Crayfish are common, and often encountered, but seldom recognized as species, even by naturalists who know all the birds and
wildflowers of their area and most of the fish and amphibians.
Having obtained a copy of Crocker & Barr's 'Crayfish of Ontario' soon after he came to the University of Toronto, Fred began collecting crayfish as an alternate subject in his search for stream salamanders.
Since then, we have mapped the range of cambarus bartonii in New Brunswick and the spread of the invasive orconectes rusticus in Lake of the Woods in 1976, and made many other improvements to knowledge of crayfish distribution in Canada. Aleta painted all the Ontario species in watercolour, and with these illustrations, the Toronto Zoo published 'Ontario Crayfish Identification Guide' in 2008. We continue to document the ranges of crayfish as encountered, including the spread of hybrid invasives into the mudpuppy habitat of Kemptville Creek.