Skeletal Modification by a Polychaete Annelid in Some Scleractinian Corals

Abstract

The presence in some faviid corals of deep intercalicular grooves and subphaceloid corallites united by a system of tubercules and epitheca-like tubes (groove-and-tube structure) has been the subject of considerable controversy and speculation in reef-coral taxonomy since the feature was first described by Milne Edwards and Haime (1848) in their diagnosis of the genus Phymastrea. During the past ten years, the present authors have been studying and collecting reef corals at Guam and at other Micronesian islands and have never observed features which could be related to such a unique mode of corallite junction. The first encounter with this structural feature came while the senior author was a member of a joint Sino-American team conducting a biological survey of the coral reefs of southern Taiwan. During this survey the coral wall junction was hastily noted while cleaning and packing coral specimens, but it was not until later when the coral collection was being studied in detail, that the significance and possible association of the coral and some other organism was realized. This has been a problem noted by several others who had studied similar structures (Quelch, 1886; Rosen, 1968). We thus found ourselves in the same situation as previous workers studying this structural feature, without preserved coralla with intact polyps and without the opportunity to observe in situ specimens known to possess the structure. Our field data and specimen notes indicate that this common and conspicuous coral, here placed with Favia valenciennesii (Milne Edwards and Haime, 1848), was collected and observed in a wide range of biotopes along the Southern Taiwan coast (Jones et al., 1972).

Contribution No. 85, University of Guam Marine Laboratory.