Sander canadensis

Geographic Range

Saugers are freshwater percids native to the Nearctic region. Saugers inhabit most of the continental United States, east of the Rocky Mountains and west of the Appalachian Mountains as well as several provinces in Canada. Their range includes the Missouri, Ohio, Mississippi, and Saint Lawrence River drainages, all of the Great Lakes, and many tributaries. They are found from Alberta to Manitoba in Canada. In the United States, saugers are found as far west as Wyoming and Oklahoma, and as far east as New York and Alabama.

• Biogeographic Regions
• nearctic nearctic
  • native native

Habitat

Saugers inhabit rivers and larger lakes. They prefer flowing river channels with deep, turbid water and moderate currents. Saugers are considered a cool water species, favoring water that is approximately 19.6°C. Saugers typically reside in deeper water than the closely-related walleyes , and have a highly-developed tapetum lucidum, or reflective layer in their eyes that allows them to see in this darker habitat. In one study, saugers were found between 3 and 35 meters in the Ottawa River, Ontario, while walleyes were not typically found below 12 m.

• Habitat Regions
• freshwater freshwater

• Aquatic Biomes
• lakes and ponds
• rivers and streams

Physical Description

Saugers have slender, dark-yellow to brown bodies that have large, dark saddles on their sides and white undersides. They have two separate dorsal fins. The first dorsal fin has 12 spines and the second dorsal fin has 1 to 2 spines and 18 rays. Saugers also have two pectoral fins, an anal fin that contains 2 spines and 11 to 13 rays and a forked caudal fin. They have ctenoid scales and complete lateral lines. These fish have a large, horizontal mouth and canine-like teeth used for feeding on fish as adults. Saugers are closely related to walleyes , though saugers tend to be smaller. Three key characteristics help identify walleyes and saugers in the field: first, saugers have black spots on their first dorsal fin. Walleyes lack these spots, but have a black membrane that forms a spot between the last two to three spines on their first dorsal fin. Second, saugers have a distinct, dark coloration in blotches, or saddles, which extends down most of their sides. Walleyes have much lighter vertical bars that are found on the upper portion of their sides, rarely extending below the lateral line. Finally, walleyes have a white spot at the bottom of their caudal fin. Saugers lack this spot. Additionally, saugers have scales on their cheek that are lacking in walleyes. Saugers may exhibit minimal sexual dimorphism. Adult females may be slightly larger than adult males in some populations. Other populations lack any significant difference in size.

• Other Physical Features
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• sexes alike
• female larger

Development

Saugers reach maturity after two to eight years. This is primarily dependent upon climate, often associated with latitude and the availability of prey.

Reproduction

Saugers are highly migratory fish and may travel hundreds of kilometers to spawn. They reproduce by broadcast spawning. Eggs are fertilized by males as they are released over rocks, gravel, or sand. Saugers provide no parental care and do not build nests.

• Mating System
• polygynandrous (promiscuous) polygynandrous (promiscuous)

Saugers reproduce by broadcast spawning, or releasing eggs and sperm into the water column. Spawning typically occurs at night over gravel or sand in running waters located at the heads of large tributaries or immediately below dams. Reproduction typically occurs between March and May in streams or lakes depending on the geographic location. Female saugers typically lay between 10,000 and 50,000 eggs. Eggs are semi-buoyant and are 1.3 mm in diameter on average. Eggs hatch between 9 and 21 days depending on water temperature and receive no parental care. One study demonstrated that eggs hatch after about 21 days at a water temperature of 8.3°C. Saugers may interbreed with walleyes and produce viable hybrids known as saugeyes.

• Key Reproductive Features
• seasonal breeding seasonal breeding
• sexual sexual
• fertilization fertilization
  • external external
• broadcast (group) spawning

Saugers do not provide any parental care to their eggs or young.

• Parental Investment
• no parental involvement

Lifespan/Longevity

In the wild, saugers have an expected lifespan of 2 to 13 years, depending on their habitat. Their expected lifespan typically increases from south to north throughout their range.

Behavior

Saugers are most active in situations with low levels of light. They are primarily crepuscular and nocturnal feeders. This behavior is aided by a highly-developed reflective layer behind their retina, the tapetum lucidum, which enables saugers to sight feed in low light environments. When they are active during the day, saugers are found in water with high turbidity. Saugers are one of the most migratory percids , and can travel hundreds of kilometers for spawning.

• Key Behaviors
• natatorial natatorial
• nocturnal nocturnal
• crepuscular crepuscular
• motile motile
• migratory migratory

Home Range

Saugers are a highly migratory species that can travel hundreds of kilometers to spawn. In the spring, these fish travel 5 to 350 kilometers to their spawning grounds.

Communication and Perception

Saugers detect motion and vibrations in the water with a complete lateral line. They are visual predators that often feed in low-light or turbid environments using their highly-developed tapetum lucidum, a reflective layer found behind their retinas.

• Perception Channels
• visual visual
• tactile tactile
• chemical chemical

Food Habits

Saugers consume a variety of organisms throughout their life cycle, including smaller fish, insects and other invertebrates, and crustaceans . Before they have completely absorbed their yolk sac, saugers begin feeding on zooplankton. One study indicates that saugers between 12 to 50 mm in length primarily consume Daphnia as well as larvae of other organisms. As they grow, they transition to benthic invertebrates for a short time prior to becoming piscivorous. As large juveniles and adults, saugers are almost exclusively piscivorous, primarily feeding on fish. Saugers eat a variety of fish species depending on what is available in the habitat. Based on studies of the stomach contents of adult saugers, their prey includes gizzard shad , young walleye , trout-perch , yellow perch , white bass , burbots , sunfishes , emerald shiners , and many other species. In overlapping habitats, walleyes and saugers may prefer different fish species, or saugers may feed at a greater depth than walleyes. These mechanisms reduce competition between the species.

