Recovery Strategy for the Northern Riffleshell, Snuffbox, Round Pigtoe, Mudpuppy Mussel and Rayed Bean in Canada (Final)
- Executive Summary
- I. Background: 1. Species Information – Northern Riffleshell
- I. Background: 2. Species Information – Snuffbox
- I. Background: 3. Species Information – Round Pigtoe
- I. Background: 4. Species Information – Mudpuppy Mussel
- I. Background: 5. Species Information – Rayed Bean
- I. Background: 6. Threats
- I. Background: 7. Habitat – Northern Riffleshell
- I. Background: 8. Habitat – Snuffbox
- I. Background: 9. Habitat – Round Pigtoe
- I. Background: 10. Habitat – Mudpuppy Mussel
- I. Background: 11. Habitat – Rayed Bean
- I. Background: Habitat Role
- I. Background: Importance and Feasibility
- II. Recovery : Goal, Objectives and Approaches
- II. Recovery: Potential impacts, actions completed and evaluation
- Appendix 1 – Record of Cooperation and Consultation
9. Habitat – Round Pigtoe
The Round Pigtoe typically occurs in medium to large rivers (van der Schalie 1938; Parmalee and Bogan 1998), but also may occur in lakes (Clarke 1981; Strayer and Jirka 1997). In large rivers it may be found in mud, sand and gravel, deeper than 3 m, but also occurs on sand and gravel bars (Gordon and Layzer 1989). In Lake St. Clair, the Round Pigtoe inhabits shallow (<1 m) nearshore areas with firm, sandy bottoms (Zanatta et al. 2002). In smaller rivers it is often found deeply buried in gravel, cobble and boulders, in or below riffles with moderate flows (Ortmann 1919; Parmalee and Bogan 1998).
Currently Occupied Habitat
Methods for delineating currently occupied habitat for the Round Pigtoe follow the methods described for the Northern Riffleshell.
Currently occupied habitat for the Round Pigtoe can be defined as a 50 km reach of the East Sydenham River, a 20 km portion of Bear Creek through Petrolia, a 30 km stretch of the lower Thames River from Thamesville to Wardsville (Figure 19), three small reaches on the Middle and South Thames rivers near Thamesford and London (Figure 20), a 60 km reach of the lower Grand River from Caledonia to Dunnville (Figure 21) and a large area within the Lake St. Clair delta (Figure 22).
Within the area defined under Currently Occupied Habitat only areas meeting the characteristics described below are deemed to represent habitat in need of conservation:
- permanently wetted and
- of a stream order greater than 2 (riverine population only) and
- mud, sand (< 2mm) or gravel (2-60mm)
- steady to moderate flows (riverine populations only)
- nearshore areas with firm sand or gravel substrate (Great Lakes populations).
Historically Occupied Habitat
Historically occupied habitat for the Round Pigtoe consists primarily of nearshore habitats in lakes St. Clair and Erie as well as the Detroit and Niagara rivers.
- Date Modified: