Isostichopus maculatus subsp. maculatus

Isostichopus maculatus maculatus (Greeff, 1882) Figs 1Z –H’, 3A–D, 4C, 5A, 9, 10C, 11C, 12–14; Tables 1–3 Stichopus maculatus Greeff, 1882: 158. Stichopus maculatus – Théel 1886: 195. — Sluiter 1910: 333. — Ancona-López 1957: 7. Isostichopus badionotus – Clark 1922: 55. — Cherbonnier 1975: 631–637, pl. 1a–c figs 1a–g, 2h–o. — Pawson 1978: 27–28, fig. 11m. — Pérez-Ruzafa et al. 1999: 54. — Entrambasaguas 2008: 134–138. — Entrambasaguas et al. 2008: 479–481. Isostichopus cf. badionotus – Wirtz et al. 2020: 38. Isostichopus maculatus maculatus – Borrero-Pérez et al. 2022: 180. Isostichopus sp. ‘maculatus’ – Purcell et al. 2023: 146–147. Original name Stichopus maculatus Greeff, 1882. Current status Isostichopus maculatus maculatus (Greeff, 1882). Name-bearing type Neotype USNM E16150, neoparatype USNM E16151. Type locality English Bay, Ascension Island for the neotype, instead of Rolas Island, São Tomé for the holotype. Diagnosis White spots as white granules on the skin (Figs 1Z –H’, 14); table ossicles from top of the dorsal papillae in two shapes, large, regular Isostichopus tables 58–86 (x = 71) µm high (Fig. 2B) and modified “ maculatus ” tables 60–108 (x = 86) µm high (Figs 2D, 10C, 12C, 13A); distributed in the Mid and East Atlantic (Fig. 5A); mtDNA divergence from other species of the genus>8.2% in COI-Fr1 (barcoding region),> 9.5 in COI-Fr2 and>8.2% in 16S; between subspecies 1.4%, 1,9% and 0.4% respectively (Table 2). Material examined Neotype (here designated) ASCENSION ISLAND • 1 spec. (L = 105 mm); Ascension Island, English Bay, Station number RBM-ASC21; 1971; R. Manning leg.; USNM E16150. Neoparatype (here designated) ASCENSION ISLAND • 1 spec. (L = 125 mm); Ascension Island, Southwest Bay, Station number RBM-ASC9; 1971; R. Manning leg.; USNM E16151. Other material EAST ATLANTIC – Cape Verde • 1 spec. (L = 55 mm); São Vicente Island, Mindelo; 16.889267° N, 25.000642° W; 24 Aug. 2015; P. Wirtz leg.; ImuCV1, only images and tissue (used) • 1 spec. (L = 85 mm); same data as for preceding; ImuCV2, only images • 1 spec. (L = 120 mm); same data as for preceding; ImuCV3, only images • 1 spec. (L = 110 mm); same data as for preceding; ImuCV4, only images • 1 spec. (L = 145 mm); Santiago Island, Tarrafal; 15.275056° N, 23.758656° W; 28 Oct. 2015; P. Wirtz leg.; ImuCV5, only images • 1 spec.; same data as for preceding; ImuCV6, only images • 1 spec.; same data as for preceding; ImuCV7, only images and tissue (used) • 1 spec.; same data as for preceding; ImuCV8, only images • 1 spec.; same data as for preceding; ImuCV9, only images • 1 spec. spotted dark pattern; same data as for preceding; ImuCV10, only images and tissue (used). – São Tomé and Príncipe • 3 specs; São Tomé; 0.273383° N, 6.476564° E; N. Vasco-Rodríguez leg.; only images • 5 specs; Ilha do Principe; 1.606606° N, 7.355° E; R. Haroun leg.; only images. – Senegal • 1 spec.; Dakar – Îles Madeleines; UF16295. – Sierra Leone • 1 spec.; 8.135025° N, 13.198139° W; P. Wirtz leg.; only images. – Liberia • 1 spec.; Kligba, Rivercess County; FAOLIB08 • 1 spec.; same data as for preceding; FAOLIB09 • 1 spec.; Artah Beach, Sasstow Grand Kru County; FAOLIB10. – Nigeria • 2 specs; 4.528551° N, 5.491359° E; fishermen leg.; only images. – Gabon • 1 spec.; Libreville; 0.393065° N, 9.427977° E; P. Wirtz leg.; only images. MID ATLANTIC – Ascension Island • 2 specs (L = 70–90 mm); Pan Am Base; depth 12–14 m; K. Jourdan leg.; USNM E17246 • 1 spec. (L = 10 mm); English Bay, Station number ASC3A; 7.93° S, 14.4° W; 1 Jul. 1976; M. Jones leg.; USNM E16166 • 1 spec. (L = 35 mm); Porpoise Point NE Side, Station 80-28; 7.9017° S, 14.355° W; depth 10.7–12.2 m; 27 Jul. 1980; Ascension I Expedition, Grice Marine Biological Laboratory exped.; USNM E34268 • 1 spec.; English Bay, One Hook; 7.893231° S, 14.387247° W; 9 Nov. 2015; P. Wirtz leg.; ImuASI1, only images and tissue (used) • 1 spec.; same data as for preceding; ImuASI2, only images and tissue (used) • 1 spec.; same data as for preceding; ImuASI3, only images • 1 spec.; Georgetown Town Pier; 7.924708° S, 14.414214° W; 15 Nov. 2015; P. Wirtz leg.; ImuASI4, only images and tissue (used) • 1 spec.; same data as for preceding; ImuASI5, only images. Description EXTERNAL APPEARANCE. Medium species, up to 220 mm long (Greeff 1882), examined specimens 55– 145 mm long (n = 7, neotype: 150 mm long (contracted); neoparatype: 125 mm long). Body loaf-like, length/width ratio 3.3± 0.9 (n = 5, 1.6–4.3, neotype 1.6, paratype 2.6). Specimens convex or somewhat quadrangular in cross section; rounded in the anterior and posterior parts (Figs 12B, 14). Contracted neotype tapering posteriorly and anteriorly (Fig. 12A). Body wall firm and thick (2–5 mm thick in the neotype). Anus supra-terminal, circular and surrounded by large papillae. Mouth directed ventrally, encircled by a collar of large papillae (2–3 mm high in the neotype). Large peltate tentacles 20, about 5–6 mm long, and shield 5–6 mm wide, in the neotype