Lamarck, 1801, p. 371
Madrepora rotulosa Ellis and Solander, 1786, p. 166, pl. 55: figs 1–3; Original Designation Lamarck, 1801, p. 371
Type Specimen: Holotype; GLAHM 104014; Verified; Dry Preserved
Type Locality: Unknown (Recent)
Colonial, with extracalicular budding; no intracalicular budding. Corallites monomorphic and discrete (1–3 centers); monticules absent. Coenosteum costate, moderate amount (< corallite diameter). Calice width medium (4–15 mm), with medium relief (3–6 mm). Costosepta not confluent. Septa in 3 cycles (24–36 septa). Free septa present, may be regular or irregular. Septa spaced 6–11 septa per 5 mm. Costosepta unequal in relative thickness. Columellae trabecular and spongy (> 3 threads), < 1/4 of calice width. Paliform (uniaxial) lobes well developed. Epitheca well developed and endotheca low-moderate (tabular). Tooth base at mid-calice circular. Tooth tip at mid-calice irregular; tip orientation perpendicular to septum. Tooth height low to medium (≤ 0.6 mm) and tooth spacing medium (0.3–1 mm), with > 6 teeth per septum. Granules scattered on septal face; irregular in shape. Interarea palisade. Walls formed by dominant paratheca and partial septotheca; abortive septa weak. Thickening deposits fibrous. Costa center clusters weak; 0.3–0.6 mm between clusters; medial lines weak. Septum center clusters weak; 0.3–0.5 mm between clusters; medial lines weak. Transverse crosses absent. Columella centers clustered.
'Polypier pierreux, crustacé, en masse glomérulée ou en expansion lobée subfoliacée, ayant sa surface supérieure parsemée d'étoiles lamelleuses et sessiles.' (Lamarck, 1801: 371)
Astrea rotulosa has not been been placed on the molecular phylogeny, but it is most similar to A. devantieri. Each macromorphological character examined is the same state for both species, except for the more compact columellae in the type specimen of the former. Spongy columellae can however be found in Favia rotulosa specimens studied by Ehrenberg, 1834: 319 (ZMB Cni 739II) and Wijsman-Best, 1974: 258, pl. 4, fig. 4 (ZMA Coel. 8888), collected from the Red Sea and Indonesia respectively. Consequently, we hypothesize that Astrea devantieri, thus far recorded only from Socotra (type locality), Madagascar and Mayotte (Veron, 2002; Benzoni et al., 2011), is a sister species to Astrea rotulosa. While we have limited data to place all Astrea spp. on the tree concomitantly, we infer that Astrea annuligera Milne Edwards and Haime, 1849, vol. 12: 103 and Astrea curta Dana, 1846: 209 are closely related based on morphology. As this genus is represented only by A. curta on the molecular tree, no synapomorphies are diagnosed—absence of intracalicular budding and weak abortive septa are autapomorphies. On the morphological phylogeny, however, these features are synapomorphies. Goniastrea australensis has been recovered as the sister taxon to Astrea curta + Favites russelli in one instance (Huang et al., 2011; but see Arrigoni et al., 2012). Morphologically, G. australensis is very distinct from Astrea as it lacks extracalicular budding, has uniserial corallites, fused walls, confluent costosepta, evenly thick costosepta and narrow distance between septum center clusters (< 0.3 mm). Most of these characters, except uniserial corallites and confluent costosepta, and many others, also separate the Goniastrea proper from this genus. Favites russelli is the sister taxon to Astrea on the molecular tree, but it buds intracalicularly and does not have abortive septa to be considered in the latter genus.
Astrea Lamarck, 1801: 371 is the oldest genus in Merulinidae, and was first established as part of a class of animals possessing polyps, Polypes Lamarck, 1801: 357. Sixteen of the genera were in the subdivision described as 'Polypier solide, entièrement pierreux et calcaire' (Lamarck, 1801: 369)—having polyps that are solid, completely stony and calcareous—resulting in the redistribution of species of the only stony coral genus prior to 1801, Madrepora Linnaeus, 1758: 793 (see Vaughan and Wells, 1943: 2–3). Subsequent works, including Lamarck, 1816: 257, de Blainville, 1830: 332, and Dana, 1846: 200 attributed as many as 61 species to Astrea before the establishment of additional genera by Milne Edwards and Haime, 1848, vol. 27: 494–496. Astrea was then split into several genera, and also assigned Astrea argus Lamarck, 1816: 259 as the type species (Milne Edwards and Haime, 1848, vol. 27: 494), instead of Astrea rotulosa (Ellis and Solander 1786: 166). Curiously, 'Astrea rotulosa et ananas, Lamarck' was ascribed to be the type of Parastrea Milne Edwards and Haime, 1848, vol. 27: 495, which is a synonym of Dichocoenia Milne Edwards and Haime, 1848, vol. 27: 469 (see Gregory, 1895: 270). The genus was synonymized by Matthai, 1914: 84, 115, as Favia after recognizing types of both Madrepora rotulosa Ellis and Solander, 1786: 166 and Astrea rotulosa Lamarck, 1801: 371 to be part of Favia. Matthai, 1914: 115 also compared Ellis and Solander's, 1786: 166 type of Madrepora rotulosa, with Orbicella annularis, a Caribbean species. This specimen, not Astrea rotulosa Lamarck, 1801: 371 or Favia rotulosa Ehrenberg, 1834: 319, is clearly the original designated type of Astrea. However, this specimen bears the closest resemblance to Plesiastrea devantieri Veron, 2000, vol. 3: 228, especially given their well-developed paliform lobes that are absent among the Orbicella species defined in this study. This genus was thus revived to include Madrepora rotulosa, Plesiastrea devantieri, as well as species that have been found to be closely related genetically and morphologically (Huang et al., 2014).
Astrea is widely distributed on reefs of the Indo-Pacific, recorded throughout most of French Polynesia and Pitcairn Islands in the southern hemisphere (Glynn et al., 2007), but absent eastwards from Hawai'i in the north.
- Indian Ocean; Recent
- Western Pacific; Recent
- Central Pacific; Recent
This page has been in preparation since 18-Jul-2010 20:20
This version was contributed by Danwei Huang on 05-Feb-2014 19:20.
Page authors are: Ann Budd Danwei Huang. Please contact the editor if you would like to contribute to the diagnosis of this taxon.
The editor is: Ann Budd