Research Interests:
My general area of interest is applied fish physiology. Current research in my lab focuses on two areas. Firstly, we are studying the physiology and behaviour of triploid fish, and assessing the suitability of induced triploidy as a means to sterilize fish for aquaculture. Triploid fish are unique models for physiological research because they have larger (but fewer) cells in their tissues and organs. This allows us to examine the importance of cell size and number to basic physiological processes without having to do inter-species comparisons. Most of this research has focused on hematology, respiratory physiology and stress response, but we have also examined reproductive physiology and nutrient utilization in triploids. This work is of relevance to aquaculture and fisheries management because induced triploidy is seen as the only effective method for the mass-production of reproductively sterile fish, but triploids typically do not perform as well as normal diploids under commercial culture conditions. Our research is meant, in part, to determine the underlying reasons for the differences in performance between triploids and diploids. The second principal area of research in my lab deals with sex determination and gonadal differentiation in fish, and the use of genetic, endocrine and environmental manipulations to produce single-sex populations of fish for aquaculture. We are interested in the biochemical and physiological processes that underlie gonadal differentiation into ovaries and testes in fish, processes which are highly plastic compared to those of mammals. This work has relevance to aquaculture because frequently one sex has better production characteristics (faster growth, later maturity, production of caviar, etc.) that the other. We have collaborated extensively with industry partners on this research and, as a result, have become the world leaders in the production of all-female populations of halibut for commercial aquaculture.
Special Responsibilities:
Board of Directors (2005-2012), Huntsman Marine Science Centre
President (2010-2011), Aquaculture Association of Canada
Board of Directors (2010-2012), Canadian Aquaculture Industry Alliance
Editorial Advisory Board, Aquaculture and Acta Ichthyologica et Piscatoria
Director of Animal Care, Fredericton campus
Current Graduate Students:
Nicole Leavitt (MSc, co-supervised by Gregor Reid, UNB/DFO): Modeling growth response in urchins fed salmon feces.
Chris Small (MSc): Blood flow in the microvasculature of polyploid fish.
Nicole Nader (MSc): Cell volume regulation in polyploid erythrocytes.
Recent Graduate Students (2001-2012):
Jessica Whitehead (MSc 2012, co-supervised by Debbie Martin-Robichaud, DFO): Ovarian development and sex ratios of gynogenetic Atlantic cod (Gadus morhua).
Saranyan Pillai (PhD 2011): Comparative heat shock protein responses to temperature in diploid and triploid salmonid red blood cells.
Song Lin (MSc 2011, co-supervised by Debbie Martin-Robichaud, DFO ): Gonadal sex differentiation and hormonal sex reversal of Atlantic cod (Gadus morhua).
Charles Sacobie (PhD 2011, co-supervised by Santosh Lall, NRC): Effect of strain and diet on growth and proximate composition of triploid salmonids.
Nathaniel Feindel (MSc 2010, co-supervised by Ed Trippel, DFO): The production and reproductive biology of triploid Atlantic cod (Gadus morhua).
Heather Burke (MSc 2009, co-supervised by Santosh Lall, NRC): The response of triploid Atlantic salmon (Salmo salar) to varying levels of dietary energy and phosphorus.
Joanne Power (MSc 2009, co-supervised by Debbie Martin-Robichaud, DFO): Cage-culture characteristics of juvenile Atlantic halibut (Hippoglossus hippoglossus L.).
Marcia Chiasson (MSc, 2007): Gonadal differentiation, hormonal sex reversal and triploidy in Arctic charr, Salvelinus alpinus.
Christine Verhille (MSc, 2006): Effects of triploidy on salmonid red blood cell structure and function.
Stephanie Ratelle (MSc, 2006, co-supervised by Rick Cunjak, UNB): Ecological interactions between juvenile diploid and triploid Atlantic salmon (Salmo salar L.).
Michelle Atkins (MSc, 2005): Metabolic and hematological responses to temperature in diploid and triploid Atlantic salmon and brook trout.
Kevin Buchan (MSc, 2004, co-supervised by Debbie Martin- Robichaud, DFO): The efficacy of ozonated seawater for surface disinfection of haddock (Melanogrammus aeglefinus) eggs against piscine nodavirus.
Shawn Flynn (PhD, 2004): Sex control and reproductive biology of shortnose sturgeon, Acipenser brevirostrum LeSuere.
Harald Tvedt (PhD, 2002, co-supervised by Debbie Martin-Robichaud, DFO): Gynogenesis in Atlantic halibut (Hippoglossus hippoglossus).
Doris Smith (PhD, 2002): The reproductive physiology of diploid and triploid brook trout (Salvelinus fontinalis).
Charles Sacobie (MSc, 2001): Sexual differentiation and hormonal sex reversal in brook trout, Salvelinus fontinalis.
