Pseudopatiria O’Loughlin, 2004

O’Loughlin, P. Mark & Waters, Jonathan M., 2004, A molecular and morphological revision of genera of Asterinidae (Echinodermata: Asteroidea), Memoirs of Museum Victoria 61 (1), pp. 1-40 : 34

Pseudopatiria O’Loughlin gen. nov.

Figures 3d , 16g –i

Diagnosis. Rays 5; interradial margin deeply incurved, rays distinct, unequal in size, subcylindrical, narrowly flat actinally; margin weakly defined by irregular series of transversely elongate inferomarginal plates; abactinal plates irregular; abactinal spinelets opaque, digitiform to short columnar, dense subpaxilliform clusters; pedicellariae present in papular spaces; papulate areas extensive; papular spaces large, numerous secondary plates and small papulae; actinal interradial plates irregular in size and arrangement; actinal spines short columnar, dense subpaxilliform clusters; lacking superambulacral and superactinal plates; lacking interior contiguous projections of abactinal and actinal plates.

Type species. Patiria obtusa Gray, 1847 .

Material examined. P. obtusa . Holotype. Panama, 11–18 m, BMNH 1938.6.23.24 (dry; poor condition).

Description. Rays 5, subcylindrical, unequal in length, up to R = 54 mm; rays narrowly flat actinally, poorly defined margin; fasciculate pedicellariae between abactinal plates, 2–3 curved digitiform valves; not fissiparous.

Abactinal surface uneven, with abactinal plates domed and irregular in size and arrangement on upper rays, in angled series on sides of rays; papulate areas extensive, to near margin; papular spaces large, numerous large secondary plates intergrading with primary plates, numerous papulae; single large madreporite; disc not bordered by regular series of radial and interradial plates; abactinal plates crescentiform or elongate or rounded, with high dome, lacking glassy convexities; spinelets thick, digitiform to short columnar, distally minutely spinous, typically 0.4 mm long, in close subpaxilliform clusters of about 40 spinelets per plate; superomarginal and inferomarginal plates in irregular series, inferomarginals frequently transversely elongate, projecting slightly to define margin.

Actinal interradial plates irregular in size and arrangement.

Actinal spines per plate: oral 6, some thick subspatulate; suboral, cluster, some thick subspatulate; furrow 3, subspatulate; subambulacral and actinal dense clusters of up to 20 per plate; spines short columnar, typically 0.5 mm long.

Superambulacral, transactinal and superactinal plates absent; margin not supported by contiguous internal projections of abactinal and actinal plates; internal resinous body lining.

Distribution. Panama; 11– 18 m.

Etymology. From the Latin pseudo (false), with Patiria , referring to the significant internal skeletal differences with the genus Patiria .

Remarks. Gray (1866) and Verrill (1870) retained obtusa in Patiria , but Perrier (1875) referred the species to Asterina . Verrill (1913) referred it to Callopatiria . A.M. Clark (1983 figs 5a, 7) also discussed the generic placement and noted the absence of what are referred to in this work as superambulacral and superactinal plates. A.M. Clark (1993) noted the need for a reassessment of generic status and opined that the single specimen was “probably from the Pacific side of Panama ”. No molecular data are available, and a morphological reassessment is undertaken here. The unique characters of this asterinid genus are: subcylindrical rays; irregular abactinal and actinal plate arrangements; plates with subpaxilliform dense clusters of opaque, thick, short columnar spinelets and spines; presence of pedicellariae; and absence of superambulacral, transactinal and superactinal plates.

Figures

Figure 3. Abactinal views of type species of Asterinidae genera (continued; Tremaster mirabilis is figure 17e). a, Patiria miniata (R = 67 mm, NMV F98040). b, Patiriella regularis (R = 31 mm, AM J5594). c, Pseudonepanthia gotoi (R = 74 mm, holotype, USNM 36899). d, Pseudopatiria obtusa (R = 54 mm, holotype, BMNH 1938.6.23.24). e, Stegnaster inflatus (R = 45 mm, NMV F95675). f, Tegulaster emburyi (R = 19 mm, holotype, AM J5605).

Figure 16. a–d, Parvulastra exigua: a, cleared ray (R = 10 mm, NMV F98062); b, denuded abactinal granuliform spinelets (NMV F98062); c, actinal interradius (R = 9 mm, NMV F98062); d, oral spines (R = 10 mm, NMV F97450). e–f, Patiriella oliveri (R = 28 mm, MNZ EC4805): e, abactinal disc and spinelets; f, absence of superambulacral plates (left arrow), presence of superactinal plates (right arrow). g–i, Pseudopatiria obtusa (R = 54 mm, holotype, BMNH 1938.6.23.24): g, section of ray with absence of both superambulacral and superactinal plates; h, abactinal subpaxilliform spinelets, and pedicellaria (lower left); i, actinal spines.