The chain pickerel (Esox niger) is a species of freshwater fish in the pike family (family Esocidae) of order Esociformes. The chain pickerel and the American pickerel (E. americanus) belong to the Esox genus of pike. Taxonomy French naturalist Charles Alexandre Lesueur described the chain pickerel in 1818. Its species name is the Latin word niger "black". Nicknames include the "southern pike", "grass pike", "jack", "jack fish", "gunny" and "eastern pickerel". Description The chain pickerel has a distinctive, dark, chain-like pattern on its greenish sides. There is a vertical dark marking underneath the eye, which helps to distinguish the chain pickerel from redfin pickerel (Esox americanus americanus) and grass pickerel (E. americanus vermiculatus), in which the mark curves posteriorly. Its body outline resembles that of the northern pike (E. lucius). Unlike northern pike, however, the opercles and cheeks of chain pickerel are entirely scaled. It may reach up to long only on rare occasions. The average size for chain pickerel, however, is 24 in (61 cm) and 3 lb (1 1/2 kg). (The average chain pickerel caught by fishermen is under 2 lb). It lives around 8 yr. In some places the pickerel is known as a "gunfish", "gunny" or "slime dart", due to its characteristic slime coating. A blue color morph lacking the usual reticulated pattern has been described in a New York population. Distribution Its range is along the eastern coast of North America from southern Canada to Florida, and west to Texas. On the Atlantic Coast, in Maine, New Hampshire, New Brunswick, and Nova Scotia although it is considered an invasive species in Nova Scotia, the chain pickerel extend as far as 46°N. The fish inhabits fresh and brackish water from the Mississippi Valley. It also is commonly found in Lake Michigan and the lower portion of the Great Lakes. It is considered invasive in northern areas. Habitat Chain pickerel live in a variety of habitats, including pools within creeks or rivers, lakes with vegetation cover, swamps and other wetlands. Chain pickerel are tolerant of brackish water with salinity levels of up to 22 ppt. They are also acid tolerant to a pH of 3.8. Diet Like the northern pike, the chain pickerel feeds primarily on smaller fish, until it grows large enough to ambush large fish from cover with a rapid lunge and to secure it with its sharp teeth. Chain pickerel are also known to