Supplementary Information from Host size and proximity to diseased neighbours drive the spread of a coral disease outbreak in Hawai‘i

1) Equations for pathogen load proxies; 2) Table S1 Comparison of top four models explaining infection likelihood; 3) Table S2 Range for optimal disease transmission; 4) Figure S1 Distribution plots of host, pathogen, and environmental factors; 5) Figure S2 Spatial variation in host and environment factors; 6) Figure S3 Spatial variation in pathogen and environment factors

Data from Host size and proximity to diseased neighbours drive the spread of a coral disease outbreak in Hawai‘i

Data from coral disease outbreak surveys

Analysis code from Host size and proximity to diseased neighbours drive the spread of a coral disease outbreak in Hawai‘i

Code to conduct analysis in R statistical software

Quantitative analysis of amoebocytes in mesoglea of sea fans experimentally exposed to <i>Aspergillus sydowii</i>.

<p>A) Increase in amoebocytes in sea fans exposed to fungal hyphae, n = 14, <i>X</i>² = 41.85, p<0.0001. B) Fine spatial analysis of amoebocyte surface area at point of fungus exposure and 1, 4, and 8 mm away. Dashed line indicated control or basal % amoebocyte surface area. Data presented are mean±s.e.m, n = 8, F = 18.95, p = 0.015. Asterisk denotes significant differences at p<0.05.</p

Prophenoloxidase activity in healthy and diseased sea fans as measured by the oxidation of L-dopa to dopachrome.

<p>Data presented are mean±s.e.m n = 12, F = 4.7, p = 0.040.</p

Histological images of sea fans infected with <i>Aspergillus sydowii</i> and presence of melanin both as a band and in amoebocytes as melanosomes.

<p>A) Histological preparation of an infected coral stained with H&E showing individual fungal hyphae (F) in skeleton and surrounded by melanin (M). Note granular amoebocytes (ga) aggregated near melanin and fungal hyphae. Scale bar = 25 µm. B) Histological preparation of an infected coral showing multiple amoebocytes containing melanin granules in contact with the thick layer of melanin preventing <i>A. sydowii</i> hyphae within the axial skeleton (at left) from contacting the sea fan tissue (on right). Fontana-Masson staining procedure, scale bar = 25 µm. C) Close up of an amoebocyte containing melanin granules (Mg) and black stained melanin (M) layer surrounding fungus (F). Fontana-Masson staining procedure, scale bar = 10 µm D) Uninfected coral stained with Fontana-Masson's procedure showing lack of melanin and melanin granules. Scale bar = 10 µm.</p

Picture of a sea fan coral (<i>Gorgonia ventalina</i>) infected with <i>Aspergillus sydowii</i>, multifocal purple annular lesions are indicative of infection (photo by Ernesto Weil).

<p>Picture of a sea fan coral (<i>Gorgonia ventalina</i>) infected with <i>Aspergillus sydowii</i>, multifocal purple annular lesions are indicative of infection (photo by Ernesto Weil).</p

Amoebocytes in mesoglea (connective tissue) of naturally diseased sea fan corals.

<p>A) Healthy coral with granular amoebocytes dispersed in mesoglea as indicated by arrows. B) Diseased coral with an increase in granular amoebocytes in the mesoglea. Scale bar = 25 µm.</p

Increase in amoebocyte surface area in sea fans exposed to elevated temperature (31.5°C) for 8 days.

<p>Data presented are mean±s.e.m, n = 6, <i>X</i>² = 305.11, p<0.0001.</p

Amoebocytes are heterogeneously distributed within individual naturally infected sea fan colonies.

<p>Data presented are mean±s.e.m, n = 8, <i>X</i>² = 12.43, p = 0.0004.</p