Dodatak:Popis vrsta rakova, On
Onc
uredi- Oncaea
- Oncaeidae
- Oncaeidae
- Onceroxenidae
- Onceroxenidae
- Onceroxenus
- Onchobunops
- Onchocalanus
- Onchotelson
- Oncilorpheus
Oni
uredi- Oncinopus
- Oncopagurus
- Oniscidae
- Oniscidea incertae sedis
- Oniscophiloscia
- Oniscopsis
- Oniscus
- Onisimus
- Onisocryptus
Onk
uredi- Onkokepon
Ono
uredi- Onocryptus
Ony
uredi- Onychocamptus
Podred Onychocaudata Olesen & Richter, 2013
uredi- Cladoceromorpha Ax, 1999
- Spinicaudata Linder, 1945
Crustacea → Branchiopoda → Phyllopoda → Diplostraca
- Onychocepon
- Onychodiaptomus
- Onychomorpha
- Onychomysis
- Onycocaridella
- Onycocaridites
- Onycocaris