Omphalopomopsis langerhansii ( Marenzeller, 1885 )

Bailey-Brock, Julie H. & Magalhães, Wagner F., 2012, A new species and record of Serpulidae (Annelida: Polychaeta) from Cross Seamount in the Hawaiian Chain, Zootaxa 3192, pp. 49-58 : 54

Omphalopomopsis langerhansii ( Marenzeller, 1885)

Figures 2 (C and D), 4 (A–M) and 5 (A–F)

Omphalopoma langerhansii Marenzeller, 1885: 219 –220, pl. IV, fig. 6.

Omphalopomopsis langerhansii— ten Hove & Kupriyanova, 2009: 69 , fig. 7a, b.

Material examined. Cross Seamount, Hawaii, “Moana Wave” cruise leg 13, dredge haul 2, 18 °47.52’N 158°13.73’W, HURL, 12/16/1981, 2,013 m (1, USNM 1156951; 1, BPBM R3558).

Description. TUBE: Tubes white, opaque, length 10–20 mm, width 2–3 mm; oldest part triangular in crosssection, with delicate flaring mouth, becoming round in section towards the mouth ( Figs. 2 C, 4A–C). Median keel of fine denticulate spines present ( Figs. 2 C, 4A, B) and projecting over the mouth; 2–3 rows of lateral spines, most numerous towards the mouth. Flared rims of earlier tube mouths evident as transverse raised flanges ( Fig. 4 C).

BRANCHIAE: Branchial crown with 10–12 radioles on either side, the second on the left side with operculum in both specimens.

PEDUNCLE: Opercular peduncle arises as the second filament on the left side and lies across the first and third normal radioles; oval and slightly flattened in cross-section.

OPERCULUM: Operculum with vesicular ampulla and a lightly calcified flat plate with slightly upturned rim and a convex center ( Figs. 2 D, 4D, E). Two small swellings (not wings) present where the ampulla joins the opercular stalk ( Figs. 4 D, E), the distal latero-dorsal “winglets” sensu ten Hove & Kupriyanova (2009: 22).

COLLAR and thoracic membranes: Collar trilobed. Thoracic membrane best developed anteriorly extending beyond last thoracic chaetiger; apron absent. Tonguelets not observed.

THORAX: Seven thoracic chaetigers, six uncinigerous. Uncinigerous rows of second chaetiger shorter and more widely spaced than subsequent chaetigers. Collar chaetae slender finely denticulate bayonet-like ( Figs. 4 F; 5A, B) and narrowly limbate capillaries with long blades ( Fig. 4 G). Chaetae of chaetigers 2–7 with simple blade. Apomatus chaetae observed from chaetiger 3 ( Fig. 4 H). Thoracic uncini saw-shaped with simple rounded anterior fang and 8–9 teeth ( Figs. 4 I, J; 5C). Uncini with 8 and 9 teeth in the same uncinigerous torus.

ABDOMEN: Abdominal chaetae of 2 types, anterior chaetigers with narrow flat geniculate chaetae ( Figs. 4 K; 5D) and posterior chaetigers with a few geniculate chaetae and long tapered capillaries with denticulate tip ( Figs. 4 L; 5E). Abdominal uncini rasp-shaped, smaller than thoracic ones, with 8–9 rows of teeth and a rounded anterior fang ( Figs. 4 M; 5F).

Remarks. One specimen with a large round, multilocular foraminiferan lodged in the intestine. Specimens fit well the generic description and illustrations by ten Hove & Kupriyanova (2009). These specimens appear to be a new and deeper record for Omphalopomopsis langerhansii , which is known from a single specimen collected from Enoshima in South Japan at 366 m (ten Hove and Kupriyanova, 2009).

Distribution. Enoshima, South Japan and newly recorded to Cross Seamount in the Hawaiian Chain; 2,013 m attached to small pieces of rock.

Figures

FIGURE 2. Metavermilia zibrowii sp. nov. A, Tube mouth with flared lip. B, lateral view of operculum showing concave opercular plate. Omphalopomopsis langerhansii C, entire tube. D, lateral view of operculum showing the concave opercular plate.

FIGURE 4. Omphalopomopsis langerhansii A, Tube. B, tube mouth with flaring lip; C, tube with transverse ridge from previous mouth; D, distal view of opercular plate; E, lateral view of operculum; F, collar chaeta; G, narrowly limbate thoracic capillary chaeta; H, Apomatus chaeta; I, J, thoracic uncini with 9 and 8 teeth respectively; K, abdominal flat geniculate chaeta; L, abdominal capillary chaeta with denticulate tip; M, abdominal uncinus. Scales: A, B and C— 2 mm; D and E— 1 mm; F— 0.05 mm; G— 0.1 mm; H— 0.05 mm; I and J— 0.04 mm; K— 0.06 mm; L— 0.05 mm; M— 0.02 mm.