We've been doing general exploration for Crayfish distribution & natural
history in Ontario for the past 35 years, and much of the knowledge of
the distribution of Crayfish in Ontario is due to our efforts.
To prototype next year's "Thirty Years Later" expedition, we plan to set
off on 10 September 2009 in a survey of places where we've found or
suspected the Crayfish Orconectes immunis in the past.
This species, historically known only from
southwest of Kingston, has begun showing up in eastern Ontario (fide
Eric Snyder), where, as a burrowing species, it has the potential,
to displace local populations of O. virilis in intermittant
streams in the flat portions of eastern Ontario, where they occupy what
is O. immunis' habitat elsewhere.
These O. virilis
have what seem to be local adaptations to deal with dry years in
temporary streams (shallow burrowing and mass aggregations under flat
rocks), so they may be rapidly displaced if O. immunis, with
their whole repertoire of burrowing and dried-out adaptations, spread
widely from the sites where they are have recently been found. Or maybe
It seems timely to revisit places where we and others have previously
found Orconectes immunis beyond its contiguous range, and to
survey intervening sites to see if it can be found elsewhere.
Frederick W. Schueler & Aleta Karstad
Bishops Mills Natural History Centre
Contact us by phone at (613)258-3107
or e-mail firstname.lastname@example.org last update - 5 Aug
2009 - fws.
Aspects of the 30-years-later project:
origins of 30-Years-Later
historic field work
this month 30 years ago
planned route for 2010
projects for 2010
field methods for 2010
teaching revisit methods
suggest a revisit
sponsors of the 30 Years project
30 Years Later home page
Thirty Years Later:
Revisiting Orconectes immunis localities Thirty
Frederick W. Schueler, Adam Zieleman & Aleta Karstad - Bishops Mills
Orconectes immunis, the Papershell or Calico Crayfish, is a
small to medium- sized crayfish that is slender and fragile looking. It
is distinguished from other Ontario Orconectes by a notch at the
base of the inner side of the dactyl of the chela. Colouring is olive-
green to brown with characteristic dorsal mottled pattern and no colour
bands on tips of chelae. It is found in slow moving streams, ponds and
lakes, marshes and roadside ditches. It can construct deep burrows and
as a result is able to survive in temporary waters. Its contiguous
distribution in central Canada is Ontario south of a line between
Kingston and the Bruce Peninsula, but scattered records north of there
may be either due to a poorly documented natural distribution, or
introductions by bait fishermen.
from Premek Hamr's account of the species).
This map shows northern sites where we or others have found
Orconectes immunis. The truncations of locality names are our
records, the "QUE_" ones are from the Québec database (from Jean
Dubé), the "L_" lakes are from Brie Edwards and Keith Somers lake
surveys, and the "PH_" sites are from Premek Hamr.
Our planned route for our revisits is to go north from Ottawa to Parc de
where we (unwittingly) took the species in 1974 before it was "known"
from Québec, to other Québec sites supplied by Jean
Dubé, and then to
the Ottawa River near Thorne, Ontario, and Témiscaming,
Québec, and to Crab Lake, south of Cartier, where
we've found O. immunis in the past. We'll then
come across Mantoulin and down the Bruce Peninsula, or home by some
other route, depending on the time things have taken, the weather, and
Crews from South Nation
Conservation will be surveying the Moose Creek (MOOSEC) site. If
anyone has extralimital records of O. immunis that
they'd like to have checked out, we'd be glad to add them to our list of