Echinothrix calamaris (Pallas 1774) FIGURE 6A–C Comments Three color morphotypes are shown in Figure 6, including the black (Fig. 6A), white-spined (Fig. 6B) and banded forms (Fig. 6C). The black and white-spined forms were more common than the banded forms. Debris was observed on the black-spined form (Fig. 6A). Echinothrix calamaris was identified by the presence of an adapical median zone in each interambulacra, which was naked and usually green, and a periproctal membrane and large anal tube possessed of many small, but very conspicuous, white spots. Specimens were observed at Bluff Island, Trio Island and Shek Ngau Chau Island on rocky and coralline substrates in 5–15 meter depths. Occurrence/Distribution Hong Kong, 5–15 m depths. Outside Hong Kong, distributed throughout tropical Indo-West Pacific, but absent from the Arabian Gulf, Pakistan, W. India and Sri Lanka, 0–90 m (following A.M. Clark & Liao 1995).

Published as part of Yiu, Sam King Fung & Mah, Christopher L., 2024, New Ecological Observations and Occurrence for Asteroidea and Echinoidea in Hong Kong, pp. 1-69 in Zootaxa 5526 (1) on pages 15-16, DOI: 10.11646/zootaxa.5526.1.1, http://zenodo.org/record/14021526