Temperature Dependence of Respiration in Larvae and Adult Colonies of the Corals Acropora tenuis and Pocillopora damicornis

Abstract

Although algal symbionts can become a source of reactive oxygen species under stressful conditions, symbiotic planulae of the coral Pocillopora damicornis are highly tolerant to thermal stress compared with non-symbiotic planulae of Acropora tenuis. As a first step to understand how P. damicornis planulae attain high stress tolerance, we compared the respiration rate and temperature dependence between symbiotic planulae of P. damicornis and non-symbiotic planulae of A. tenuis, as well as between larvae and adult branches within each species. Larvae and adult branches of both species had similar temperature dependency of respiration rate, with the temperature coefficient (Q10) values of about 2. Planula larvae of P. damicornis had a significantly lower respiration rate than that of A. tenuis larvae at 25-30 °C, but not at 32 °C, whereas adult branches of P. damicornis had a significantly higher respiration rate than that of A. tenuis branches at all temperatures. Thus, P. damicornis larvae appear to be capable of reducing their respiration rate to a greater extent than A. tenuis larvae, which could partly explain why P. damicornis larvae had high survivorship under thermal stress, although other antioxidant or photoprotective mechanisms should be investigated in the future.

Warming resistant corals from the Gulf of Aqaba live close to their cold-water bleaching threshold

“…A similar result was noted for Montipora digitata where F v / F m decreased more than 50% from initial values after two weeks at 17.6 °C and yet did not display any corresponding decrease in protein concentration ( Kavousi, Parkinson & Nakamura, 2016 ). Maintenance of total protein concentration and absence of mortality despite reduced energy production may be possible since metabolism, and therefore energy demand, decreases at lower temperatures ( Schulte, Healy & Fangue, 2011 ; Schulte, 2015 ) as has been demonstrated in corals (e.g., ( Coles & Jokiel, 1977 ; Haryanti & Hidaka, 2015 )). Declining metabolism is not evident in this study.…”

Genomic and transcriptomic signals of thermal tolerance in heat‐tolerant corals (Platygyra daedalea) of the Arabian/Persian Gulf

“…Other unknown correlations among traits may act in the same way, limiting adaptive responses to selection and maintaining genetic variation in this trait. Finally, this study examined thermal tolerance in aposymbiotic larvae, which can differ in response compared to conspecific adults in corals and many other marine invertebrates (e.g., Collin & Chan, ; Haryanti & Hidaka, ; Peck, Souster, & Clark, ; Putnam, Edmunds, & Fan, ; Webster et al, ). Adult colonies in this population also harbour symbiotic dinoflagellates that are closely related to Symbiodinium thermophilum (Howells et al, ), which provides both thermal and salinity tolerance in other corals in the Gulf (D’Angelo et al, ; Hume et al, ).…”

Peer Review #3 of "Warming resistant corals from the Gulf of Aqaba live close to their cold-water bleaching threshold (v0.1)"

“…Maintenance of total protein concentration and absence of mortality despite reduced energy production may be possible since metabolism, and therefore energy demand, decreases at lower temperatures (Schulte, Healy & Fangue, 2011;Schulte, 2015) as has been demonstrated in corals (e.g. Coles & Jokiel, 1977;Haryanti & Hidaka, 2015). Declining metabolism is not evident in this study.…”