Laetmonice hutchingsae, Flaxman & Kupriyanova, 2024

Flaxman, Beth & Kupriyanova, Elena K., 2024, New species of Laetmonice (Aphroditidae, Annelida) from bathyal and abyssal depths around Australia, Records of the Australian Museum 76 (4), pp. 195-210 : 200-202

publication ID	https://doi.org/10.3853/j.2201-4349.76.2024.1900
persistent identifier	https://treatment.plazi.org/id/F44D8796-660C-E131-B3E8-52741C26D8B0
treatment provided by	Felipe
scientific name	Laetmonice hutchingsae
status	sp. nov.

Treatment

Laetmonice hutchingsae View in CoL sp. nov.

urn:lsid:zoobank.org:act:CCF42BF8-4722-4472-892C-6902B9B87EB1

Figs. 3a View Figure 3 , 4a View Figure 4

Material examined. Holotype: AM W.53946, Jervis CMR, 2650 m, 29 May 2017 . Paratypes: AM W.53947, Jervis CMR, 2650 m, 29 May 2017 ; AM W.53945, Jervis CMR, 2650 m, 29 May 2017 . Additional material is listed in Appendix 1.

Description. Holotype ( Fig. 3a View Figure 3 ), with 34 segments, length 46 mm, maximum width 25 mm (including chaetae) and 19 mm (excluding chaetae). Body ovate to elongate, dorsoventrally flattened, dorsal felt absent. Ventral surface cream-coloured, covered with fine papillae.

Prostomium rounded, with a large pair of anterolateral cylindrical ocular peduncles equivalent in length to prostomium, with a gap between them, eyes absent. Ceratophore of median antenna large (approximately length of prostomium) located posteriorly to ocular peduncles ( Fig. 4a View Figure 4 ); style slender with a bulbous tip, four times as long as prostomium (absent from holotype, observed from NMV F 313504 About NMV ). Palps finely papillated, extending to segment 15. Nuchal flaps absent. Facial tubercle located below ocular peduncles with long papillae .

Elytra 15 pairs, attached to elytrophores on segments 2, 4, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 28 and 31, completely covering dorsum; elytra rounded, white in colour and densely covered in brown spotted pigmentation, without tubercles or papillae on surface and margins. Dorsal cirri present on segments without elytra; cirrophores short and cylindrical, styles with bulbous tips, three to four times length of parapodia.

First segment with elongated uniramous parapodia, inserted anterolaterally to prostomium; three tufts of fine, golden acicular chaetae, extending from dorsal, ventral and anterior margins of parapodia. Each with a pair of long dorsal and ventral tentacular cirri, extending laterally with bulbous tips.

Following segments with biramous parapodia. Segments 2–4 notopodia with pointed aciculum and fans of fine acicular chaetae. Neuropodium conical, with two tiers of neurochaetae; lower tier with numerous golden bipinnate neurochaetae, upper tier with 1–2 neurochaetae, with basal spur and distal fringe of hairs. Neuropodia from segment 5 to posterior end elongated, cylindrical with inflated base; three to four golden yellow neurochaetae with basal spur and distal fringe of hairs. Ventral cirri long, reaching distal tip of neuropodia on anterior four segments, attached on ventral base of neuropodia on segment 2, posteriorly gradually shifting to middle position of ventral surface of neuropodia.

Elytrigerous notopodia with tuft of up to 14 golden acicular notochaetae, tapering with pointed tip, projecting from triangular acicular lobe. Posterior to acicular notochaetae, between four and nine dark brown harpoon notochaetae (observed from AM W.54324), tuberculated with three to five recurved fangs and approximately double body width in length.

Cirrigerous notopodia with supra-acicular lobe on dorsal margin and three to four tufts of notochaetae; short, fine capillary chaetae extending from supra-acicular lobe; long, fine, pale acicular chaetae on anterior and ventral margins; stiff, golden acicular chaetae on posterior margin. Anterior margin of acicular lobe curved, cirrophore and aciculum located on posterior margin, oriented posterior-laterally.

Variation. Body length 13–46 mm, number of segments 32–34, and number of elytra pairs 14–16. Brown speckled pigmentation on elytra varies in density from faint to dense. Larger specimens with longer ventral cirri on segments 2–4, reaching distal tip of neuropodia.

Diagnosis. As for the genus; with a combination of 28–34 segments, 14–15 elytra pairs, ocular peduncles large, half the length of the prostomium, median antenna located posterior to ocular peduncles, palps extending to segment 15, 4–9 harpoon chaetae per notopodium, with tuberculate shafts and three to five recurved fangs. Most similar to Laetmonice yarramba .

Etymology. This species is named after Dr Pat Hutchings (Australian Museum) for her remarkable dedication and invaluable contributions to taxonomy of polychaetes in Australia and world-wide.

Distribution. The Great Australian Bight and the Eastern Australian Abyss from off Tasmania (41° S) up to Fraser Island (25° S). Seamounts of the Indian Ocean Territories. Clarion-Clipperton Zone, Pacific Ocean. Bathyal-abyssal (1010–3096 m).