I have a customer who have these in her pond (which is predominately for recreational use and water supply). She has them in her beach area. They also took a short kayak ride and a bunch of them attached to the bottom of the kayak. She baited a leech trap with raw hamburger and had no response. Any thoughts on identification or control options?
Yes, those are leaches and often introduced by turtles, waterfowl, and some amphibians moving in and out of the pond. Some leeches are 'free living' and feed on organic materials in the sediments such as decaying plant material or various worms and insects. Many of these free living leeches are sit-and-wait predators and feed on a variety of different invertebrates such as insects (gnats, mosquito larvae, water bugs), oligochaetes (both aquatic blackworms and their terrestrial cousins, the earthworms), amphipods (side swimmers), and lots of different kinds of molluscs including pond snails and freshwater clams. These predacious leeches are either engulfers (ie. they swallow their prey whole) or they are equipped with a protrusible proboscis which resembles a hypodermic needle. When not in use, the proboscis is retracted into the mouth, but when a leech has located a prey item, the proboscis pops out of the mouth and the leech uses it to spear its prey and then, once the prey is subdued, the leech uses the hollow proboscis like a soda straw and sucks up the juices of its prey.
All leeches have several natural predators: bass, catfish, panfish and larvae of a dragonfly, catfish, waterfowl and sometimes amphibians.
aka Pond Doctor & Dr. Perca Read Pond Boss Magazine - America's Journal of Pond Management
Mark, Parkland Hosp still uses them in the trauma units. They increase blood flow to injured areas. My wife used to bring them home for my son to lose.