Ferdina mena

Mah, Christopher L., 2017, Overview of the Ferdina - like Goniasteridae (Echinodermata: Asteroidea) including a new subfamily, three new genera and fourteen new species, Zootaxa 4271 (1), pp. 1-72 : 19-23

Ferdina mena nov. sp.

Figure 5 A–H, 6 A–D

Gosliner et al. 1996: 257; King & Fraser 2014: 341 (as Ferdina sadhensis ) Branch et al., 2010: 227 (as Nardoa variolata )

Etymology. The species descriptor is taken from the Malagasy word mena for red, alluding to this species’ red spots in each interradius.

Occurrence. Durban, Sodwana Bay and east coast of Africa (KwaZulu-Natal), South Africa, Madagascar, Mayotte, Mozambique, 0–86 m.

Diagnosis. A species distinguished by two distinct paired bald patches present on the first superomarginals observed in each interradius ( Figs 5 A, C, H) but is otherwise completely covered by granular tegument. Abactinal surface a heterogeneous mixture of large and small strongly convex plates. Marginal plates in continuous series. Superomarginals heterogeneously sized and shaped. Inferomarginals homogenous.

Taxonomic notes. This species occurs more southernly than F. sadhensis (type locality in Oman possibly extending down to Scottburgh, South Africa) and has been misidentified for F. sadhensis in field guides (e.g., Gosliner et al. 1996, King & Fraser (2014). Although collection depths are as shallow as the intertidal in Madagascar (e.g., MNHN-IE-2007-5081), most occurrence seems to be at subtidal or SCUBA depth (10–40 meters).

The interradial bare regions in Ferdina mena n.sp. shows variation within the species and in some cases within an individual. For example, MNHN-IE-2007-5032 (at R= 2.4 cm) displays at least one interradius with only one bare region and two others with none (thus having interradii superomarginals completely covered by granules). MNHN-IE-2007-5051 (at R=3.7) shows paired bare regions on all but one interradius which displays only one bare superomarginal plate. But in all the specimens examined for the species description, one or a pair of convex bare regions was consistently present.

The very heterogeneous convex plates present in F. mena n. sp. separate it from F. flavescens which displays larger overall convex plates on the body surface. Ferdina sadhensis displays the most similar appearance to F. mena and shares an abundance of heterogeneously sized convex plates. However, F. sadhensis displays more heterogenous plates, intermarginal papulae (papulae present between the superomarginal and infeormarginal series) as well as a more irregularly distributed superomarginal series. Color is also distinct as F. mena is yellow/ orange white with red highlights and dark red bald spots versus F. sadhensis which is a deep red with white armtips as well as white abactinal and marginal plates.

This species can be easily confused with small (R=~ 1.5 cm) individuals of Nardoa variolata but can be distinguished based on the absence of adambulacral spination and granulation in Ferdina . Adambulacral accessories are present in three series in Nardoa . Branch et al. (2010) misidentified this species as Nardoa variolata .

Description. Body stellate (R:r=4.1–5.6) with broad arms, rapidly tapering, small disk ( Fig. 5 A).

Abactinal surface covered with heterogeneously sized, convex plates ( Fig. 5 B) continuously covered by granules, embedded in a thin skin, which nearly completely covers the body surface. Abactinal plates round to irregular in outline with largest plates tending to be most abundant proximally. Smaller abactinal plates directly abutted against larger abactinal plates. Smaller plates (~20–25% of larger plate size) occur more distally and are more likely to be found on the distal side of the arm. These smaller plates surround the larger abactinal plates along the arms and to a lesser extent on the disk. Smaller plates tend to be more irregular in shape and more abundant along contact with superomarginal plates. Larger, more strongly convex plates forming many hemispheres along the abactinal surface. Three specimens (MNHN-IE-2007-4984, MNHN-IE-2007-4979, MNHN-IE-2007-5019) variably display lower, less pronounced, more mound-like abactinal plates. Although carinal plate series are present, they occur in an irregular fashion along each arm and appear discontinuous and/or irregularly arranged or jumbled along the surface. This pattern appears to be more pronounced in larger specimens (R= 5.2 cm) with smaller specimens showing more continuous and more serial carinal series. Granules polygonal in shape, fine, approximately seven to eight along a 1.0 mm line measured along the surface. Granular tegument extends to grooves and valleys between abactinal plates. Most specimens observed with one triangular or polygonal madreporite, but one specimen (MNHN-IE-2013-6602) with three madreporites. Specimen with three madreporites with one triangular, one irregularly round, and one weakly circular. All with well developed sulci. One specimen (MNHN-IE 2007-3969) with madreporite absent. This latter specimen, also with low abactinal plates with most nearly flat. Papulae single, present in dark colored regions around plate edges, numbering two to six per plate. No pedicellariae observed. Anus surrounded by five flattened, spatulate spines.

