Aleutihenricia federi, Clark, Roger N. & Jewett, Stephen C., 2010

Clark, Roger N. & Jewett, Stephen C., 2010, A new genus and thirteen new species of sea stars (Asteroidea: Echinasteridae) from the Aleutian Island Archipelago, Zootaxa 2571, pp. 1-36 : 8

Aleutihenricia federi sp. nov.

Figures 5–11

Type locality: Alaska, Aleutian Islands, Andreanof Islands, Adak Island, Chapel Cove (51° 38.5 N, 176° 49.75 W), 24 m.

Type material: Holotype, USNM 1125115 (leg. R.N. Clark and Bob Lauth, 11 July, 1997; scuba 24 m); Paratype, LACM 2007-097.001, Alaska, Aleutian Islands, Andreanof Islands, Adak Island, Bay of Islands, off Green Island (51° 49.023 N, 176° 50.385 W) (leg. H. Chenelot, 9 July, 2007; scuba 16 m) ( AKALE 07-0005).

Additional material: 1, RNC, Aleutian Islands, Petrel Bank, off Semisopochnoi Island (52º 04.112 N, 179º 41.2 E) trawled R/V Sea Storm, 73 m ( NMFS 143- 200401 -126) (leg. R.N. Clark, 7 July, 2004) (images DSC 0124-126). 1, RNC, Aleutian Islands, Stalemate Bank, W of Attu Island (52º 54.50 N, 170º 49.26 E) trawled R/V Dominator, 219 m (leg. R.N. Clark, 2 August, 1997) ( NMFS 23-971-210).

Diagnosis: Large inflated Henricia- like, R to 12 cm; disc small, rays long, broad, relatively soft; ridges of abactinal plates with 8–15 stout spinelets; marginal plates indistinguishable from actinal plates; adambulacral plates with nine or ten spines, grading smaller distally; color in life yellow with irregular maroon mottling.

Description: Large, inflated; disc broad, rays relatively long, broad; Holotype, R = 13.8 cm, r = 24 mm, R:r = 4.8:1 ( Figs. 5,6 & 11). Abactinal and surface ( Fig. 7 ) inflated, thin; plates small, narrower than papular areas, forming ridges in an irregular lattice-like arrangement ( Fig. 8 ) crowned with 8–15 stout, rounded spinelets (to 0.5 mm in height), bearing numerous minute apical thorns; papular areas with one or two papulae and occasionally small plates; madreporite slightly closer to anus than disc edge; small, oval, with irregularly radiating spinose ridges. Marginal plates indistinguishable from abactinal and actinolateral plates, not arranged in discernable linear series; adambulacral plates ( Fig. 9 ) with one small, deep furrow spine, a single large, compressed spine at the edge of the furrow, behind which are one to three similar but somewhat smaller spine(s), followed by series of six to nine still smaller spines. Oral plates ( Fig. 10 ) with five stout, blunt compressed marginal spines, behind which are three smaller cylindrical submarginal spines and a group of six to nine smaller spines on the distal portion of the plate. Color in life ( Fig. 11), yellow with irregular maroon blotches and speckles abactinally.

Distribution: Alaska, Aleutian Islands, Stalemate Bank, W of Attu Island (52º 54.50 N, 170º 49.26 E) (23- 971-210) to Petrel Bank, off Semisopochnoi Island. (52º 04.112 N, 179º 41.2 E) (NMFS 143- 200401 -126), at 16 to 219 m. The distribution of Aleutihenricia federi is not fully understood, it may be an endemic Aleutian species.

Habitat: Subtidal on boulders and bedrock typically covered with the thick, encrusting coralline red algae Clathromorphum nereostratum and sponges, with water temperatures of 4.6 to 5°C.

Etymology: It is with great pleasure that we name this species in honor of Dr. Howard M. Feder, Professor Emeritus, Institute of Marine Science, University of Alaska Fairbanks. During his long career, Dr. Feder has made numerous contributions to our understanding of sea stars. For more than fifty years he unselfishly mentored hundreds of students and marine biologists, passing on his knowledge and passion for the Alaska benthic marine ecosystem.

Remarks: Aleutihenricia federi is a member of a very unique group of Henricia -like Echinasteridae including H. beringiana (D'yakonov, 1950) (Fig. 12) (Bering Sea), H. derjugini (D'yakonov, 1950) ( Fig. 13) (Bering and southern Chukchi Seas), H. reticulata (Hayashi, 1940) ( Japan) and at least one other undescribed species from the western Aleutian Islands, all of which are herein considered members of the genus Aleutihenricia .

Aleutihenricia federi is similar to A. beringiana which occurs at similar depths in the Aleutians, but may be distinguished by 1) coloration, A. beringiana is usually nearly uniformly reddish in color; 2) spinelets of abactinal plates, six to nine in A. beringiana , 8–15 in A. federi ; and 3) Adambulacral plates, which in A. beringiana bear seven or eight spines, compared to 9–12 in A. federi . Aleutihenricia derjugini differs in 1) Uniform white color and 2) 2–4 spinelets on abactinal plates.

Recently Dr. Megumi Strathmann Friday Harbor, Washington (pers. com. March, 2009) examined the type of Henricia sanguinolenta rudis Verrill, 1914 from the Alaskan Arctic, and indicated that it appears to be in this genus also, and that it may even be con-specific with A. beringiana , a re-study of Verrill's original description confirms that it very likely is a member of Aleutihenrica, but it's possible con-specificity with A. beringiana cannot yet be determine. There was no opportunity to examine the type of A. rudis at the time of this study.

Figures

FIGURES 5 – 10. Aleutihenricia federi, Holotype, USNM 1125115. Fig. 5, Ray, abactinal view. Bar = 5.0 cm. Fig. 6, Ray, actinal view. Bar = 5.0 cm. Fig. 7, Close-up, abactinal surface. Bar = 2.0 mm. Fig. 8, Close-up of actino-lateral surface of ray, near the base of the ray, illustrating arrangement of skeletal ossicles. (AD) adambulacrals; (VL) ventral laterals. Bar = 3.0 mm Fig. 9, Close-up of adambulacral region of ray. Bar = 2.0 cm. Fig. 10, Close-up of oral region. Bar = 1 cm.