Jawless, boneless and bloodthirsty, an eel-like parasite has been writhing its way through Earth’s waterways since before dinosaurs even walked the earth. This creature, which is even older than trees, has survived until today, has been the subject of many scientific studies, and even killed the only ruler of the Middle Ages. Its name is “Pacific lamprey.”
This creature, separated from its ancestors in an ancient world, has some strange adaptations. It has no bones, instead consisting of a cartilaginous “skeleton” and has a “third eye” on the top of its head, which is actually a special light-sensing organ.
The Pacific lamprey, which can reach a size of up to 80 centimeters, can be considered a living fossil as it dates back to the Ordovician period, approximately 450 million years ago. They get their name from the incredible life journey they begin in freshwater rivers and streams before migrating to the Pacific Ocean.
But the epic migration isn’t over yet, because once they reach maturity and are ready to spawn, they must return to freshwater habitats. Transforming from a marine animal to a freshwater animal is no easy task, and a series of changes occur in the Pacific lamprey’s appearance and physiology that enable it to survive the dramatic change in salinity.
The transition from freshwater to the ocean and back again is not random, either, because Pacific lampreys have super strength; They are able to use chemical cues released by migrating larval lampreys to find their way back to freshwater life. They may return to the same waterway where they spawned, but unlike Pacific salmon, this is not guaranteed.
Such transformation and mapping skill is a demanding task, and the Pacific lamprey has a particularly poor strategy for feeding. They can bite the bodies of fish and marine mammals by using their spherical, jawless mouths like spiny suction cups.
Here, they feed on blood and body fluids, leaving a nasty sphere-shaped wound on the host’s body that resembles the wound of a cutter shark or snub-nosed eel.
Pacific lampreys are just one of about 40 species of lampreys that emerged from an ancient jawless fish ancestor during the Ordovician period, and as a group they have survived at least four mass extinction events, Live Science reports. These fish, which survive by playing a vital role in ecosystems where they are fed by birds, mammals and other fish, contain a lot of calories in their fatty meat.
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