Donald Tillitt, PhD (Former Employee)
Science and Products
Filter Total Items: 215
Influence of thiamine deficiency on Lake Trout larval growth, foraging, and predator avoidance Influence of thiamine deficiency on Lake Trout larval growth, foraging, and predator avoidance
Diet‐related thiamine deficiency increases the acute mortality, known as early mortality syndrome, of salmonines from some of the Great Lakes. The consequences of thiamine deficiency as measured at the egg stage for other important early life stage processes like growth, foraging efficiency, and predator avoidance that may also result in mortality, are unknown. Accordingly, we...
Authors
J.D. Fitzsimons, Scott B. Brown, B. Williston, G. Williston, Lisa R. Brown, K. Moore, Dale C. Honeyfield, Donald E. Tillitt
Behavioral response and kinetics of terrestrial atrazine exposure in American toads (bufo americanus) Behavioral response and kinetics of terrestrial atrazine exposure in American toads (bufo americanus)
Amphibians in terrestrial environments obtain water through a highly vascularized pelvic patch of skin. Chemicals can also be exchanged across this patch. Atrazine (ATZ), a widespread herbicide, continues to be a concern among amphibian ecologists based on potential exposure and toxicity. Few studies have examined its impact on the terrestrial juvenile or adult stages of toads. In the...
Authors
Mendez Storrs, D. E. Tillitt, T.A.G. Rittenhouse, R. D. Semlitsch
Widespread occurrence of intersex in black basses (Micropterus spp.) from U.S. rivers, 1995-2004 Widespread occurrence of intersex in black basses (Micropterus spp.) from U.S. rivers, 1995-2004
Intersex occurrence in freshwater fishes was evaluated for nine river basins in the United States. Testicular oocytes (predominantly male testes containing female germ cells) were the most pervasive form of intersex observed, even though similar numbers of male (n = 1477) and female (n = 1633) fish were examined. Intersex was found in 3% of the fish collected. The intersex condition was...
Authors
J.E. Hinck, V. S. Blazer, C. J. Schmitt, D. M. Papoulias, D. E. Tillitt
Environmental contaminants in freshwater fish and their risk to piscivorous wildlife based on a national monitoring program Environmental contaminants in freshwater fish and their risk to piscivorous wildlife based on a national monitoring program
Organochlorine chemical residues and elemental concentrations were measured in piscivorous and benthivorous fish at 111 sites from large U.S. river basins. Potential contaminant sources such as urban and agricultural runoff, industrial discharges, mine drainage, and irrigation varied among the sampling sites. Our objectives were to provide summary statistics for chemical contaminants and...
Authors
J.E. Hinck, C. J. Schmitt, K.A. Chojnacki, D. E. Tillitt
Egg fatty acid composition from lake trout fed two Lake Michigan prey fish species. Egg fatty acid composition from lake trout fed two Lake Michigan prey fish species.
We previously demonstrated that there were significant differences in the egg thiamine content in lake trout Salvelinus namaycush fed two Lake Michigan prey fish (alewife Alosa pseudoharengus and bloater Coregonus hoyi). Lake trout fed alewives produced eggs low in thiamine, but it was unknown whether the consumption of alewives affected other nutritionally important components. In this...
Authors
D. C. Honeyfield, J.D. Fitzsimons, D. E. Tillitt, S.B. Brown
Variations of thiaminase I activity pH dependencies among typical Great Lakes forage fish and Paenibacillus thiaminolyticus. Variations of thiaminase I activity pH dependencies among typical Great Lakes forage fish and Paenibacillus thiaminolyticus.
