Microcyphus ceylanicus Mortensen, 1942

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 : 42

Microcyphus ceylanicus Mortensen, 1942

Figure 2

Material studied. WUSL/ER/87 (dry, denuded) from Hiriketiya; WUSL/ER/234 (wet, with spines) from Hiriketiya; WUSL/ER/235 (dry, denuded) from Dickwella.

Literature records for Sri Lanka. Mortensen (1942, 1943a), Price & Rowe (1996), Fernando (2006), Jayakody (2012).

Distribution in Sri Lanka. Southern coast of Sri Lanka.

Recorded depth range in Sri Lanka. 1–5 m (previous records).

Habitat. Coral reefs ( Price & Rowe 1996).

Observed occurrence in this study. Southern coast (Hiriketiya and Dickwella), on shore. Both of these collection sites were dominated by seagrass beds at shallow depths.

Remarks. Here, for the first time, we provide photographs of test surface details on this rarely seen temnopleurid ( Fig. 2 ). Its test has never been figured in detail, and Mortensen (1943a) included only a photograph in lateral view, plus drawings of the apical system, ambulacral compounding, and some pedicellariae. M. ceylanicus is restricted to Sri Lanka and the Andaman Islands, and can be distinguished from other Sri Lankan regular echinoids by its light olive-green test. The test has naked interambulacral areas, each of which has a dark zigzag line along the medial sutures ( Fig. 2 ). The spines are banded with red, brown, and white. This species is characterized by its sharply delimited naked areas in both the interambulacra and ambulacra ( Mortensen 1942).

Döderlein (1888) misidentified this species as M. maculatus , an error that was rectified by Mortensen (1943a). The type specimen, collected from Sri Lanka, is housed at the Zoologische Staatssammlung München (The Bavarian State Collection of Zoology, Munich).

Figures

FIGURE 2. Test features of Microcyphus ceylanicus (WUSL/ER/87): A, aboral view; B, oral view; C, lateral view; D, ambital ambulacrum; E, ambital interambulacrum; F, oblique view through peristome showing an auricle D and E whitened with ammonium chloride.