Coral Health and Disease in the Pacific: Vision for Action

sized central area of dead coral overgrown by algae. Polyps near the edge of theselesions appeared atrophied or entirely missing. Yellow bleachings (Fig. 5C-D)designated dwell-defined areas of bleached coral with a yellow hue and no distinct raisedmargin. These areas were separated from live coral and often had incipient algal growthon coral tissue. Brown blotch corresponded to single well-defined circular dark brownlesions on coral tables, usually near the middle of the plate, and was characterized by afilm of brown mucoid material surrounded by apparently normal coral tissue. Growthanomalies (Figs. 5E, 6, 7A-B) included any abnormal growths of the coral skeleton.Brown bands (Fig. 5F) were slice-shaped areas of dead coral overgrown with algaedemarcated from adjacent normal coral by a distinct band of bleached tissueGrowth anomalies in A. cytherea were of 3 types: Grossly, type 1 (Figs. 5E, 6A-B) growths were focal to coalescing, white to pink, and rugose, and tissue covering thesemasses was smooth and bereft of polyps. On histology (Fig. 6C), coenosarc epitheliumwas markedly hyperplastic and characterized by numerous pseudostratified columnarcells. Polyps were absent or manifested by rare batteries of spirocysts. The mesogleawas enlarged, and gastrodermal cells adjacent to epithelium were markedly hyperplasticto anaplastic, pleomorphic, and characterized by stellate nuclei, and widened intercellularspaces. Gastrodermis of gastrovascular canals was focally hyperplastic with clumps ofproliferating cells free or projecting within the lumen of canals. Based on thesecharacteristics, this lesion was considered neoplastic and classified as a gastrodermalneoplasm. Zooxanthellae were rarely seen. In some instances, calicoblast cells appearedenlarged and hypereosinophilic with swollen nuclei. Rare mesenteric filamentscontaining macrobasic mastigophores were noted.Type 2 growths (Fig. 6D-E) were focal to coalescing, pink, with numerouscylindrical tubercles with an apical indentation. Tissue overlying these growths wasgenerally bereft of polyps save for occasional single tentacles. On histology, (Fig. 6F)there was marked hyperplasia of coenosarc epithelium with cleft formation andthickening of mesoglea. Coenosarc gastrodermis was composed of simple columnar cellsand that of gastrovascular canals was cuboidal and focally hyperplastic. Zooxanthellaand mesenteric filaments were rarely seen. Calicoblast layer was uniformly squamous.Type 3 growths (Fig. 7A) consisted of smooth, well-defined, sessile white firmgrowth arising from normal skeleton. Tissue overlying these growths lackedzooxanthella. On histology, tumor tissue was characterized by a markedly hyperplasticepithelium bereft of polyps. Coenosarc gastrodermis was largely bereft of zooxanthellaand focally hyperplastic with stellate nuclei. Within gastrovascular canal, gastrodermalcells, particularly those associated with mesenteric filaments, were hyperplastic,fibroblast-like and pleomorphic forming papillary projections into the gastrodermalcavity. Myonemes within occasional mesenteric filaments were enlarged andoccasionally diffusely necrotic. Diffusely, calicoblast was squamous and focallyhyperplastic. Based on pleomorphic appearance of gastrodermal cells and cellularnecrosis, these growths were classified as gastrodermal neoplasms.Pocillopora eydouxiGrossly, lesions were characterized by exuberant growth of skeleton overlaid byapparently normal tissue (Figs. 7D-E). These were seen in one location on the northlagoon and Site 3. On histology, no significant lesions were noted save for markedly219