Echinometra mathaei ( Blainville 1825 )

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 : 16-17

Echinometra mathaei ( Blainville 1825)

FIGURE 7

Comments

A familiar urchin species which is heavily documented elsewhere and is only briefly touched upon here, observed from Tsim Chau, Long Ke and Tung Ping Chau at 2–10 m in rocky and coral habitats. This species has been heavily studied in a wide range of topics, including a model for phylogeography (e.g. Bronstein & Loya 2013; McCartney et al. 2000) and ecology (e.g. McClanahan & Kurtis 1991; Hiratsuka & Uehara 2007). This species is known for creating and inhabiting bored concavities in rocky substrates (e.g. McClanahan & Kurtis 1991). It feeds on plants and encrusting organisms, especially sponges ( Schultz 2015).

Although historically recorded as a wide-ranging Indo-West Pacific species, as outlined in Clark & Liao (1995), recent phylogenetic work (e.g. Bronstein & Loya 2013; McCartney et al. 2000) suggests multiple lineage within what had previously been considered a single wide-ranging species, notably that lineages from the Indian Ocean are separate from those in the tropical Pacific ( Bronstein & Loya 2013).

This species is differentiated from the similarly elongated Parasalenia by having a much larger apical system with characteristically pointed genital plates and more distinct white rings around the spines.

Occurrence/Distribution

Hong Kong, 2–10.0 m.

Outside Hong Kong, Southern China, throughout the Indo-Pacific, Hawaii, Guam, Bali, Okinawa, Great Barrier Reef ( Australia). 0–30 m [ E. mathaei in the Indian Ocean is a different taxon from the Pacific, following Bronstein & Loya 2013; McCartney et al. 2000 and in part Clark & Liao (1995)].

Figures

FIGURE 7. Echinometra mathaei. In situ observation. Photographer: Sam King Fung Yiu.