Colorado Fishes Catalog

Status Categories

Indigenous: occurs in an area through natural process without involvement of people.
Exotic: “from another land,” meaning a species occurs in an area as a consequence of human
               involvement in geographic displacement, typically from another continent.

Abbreviations:

IN:   =  indigenous
          EX:   =  exotic
          UN:  =  undetermined

in      =  indigenous to a particular place
          ex     =  exotic to a particular place; typically, moved by people from an indigenous river drainage to a
                        river drainage where it did not naturally occur

AR   =  Arkansas River Drainage
CO   =  Colorado River Drainage
RE    =  Republican River Drainage
RG   =  Rio Grande Drainage
SP     =  South Platte River Drainage
SLV  =  San Luis Valley

est    =  established: occurring in the wild with a self-sustaining breeding population
fer    =  feral: escaped or released from captivity but with no wild, self-sustaining population and
                       continuing to occur only through ongoing escapes or releases
his    =  historical: through documentation known to have been stocked as game, prey, food, or bait but
                       stocking no longer occurs

Example interpretations:

            IN: SP   =              indigenous to South Platte River Drainage
IN: AR-exCO        =    indigenous to Arkansas River Drainage but exotic to Colorado River Drainage
EX: SLV-fer           =    exotic in San Luis Valley but feral because not known to be established with a self-sustaining population

American Name                              Latin Name                                  Colorado Status

21    Trout, Ohrid                               Salmo letnica                                EX: his

        Trout, Rainbow                          Oncorhynchus mykiss                   EX: AR-CO

22    Whitefish, Lake                          Coregonus clupeaformis               EX: his - CO

        Whitefish, Mountain                   Prosopium williamsoni                 IN: CO

Sculpins                                           Cottidae

        Sculpin, Mottled                         Cottus bairdi                                 IN: CO

23    Sculpin, Paiute                           Cottus beldingi                              IN: CO

Silversides                                       Atherinopsidae

24    Silversides, Mississippi               Menidia audens                             EX: his - SP

Smelts                                              Osmeridae

25    Smelt, Rainbow                          Osmerus mordax                           EX: SP

Sticklebacks                                    Gasterosteidae

        Stickleback, Brook                    Culaea inconstans                         IN: SP-exAR

26    Stickleback, Nine-spined           Pungitius pungitius                       EX: SP

Sturgeons                                        Acipenseridae

27    Sturgeon, Shovel-nosed             Scaphirhynchus platorynchus       IN: RG

Suckermouth-Catfishes                  Loricariidae

3      Sucker-mouthed Catfish             Hypostomus plecostomus              EX: fer - SLV-SP

3                                                       Otocinclus sp.                                EX: fer - SLV-SP

Suckers                                            Catostomidae

28    Buffalo, Big-mouthed                 Ictiobus cyprinellus                       UN: inRG?

29    Buffalo, Small-mouthed              Ictiobus bubalus                            UN: inRG?

30    Carpsucker, River                      Carpiodes carpio                          UN: inRE-RG-SP?

31    Quillback                                   Carpiodes cyprinus                       UN: inSP?

32    Redhorse, Short-headed            Moxostoma macrolepidotum        UN: inSP?

        Sucker, Blue-headed                  Catostomus discobolus                 IN: CO

        Sucker, Flannel-mouthed            Catostomus latipinnis                   IN: CO

        Sucker, Long-nosed                   Catostomus catostomus                IN: SP

        Sucker, Mountain                       Catostomus platyrhynchus           IN: CO

        Sucker, Razor-backed               Xyrauchen texanus                       IN: CO

        Sucker, Rio Grande                   Catostomus plebeius                     IN: RG

        Sucker, White                            Catostomus commersoni              IN: AR-RE-SP

Sunfishes                                         Centrarchidae

        Bass, Large-mouthed                 Micropterus salmoides                  EX: AR-CO

33    Bass, Rock                                Ambloplites rupestris                    EX: CO

        Bass, Small-mouthed                  Micropterus dolomieu                   EX: AR-CO

        Bass, Spotted                            Micropterus punctulatus               EX: AR

        Bluegill                                       Lepomis macrochirus                    EX: AR-CO

        Crappie, Black                           Pomoxis nigromaculatus              EX: AR-CO

        Crappie, White                          Pomoxis annularis                        EX: AR

        Pumpkinseed                             Lepomis gibbosus                          EX: AR

34    Sacramento-Perch                     Archoplites interruptus                 EX: SP

        Sunfish, Green                            Lepomis cyanellus                         IN: AR-RG-SP

        Sunfish, Orange-spotted             Lepomis humilis                            IN: AR-SP

        Sunfish, Red-eared                     Lepomis microlophus                    EX: AR

35    Warmouth                                  Lepomis gulosus                            EX: CO

Temperate-Basses                          Percichthyidae

36    Bass, White                               Morone chrysops                           EX: AR-CO-SP

36    Bass, Striped                             Morone saxatilis                           EX: AR-CO-SP

37    Perch, White                              Morone americana                        EX: ?

Trouts (see “Salmons”)

