Unlocking the Secrets of Fish Intelligence

For over 30 years, the zebrafish has been the go-to model organism in biomedical research, thanks to its ability to allow researchers to observe brain activity in numerous individuals at once. However, there's a catch: this schooling fish’s behavior is heavily influenced by its social surroundings, which can skew experimental results when it's studied alone.

To tackle this challenging limitation, researchers from ELTE and HUN-REN IEM have turned their attention to a less social but incredibly fascinating aquatic contender: the paradise fish. With its unique behaviors, this territorial species presents an exciting alternative for comparative studies.

Stunning Discoveries in Fish Behavior

The findings from experiments involving both zebrafish and paradise fish unveiled remarkable differences in their exploration strategies. While zebrafish thrive in social settings, eagerly exploring new environments with their peers, paradise fish are fearless adventurers. They confidently investigate uncharted territories even when alone, often surpassing zebrafish in their explorative abilities.

According to Zoltán K. Varga, a postdoctoral neuroscientist at HUN-REN IEM and lead author of the study, the real kicker was how paradise fish employed a unique tactic known as 'alternation'. This means they consistently swam towards areas they hadn’t explored yet, showcasing a level of working memory previously thought to be exclusive to mammals.

Building a Comparative Framework for Fish Cognition

Alongside developmental geneticist Máté Varga from ELTE's Genetics Department and ethologist Ádám Miklósi from the Ethology Department, Varga has crafted a detailed framework to assess sociability, anxiety, and cognition across both fish species. Their groundbreaking research highlights how zebrafish and paradise fish complement each other, paving the way for deeper insights into brain functionality.

While zebrafish excel in understanding social behaviors, paradise fish might hold the key to unraveling the complexities of solitary problem-solving and memory systems.

The Resurrection of the 'Forgotten' Fish

Interestingly, paradise fish aren’t just new kids on the block. They were deeply studied decades ago at ELTE by Professor Vilmos Csányi, and now they’re making a comeback in modern neuroscience. This resurgence highlights the need to appreciate the unique contributions different species can offer to our understanding of cognition.

Varga sums it up perfectly: "We’re gaining insights into why solitary and schooling species exhibit distinct skills and strategies in various contexts, like exploring unfamiliar environments. Recognizing these species-specific differences holds significant promise for both neuroscience and pharmacological research."