Paralophaster ferax Mah 2023, n. sp.

Paralophaster ferax n. sp. FIGURE 20A–F Etymology The species epithet ferax is Latin for fertile or fruitful, alluding to the brooding behavior found in this species. Diagnosis Body shape weakly stellate (R/r=1.7), arms short, triangular, disk large (Fig. 20A, C). Body thickened. Interradial arcs we...

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Bibliographic Details
Main Author: Mah, Christopher L.
Format: Other/Unknown Material
Language:unknown
Published: Zenodo 2023
Subjects:
Online Access:https://doi.org/10.5281/zenodo.8092155
http://treatment.plazi.org/id/03C387E8660CFFDCFF68E6A68794FAEE
Description
Summary:Paralophaster ferax n. sp. FIGURE 20A–F Etymology The species epithet ferax is Latin for fertile or fruitful, alluding to the brooding behavior found in this species. Diagnosis Body shape weakly stellate (R/r=1.7), arms short, triangular, disk large (Fig. 20A, C). Body thickened. Interradial arcs weakly curved. Largest R= 2.5 cm. Abactinal plates paxillate, each with spines, 10–25, each bearing pointed, jagged hyaline tips (Fig. 20B). Plates separated by membranous skin. Marginal plates 26–28 per interradius (13–14 per arm), widely spaced, single series of marginals observed, superomarginals not clearly discerned, these either weakly expressed or irregular. Marginal plates are large, paxillate with trunk-like shaft, head of paxilla with curved head, each bearing spines, 8–30 on plate surface. Actinal region small, with 1–4 small, round plates, each bearing 1–3 spinelets. Furrow spines, 2–4, palmate arrangement with basal webbing (Fig. 20F). Subambulacral spines two, decreasing to a single spine distally along arm, arranged transversely on adambulacral plate. Oral plates with 10 furrow spines, no suboral plates. No pedicellariae. Brooded juveniles in coelomic cavity (Fig. 20D, E). Comments This species displays closest resemblance to Paralophaster paucispinus n. sp. with which it shares a similarly low number of marginal plates, approximately 13–14 per arm, a single discernible marginal series with no clear superomarginal plates, similar numbers of furrow spines and a similar overall body shape. It differs in having significantly more abactinal spines, 10–25 versus 3–5 in P. paucispinus and in having abactinal paxillae with lobate rather than round bases in P. paucispinus . There are also more spines on the marginal paxillae, 8–30, than are on P. paucispinus , which only shows 4–10. Occurrence Scotia Sea, 3138–4429 m. Description Body weakly stellate (R/r=1.6–2.22), arms short, triangular in shape, disk large. Body strongly thickened. Interradial arcs weakly curved (Fig. 20A, C). Surface covered with membranous ...