Pseudochitinopoma beneliahuae

Description. TUBE: white, about 0.8 mm (up to 1.2) mm wide with lumen of about 0.3 (max. 0.5) mm. Semicircular to circular in cross-section, attached to substrate throughout its entire length, and bearing more or less regularly spaced sausage-like transverse ridges alternating with tube parts having central longitudinal keels (Fig. 3 A – C) sometimes supplemented with two indistinct accessory lateral keels. Hyaline / opaque granular layers absent. BRANCHIAE: each lobe with 4 – 5 pairs of radioles, arranged in semicircles to pectinately, not connected by interradiolar membrane. Pinnules long; terminal filaments short, anteriorly not extending beyond the remaining pinnules. Section of radioles subtriangular. Branchial eyes not observed. PEDUNCLE: smooth, subtriangular to circular in cross-section, only slightly thicker than radioles, inserted at base of left branchial lobe, in front of first radiole or almost midway between branchial lobes. Showing slight constriction just below operculum. OPERCULUM: ampulla terminating in elongated, slightly pointed chitinous cap with many partitions (or very fine numerous horizontal striations, Figs 3 D, 5 C). Length of the operculum about 0.5 mm, width 0.3 mm. COLLAR AND THORACIC MEMBRANES: collar relatively high, covering bases of branchial lobes with slightly laciniate edge; continuous with short thoracic membranes, ending at chaetiger 2. THORAX: with collar chaetiger and five uncinigerous chaetigers (a juvenile from 7770 with four chaetigers only). Collar chaetae of two types: limbate and typical fin-and-blade chaetae with almost single row of teeth in the basal fin not separated from the blade (Figs 4 A, 5 D). Subsequent chaetae limbate, of two sizes (Figs 4 B – C, 5 E). Apomatus - chaetae absent. Uncini along entire thorax saw-shaped, with 9 – 10 curved teeth, with flat blunt, slightly gouged, anterior peg (dental formula P: 1: 1: 1: 1: 1: 1: 1: 1: 1: 1, Fig. 4 D, 5 G). In fresh material from Eilat (7768) two rows of six prostomial eyespots, black, were observed, invisible in preserved material. ABDOMEN: abdominal chaetigers up to 70. Uncini rasp-shaped with 3 – 4 rows of teeth, with flat blunt, slightly gouged, anterior peg and 10 – 11 teeth in side view (dental formulae e. g. P: 4: 3: 3: 3:? :::::, P: 3: 4: 3: 4: 3:? ::::; all apices obscured by epidermal fold and represented by:?:? :::: in the formulae, Figs 4 E, 5 H). Chaetae true trumpet-shaped, hollow bordered with two rows of teeth (Figs 4 F, 5 F). Capillary chaetae absent in posterior chaetigers. Pygidium bilobed. SIZE: length up to 6 mm, generally about 5 mm. Width of thorax 0.2 – 0.3 mm. Branchiae and operculum 2 mm long. COLOUR: opercular cap yellow to brown, radioles and thorax orange, abdomen hyaline with orange gut (Eilat HUJ-INV-Poly 1652, 7769); colourless except for white pygidial lobes (Eilat 7768).

Remarks. Pseudochitinopoma beneliahuae sp. nov. has a very distinct tube structure, with more or less regularly spaced sausage-like transverse ridges alternating with tube parts having central longitudinal keels. Transverse ridges, although very different in shape, are also known only for P. amirantensis sp. nov. (see above). Both P. beneliahuae sp. nov. and P. amirantensis sp. nov. also have only six thoracic chaetigerous segments, unlike the rest of species in the genus that have seven. However, length of collar and thoracic membranes, and especially opercular morphologies, are very different in these two species (see Table 1). Tubes are often encrusted by calcareous algae.

Distribution. Red Sea: Gulf of Eilat; Indian Ocean: Western Australia, 10 – 80 m. Reproduction. Unknown.

Etymology. The species is named after our friend and colleague Dr. Nechama Ben-Eliahu in recognition of her numerous and important contributions to serpulid taxonomy.

