title: Gross and microscopic pathology of hard and soft corals in New Caledonia.
abstract: We surveyed the reefs of Grande Terre, New Caledonia, for coral diseases in 2010 and 2013. Lesions encountered in hard and soft corals were systematically described at the gross and microscopic level. We sampled paired and normal tissues from 101 and 65 colonies in 2010 and 2013, respectively, comprising 51 species of corals from 27 genera. Tissue loss was the most common gross lesion sampled (40%) followed by discoloration (28%), growth anomalies (13%), bleaching (10%), and flatworm infestation (1%). When grouped by gross lesions, the diversity of microscopic lesions as measured by Shannon-Wiener index was highest for tissue loss, followed by discoloration, bleaching, and growth anomaly. Our findings document an extension of the range of certain diseases such as Porites trematodiasis and endolithic hypermycosis (dark spots) to the Western Pacific as well as the presence of a putative cnidarian endosymbiont. We also expand the range of species infected by cell-associated microbial aggregates, and confirm the trend that these aggregates predominate in dominant genera of corals in the Indo-Pacific. This study highlights the importance of including histopathology as an integral component of baseline coral disease surveys, because a given gross lesion might be associated with multiple potential causative agents.
authors.affiliation: U.S. Geological Survey, National Wildlife Health Center, Honolulu Field Station, PO Box 50187, Honolulu, HI 96850, USA. Electronic address: Thierry_work@usgs.gov.
authors.forename: Thierry M
authors.initials: TM
authors.lastname: Work
authors.affiliation: Hawaii Institute of Marine Biology, PO Box 1346, Kaneohe, HI 96744, USA.
authors.forename: Greta S
authors.initials: GS
authors.lastname: Aeby
authors.affiliation: BIOCENOSE MARINE Sarl, Centre IRD de Nouméa, 98848 Nouméa Cedex, New Caledonia.
authors.forename: Gregory
authors.initials: G
authors.lastname: Lasne
authors.affiliation: UMR IPSL-LOCEAN (UPMC/CNRS/IRD/MNHN), Centre IRD France Nord, 32 Av. Henri Varagnat, 93143 Bondy Cedex, France.
authors.forename: Aline
authors.initials: A
authors.lastname: Tribollet
mesh_terms: D000818:Animals; D037421:Anthozoa / Q000382:microbiology*; D009510:New Caledonia
keywords: Coral; Disease; Endolithic hypermycosis; Histopathology; New Caledonia; Porites trematodiasis