Coralliidae

Tu, Tzu-Hsuan, Altuna, Álvaro & Jeng, Ming-Shiou, 2015, Coralliidae (Anthozoa: Octocorallia) from the INDEMARES 2010 expedition to north and northwest Spain (northeast Atlantic), with delimitation of a new species using both morphological and molecular approaches, Zootaxa 3926 (3), pp. 301-328 : 324

Key to the species of Coralliidae from the Atlantic Ocean (modified from Bayer 1964)

1 Autozooids retractile within short, hemispherical cortical mounds; long spindles in the tentacles absent... 2 ( Fig. 2 , 5 A, 8A)

- Autozooids contractile, forming prominent cylinders when contracted; long spindles in the tentacles present..5 ( Fig. 10 A, B)

2 Cortical mounds distributed on all sides of the colony; double clubs absent in cortex; live colonies with cortex and axis usually red.......................................................................................... C. rubrum

- Cortical mounds distributed predominantly on one side of the colony; double clubs abundant in cortex; live colonies with cortex white, yellow or pinkish; axis yellowish or white.......................................................... 3

3 Elongated 8-radiates ( Fig. 9 Ae, Be; higher than 0.1 mm) in both cortex and cortical mounds present; double clubs wider than high (0.027 × 0.034 – 0.041 × 0.064 mm)................................................. C. johnsoni ( Fig. 8 , 9 )

- Elongated 8-radiates in both cortex and cortical mounds absent................................................. 4

4 Cortical mounds with eight obvious lobes extending to the base; regular double clubs without apparent lateral projections; double clubs (0.042 × 0.048 – 0.074 × 0.078 mm) with similar width and height, cortex yellow or white; phylogenetically classified in Clade IA......................................................................... C. medea ( Fig. 5 )

- Cortical mounds without eight obvious lobes extending to the base; regular double clubs mostly with apparent lateral projections; double clubs (0.040 × 0.043 – 0.057 × 0.064 mm) with more prolonged and closer heads; live colonies with cortex pinkish, yellowish in ethanol; phylogenetically classified in Clade II......................... C. occultum n. sp. ( Fig. 2–4 A)

5 Double clubs not present or rare.......................................................................... 6

- Double clubs abundant................................................................................. 7

6 Eight-radiates predominate, 6- and 7-radiates common; elongated and symmetrical 8-radiates present; live colonies with white to lightly pink cortex, snow white axis....................................................... C. niobe ( Fig. 7 C)

- Six-, 7-, and 8-radiates predominate; elongated and symmetrical 8-radiates absent; live colonies with deep pink to red cortex, red axis................................................................................. C. bathyrubrum

7 Heads of double clubs smooth with weak protuberances; branching in one plane extremely profuse; live colonies with ochraceous yellow cortex and orange autozooids....................................................... C. maderense

- Heads of double clubs rough with obvious protuberances; branching in one plane moderately dense; live colonies otherwise coloured............................................................................................ 8

8 Double clubs large, with two jagged-edged heads decorated by hypertrophied rays or pointed projections; live colonies white with slightly pinkish autozooids......................................................... C. bayeri ( Fig. 7 A, B)

- Double clubs small, with two not well separated heads decorated by blunt projections; live colonies yellow to cream with vermilion red or pink autozooids............................................................ C. tricolor ( Fig. 10 )

Figures

FIGURE 2. Corallium occultum n. sp., Avilés Canyon System, Stn. DR 18. (A) Holotype, “ front ”, “ back ” and close views (MNCN 2.04 / 1128). (B) Paratype (MNCN 2.04 / 1129), Avilés Canyon System, Stn. DR 18, close view of cortical mounds. (C) Right image, paratype (MNCN 2.04 / 1130), Avilés Canyon System, Stn. DR 16. Arrows indicating siphonozooids.

FIGURE 3. Corallium occultum n. sp., holotype (MNCN 2.04 / 1128), Avilés Canyon System, Stn. DR 18. (A) Cortical sclerites. (B) Sclerites from the autozooids.

FIGURE 4. (A) Cortical sclerites of Corallium occultum n. sp., paratype (MNCN 2.04 / 1130). (B) Box plots indicate the width, height, and width / height ratio of double clubs from Corallium johnsoni (Gray, 1860), NHM 1933.3. 13.55 and SMF 2426; Corallium medea Bayer, 1964, USNM 52512 (holotype) and USNM 52513 (paratype); Corallium occultum n. sp., MNCN 2.04 / 1128 (holotype) and MNCN 2.04 / 1130 (paratype). The box delimits the first and 3 rd quartile, the horizontal line represents the median, and the whiskers delimit values that are within 1.5 x the inter-quartile range; values outside that range are represented by circles and considered as statistical outliers. (C) Mean (± one standard error, n = 40) of width, height, and width / height ratio of double clubs. Means within a column (in small letter) followed by the same letter are not significantly different based on multiple comparisons (at alpha = 1 % significance level).

FIGURE 5. Corallium medea Bayer, 1964. Holotype, USNM 52512. (A) Front, back and close-up view of colony. (B) Sclerites from cortex.

FIGURE 7. Corallium cf. bayeri Simpson & Watling, 2011, Galicia Bank, Stn. DR 15. (A) View of colony. (B) Cortical sclerites; double club (uppermost right) seen in top down view. (C) Corallium niobe Bayer, 1964, Avilés Canyon System, Stn. DR 16. Note modification of axis resulting from the presence of a commensal worm.

FIGURE 8. Corallium johnsoni Gray, 1860. (A) NHM 1933.3. 13.55, “ front ” and “ back ” views of colony. (B) SMF 2426, view of colony, and sclerites from the autozooids.

FIGURE 9. Corallium johnsoni Gray, 1860, NHM 1933.3. 13.55. (A) Cortical sclerites (B) Sclerites from the autozooids. Sclerites were grouped by shape: (a) crosses, (b) 6 - radiates, (c) 7 - radiates, (d) symmetrical 8 - radiates, (e) elongated 8 - radiates, (f) asymmetrical 8 - radiates, (g) double clubs, and (h) rods that are only present in autozooids.

FIGURE 10. Corallium tricolor (Johnson, 1898), SMF 9514. (A) “ Front ” view of colony, arrow indicating small raised bumps. (B) “ Back ” view of colony, black arrow indicating opening of siphonozooid; white arrows indicating the axis distorted. (C) Cortical sclerites; (a) asymmetrical 6 - radiate, (b) asymmetrical 8 - radiates, (c) symmetrical 8 - radiates, (d) double clubs. (D) Sclerites from the autozooids; (a) pharyngeal sclerites, (b) tentacle sclerites ..