COSEWIC assessment and update status report on the Salish Sucker in Canada 2002
- Assessment Summary
- Executive Summary
- SPECIES INFORMATION
- POPULATION SIZES AND TRENDS
- LIMITING FACTORS AND THREATS
- SPECIAL SIGNIFICANCE OF THE SPECIES
- EXISTING PROTECTION OR OTHER STATUS DESIGNATIONS
- SUMMARY OF STATUS REPORT
- TECHNICAL SUMMARY
- LITERATURE CITED
- BIOGRAPHICAL SUMMARY OF CONTRACTOR
- AUTHORITIES CONSULTED
- COLLECTIONS EXAMINED
Name and Classification
Species: Catostomus sp.
Evolutionary Significant Unit: Catostomussp. (Nooksack River drainage)
Common Name: Salish Sucker. Meunier Salish
The Salish sucker (Catostomus sp.; Fig. 1, 2, 3) was first found in Washington in 1947 and first observed in Canada at White Rock, British Columbia in 1950’s (McPhail 1983 & 1986). It was last seen in the Campbell River in 1976. Fortunately additional populations were found elsewhere, particularly in the Salmon River and tributaries of the Nooksack River. A species name has yet to be provided owing to the assumed allopatric distribution of Salish suckers in relation to its closest relative, the longnose sucker (McPhail and Taylor 1999). Difficulty of evaluating the populations as biological species is further exacerbated by the allopatric occurrences of each population (McPhail, 1986; Pearson, 1998a,c}. Cannings and Ptolemy 1998 emphasized McPhail’s comments that geologically, the Salish sucker is a “species in the making”. COSEWIC records the species as endangered (Campbell 1990).
Figure 1. Salish sucker from the extirpated population in Campbell River. (see Appendix 1).
McPhail and Carveth (1994) noted mophological differences between Salish and longnose suckers as did McPhail and Taylor (1999) who discussed the following:
1/ - lip length, lip width, post-pelvic length and caudal peduncle depth differ (Table 1), but were not as distinct as molecular data;
2/ - one unique Cytochrome b haplotype (#7) distinguishing them from all northwestern longnose suckers;
3/ - two unique ND2 MTDNA haplotypes (#’s 13 & 14), - # 14 was found only in the Pepin Creek population (Nooksack Drainage).
Figure 2. Distribution of Salish sucker in North America.
Figure 3. Distribution of Salish suckers (“l”) in Washington and British Columbia modified form McPhail (1986), McPhail and Taylor (1999) & Pearson (1998a; see Table 6 & 7). Eastern-most dot (“l”} lies below Harrison Lake (Pearson (2001 & 2002 pers. comm.). Hollow dots (“m”) represent closest verifiable populations of longnose suckers. Sites recorded by BC Ministry Sustainable Resources, Fisheries Data Warehouse (2001) that records Longnose suckers in lower Fraser River, Pitt Lake and Alouette River (Tables 3) do not have reliable enough data for inclusion.
|Table 1. Morphological differences between Salish and longnose suckers (McPhail and Carveth1994; McPhail & Taylor 1999)|
|Character||Salish sucker||Longnose sucker|
|Lateral line Scales||Usually fewer than 100||Usually more than 100|
|Snout shape||Snout short & blunt||Snout long & pointed|
|Mouth position||Snout barely overhangs snout||Snout clearly overhangs snout|
|Mouth length||Equal to eye diameter||Greater than eye diameter|
These differences suggest the Salish sucker represents an “Evolutionary Significant Unit” within the Catostomuscomplex, but not necessarily at the species level. McPhail and Taylor (1999) reported Salish sucker populations to be separated by 60 km of Fraser River water from the nearest known population of longnose suckers, whereas, Blood (1993) reported the distance to be 45 km. Unpublished molecular data from Miami Creek (below Harrison Lake) now confirms the first known occurrence of Salish suckers north of the Fraser River (Pearson pers. comm.2001). This closes the geographic gap between Salish and longnose suckers between 26 to 30 km (perhaps 40 creek and river miles, see Figure 3). If each population should meet, questions arise as to whether they: 1/ - behave as biological species; 2/ - historically coexisted long enough to test criteria of biological species; 3/ - different enough to minimize genetic introgression in sympatry and ecologically overcome competition for resources?
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