Neoferdina longibrachia Kogure & Fujita 2012

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 : 54

Neoferdina longibrachia Kogure & Fujita 2012

Figure 18 A–F

Kogure & Fujita 2012: 252

Occurrence. Kumejima Island , southwest Japan, 151– 160 m .

Taxonomic comments. One examined specimen ( CASIZ 218861 ) from Balut Island in the Philippines showed very close correspondence with Kogure and Fujita’s (2012) description. The Philippine specimen shows more triangular-shaped arms, has larger bald patches on each superomarginal plate, slightly more bald patches on proximal inferomarginals, and has two additional rows of abactinal plates on each arm (three in the holotype, five in CASIZ 218861 ). But shares almost all other characters such as the absence of bald patches on the interradial inferomarginal plate surfaces and a high R/r ratio with an elongate arm length (R/r=4.5 vs. 5.7 in N. longibrachia ).

When compared with N eoferdina insolita Livingstone 1936 , N. longibrachia Kogure and Fujita 2012 displays few to no character differences. The latter species displays elongate arms (R/r=5.7), possesses elliptical-shaped bare regions on the superomarginals, and have polygonal rather than elongate carinal plate shape. Carinal plate shape, however, is likely growth related leaving only the elongate arm length (R/r= 5.7 in the N. longibrachia specimen at R= 3.6 cm vs. R/r= 3.07 in the N. insolita holotype at R=2.0) and differently shaped marginal plate bare regions as differences between the two species (elliptical in N. longibrachia , more circular in N. insolita ). However, given the morphological range of specimens within other Neoferdina species, these differences are easily be attributed to character variation especially given the distance observed between the N. insolita and N. longibrachia . Both of these species share the presence of an abactinal covered granulated tegument, a similar number of marginal plates and regular bald regions on each superomarginal; this taken in conjunction with the weak character differences implies synonymous species. Habitat depth between the two species (shallow reef for N. insolita versus 151–160 m for N. longibrachia ) is also different.

The summary assessment of poor character differences versus greater shared characters suggests synonymy of the two species but because putative cryptic species complexes are likely within other Neoferdina species (e.g., N. cumingi ) and because there are relatively few numbers of specimens available for both species, I retain the two species as separate until further evidence can test these relationships.

Material examined. CASIZ 218861 , Balut Island , Philippines, Coll. Tangle net, 80–150 m. R=3.6 r=0.8.

Figures

FIGURE 18. Neoferdina longibrachia. CASIZ 218861, Scale Bar = 4.0 mm. A. Abactinal surface. B. A bactinalsuperomarginal surface detail C. Lateral view showing superomarginal and inferomarginal surface and body thickness. D. Abactinal-lateral view showing abactinal and superomarginal detail. E. Actinal surface F. Arm tip showing details along superomarginal plate series.