This 450-Million-Year-Old Bloodsucking Fish Has Been On Earth Longer Than Trees

Meet the “three-eyed” Pacific lamprey, a creature that defies time itself.

In the depths of Earth’s waterways, a peculiar creature has been silently making its presence known for eons. It’s a parasitic marvel, an eel-like entity that lacks jaws, bones, yet possesses an insatiable thirst for blood. Remarkably, this creature’s lineage stretches back further than the existence of trees and even predates the reign of dinosaurs. We’re talking about none other than the Pacific lamprey.

Having branched away from its ancestral roots in an ancient world, the Pacific lamprey boasts some extraordinary adaptations. Unlike most beings, it eschews bones and instead sports a cartilaginous “skeleton.” But what truly sets it apart is the “third eye” adorning its head—a specialized light-sensing organ.

Known scientifically as Entosphenus tridentatus, the Pacific lamprey is a true living fossil, with its origins tracing back to the Ordovician period, a staggering 450 million years ago. It derives its name from the epic odyssey it embarks upon, commencing in the freshwater rivers and streams before undertaking a migratory voyage to the Pacific Ocean.

Yet, the saga does not conclude there. Upon reaching maturity and readiness for reproduction, these lampreys must navigate back to freshwater habitats. This transformation from a marine dweller to a freshwater inhabitant is a formidable challenge, entailing various alterations in appearance and physiology to adapt to the dramatic shifts in salinity.

However, this journey isn’t a haphazard one; Pacific lampreys possess a remarkable ability—the capacity to employ chemical cues released by larval migrating lampreys to navigate back to freshwater environments. While they may return to the very waterway they were born in, there’s no guarantee, unlike Pacific salmon.

This process of transformation and navigation demands substantial sustenance, and Pacific lampreys employ a rather gruesome strategy for survival. Armed with jawless, suction-cup-like mouths, they attach themselves to the bodies of fish and marine mammals, drawing blood and bodily fluids. Their feeding leaves behind distinctive circular wounds, resembling the markings of a cookie-cutter shark or snubnosed eel. Yet, it’s essential to note that Pacific lampreys do not kill their hosts; they are parasites reliant on living hosts for sustenance.

Pacific lampreys are merely one subset of approximately 40 lamprey species that trace their origins to an ancient jawless-fish ancestor from the Ordovician period. Astonishingly, as a group, they have endured through at least four mass extinction events. These creatures play a vital role in ecosystems, serving as a source of nourishment for birds, mammals, and other fish, with their fatty flesh containing a wealth of calories. In fact, it boasts a staggering 4.1 times the amount of omega-3 fatty oils, highly sought after by us humans, as found in salmon.

Jawless, rich in lipids, and bereft of bones, the Pacific lamprey stands as a testament to nature’s enduring innovation—a testament to the wonders of evolution that have sustained it through the annals of time. This is indeed the embodiment of peak performance in the natural world.