Brown, W.P., J.H. Selgeby, and H.L. Collins, 1997.  Reproduction and Early Life History of Ruffe (Gymnocephalus cernuus) in the St. Louis River, U.S. Geological Survey, University of Minnesota-Duluth

Proceedings of the International Symposium on Biology and Management of Ruffe, March 21-23, 1997

Reproduction and Early Life History of Ruffe (Gymnocephalus cernuus) in the St. Louis River

Abstract
The early life history of ruffe, Gymnocephalus cernuus, was investigated in the spring of 1993 and 1994 in the St. Louis River, western Lake Superior. Ruffe had a prolonged spawning period that extended from early-May to mid-June. Peak spawning occurred in mid- to late-May when water temperatures were between 12° and 14°C. Ruffe protolarva were captured 1-2 weeks after egg deposition between mid-May and late-June and most were captured in water 0.5 m deep. Onshore-offshore movements were not observed, but diel vertical movements of larval ruffe were observed on several occasions. The greatest chance of ballast water transport of pelagic larval ruffe is between mid-May and July. This information may assist fishery managers in the development of control and management efforts; however, these efforts may be complicated because of the extended spawning and hatching period of this species.

Contact: William P. Brown, U.S. Geological Survey, Great Lakes Science Center, Lake Superior Biological Station, 2800 Lake Shore Drive, East, Ashland, Wisconsin 54806 or wbrown@paulbunyan.net
Keywords: Ruffe, Basic_biology, Ballast_water
Product Type: Publications, Conference_proceedings
User Type: Boating_and_Shipping