partially retracted. Dorsal papillae medium to large, wart-like; conical in the neotype (up to 5 mm high and 3 to 5 mm wide at the base) and neoparatype, usually scattered irregularly, in some specimens, including neotype and neoparatype, arranged in two irregular rows along each flank, defining a slightly quadrangular shape; smaller papillae irregularly arranged, usually wart-like, sometimes rounded and low with a thin tip in live specimens. Dorsal papillae less obvious than lateral ones; lateral papillae conical and large, sharply defining the dorsal and ventral surface (Fig. 14). Papillae in preserved specimens conspicuous (Fig. 12A–B). Ventral surface densely covered with large cylindrical pedicels, arranged in three longitudinal rows barely visible, most retracted in the neotype, but most relaxed in the neoparatype (2–3 mm long, 1 mm wide) (Fig. 12A–B). COLOR AND BODY WALL APPEARANCE. Body wall opaque and smooth, not translucent, nor rugose. Color extremely variable, four main color patterns (Figs 1, 14): (1) Uniform pattern (U) (Fig.1Z): uniform dark red, specimens of this color are rare. (2) Dark and white color pattern (DW) (Fig. 1 A’–D’): red, orange, or brown background with white irregular blotches of different shapes and sizes, arranged in longitudinal or transversal orientations; a dark line occasionally surrounding white blotches. The white irregular blotches with off-white spots as white granules, not rugose. (3) Light and sharp dark color pattern (LSD) (Fig. 1 E’–F’): lighter background in brown, beige, white, pink colors, and sharp darker irregular blotches in brown or brown-orange of different size and irregularly arranged. The lighter background area with white spots as white granules, not rugose; most lateral papillae with spiral lines from the base to the tip, which are darker than the background. (4) Dark green and light papilla pattern (DGL) (Fig. 1 G’–H’): dark green color with white spots as white granules in the background and light-yellow papillae, with darker green blotches in some specimens. DGL color pattern resembling the reticulated pattern color of I. fuscus, in live and preserved specimens. Preserved, neotype and neoparatype (Fig. 12A–B) with dark brown background with the biggest dorsal and lateral papillae conspicuous and lighter in a yellow-brown color; white granules present in the dorsal side; some papillae with a spiral line from the base to the tip; tentacles, ventral surface and pedicels of the same color as the dorsal and lateral papillae. INTERNAL ANATOMY (based on USNM E16150, Neotype, and USNM E16151, neoparatype, specimens 105–125 mm long). Calcareous ring 14 mm in diameter, radial elements roughly quadrangular, 5 mm wide and 6 mm long, with four anterior small lobes, dorsal radial plates with posterior projections longer (1.5 mm long) than those of the ventral plates (0.5 mm long); interradial elements about half as wide as radial elements (3 mm wide), pointed anteriorly with concave posterior margin (Fig. 4C). Neotype and neoparatype stone canal irregularly helical, about 10 and 12 mm long respectively, including the ending flat, leaf-like 4 and 6 mm long madreporite, broken free in the neotype; stone canal in good condition, attached to the dorsal tegument in the neoparatype. Tentacle ampullae variable in size, 10 to 21 mm long in the neotype and about 8 to 16 mm in the neoparatype. One elongated Polian vesicle, about 17 mm long by 3.5 mm wide in the neotype and 21 mm by 4 mm in the neoparatype. Gonads in two tufts, one on either side of dorsal mesentery, branched in cylindrical tubes about 0.5–1 mm wide, extending 50 mm from the anterior to posterior body and filled with eggs 31–64 μm diameter in the neotype (Fig. 11C), and extending 24 mm and filled with sperm in the neoparatype (Fig. 11C). Longitudinal muscles divided, about 8 mm wide, attached to body wall medially in both neotype and neoparatype. Respiratory trees inserted near the anterior cloaca, arising from a common stem 12 and 11 mm long in the neotype and neoparatype respectively; then divided in a left tree about 67 and 72 mm long and a right tree about 50 and 60 mm long, extending along the intestine. OSSICLES (based on USNM E16150 (neotype, SEM images); USNM E16151 (neoparatype); USNM E17246 (for mouth membrane); fifteen not collected specimens (only tissue for dorsal papillae), specimens 55–145 mm long). Dorsal papillae with regular Isostichopus tables (Fig. 2A–B), modified maculatus tables (Fig. 2D), few C-shaped ossicles, perforated plates, and large rods (Fig. 13A). All types of ossicles present in all the sizes examined. Modified maculatus tables not common in some specimens, in which only large and stout regular Isostichopus tables are present. C-shaped deposits 54–90 (x = 69) µm long, not abundant even on the top of the papillae, but more common in the neoparatype; S-shaped ossicles not observed. Tables varying in shape from the top to the base of the papillae; at the top numerous modified maculatus tables 60–79