Differences in the progression rate of SCTLD in Pseudodiploria strigosa are related to colony size and morphology

Abstract

Stony Coral Tissue Loss Disease (SCTLD) impacts are unprecedented concerning the level of devastation they have imposed on Caribbean coral assemblages. Although SCTLD affects nearly 30 different coral species, it has been particularly lethal for Pseudodiploria strigosa. Mortality rates for this species are estimated to be between 60 and 100% in the Caribbean; however, tissue-loss rates have been shown to differ among colonies, which suggests that colony health, environmental conditions, and concurrent transmission events are crucial to the development of the disease at reef scale. To gain insight into the colony-level dynamics of SCTLD, we used a simplified photogrammetry and 3D modeling approach to quantify and compare SCTLD-related tissue-loss rates among 20 colonies of P. strigosa on a shallow back-reef in the Mexican Caribbean. Over a six-month period, SCTLD resulted in the full mortality of 70% of the colonies that were tagged shortly after infection. Although disease progression followed a multifocal-type infection in most cases, tissue-loss rates significantly differed among colonies. Some colonies died within the first 20 days of observation, while others died towards the end of the study period. We found a significant positive effect of colony size on rates of tissue loss disease, as well as evidence suggesting that elongated and vertically compressed colonies have a greater probability of experiencing higher tissue-loss rates than colonies with more spherical shapes. The observed relationship between colony morphology and tissue-loss rates is likely a result of elongated colonies having more flat surface area at the top of the colonies which facilitates accumulation of sediments, which have been shown to be a source of SCTLD transmission.

In silico characterization of Cnidarian’s antimicrobial peptides

“…The above, outlines them as candidates for therapeutic applications. These peptides with putative antibiotic properties could be evaluated to be used to treat corals that face threats of an infectious nature, such as the white band disease that affects acroporid corals (Aronson and Precht, 2001) or the devastating Stony Coral Tissue Loss Disease (SCTLD) that currently affecting the integrity of the Mesoamerican reef (Camacho-Vite et al, 2022). This type of method was tested on the species Montastraea cavernosa, where different antibiotics were used to treat diseased corals (Shilling et al, 2021).…”

Capricious commensalisms: Consumption of coral spawn by the ruby brittle star (Ophioderma rubicundum)

“…The two coral species whose gametes were consumed are particularly vulnerable; O. faveolata was listed as "threatened" under the US Endangered Species Act in 2014, and P. strigosa was recently reclassified as "critically endangered" by IUCN (Rodríguez-Martínez et al 2022), having experienced considerable declines in recent years due to stony coral tissue loss disease (Camacho-Vite et al 2022). As coral populations decline and their spawning becomes less synchronized (Gardner et al 2003;Levitan & McGovern 2005;Shlesinger & Loya 2019), any additional pressures on their fecundity may decrease fertilization success, reduce recruitment, and inhibit community recovery following disturbance .…”

Opportunistic consumption of coral spawn by the ruby brittle star (Ophioderma rubicundum)

“…The two coral species whose gametes were consumed are particularly vulnerable; O. faveolata was listed as “threatened” under the US Endangered Species Act in 2014, and P. strigosa was recently reclassified as “critically endangered” by IUCN (Rodríguez‐Martínez et al, 2022), having experienced considerable declines in recent years due to stony coral tissue loss disease (Camacho‐Vite et al, 2022). Coral reproduction is already compromised; as the number of potential parent corals declines and spawning becomes less synchronized (Gardner et al, 2003; Levitan & McGovern, 2005; Shlesinger & Loya, 2019), external pressures such as gamete predation may further decrease fertilization success, reduce recruitment, and inhibit community recovery following disturbance (Hughes et al, 2000; Hughes & Tanner, 2000; Oliver & Babcock, 1992).…”