Atheraster arandae ( Mah 2006 ), 2022

Mah, Christopher L., 2022, New Genera, Species and Occurrences of Deep-Sea Asteroidea (Valvatacea, Forcipulatacea, Echinodermata) collected from the North Pacific Ocean by the CAPSTONE Expedition, Zootaxa 5164 (1), pp. 1-75 : 26

Atheraster arandae ( Mah 2006) nov. gen, nov. comb.

FIGURE 8C–E

Circeaster Mah 2006: 934

Diagnosis. Body stellate (R/r>4.0), small disk, arms narrow. Abactinal arm plates bare, transition between large arm plates and smaller disk plates abrupt. Marginal plates with prominent spine and abundance of smaller, secondary spinelets, especially on ventrolateral edge. Furrow spines 12–15, distinct adambulacral pedicellariae, paddleshaped. Adambulacral plate surface covered by 5–7 spinelets or rough-tipped granules.

Comments. The type locality and the earliest known collected specimens for this species were from the western Indian Ocean in the waters around Madagascar from 1600–2000 m depths with a subsequent specimen discovered from New Caledonia from 2160 m ( Mah 2006) .

This species was originally distinguished from Circeaster spp. by its elongate arms and by both series of marginal plates bearing prominent conical spines. As indicated below, it bears a strong resemblance with Atheraster symphonia n. sp. in sharing the presence of sharp spines on the superomarginal and inferomarginal plates. The individuals observed herein did not show granulation on the abactinal surface plates as they would on A. symphonia n. sp.

Individuals imaged during the CAPSTONE expedition are the first members of this species observed in situ and indicate a widespread occurrence for this species from the Indian Ocean to the North Pacific. Individuals from Salmon Bank in the Hawaiian Islands ( Fig. 8C, D ) and Rose Atoll in American Samoa ( Fig. 8E ) were observed feeding on isidid octocorals (commonly known as bamboo corals) in a manner typical of other goniasterid octocoral predators with the coral stalk engulfed within the ambulacral furrow and covered by tube feet and the extended pyloric stomach with absent polyps below the animal as it was climbing up the stalk.

Occurrence: Hawaiian Islands, American Samoa region, New Caledonia, Madagascar, 1600–2439 m.

Images Examined long armed morph. Salmon Bank , Hawaiian Islands, 26.81819568, -176.3150506, 1949 m. EX1504 L2_IMG_ 20150811 T222348 Z_ ROVHD _ASRAUD.jpg

short armed morph. Salmon Bank , Hawaiian Islands, 26.81694605, -176.315139, 2007 m. EX1504 L2_IMG_20150811 T205435 Z_ ROVHD _COR_ ASR _EATING.jpg (feeding on Isididae )

Karin Ridge , Hawaiian Islands, 16.143169, -167.8556648, 1967 m EX1504 L4_IMG_20150922 T200931 Z_ ROVHD _ ASR.jpg

Rose Atoll, American Samoa, -14.53758332, -168.080719, 2439 m. ( Fig. 8E ) EX1702 _IMG_20170218 T234059 Z_ ROVHD.jpg (feeding on Isididae )

Figures

FIGURE 8. In situ images. Heligmaster kanaloae n. gen. n. sp. A. Orange color morph. McCall Seamount, Hawaiian Islands. 2655 m. Imaged on vertical rock face. B. White color morph. South Midway Atoll region, 3917 m. Atheraster arandae C. Short armed morph. Salmon Bank, Hawaiian Islands. 2007 m. D. Long-armed morph. Salmon Bank, Hawaiian Islands, 1949 m. E. Rose Atoll, American Samoa, 2439 m. Atheraster sp. F. Bank Nine, Hawaiian Islands, 1635 m. G. Hawaiian Islands,