Abstract Coral bleaching is a complex physiological response to environmental stressors, primarily temperature fluctuations, that induces oxidative damage, disrupting the intracellular symbiotic relationship between corals and their dinoflagellate algae and/or reducing the algae’s photosynthetic pigments. Coral recovery from bleaching often depends on the re-establishment of this symbiosis, with associated fauna potentially influencing coral resilience by either mitigating or exacerbating bleaching effects. Yet this subject remains underexplored, particularly regarding invertebrates. Here, we investigated the physiological response of the ten-ray star coral Madracis decactis to thermal stress and the impact of the coral-associated crab Mithraculus forceps on its recovery from bleaching. In a laboratory experiment, we subjected coral fragments to a 21-day thermal stress, followed by a 4-week recovery period, and assessed key parameters of the coral–algae symbiosis and the oxidative-stress response. Our results showed that heat stress caused severe impacts on coral physiology, with persistent bleaching effects on the coral–algae symbiosis and no signs of recovery. Additionally, we found that the presence of Mi. forceps had a negligible effect on Ma. decactis fragments, with no influence on the coral’s overall condition or recovery from thermal bleaching under the conditions tested. However, more complex ecological scenarios may reveal context-dependent crab roles that could influence coral recovery, highlighting the need for studies that incorporate broader biotic and abiotic interactions.
Roriz et al. (Thu,) studied this question.