Jonathan R. Crosswait | Geology Reports

USGS2011

Thiamine status of rainbow smelt ( Osmerus mordax ) eggs in the Great Lakes, USA

During spring 2006–2009, eggs were collected for analysis of total thiamine from gravid rainbow smelt ( Osmerus mordax ) captured in each of the Great Lakes and two other waters as references for comparison. Mean standard length (mm ± standard error) of gravid females significantly differed between sample waters, with the Atlantic Ocean population being the longest (189 ± 12.3 mm) and Lake Michigan population the shortest (122 ± 0.3 mm). Mean thiamine concentrations (nmol/g ± standard error) for single-year samples for Lake Huron, Lake Michigan, and Little Clear Pond (New York) were 9.9 ± 0.8, 3.9 ± 0.7, and 8.1 ± 2.3 nmol/g, respectively. Thiamine concentrations for multiple-year samples ranged from 1.1 to 15.6 for Lake Ontario, from 2.6 to 3.3 for Lake Erie, from 5.0 to 9.9 for Lake Superior, and from 10.9 to 13.3 for the Atlantic Ocean (Fore River). Although highly variable within populations and across years, thiamine concentrations in most spawning adults appeared to be adequate in all the waters for the years sampled except for 2006 and 2009 in Lake Ontario and 2009 in Lake Erie.

Great Lakes↗

USGS2010

Thiamine status and culture of rainbow smelt ( Osmerus mordax ) from Owasco Lake, New York

In 2005, 2008, and 2009, eggs were collected for analysis of total thiamine fiom 2, 58, and 30 gravid rainbow smelt ( Osmerus mordax ) captured in Edgewater Creek, Owasco Lake, New York, respectively. Mean egg thiamine concentrations (nmollg i standard error) in 2005, 2008, and 2009 were 6.0 ± 1.8, 13.3 ± 0.5, and 14.9 ± 0.2, respectively. Eggs from three more females in 2009 were manually spawned, fertilized, and incubated in the laboratory until they hatched on day 11. The mean thiamine concentration in these eggs was 2.7 ± 0.3 nmol/g. To detect possible thiamine deficiency, on day 12 larvae from each female were divided into two groups and immersed in either static culture water alone or the same water with 5,000 mg/L thiamine for 6 hrs, after which they were held as six individual groups and fed twice daily starting on day 23 until all control larvae had died on day 29. Thiamine treatment significantly ( P <0.00l) increased survival of unfed larvae between days 15 and 18 and fed larvae between days 24 and 29 ( P <0.05). While most smelt captured in 2008 and 2009 contained adequate egg thiamine, some produced eggs low in thiamine, resulting in increased mortality of their fry, which was reduced by treatment with thiamine.

New York↗