Resistance to desiccation and healing regeneration in the sun coral

Abstract

Sun corals, Tubastraea spp., are native to the Indo-Pacific Ocean, but have established populations in different areas of the Atlantic Ocean. Tubastraea spp. are considered invasive in Brazil, being targets of a National Plan for Prevention, Control and Monitoring. One of the objectives of this plan is to develop scientific research and technology, focused on subsidies for the prevention and management of sun coral dissemination. Through manipulative experiments under controlled laboratory conditions, we analyzed the effects of exposure to air in sun coral colonies during different time intervals, to provide general biosecurity subsidies for possible management operations using desiccation. In addition, we recorded the coral ability to regenerate soft tissues damaged after trauma due to desiccation. We observed that Tubastraea sp. resists up to four hours out of seawater without permanent damage, despite being a typical subtidal organism. The number and severity of wounds and loss of soft tissues increased with exposure time to air, which affected the recovery capacity of this coral. Full mortality of the colonies (all polyps dead) was achieved only after four days of exposure to air. In addition, the healing regeneration process was recorded here for the first time in sun corals. The proportion of polyps partially retaining soft tissues involved in feeding is determining for the recovery of the entire colony, which can occur in just two weeks. Such data offer relevant biosecurity subsidies for possible management operations using desiccation.