Semivermilia pomatostegoides ( Zibrowius, 1969 )

Kupriyanova, Elena K., Sun, Yanan, Ten Hove, Harry A., Wong, Eunice & Rouse, Greg W., 2015, Serpulidae (Annelida) of Lizard Island, Great Barrier Reef, Australia, Zootaxa 4019 (1), pp. 275-353 : 317-320

Semivermilia pomatostegoides ( Zibrowius, 1969)

( Figs 22A , 23 )

Vermiliopsis pomatostegoides Zibrowius, 1969: 129 –130, figs 4–10 [Tripoli; original description].

Semivermilia pomatostegoides . —ten Hove 1975: 55, 56, 84 [transferred to Semivermilia ]; Vine & Bailey-Brock 1984: 143 – 144, fig. 3H–I [Red Sea; diagnosis]; Bailey-Brock 1985: 208 –209, fig. 10 [ Fiji; diagnosis]; 1987: 425 [Hawaii; diagnosis]; ten Hove 1993: 83 [ Seychelles; name in list]; 1994: 110 [same]; Gischler & Ginsburg 1996: 582 [ Belize; det. H. ten Hove cf. pomatostegoides ]; Hassan 1997: 52, figure [as S. pomatostgeoides (sic!), Red Sea; diagnosis]; Small et al. 1998: 19 [Caribbean; det. H. ten Hove]; ten Hove & Kupriyanova 2009: 92 [name only].

Material examined. AM W.28452, south of Palfrey Island, sandy, gently sloping, nearly horizontal reef, 14°40'S, 145°28'E, coll. H. ten Hove, 23 Jun 1983, det. H. ten Hove; AM W.45051, MI QLD 2406; AM W.47581, stn.G236, east lagoon near Bird Islet, 9 m, coll. G. Rouse & E. Kupriyanova; AM W.47634 (without tube, used for SEM), Carter Reef, 14°32'S, 145°35'E, coll. P. Hutchings, 10 Mar 1986; AM W.47584, stn.G232, between First Beach and Osprey Island, coral rubble, snorkeling, 1 m, coll. G. Rouse & E. Kupriyanova, 26 Oct 2005; AM W.47635 (as Pseudovermilia , on SEM stub), Granite Head, 14°39'S, 145°27'E, underside of boulders on rock, little sand subtidally, coll. H. ten Hove, 18 Jun 1983; ZMA V.Pol. 4797 (2), stn.16, North Point, sloping reef, mainly dead, slightly silted corals, 3–17 m, coll. H. ten Hove, P. Hutchings & M. Reid, 1 Mar 1986; ZMA V.Pol. 4780 (3), stn.21, south of South Island, 14°42'S, 145°28'E, sloping silty reef, little coral cover, 18–20 m, coll. H. ten Hove & P. Hutchings, 6 Mar 1986; ZMA V.Pol. 4781, Mermaid Cove, on reef, 6–10 m, from crevices in dead coral, coll. H. ten Hove, 20 Jun 1983; ZMA V.Pol. 4805 (as Semivermilia sp.), Turtle Beach, from underside of dead & living corals, fairly cryptic, 6 m, coll. H. ten Hove, 22 Jun 1983.

Diagnosis. Tube white and relatively smooth, triangular in cross section, with a well-defined median ridge, two lateral longitudinal ridges, and broad lateral flanges. Operculum consisting of an ampulla bearing 2–6 chitinous tiers, the most distal may be with a short spine. The ampulla shows a slight swelling medio-ventrally at the junction with the peduncle; in fresh material it is red and clearly an eyespot ( Vine & Bailey-Brock 1984: 144, fig. 3I). Thoracic uncini saw-to-rasp shaped, dental formula P:5:4:4:3:?:? ??, P:4:2:3:?:? ??. Abdominal uncini rasp shaped, with up to 11 rows of 6–2 teeth (not entirely regularly placed).

Remarks. This taxon was described from material from 130 m depth off Tripoli (Mediterranean) as Vermiliopsis pomatostegoides Zibrowius, 1969 , and referred to Semivermilia by ten Hove (1975). It has been recorded commonly from the Mediterranean/Atlantic, but also from diving depths in the Caribbean and Indo- Pacific. Though Zibrowius does not mention the medio-ventral eyespot on the opercular bulb, it was present in material from the Seychelles and from the Netherlands Antilles ( Bonaire; both ten Hove, unpubl.). It remains to be seen if all those far distant populations belong to a single species.

Whether or not Semivermilia parapomatostega Wu & Chen, 1981b (p. 248–249, fig. 2) from the Xisha Islands, South China Sea is a synonym should be decided for a direct comparison of material. The “distinctive” characters given by its authors are not distinctive at all: 5 discs in S. parapomatostega already fall within the range given by Zibrowius for S. pomatostegoides (4–6), the difference between a terminal spine and the bulge figured by Zibrowius is minor as well as the width of the columella. The nature of the square blocks figured on the mid-dorsal keel of S. parapomatostega is unclear, a “longitudinal row of subcircular processes” according to Wu & Chen, 1981b has the feeling of an irregularly growth of a median keel.

Reproduction. One specimen (ZMA V.Pol. 4797) shed eggs, embryos and actively swimming 3 chaetiger trochophore larvae, when the tube was accidentally opened.

Distribution. Mediterranean Sea, East and West (sub)tropical Atlantic, Seychelles, Red Sea,? South China Sea; Qld, Australia. A new record for Australia.

Remarks. The species is so similar in the shape of the operculum to S. uchidai that they are difficult to distinguish. The two species can only be separated by the shape of their tubes, which bear three longitudinal keels in both species, but the lateral keels are high and oblique in S. uchidai , and are shallowly blunt in S. pomatostegoides .

Figures

FIGURE 23. Semivermilia pomatostegoides, SEM images, AM W. 47634 (A – H, except B), AM W. 47635 (B). A. Peduncle and operculum; B. Close-up of operculum; C. Collar chaetae; D. Uncini of first thoracic chaetiger; E. Apomatus chaetae on chaetiger 3; F. Triangular chaetae of posterior abdomen; G. Overview of posterior abdominal chaetigers; H. Uncini of posterior abdomen. Photo: A – H—E. Kupriyanova & S. Lindsay. Scale bars: A – B = 100 µm, C – D, F, H = 2 µm, E, G = 10 µm.

FIGURE 22. A. Semivermilia pomatostegoides, close-up of operculum (left) (AM W. 28421), animal in tube (top right) (AM W. 47635) and empty tube (bottom right) (AM W. 28452); B. Semivermilis uchidai, specimen stained with methyl green, close-up of operculum (left) (AM W. 45052), animal in tube (top right) (AM W. 45052) and empty tube (bottom right) (AM W. 47635). Photos: E. Wong. Scale bars: A – B = 0.1 mm.