Echinothrix calamaris (Pallas, 1774)

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 : 39-40

Echinothrix calamaris (Pallas, 1774)

Material studied. WUSL/ER/210 (dry, with spines) from Nilwella; WUSL/ER/211 (dry, denuded) from Polhena.

Literature records for Sri Lanka. Jayakody (2012).

Distribution in Sri Lanka. Southern coast of Sri Lanka.

Recorded depth range in Sri Lanka. 1–2 m (present study).

Habitat. Reef flats and tide pools.

Observed occurrence in this study. Southern coast (Hiriketiya, Nilwella, and Polhena) of Sri Lanka.

Remarks. The test of E. calamaris can be distinguished from that of E. diadema by having naked adapical medial zones in the interambulacra, conspicuously inflated aboral ambulacra, no enlarged ambulacral tubercles at the ambitus and small auricles with low connecting ridges in the interambulacra. In life, E. calamaris is easily distinguished from E. diadema in having banded, usually pale or white primary spines, and concentrations of gold or light brown, poison-gland bearing spines in the ambulacra that are much shorter and more sharply pointed than the interambulacral primaries. See Coppard & Campbell (2006) for an in-depth discussion of the test features distinguishing the two species.

This species was recently added to the Sri Lankan echinoid faunal list by Jayakody (2012). Our study confirms

the presence of E. calamaris in Sri Lanka. E. calamaris is widely distributed from the western Indian Ocean ( Samyn 2003) to the eastern Indian Ocean ( Putchakarn & Sonchaeng 2004; Sastry 2007) and beyond (see Clark & Rowe 1971 for a summary).