Henricia aspera Fisher, 1906

Shin, Michael Dadole Ubagan and Sook, 2023, A new record of a sea star, Henricia aspera Fisher, 1906 (Asteroidea: Spinulosida: Echinasteridae) from Jeju Island, Korea, Journal of Species Research 12 (2), pp. 154-157 : 156

Henricia aspera Fisher, 1906

Henricia aspera Fisher, 1906: 127 ; 1911: 293; Hayashi, 1940: 154; Djakonov, 1950: 87; Hayashi, 1973: 61; Mah, 2022: 369100.

Material examined. One specimen, adjacent waters of Moseulpo Harbor, 8 Sept. 2015.

Description. Arms five, long, semi-cylindrical, swollen arm base, gradually tapering to tips; disc small ( Fig. 1A, B ). Abactinal paxillae scattered, containing three to seven small abactinal spinelets, covered with thin integument ( Fig. 1C ). Denuded abactinal spines broad at base and rapidly tapering from middle part to tip ( Fig. 1J ). Papular areas wide with irregular shapes, containing two to nine papulae in an area; some areas bearing small ossicles ( Fig. 1C, H ). Denuded abactinal skeleton open meshed, reticulated, comprised of lobe-shaped and crescent-shaped plates; some skeleton forming semi-rounded plates ( Fig. 1G ). Madreporite sunken, situated near margin of disk, circular in form, and bearing spines similar as adjacent spines ( Fig. 1F ). Marginal plates well discernible. Denuded actinal skeleton showing three series of plates (Inferomarginal, intermarginal, and ventrolateral) which diverging near arm tip, leaving intermarginal plates wide spaces. Inferomarginal plates imbricated, elongated cross-shaped, reaching three-fourth length of arm. Intermarginal plate consisting of lobe-shaped plates, with small roundshape ossicles, reaching near half of arm. Ventrolateral plates rounded cross-shaped, showing larger size compared to adjacent plates; narrow papular areas with one or two papulae ( Fig. 1I ). Adambulacral armature composed of four to eight short, robust spinelets, inner two or three spatulate-shape, larger spines, arranged in two transverse rows or in a zigzag row ( Fig. 1D ). Oral plate bearing two spatulate spines ( Fig. 1E ). Furrow spine single.

Size. R = 70 mm, r = 17 mm, R/r = 4.1.

Habitat. Hard substrates (rocks).

Distribution. Korea (Jeju Island); Japan (Sado Island, Sagami Bay); California (Santa Barbara); Russia (Bering Island); Alaska (Pribilof Aleutian Islands).

Deposition. The collected specimen was deposited in the National Institute of Biological Resources (NIBR) in Korea.

Remarks. Henricia aspera shares common morphological characteristics with Henricia pachyderma Hayashi, 1940 , by having broad arms and wide papular areas. However, four characteristics of H. aspera set the species apart from H. pachyderma , namely: the number of abactinal spines ( H. aspera : 3-7; H. pachyderma : 5-13), the number of papulae on the abactinal side ( H. aspera : 2-9; H. pachyderma : 1-3), smaller papular areas at the actinal side, and a compact series of elongated cross-shaped inferomarginal plates ( Table 1). Our specimen has slight differences compared to the holotype description of Fish- er, 1906. In terms of the basal arm shape, our specimen is slightly swollen, while Fisher’s description does not have a swollen arm base and also slightly varies in the number of abactinal spines (our specimen: 3-7; Fisher’s description: 5-15). In addition, the size of our specimen is smaller (R = 70 mm) compared to the original specimen (R = 100 mm). The number of abactinal spines was a dis- tinctive characteristic of Henricia species, even in similar species where there was a variation in the number of spines; it was discovered to be highly reliable and stable at identifying species ( Madsen, 1987; Clark and Jewett, 2010). The Henricia species group, however, cannot be accurately divided based on a single characteristic. ( Bratova and Paskerova, 2017). However, this slight morphological difference does not make the specimens distinct from each other. Therefore, we consider that our specimen is the same species as that described by Fisher, 1906. The collected specimen of H. aspera from the near waters of Moseulpo on Jeju Island is newly reported for Korean fauna.

Figures

Fig. 1. Henricia aspera. A. abactinal side; B. actinal side; C. abactinal paxillae; D, K. adambulacral spines; E. oral part; F. madreporite; G. abactinal skeleton; H. papulae (arrows); I. actinal skeleton: inferomarginal plates (i); intermarginal plates(in), ventrolateral plates (v), adambulacral plates (a); and J. abactinal spines. Scale bars:A, B=2 cm, C-I=1 mm, J=100 μm, K =500 μm (J, K, SEM images).