SEA STARS OF THE PACIFIC NORTHWEST

Class Asteroidea

Order Spinulosida

Family Echinasteridae

ARMPIT BLOOD STAR

Henricia sp. A (undescribed species)

Identification:

5 slender arms with small central disc. Aboral surface coarse. Orange to red or brown with grey or pinkish patches at the base of the rays and sometimes extending onto the disc. To 26 cm (7.9 in) across.

Range:

Aleutian Islands to Oregon; intertidal to at least 20 m (66 ft).

An ARMPIT BLOOD STAR crawls over a bed of fluted bryozoans in Porlier Pass, BC.

An ARMPIT BLOOD STAR on a rocky reef near Kunechin Point, Sechelt Inlet, BC. To the right is an unusual 4-armed BLOOD STAR.

2 - 2

Notes:

Conspicuous both intertidally and subtidally. Feeds primarily on sponges including the ORANGE FINGER SPONGE Isodictya rigida. May also use water currents generated by sponges to capture food in mucous secretions of the tube-feet.

From Jewett et al, 2015, "A Field Guide to Sea Stars of the Aleutian Islands": “Henricia sp. A is a “forgotten” species, recently rediscovered by Dr. Megumi Strathmann, and its redescription is presently part of the study of the Henricia leviuscula complex by Strathmann and Eernisse.”

On-going research by Doug Eernisse, Megumi Strathmann and Richard Strathmann has shown that many similar-looking "blood" stars are in fact morphologically different when the ultra-fine details of plates and spines are compared using Scanning Electron Microscopy. Several new species await formal description.