Sea hares (Aplysia californica) live in coastal environments where oxygen levels can fluctuate unpredictably. Knowing this, researchers set out to explore how these animals tolerate regular exposure to hypoxia (low oxygen) with the hope of discovering clues that could teach us how to protect humans from hypoxia-related conditions, such as stroke.

To do this, they compared offspring from two types of parents: those collected from the wild that likely experienced hypoxic conditions at some point, and those raised in a laboratory in an environment with stable oxygen. Juveniles from both groups were then exposed to six hours of low oxygen conditions over the course of 6 days, while researchers measured their growth, reflexes, and changes in gene expression.

They found that offspring from the lab-raised parents grew more slowly and had weaker responses to hypoxia. In contrast, offspring from wild parents were resistant to repeated exposure to hypoxic conditions as evidenced by normal growth and reflexes. Moreover, wild offspring seemed to come pre-programmed for survival as they had higher expression of genes involved in hypoxia tolerance, stress responses, and immune function than offspring from lab-raised parents. In fact, several of the genes that were altered in response to hypoxia in sea hares are similar to those identified in mammals that were pre-conditioned to tolerate hypoxia.

Sea hares have a simple nervous system that helps researchers examine complex neurological mechanisms that could one day inspire new targets or therapies for limiting brain damage following a stroke or other hypoxia-related injuries.

Source

Rodriguez-Casariego JA, Gillette P, Schmale M, Miller MW, Fieber LA. (2025) Experience-mediated transcriptional memory correlates with hypoxia resistance in the nervous system of the sea hare Aplysia californica. American Journal of Physiology – Regulatory, Integrative and Comparative Physiology. 329(5). https://doi.org/10.1152/ajpregu.00071.2025

• From firefighting foam to feathers: Tracking PFAS in nature
• There once was an old lady who swallowed a bullfrog…

Categories: Climate Change, Comparative Physiology, Environment, Extreme Animals, Illnesses and Injuries, Nature's Solutions, Ocean Life

Tags: American Journal of Physiology, American Physiological Society, animals, health, hypoxia, medicine, science, sea hare, stroke, wellness