Recent Publications (2001-2012):
Lin, S., T.J. Benfey & D.J. Martin-Robichaud. 2012. Hormonal sex reversal in Atlantic cod, Gadus morhua. Aquaculture 364-365: 192-197.
Sacobie, C.F.D., B.D. Glebe, M.A. Barbeau, S.P. Lall & T.J. Benfey. 2012. Effect of strain and ploidy on growth performance of Atlantic salmon, Salmo salar, following seawater transfer. Aquaculture 334-337: 58-64.
Whitehead, J.A., T.J. Benfey & D.J. Martin-Robichaud. 2012. Ovarian development and sex ratio of gynogenetic Atlantic cod (Gadus morhua). Aquaculture 324–325: 174–181.
Benfey, T.J. 2011. Physiology of triploid fish. In: Encyclopedia of Fish Physiology: From Genome to Environment (A.P. Farrell, ed.), pp. 2009–2015. San Diego: Academic Press.
Feindel, N.J., T.J. Benfey & E.A. Trippel. 2011. Gonadal development of triploid Atlantic cod Gadus morhua. J. Fish Biol. 78: 1900-1912.
Tudorache, C., R.A. O’Keefe & T.J. Benfey. 2011. Optimal swimming speeds reflect preferred swimming speeds of brook charr (Salvelinus fontinalis Mitchill, 1874). Fish Physiol. Biochem. 37: 307-315.
Burke, H.A., C.F.D. Sacobie, S.P. Lall & T.J. Benfey. 2010. The effect of triploidy on juvenile Atlantic salmon (Salmo salar) response to varying levels of dietary phosphorus. Aquaculture 306: 295-301.
Feindel, N.J., T.J. Benfey & E.A. Trippel. 2010. Competitive spawning success and fertility of triploid male Atlantic cod (Gadus morhua). Aquacult. Env. Interact. 1: 47-55.
Tremblay-Bourgeois, S., N.R. Le François, R.L. Roy, T.J. Benfey & A.K. Imsland. 2010. Effect of rearing density on growth and welfare indices of juvenile spotted wolffish, Anarhichas minor (Olafsen) Aquacult. Res. 41: 1179-1189.
Tudorache, C., R.A. O’Keefe & T.J. Benfey. 2010. Flume length and post-exercise impingement affect anaerobic metabolism in brook charr Salvelinus fontinalis. Journal of Fish Biology 76: 729–733.
Tudorache, C., R.A. O’Keefe & T.J. Benfey. 2010. The effect of temperature and ammonia exposure on swimming performance of brook charr (Salvelinus fontinalis). Comparative Biochemistry and Physiology 156A: 523–528.
Adewolu, M.A. & T.J. Benfey. 2009. Growth, nutrient utilization and body composition of juvenile bagrid catfish, Chrysichthys nigrodigitatus (Actinopterygii: Siluriformes: Claroteidae), fed different dietary crude protein levels. Acta Ichthyologica et Piscatoria 39: 95-101.
Chiasson, M.A., C.S. Pelletier & T.J. Benfey. 2009. Triploidy and full-sib family effects on survival and growth in juvenile Arctic charr (Salvelinus alpinus). Aquaculture 289: 244–252.
T.J. Benfey & L.E. Bennett. 2009. Effect of temperature on heart rate in diploid and triploid brook charr, Salvelinus fontinalis, embryos and larvae. Comparative Biochemistry and Physiology 152A: 203–206.
Chiasson, M., T.J. Benfey & D.J. Martin-Robichaud. 2008. Gonadal differentiation in Atlantic cod, Gadus morhua L., and haddock, Melanogrammus aeglefinus (L.). Acta Ichthyologica et Piscatoria 38: 127-133.
Trippel, E.A., T.J. Benfey, S.R.E. Neil, N. Cross, M.J. Blanchard & F. Powell. 2008. Effects of continuous light and triploidy on growth and sexual maturation in Atlantic cod, Gadus morhua. Cybium 32(2) suppl.: 136-138.
Atkins, M.E. & T.J. Benfey. 2008. Effect of temperature on routine metabolic rate in triploid salmonids. Comparative Biochemistry and Physiology 149A: 157-161.
Chiasson, M. & T.J. Benfey. 2007. Gonadal differentiation and hormonal sex reversal in Arctic charr (Salvelinus alpinus). Journal of Experimental Zoology 307A: 527-534.
Flynn, S.R. & T.J. Benfey. 2007. Effects of dietary estradiol-17β in juvenile shortnose sturgeon, Acipenser brevirostrum, Lesueur. Aquaculture 270: 405-412.
Flynn, S.R. & T.J. Benfey. 2007. Sex differentiation and aspects of gametogenesis in shortnose sturgeon, Acipenser brevirostrum, Lesuere. Journal of Fish Biology 70: 1027- 1044.
