Quick Look Report: Dendrogyra cylindrus spawning – August 2019

In August 2019, Nova Southeastern University led a multi-agency effort to observe and collect gametes from spawning pillar coral (Dendrogyra cylindrus) colonies in the Western Dry Rocks region of the Lower Florida Keys. For two nights, four boats and 29 personnel representing five agencies/institutions recorded data and collected eggs and sperm for propagation of the species. Field spawning closely matched predicted dates and times from previous years. Larvae were transported to Florida Aquarium’s Center for Conservation for settlement. Development could not be observed several hours after spawning, but the following morning, numerous larvae were observed. Many of these were greatly diminished in size from the normal larvae and may be a result of damaged eggs or embryos disturbed during early development. The impact of Stony Coral Tissue Loss Disease on the parent colonies may also have reduced developmental success, and the impact of this disease on D. cylindrus populations has reduced wild colony numbers to a point where future wild spawning collections are most likely unobtainable. However, in addition to the juveniles produced in the past and the larvae produced from 2019 collections, the long-term knowledge gained from wild spawning observations and collections has built the knowledge that now allows facilities to spawn, collect, settle, and rear juveniles of this species into the future.