© 2005 International Council for the Exploration of the Sea
Metabolic cost of feeding in Atlantic Cod (Gadus morhua) larvae using microcalorimetry
a School of Marine Science, University of Maine 5741 Libby Hall, Room 214, Orono, ME 04469, USA
b American Fisheries Society 5410 Grosvenor Lane, Bethesda, MD 20814, USA
*Correspondence to I. Hunt von Herbing: tel: +1 207 581 9019; fax: +1 207 581 4388. e-mail: ihuntvon{at}nsf.gov.
A microcalorimeter that measures total heat output (µW) was used to determine total metabolic rate (aerobic and anaerobic) and the cost of feeding (specific dynamic action, SDA) in larval Atlantic cod (Gadus morhua) from hatching to 4 weeks post-hatch at 10°C. Total heat output increased throughout development from 2.14 µW at first-feeding to 23.72 µW at 4 weeks post-hatch. SDA was determined by comparing the total heat output among unfed larvae and fed larvae simultaneously. Total heat output increased in the first 2 h after feeding with rotifers (Brachionus sp.) and Artemia, remained high for up to 10 h, was significantly higher in fed larvae than in unfed larvae, and ranged from 16.56 µW at first-feeding to 47.84 µW at 4 weeks post-hatch. The differences in total heat output between unfed and fed larvae were 14.42 µW and 24.12 µW, representing an increase in metabolic cost of feeding by a factor of 1.67 over the first 4 weeks of larval life. That the metabolic cost of feeding increased with development and remained elevated suggests that cod larvae allocate a large part of their energy budget to growth in order to meet the demands of their fast growth rates.
Keywords: Atlantic cod, larvae, specific dynamic action (SDA)
Received 13 June 2004; accepted 28 October 2005.