Nitrogen Excretion in Fed and Fasted Lake Sturgeon

• DOI: 10.1577/a06-086.1
• Publication Date: 2008-02-11T15:00:57Z
• Authors: Anant S Bharadwaj; Kevin L Pangle; Trent M Sutton; Paul B Brown
• Keywords: 0401 agriculture, forestry, and fisheries; 14. Life underwater; 04 agricultural and veterinary sciences

Abstract Lake sturgeon Acipenser fulvescens are imperiled throughout their native range, and hatchery-reared fish often stocked to facilitate population restoration. However, the rearing of hatchery requires knowledge nitrogenous excretion rates for efficient culture system design maintenance. Total ammonia nitrogen (TAN) urea (UN) were quantified in age-0 lake that either fasted or fed brine shrimp Artemia spp. In first experiment, three different size-classes (small [10–20 g], medium [50–65 large [100–120 g]) 5 d, excretions measured at end this period. second from low (0.5% body weight [BW] on a dry-matter basis, 4.2% BW wet-weight basis), high (1% 8.3% basis) rations Artemia. No UN was detected sturgeon. Endogenous TAN varied inversely with size. The mean endogenous rate small (37.42 mg·kg−1·d−1) significantly higher than (13.72 (6.02 fish. (117.34 (33.69 (26.29 Ration size did not affect rates, affected by ration These results suggest sturgeon, like most teleost fishes, predominantly excrete ammonia. estimates study will aid determining densities juvenile systems.