Biology subjects

Galindo-Martinez, C. T.

Publications and source records attributed to Galindo-Martinez, C. T..

3 recordsLinked to original sources

bioRxiv2026

Elevated environmental CO2 stimulates photosynthesis and induces differential oxidative responses in two Caribbean reef-building coral species

Reef-building corals maintain intracellular photosymbiosis with dinoflagellate algae, allowing them to use photosynthetic products as metabolic fuel. Carbon dioxide (CO2) is a key substrate for photosynthesis, but its rapid increase in the global ocean due to anthropogenic emissions (known as ocean acidification) may disrupt coral symbiosis. We examined the effects of elevated CO2 on photosynthetic O2 production, oxidative damage, and antioxidant systems in the Caribbean reef-building corals Porites astreoides and Orbicella franksi. Coral colonies collected at 3m depth in Bocas del Toro (Panama) were exposed to control (390 {micro}atm CO2, pH ~8.00) or elevated CO2 ({approx}1,060 {micro}atm CO2, pH {approx}7.70) conditions in outdoor flow-through aquaria for 10 days. Flowing seawater had higher O2O2 concentrations in elevated CO2 tanks, with the largest differences at higher irradiance. Microsensor measurements confirmed that acute and chronic exposure to elevated CO2 significantly stimulated photosynthetic O2 production in both species. Despite increased O2 production. neither species showed significant changes in lipid peroxidation, reduced glutathione, or superoxide dismutase, catalase, and glutathione-S-transferase activities. Protein oxidation was unchanged in O. franksi but significantly decreased in P. astreoides. These results are consistent with partial relief of carbon limitation in P. astreoides symbionts under elevated CO2, potentially improving photosynthetic efficiency and decreasing reactive oxygen species production. These findings support the resilience of P. astreoides to OA and suggest that elevated CO2 may increase daytime O2 levels on future reefs, with implications for the aerobic metabolism of reef organisms.

physiology↗

bioRxiv2024

Bacteria-powered living materials enable coral larval settlement

The global decline of coral reefs calls for new strategies to rapidly restock coral populations and maintain ecosystem functions and services. Low recruitment success on degraded reefs hampers coral sexual propagation and contributes to limited genetic diversity and reef resilience. Here, we introduce a living bacteria-powered reef ink (Brink) for assisted coral recruitment. Brink can be rapidly applied to restoration substrates via photopolymerization, and it has been formulated to cultivate two settlement-inducing bacterial strains (Cellulophaga lytica and Thalassotalea euphylliae). Settlement assays performed with broadcast spawning (Montipora capitata) and brooding (Pocillopora acuta) Indo-Pacific corals showed that Brink-coated substrates increased settlement >5-fold compared to uncoated control substrates. Brink can be applied as a coating or 3D bioprinted, leading to various potential applications for integration with reef engineering. Our approach underscores the potential of using functional living materials for augmented ecosystem engineering and reef rehabilitation. SynopsisThis study introduces a functional and sustainable bacteria-powered living material that enhances coral settlement, promoting coral reef rehabilitation and ecosystem resilience.

bioengineering↗

bioRxiv2021

Physiological and ecological consequences of the water optical properties degradation on reef corals

Degradation of water optical properties due to anthropogenic disturbances is a common phenomenon in coastal waters globally. Although this condition is associated with multiple drivers that affect corals health in multiple ways, its effect on light availability and photosynthetic energy acquisition has been largely neglected. Here, we describe how declining the water optical quality in a coastal reef exposed to a turbid plume of water originating from a man-made channel compromise the functionality of the keystone coral species Orbicella faveolata. We found highly variable water optical conditions with significant effects on the light quantity and quality available for corals. Reduction of light penetration into the water column elicits the development of low-light phenotypes close to theoretical limits of photoacclimation despite their occurrence at shallow depths. Predicted photosynthetic energy depletion with increasing depth is associated with patterns of colony mortality and contraction of the habitable space for the population. A numerical model illustrates the potential effect the progressive degradation of water optical properties on the gradual mortality and population decline of O. faveolata. Our findings suggest that preserving the water optical properties seeking to maximize light penetration into the water column may have an extraordinary impact on coral reefs conservation, mostly toward the deeper portions of reefs.

physiology↗