Paelopatides sp.

Paelopatides sp. MoV. 7336

Material examined. NMV F308191 About NMV * (1) [IN 2022 V08 115] ; NMV F308306 About NMV * (1), [IN 2022 V08 181] .

Diagnosis of IOT material. Large oval, light to dark purple, thick, firm, depressed specimens, up to 33 cm long and 16 cm wide ( NMV F308191, pre-preservation). Dorsal surface low convex, with delineation between central body and brim not clear, but possibly more visible here in NMV F308306 (fig. 47c, d). Scale pattern sometimes visible dorsally. Central section between the dorsal radii is lighter in colour and thick with central ridges and protuberances, which are absent from the smooth skin of the brim between the dorsal radii and the lateral edge. Up to four single scattered rows of retracted papillae dorsally, visible when off centre, any additional papillae obscured mid-body by the wrinkled ridges and raised knobs with dark purple patches mid-body, though occasional papillae projecting from domed bases here. Lateral edge also with raised protuberances and/or ridges and canals indicating likely retracted papillae, though not seen here. Ventral surface also low convex with no clear delineation between sole and brim, other than the midventral being a clear lighter colour with darker midventral furrow and many horizontal dark purple wrinkles and ridges.Two alternating rows of midventral tube feet evident in posterior section only. Anus dorsal. Mouth ventral. Thick tentacles retracted (~15 visible), each with four or more knobbed orange/brown lateral digits. Specimens are still firm and rigid but shrink on preservation to 23 cm long, 11 cm wide, and 3.5 cm high ( NMV F308191), and 20.5 cm long, 11 cm wide, 2 cm high when preserved ( NMV F308306, from ~ 24 cm long, 14 cm wide). A thick main lateral brim and two thinner posterior-lateral brims of fused papillae are also clearer on preserved specimens. Colour is almost black dorsally but purple ventrally. Body wall with triradiate ossicles present, often with long arms and central spire and minimal branching on all.

Remarks. Based on ventral tube feet being restricted to the rear third of the body, these specimens key to Paelopatides illicitus Sluiter, 1901 using the available key to southern hemisphere Paelopatides ( Martinez et al., 2019) , but IOT specimens are much smaller, not cylindrical, and ossicles are not a match to type illustrations (Sluiter, 1901). Not a clear match to any species described and illustrated in Koehler and Vaney (1905), for example wider and with more dorsal papillae than P. insignis , closer shape to P. ovalis but with less defined brim, fewer midventral tube feet, and dorsal papillae restricted to dorsal radii, completely different shape to the elongated P. gelatinosus (also imaged in Wirawati and Setyastuti, 2021), has the wart-like dorsal surface of P. verrucosus , but again not a match to the body shape. Not a match to the triradiate or rod ossicles of species illustrated in Koehler and Vaney (1905): P. verrucosus , P. ovalis , P. insignis , P. modestus , P. magna . Ossicles are possibly closest to P. incerta , being triradiate with long straight arms and minimal branching at ends, but the specimens lack the clear brim and non-retractile papillae of that species. We identify our specimens here as Paelopatides sp. MoV. 7336, noting that additional genetic samples, literature review, and morphological examination of comparative material may be required before confirming whether this is a new or existing species.

References. Koehler and Vaney (1905), Martinez et al. (2019), SolÍs-MarÍn (2003), Wirawati and Setyastuti (2021).