User:Ktschump

Reproduction/Life Cycle
Saugers generally move downstream to spawn during March-May depending on where their home locations are. They move upstream to their home locations from April-July after their spawning period is over. Saugers have been known to travel between 10 and 600 km from their home to spawning location downstream. Habitat at spawning sites are less complex and diverse than home locations. Females prefer rocky substrate and pools to deposit their eggs. As females increase in length, egg quality and fecundity increase. However, it is thought that egg production begins to decline after age 6 in female sauger. Sexual maturity is reached between 2 and 5 years old. Other measures of sexual maturity are related to size. A sauger is considered to be an adult when it reaches 250-300 mm. Upon birth, larval saugers drift downstream before developing feeding tendencies and horizontal maneuverability. Juvenile saugers tend to develop in diversion canals and backwaters until autumn when they migrate upstream to their wintering habitat. Residing in diversion canals is a large source of mortality for juvenile saugers.

Diet
Sauger feed on a variety of invertebrates and small fishes depending on the time of year and size of the sauger. Channel catfish Ictalurus punctatus and freshwater drum Pylodictus olivaris are a mid size (300-379 mm) and large (>379 mm) sauger's main food source during spring. The diet of a small sauger (200-299 mm) is slightly different than a larger sauger's. Smaller saugers generally feed on benthic invertebrates, mayfly larvae, and catfish during spring and summer. Mid-size and large saugers feed mainly on fish from spring to autumn, but their diets alter during summer. Mid-size and large saugers feed predominantly on mayfly larvae but only during summer months. Freshwater drum Aplodinotus grunniens and gizzard shad Dorosoma cepedianum are dominant food sources for saugers of all sizes during autumn. Fish accounted for over 99% of a sauger's diet during autumn. Saugers also prey on shiners during spring and summer but they do not account for a significant part of their diet. Shiners are absent from a sauger's diet in autumn probably due to their availability.

Habitat
Sauger are most likely to be found in large rivers with deep pools with depths greater than 0.6 m. Pools with depths lower than 0.6 m are not likely to yield saugers. They encounter a variety of habitats because of their migratory tendencies. They are usually found in natural rivers because they have more abundant pools and their flow regime has not been altered by dams or diversions. They are still common in impounded river systems. Diversions and dams affect habitat and spawning areas of Saugers. Saugers are usually found in areas with high turbidity, low channel slope, low stream velocity, and deep water. Saugers tend to select pools with sand and silt substrates, and habitat features that provide cover from the river current. They tend to avoid runs and riffles. They are most commonly found in pools that are at least 1.5 m deep. They can also be found in shallower pools but in lesser numbers. There have been no observed differences in habitat preference for males and females. The amount of saugers observed will increase with mean summer water temperature, maximum water depth, and mean summer alkalinity.

Conservation Issues
Saugers face many conservation issues because of migratory barriers, habitat loss, entrainment in irrigation canals, and overexploitation. Dams and diversion canals prevent spawning in upstream habitats. Altering flow regimes in rivers affects turbidity, formation of pools, and temperature. All of which are important for the timing and success of spawning saugers. Long migrations are the main reason why saugers struggle in dammed or diverted river systems. Low water levels in periods of drought are the most detrimental to sauger populations because it strands eggs during spawning and prevents larval sauger from reaching their downstream locations. High death rates that occur during spawning are related to degraded and fragmented river systems. Mortality rates in autumn are related to exploitation by fisherman.

