Petromyzontidae
The Petromyzontidae, commonly known as lampreys, are a family of jawless fishes in the order Petromyzontiformes. These eel-shaped, parasitic or predatory fish are characterized by their lack of jaws, paired fins, and scales. They are found in both marine and freshwater environments, with some species migrating between the two. Lampreys possess a unique circular mouth filled with sharp, horny teeth, which they use to attach themselves to their prey and extract blood and bodily fluids.
Common Names
Petromyzontidae are commonly known as lampreys, a name derived from the Greek words "petro" (stone) and "myzon" (sucker), reflecting their ability to cling to rocks and other surfaces.
Characteristics
Lampreys exhibit several distinctive characteristics that set them apart from other fish:
- Jawless: Lampreys lack jaws, a feature that distinguishes them from all other fish.
- Eel-shaped Body: They have elongated, serpentine bodies with a smooth, scaleless skin.
- Circular Mouth: Lampreys possess a unique circular mouth, surrounded by rows of sharp, horny teeth.
- No Paired Fins: They lack paired pectoral and pelvic fins, instead relying on a single dorsal fin and a caudal fin for propulsion.
- Cartilaginous Skeleton: Their skeleton is made of cartilage, unlike the bony skeletons of most fish.
- Parasitic or Predatory: Some lamprey species are parasitic, feeding on the blood and bodily fluids of other fish, while others are predatory, consuming small invertebrates.
Environments
Lampreys are found in a variety of aquatic environments, including:
- Marine Waters: Some species are primarily marine, residing in coastal areas and the open ocean.
- Freshwater Habitats: Others are found in freshwater lakes, rivers, and streams, often migrating between freshwater and marine environments for breeding or feeding.