Glossary | E

Echinoderm
any member of the Phylum Echinodermata; invertebrates that usually have a hard, spiny skeleton, radial body and water vascular system; includes sea stars, sand dollars, sea urchins, and sea cucumbers
Echolocation
process that involves the emission of sounds that reflected back from objects; aids in the animal's orientation and object location; detection of object by reflected sound
Ecology
study of the relationships of organisms to each other and to their surroundings
Ecosystem
all of the life forms in a given environment with its associated abiotic (non-living) factors
El Nino
warm, tropical surface current flowing north and south along the west coasts of North and South America that usually happens every few decades
Elasmobranch
Any member of a class of fishes that includes sharks, rays, and skatesthat have a cartilaginous skeleton and plate
Embryo
young of an organism at its very early stages of development
Endangered
plant or animal whose prospects for survival and reproduction are in immediate jeopardy
Endemic
native to a specific area, habitat, or region
Endoskeleton
internal skeleton, like the bony or cartilaginous skeletons of vertebrates
Envenomation
to sting or impregnate an organism with a toxin by means of a stinger, spine, barb, bite or poisonous tissue
Environment
sum of biological and non-biological factors to which an organism, population or community is subjected
Enzyme
a protein molecule produced by living organisms that causes a cehmical reaction to take place at a faster rate or under different conditions without itself being destroyed or altered upon completion of the reaction
Ephyra
immature medusae
Epibenthic
living on the seabed
Erosion
loss of soil due to water flow, especially in areas where native vegetation has been removed
Estivate
state of dormancy induced by high temperature; breathing and circulation slows slightly
Estrus
period of sexual receptivity in most female mammals during which mating and conception occur
Estuary
area where fresh water in the form of streams or rivers influenced by oceanic tides empties into the ocean or a coastal bay, usually forming a salt marsh
Ethology
study of animal behavior
Excluder
a plant with the ability to exclude salt from tissues, example, salty Susan
Excretor
plant able to excrete salt from their tissues. example, sea lavender
Exoskeleton
external skeleton, like the "shell" of a crab or lobster. Usually made of keratin.
Extinct
no longer in existence