Material studied. Western Australia, NE of Monte Bello Islands, 20 ° 20 ' S, 115 ° 41 ' E – 20 ° 21 ' S, 115 ° 39 ' E, 55 – 53 m, Otter trawl, R / V “ Soela ” Stn 001 – 0040, legit S. Slack-Smith & L. Marsh, 5 December 1979, from tube of Protula bispiralis, det. H. A. ten Hove 1986 [Pseudovermilia nov. spec., redet. 1990 Pseudochitinopoma nov. spec.], (WAM V 7919, holotype and 2 paratypes V 7920 - 7921; ZMA V. Pol. 3573, five paratypes, tubes; AM W. 41139, two paratypes); approximately 20 ° 00 – 03 ' S, 115 ° 58 – 57 ' E, 78 – 80 m, Otter trawl, R / V “ Soela ” Stn 001 – 0012, legit S. Slack-Smith & L. Marsh, 2 December 1979, det. H. A. ten Hove 1986 [Pseudovermilia nov. spec., redet. 1990 Pseudochitinopoma nov. spec.] (WAM V 2244 (113 – 86, 1 spec, tubes); approximately 20 ° 00 – 03 ' S, 115 ° 58 – 57 ' E, 78 – 80 m, Otter trawl, R / V “ Soela ” Stn 001 – 0012, legit S. Slack-Smith & L. Marsh, 2 December 1979, det. H. A. ten Hove 1986 [Pseudovermilia nov. spec., redet. 1990 Pseudochitinopoma nov. spec.] (WAM V 2226 (95 – 86, 10 specs, tubes); Dampier Archipelago, North of Malus Island, 19 ° 45 ' S, 116 ° 38 ' E – 19 ° 44 ' S, 116 ° 40 ' E, 57 – 60 m, Otter trawl, R / V “ Soela ” Stn 001 – 0028, legit S. Slack-Smith & L. Marsh, 4 December 1979, det. H. A. ten Hove 1986 [Pseudovermilia nov. spec., redet. 1990 Pseudochitinopoma nov. spec.], from mollusc shell (AM W 42256 - W 42258, 2 specs, prepared for SEM). Israel, Eilat, 29 ° 31 ' N, 34 ° 36 ' E [all Israel coordinates taken from Google Earth, HAtH], on pier of Oil Port, 22 – 25 m, legit, det. H. A. ten Hove, 6 June 1990 [Pseudochitinopoma nov. spec.] (HUJ - INV-Poly 7768, 2 specs, RMNH Vermes 19900, 2 specs); 29 ° 30 ' N, 34 ° 35 ' E, in front of Marine Biology Laboratory, 20 – 25 m, 4 June 1990, legit, det. H. A. ten Hove [Pseudochitinopoma nov. spec.] (HUJ - INV-Poly 1652, 7769, 1 specs, prepared for SEM); 29 ° 30 ' N, 34 ° 35 ' E, in front of Marine Biology Laboratory, S, sandy with scarce coral heads, coral debris, 10 – 18 m, legit, det. H. A. ten Hove, 3 June 1990 [Pseudochitinopoma nov. spec.] (HUJ - INV-Poly 7770, 2 specs, 1 juvenile). FIGURE 4. Pseudochitinopoma beneliahuae sp. nov. HUJ - INV-Poly 1652, SEM, A — special collar chaetae, B — simple collar chaetae, C — thoracic chaeta of the 4 th segment, D — thoracic uncini of the 3 rd segment, E — abdominal uncini of the 6 th segment, F — abdominal chaeta of posterior segments. Scale: A – C — 10 µm, D, E — 5 µm, F — 2 µm. FIGURE 5. Pseudochitinopoma beneliahuae sp. nov. AM W 42256 - W 42258, SEM, A — lateral view of thorax, B — dorsal view of thorax, C — operculum, D — special collar chaetae, E — thoracic chaetae of 2 nd segment, F — abdominal chaeta, G — thoracic uncini, H — abdominal uncini. Scale: A – B — 100 µm, C — 100 µm, D – E – 10 µm, F – H — 5 µm.