Lygdamis augeneri Kirtley, 1994

Hutchings, Pat, Capa, María & Peart, Rachael, 2012, 3306, Zootaxa 3306, pp. 1-60 : 21-26

Lygdamis augeneri Kirtley, 1994

Figures 6B, 11A–D, 12–13, Table 2

Eupallasia giardi . — Augener, 1927: 236, fig. 14a–c; 1934: 92; not McIntosh, 1885.

Pallasia giardi . — Ehlers, 1920: 64; not McIntosh, 1885.

Lygdamis augeneri . — Kirtley, 1994: 119–120, figs 7.1.1–2.

Material examined. HOLOTYPE: As Eupallasia giardi Augener, 1927 (identified by Kirtley, 1994) off Disaster Bay, New South Wales: Australia: 37°05'S 150°05'E; 01.x.1914; 53–73 m; ZMH V-9569; Th. Mortensen's Endeavour, 20 mm in length (including damaged posterior end), 2 mm in width. PARATYPES: 3, from same sample as holotype.

Additional material examined. New South Wales: (Tasman Sea) off The Entrance , 33°14'12.6"S 156°10'40.8"E, 02.v. 1989, 133 m, 1, AM W27564*, 16 mm long, 1 mm wide, 24 segments; AM W27565 (mounted for SEM) .

Description. Holotype flesh coloured, no pigmentation present. Body elongate and slender ( Fig. 11A). Operculum with completely separated lobes, with distal end sloping; longer than wide ( Fig. 11A, B). Length of operculum more than one third the length of the body ( Fig. 11B, C). Paleae displayed in two rows, outer row with 42 pairs of paleae, with flattened shafts, smooth margins with tips curved outwards ( Fig. 13C); inner row with 30 pairs of paleae, cylindrical and tapering slowly to blunted tips ( Fig. 13C). Opercular papillae, 12 pairs, peripheral to outer row of paleae on each lobe, elongate, increasing in length towards nuchal spines ( Figs 12C, 13B), pair adjacent to nuchal spines about one quarter length of outer paleae. One pair of nuchal spines, strongly recurved, margins smooth, with pointed tips ( Figs 11A, 12D, 13B). Tentacular filaments compound arranged in 19 horizontal rows. Eye spots present along sides of median ridge. Pair of elongate grooved palps with crinkled margins on either side of median ridge, about one quarter length of opercular lobes. Segment 1 with lobe-shaped neuropodia ( Fig. 12B–E), capillaries absent. Segment 2 with three triangular lateral lobes on each side of body ( Fig. 12E), with fine capillaries arranged in compact fascicle, inserted in neuropodia, posterior to U-shaped buccal organ ( Fig. 12B). Eight pairs of dorsal branchiae present from segment 2, with narrow base and tapering gently to a fine tip, slightly ridged, size decreasing posteriorly, not meeting mid dorsally ( Fig. 11A). Segments 3–6 (parathoracic) with notochaetae arranged in two transverse rows, six long lanceolate, with tapering frayed tips, blades slightly concave and textured, and six capillaries inserted imbetween ( Fig. 13D). Segments 3–6 with two types of neurochaetae, six lanceolate, with frayed twisted tips, and compact thecae and fine capillaries with thin flattened blades with short narrow thecae, alternating with lanceolate ( Fig. 13E). Parathoracic notochaetae more robust than neurochaetae. Abdominal region with 19 chaetigers. Notopodia as transverse tori, with number of uncini decreasing posteriorly. Each uncinus with two vertical rows of eight teeth ( Fig. 13F). Neuropodia with capillaries arranged in discrete fascicle, with thin, flattened blades with short, narrow thecal rings. Cauda smooth, about length of last five chaetigers ( Fig. 11C).

Variation. Material examined, including sexually mature specimens, varies from 15–18 mm in length without cauda, 2–3 mm in width, with 19–23 chaetigers, 42–44 pairs of outer paleae, 30–36 pairs of inner paleae, 6–8 teeth on each row of uncini and 15–19 pairs of tentacular filaments. Pigmentation present along the rows of some tentacular filaments. We suggest that these variations are to some extent size dependent and pigmentation may be related to methods of preservation and subsequent storage.

Remarks. Kirtley (1994) described this species based on material examined by Augener (1927) who had identified it as L. giardi McIntosh, 1885 . The two species differ not only in the range of the number of pairs of outer paleae, 42–44 in L. augeneri and 16–20 in L. giardi , but also in the shape of the outer paleae. I. augeneri has outer paleae with curved flattened tips ( Fig. 13C) whereas those of L. giardi have asymmetrical flattened pointed tips ( Fig. 15C).

Distribution. South-eastern Australia.

Habitat. Shelf depths of 53–133 m.