Echinostrephus molaris (Blainville, 1825)

Arachchige, Gayashan M., Jayakody, Sevvandi, Mooi, Rich & Kroh, Andreas, 2019, An annotated species list of regular echinoids from Sri Lanka with notes on some rarely seen temnopleurids, Zootaxa 4571 (1), pp. 35-57 : 41

Echinostrephus molaris (Blainville, 1825)

Material studied. WUSL/ER/228 (dry, denuded) from Nilwella; WUSL/ER/229 (dry, denuded) from Kalpitiya 2; WUSL/ER/230 (dry, denuded) from Hikkaduwa; WUSL/ER/231 (dry, denuded) from Hiriketiya.

Literature records for Sri Lanka. Döderlein (1888), Herdman et al. (1904), Clark (1915), Schultz (2005), Fernando (2006), Jayakody (2012), Gayashan & Jayakody (2012).

Distribution in Sri Lanka. Northern, southern, and northwestern coasts of Sri Lanka.

Recorded depth range in Sri Lanka. 0.5– 13 m (present study), 13–24 m (previous records) .

Habitat. Mostly in burrows in flat, rocky reef bottoms.

Observed occurrence in this study. Northwestern (Kalpitiya 2) and southern coast (Hikkaduawa, Hiriketiya, and Nilwella) of Sri Lanka.

Remarks. E. molaris can be distinguished from the other echinometrid species recorded in Sri Lanka, Colobocentrotus (Podophora) atratus , Echinometra spp., and Heterocentrotus mamillatus , in having three pore pairs in the pore arcs of the ambulacra and a unique lateral aspect, with the ambitus located high on the test and the aboral side distinctly flattened. E. molaris also has a small, circular test with a flattened, broad aboral side. Unique to the genus, the longest spines project vertically in an aboral tuft, whereas the spines on the ambitus and oral surface are extremely short.

This species was first recorded from Sri Lanka by Döderlein (1888) under the incorrectly formed name “ Echinostrephus molare ”.