1. Jawless and Toothy: Lampreys are the only surviving lineage of jawless vertebrates. Unlike most fish, they have no jaws, instead possessing a round, sucking mouth with rows of sharp teeth.
2. Eel-like Body: Their long, slender bodies are eel-like, lacking paired fins and scales. They have a single dorsal fin running along their back and a small caudal fin (tail fin).
3. Parasitic Lifestyle: Many lampreys are parasitic, attaching themselves to other fish using their sucker-like mouths. They then use their rasping teeth to bore into their host's flesh and feed on their blood and bodily fluids.
4. No Bones, Just Cartilage: Unlike most fish with bony skeletons, lampreys have a cartilaginous skeleton. This means their internal framework is made of a flexible, rubbery material rather than hard bone.
5. Primitive Features: Lampreys are considered among the most primitive of all vertebrates. They possess a simple, tube-like heart and lack a distinct stomach, suggesting a close evolutionary link to the earliest vertebrates.
6. Anadromous Migration: Many lampreys are anadromous, meaning they live in the sea but migrate to freshwater rivers to spawn. This is similar to salmon, but lampreys lack the "salmon run" phenomenon, where they die after spawning.
7. Separate Larval Stage: Lampreys have a larval stage known as an ammocoete. These larvae are filter feeders and live buried in the sediment of rivers for several years before transforming into adults.
8. Unique Reproduction: Unlike most fish, lampreys do not lay eggs in nests. They create burrows in the riverbed and deposit their eggs inside, leaving them to develop on their own.
9. Diverse Habitats: While some lampreys are parasitic and live in saltwater, others are non-parasitic and spend their entire lives in freshwater.
10. Conservation Concerns: Some lamprey species face threats due to habitat loss, pollution, and overfishing.
These unique features set lampreys apart from other fish and make them an intriguing and important part of the aquatic ecosystem.