
Email: premekhamr@trentu.ca; premek.hamr@gmail.com
Bluesky: @drecrevisse
Research Interests
Dr Premek Hamr is an adjunct faculty member in the Biology Department of Trent University in Peterborough, Ontario. He is primarily a crayfish biologist working in cooperation with Fisheries and Oceans, Canada, Ontario Ministry of Natural Resources and Forestry, BC Water, Land and Resource Stewardship, OFAH Invasive Species Awareness Program, Trent University and various biological consultants. His research centers on the distribution, conservation and life history of aquatic and terrestrial crayfish species as well as the expansion of exotic crayfishes in Canada. He has been identifying and tracking introduced species (such as the Marbled, Red swamp, White River and Rusty crayfishes) in the province and has produced a comprehensive report on the impact of invasive crayfish species in Ontario which resulted in the recent changes in provincial legislation regarding invasive species. Most recently he has co-authored the Guide to Ontario crayfishes in spring 2024 and published numerous scientific and popular articles dealing with Canadian and Australian crayfishes.
He obtained his Bachelor’s degree in Environmental Science at Concordia University in Montreal and his Master’s degree in Freshwater Ecosystems from Trent University in Peterborough. From 1985 to 1993 he resided in Hobart, Tasmania where he obtained his doctorate from the Zoology Department at the University of Tasmania. As a part of his PhD thesis, he studied the life history of the Giant Tasmanian Crayfish, a spectacular species, which reaches weights of up to 4 kg. He has also worked for the Inland Fisheries Service in Australia, the Canadian Wildlife Service in Canada. Prior to re-devoting himself to crayfish research fulltime in 2019, he lectured in Biology and Environmental Science at Trent University and Upper Canada College.
Dr Hamr is also a scientific illustrator and has contributed illustrations for reports, information sheets, online publications and posters as well as various field guides and books in Canada, US and Australia. His illustrations among others include fossils, glacial landscapes, various plants, fish ear bones, mammals, birds, amphibians, reptiles, fish, insects and of course his favourite crayfish!

Recent Publications
Edelsparre, A., McCarter, J., White, R., Aarts, M., Beauclerc, K., Choquette, J., Crowley, J., Davy, Ch., Fotherby, H., Gillingwater, S., Feltham, J., Hamr, P., Maddalena, M., Mullen, J. Quinn, J., Siu, J, Urquhart, J., Watt, C. and Pulfer, T. (in press). Forecasting species at risk conservation: Addressing recovery actions through multi-agency broad scale sampling. Ecological Solutions in press.
Hamr P. and Schryer B. The expansion of the white river crayfish (Procambarus acutus) in Ontario, Canada. (2025). Freshwater Crayfish 30 in press.
Hamr P. (2025). Red Swamp Crayfish in Ontario: Biology, Management and Impact. Report for The Biodiversity and Invasive Species Section, Ministry of Natural Resources, Peterborough Ontario. Pages 1- 48.
Hamr P. and Schryer B. (2025). Guide to Ontario’s Crayfishes. Invading Species Awareness Program & Fisheries and Oceans Canada. Second edition. P. 1-79. Updated 2nd edition. https://www.invadingspecies.com/download/guide-to-ontarios-crayfishes/#
Hamr P. (2024). The Real and Potential Impacts of Invasive Crayfish in Ontario Canada: A Review. Freshwater Crayfish 29 (1):9–22. https://doi.org/10.5869/fc.2024.v29-1.9
Filice, P., W. Budnick, R. Feagley, B. Roth, and L. Nathan. 2024. Great Lakes Almanac to Invasive Crayfish: Identification and Reporting. URL: invasivecrayfish.org/almanac (illustrations by P. Hamr).
Hamr P. and B. Schryer (2024). Guide to Ontario’s Crayfishes. With OFAH/DFO. Contributions of text and illustrations. 1st edition.
Hamr P and B. Schryer (2023). New Records of White River Crawfish (Procambarus acutus) from Ontario Canada. Crayfish News 45 (3-4): 6-9.
Hamr P. (2024). INVASIVE SPECIES RISK ASSESSMENT GUIDANCE DOCUMENT: VIRILE CRAYFISH (Faxonius virilis). BC Inter-Ministry Invasive Species Working Group. Pp. 1-20.
Hamr P., Schryer B., Lake C. (2023). Oral presentation and Abstract First record of the first wild marbled crayfish (Procambarus virginalis) population in North America/Canada and subsequent eradication efforts International Association of Astacology Symposium 24. Zagreb Croatia.
Hamr P. (2023). First Record of The Marbled Crayfish in Canada. Crayfish News 45(1-2): 1-2.
Hossie T. J. and Hamr P. (2023). Non-native White River Crayfish on Pelee Island: Habitat Use and Possible Threats to Imperilled Taxa. Poster Presentation OCTWS Conference.
Hamr P. (2022). The Life of a Rusty Crayfish (Faxonius rusticus) in Pictures. Crayfish News 44, Issue 3-4. e-ISSN: 2150-9239 (online)
Hamr P. (2022). CHIMNEY CRAYFISH RELOCATION. Report for Beacon Environmental Consulting. August 2022.
Hossie T.J. and Hamr P (2022). First Records of White River Crayfish (Procambarus acutus) in Ontario/Canada on Pelee Island, Ontario, with Notes on Other Crayfish Species Present and Their Habitats. Freshwater Crayfish 27(1): 9-16. https://doi.org/10.5869/fc.2022.v27-1.9
Hamr P and Verhoeff N (2022). The Life History of the Rusty Crayfish (Faxonius rusticus) in a Small Southern Ontario Stream. Freshwater Crayfish 27(1): 17-25. https://doi.org/10.5869/fc.2022.v27-1.17
Hamr P. (2022) Invasive Crayfish Impacts in Ontario. Report for The Biodiversity and Invasive Species Section, Fish and Wildlife Policy Branch, Ministry of Natural Resources and Forestry, Ontario. Peterborough, Ontario.
Hamr P (2021). An Update of the Classification, Status, and Distribution of Canadian Freshwater Crayfishes. Freshwater Crayfish 26(2): 119-125.
Hamr, P (2020). The Classification, Status and Distribution of Canadian Crayfishes: An Update. Crayfish News 42: 1-5.
Hamr, P., Hoel M. and K. Eales (2019). The distribution and conservation of the white colour morph of the Northern Clearwater Crayfish (Faxonius propinquus) in Lake Simcoe, Ontario, Canada. Freshwater Crayfish 24(1): 33-38. https://doi.org/10.5869/fc.2019.v24-1.33
Yaziciouglu B., Hamr P., Kozak P., Kouba A. & Niksirat H. (2016). Fine structure of the spermatozoon in three species of Cambaridae (Arthropoda: Crustacea: Decapoda) Cambarus robustus, Orconectes propinquus and Orconectes rusticus : A comparative biometrical study. Zoomorphology. PeerJ 4:e2363; DOI10.7717/peerj.2363
