MNINGA PLY 039 (1); Sta. AG 34, Agigea, 4 m, scrapings from M. galloprovincialis bank, 16 Apr 2005, MNINGA PLY 040 (2); Sta. 99, Eforie Sud (44 ° 01 ʹ 15.7 ʹ N, 28 ° 38 ʹ 36.9 ʹ E), limestone plate covered with mud near sewage outflow, 1.5 m, 5 Aug 2005 (100 +); Sta. AG 47, Agigea, 14 m, scrapings from M. galloprovincialis bank, 23 Oct 2005, MNINGA PLY 041 (6); Sta. AG 48, Agigea, 12 m, scrapings from M. galloprovincialis bank, 23 Oct 2005, MNINGA PLY 042 (1); Sta. AG 52, Agigea, 4 m, scrapings from M. galloprovincialis bank, 23 Oct 2005, MNINGA PLY 043 (2); Ukraine: southern Crimea, Katsiveli (44 ° 23 ʹN, 33 ° 58 ʹ E), on long-line farmed Crassostrea gigas (Thunberg, 1793) shells, 2.5 – 3.5 m, salinity 17.9 – 18.6 ‰, 29 Jun 2011, coll. / det. E. Lisitskaya (31).	en	Surugiu, Victor (2012): Systematics and ecology of species of the Polydora - complex (Polychaeta: Spionidae) of the Black Sea. Zootaxa 3518: 45-65, DOI: 10.5281/zenodo.208946
DD1587CF4A78DF3CFF0FD2B7AE5BFB15.taxon	description	Description. Adult worms up to 20 mm long, 1.1 mm wide at chaetiger 5 and with up to 116 chaetigers. Colour in life light tan with red branchiae, palps and blood vessels. Preserved specimens pale yellowish. Dorsal black pigmentation absent in adults. Distal 3 / 4 – 2 / 3 of palps with a dark brown, almost black sinuous line along edges of ciliated food groove, persisting in preserved specimens. Pygidium white in colour due to presence of numerous glandular epithelial cells. Prostomium with anterior margin slightly incised, caruncle extending back to posterior end of chaetiger 2 (Fig. 3 A). Occipital antenna absent. Eyes usually absent in adults; juveniles with 1 – 4 small rounded eyes in trapezoidal arrangement, with anterior pair slightly larger and further apart. Lateral sides of caruncle with narrow ciliated grooves. Two long, easily detachable palps present, capable of extending to chaetiger 15. Chaetiger 1 only with well-developed neuropodial postchaetal lamellae and a fascicle of capillary neurochaetae; notopodium represented by small notopodial lamellae, notochaetae entirely absent (Fig. 3 B). Chaetigers 2 – 4 and 6 with well-developed and flattened noto- and neuropodial postchaetal lamellae, with bundles of limbate capillary chaetae. Modified chaetiger 5 broader and longer than adjacent ones (Fig. 3 A – B), partially covering chaetiger 6, without postchaetal lamellae and bearing an oblique or almost horizontal row of 5 – 6 thick, falcate spines alternating with companion chaetae. Major spines of chaetiger 5 falcate, distally curved and with broad, subterminal flange on concave side (Fig. 3 C). Companion chaetae slender, pennoned, slightly more ventral and closely adjoining falcate spines (Fig. 3 C – D). Chaetiger 5 with up to six superior dorsal limbate capillary chaetae arranged in vertical row (Fig. 3 C – D) and compact bundle of inferior ventral shorter limbate capillaries. Neuropodial bidentate hooded hooks from chaetiger 7, up to 11 in a vertical row in middle chaetigers, decreasing to 2 – 3 posteriorly, without alternating or inferior capillaries on anterior and posterior chaetigers. Hooded hooks with main tooth at right / acute angle to shaft and with wide acute angle (~ 40 °) to smaller apical tooth; with a prominent constriction and