Australogyra, VERON & PICHON, 1982: 138

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 : 298-299

GENUS AUSTRALOGYRA VERON & PICHON, 1982: 138 ( FIG. 5 )

Type species

Platygyra zelli Veron, Pichon & Wijsman-Best, 1977: 110 , figs 214–222, 459; original designation, Veron & Pichon, 1982: 138.

Original description

‘This species was described in Part II, p. 110 as Platygyra zelli , where it was noted that ‘the ramose growth form of this species, combined with the normal lack of a columella, separates it from all other Platygyra and makes its generic affinities obscure... As this is a monospecific genus, its characters are those of zelli . [“Colonies are up to 25 cm high and have main branches 1.5–3 cm in diameter. Actively growing branch ends are composed of intricate arrays of thecae and elongated septa reminiscent of branch tips of Hydnophora rigida on a larger scale. Dead skeleton forms the base of most colonies. The valleys are short and usually monocentric. The walls are thick (2– 4 mm) especially towards the base of colonies where skeletal parts are heavily calcified. Valleys are usually shallow with smooth blister-like floors. There is usually no sign of a columella, although elongated, recurved septal dentations are occasionally found and occasionally these form a distinct columella. The septa are similar to those of P. daedalea and P. lamellina . They are dentate and have fine granulations on their sides. Some dentations are twisted to form tiny horizontal plates fringed with granulations, presumably sclerodermites.” ( Veron et al., 1977: 110)]’ ( Veron & Pichon, 1982: 138).

Subsequent descriptions

Veron, 1986: 494; Veron, 2000, vol. 3: 194.

Diagnosis

Colonial, with intracalicular budding only. Corallites monomorphic, uniserial, and ramose; monticules absent. Walls fused. Calice width medium (4–15 mm), with medium relief (3–6 mm). Costosepta confluent. Septa in <three cycles (<24 septa). Free septa present but irregular. Septa spaced six to 11 septa per 5 mm. Costosepta equal in relative thickness. Columellae trabecular but compact (one to three threads) or absent, <1/4 of calice width, and continuous amongst adjacent corallites. Paliform (uniaxial) lobes absent. Epitheca well developed and endotheca low−moderate (tabular) ( Fig. 5A, D ).

Tooth base at midcalice circular. Tooth tip at midcalice irregular; tip orientation perpendicular to septum. Tooth height low (<0.3 mm) and tooth spacing medium (0.3– 1 mm), with> six teeth per septum. Granules aligned on septal face, perpendicular to septal margin; weak (rounded). Interarea palisade ( Fig. 5B, E ).

Walls formed by dominant trabeculotheca and partial septotheca; abortive septa absent. Thickening deposits fibrous. Costa centre clusters weak; <0.3 mm between clusters; medial lines weak. Septum centre clusters weak; <0.3 mm between clusters; medial lines strong. Transverse crosses absent. Columella centres aligned ( Fig. 5C, F ).

Species included

Australogyra zelli ( Veron, Pichon & Wijsman-Best, 1977: 110, figs 214–222, 459); holotype: NHMUK 1977.1 .1.4 (dry specimen; Fig. 5A ); paratype: MTQ G59708 (dry specimen; Fig. 5D ); type locality: Pioneer Bay , Orpheus Island, Palm Islands, Australia, 3 m depth; phylogenetic data: morphology only .

Taxonomic remarks

Australogyra Veron & Pichon, 1982: 138 , is a monotypic genus sister to Platygyra on the morphological phy- logeny. This relationship is reflected in its taxonomic history, as Australogyra zelli was initially described as a Platygyra species , and only put in its own genus later.

Australogyra is only present in the Great Barrier Reef and Coral Sea of Australia, Papua New Guinea, and south Sulawesi ( Hoeksema & van Ofwegen, 2004).

Morphological remarks

As suggested by the original description ( Veron & Pichon, 1982: 138), it shares almost all characters with Platygyra , differing only in having a compact or no columella. Our character trace suggests that this state is plesiomorphic, and hence no apomorphies are yet present for the genus. The ramose growth form also distinguishes it from Platygyra . Molecular data would further clarify its phylogenetic placement.

Figures

Figure 5. Australogyra Veron & Pichon, 1982, is ramose and has uniserial corallites with few centres, fused walls, septa in <three cycles (<24 septa), equally thick costosepta and compact columellae. Septal teeth are low (<0.3 mm) with medium spacing (0.3–1 mm); weak (rounded) granules aligned on septal face. Walls formed by dominant trabeculotheca and partial septotheca, with strong septal medial lines and aligned columella centres. A–F, Australogyra zelli (Veron, Pichon & Wijsman-Best, 1977), the type and only living species of Australogyra; macromorphology, holotype NHMUK 1977.1.1.4, Orpheus Island, Australia (A; photo by H. Taylor), and paratype MTQ G59708, Eclipse Island, Australia (D); micromorphology (scanning electron microscopy; B, E) and microstructure (transverse thin section; C, F), hypotype USNM 76312, the Philippines.