Boo! How do Mexican cavefish escape predators? Study on escape evolution reveals vast differences in startle reflex responses between cavefish populations - Science Daily
The ability to detect threatening stimuli and initiate an escape response is critical for survival and under stringent evolutionary pressure. To detect predators, fish use a number of sensory systems including olfaction (smell) and vision, which contribute to the activation of arousal systems. Surprisingly, little is known about the neural mechanisms through which ecological perturbation shapes the evolution of escape response. When startled, do all fish respond the same way? A few fish, like Mexican cavefish, Astyanax mexicanus, have evolved in unique environments without any predators. To determine how this lack of predation impacts escape responses that are highly stereotyped across fish species, researchers from Florida Atlantic University's Charles E. Schmidt College of Science and Harriet L. Wilkes Honors College explored the tiny A. mexicanus to determine if there are evolved difference in the species. A. mexicanus exist as surface fish that inhabit rivers in Mexico and S