Lidor Shtruzer,
Marine Biologist

Born in Eilat in 1996, Lidor is a technical diver and marine scientist who began technical diving in 2017 and by 2019 earned Trimix (TDI, closed-circuit) and Divemaster (SDI) certifications. He joined Israel’s Underwater Missions Unit in 2019 and, after specialized training, served as a diving officer. Now an MSc candidate in marine molecular biology at Bar-Ilan University and a student in Prof. Oren Levy’s lab, he studies how corals sense and respond to light across depth gradients and lunar cycles - linking photoreceptor pathways to gene-expression dynamics in Stylophora pistillata through in-situ and aquarium experiments. His work integrates field sampling, next-generation sequencing, and robust bioinformatics to reveal mechanisms of resilience that inform reef conservation. In 2024 he joined the board of the Israeli Diving Federation, advancing diver education and reef conservation.

15 October 2025

Daylight and Ecosystems: What Coral Reefs Can Teach Us About the Language of Light

Light is more than illumination, it’s information. Across ecosystems, organisms use subtle changes in sunlight and moonlight to synchronize their behavior and physiology. Coral reefs, shaped by these daily and lunar rhythms, are among the most striking examples of life organized by light. Corals live in partnership with photosynthetic algae that transform sunlight into energy, sustaining both partners and much of the reef ecosystem. But corals are not passive hosts. Even without eyes or a nervous system, they detect variations in wavelength, intensity, and timing, adjusting feeding, metabolism, and reproduction in response. Their mass spawning events, for instance, occur in precise alignment with the phases of the moon.

Figure 1. Coral reef ecosystem in the Gulf of Aqaba/Eilat, Red Sea, Israel, where sunlight can penetrate the clear blue water to depths of up to 100 meters. The grant focuses on understanding how corals sense and respond to light across shallow to deep-water habitats. Photo credit: Meron Segev.

At the Marine Molecular Ecology Lab, led by Prof. Oren Levy, we investigate how corals perceive and interpret their luminous environment. Using molecular and single-cell approaches, we map the expression of light-sensitive genes such as opsins and cryptochromes across different coral cell types. Our model species, Stylophora pistillata, inhabits reefs spanning a wide light gradient, from shallow, high-irradiance habitats to mesophotic zones where only faint blue light remains. These data allow us to explore how corals tune their internal processes to the surrounding light field.

We are beginning to see how different cells and molecular pathways respond to daily and lunar cycles, revealing a complex light-sensing architecture that evolved long before the appearance of eyes. This project is conducted in collaboration with Prof. Kristin Tessmar-Raible at the University of Vienna, whose work on biological clocks and photoreceptors in marine species provides key comparative insight. Together, we aim to understand how early-diverging animals decode the spectral and temporal cues that structure ocean life.

Figure 2. Lidor Shtruzer, affiliated with this grant, diving to collect coral samples for the molecular characterization of photoreceptors in the Gulf of Aqaba/Eilat, Red Sea, Israel. Photo credit: Meron Segev.

Beyond corals, these findings touch on a universal theme: the molecular language of light is shared across life. The same families of photoreceptors guiding coral behavior also regulate circadian rhythms in plants, insects, and humans. Understanding how corals perceive their light environment not only deepens our view of evolution but also informs conservation strategies as artificial light increasingly alters natural cycles in the sea.

Figure 3. A nocturnal view of a coral reef in the Gulf of Eilat under ultraviolet light reveals the diversity of light responses in reef organisms. At the center, a sponge fluoresces yellow-green from UV-reactive pigments. On the right, the brain coral Platygyra lamellina glows green from Green Fluorescent Protein; GFP-like, while the branching Acropora on the left remains dark, illustrating species-specific differences in photoprotection and light use. Photograph by Lidor Shtruzer, Oren Levy’s Marine Molecular Biology Lab, Bar-Ilan University.

Some impressions from The Marine Molecular Ecology Lab (LMME)

Daylight and Ecosystems: What Coral Reefs Can Teach Us About the Language of Light

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