dead lamprey, canadian geese.
* Note: This lamprey was not killed by TFM.
TFM
TFM stands for 3-trifluormethyl-4-nitrophenol and is the main lampricide in use today. It is a yellow-orange crystal at room temperature and is exctremely lethal to sea lamprey larvae. This feature enables TFM to be injected into streams at concentrations too low to kill or significantly harm any species of organism aside from the lamprey larvae.
In sea lampreys, TFM causes the capillaries lining the respiratory system to break, filling the gill pouches of the animal with blood and suffocating it. It causes a general enlarging of all blood vessels in the body, leading to a circulatory collapse.
This is termed a larvicide because the lampreys are most sensitve to the compound as larvae, probably partially due to the fact that lamprey larvae are filter feeders rather than predators. Also, the larvae are found in higher concentrations than the adults, making the extermination most effective at this stage in the life cycle.
Source:
Applegate, V.C. et al. "Use of 3-trifluormethyl-4-nitrophenol as a selective sea lamprey larvicide." Great Lakes Fishery Commission.
http://www.glfc.org/pubs/TechReports/Tr01.pdf Sea Lampreys
Sea Lampreys (Petromyzon marinus) are an invasive species in the Great Lakes. They are native to the Atlantic Ocean, and in the past have been considered a delicacy in other countries. Eating lampreys has not caught on in the US, due to several things: firstly that lampreys are the opposite of appetizing in appearance and secondly being the fact they do not taste good during the spawning run, which is when they are most commonly found. Lampreys have existed in the St. Lawrence River and Lake Ontario for a long time, as these bosied of water are connected to the Atlantic. However, Niagra Falls stopped the lampreys from progressing any farther until the completion of the Welland Canal in 1829. This allowed entrance into Lake Erie, and the lampreys promptly roceeded to gradually invade the remainder of the lakes.
Lampreys prey on adult fish, using their oral disc to attach themselves to a fish and then burrowing a hole in the fish's side with their tongue and teeth. Their saliva contains an anitcoagulant which keeps the wound open and bleeding nutrients into the lamprey. This stage of the lamprey life cycles lasts approximately 12-20 months, during which time each lamprey will kill up to 18 kg. or fish.
The loss of so much fish is the primary reason why lampreys are such a big problem in the Great Lakes.
http://www.glfc.org/lampcon.php
