Pauliastra enigma Ludwig, 1905

Mah, Christopher L., 2021, The East Pacific / South Pacific Boundary: New taxa and occurrences from Rapa Nui (Easter Island), New Caledonia and adjacent regions, Zootaxa 4980 (3), pp. 401-450 : 413-414

Pauliastra enigma Ludwig, 1905 n. comb.

Figure 4C–D

Ludwig 1905: 151; Ziesenhenne 1937: 215; Maluf 1988: 119; Hendler 1996: 320 (as Pauliella ).

Validity of Pauliastra . There has been historical disagreement over whether this taxon should be considered as a synonym of Paulia Gray, 1840 . Döderlein (1936) argued it was a juvenile of Paulia . Rowe (1977) doubted this conclusion and Hendler (1996) treated Pauliella as a distinct genus citing what appeared to be adult specimens, presumably based on size. USNM material of this species (USNM 1020006) was further compared with other asterodiscidids and is consistent with the latter conclusion that Pauliastra is a separate, valid genus.

Further examination indicates that neither Amphiaster insignis nor Paulia horrida were morphologically consistent with the Pauliastra specimen examined. Comparison with small-sized Amphiaster (CASIZ 108856 at R=1.0 cm) shows that they are distinctly different, displaying a more stellate body and prominent conical spines as observed in adult specimens, ruling out small sized Amphiaster insignis as a possible adult for Pauliastra . Although comparably sized specimens of Paulia horrida were not available, large sized specimens of this species (USNM E18919 , R=6.3) do not display the distinct shallow fascicles, the distinct, round abactinal plate morphology nor the distinct dorsal-facing superomarginal plate series with strongly arching convex surface.

As indicated elsewhere a small sized individual of Asterodiscides has been shown to be very similar in appearance to Pauliastra aenigma suggesting the possibility that P. aenigma could be a small sized individual of an as yet undescribed species of Asterodiscides . As indicated under Asterodiscides truncatus that specimen displays several character differences from Pauliastra which are consistent with other differently sized individuals for that species suggesting close relationship but not synonymy.

Occurrence. Cocos Island , Costa Rica; Clarion Island, Rocas Alijos, 57.9–95 m.

Material Examined. USNM 1020006 . Cocos Island , Costa Rica, North Pacific, 5º32′N, 87º00′W, 91–95 m. Coll. John Pearse, R / V Te Vega, 22 Oct. 1968. 1 dry spec. R =1.9, r=1.2 .

Figures

FIGURE 4. Asterodiscides small specimens. MNHN IE-2007-6499 (New Caledonia): A. Abactinal. Scale bar equals 0.5 cm. B. Actinal surface. Scale bar equals 0.5 cm. MNHN IE-2013-7014 (New Caledonia). E. Abactinal. Scale bar equals 0.1 cm. F. Actinal surface. Scale bar equals 0.1 cm. Inset shows lateral view of specimen. Total length = 4.0 mm. Pauliastra sp. USNM 1020006 (Costa Rica): C. Abactinal. D. Actinal surface. Scale bar equals 0.5 cm.