- Palaeocopida
- pars incisiva
- parthenogenesis
- pathogen
- pectinate
- pelagic
- peripheral part
- peritrophic membrane
- pH value
- phylogeny
- phylum
- physico-chemical
- phytoplankton
- pilose
- planktivore
- plankton
- plumose
- podomere
- population
- pore
- posterior
- processus mamillaris
- procoxale
- prokaryote
- protocerebrum
- protopodite
- protuberance
- proximal