Temperature and symbiosis affect lesion recovery in experimentally wounded, facultatively symbiotic temperate corals

[摘要] The health of most reef-building corals depends upon an intracellular symbiosis with photosynthetic dinoflagellates of the genus Symbiodinium that is acutely sensitive to increasing ocean temperatures. However, distinguishing the individual effects of both temperature and symbiotic state on coral health is difficult to investigate experimentally in most tropical corals because the symbiosis is obligate. Here, we varied temperature (9, 18, 24°C) and symbiotic state (symbiotic, aposymbiotic) in the facultatively symbiotic, temperate scleractinian coral Astrangia poculata to explore the individual impact of temperature and symbiosis on wound healing, an important component of coral resilience, by determining wound size using calibrated photographs and characterizing developmental stage through the healing process over time. Symbiotic corals demonstrated a significant healing advantage over corals with lower densities of S. psygmophilum (aposymbiotic state), regardless of temperature. In addition, overall recovery success of both symbiotic states increased with temperature. These data suggest that a functional symbiotic relationship with S. psygmophilum promotes lesion recovery despite heterotrophic energy sources. Reductions in healing rate and tissue cover near the wound site under cold temperatures suggest that wound healing is compromised during the winter in these temperate corals. This study demonstrates that supplemental energy sources from symbiosis, coupled with optimal growth conditions, promote wound healing and may offer insight into factors enhancing wound recovery in tropical corals.

[学科分类] 海洋学与技术

[关键词] Coral;Recovery;Symbiosis;Temperature;Lesions