• Primary Diet
• carnivore carnivore
  • piscivore piscivore
  • insectivore insectivore
  • eats non-insect arthropods

• Animal Foods
• fish
• insects
• aquatic crustaceans
• zooplankton zooplankton

Predation

Saugers escape predation with their cryptic, camouflage coloration. These fish are preyed upon by larger fish and birds including double-crested cormorants . Walleyes , a closely related species, are known to be preyed on by yellow perch , smallmouth bass , rainbow smelt , bullheads , burbots , and northern pike when they are small and by yellow perch, spottail shiners , stonecats , and white suckers as eggs.

• Anti-predator Adaptations
• cryptic cryptic

Ecosystem Roles

As both predators and prey, saugers have a large impact on their ecosystem. Saugers may also be parasitized by 90 different species of Protozoa , trematodes , cestodes , and nematodes . Unlike walleyes , their close relatives, saugers are much more likely to be preyed upon by nematodes and trematodes.

Economic Importance for Humans: Positive

Saugers are considered important game fish and food in many areas. While they have some commercial and recreational value, they are less valued than their relatives, walleyes .

• Positive Impacts
• food food

Economic Importance for Humans: Negative

There are no known negative effects of saugers on humans.

Conservation Status

Saugers are listed as threatened by the State of Michigan, but are abundant in other parts of their range. However, it is generally accepted that the overall sauger population is declining primarily because dams reduce the availability of their preferred large, turbid river habitat. In addition, dams may prevent migration, block access to spawning grounds, change the temperature and hydrology of rivers, and reduce sediment loads.

Other Comments

Saugers were previously classified in genus Stizostedion . They are often called "sand pickerels" or "sand pike". Walleyes and saugers can interbreed and produce hybrids known as "saugeyes". These hybrids are most often the result of a female walleye and a male sauger mating, but the opposite pairing may also occur. Some saugeyes are able to reproduce with other saugeyes, saugers, or walleyes to produce viable offspring. Saugeyes share characteristics of both walleyes and saugers, but can be identified by the black streaks (rather than spots) on their first dorsal fin. Most saugeyes originate from hatchery programs; managers raise hybrids because they grow fast and, unlike either parent species, will consume artificial foods.

Additional Links

Encyclopedia of Life

BioKIDS Critter Catalog

Contributors

Amanda Harvanek (author), University of Michigan-Ann Arbor, Lauren Sallan (editor), University of Michigan-Ann Arbor, Jeff Schaeffer (editor), University of Michigan-Ann Arbor, Leila Siciliano Martina (editor), Texas State University.

References

Barton, B. 2011. Biology, Management, and Culture of Walleye and Sauger . Bethesda, MD: American Fisheries Society.

Hobson, K., R. Knapton, W. Lysack. 1989. Population, Diet and Reproductive Success of Double-crested Cormorants Breeding on Lake Winnipegosis, Manitoba, in 1987. Colonial Waterbirds , 12:2: 191-197.

Jaeger, M., A. Zale, T. McMahon, B. Schmitz. 2005. Seasonal Movements, Habitat Use, Aggregation, Exploitation, and Entrainment of Saugers in the Lower Yellowstone River: An Empirical Assessment of Factors Affecting Population Recovery. North American Journal of Fisheries Management , 25:4: 1550-1568.

Johnson, K., D. Oberlie. 2008. Habitat Use and Movement Patterns by Adult Saugers from Fall to Summer in an Unimpounded Small-River System. North American Journal of Fisheries Management , 28/2: 360-367.

Leggett, W. 2012. Abundance, growth, and life history characteristics of sympatric walleye ( Sander vitreus ) and sauger ( Sander canadensis ) in Lake Winnipeg, Manitoba. Journal of Great Lakes Research , 38: 35-46.

2011. Biology, Management, and Culture of Walleye and Sauger . Bethesda, MD: American Fisheries Society.

1983. Fishes of Wisconsin . Madison, WI: University of Wisconsin.

Virginia Department of Game and Inland Fisheries. 2013. "Sauger ( Sander canadensis )" (On-line). Accessed November 14, 2013 at http://www.dgif.virginia.gov/wildlife/fish/details.asp?fish=010215 .

Conservation Commission of Missouri. 2013. "Sauger" (On-line). Accessed November 23, 2013 at http://mdc.mo.gov/discover-nature/field-guide/sauger .

Ohio DNR. 2013. "Sauger" (On-line). A to Z Species Guide. Accessed November 17, 2013 at http://www.dnr.state.oh.us/Home/species_a_to_z/SpeciesGuideIndex/sauger/tabid/6749/Default.aspx .

Minnesota Department of Natural Resources. 2013. "Sauger" (On-line). Fishes of Minnesota: Fact Sheets. Accessed December 09, 2013 at http://www.dnr.state.mn.us/fish/sauger.html .

2014. "Sauger" (On-line). Montana Fish, Wildlife & Parks. Accessed November 14, 2013 at http://fwp.mt.gov/education/angler/mayClub/sauger.html .