Physophyllia, DUNCAN, 1884: 118

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 : 335-336

GENUS PHYSOPHYLLIA DUNCAN, 1884: 118 ( FIG. 23 )

Type species

Physophyllia ayleni Wells, 1935: 342 , pl. 13, pl. 14: figs 1–3 (non Pectinia ayleni sensu Veron, 2000 , vol. 2: 352, figs 1–3); subsequent designation, Wells, 1935: 340.

Original description

‘Colony large, spreading, pedunculate, foliaceous, folia united and presenting faint broad ridges, which are crossed by septocostae. Corallites low, wide apart, arranged more or less in concentric circles. Calices distant, large, sunken, deep, elongate, forming series of 2 to 4, or circular. Fossa large and deep. Columella small, trabeculate. Septa large, exsert, spinulose, especially near the axis, unequal, wide apart; ending in septocostae which are confluent with those of the calices on either side, and some of which pass over broad ridges radially. Intercalicular surface large, gibbous or ridged, formed of convex vesicular endotheca; this endotheca fills up the interseptal loculi also, and is greatly developed. Calices on one side of the colony only. Common wall inferior, costulate to the base. Costae distinct, spinulose. No epitheca. Fissiparity occurs, and also gemmation.’ ( Duncan, 1884: 118).

Subsequent descriptions

Delage & Hérouard, 1901: 631, 632; Wells, 1935: 340; Yabe et al., 1936: 52; Vaughan & Wells, 1943: 198; discontinuous amongst adjacent corallites (lamellar linkage). Paliform (uniaxial) lobes weak or moderate. Epitheca absent and endotheca abundant (vesicular) ( Fig. 23 ).

Species included

Physophyllia ayleni Wells, 1935: 342 , pl. 13, pl. 14: figs 1–3; holotype: NHMUK 1862.7 .16.46 (dry specimen; Fig. 23A ); paratypes: NHMUK 1892.10 .17.97, 1893.9.1.185, 1893.9.1.186, 1893.9.1.187, 1893.9.1.188 ( Fig. 23B ), 1893.9.1.189, 1893.9.1.190 (seven dry specimens); type locality: Japan; phylogenetic data: none.

Taxonomic remarks

This is a monotypic genus with Physophyllia ayleni as its sole member. The species was placed in Pectinia by Veron (2000, vol. 2: 352) based on his collection, presumably shown in figs 1–3. These are however distinct from the type material studied by Wells (1935: 342) and thus have been described as Pectinia crassa Ditlev, 2003: 204 , figs 13–15, with material from Sabah. The distribution of Physophyllia remains as defined by the type material of Physophyllia ayleni – holotype from Japan and paratypes from Macclesfield Bank in the South China Sea. Subsequent studies appear to have expanded this range to the Maldives ( Pillai & Scheer, 1976: 69, pl. 31: fig. 1; Scheer, 1984) and western Australia ( Veron, 1993: 237), but only the former could be verified as a likely candidate for the species.

Alloiteau, 1952: 632; Wells, 1956: F419; Nemenzo, 1971: 176; Wood, 1983: 200,201; Veron, 1986: 592; Chevalier & Beauvais, 1987: 726.

Diagnosis

Colonial, with intracalicular budding only. Corallites polymorphic and organically united; monticules absent. Coenosteum costate, extensive amount (≥ corallite diameter). Calice width medium (4–15 mm), with medium relief (3–6 mm). Costosepta confluent. Septa in three cycles (24–36 septa). Free septa present but irregular. Septa spaced <six septa per 5 mm. Costosepta unequal in relative thickness. Columellae trabecular and spongy (> three threads), <1/4 of calice width, and Morphological remarks

Based on an examination of the type material of Physophyllia ayleni , the genus shares all macromorphological characters studied here with Pectinia and Mycedium . Note that quantitative measurements were based on peripheral corallites as some structures of the central corallite, such as the columella, may be extremely large in comparison.

Although we recognize Physophyllia as distinct from Pectinia and Mycedium , subcorallite morphology and/ or DNA sequence data will reveal the accuracy of this interpretation. The latter two genera are indistinguishable for all of the characters used for the present analysis, but they arguably span a wide range of morphologies not coded into phylogenetic data. The coenosteum of Physophyllia is made up of large ridges filled with vesicular endotheca, and does not form upwardly projecting laminae seen in most Pectinia species. Its corallites are also not distinctly inclined towards the periphery of the colony, a clear distinction from Mycedium . If Physophyllia is indeed separable from either of these genera based on the same molecular markers as employed here, it would probably be recovered outside of the Pectinia + Mycedium clade, and subcorallite disparities could be expected.

Figures

Figure 23. Physophyllia Duncan, 1884, has organically united and polymorphic corallites, extensive coenosteum (≥ corallite diameter), septa spaced <six septa per 5 mm, spongy columellae, and abundant (vesicular) endotheca. A, B, Physophyllia ayleni Wells, 1935, the type and only living species of Physophyllia; macromorphology, holotype NHMUK 1862.7.16.46, Japan (A; photo by H. Taylor), and paratype NHMUK 1893.9.1.188, Macclesfield Bank, South China Sea (B).