Paradise fish (Macropodus opercularis) as a complementary translational model for emotional and cognitive function

Area of Science:

• Behavioral neuroscience
• Comparative psychology
• Vertebrate physiology

Background:

• Zebrafish are widely used in physiological screening but their social behavior complicates individual behavioral assays.
• Solitary species may offer advantages for specific types of behavioral research.

Purpose of the Study:

• To evaluate paradise fish (Macropodus opercularis) as a complementary model to zebrafish (Danio rerio) for individual-based behavioral assays.
• To compare the performance of paradise fish and zebrafish in social and non-social exploratory tasks, anxiety tests, and a working memory assay.

Main Methods:

• Larval stage paradise fish and zebrafish were tested in sociability, exploratory, anxiety, and working memory tasks.
• Behavioral assays included social approach, exploration in the presence/absence of conspecifics, anxiety tests, and Y-maze tasks.
• Intra- and inter-test variability were measured to assess the repeatability of behaviors.

Main Results:

• Paradise fish exhibited no social approach and their exploration was unaffected by conspecifics, unlike zebrafish.
• Social isolation did not impact paradise fish anxiety test performance.
• Paradise fish demonstrated more consistent and repeatable exploratory and risk-avoidance behaviors compared to zebrafish.
• Paradise fish showed high arm alternation in Y-maze tasks, indicating advanced working memory.

Conclusions:

• Paradise fish are suitable for individual-based behavioral assays due to their solitary nature and consistent behavior.
• Zebrafish remain preferable for social behavioral tasks.
• Paradise fish provide a valuable complementary model system for vertebrate behavioral research.