More than 35 years later, Bdellovibrio biology is undergoing a revival owing to the original, pioneering genetics work of Thomashow and colleagues (13), which has been followed up by genome sequencing and the development of new gene inactivation methods to study the function of these bacteria (32, 42, 60).
They also have five pairs of eyes. The Freshwater Leech is a parasite that feeds on the blood of fish, frogs, turtles, and mammals. It should not be confused with other leeches, most of which prey only on insects, snails, and small creatures.
The smallest leeches grow no more than 5 mm, but some big species may get to be more than 25 cm long. Many leech species have one or more pairs of eyes visible on the top of their front end. Leech species that suck blood have sharp teeth. Predatory species may have teeth, or may have only crushing jaws.