The source of thiaminase in the Great Lakes food web remains unknown. Biochemical characterization of the thiaminase I activities observed in forage fish was undertaken to provide insights into potential thiaminase sources and to optimize catalytic assay conditions. We measured the thiaminase I activities of crude extracts from five forage fish species and one strain of Paenibacillus
Authors
J.L. Zajicek, L. Brown, S.B. Brown, D. C. Honeyfield, J.D. Fitzsimons, D. E. Tillitt
Science and Products
Filter Total Items: 215
Influence of thiamine deficiency on Lake Trout larval growth, foraging, and predator avoidance Influence of thiamine deficiency on Lake Trout larval growth, foraging, and predator avoidance
Diet‐related thiamine deficiency increases the acute mortality, known as early mortality syndrome, of salmonines from some of the Great Lakes. The consequences of thiamine deficiency as measured at the egg stage for other important early life stage processes like growth, foraging efficiency, and predator avoidance that may also result in mortality, are unknown. Accordingly, we...
Authors
J.D. Fitzsimons, Scott B. Brown, B. Williston, G. Williston, Lisa R. Brown, K. Moore, Dale C. Honeyfield, Donald E. Tillitt
Behavioral response and kinetics of terrestrial atrazine exposure in American toads (bufo americanus) Behavioral response and kinetics of terrestrial atrazine exposure in American toads (bufo americanus)
Amphibians in terrestrial environments obtain water through a highly vascularized pelvic patch of skin. Chemicals can also be exchanged across this patch. Atrazine (ATZ), a widespread herbicide, continues to be a concern among amphibian ecologists based on potential exposure and toxicity. Few studies have examined its impact on the terrestrial juvenile or adult stages of toads. In the...
Authors
Mendez Storrs, D. E. Tillitt, T.A.G. Rittenhouse, R. D. Semlitsch
Widespread occurrence of intersex in black basses (Micropterus spp.) from U.S. rivers, 1995-2004 Widespread occurrence of intersex in black basses (Micropterus spp.) from U.S. rivers, 1995-2004
Intersex occurrence in freshwater fishes was evaluated for nine river basins in the United States. Testicular oocytes (predominantly male testes containing female germ cells) were the most pervasive form of intersex observed, even though similar numbers of male (n = 1477) and female (n = 1633) fish were examined. Intersex was found in 3% of the fish collected. The intersex condition was...
Authors
J.E. Hinck, V. S. Blazer, C. J. Schmitt, D. M. Papoulias, D. E. Tillitt
Environmental contaminants in freshwater fish and their risk to piscivorous wildlife based on a national monitoring program Environmental contaminants in freshwater fish and their risk to piscivorous wildlife based on a national monitoring program
Organochlorine chemical residues and elemental concentrations were measured in piscivorous and benthivorous fish at 111 sites from large U.S. river basins. Potential contaminant sources such as urban and agricultural runoff, industrial discharges, mine drainage, and irrigation varied among the sampling sites. Our objectives were to provide summary statistics for chemical contaminants and...
Authors
J.E. Hinck, C. J. Schmitt, K.A. Chojnacki, D. E. Tillitt
Egg fatty acid composition from lake trout fed two Lake Michigan prey fish species. Egg fatty acid composition from lake trout fed two Lake Michigan prey fish species.
We previously demonstrated that there were significant differences in the egg thiamine content in lake trout Salvelinus namaycush fed two Lake Michigan prey fish (alewife Alosa pseudoharengus and bloater Coregonus hoyi). Lake trout fed alewives produced eggs low in thiamine, but it was unknown whether the consumption of alewives affected other nutritionally important components. In this...
Authors
D. C. Honeyfield, J.D. Fitzsimons, D. E. Tillitt, S.B. Brown
Variations of thiaminase I activity pH dependencies among typical Great Lakes forage fish and Paenibacillus thiaminolyticus. Variations of thiaminase I activity pH dependencies among typical Great Lakes forage fish and Paenibacillus thiaminolyticus.
The source of thiaminase in the Great Lakes food web remains unknown. Biochemical characterization of the thiaminase I activities observed in forage fish was undertaken to provide insights into potential thiaminase sources and to optimize catalytic assay conditions. We measured the thiaminase I activities of crude extracts from five forage fish species and one strain of Paenibacillus
Authors
J.L. Zajicek, L. Brown, S.B. Brown, D. C. Honeyfield, J.D. Fitzsimons, D. E. Tillitt
*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government