From CO DNR:
C. Except as provided herein, the possession of the following species, their hybrids or viable gametes is prohibited:
1. Bowfins: Amiidae.
2. Carp of the following genera: [FONT=Arial,Arial][FONT=Arial,Arial]Aristichthys [/FONT][/FONT](including but not limited to bighead carp); [FONT=Arial,Arial][FONT=Arial,Arial]Catla [/FONT][/FONT](including but not limited to catla); [FONT=Arial,Arial][FONT=Arial,Arial]Catlocarpio [/FONT][/FONT](including but not limited to giant barb); [FONT=Arial,Arial][FONT=Arial,Arial]Carrassius[/FONT][/FONT]; [FONT=Arial,Arial][FONT=Arial,Arial]Cirrhinus [/FONT][/FONT](including but not limited to mrigal); [FONT=Arial,Arial][FONT=Arial,Arial]Cyprinus[/FONT][/FONT]; [FONT=Arial,Arial][FONT=Arial,Arial]Hypophthalmichthys [/FONT][/FONT](including but not limited to silver carp and largescale silver carp); [FONT=Arial,Arial][FONT=Arial,Arial]Labeo [/FONT][/FONT](including but not limited to rohu; [FONT=Arial,Arial][FONT=Arial,Arial]Mylopharyngodon [/FONT][/FONT](including but not limited to black carp); and [FONT=Arial,Arial][FONT=Arial,Arial]Tor [/FONT][/FONT](including but not limited to mahseers). However, grass carp and common carp, including koi and goldfish may be possessed as otherwise provided for in these regulations.
3. Catfish, Walking
4. Crayfish, Rusty
5. Eel, Asian Swamp
6. Frog, Green
7. Gars: Lepisosteidae - All species.
8. Gobies: Gobiidae.
9. Mussel, Quagga
10. Mussel, Zebra
11. New Zealand mudsnail
12. Perch, White
13. Piranha: Including members of the genera Serrasalmus and Pygocentrus.
14. Rudd
15. Ruffe, Eurasian
16. Snakeheads or murrels: Members of the genera Channa, Parachanna and Ophicephalus
17. Sticklebacks: Members of the genera Apeltes, Aulorhynchus, Gasterosteus and Pungitius.
18. Tilapia: All species.
However, blue tilapia Mozambique tilapia Nile tilapia and their hybrids may be imported and possessed for fish culture and educational purposes, provided the fish and their progeny are held in facilities screened or otherwise designed to prevent their escape and are not otherwise released into waters of the state. Screen mesh size shall be no larger than 1/4" diameter. For the purposes of this regulation, "fish culture" means the raising of fish for sale as food or for export, by a licensed aquaculturist, and "educational purposes" means the raising of fish by educational facilities or for public display in public aquaria, zoos, or other similar facilities.
19. Trahira
20. Water Fleas, Fish Hook and Spiny: Cercopagis pengoi, Bythotrephes lomgimanus, and Daphnia lumholtzii.