Grass Pickerel
Esox americanus vermiculatus
Esox americanus vermiculatus
The Grass Pickerel is the smallest member of the Esocidae (Pike) family in Ontario with adults growing to lengths of 15 to 30cm. The other two members of the pike family found in Ontario are the Northern Pike and Muskellunge. Currently, the Grass Pickerel is considered a subspecies of the Redfin Pickerel but recent research suggests they may be distinct species.
The anatomical characteristics shared by Esocids include an elongated, cylindrical body; small, smooth scales; a single dorsal and anal fin set far back on the body; a forked tail; a long, broad head; and large canine teeth and small teeth on the roof of the mouth and tongue.
Features that distinguish Grass Pickerel from other members of the pike family are their green back; the dark and light wavy, vertical bars across their body; a white belly; dusky to yellow-green fins; and the presence of a dark, vertical bar extending below each eye in both juvenile and adult fish.
What’s in a name?
The name “Pickerel” refers to small members of the pike family. A common point of confusion is that Walleye, the popular sport fish, are widely referred to as “Pickerel” even though they are not part of the pike family nor are they related to Grass Pickerel. Walleye are actually members of the perch family and look very different from pike. Their accepted common name, Walleye, is also descriptive as it refers to their large, silvery eyes that help them to see in low-light conditions.
This compact predator hunts by sight, either stalking its prey or waiting motionless to launch an ambush. Grass Pickerel feed mainly on fishes and crayfish, but will also eat frogs, tadpoles and aquatic insects.
Grass Pickerel are found in warm, clear, slowing-moving, heavily vegetated waters of wetlands, ponds, streams, and bays of larger lakes. In shallow areas often with mud substrate. As their name suggests, riparian and aquatic vegetation are important to Grass Pickerel – even in areas that are seasonally wet – as they use it for cover as well as spawning habitat.
Grass Pickerel are found in North America in the Great Lakes and Mississippi basins. In Canada, they are found at approximately 14 locations in southern Ontario and 1 location in southwestern Quebec. They live in coastal wetlands and tributaries of Lakes Ontario, Erie, Huron, and St. Clair as well as the Ottawa and St. Lawrence rivers.
In the Sydenham watershed and immediate surrounding area, they have been recorded in the Lower East Sydenham, Walpole Island, Little Bear Creek, and Lake St. Clair as well as other nearby tributaries. In 2018, biologists with the St. Clair Region Conservation Authority sampled three Grass Pickerel from drains in the Lake St. Clair tributaries.
Activities that result in the loss of aquatic vegetation, increased turbidity and pollution, and decreasing water levels pose some of the greatest threats to Grass Pickerel populations. These activities include the removal of riparian vegetation, shoreline development, realignment and alteration of agricultural drains, sediment loading from overland runoff and bank erosion, nutrient enrichment through fertilizer application and manure spills, and the draining of wetlands. Grass Pickerel are also threatened by the spread of invasive phragmites that outcompetes native vegetation as well as changing water temperatures and water levels due to climate change and water use.
© 2024 · St. Clair Region Conservation Authority - The Sydenham River Watershed