Ferdina Gray 1840

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 : 17-18

Ferdina Gray 1840

Gray, 1840: 282; 1866: 12–13; Fisher 1919: 370; H.L. Clark 1921: 58; Livingstone 1931: 305; A.M. Clark 1967: 191; Marsh & Campbell 1991: 213.

Included species. F. flavescens Gray 1840 ; F. mena nov. sp., F. sadhensis Marsh & Campbell 1991 .

Type species. F. flavescens Gray 1840

Diagnosis. Body stellate, elongate arms, small disk (R/r=3.9–5.6). Arms cylindrical with flattened actinal surface. Broad at base, but more tapering at tips Body surface covered by strongly fine to coarse granules extending from base of furrow spines. Bald surfaces present on first two paired superomarginals in each interradius F. mena n. sp., otherwise absent in other Ferdina spp. Large convex abactinal plates round to dome like in shape overlying smaller, irregularly round plates. These larger plates vary in size, distribution and abundance relative to the smaller plates. Single papular pores present between smaller abactinal plates.

Marginal plates variably regular or irregular in series, shape and size. Superomarginals variably strongly convex to more weakly so. Inferomarginals variably convex. Smaller secondary abactinal plates as well as papular pores present between larger marginal plates in some species. Superomarginals and inferomarginals in distinct, but recognizable series in F. mena , n. sp. whereas others show marginal plates in irregular, jumbled, sometimes completely discontinuous series. Inferomarginals tend to be in more recognizable series. Both superomarginal and inferomarginals tend to be in more regular and continuous distally along arm.

Actinal surface present in three to five distinct chevron like series extending only partially along the arm. Actinal plates vary in shape from more rounded to irregularly polygonal. Granulated tegument also variably fine to coarse grained depending on species. Papulae absent from actinal surface. Granulated tegument extends to lower base of furrow spines which occur in a single series along the tube foot groove. Furrow spines, thick with blunt tips, round to quadrate in cross-section, one or two per adambulacral plate. Adambulacral plates with no accessories other than the granulated tegument covering the body surface. Granulated tegument similarly covers the oral plate which has no other surficial accessories. One spine present on each oral plate (i.e., two directed into mouth) but as with the furrow spines, they are short, blunt with basal portion covered by granulated tegument.

Taxonomic comments & history. Ferdina is known primarily from the western Indian Ocean from intertidal to subtidal depths with known species occurring from Oman to Europa Island and Madagascar. Nothing is known about its biology and ecology.

Historically, Ferdina was described by Gray (1840) to accommodate F. flavescens and F. cumingi . Ferdina cumingi has since been reclassified into Neoferdina and many other Ferdina -like taxa have been recognized in subsequent work (see Marsh and Campbell 19991 for full review). In spite of this, relatively little work has been published on Ferdina itself. Marsh and Campbell (1991) provided a key to the “ Ferdina group of genera” and distinguished Ferdina from other similar genera based on the presence of a bare marginal plates as well as size and morphology of abactinal and marginal plates. However, based on the description of the new Ferdina sp. described below, it is apparent that the presence of bare spots within the Ferdina “group” is more variable than had been previously documented. Its use as a key character in the key should be regarded carefully.