Ahuastra gfoei ( Mah, 2022 ), 2024

Mah, Christopher L., 2024, New genera and species of deep-sea Goniasteridae (Asteroidea) from the North Pacific, Zootaxa 5543 (4), pp. 451-500 : 454-455

Ahuastra gfoei ( Mah, 2022)

FIGURE 1A–F

Litonotaster gfoei Mah 2022: 53 , Fig. 18A–F

Diagnosis

Body pentagonal (R/r=1.3). Abactinal plates irregular to polygonal in outline, with a bare central surface with irregularly shaped concavities surrounded by granules. Smaller plates and plates in the interradial regions are covered by granules. Papular pores, if present were not evident. Superomarginal and inferomarginal plates are identical in morphology and wider interradially. Superomarginals wide (W>L) with approximately 50% of surface (abactinal facing) bare in weakly circular pattern, lower half covered by coarse granules, 20–40 (mostly about 30). Inferomarginal plates with distinct cone-shaped spines present along actinolateral edge. Inferomarginal surface covered by coarse, round granules, 100–150, about 130–140 evenly distributed. Actinal plates covered by 3–20 short, pointed conical spinelets. Each plate irregular to polygonal in shape. Furrow spines four to six, tips blunt. Adambulacral plate surface with 7–20 short blunt spinelets similar to those on other actinal plate surfaces.

Comments

MCZ 162564 resembles the holotype of Litonotaster gfoei Mah 2022 in most respects, save for the observable papular regions showing the more distinct fasciolar channels around the paired plates on each arm base. Furrow spine number in MCZ 162564, n=7 to 9, was also higher than in the holotype, n=4 to 6. MCZ 162564, shows R =2.1, versus the holotype, R =1.1. Character differences between these two individuals appear most easily attributed to the larger size of MCZ 162564. However, the limited number of specimens makes it difficult to test other sources of variation for this species.

Occurrence

North Pacific. American Samoa, Rose Atoll, Moki seamount, Utu seamount, Malulu seamount, Se Guyot, Johnson Atoll region, Mozart seamount, Musicians Seamount region, 2010–3708 m.

Material Examined

MCZ 162564 North Pacific Ocean , 21.1883035 ° -162.6980645 ° 2183 m. Coll. E/V Nautilus 12 Dec. 2021, 1 wet spec. R=2.1 r= 1.4 cm .

Holotype. USNM 1453665 South Pacific, American Samoa. 14º26’S, 168º 38’W, 2457 m, Coll. NOAA Ship Okeanos Explorer w/ ROV Deep Discoverer EX 1702. 27 Feb 2017. 1 wet spec. R=1.1 r= 0.8 cm .

Figures

FIGURE 1. Ahuastra gfoei (Mah 2022) MCZ 162564. A. Abactinal. B. Closeup of radial papular region. C. Abactinal-lateral side showing superomarginal plates. D. Abactinal surface showing arm tip, superomarginal plates. E. Actinal. F. Closeup of adambulacral plates, including furrow and subambulacral spines. Scale bar=3.0 mm: A, E; Scale bar=2.0 mm: C, D; Scale bar=1.0 mm: B, F.

FIGURE 18. Evoplosoma anguirus n. sp. holotype. A. Holotype observed in situ on prey item (Isididae). B. Other side of specimen showing stomach extended. Distance between lasers = 10.0 cm.