From Red To Med – Report Identifies Top Candidates For Lessepsian Migration
Since the opening of the Suez Canal over 150 years ago, more than 120 fish species have migrated from the Red Sea to the Mediterranean. Researchers at Tel Aviv University have now created a statistical model that predicts which species might embark on this journey next.
The model has identified several leading candidates, including the stellate pufferfish (Arothron stellatus), cinnabar goatfish (Parupeneus heptacantha), and yellowspotted trevally (Turrum fulvoguttatum). The complete list can be found in the published study.
Dr. Shahar Chaikin led the research as part of his doctoral studies at Tel Aviv University, under the guidance of Prof. Jonathan Belmaker from the School of Zoology, the Wise Faculty of Life Sciences, and the Steinhardt Museum of Natural History. Other contributors to the study included Dr. Tal Gavriel, doctoral student Avery Deveto, and Shahar Malamud. The results were published in the Journal of Animal Ecology.
This new model evaluates Red Sea fish species based on their potential to successfully establish themselves in the Mediterranean. Instead of merely recounting past invasions, the researchers aimed to create a tool that would assist scientists and environmental authorities in predicting future invasions. As sea temperatures rise, making the Mediterranean more welcoming to tropical species, this model could serve as a vital resource for environmental monitoring, early detection of invasive species, and effective conservation planning.
What factors contribute to a fish’s success as an invader? To explore this question, researchers utilised stereoscopic baited remote underwater video systems (stereo-BRUVs) at depths between 5 and 150 metres (16 to 492 feet) in both the Gulf of Eilat and along the Mediterranean coast of Israel.
By analysing hundreds of hours of underwater footage, they studied 179 fish populations, comparing species that have already invaded the Mediterranean with closely related species that remain in the Red Sea.
In contrast to earlier studies that only looked at species that had completed their migration, this research also investigated their source populations in the Red Sea. This approach enabled the team to pinpoint the traits that were present prior to the invasion.
Surprisingly, the strongest predictor of invasion success was not what they expected. Instead of being ecological “generalists” that can thrive in various environments, the fish most likely to invade the Mediterranean were those that were least reliant on coral reefs.
Chaikin explains, “The Suez Canal and the Mediterranean contain very few coral reefs like those found in the Red Sea. Species that depend on coral reefs are therefore unlikely to complete the journey. The fish that succeed in invading are those that do not rely on coral reefs for survival in the first place.”
The research additionally showed that fish alter their behaviour upon reaching the Mediterranean. Rather than sticking to the same habitats they frequented in the Red Sea, successful invaders swiftly adjust to the conditions present in their new surroundings.
The scientists also discovered that invasive fish do not mainly inhabit vacant ecological niches, as was often thought. Instead, they take up residence in the same habitats as native Mediterranean species, indicating that the competition for food, shelter, and space could be significantly more fierce than previously understood.
Belmaker says, “Until now, researchers have tried to understand biological invasions primarily by examining species that had already reached the Mediterranean. We took a step back and asked what characterises these species before they begin their journey. This distinction allows us to move beyond explaining invasions that have already occurred toward predicting the next ones.”
With the Mediterranean Sea warming, researchers anticipate that tropical fish will find it easier to settle in the region. They think that predictive models like this could play a crucial role in environmental monitoring initiatives, enabling scientists to detect new species earlier and to better prepare for the upcoming ecological shifts.
Shahar Chaikin et al, Native habitat affinities predict fish invasions with post‐invasion habitat shifts, Journal of Animal Ecology (2026). DOI: 10.1111/1365-2656.70293
Journal information: Journal of Animal Ecology
