Leeches, Eels, & Lampreys

Leeches

Leeches are used best for catching large trout while flyfishing. These parasites live on reptiles, snails or cold-blooded fish; some live off plants and dead animals. They don’t have eyes but have a high sense of smell and touch. Their highly developed muscular system and multi-segmented body allows them to change their body form from short and fat to thin and elongated. Both ends of the leech have strong suction cups to hold on to the host or bottom structures. They can reach anywhere from 1”- 6” in length. Leeches have a wide range of color, anywhere from light crème to black, brown, gray, or olive, with lateral stripes. They may have mottled spots or markings.

Eels

Eels are primitive fish that don’t have scales. They have a snake-like appearance with a long dorsal and anal fin that connects directly into the tail. Eels have strong jaws and teeth, and a pair of pectoral fins located behind the gill openings. This primitive fish is a scavenger as well as a predator of other fish species. Eels are unusual because they spawn in salt water but live in fresh water with some still staying behind and living in salt water. They are swift, strong swimmers and prefer to live on the bottoms of lakes and streams.

Lampreys

Lampreys are blood sucking parasites that are primitive fish with cartilage skeletons and no scales. They have a round, sucking, disk mouth and a long, double, dorsal fin which attaches exactly with their tails. Just behind their heads they have a series of horizontal gill holes. Their wormlike larvae can be found in freshwater streams buried in the mud or sand bottoms. After emergence, these parasites are free swimming and are eaten by trout only until they are about 2”-8” long. Lampreys mostly attack fish as parasites. They live close to bottom structures. Their coloration varies from silvery to dirty olive or brown with a lighter side.