Henricia elachys Clark and Jewett, 2010

Ubagan, Michael D. & Shin, Sook, 2016, A new record of sea star genus Henricia (Asteroidea: Spinulosida: Echinasteridae) from Jeju Island, Korea, Journal of Species Research 5 (3), pp. 351-354 : 353

Henricia elachys Clark and Jewett, 2010

ẅêj"äṻṵq (신AE) ( Fig. 1 A­K)

Henricia elachys Clark and Jewett, 2010 : pp. 22, figs. 59­62, 64; Mah, 2015: 509327.

Material examined. Three specimens were collected on 8 September 2015, near waters of Moseulpo , Jeju Island, Korea, at 50­90 m depth by fishing net, Shin, S. and D. Kim .

Description. Slightly broad disc. Arms five in number, short, moderately inflated arm base. Dorsal skeleton im­ bricated forming irregular size. Dorsal paxillae forming in groups, slender, pointed tips bearing three to fourteen spinelets. Papular area small, containing two to five papulae, not in regular form. Madreporite circular in form, slightly inflated. Ventrolateral plates slightly convex, reaching up to three­fourths length of arm. Inferomarginal plates larger than ventrolateral plates, reaching tip of arm. Supermarginal plates almost the same size of inferomarginal plates, reaching near tip of arm. Marginal plates relatively distinct. Adambulacral armature with ten to fourteen slender and stout spinelets. Furrow spine single.

Size. R = 27­32 mm, r = 7­10 mm, R/r = 3.2­3.9.

Habitat. Coral reefs and under rocky places.

Distribution. Korea (Jeju Island), Alaska (Rat Island of Aleutian Islands).

Remarks. This species as first recorded by Clark and Jewett, 2010 from Rat Island of Aleutian Islands in southwest Alaska. Our H. elachys specimen was collected from temperate area of Jeju Island in Korea, This species can tolerate cold region to temperate zone. In terms of body forms, both possessed slender dorsal spinules but H. elachys of Clark and Jewett (2010) has sixteen to twenty­seven spines in a group. Other body parts such as ambulacral spines and oral part agree with the description of H. elachys by Clark and Jewett (2010). The examination showed that our specimens differ from Henricia tumida . Our specimen has numerous (ten to fourteen) adambulacral spines which occur in two or three rows in H. elachys , while in H. tumida a single often irregular or staggered row of four or five adambulacral spines; smaller, more numerous papulae two to five per area while H. tumida usually one, rarely two, large papulae.

Figures

Fig. 1. Henricia elachys. A. dorsal view; B. ventral view; C, J. dorsal spines; D, K. adambulacral spines; E. oral part; F. madreporite; G. dorsal skeleton; H. ventral skeleton: adambulacral plate(A), ventrolateral plate (V), inferomarginal plate (I), supermarginal plate (S); I. furrow spines. Scale bars:A, B=2 cm; C, D, G, H=2 mm; E, F=1 mm; I, J=100 μm, K=200 μm.