Ahuastra kupanaha, Mah, 2024

Mah, Christopher L., 2024, New genera and species of deep-sea Goniasteridae (Asteroidea) from the North Pacific, Zootaxa 5543 (4), pp. 451-500 : 455-457

publication ID	https://doi.org/ 10.11646/zootaxa.5543.4.1
publication LSID	lsid:zoobank.org:pub:E34AF3EF-4D03-4C08-8E11-C9514D42021B
persistent identifier	https://treatment.plazi.org/id/03C83A1C-FF99-C347-FF77-2DBE565F47E4
treatment provided by	Plazi
scientific name	Ahuastra kupanaha
status	n. gen.

Treatment

Ahuastra kupanaha n. gen. n. sp.

FIGURE 2A–E View FIGURE 2 , 12A View FIGURE 12

Etymology

The specific epithet is the Hawaiian word for “wonderful”, taken in apposition. The species name thus refers to “Wonderful Mound Star.”

Diagnosis

Body soft, weakly stellate to stellate (R/r=1.5–2.6), disk thick, almost dome-like in shape, strongly convex proximally with short arms, triangular in cross-section and weakly curved to straight interradial arcs. Abactinal plates composed of two discrete regions, a radial, papular region with large, pentagonal to polygonal plates, approximately 2X to 3X the size of the adjacent and non-radial plates and well-developed fasciolar grooves. The second, remaining abactinal plates round to polygonal, smaller than those on papular regions. All plates covered by granules, becoming most abundant and densely arranged interradially. Superomarginal plates present on abactinal side, approximately 24–25 per interradius (arm tip to arm tip), inferomarginal plates forming actinolateral ledge below superomarginal plates. Actinal surface flat, interradial region covered by widely spaced short spinelets and pedicellariae, 2–6 per interradius. Furrow spines 9-10, subambulacrals 7-10, spread out on adambulacral plates surface.

Comments

Ahuastra kupanaha n. gen. n. sp. appears morphologically distinct from Ahuastra gfoei , in that it shows a more stellate body shape, a more strongly arched disk, sharply tapering arms as well as abactinal plates covered by granules versus the latter A. gfoei showing a pentagonal body, relatively flat body with confluent arms, and an abactinal surface with bare plate center but with distinctly peripheral granules around each plate. Additional shared characters include the distinct bare patch on the superomarginal plate surface, inferomarginal plates which form an extended ledge out from the superomarginal plates as well as the distinct bare space on the adambulacral plates adjacent to the furrow spines.

Occurrence

North Pacific, 3257–3627 m.

Description

Body weakly stellate to stellate ( R /r=1.7–2.6), disk thick, almost dome-like in shape ( Fig. 2A View FIGURE 2 , 12A View FIGURE 12 ), strongly convex proximally with short arms, triangular in cross-section and weakly curved to straight interradial arcs ( Fig. 2A View FIGURE 2 ).

Abactinal surface composed of two discrete areas, five radial regions with distinct hexagonal shaped plates covered by two types of widely spaced granule types and well-developed fasciolar channels ( Fig. 2B, C View FIGURE 2 ). These radial regions have approximately 12–25 round granules on the central plate region with trapezoid-shaped granules, 20–30 forming periphery around them. Granules on these discrete radial areas becomes more identical with those elsewhere on the disk at the contact between them. Single papulae present at the corners of each plate on these distinct radial areas ( Fig. 2C View FIGURE 2 ). Secondarily, abactinal plates on remainder of abactinal surface composed of closely arranged round to irregularly polygonal plates, covered by a dense coat of round granules. Granules in these areas are abundant, densely arranged, and include approximately 5 granules along a 1.0 mm line count. Granules become very dense interradially, especially adjacent to contact with superomarginal contact ( Fig. 2B View FIGURE 2 ). When observed in situ, these plates and granules are such more widely spread from one another appearing like discrete round granular mounds ( Fig. 12A View FIGURE 12 ). Fasciolar grooves, if present, concealed by close-set plates and granules. Granules in some areas have been removed and on some proximal plates, are lost, leaving shallow convexities on the plate surface. Where granules are entirely absent from plates, surface weakly convex to flat. Madreporite irregular in outline, flat but appressed against a strongly convex plate. Anus centrally present, flanked by four ovoid to irregularly round plates, each covered by easily abraded granules. MCZ 162844 did not show pedicellariae in contrast to MCZ 162556 which showed several on the abactinal surface.

Superomarginal and inferomarginal plates 24–25 per interradius (arm tip to arm tip). Marginal plates offset, forming zig-zag contact between them throughout. Superomarginal plates quadrate in shape, wide but present entirely on the abactinal surface ( Fig. 2B View FIGURE 2 ). Inferomarginal plates also wide with upper surface approximately 50% present on abactinal surface, forming the actinolateral edge around the periphery. Superomarginal plates with distinct, weakly quadrate bald patch on surface. Other than this region, granules, 20–70 round with pointed tips cover peripheral surface of all superomarginal plates, sometimes forming two to three indistinct series. Distally, granules attenuate to only one or two series around plate periphery with bald area increasing in size adjacent to terminal plate. Inferomarginal surface completely covered by pointed but easily abraded granules, 20–200, evenly covering surface of plate. Single paddle-like pedicellariae present on plate surface near actinolateral surface. Actinolateral surface distinct, forming a distinct edge. Spinelets around upper surface inferomarginal plates pointed, forming a spine-like series along edge. Spinelets, modified from granules present, evenly spaced on actinal surface of inferomarginal plates. Single small 1.0 mm paddle-like pedicellariae on actinal surface of inferomarginal plate. Terminal plate diamond shaped, smooth surface.

Actinal surface smooth, flat, with quadrate to irregular shaped plates in chevron formation, plate boundaries shallow. Spinelets, short, triangular shaped, pointed, 2–15, mostly 4–8, present on each plate, widely spaced along surface ( Fig. 2E View FIGURE 2 ). Prominent pedicellariae, 2–6, paddle-shaped varying in size from 1–3.0 mm in length on proximal plates in each actinal interradius, especially adjacent to adambulacral plate series ( Fig. 2E View FIGURE 2 ).

Furrow spines 9–10, mostly 10, short, blunt-tipped in straight to weakly curved series ( Fig. 2E View FIGURE 2 ). Distinct space present on adambulacral plate surface. This surface with a distinct paddle-shaped pedicellariae (1–2.0 mm) on a single plate per arm, which is otherwise bare. A series of approximately 7 to 10 short spinelets, widely spaced, on adambulacral plate periphery on the actinal intermediate side. Oral plates with 20 furrow spines along each edge, with large two blunt spines projecting into the mouth. Oral plate surface covered by approximately 30–40 triangular spines identical to those on the actinal intermediate surface. Although paired spinelets, 6–8 and a bare space is present where the fossae created by the paired oral plates is located, there is region seems obscured by tissue.

Living color is beige-white with a darker beige present on the radial regions ( Fig. 12A View FIGURE 12 ).

Material Examined

Holotype. MCZ 162844 East of Midway Atoll, North Pacific Ocean , 28.5396175 ° -171.0747741 °, 3257 m. Coll. R/V Nautilus, ROV Hercules , April 23, 2022. 1 wet spec. R=2.9 r= 1.7 cm GoogleMaps .

Paratype MCZ 162556 West of the Hawaiian Islands, North Pacific Ocean , 21.22359125 ° -162.7125112 °, 3627 m. Coll. R/V Nautilus, ROV Hercules with slurp gun. Dec. 11, 2021. 1 wet spec. R=5.6 r= 2.1 cm .