- Papilla
- small bump-pike projections of tissue, plural: papillae
- Papillae
- small bump-like projections of tissue
- Paralytic shellfish poisoning (PSP)
- a harmful toxin found in mussels during the warm months of the year when mussels eat certain dinoflagellates
- Parasite
- organism that lives on or in another, at the expense of the host
- Parthenogenesis
- development of an egg that has not been fertilized by a sperm
- Pathogen
- agent that causes disease. Commonly refers to infectious microorganisms such as bacteria and fungi
- PCP
- Polychlorinated biphenyl, a broad-based organochloride pesticide that is toxic to other animals
- Pectoral
- pertaining to the chest region or anterior upper thoracic region
- Pedicellaria
- minute stalked organ in some invertebrates, especially Echinoderms, that is used for grasping, defense, and scavenging
- Pedipalp
- short leg-like appendages between the chelicerae and front legs of some animals such as tarantulas
- Pelage
- coat or covering of a mammal
- Pelagic
- pertaining to the open ocean away from coasts and continental shelf areas
- Pelt
- undressed skin (with hair or fur) of an animal
- Perennial
- (botany) plant that lasts more than two growing seasons
- Peripheral
- outermost region or parts
- Peristalsis
- rhythmic and progressive wave of muscular contraction
- Pheromone
- odor released by an organism that communicates information and stimulates a physiological or behavioral response in another individual of the same species
- Photic zone
- surface layer of an ocean or lake that is penetrated by sunlight and in which phytoplankton and algae flourish
- Photosynthesis
- process by which green plants use carbon dioxide and water to produce energy-rich organic compounds into food in the presence of chlorophyll and energy from the sunlight
- Phylogeny
- relationships of groups of organisms as reflected by their evolutionary history
- Phylum
- primary division of taxonomic classification in which organisms are grouped according to their general similarities
- Physiology
- branch of biology that deals with functions and activities of life or living matter and of the physical and chemical processes involved
- Phytoplankton
- microscopic plant plankton; includes diatoms, dinoflaggelates
- Pilings
- long, heavy timbers or beams driven into the substrate of a body of water with tops that project above the water line and support a wharf or bridge
- Pinna
- fleshy flap forming outer ear; possessed by sea lions but not seals
- Pinniped
- group of marine mammals that have wing-like feet or flippers; e.g., seals, sea lions, walrus
- Piscivores
- animals that eat fish
- Placental
- mammals in which the fetus is connected to the mother's uterus and nourished through it until birth
- Plankton
- organisms that are suspended in the water column and are unable to swim against the currents, relying on water movements for transport
- Plankton bloom
- high concentration of phytoplankton resulting from the rapid reproductive multiplication of plant material in the presence of adequate nutrients and sunlight
- Planula
- pear shaped form of larvae produced by fertilized eggs of some jellies; moves by beating hair-like cilia until it finds a solid substrate on which to settle, usually converting into a polyp in time.
- Plumage
- set of feathers of a bird
- Pneumatocyst
- gas filled cavity or float that keeps an organism buoyant in the water column; e.g., swim bladder in fish, gas bladder in plants such as giant kelp; pneumatophore
- Pneumatophore
- gas filled float; modified medusae that functions to propel a colony of jellies through the water
- Pod
- two or more cetaceans that swim and move closely
- Poikilothermic
- having an unregulated body temperature that varies with the temperature of the environment; cold-blooded
- Poison
- a toxin ingested by a vcitim by mouth, through a wound, or by mouth
- Polyandry
- a female mates with several males
- Polygamy
- mating between one individual and several others of the opposite sex
- Polygyny
- a male mates with several females
- Polymorphic
- species that occur in several distinctly different forms
- Polyp
- body form characterized by a fixed base, bag-like body, and oral/anal opening at the top surrounded by a ring of tentacles; corals, sea anemones and juvenile medusa jellies have a polyp form; may produce clone polyps by budding
- Porifera
- sponge phylum
- Posterior
- toward the tail end or rear
- Potency
- strength
- Precautionary principle
- Where there are threats of serious or irreversible damage to the environment, lack of full scientific certainty should not be used as a reason for postponing cost-effective measures to prevent environmental degradation. Permits use of a lower level proof of harm in policy-making whenever the consequences of waiting for higher levels of proof may be very costly and/or irreversible.
- Precocial
- animals in which the young are born well developed and require little to no parental care
- Predation
- act of capturing prey for food
- Predator
- animal that captures and consumes other animals
- Prehensile
- adapted for grasping or holding