Matsuoka, M.P., S. van Nes, Ø. Andersen, T.J. Benfey & M. Reith. 2006. Real-time PCR analysis of ovary- and brain-type aromatase gene expression during Atlantic halibut (Hippoglossus hippoglossus) development. Comparative Biochemistry and Physiology 144B: 128-135.
Buchan, K.A.H., D.J. Martin-Robichaud, T.J. Benfey, A.-M. MacKinnon & L. Boston. 2006. The efficacy of ozonated sea water for surface disinfection of haddock (Melanogrammus aeglefinus) eggs against piscine nodavirus. Aquacultural Engineering 35: 102-107.
Flynn, S.R., M. Matsuoka, M. Reith, D.J. Martin-Robichaud & T.J. Benfey. 2006. Gynogenesis and sex determination in shortnose sturgeon, Acipenser brevirostrum LeSuere. Aquaculture 253: 721-727.
Tvedt, H.B., T.J. Benfey, D.J. Martin-Robichaud, C. McGowan & M. Reith. 2006. Gynogenesis and sex determination in Atlantic halibut (Hippoglossus hippoglossus). Aquaculture 252: 573-583
Beyea, M.M., T.J. Benfey & J.D. Kieffer. 2005. Hematology and stress physiology of juvenile diploid and triploid shortnose sturgeon (Acipenser brevirostrum). Fish Phsiology and Biochemistry 31: 303-313..
Buchan, K.A.H., D.J. Martin-Robichaud & T.J. Benfey. 2005. Measurement of dissolved ozone in sea water: A comparison of methods. Aquacultural Engineering 33: 225-231.
Sacobie, C.F.D. & T.J. Benfey. 2005. Sex differentiation and early gonadal development in brook trout. North American Journal of Aquaculture 67: 181-186.
Robinson, M., S. Courtenay, T. Benfey, L. Maceda & I. Wirgin. 2004. Origin and movements of young-of-the-year striped bass in the southern Gulf of St. Lawrence, New Brunswick. Transactions of the American Fisheries Society 133: 412-426.
Schafhauser-Smith, D. & T.J. Benfey. 2003. In vitro steroid production by triploid ovarian follicles. General and Comparative Endocrinology 133: 279-286.
Hyndman, C.A., J.D. Kieffer & T.J. Benfey. 2003. Physiology and survival of triploid brook trout following exhaustive exercise in warm water. Aquaculture 221: 629-643.
Hendry, C.I., D.J. Martin-Robichaud & T.J. Benfey. 2003. Hormonal sex reversal of Atlantic halibut (Hippoglossus hippoglossus). Aquaculture 219: 769-781.
Schafhauser-Smith, D. & T.J. Benfey. 2003. The effects of long- term estradiol-17ß treatment on the growth and physiology of triploid brook trout (Salvelinus fontinalis). General and Comparative Endocrinology 131: 9-20.
Hyndman, C.A., J.D. Kieffer & T.J. Benfey. 2003. The physiological response of diploid and triploid brook trout to exhaustive exercise. Comparative Biochemistry and Physiology134A: 167-179.
Hendry, C.I., D.J. Martin-Robichaud & T.J. Benfey. 2002. Gonadal sex differentiation in Atlantic halibut. Journal of Fish Biology 60: 1431-1442.
Arndt, S.K.A., R.A. Cunjak & T.J. Benfey. 2002. Effect of summer floods and spatial-temporal scale on growth and feeding of juvenile Atlantic salmon in two New Brunswick streams. Transactions of the American Fisheries Society 131: 607-622.
Cogswell, A.T., T.J. Benfey & A.M. Sutterlin. 2002. The hematology of triploid and diploid transgenic Atlantic salmon (Salmo salar). Fish Physiology and Biochemistry 24: 271-277.
Hendry, C.I., D.J. Martin-Robichaud & T.J. Benfey. 2002. Gonadal sex differentiation in Atlantic halibut. Journal of Fish Biology 60: 1438-1449.
Schafhauser-Smith, D. & T.J. Benfey. 2002. The purification and development of a quantitative enzyme linked immunosorbent assay (ELISA) for the measurement of vitellogenin in diploid and triploid brook trout (Salvelinus fontinalis). Fish Physiology and Biochemistry 24: 287- 298.
Tvedt, H., T.J. Benfey, D.J. Martin-Robichaud & J. Power, 2001. The relationship between sperm density, spermatocrit, sperm motility and fertilization success in Atlantic halibut, Hippoglossus hippoglossus. Aquaculture 194: 191-200.
Friars, G.W., I. McMillan, V.M. Quinton, F.M. O,Flynn, S.A. McGeachy and T.J. Benfey, 2001. Family differences in relative growth of diploid and triploid Atlantic salmon (Salmo salar L.). Aquaculture 192: 23-29.
e-mail to: benfey@unb.ca
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Maintained by: casey@unb.ca
Last Update: 10 September 2012
This document: http://www.unb.ca/departs/science/biology/Faculty/Benfey.html