Astrotholus mei Mah 2023, n. gen.
Astrotholus mei n. gen. n. sp. FIGURE 3A–F Etymology This species is named in the memory of Mei Elizabeth Sato (2006–2021), daughter of colleague Anouchka Krygelmans, formerly of the Muséum national d’Histoire naturelle . Species name, noun held in apposition. Diagnosis Body weakly stellate, with si...
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| Format: | Other/Unknown Material |
| Language: | unknown |
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Zenodo
2023
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| Online Access: | https://doi.org/10.5281/zenodo.8090100 http://treatment.plazi.org/id/03C387E8663FFFF3FF68E6EE85B6FAC2 |
| Summary: | Astrotholus mei n. gen. n. sp. FIGURE 3A–F Etymology This species is named in the memory of Mei Elizabeth Sato (2006–2021), daughter of colleague Anouchka Krygelmans, formerly of the Muséum national d’Histoire naturelle . Species name, noun held in apposition. Diagnosis Body weakly stellate, with size up to R= 2.4. Spines, 6 to 30, clavate on subpaxillate abactinal plates (Fig. 3A). Superomarginals and inferomarginals similar in size (Fig. 3E). Actinal spines elongate, one to two per plate, mostly one. Furrow spines 2 to 5, proximally 3 to 4 webbed with a distinct transverse series of webbed subambulacral spines, 2 to 3 set off from the furrow by a distinct space (Fig. 3F). Comments Of the Astrotholus spp. Astrotholus mei n. gen. n. sp. displayed the largest and most robust individuals with largest size at R= 2.4 cm demonstrating a correspondingly thick disk. Despite its massive appearance and differing number and shape of its actinal spines this species shares several character similarities with Astrotholus antarcticus , in displaying more granuliform spinelets and mound-like abactinal plates. Occurrence Scotia Sea, off South Georgia Island, −55.092, −39.842, 2886–3040 m. Description Body weakly stellate (R/r=1.4–2.0 at R=0.8, but mostly 1.4–1.5), disk thick, strongly arched, actinal surface concave, interradial arcs weakly curved to straight (Fig. 3A). Body surface with a distinct dermal layer underlying spaces between plates. Abactinal plates imbricate, subpaxillate, each plate topped by densely arranged short, club-tipped spinelets with very minute micro-spinelets (barely visible without a microscope). Spinelets, six to 50 at R=2.3 (Fig. 3B). Spinelet count appears size dependent with smaller plates having fewest number; largest plates with greatest spinelet number. Individually plates are irregular to polygonal in outline, with a pronounced central mound becoming simpler and more found distally adjacent to superomarginals. Radial plates along arm, two to four, each with low, irregular mound-like shape ... |
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