Marginal plates more ordered and in clearly discrete serial progression in smaller specimens (R= 2.3 cm, MNHN-IE-2007-5076) than in larger ones (R= 5.2 cm, MNHN-IE-2013-6602). Superomarginal plates were observed as much more strongly heterogeneous with differently sized plates and irregularly out of linear series, than inferomarginal series. Superomarginal plates number (arm tip to arm tip) ranges from 22–46 in smaller (R= 2.3 cm) versus larger (R= 5.2 cm) individuals, respectively. Superomarginal plates varied in outline from perfectly hemispherical in smaller specimens to larger more mound shaped but more weakly rounded plates ( Fig. 5 D). Some with strikingly smaller (<20% diameter) sized plates in series between larger plates. Present on the first two superomarginals in each interradius are two, strongly convex, smooth, bare regions centered on the middle of each superomarginal plate ( Figs 5 A, C). One individual (MNHN-IE-2013-6602) displayed only four pairs of bare regions, present out of five interradii. In most individuals all remaining superomarginal and inferomarginal plates are completely covered by the continuous layer of granular tegument present on the body surface. Inferomarginals continuous, ranging from more flattened and quadrate in shape interradially becoming more round and irregularly shaped more distally ( Fig. 5 E). No pedicellariae observed on marginal plates.

Actinal surface with two rows of intermediate plates ( Figs 5 F,G). Actinal plates on disk, irregular in shape with two large, paired triangular plates present between inferomarginals and first row of actinal plates (Fig. G). Single series of actinal plates continues for approximately 50 to 80% of the distance along the arm. Actinal plates range from flat to weakly convex. Surface covered by continuous layer of granulation as on top surface. No papulae present on actinal surface. Pedicellariae not observed.

Furrow spines present in a single row, two spines per plate ( Fig. 5 G). Granule-covered surface forms a continuous surface from the spine to the actinal surface ( Figs 5 F, G). Subambulacral spines absent. Two short, blunt spines on the tip of each oral plate projecting into mouth.

Color in life: disk and proximal arm region is white to lighter in color with dark red to orange arms and light white to yellow arm tips. Interradial bald plates dark red ( Fig. 5 H).

Specimen MNHN-IE-2007-4961 possesses a pronounced outgrowth on the abactinal surface of the arm, which appears to be an endoparasitic eulimid snail.

Notable variation: One individual (MNHN-IE-2007-5129) displayed convex, circular bare region alternating approximately every one to three plates as part of what appeared to be an extremely irregular superomarginal series. Intermarginal (i.e. between superomarginal and inferomarginal series) plates and papulae were present on this specimen. Although this was interpreted as variation across this species range, the pattern was consistent and could possibly indicate a second species should further data indicate the pattern was consistent.

