Glossary | P

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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