Archaster typicus Müller & Troschel 1840

Yiu, Sam King Fung & Mah, Christopher L., 2024, New Ecological Observations and Occurrence for Asteroidea and Echinoidea in Hong Kong, Zootaxa 5526 (1), pp. 1-69 : 35

Archaster typicus Müller & Troschel 1840

FIGURE 25

Comments

The Archasteridae is a monotypic family including the single genus Archaster which in turn, includes three species, two present in the Indian Ocean and a third, the widely occurring Archaster typicus in the tropical central Pacific. This species is present on sandy, unconsolidated bottoms where they apparently evert their stomachs to feed. Marsh & Fromont (2020) presented a brief summary of the biology of this species. Perhaps the best known aspect of Archaster typicus is their reproductive behavior which involves the, unusual in echinoderms, physical superposition of males on females, known as pseudocopulation (e.g. Run et al. 1988). An unpublished Masters thesis by Wong Tim Lung (2016) notes a population explosion of this species recorded by surveys between 2012 and 2014, which may have affected bivalve populations suggesting significant impact on community structure.

Archaster typicus is a familiar species, occurring in great abundance and occurring in shallow-water depths, leading to intensive fishing for tourist shops, holiday ornaments, and the pet trade has led to localized disappearance of this species as noted by Bos et al. (2008).

Occurrence/Distribution

Hong Kong, Sharp Island east, 3m.

Outside Hong Kong. Widely occurring throughout the tropical Pacific and adjoining regions, Bay of Bengal , northern Indian Ocean , Southern Japan, Philippines, Papua New Guinea, Malaysia, Indonesia, Northeastern Australian coast, South Pacific, New Caledonia. 0–3 m. (after Marsh & Fromont 2020).

Figures

FIGURE 25. Archaster typicus. In situ observation. Photographer: Sam King Fung Yiu.