Green Sucker
Pantosteus virescens
NatureServe conservation status
Global (G-rank): GNR
State (S-rank): SNR
Utah Wildlife Action Plan status
- SGCN
External links
General information
The green sucker, Pantosteus virescens, is a large species of mountain sucker native to parts of Idaho, Wyoming, and Utah; it occurs in the Weber, Bear, and Upper Snake rivers. Originally described as a distinct species, P. virescens was eventually grouped with the closely related bluehead sucker (P. discobolus) and has only recently been recognized once again as a separate species (Snyder, 1924; Unmack et al., 2014). These are long, slender fish with broad lips; they cannot readily be distinguished from the bluehead sucker by visual inspection alone. P. virescens was once abundant in its historic range but has faced steep declines, largely due to habitat modification and the introduction of nonnative species; hybridization with native fishes also poses a threat for the long-term conservation of this species.
Species range
This species occurs in the Weber River from the Echo Reservoir Dam down stream through Ogden. Additionally populations can be found in certain streams in the Raft River and Goose Creek mountains in the very Northwest corner of the state. It is also assumed that they may occur in the Bear River in portions of Rich, Summit, and Cache counties as they occur in parts of the Bear River in neighboring Wyoming and Idaho.
Migration
The Green Sucker is known to make seasonal migrations both up and downstream where they will congregate on spawning substrate in the spring during high flows. Following spawning it is assumed that they migrate back to deep pools to ride out the warm temperatures of summer and low flows of winter. For this reason connected habitats are important to this species. UDWR biologists have observed migrating individuals traveling as far as 8 miles upstream to their spawning congregations in the Weber River.
Food habits
The Green Sucker feeds on periphyton (a mixture of microbiological life and algae found on hard surfaces like rocks) by using their specially developed mouth parts that contain a hard cartilaginous ridge to allow them to scrape at the surface of rocks.
Reproductive characteristics
Colorado River Cutthroat Trout migrate to streams with proper spawning gravel in the spring. Females will build redds and deposit eggs, which are then fertilized by males. Eggs hatch in about four to five weeks, and the fry emerge from the gravel, finding refuge in slow-moving waters.
Threats or limiting factors
The greatest threats the Green Sucker face are the damming and modification of the rivers they inhabit as well as drought. Their life history requires multiple habitat types. Barriers to migration created by dams and other water structures prevent Green sucker from moving between differeing habitat types that are required for different aspects of their life history.
Taxonomy
| Previously the Green Sucker populations were considered to be part of the Bluehead Sucker. Genetic research efforts in the 2010's have clarified the sucker species in the intermountain west and as such the Green Sucker have been separated from the closely related and similar looking Bluehead Sucker (Colorado River Basin). |