Behavioural
Ecology Group


Between two oceans: Lionfish cognition and environmental change





Lionfish (Pterois spp.) are charismatic reef fish, often the highlight of a recreational dive, but there is a face to them that is not commonly known. Native to the Indo-Pacific ocean, lionfish have recently become one of the most successful marine invaders of the Atlantic and Mediterranean. They are generalist predators that consume a wide variety of invertebrates and fishes. With a grand appetite, a stomach that expands 30 times its normal size, and no known predators, Lionfish have caused great damage in the Atlantic by drastically reducing reef fish, with detrimental consequences for the reefs. For instance when algal eaters disappear algae can overgrow corals and destroy reef stability. Also, in the native habitat it seems that lionfish are doing particularly well at deteriorated reefs, but it is not known if this is causally linked. To understand these dynamics researchers have investigated many traits of lionfish, such as reproductive rate, feeding behaviour or dispersal abilities, but we think that their cleverness might be the key. This project therefore aims to provide a better understanding of the role of cognition when animals adapt to new environments. We do this by studying lionfish in the wild in the Mediterranean, Caribbean and Red Sea, and in the laboratory at Wageningen University. You can join our team as a thesis student!



Survey



ongoing projects



Where are the fish ? Citizen Science

Encountering Lionfish (Pterois spp.) upon snorkeling or diving is an exciting sighting to many of us, but behind their flared fins and elaborate coloration lies an efficient predator and one of the most dangerous invasive species in the Atlantic and Mediterranean Sea. This new-comer from the Indo-Pacific has brought many negative impacts to many reef ecosystems in the Atlantic ocean. Our projects consists of many aspects, like testing lionfish for their behavior and cognition in both native and invasive habitats, to reveal how this fish has become such a successful predator and marine invader, but first we need to know where the lionfish are and where they have spread! To achieve this, we launched a citizen science survey that invites all divers, snorkelers, and beach goers anywhere in the world to help us find out where lionfish are and where they have been by submitting their sightings of Lionfish whether recent or old. In this way we can better track their abundance in the Red Sea, invasion in the Mediterranean, and gain a better understanding of the relationship between their cognition and environment. Please visit the link below to submit your Lionfish sightings!


Survey

Red Sea – reef quality vs. cognition

Recently local disturbances have increased dramatically along the Egyptian Red Sea reefs and observational evidence suggests that deteriorated reefs harbour increased Lionfish (Pterois miles) densities. Such alteration of reefs likely impacts fish behavior. In this project, we investigate the relationship between reef health status and lionfish densities in its native Red Sea habitat. We further examine Lionfish cognitive abilities as one likely factor that could help Lionfish cope and even flourish with environmental change. We ask the following questions: What is the relationship between reef health status and Lionfish densities? Can we expect Lionfish to act invasively in its native range by bringing negative impact to local Red Sea reefs as they do in the invaded Atlantic? On a broader scale, this project aims to expand on our current understanding of the ecological and evolutionary implications caused by anthropogenic stressors in marine ecosystems by studying lionfish ecology and behaviour. For further information about this project and to get in touch, please visit Nada’s Personal Page or follow us on twitter @NadaShanawany.


Cognition of invasion

Indo-Pacific lionfish are efficient predators and lately one of the most dangerous invasive species in the Atlantic and Mediterranean. Often their invasion success had been attributed to their morphological and physical characteristics, such as their generalist diet, high reproductive rate, and unique hunting style. What is overlooked though, is how behaviour and cognition may play a role in their ability to invade, so we are investigating this in lionfish. How are cognitive abilities and invasion processes linked? How do animals cognitively adapt to novel environments? What makes some species like the lionfish good invaders and which cognitive traits are important for such processes? To see more detailed information on this project, see Elizabeth’s Personal Page or follow us on twitter @lizwphillips17.


Lionfish cognition

Lionfish have 18 spines that carry a painful venom. Consequently, they seem to have no real predators. How is such a lifestyle linked to their cognitive abilities? Some think that relaxed predation pressure allows for decreased investment in cognitive abilities. So, lionfish may save energy on their brains and focus on building their protective weaponry. Does this mean they are not the sharpest knife in the drawer? We are testing this and several other ideas in the lab. We are slowly beginning to understand just how smart those animals are, and it will be exciting to see how far we can push the boundaries of cognition in these unique animals. Follow us on twitter: @KotrschalA





blog



By Anna Schoonhoven


Last summer I got the opportunity to do fieldwork in Cyprus! Here, I tell you all about this adventure, the challenges, and the amazing times. It all started while searching for a topic for my bachelor thesis. I got in touch with Alexander Kotrschal, right around the same time he was recruiting a dive team to investigate the cognition and behaviour of the invasive lionfish in the Mediterranean Sea. When I heard this, I definitely wanted to join. Shortly after, we did our first SCUBA dive in the Netherlands to get to know the team and to refresh the techniques. We finished further preparations and were ready to go. Suddenly, a week before take-off, we learned that the WIAS directors had recently banned all SCUBA diving due to some legal issues. This has since been resolved but made diving impossible then - the first major challenge. No SCUBA diving meant not being able to do our projects as planned, such as work with underwater cages, tag the fish on location, or work at certain depths. After an emergency meeting in which we had a long discussion about whether a meaningful project was still doable, we decided to go - we wanted to study the behaviour of the invading lionfish in its new range, and we all felt fit for freediving. Once in Cyprus, the weather was amazing, the sky and sea so blue. By the time I arrived, a part of the field crew already set up and explored the area. I got the feeling to be really part of this team. Together we were figuring out what to do, what works and what does not. Instead of SCUBA diving, we snorkeled and learned to free-dive and this worked great! It was amazing how our underwater trips get longer and longer and deeper and deeper. Who would have thought we could learn to go 13 m deep and stay underwater for over a minute with a single breath of air? As the proposals we wrote weren’t accurate anymore, we changed the plans and adjusted our goals to the new potential. We found lionfish to work within the shallower areas (up to 15m depth) where we used our free-dive skills to locate and film them. Being on this island was no holiday, we worked hard. We did the preparations for data collection, e.g. laying grids with pebbles for each location and surveying there. Then most went back to the Netherlands, and MSc student Davide and I stayed behind for the second month. Working with the two of us limited us in the number of surveys we could perform and in the total amount of collected data. We had to make the practical decisions ourselves, which were sometimes challenging. But because of good teamwork and all the preparations, we were able to collect the data and film the lionfish at sunset and identify them for the next day, before going out again. When we had our weekly day off, we did all the touristy things, we explored the island, visited several cities and, not surprisingly, we still went to the sea to swim, snorkel, or even SCUBA dive privately. In total, I’ve been there for seven weeks, and this has brought me so much. Not only in terms of general fish and marine knowledge, but I also gained a whole new perspective on the academic world, how to handle major changes, set new goals and adjust your research. I am really happy that we learned and practiced free-diving. I would say I had the most awesome bachelor thesis, I could imagine. Lastly, I would like to thank Alexander Kotrschal, Elizabeth Philips, Davide Bottacini, Ynze Kamstra and Hannah de Waele for this opportunity, the great times, and the wonderful experience.



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