Glossary

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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
Prenatal
preceding birth
Prey
animal hunted or killed for food by another animal
Primary producer
organism that makes own food by photosynthesis and/or chemical energy and is basis of a food chain
Proboscis
elongated or protruding organ or tube-like structure located in the oral region of many animals and commonly used in feeding; in pinnepeds an enlargement of the nose
Producer
organism that produces its own food through photosynthesis
Purse seine
a type of fishing net with an open end which can be drawn up to form a bag shape to capture the fish
Purse seine
a type of fishing net with an open end which can be drawn up to form a bag shape to capture the fish
Quadrupedal
four-footed animal
Radial symmetry
symmetrical arrangement of an animal's body around a central axis
Radula
tongue-like band of teeth used by many mollusks to scrape, tear or bore
Raft
large number of animals together in the water; usually applied to birds and pinnepeds
Rasp
to scrape or rub as with a file
Recruitment
process whereby young organisms are added to an adult population
Red tide
concentrations of certain microscopic organisms, particularly dinoflagellates, that discolor surface waters, usually in coastal regions and reduce oxygen supplies to animals deeper in the water column; some may be toxic
Regeneration
ability of some organisms to renew or replace an injured or lost organ or body part
Regurgitation
casting up of incompletely digested food, usually for the feeding of young
Reptile
vertebrate animal characterized as cold-blooded and having scales
Respiration
breathing; the act of assimilating oxygen and releasing carbon dioxide and other products
Rhizomes
horizontal plants capable of producing the upward shoot and downward root of a new plant
Rhopalia
concentration of neurons and sensory organs around a jelly's bell and between lobes; contains statocysts and ocelli
Rostrum
in fish - forward projection of snout; in cetaceans - upper jaw forming part of snout or beak; in crustaceans - forward pointing spine on the carapace
Rufous
reddish; tinged with red; brownish-red
Salmonid
fish belonging to the family Salmonidae which includes salmon, trout, char, whitefish, and graylings
Salt pan
small dip in high meadows where water is stranded after the tide falls
Saltmarsh
transition area of salt tolerant plants between terrestrial and marine ecosystems that are occasionally flooded by high tides; high marsh in contrast to low marsh mudflat
Sargassum
species of brown algae that is primarily found in the Sargasso Sea
Scavenger
animal that feeds on dead plants and animals
Scrape
depression in the sand or substrate that some shorebirds birds create. The bird leans forward on its breast and scratches with its feet while rotating its body axis.
SCUBA
device that lets a diver breathe air while under water (letters stand for Self-Contained Underwater Breathing Apparatus
Scyphozoa
class of Cniderians that includes jellies with a medusa form; true jellies
Sea
subdivision of the ocean, a smaller and shallower body of water than the ocean; often semi-enclosed or marginal where between land and the ocean
Sea ice
ice inpolar egions that has formed from salt waterthat has formed from salt water
Seagrass
collective name for vascular marine flowering plants that grow in shallow waters on soft substrate
Seamount
peaked, underwater mountain rising at least 1,000m (3,280ft) above the ocean floor
Seaweed
collective name for non-vascular, non-microscopic plants that usually contain chlorophyll; commonly called algae
Secondary consumers
carnivorous animals
Sedentary
remaining in one place
Semi-altricial
developmental pattern of young birds in which the young are relatively immobile when they hatch, and are fed by the adults, but the young at birth are down-covered rather than naked.
Semidiurnal tide
tide that has two high and two low waters in each tidal day
Semiprecocial
chicks hatch with eyes open, covered with down, and able to walk; but unlike fully precocial chicks, remain in or near the nest for several weeks
Sessile
permanently attached to a substrate