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The presence of a small colony of Synastrea bellula (d’Orbigny, 1850) in Berriasian beds of the pelagic Maiolica in the Venetian Prealps (NE Italy) provides a key for interpreting the palaeobathymetry of the formation on the Trento Plateau. This pennular scleractinian belongs to a zooxanthellate group whose fossil and modern representatives are characterized by an outstanding specialization in colonizing deeper parts of the marine photic zone (mesophotic zone). The coral grew on the shell of an inferred ammonoid affected by intense microbial erosion. The conch was encrusted first by bryozoans and later by the coral, which immurated a microserpulid, designated as Turriserpula coralliophila gen. et sp. nov. Applying the sclerochronology method, a life duration of the stony coral of at least twelve years is inferred.

Holocene Madrepora-Lophelia subfossil frames recovered at ca. 690 m from deep-water coral grounds south of Malta (Strait of Sicily, Central Mediterranean Sea) were found to entrap shells of cnidarian predatory gastropods such as Babelomurex sentix , “ Coralliophila ” squamosa (morphotype ruderatus ) and architectonicids. This finding documents the capability of deep-water coral reefs to serve as taphonomic traps eventually promoting the preservation of rare components of their original biota.

Habitat formation by foundation species is a major ecological force affecting community structure in numerous systems. On the upper continental slope of the Gulf of Mexico, the cold-water scleractinian coral Lophelia pertusa creates complex habitat on cold seep-associated carbonates. In this study, the communities associated with the cold-water coral L. pertusa are described from the Gulf of Mexico for the first time. A total of 68 taxa was identified in close association with the coral framework. Three species with specific relationships to L. pertusa were identified: Eunice sp., a polychaete which may facilitate colony formation in L. pertusa ; Coralliophila sp., a species of corallivorous gastropod ; and Stenopus sp., a decapod crustacean which may act in a cleaner shrimp role in these habitats. Similarity among coral-associated communities was best explained by similarity in depth of collection and the proportion of live coral in the collections. These variables were somewhat confounded with location as the sites to the east were both shallower and contained higher proportions of live coral; however, distance between collections per se was not as significant in the analyses. The coral-associated communities also showed a low degree of similarity to communities inhabiting vestimentiferan tubeworm aggregations that occur nearby at the same sites. The increased habitat heterogeneity in the coral structure, differences in the niches constructed by the two foundation species, and different direct interspecific interactions between foundation species and members of the associated community contributed to the presence of dissimilar communities in these two biogenic habitats.

Fidelity of death assemblages to live shelly faunas is one of the major palaeontological questions, but quantitative data are scarce and most case studies on this topic have been performed in non-reef sediments. Therefore we studied diVerent types of subtidal reef-associated hard substrata (reef flats, reef slopes, coral carpets, coral patches, rock grounds), each with diVerent coral associations, in order to determine the agreement of assemblages of living and dead shell-bearing molluscs. A total area of 340.5 m2 was investigated and 2846 individuals were counted at 68 sample localities ranging from shallow subtidal to 40 m water depth. Most taxa found dead in the study area were also found live and vice versa; diVerences in this respect can be related to quantitatively unimportant taxa. However, strong diVerences exist in the proportion of living and dead fauna, dominant taxa, and molluscan distribution patterns. The ratio of live to dead molluscs is high. Living molluscs are strongly dominated by taxa with distinct relations to corals, mainly Pedum, Coralliophila and Tridacna, and the encrusting gastropod Dendropoma. Five distinct groups of living molluscs can be diVerentiated and related to specific hard substrata, which are characterized by distinct molluscan life habits. In contrast, the death assemblages are always strongly dominated by encrusting bivalves, mainly Chamoidea and Spondylidae, and cerithiid gastropods in varying dominances. Correspondingly there is no significant correlation of the total abundance of living and dead molluscs and their overall similarity is only 6%. Similarity between living and dead faunas is above 50% at only 12 of the 68 sample locations, and at 17 sample locations significant correlations of living and dead molluscs were recognized. These correlations are mainly based on Chamoidea, which dominate both the living and dead fauna, on rock grounds. Therefore rock grounds are the only bottom type with consistent correlations and similarities of living and dead molluscs. The observed bias is due to the close relationship of molluscan life habits and post-mortem history of shells. Molluscs that live permanently attached to or within living corals (mostly bivalves and encrusting Dendropoma) can easily be overgrown after death by the large amounts of living substrata available. Rapid transport of dead shells into surrounding sediments or into crevices within corals is typical of gastropods that feed on corals. Molluscs that colonize dead surfaces preferentially accumulate on rock grounds. The ecologic information that can be derived from the shells depends on the diVerent post-mortem histories of the faunas. © 2000 Elsevier Science B.V. All rights reserved.

The coral-inhabiting snails, Coralliophila violacea (Lamarck), are widely distributed in the Indo–Pacific region. It has been inferred from field data that sex changes have occurred and might be influenced by neighbors. In this study, we designed a field experiment with 2 treatments, i.e. `single males' and `male–female pairings' to test the hypothesis of sex changes as well as the role of neighbors on sex changes. Snails were collected by SCUBA diving from the surface of massive coral Porites lobata in shallow waters (

Corallivores are known to have a substantial impact on community structure and dynamics of Indo-Pacific reefs but thus far western Atlantic corallivores have been assumed to be largely unimportant. Recent evidence, however, suggests that at least one Caribbean coral predator, the gastropod Coralliophila abbreviata (Lamarck), may be of considerable importance. In the fall of 1987, I studied patterns of distribution, movement and feeding in C. abbreviata on a patch reef off the Caribbean coast of Panama. Snails were abundant on the reef but were virtually confined to only three of 27 zooxanthellate scleractinian species found there, i.e., Acropora cervicomis (Lamarck), Agaricia tenuifolia Dana and Montastrea annulons (Ellis & Solander). At any one time, snails were most abundant on the latter species, especially on lobate colonies. Groups of snails rapidly moved on and off A. cervicornis but were quite sedentary on the other two prey species. Snails were more active at night and those found on A. cervicornis were larger than those on A. tenuifolia. More than one-third of monitored colonies of A. cervicornis exposed to snail predation in the field died in