Adult Stage

Background to Lake Sturgeon Adult Stage

Adult Sturgeon Images

Lake sturgeon have no scales but are covered by five rows of bony scutes on their back and sides.  Lake sturgeon have a low reproductive rate and may not begin to spawn until they are 15-25 years old.  Male lake sturgeon reach sexual maturity at 15-20 years of age, and then in the Black Lake system spawn on average every other year (Forsythe et al 2012).  Once females mature at about 20-25 years of age, they spawn on average every 3-4 years (Forsythe et al. 2012).  These characteristics have affected recovery efforts for lake sturgeon, which has been designated as a protected species throughout much of their native range.  Lake sturgeon prefer large shallow lakes and rivers and the Great Lakes shorelines.  They feed by using their protruding mouth to suction up bottom dwelling organisms like crayfish and other crustaceans as well as insect larvae (DNR narrative in Natural History Section).

 

Section of Sturgeon Fin
Section of Sturgeon Fin
Section of Sturgeon Fin

 

Length-age relationships for lake sturgeon at Black Lake and in Wisconsin. Sections of the pectoral fin can be removed and sectioned to review annuli similar to tree rings that can be used to age individuals.

 

Length vs Age Graph