Man-Made Hybrids

        Bass, Palmetto                  ? Morone chrysops × ? Morone saxatalis           EX: AR-RE-SP

        Bass, Sunshine                  ? Morone saxatalis × ? Morone chrysops           EX: RE-SP

        Muskellunge, Tiger            Esox lucius × Esox masquinongy                         EX: AR-SP

        Saugeye                            Sander canadensis × Sander vitreus                     EX: AR

        Splake                              Salvelinus fontinalis × Salvelinus namaycush      EX: AR

        Trout, Cutbow                  Oncorhynchus clarkii × Oncorhynchus mykiss     EX: CO-RG-SP

        Trout, Tiger                       Salmo trutta × Salvelinus fontinalis                     EX: AR

Notes

1      Catfishes, Blue and Flat-headed —

2      Piranha, Red — Once sold in aquarium shops as “Red-bellied Piranha,” this species is now named “Red Piranha” by the American Fisheries Society (see Common and Scientific Names of Fishes from the United States and Canada, 5^th ed, 1991, page 103.)  People would release these “pets” into local waters, typically ponds in city parks or homeowners’ association neighborhoods, either as a prank or simply because they tired of them.  Someone fishing for urban bullheads, Common Carp, or Goldfish would occasionally catch a Piranha; and the catch would make a photo for the local newspaper.  The Red Piranha’s tropical origin makes them ill-suited to survive winters in Colorado, but they could still be problematic in an urban pond even if only for a few summer months.  Consequently, they are now illegal to buy, sell, or own within the state of Colorado.

3      Aquarium Fishes —

4      Drum, Freshwater — Introduced into Bonny Reservoir (Yuma County) in 1951 with other introductions elsewhere up to at least 1968.

5      Eel, American — A catadromus species, the American Eel breeds in the Sargasso Sea of the southwestern North Atlantic Ocean.  The young, called “elvers,” migrate into continental rivers where they spend three years maturing before returning to the ocean to breed and die.  Historically, the species migrated up rivers that emptied into the Gulf of Mexico and then up tributaries of them.  They reached Colorado at least in the Rio Grande and Arkansas River and quite likely in the Republican and South Platte as well.  Dams have obstructed all of these waterways downstream from Colorado so that the species no longer occurs in the state naturally.  However, an eel-ranching enterprise in the San Luis Valley was terminated and the captive American Eels were released into local waters where they could still be seen in the late 1980s.  If the Eels do not breed, they can live at least 70 years.

6      Gar, Long-nosed —

7      Alewife — Introduced into Williams Fork Reservoir (Grand County) in 1970.

8      Shad, American — This species was stocked into the Denver stretch of the South Platte River in 1872.  It was later stocked into the Colorado River system according to records of the U.S. Fish and Wildlife Service; I have not yet tracked down exact dates.

9      Mosquitofish, Western — Introduced into Boulder area ponds probably as early as 1975.  Since then, it has become a popular means of mosquito control and was promoted heavily as an alternative mosquito-control strategy when West Nile virus entered the state in the early 2000s.

10    Carp, Common —

11    Carp, Grass — Introduced into Cherry Creek Reservoir in 1965.  The species is from the Amur River system of eastern Asia ergo the name “White Amur” used in some fish literature.  It grows to six feet long and more than 100 pounds and has been cited as a cause of death of fishers on the Amur River.  It is vegetarian and usually stocked as a strategy to control algae.  Various factors indicated a possibly severe ecological problem if the species became established in the same manner as the Common Carp, so the Colorado Division of Wildlife implemented restrictions on where it could be stocked by private fisheries owners. 

12    Goldfish — This most familiar of aquarium fishes is often released into city ponds or other waters by people who grow tired of them.  However, it has in years past also been stocked as a catchable species for children’s fishing days.  It was introduced into Marston Reservoir in the early 1870s for reasons unknown and has since been stocked into many state waters.

13    Ide —

14    Rudd —

15    Shiner, Spot-tailed — Introduced into Quincy Reservoir in 1975 and again in 1978.

16    Tench —

17    Sauger and Walleye — Some people long thought the Sauger was indigenous to Colorado and the Walleye exotic because the Sauger is more adapted to streams than to lakes whereas the Walleye is more adapted to lakes than to streams.  Ergo, one of these in the South Platte River would seem to be a Sauger.  However, range maps published in Page and Burr’s Peterson Field Guide, Freshwater Fishes, shows the Walleye dipping into northeastern Colorado and the Sauger no closer than eastern Nebraska and northern Wyoming.  Further, a Colorado Division of Wildlife paper dated 1997 specifically cites Walleye as “native” and Sauger as “nonnative.”  I have not yet seen specimen evidence or research analysis that convinces me of either.