distinct manubrium on shaft. Posterior notopodia with slender winged and non-winged capillaries, without special notopodial spines. Branchiae digitiform, elongated, overlapping middorsally (Fig. 3 E), from chaetiger 7, small at first, reaching maximum length by chaetiger 9 – 10, and continuing to near the posterior end, absent from last 10 – 16 chaetigers, decreasing gradually in size in posterior half of the body, free from notopodial postchaetal lamellae. Pygidium thin, cup-shaped with weakly glandular surface and with anus at base of dorsal gap (Fig. 3 F). Habitat and ecology. Polydora websteri is a common borer in limestone from the splash zone to the lowest limit of the rocky seabed (~ 20 m). The burrows of P. w e b s t e r i are pear-shaped or sacciform, non-branching, and large enough for the worm to turn and reverse direction. The gallery is lined by a membranous sheath that extends outside the burrow by about 2 – 3 mm. In areas influenced by sewage discharge, the intense sedimentation of suspended matter covers the substrate in which the worms bore. Under such circumstances the worms will extend their external sheaths well above the substrate, forming dense tube mats that are 2 – 3 cm thick. Maximum recorded density of this species was 132,500 ind. m – 2 at a depth of 0.5 m. The salinity range for this worm in the Black Sea is 9.2 – 17.8 PSU. Reproduction and development. According to Lisitskaya et al. (2010) eggs, each measuring 130 – 150 µm in diameter, were deposited in transparent, elastic, oval-shaped egg capsules 900 µm long and 850 µm wide starting from February. Egg capsules contained 50 – 75 eggs and were attached, side-by-side, to the interior wall of the burrow by a thin, 250 - µm long stalk. Only 10 – 15 % of the eggs in the capsule were fertilized, the remainder representing nurse eggs. Adelphophagic larvae reared in the laboratory from May to June left the capsules at the 5 – 6 to 12 – 13 chaetigers stage and started to swim in the water column. The larvae settled at the 17 – 18 chaetiger stage. In coastal waters of Crimea planktic larvae of P. websteri were present from May to November (E. Lisitskaya 2012, pers. comm.).	en	Surugiu, Victor (2012): Systematics and ecology of species of the Polydora - complex (Polychaeta: Spionidae) of the Black Sea. Zootaxa 3518: 45-65, DOI: 10.5281/zenodo.208946
DD1587CF4A78DF3CFF0FD2B7AE5BFB15.taxon	distribution	Distribution. Polydora websteri is present in areas where there are cultured edible oysters, especially Crassostrea gigas (Read 2010; Lisitskaya et al. 2010). The worldwide distribution of this species includes the Atlantic (Blake 1971) and Pacific coasts of North America (Hartman 1961; Blake 1996), Gulf of Mexico (Hartman 1951), Caribbean Sea (Foster 1971), Hawaii, Atlantic (Pagliosa 2005) and Pacific coast of South America (Blake 1983); Japan (Sato-Okoshi 1999), southeastern Australia (Blake & Kudenov 1978), and New Zealand (Read 2010). In the Black Sea known records are for coasts of Romania (Surugiu 2005 a) and southern Crimea (Lisitskaya et al. 2010).	en	Surugiu, Victor (2012): Systematics and ecology of species of the Polydora - complex (Polychaeta: Spionidae) of the Black Sea. Zootaxa 3518: 45-65, DOI: 10.5281/zenodo.208946
