Family MACROPORIDAE Uttley, 1949

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Introduction

The family Macroporidae was introduced by Uttley (1949), following a suggestion by Canu & Bassler (1920), that the genus Macropora required a separate family from the Microporidae. Species of Macropora are characterised by their large zooids, which have a convex frontal shield formed by a finely porous cryptocyst covered by a thick frontal membrane. Colonies may be bilaminar or unilaminar, erect or encrusting, and some colonies are fenestrate. There are no obvious opesiules, and the opesia and the uncalcified primary orifice with the operculum are completely coterminous. The operculum itself may be calcified (Brown 1952). Polymorphic zooids with modified opercula occur in some species, but avicularia are absent. The ovicell is a gonozooid which rests distally upon either an autozooid or a kenozooid; it is very large, sometimes larger than the autozooid, and is closed by the operculum. A detailed study of the structure of zooids of Macropora levinseni Brown 1952 by Banta, Gray & Gordon (1997) has revealed a number of characters which are unusual. The calcareous operculum is a cryptocyst, coinciding almost exactly with the aperture. Associated with this is a method for raising zooid internal pressure for lophophore protrusion, involving numerous parietal muscle bundles which pass through small pores in the frontal cryptocyst.

Macropora centralis, the type species, and several other similar forms, occurred in the Australian Tertiary (MacGillivray 1895). There is only one Recent species in Australia, on the Norfolk Ridge, Marcopora carlosi (Gordon & Taylor, 2008). Multiple species, including Macropora grandis, are present today in New Zealand (Gordon 1984, López de la Cuadra & García-Gómez 1997, Gordon & Taylor, 2008).

Diagnosis

Colony encrusting or erect. Zooids with convex porous frontal cryptocyst, with numerous small opesiular pores (analogous to an ascophoran frontal with pseudopores). Opesia broadly D-shaped, closed by coterminous overlying calcareous operculum. A dimorphic zooid with a more elaborate operculum is assumed to be an avicularian homologue. Brooding zooids with inflated prominent ovicell recumbent on distal zooid, kenozooid, or on the substratum.

General References

Banta, W.C., Gray, N., & Gordon, D.P. 1997. A cryptocystal operculum and a new method of lophophore protrusion in the cheilostome bryozoan Macropora levinseni. Invertebrate Biology 116(2): 161-170

Brown, D.A. 1952. The Tertiary cheilostomatous Polyzoa of New Zealand. London : Trustees of the British Museum (Natural History) 405 pp.

Canu, F., & Bassler, R.S. 1920. North American early Tertiary Bryozoa. United States National Museum Bulletin 106: 1-879

Gordon, D.P. 1984. The marine fauna of New Zealand: Bryozoa: Gymnolaemata from the Kermadec Ridge. New Zealand Oceanographic Institute Memoir 91: 1-198

Gordon, D.P. & Taylor, P.D. 2008. Systematics of the bryozoan genus Macropora (Cheilostomata). Zoological Journal of the Linnean Society Zoological Journal of the Linnean Society 153: 115-146 [121-122]

López de la Cuadra, Carlos-Maria, & García-Gómez, José-Carlos 1997. Studies on Recent Macroporidae (Bryozoa, Cheilostomatida), with new taxa and ontogeny of the ovicells. Journal of Zoology, London 242: 605-621

Macgillivray, P.H. 1895. A monograph of the Tertiary Polyzoa of Victoria. Transactions of the Royal Society of Victoria ns 4: 1-166

Uttley, G.H. 1949. The Recent and Tertiary Polyzoa (Bryozoa) in the collection of the Canterbury Museum. Part 1. Records of the Canterbury Museum 5(4): 167-192

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