Microcyphus rousseaui L. Agassiz in L. Agassiz & Desor, 1846

Filander, Zoleka, Samyn, Yves & Griffiths, Charles, 2019, Four notable additions to the South African echinoid fauna (Echinodermata, Echinoidea), ZooKeys 831, pp. 71-80 : 74

Microcyphus rousseaui L. Agassiz in L. Agassiz & Desor, 1846 Fig. 1E, F

Microcyphus rousseaui L. Agassiz & Desor, 1846: 358, pl. 15.10; Mortensen 1904: 98; Mortensen 1943: 155-159, pl. XIII, figs 18-25, pl. XLVII, figs 18-20, 23-24 [description and synonymy]; Clark and Rowe 1971: 140, 156; Samyn and Vanden Berghe 2000: 6, 13, pl. 1E [distribution]; Schultz 2010: 148, fig. 273 [distribution].

Identification.

Test small sized (test diameter = 20 mm), low, hemispherical. Ambulacral pore-pairs arranged in double series, outer series formed by pore-pair of median component, and the inner series by pore-pairs of the upper and lower component of each compound ambulacra plate. Interambulacra partially tuberculated, with sparsely and irregularly arranged same-sized tubercles. Naked part of interambulacra broad and conspicuous. Apical system with apical plates densely covered by tubercles, ocular plates exsert. Periproct covered with numerous plates. Spines of uniform size, reddish-brown with white tips; naked median areas brownish-red, becoming lighter to centre. Denuded test light brown, with darker tuber-covered parts.

Material examined.

SAMC.A090124: two specimens collected by SCUBA diving off Leadsman Shoal, Sodwana Bay; SAMC.A090125: one specimen collected by SCUBA diving off Redsands Reef, Sodwana Bay; RBINS I.G. 33199/Ech.132: one specimen collected by SCUBA diving off the 7-Mile Reef, Sodwana Bay. All samples were collected through the Belgian Global Taxonomy Initiative in January 2016, at a 10-23.9 m depth range. All specimens, except for those belonging to sample SAMC.A090124, are complete with spines and preserved in 70 % ethanol.

Habitat.

Reef habitat.

Global distribution.

Western Indian Ocean: Red Sea, East African coast southwards to Mozambique ( Mortensen 1943; Clark and Rowe 1971; Samyn and Vanden Berghe 2001; Schultz 2010)

South African distribution.

East coast of South Africa, off Sodwana Bay; off Leadsman Shoal (27.8737°S, 32.6036°E), Redsands Reef (27.7384°S, 32.6298°E), and 7-Mile Reef (27.4515°S, 32.7118°E).

Remarks.

Closely resembles Microcyphus maculatus L. Agassiz in L. Agassiz and Desor 1846 from which it differs in the coloration and apical system. Microcyphus rousseaui has reddish brown spines and apical plates bearing more than three tubercles, whereas M. maculata has light green spines and an apical system bearing fewer than three tubercles per plate ( Mortensen 1943).

Microcyphus rousseaui differs from M. rousseaui purpuratus Mortensen, 1942 in coloration of the spines, the sub-species having purple spines with distinctive white bands ( Mortensen 1942).

This is the first South African record of this species and represents a range extension southwards from Mozambique, the southernmost-recorded location. It is also the first record of the genus in the region.