Litonotaster intermedius ( Perrier, 1894 )

Litonotaster intermedius ( Perrier, 1894) View in CoL .

Figures 12A–E

Pentagonaster intermedius Perrier, 1884: 243 View in CoL , pl. 5, figs. 5–6 (Non- Pentagonaster intermedius Alcock, 1893: 90 View in CoL )

Litonotaster intermedius Verrill, 1899: 172 View in CoL , pl. 28, figs 5–5b, H.L. Clark, 1941: 48; Madsen, 1951: 88; Halpern, 1969: 130, figs. 1B,2,3; 1970: 147; Clark and Downey, 1992: 250, pl. 59C, D.

Litonotaster rotundigranulum Halpern, 1969: 134 View in CoL , figs. 6–7; 1970: 252 figs 20–22, 1970b: 153, fig. 6.

Material Examined. NMV F240390 About NMV . Great Australian Bight 35º 09' 10" S, 134º 06' 32" E to 3º 10' 56" S, 134º 06' 32" E. 965–1077 m. Coll. IN2015_C02, GAB BP. 15 wet specs. R = 2.2 r = 1.0; R = 2.6 r = 1.3; R = 2.2 r = 1.1; R = 2.0 r = 1.1; R = 3.1 r = 1.6; R = 3.2 r = 1.7; R = 2.9 r = 1.5; R = 3.4 r = 1.9; R = 3.0 r = 1.5; R = 3.6 r = 2.0; R = 4.4 r = 2.3; R = 3.9 r = 2.2; R = 4.1 r = 2.2; R = 4.3 r = 2.3; R = 4.5 r = 2.4; R = 5.0 r = 2.6.

WAM Z110120 About WAM . Gascoyne Marine Reserve , 21º 2'15.99" S, 112º 38' 30.2316" E, 1534 m. Coll. Alvarez, B., Naughton, K.M., Moore, K., Unteidt, C. GoogleMaps CSIRO Gascoyne 10052793, 27 Nov 2022. 1 wet spec . R = 5.4 r = 2.3.

WAM Z110036 About WAM . Gascoyne Marine Reserve , 20º48'8.1612"S 111º36''55.5984" E, 2013 m. Coll. Alvarez, B., Naughton, K.M., Moore, K., Unteidt, C. CSIRO Gascoyne 10051556, 3 December 2022. 1 wet spec . R=3.8 r=2.0.

WAM Z110042 About WAM . Gascoyne Marine Reserve , 20º 49' 41.3616" S, 111º36'12.2256" E, 2057 m. Coll. Alvarez, B., Naughton, K.M., Moore, K., Unteidt, C. GoogleMaps CSIRO Gascoyne 10051697, 4 Dec. 2022. 2 wet specs . R = 5.2 r = 2.3 R = 4.8 r = 2.4.

WAM Z110121 About WAM . Gascoyne Marine Reserve , 21º 2' 15.99" S, 112º 38' 30.2316" E, 1534 m. Coll. Alvarez, B., Naughton, K.M., Moore, K., Unteidt, C. GoogleMaps CSIRO Gascoyne 10052794, 27 Nov. 2022 .

2 wet specs. R = 2.0 r = 1.1 R = 0.9 r = 0.6

WAM Z 110170.123 km WSW Ningaloo Reef. Western Australia, 22º59'12.282"S 112º28'42.3408" E, 1451 m. Coll. Alvarez, B., Naughton, K.M., Moore, K., Unteidt, C. GoogleMaps CSIRO Gascoyne 10055923, 9 Dec. 2022. 4 wet specs . R = 2.4 r = 1.3, RE = 3.0 r = 1.6, R = 4.2 r = 3.1, R = 4.7 r = 2.4.

WAM Z110050 About WAM . Gascoyne Marine Reserve , 20º 48' 12.0672" S 111º 43' 39.2088" E, 1558 m. Coll. Alvarez, B., Naughton, K.M., Moore, K., Unteidt, C. GoogleMaps CSIRO Gascoyne 10055923, 4 December 2022 .

8 wet specs. R = 1.1 r = 0.6, R = 2.1 r = 1.1, R = 1.9 r = 1.0 R = 2.8 r = 1.4 R = 2.8 r = 1.5, R = 1.5 R = 1.3 r = 0.7 R = 3.4 r = 1.5 R = 4.0 r = 1.9.

WAM Z110097 About WAM . Gascoyne Marine Reserve , 22º 22' 28.0236" S, 113º 13' 28.9272" E, 1497 m. Coll. Alvarez, B., Naughton, K.M., Moore, K., Unteidt, C. GoogleMaps CSIRO Gascoyne 10055923, 25 November 2022. 1 wet spec . R = 5.3 r = 2.3.

