Genetics vs. Environment…the Age Old Question
BY DOUG ALOISI, GENOA, NFH
Egg collection crews of the USFWS and Wisconsin DNR take eggs from a Wolf River strain female. Credit: USFWS
Jenny Bailey of the La Crosse Fish Health Center was trained in the use of flow cytometry, a method to detect normal and abnormal ploidy levels in a large variety of species. With her assistance, the hatchery also is working on techniques to determine sturgeon ploidy with another technology, the particle multisizer.
Hatchery multi-sizing equipment which measures the red blood cell nucleus size to determine polyploidy. Credit: USFWS
This project is a multi-year effort, with the first year examining ploidy of parents and eggs from free flowing Wolf River strain lake sturgeon, and parents and eggs of hormone induced spawners of the St. Lawrence River strain. This year's results on the cultured progeny are still being analyzed. However, no polyploidy events were detected in the relatively small sample size of wild lake sturgeon parents. Next year’s efforts will continue to enlarge our sample size of both wild and hatchery lineage fish, while examining fry at early life stages. Many thanks to Megan Bradley and Nathan Eckert of our hatchery staff for taking on the added duties, U.C. Davis for their guidance, and the La Crosse Fish Health Center and Midwest Fisheries Center for their staff and facilities to ensure that we release the most fit fish possible to increase our restoration success.