Zebrafish has been a staple in preclinical biomedical research for over three decades, offering the ability to study hundreds of individuals simultaneously and record whole-brain activity in living animals. However, one limitation of using zebrafish in research is their social nature as a schooling species, which can influence their behavior when studied in isolation. This inherent social tendency could skew research results, prompting researchers to seek out a more solitary species for study.
Enter the paradise fish, a territorial and solitary species that offers a unique set of behaviors for researchers to explore. Comparative experiments between zebrafish and paradise fish have revealed some striking differences in behavior. While zebrafish tend to benefit from the presence of their peers when exploring new environments, paradise fish exhibit confidence and efficiency in investigating novel areas even when alone, often outperforming their zebrafish counterparts.
A recent study published in the journal Communications Biology showcases the findings of researchers from ELTE and HUN-REN IEM who have been investigating the behaviors of these two fish species. Lead author Zoltán K. Varga, a postdoctoral neuroscientist, explains that paradise fish outperform zebrafish not due to being faster or more curious, but because of their unique strategy of ‘alternation.’ This strategy involves always swimming towards unexplored areas, indicating the use of working memory, a behavior more commonly observed in mammals rather than fish.
By developing a systematic comparative framework to evaluate sociability, anxiety, and cognition in both zebrafish and paradise fish, the researchers have found that these two species offer complementary opportunities to study brain function. While zebrafish are well-suited for examining social behavior, paradise fish may hold the key to understanding solitary problem-solving and memory mechanisms.
Interestingly, paradise fish have been a subject of scientific study before, particularly at ELTE’s Department of Ethology under the guidance of Professor Vilmos Csányi. Now, modern neuroscience is rediscovering the potential hidden in this “forgotten” fish, shedding light on the species-specific differences in skills and strategies exhibited by solitary and schooling fish species.
In conclusion, the research conducted by Zoltán K. Varga and his colleagues highlights the importance of recognizing and leveraging the unique characteristics of different fish species for neuroscience and pharmacological research. By understanding and utilizing these species-specific differences, researchers can gain valuable insights into brain function and behavior.
