Ichthyomyzon unicuspis or the Silver Lamprey is a lamprey found commonly in the Northern and Central United States and a large part of southern Canada its binomial name means "fish to suck" in Greek and "one Point" in Latin. The silver lamprey are reoprted to reach inches when first transformed and between 14 and 15 inches at maturity.

Identification

Aside from the obvious Lamprey characteristics (lack of jaw, pectoral fins etc.) the dorsal fin may be notched slightly but not divided into two separate parts, all the teeth are well developed and the mouth, when expanded is wider than the head. The teeth in the lamprey's inner circle are single pointed and there are usually 49 to 52 bands of muscle between the last gill opening and the vent. Larvae and young adults are said to be a yellow-tan with black on either side. Adults, when ready to spawn change colors to blue or blue-gray by the time they are finished spawning they are nearly black.

References

• Fishes of Missouri. Pflieger, William L. 55.
• IUCN 2007. 2007 IUCN Red List of Threatened Species. . Downloaded on 28 September 2007.