DD1587CF4A78DF3CFF0FD2B7AE5BFB15.taxon	discussion	Remarks. The Black Sea specimens are in good agreement with the description of the type material (Radashevsky 1999). Polydora websteri is very close in morphology to P. haswelli and P. neocaea Williams & Radashevsky, 1999 by having a flange on the major spines of chaetiger 5. However, P. w e bs t e r i can be distinguished from P. haswelli and P. neocaea by pigmentation pattern (Read 2010). Thus palps of P. w e b s t e r i are characterized by continuous black lines along the margins of the ciliated groove, whereas in P. h a s w e l l i and P. neocaea the palps have distinct bands of black pigment. Additionally, dorsal pigmentation is absent in P. w e b s t e r i, whereas in P. h a s w e l l i and P. neocaea there is a conspicuous black pigmentation on the lateral sides of the prostomium and first anterior segments. Slight differences exist also with regard to the shape of the flange on major spines, which is broader, shorter, and almost terminal in P. w e b s t e r i (Fig. 3 C) and is narrower, longer, and subterminal in P. neocaea and P. haswelli (Williams & Radashevsky 1999: Fig. 3 A; Read 2010: Fig. 2 C, Fig. 4 A – C). As noted by Radashevsky et al. (2006) and Read (2010), P. neocaea may be a synonym of P. haswelli.	en	Surugiu, Victor (2012): Systematics and ecology of species of the Polydora - complex (Polychaeta: Spionidae) of the Black Sea. Zootaxa 3518: 45-65, DOI: 10.5281/zenodo.208946
DD1587CF4A75DF3FFF0FD105AF46FDE5.taxon	materials_examined	Material examined. Bulgaria: Sta. 190 – 4 / VA 2, Varna (43 ° 08.17 ʹN, 28 ° 14.41 ʹE), 33.7 m, muddy seabed, 23 Mar 2008, coll. A. Teacä, MNINGA PLY 044 (46); Romania: Sta. 89, Eforie Nord, 10 m, medium-grained sand, 20 Aug 2003, coll. V. Abaza (1); Sta. 91, Tuzla, 10 m, sand mixed with shell debris, 20 Aug 2003, coll. V. Abaza (6); Sta. BS 07 / MA 07 (43 ° 46.47 ʹN, 28 ° 31.05 ʹE), 33.5 m, silty mud, 20 Apr 2007, coll. A. Teacä, MNINGA PLY 045 (2); Sta. BS 05 / 66 (44 ° 13.37 ʹN, 29 ° 38.03 ʹE), 60.3 m, mud with Modiolula phaseolina (Philippi, 1844), 10 Aug 2007, coll. A. Teacä, MNINGA PLY 046 (2); Sta. BS 05 / 01 (44 ° 19.29 ʹN, 29 ° 30.27 ʹE), 56 m, greenish-grey mud with Mytilus galloprovincialis and M. phaseolina shells, 11 Aug 2007, coll. A. Teacä, MNINGA PLY 047 (99); Sta. BS 05 / 03 (44 ° 19 ʹ 27 ʹ N, 29 ° 33 ʹ 35 ʹ E), 54.5 m, mud with M. phaseolina, 11 Aug 2007, coll. A. Teacä, MNINGA PLY 048 (357); Sta. BS 05 / 28 (44 ° 11.29 ʹN, 29 ° 40.57 ʹE), 60.6 m, mud with M. phaseolina, 11 Aug 2007, coll. A. Teacä, MNINGA PLY 049 (3); Sta. S – RO 1 – 02 Portiţa (44 ° 38.482 ʹN, 29 ° 39.845 ʹE), 50.1 m, black muds with Melinna palmata and Mya arenaria, 7 Apr 2008, coll. A. Teacä, MNINGA PLY 050 (114); Sta. BS 08 / 91 – 1 (43 ° 50 ʹ 29.43 ʹ N, 29 ° 15 ʹ 27.68 ʹ E), 62.5 m, mud with M. phaseolina, 21 Jun 2008, coll. A. Teacä, MNINGA PLY 051 (2); Sta. BS 08 / 05 (43 ° 59 ʹ 31.00 ʹ N, 29 ° 21 ʹ 31.18 ʹ E), 56 m, greenish-grey mud with Mytilus and Modiolula shells, 22 Jun 2008, coll. A. Teacä, MNINGA PLY 052 (92); Sta. BS 08 / 45 – 1 (43 ° 55 ʹ 29.71 ʹ N, 29 ° 21 ʹ 24.84 ʹ E), 59.8 m, greenish-grey mud with Mytilus and Modiolula shells, 22 Jun 2008, coll. A. Teacä, MNINGA PLY 053 (9); Sta. BS 08 / 22 (43 ° 57 ʹ 31 ʹ N, 29 ° 17 ʹ 81 ʹ E), 55.3 m, greenish-grey mud with Mytilus and Modiolula shells, 23 Jun 2008, coll. A. Teacä, MNINGA PLY 054 (5); Ukraine: Sta. 140 – 3 / Phy 4 a (45 ° 39.11 ʹN, 31 ° 20.78 ʹE), 46.1 m, pelitic sand with shell rubble and Phyllophora, 15 Mar 2008, MNINGA PLY 055 (3); Sta. 156 – 2 / DN 10 (45 ° 26.95 ʹN, 30 ° 59.28 ʹE), 45.5 m, pelitic sand with shell rubble and Phyllophora, 17 Mar 2008, MNINGA PLY 056 (287); Sta. 159 – 4 / Phy 7 (45 ° 34.13 ʹN, 30 ° 17.38 ʹE), 23.4 m, silty mud with Mytilus shells, 18 Mar 2008, MNINGA PLY 057 (2).	