Peniagone vitrea Théel, 1882

Peniagone vitrea Théel, 1882 View in CoL

Peniagone vitrea Théel, 1882: 50–52 View in CoL , pl. 7: 7–9, 34: 17–18, 44: 10.— Hansen, 1975: 148–150, fig. 70.— Gebruk, 1990 (in Russian): 93–94, fig. 34: 4–9.— O’Loughlin, 1998: 504.— Bribiesca-Contreras et al, 2022: 74–75 View Cited Treatment , fig. 47. — Kremenetskaia et al. 2021: 13, fig. 8a–c.

Peniagone vitrea var. setosa Ludwig, 1893: 109 View in CoL ; 1894: 105–108. Peniagone setosa Ludwig. View in CoL — Clark, 1920: 136.

Material examined. NMV F308222 About NMV * (1) [IN 2022 V08 120] ; NMV F308226 About NMV (1) [IN 2022 V08 122] ; NMV F308268 About NMV (1) [IN 2022 V08 145] .

Diagnosis of IOT material. Large glassy-white to cream specimens up to 95 mm long, 20 mm wide and 20 mm high ( NMV F308222 preserved). Typical Peniagone shape, strongly raised anterior to mid-dorsally then flattening posteriorly, slightly convex to flattened ventrally. Broad and short anterior velum of four papillae, fused for most of their length, with two central papillae a little longer and freer. Mouth on distinct neck tube curved at an acute angle ventrally and with extended flaccid tentacles, only five remaining in the most complete specimen ( NMV F308222, fig. 7a). Tube feet also mostly stripped from these specimens but all free and restricted to posterior third. Skin feels very rough due to crowded ossicles that are visible to the eye. Typically, Peniagone - type crosses with short, smooth central beam, four straight to slightly curved spinous arms, and 2–4 straight, spinous apophyses (fig. 7g –i). Arms wide, apophyses more vertical and nearly as long as arms where complete. Velum ossicles similar. Tube feet ossicles variably similar tall crosses, to lower versions with wider arms and shorter apophyses. Tentacle ossicles mostly irregular smooth crosses without (or with very reduced) apophyses and straight to slightly or strongly curved rods, variably smooth, spinous, or branching (fig. 7d–f).

Remarks. Despite extensive damage the external morphology available is congruent with the type description for P. vitrea Théel, 1882 . Body wall ossicles also fit description, but some IOT ossicle arms were up to 417 μm long, much longer than the type ossicle arms noted as 160 μm. Tentacle ossicles for IOT included curved rods in addition to the straight rods and basic crosses mentioned for types.

Distribution. Widespread in Pacific Ocean, including Clarion-Clipperton Zone (CCZ), Kuril–Kamchatka Trench, off southern Chile, Gulf of Panama; off southern and eastern Australia; Antarctic; Indian Ocean (Australian IOT).

Full bathymetric range. ~ 1300–4990 m (IOT 3002–4990 m).

Type locality. off southern Chile, 2652 m .

This species previously recorded from Nowra to Point Hicks in AFD (January 2024), and from eastern coast of Australia (off southern Tasmania to northern NSW and Great Australian Bight off South Australia at depths of 1360– 4750 m) in ALA (January 2024). This IOT material represents a geographic range extension as the first record of the species from the Indian Ocean , and a potential bathymetric range extension with this previously reported as ~ 1300–4500 m in Kremenetskaia et al. (2021) .

References. AFD (2024), ALA (2024), Bribiesca-Contreras et al. (2022), Clark (1920), Hansen (1975), Kremenetskaia et al. (2021), Ludwig (1894), Théel (1882).