The quest for the white form of the Northern Clearwater Crayfish (Orconectes propinquus) in Lake Simcoe, about an hour north of Toronto, wasn’t easy even for Hamr — a senior member of the International Crayfish Society who has researched the crustaceans for 30 years.
“It can be tricky for non-experts, but the white morph is quite distinct,” Hamr says of the crayfish first described in 1978.
The white morph has a white chela, walking legs, tail fan and underside, while the carapace is beige-pink and the abdomen is white with a very dark median stripe.
The brown morph is most common in Ontario, while the white morph doesn’t seem to occur anywhere else in North America except for around Big Bay Point on the western shore of Lake Simcoe. Hamr and Hoel’s search found it only at one locality between Big Bay Point Road in the north and Innisfil Beach in the south.
There’s an imminent risk of extinction for the white morph, according to an article written by the two UCC teachers for a recent edition of Crayfish News, as they’re at risk of being outcompeted by the invasive Rusty crayfish that’s originally from Ohio and has been found in the northern part of Lake Simcoe since 2005. A portion of the white morph’s coastal habitat has also been impacted by a large development at Friday Harbour.
Hamr and Hoel plan on conducting more follow-up surveys in the spring to establish whether any of the other white morph’s historical localities still hold populations.
“We also hope to collect females with broods to establish a large captive population in conjunction with the Ministry of Natural Resources, Metro Zoo and/or the Toronto Aquarium,” says Hamr. “I have also had an offer from the curator of invertebrates at The Carnegie Museum in Pittsburgh to cooperate and conduct DNA analysis of the white morph in comparison to other North American populations of this species.”