en	Surugiu, Victor (2012): Systematics and ecology of species of the Polydora - complex (Polychaeta: Spionidae) of the Black Sea. Zootaxa 3518: 45-65, DOI: 10.5281/zenodo.208946
DD1587CF4A75DF3FFF0FD105AF46FDE5.taxon	description	Description. Up to 15 mm long, 0.75 mm wide at chaetiger 5, with up to 90 chaetigers. Colour of preserved worms pale yellowish. Body without dorsal pigmentation. Prostomium more or less distinctly incised anteriorly, forming two rounded lobes; caruncle indistinct, extending to posterior end of chaetiger 3 (Fig. 4 A). Occipital antenna absent. Eyes usually absent in adults; juveniles with four eyes arranged in nearly straight transverse row with the outer pair larger and irregular in shape. Nuchal organs as long, narrow ciliary bands on lateral sides of caruncle. Palps long, flexible, with prominent ciliated groove, extending posteriorly to chaetiger 15. Chaetiger 1 biramous, with well-developed podial lobes, carrying both short notopodial capillaries and more numerous neuropodial capillaries (Fig. 4 A). Chaetigers 2 – 4 and 6 with noto- and neuropodial fascicles of winged capillary chaetae (Fig. 4 A – B). Notochaetae arranged in two vertical rows of shorter and thicker capillaries plus a dorsal superior tuft of longer and thinner capillaries. Neurochaetae also as two vertical rows of thick capillaries and a ventral inferior tuft of thinner and shorter capillaries. Number of capillary notochaetae diminishing toward posterior end. In far posterior notopodia capillaries completely replaced by stout, sharply pointed spines arranged in semicircular row (Fig. 4 E – F); number of spines increasing from 1 – 3 in a tuft up to 16, providing a spinous appearance to posterior end. Chaetiger 5 modified, larger than adjacent segments, without postchaetal lamellae and carrying a horizontal curved row of 4 – 6 large spines (Fig. 4 A – B). Modified spines of chaetiger 5 falcate, distally curved, with two nearly equal teeth and a tuft of fine bristles in concavity between teeth. Companion chaetae absent (see Remarks). Dorsal superior fascicle of chaetiger 5 with up to seven geniculate limbate chaetae arranged in a vertical or oblique row (Fig. 4 C – D); ventral inferior fascicle as compact tuft of up to 9 winged capillaries. Neuropodial bidentate hooded hooks, up to six in vertical row from chaetiger 7. Main fang of hook at obtuse angle to shaft and at reduced angle to distal smaller tooth. Shafts of hooks strongly curved, without constriction and manubrium. In anterior neuropodia up to four inferior capillaries present ventral to hooks. In posterior neuropodia inferior capillaries diminishing in number, becoming narrow and non-winged. Branchiae from chaetiger 7, short at first, reaching full size by chaetiger 10 – 12, absent from posterior third