Initial Observations on Thiamine Hydrochloride Treatment of Eggs of Landlocked Fall Chinook Salmon

Abstract

Abstract Eggs of landlocked fall chinook salmon Oncorhynchus tshawytscha from Lake Oahe, South Dakota, were treated with standing-bath thiamine hydrochloride at 250 and 1,000 mg/L beginning at water hardening (1 h) and continuing during transport (4 h). Biologically insignificant increases (1–2%) in embryo survival from eyed egg to hatch were observed for both of the thiamine treatment concentrations compared with nontreated controls, but no differences were observed in percent survival to the eyed stage, hatch, swim-up, or 28 d after swim-up. Egg thiamine concentrations ranged from 2.85 to 16.14 nmol/g of wet tissue in the control eggs. These results were probably influenced by unanticipated dietary shifts of adult salmon during an unusual year of very low availability of rainbow smelt Osmerus mordax. Neither thiamine hydrochloride treatment significantly elevated egg thiamine concentrations, but the detection of relatively small amounts of thiamine uptake was probably hindered by measurement variation. ...