Differences in the Blood Cell Composition between two Ecotypes of Astyanax Mexicanus (Characid)

The research focuses on the characid Astyanax mexicanus, a key model organism for studying evolutionary ecology and medical research. It examines how cave-dwelling forms of this fish adapt to extreme conditions such as perpetual darkness and low nutrition, leading to significant morphological and physiological changes. Despite these adaptations, they can still interbreed with surface forms. Notably, the study highlights a shift in the immune response strategy of cavefish, which becomes more sensitive and adapted in environments with low parasite abundance.