of body, not connected to notopodial lobes. Pygidium with four subequal lobes (Fig. 4 F). Habitat and ecology. On the Romanian coast D. quadrilobata is found in soft sediments (fine sand, muddy sand, sandy mud, silty mud, and mud) at 10 – 100 m. However, the species is most common and abundant between 40 – 60 m in mud between beds of Modiolula phaseolina, with densities up to 2600 ind. m – 2. The worm constructs permanent tubes that stand erect in the substrate, extending 15 – 20 mm. Tubes straight, up to 40 mm long and 1.5 mm wide, built of fine sand grains bound by silt and detrital particles. The upper part of tube is smooth and greyish-brown in colour, while the lower part, buried in sediment, is coarser and rusty-coloured. Reproduction and development. Not known to date in the Black Sea.	en	Surugiu, Victor (2012): Systematics and ecology of species of the Polydora - complex (Polychaeta: Spionidae) of the Black Sea. Zootaxa 3518: 45-65, DOI: 10.5281/zenodo.208946
DD1587CF4A75DF3FFF0FD105AF46FDE5.taxon	distribution	Distribution. Arctic-boreal species, reported from the Pacific (Blake 1996) and Atlantic coasts of North America (Blake 1971), Sea of Japan and Sea of Okhotsk (Sato-Okoshi 2000), Bering Sea (Uschakov 1955; Radashevsky 1993), White Sea (Khaitov et al. 1999); North Sea (Rasmussen 1973; Hartmann-Schröder 1996), British Channel, Kiel Bay, Baltic Sea, Atlantic coast of Europe (Fauvel 1927), Adriatic Sea (Castelli et al. 1995; Požar-Domac 1978) and Black Sea (Todorova & Panayotova 2006).	en	Surugiu, Victor (2012): Systematics and ecology of species of the Polydora - complex (Polychaeta: Spionidae) of the Black Sea. Zootaxa 3518: 45-65, DOI: 10.5281/zenodo.208946
DD1587CF4A75DF3FFF0FD105AF46FDE5.taxon	discussion	Remarks. There is little confusion regarding the taxonomic position of Dipolydora quadrilobata. This species is closely related to D. caulleryi in having heavy, protruding, awl-shaped notopodial spines in far posterior segments and a pygidium divided into four nearly equal lobes, both falling into the ʹ armata / caulleryi ʹ subgroup (sensu Blake 1996). Söderström (1920) even considered D. quadrilobata to be a juvenile of D. caulleryi. Nevertheless, Dipolydora quadrilobata is unique among species of the Polydora complex by having modified spines of chaetiger 5 expanded distally into two nearly equal teeth with a bushy tuft of fine bristles between them, and by four eyes arranged in a nearly straight transverse row (Blake 1996). The Black Sea specimens match the morphological descriptions of specimens from northern Europe (Hartmann-Schröder 1996) or from northern Pacific (Radashevsky 1993). However, brown reticulated pigmentation on anterior end of body reported by many authors (Fauvel 1927; Blake 1971, 1996; Radashevsky 1993; Hartmann-Schröder 1996) was absent in the Black Sea specimens. Sato-Okoshi (2000), however, indicates that in Japan this pigmentation was present only in some specimens. Also, in one individual were observed two limbate capillaries near the bases of the major spines of chaetiger 5, like normal companion chaetae (Fig. 4 D).	en	Surugiu, Victor (2012): Systematics and ecology of species of the Polydora - complex (Polychaeta: Spionidae) of the Black Sea. Zootaxa 3518: 45-65, DOI: 10.5281/zenodo.208946
