Kanakaster

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 : 24-25

Kanakaster nov. gen.

Etymology. This genus is named for the Kanak, the native people of New Caledonia.

Type species. Kanakaster convexus (by designation)

Diagnosis. Kanakaster is characterized by the presence of crystalline nodules on the surface of the abactinal plates and on both marginal series (e.g., Fig. 12 D) below a coarse granular tegument covering the body surface (e.g. Fig. 7 B,C). Three to four enlarged granules, relative to the other granules on the surface, are present around every papular pore. Weakly expressed to irregularly shaped bare patches present or absent on superomarginal plate surface.

Taxonomic comments. Kanakaster n. gen. is diagnosed by the presence of glassy granules on the abactinal and marginal plate surface (e.g., Fig. 12 D), the granular tegument covering the complete surface and the small bare areas on the surface of each marginal plate. It shares several characters with Bathyferdina n. gen. which is likely its sister taxon.

Kanakaster n. gen. shares a superficial resemblance with Stellasteropsis in that they both lack any modified accessories on the adambulacral plates (e.g. Fig. 7 E) and analogously possess a continuous granular tegument on the body surface. However, Stellasteropsis possesses six to seven small furrow spines versus one to three on Kanakaster spp. Also, granules in Stellasteropsis are directly present on the body surface and leave pitting on superomarginals and other surfaces when removed. Granular tegument on Kanakaster and related ferdiniine goniasterids are embedded in a tegument or membrane and do not leave concavities on the plate surface. The granular tegument is more resilient to removal efforts and is not easily abraded.

Skeletal differences between Kanakaster and Stellasteropsis are also evident. Stellasteropsis has relatively wide marginal plate and polygonal to flattened abactinal plates. Comparable species of Kanakaster , including K. balutensis n. gen, n. sp. and K. solidus have convex abactinal plates and more elongate and blockier marginal plates. Some species such as K. larae n.sp. do possess abactinal and superomarginal plates which are more similar to Stellasteropsis but a well-developed granular tegument is present in Kanakaster n. gen.

This genus represents a widely occurring complex with occurrence across the subtropical Indo-Pacific from New Caledonia to South Africa and north to the Philippines, present on continental shelf settings (120–500 m). Species in Kanakaster n. gen. vary primarily based on body form and marginal plate arrangement and number. Accessory characters, such as the granular tegument and especially adambulacral granule covering and other adambulacral accessories are consistently similar across species.

Two species, K. plinthinos n. sp. and K. discus n. sp., included consistently small-sized (R<2.0 cm) individuals. These individuals could not be reconciled as or with small-sized specimens of the other species of Kanakaster n.sp.. However, it remains possible that larger sized individuals displaying a different adult morphology of these species remain to be discovered.

Included species. K. balutensis n.sp., K. convexus n.sp., K. discus n. sp., K. larae n. sp., K. plinthinos n. sp., K. solidus n.sp.

Figures

FIGURE 7. Kanakaster balutensis n. gen., n. sp. Holotype, CASIZ 185668. A. Abactinal surface. Scale bar = 8.0 mm B. A bactinal plate detail. Scale bar = 3.0 mm. C. Abactinal-lateral view showing superomarginal plate detail. Scale bar = 2.0 mm D. Oral surface. Scale bar = 8.0 mm E. Detail of oral region, furrow spines. Scale bar = 3.0 mm

FIGURE 12. Kanakaster solidus n. gen., n. sp. Holotype, MNHN-IE- 2013 - 6850. Scale Bar = 3.0 mm. A. Abactinal surface. B. Abactinal surface showing details on plates. C. Lateral view showing superomarginal and inferomarginal surface details. D. Denuded surface detail on abactinal and superomarginal plates showing crystalline nodules embedded on plates. E. Actinal surface. F. Detail on oral surface showing furrow spines, mouth and pedicellariae.