Material examined. Holotype: MNHN-IE-2007-5091; Nosy Manitsa, Madagascar, 25°12.6’S, 44°12.5’E, 12– 18 m; Coll. ATIMO VATAE, TA 15 , 19 May 2010, “JS 127”;1 wet spec. R=3.7, r=0.9. Paratypes: Madagascar. MNHN-IE-2013-6602; Tany Kely , Nosy Be , Madagascar, “ Bas de pente corallienne,” 22 m; Coll. M. Pichon, 9 Oct, 1963. 1 dry spec. R=5.2, r=1.2. MNHN-IE-2007-3969; 24°35.9’S, 47°32.1’E, 86.0 m; Coll . ATIMO VATAE, N/ O Nosy be 11. St. DW 3530; 2 May 2010. 1 wet spec.; R=4.0, r=0.8. MNHN-IE-2007-4934; Baie des Galions, Madagascar, 25°9.5’S, 46°44.9’E, 9–10 m ; Coll. ATIMO VATAE, TV 16, 12 May 2010;1 wet spec. R=3.8, r=1.0. MNHN-IE-2007-4939; Before Phare Flacourt , Madagascar 25°1.3’S, 47°0.2’E, 12–16 m ; Coll. ATIMO VATAE, TV 7, 2 May 2010; 1 wet spec. R=2.8, r=0.6. MNHN-IE-2007-4941. Baie des Galions, 25°9.2’S, 46°45.4’E Madagascar 5– 6 m . Coll. ATIMO VATAE, TV 17, 12 May 2010. 1 wet spec. R=1.2, r=0.3; MNHN-IE-2007-4961; 24°59.5’S, 47°5.6’E, West Point Evatra , Madagascar, 15–17 m ; Coll. ATIMO VATAE, TR 16, 9 May 2010; 1 wet spec. R=2.7, r=0.7. MNHN-IE-2007-4975; West Point Evatra , Madagascar, 24°59.2’S, 47°05’E 2–7 m ; Coll. ATIMO VATAE, dr 15,, 9 May 2010; 2 wet specs. R=3.3, r=0.7, R=3.3, r=0.7. MNHN-IE-2007-4979; Before Phare Flacourt , Madagascar, 25° 1.3’S, 47°0.5’E, 18 m ; Coll. ATIMO VATAE, TS 2, 29 Apr 2010, “JS 318”; 1 wet spec. R=2.4, r=0.5. MNHN-IE-2007-4984; Ilot Choumare , Madagascar, 24°50.2’S, 47°16.9’E, 12–24 m ; Coll. ATIMO VATAE, TA 61, 18 m. Coll. 6 July 2010; 1 wet spec. R=3.1, r=0.5. IE- 2007-5006 ; Sud Cap Antsirabe, Madagascar, 25°2.8’S, 46°59.6’E, 6–12 m ; Coll. ATIMO VATAE, TR 9, 2 May 2010; 1 wet spec. R=3.8, r=1.1. MNHN-IE-2007-5019; Before Phare Flacourt , Madagascar, 25°1.3’S, 47°0.2’E, 12–16 m ; Coll. ATIMO VATAE, TV 7, 2 May 2010; 1 wet spec. R=3.1, r=0.7. MNHN-IE-2007-5032; Baie de Fort Dauphin , Madagascar, 25°0.8’S, 47°0.9’E, 21 m ; Coll. ATIMO VATAE, TR 3, 29 June 2010; 1 wet spec. R=2.4, r=0.4. MNHN-IE-2007-5051; Ilot Choumare , Madagascar, 24°50.2’S, 47°16.9’E, 12– 24 m .; Coll. ATIMO VATAE, TA 41, June 7, 2010, “ PL Photos ”; 1 wet spec. R=3.7, r=0.9. MNHN-IE-2007-5076; Ilot Choumare , Madagascar, 25°12.7’S, 44°8.5’E, 20– 22 m .; Coll. ATIMO VATAE, TA 22, 25 May 2010, “JS 320”; 1 wet spec. R=2.3, r=0.5. MNHN-IE-2007-5078; Nosy Manitsa , Madagascar, 25°12.6’S, 44°12.5’E, 12–18 m ; Coll. ATIMO VATAE, TA 22, 19 May 2010, “JS 128”; 1 wet spec. R=2.8, r=0.6. MNHN-IE-2007-5081; Nosy Manitsa , Madagascar, 25°23.1’S 44°14.0’E, 0–1.0 m; Coll . ATIMO VATAE, TA 20, 20 May 2010, “JS 159”; 1 wet spec. R=2.7, r=0.6. MNHN-IE-2007-5105; Banc Tozer , grotto, Madagascar, 25°12.7’S, 44°8.5’E 20– 22 m .; Coll. ATIMO VATAE TA 22, 25 May 2010, “JS 318”; 1 wet spec. R=3.7, r=0.9. MNHN-IE-2007-5106; Madagascar, no other data; Coll . ATIMO VATAE, TA18, 18 May 2010 “JS 168”;1 wet spec. R=3.3, r=0.8. MNHN-IE-2007-5114; Cap Sainte Marie , Madagascar, 25°35.4’S, 45°7.8’E 9– 17 m .; Coll. ATIMO VATAE, TA 25, 24 May 2010, “JS 293”; 1 wet spec. R=3.9, r=0.7. MNHN-IE-2007-5104; Cap Saint Marie , Madagascar, 23°33’52” 45°6’53.5’E, 18– 20 m .; Coll. ATIMO VATAE, TA 26; 1 wet spec. R=3.5 r=0.9. MNHN-IE-2007-5129; Cap Sainte Marie , Madagascar, 25°33’21.89 S 45°6’56”, 16–18 m ; Coll. ATIMO VATAE, TA 27, 24 May 2010; 1 wet spec. R=3.0 r=0.8. South Africa: Iziko Museum MB-A 081526, East coast of South Africa, Dive 9, 18.0 m , 4 July 1986; Coll. G.C. Williams; 1 dry spec. R=3.2, r=1.2.

Figures

FIGURE 5. Ferdina mena n. sp. Holotype, MNHN-IE- 2007 - 5091. Scale Bar = 4.0 mm. A. Abactinal surface. B. Abactinal surface detail. C. Interradial superomarginals showing paired bare region on each plate. D. Abactinal-lateral view showing superomarginals and adjacent plate series. E. Actinolateral view showing inferomarginals and adjacent plate series. F. Oral surface. G. Oral region and adambulacral furrow spination. H. In situ image of living specimen (not collected) Aliwal Shoal, South Africa (image by Georgina Jones).