Erythrastrea, PICHON, SCHEER & PILLAI IN SCHEER & PILLAI, 1983: 104

Huang, Danwei, Benzoni, Francesca, Fukami, Hironobu, Knowlton, Nancy, Smith, Nathan D. & Budd, Ann F., 2014, Taxonomic classification of the reef coral families Merulinidae, Montastraeidae, and Diploastraeidae (Cnidaria: Anthozoa: Scleractinia), Zoological Journal of the Linnean Society 171 (2), pp. 277-355 : 313-314

GENUS ERYTHRASTREA PICHON, SCHEER & PILLAI IN SCHEER & PILLAI, 1983: 104 ( FIG. 12 )

Type species

Erythrastrea flabellata Pichon, Scheer & Pillai in Scheer & Pillai, 1983: 104, pl. 26: figs 3, 4; original designation, Scheer & Pillai, 1983: 104.

Original description

‘Phaceloid, branches flabellate, compressed, epithecate. Wall thin. Calices meandering, valleys short or long and sinuous, 5 to 10 mm wide, 4 to 5 mm deep. Columella centres distinct, formed of septal fusion, adjacent ones linked by indistinct lamellae. Septa exsert vertically, edges dentate. Costae very conspicuous, extend to the base of the flabellate branches, often linked by transverse ridges.’ ( Scheer & Pillai, 1983: 104).

Subsequent descriptions

Veron, 1986: 595; Sheppard & Sheppard, 1991: 122; Veron, 2000, vol. 3: 98.

Diagnosis

Colonial, with intracalicular budding only. Corallites monomorphic and uniserial; monticules absent. Phaceloid (flabello-meandroid). Calice width medium (4–15 mm), with medium relief (3–6 mm). Septa in three cycles (24– 36 septa). Free septa present but irregular. Septa spaced <six septa per 5 mm. Costosepta equal in relative thickness. Columellae trabecular and spongy (> three threads), <1/4 of calice width, and continuous amongst adjacent corallites. Paliform (uniaxial) and septal (multiaxial) lobes may be present but weak. Epitheca reduced or absent and endotheca abundant (vesicular) ( Fig. 12 ).

Species included

Erythrastrea flabellata Pichon, Scheer & Pillai in Scheer & Pillai, 1983: 104, pl. 26: figs 3, 4 (see Cairns, 1991: 33); lectotype (designated herein): USNM 78094 (dry specimen; Fig. 12 ); paralectotypes (designated herein): ZMTAU NS 6062, 6063 (two dry specimens); type locality: Ghardaqa, Egypt; phylogenetic data: none.

Taxonomic remarks

Erythrastrea Pichon, Scheer & Pillai in Scheer & Pillai, 1983: 104 is a monotypic genus that is known only from the Red Sea. In the original description of its species titled ‘ Erythrastrea flabellata Pichon, Scheer and Pillai , in press’, the authors list as paratypes USNM Wa 75a, b collected from Ghardaqa, Egypt, and NS 6062, 6063 from Tel Aviv, Israel, without any mention of a holotype. Cairns, 1991: 33, explains that the paper cited was never published, stating that ‘Both the generic and species descriptions of Scheer & Pillai (1983) satisfy the requirements of the Code and therefore should be considered as the original descriptions’.

Furthermore, Cairns (1991) lists USNM 78094 as a ‘paratype’, in accordance with the original description. As, to our knowledge, no holotype has been specified, we consider USNM 78094 , NS 6062 and NS 6063 to be a syntype series, from which we designate the USNM specimen that is the basis of our genus diagnosis as lectotype for Erythrastrea flabellata .

Erythrastrea has only been recorded in northern and central Red Sea, and the Gulf of Aden.

Morphological remarks: Erythrastrea has never been collected for molecular work or subcorallite morphology, and only macromorphological characters can be examined here.

Veron (1986: 595) described the genus as similar to Caulastraea based on ‘skeletal structures’, and it is also like Trachyphyllia (and Nemenzophyllia ) because of the flabello-meandroid colony form.

Based on the holotype, we diagnosed Erythrastrea as matching in all but one character each with Caulastraea (discrete instead of uniserial) and Oulophyllia (fused walls instead of phaceloid), suggesting possible placement of the genus within subclade XVII-D/E ( Caulastraea + Oulophyllia + Pectinia + Mycedium ). It does not have the strong septal (multiaxial) lobes seen in Trachyphyllia , and its internal lobes are even weaker than in Caulastraea and Oulophyllia . A fine epitheca may be present – unlike in the latter genera – but the thin walls and phaceloid form are indicative of its close affinity to Caulastraea , as interpreted by Scheer & Pillai (1983: 104).

Figures

Figure 12. Erythrastrea Pichon, Scheer & Pillai in Scheer & Pillai, 1983, is phaceloid or flabello-meandroid, with equally thick costosepta spaced <six septa per 5 mm and abundant (vesicular) endotheca. A, B, Erythrastrea flabellata Pichon, Scheer & Pillai in Scheer & Pillai, 1983, the type and only living species of Erythrastrea; macromorphology, lectotype (designated herein) USNM 78094, Ghardaqa, Egypt.