Poraniopsis echinaster Perrier 1891

Poraniopsis echinaster Perrier 1891

Poraniopsis echinaster Perrier 1891:K106–107, p. 10, fig. 2; Fisher 1940: 158 –159; Madsen 1956: 29 –30, pl. 2, figs. 1–4; Bernasconi 1964: 265; A.M. Clark & Courtman-Stock 1976: 90 (footnote); Codoceo & Andrade 1979: 158; Bernasconi 1980: 255 –256, pl. 3, figs. 3, 4; A.M. Clark 1984, figs 1A, 2A; Clark & Downey 1992: 222; AM Clark 1993: 235; Mutschke & Mah 2009: 816; Mah & Foltz 2011: 771, fig. 1 (in tree), 776.

Lahillea mira (de Loriol 1904): 30–34, pl.3, fig. 1

Poraniopsis mira Fisher 1911: 260; Barattini 1938: 20; Fisher 1940: 159; Bernasconi 1964: 265; 1973: 307–308; 1980: 254–255, pl. 2, figs 3,4; Jangoux 1985: 27; Clark & Downey 1992: 222

Synonymy of P. mi r a: Poraniopsis mira and P. echinaster were summarized by Bernasconi (1980) and Clark and Downey (1992: 222) who identified the primary morphological distinctions as the numerous, small tegumentary spinelets, the differing abactinal spine length and shape and similar/dissimilar sized furrow vs. subambulacral spine size. Characters used to distinguish between these two species are variable and do not support a consistent taxonomic boundary, especially when compared with the P. mira lectotype (= Lahillia mira deLoriol, Geneva Museum #71730) (Fig. 9 E). A specimen identified by Bernasconi as P. m i r a (USNM 9491, fr. Uruguay) possesses minute skeletal ossicles and spinelets embedded in the skin which were used to distinguish the two species in her key (Bernasconi 1980) and were consistent with those present in Poraniopsis echinaster. Abactinal spines in P. echinaster varied from sharp and pointed (e.g. USNM 1082732) to those with more clavate spines (USNM E11503). The P. m i r a lectotype has more pronounced clavate spines (Fig. 8 E), which cover the abactinal surface but ultimately overlap in shape with those in P. echinaster. USNM 1082732 (R=3.2) and USNM E09491 (R=4.5) both show subambulacral and furrow spines displaying similar sizes but with spine shapes consistent with those on the lectotype. Conversely, USNM E11503 shows abactinal spines similar to those on the lectotype but with dissimilar subambulacral-furrow spine sizes.

Bernasconi (1980) figured P. m i r a with what Clark and Downey (1992) described as having shorter spines, approximately 1.0– 1.5 mm in length at R= 40–50 mm (e.g., USN E11503). Spine length varies widely among individuals. One specimen, USNM 1082732 (R=3.2) bears comparably located abactinal spines 2.0–3.0 mm, whereas a larger specimen from the same lot (R=3.8) possesses shorter, stubbier spines with 1.0–2.0 mm. The absence of morphological distinctions supports the conclusion that Poraniopsis mira (deLoriol 1904) is not a separate taxon and should be synonymized into Poraniopsis echinaster Perrier 1891.

Occurrence. Straight of Magellan, Chile and South Atlantic: Uruguay, Brazil to S. Argentina, Bouvet Island, west coast of South Africa, Southern Indian Ocean (Coral Seamount). 0– 700 m.

Material examined. South Pacific (Chile). USNM 1082729 Straits of Magellan (west mouth of strait) 52º41’S, 74º35’ W to 52º45’S 74º28’W, 188– 247 m. Coll. R/V Eltanin, US Antarctic Research Program (2 dry specs. R=4.1, r=1.8; R=4.4, r=2.5); USNM 1082732 west mouth of Straits of Magellan 52º41’S, 74º35’W, to 52º45’S, 74º28’W, 188–247 m, Coll R/V Eltantin, USARP (2 dry specs. R=3.8, r=1.6; R=3.2, r=1.2); USNM E11503 South of Wellington Island, 50º11’30”S, 74º47’ W (1 dry spec. R=3.6, r=1.9); USNM E15939 Pumalin, W. of Isla Talcon, Gulf of Corcovado, Chile. Intertidal. 42º42’S, 72º52’W. Coll. James H. McLean, Nov. 4,5,6, 1975. (2 dry specs. R=2.1, r=1.0; R=2.2, r=0.8). MNHN no number. Off the coast of Zapallar, Chile, 350 m. Coll. P.M. Arnaud, “Golden Wind” GW 67, Sept. 27 1977 (6 wet specs. R=5.2, r=2.9; R=3.9, r=1.8; R=3.8, r=1.4; R=3.3, r=1.0; R=3.0, r=1.0; R=2.4, r=0.7); MNHN no number. Off the coast of Coquimbo, Chile, 450 m. Coll. P. Arnaud, “Golden Wind” GW 4, Aug 6, 1981 (7 dry specs. R=3.6, r=1.8; R=3.7,r=1.5; R=3.3, r=1.7; R=2.8, r=1.4; R=2.7, r=1.3; R=3.0, r=1.5; R=3.2, r=1.5; R=2.2, r=1.5). South Atlantic. USNM E 9491, Cabo Santa Maria, Uruguay, 119–128 m, coll. R/V Undine, C. Alexanderson (1 dry spec. R=4.5, r=1.9); CASIZ 174643 Bouvetoya (Bouvet Island), South Atlantic 54º21.36’S 3º10.30’E, 455–462 m, Coll. S. Lockhart, 23 June 2004 (1 wet spec. R=2.5, r=0.8). Lectotype (Holotype) MHNG-INVE-71730 (Muséum d'histoire naturelle, Geneva) P. mi ra, Argentine, Golfe San Mathias Patagonie (1 dry spec. R=5.0, r=2.3). South Africa. SAEON collection # 4, West coast of South Africa. -31.1546, 16.8832), 229 m. Coll. L. Atkinson, trawl 112-3189, st. A31483 (1 wet spec. R=4.0, r=1.5); #8 West coast of South Africa. –30.1509, 16.4007, 174 m. Coll. L. Atkinson, trawl 054-2202, st. A32193 (1 wet spec. R=9.2, r=3.8); #17, South Africa (no other data), (1 dry spec. R=1.6, r=0.8). South Indian Ocean. NHM 680 Coral Seamount, 41º21.7673’S, 42º54.9067’E to 41º22.4’S, 42º54.6’E ~ 700 m depth. Coll. R/V James Cook via ROV (1 wet spec.)