Diagnosis (Based on Clark and Downey, 1992). Body stout, shape weakly stellate to stellate (R/r = 1.3–2.3), arms short, triangular. Interradial angles weakly curved to straight. Abactinal plates abutted, polygonal to quadrate, surface completely covered by round, granules, 7 to 24, variably with small central areas bare. Marginal plates 20–24, surface bare but with dense granulation around periphery and on inferomarginal surface completely covered by granules, completely covered by coarse, round granules, approximately 80–150, widely spaced. Furrow spines 3 to 8, mostly 5 to 7 in straight series. A single clamp-like pedicellariae present proximally on the adambulacral plate, remainder of plate covered by subambulacral granules in 3 loosely linear series, evenly spaced.

Comments. Characters observed on specimens from Australian waters were consistent with those observed from the Atlantic, varying in minor respects with regard to furrow spine number and granular cover, which have already recorded as being variable among Atlantic specimens. L. intermedius appears to be a primarily deep-sea goniasterid species, such as S. nieseni , which shows widespread distribution across its range.

Occurrence/Distribution. Atlantic Ocean. Gulf of Mexico, Cuba, Straits of Florida, West Indies, 1060–3530 m.

Pacific Ocean. Great Australian Bight, 965–1077 m.

Indian Ocean. Gascoyne Marine Reserve, 1451–2057 m.

Description. Body stout, shape weakly stellate to stellate (R/r = 1.3–2.3), arms short, triangular. Interradial angles weakly curved to straight ( Fig. 12A).

Abactinal plates abutted, variably polygonal to quadrate with larger plates centrally becoming smaller and more irregularly shaped distally, adjacent to superomarginal contact. Plate periphery surrounded by prominent ring of quadrate granules, 7 to 24, mostly 10–15 occupying approximately 20–25% of total plate diameter. Peripheral granules directly abutted against peripheral granules of adjacent plates forming a thick boundary between them ( Fig. 12B). Further granules present on plate surface contributing up to twice or even three times a granular ring around each plate. Most central plate surfaces flat to weakly convex, bare, especially those interradially, but variably, several plates on radial regions with 4 to 10 identical close-set granules present on central region presenting a densely granular appearance when present ( Fig. 12B–C). These dense granular regions are especially prominent at contact between abactinal and superomarginal plates. Pedicellariae small, paddle-like similar in size to granules on plates, present on a minority of plates, perhaps 20–30% of total irregularly distributed over abactinal surface. Papulae single, present with greatest abundance on radial regions along arms, absent interradially. Madreporite approximately 3.0 mm in length, quadrate to irregularly round, flanked by abactinal plates, 4 to 8 partially obscured by 7–10 coarse granules. Sulci well developed.

Marginal plates approximately 10–12 plates per arm side, 20–24 per interradius (arm tip to arm tip at R=5.2). Distalmost two to three pairs of superomarginals abutted along midline ( Fig. 12A, C). Superomarginal plates elongate becoming squarish distally along arms. Abactinal-lateral angle rounded. Inferomarginal plates larger than superomarginals especially interradially with quadrate/square shape to arm tip. Superomarginal and inferomarginal plates slightly offset forming zigzag contact between them. Superomarginal plate surface irregularly bare on abactinal surface, lateral surface covered by 10–30 coarse, round granules, widely spaced, irregularly arranged, present in 2 to 3 series covering lateral surface. Peripheral granules quadrate, approximately 10–30 per side. Inferomarginal plate surface completely covered by coarse, round granules, approximately 80–150, widely spaced. Inferomarginal plates with quadrate angles, straight line contact with superomarginal and actinal plate fields. Penultimate superomarginals compressed in size, with bare surface, terminal plate triangular with smooth surface.

Actinal plates with three complete series and incomplete irregular series adjacent to the inferomarginal plate contact ( Fig. 12D–E). Plates continue from disk, attenuating to a single series approximately midway along arm. Actinal plate surface with 20–120 coarse, round granules present, widely and evenly spaced. Peripheral granules, approximately 20–50, mostly 30–40 similar to the central surface.

Furrow spines 3 to 8, mostly 5 to 7 in straight series, with decreasing number distally ( Fig. 12E). Spines short, quadrate in section with blunt tips. A single clamp-like pedicellariae present proximally on the adambulacral plate, remainder of plate covered by subambulacral granules in 3 loosely linear series, widely but evenly spaced.

Oral plate furrow spines 10, forming linear series with furrow spines, quadrate in cross-section with blunt angular tips ( Fig. 12D, E). Remainder of oral plate surface with approximately 10 angular. Flat granules present along either side of interradial diastema on oral plate. Remainder of oral plate surface covered by 10–20 angular granules similar to those on subambulacral surface of other plates.