Vertebrate Cyclostome, the european sea lamprey is a sea spawning migrator amphihaline species, which is a parasite during its growing phase at sea. After the spawning migration, lampreys couple in the upper reach of water courses, they lay their eggs, then die from physiological misery. The eggs develop sheltered into a nest until hatching of small larvae, the ammocoetes. Morphologically very different from the adults, the ammocoetes spend a several years sedentary life, being burried into the sediment. Then, they metamorphose into young lampreys which undertake their downstream migration. As soon as they enter sea water, they continue growing at the expense of several species of fishes. |