abyss: (adj. abyssal)A deep, dark hole too big to measure (such as seemingly bottomless pit) or some really immense space below.
amphibians: A group of animals that includes frogs, salamanders and caecilians. Amphibians have backbones and can breathe through their skin. Unlike reptiles, birds and mammals, unborn or unhatched amphibians do not develop in a special protective sac called an amniotic sac.
anemone: (in zoology) Known as sea anemones, these soft, gelatinous invertebrates have a tubular body and one or more circles of venomous tentacles surrounding their mouths. These carnivorous animals tend to live glued to rocks on the seafloor, where they feed on plankton and tiny fish. Resembling a flower, an anemone can range in size from less than 2.5 centimeters (an inch) to some 1.5 meters (5 feet) across.
appendage: A finger, leg, ear, antenna or other feature that sticks out from some creature and has some apparent specific function.
biologist: A scientist involved in the study of living things.
bioluminescence: (adj. bioluminescent) The light emitted by certain animals — such as fireflies, squid and deep-sea fishes — and by some shallow-water algae.
cell: (in biology) The smallest structural and functional unit of an organism. Typically too small to see with the unaided eye, it consists of a watery fluid surrounded by a membrane or wall. Depending on their size, animals are made of anywhere from thousands to trillions of cells.
chemical: A substance formed from two or more atoms that unite (bond) in a fixed proportion and structure. For example, water is a chemical made when two hydrogen atoms bond to one oxygen atom. Its chemical formula is H2O. Chemical also can be an adjective to describe properties of materials that are the result of various reactions between different compounds.
digestive tract: The tissues and organs through which foods enter and move through the body. In people, these organs include the esophagus, stomach, intestines, rectum and anus. Foods are digested — broken down — and absorbed along the way. Any materials not used will exit as wastes (feces and urine).
excite: (in chemistry and physics) To transfer energy to one or more outer electrons in an atom. They remain in this higher energy state until they shed the extra energy through the emission of some type of radiation, such as light.
expedition: A journey (usually relatively long or over a great distance) that a group of people take for some defined purpose, such as to map a region’s plant life or to study the local microclimate.
fluoresce: (adj. fluorescent) The process of absorbing light of one wavelength (color) and reemitting as a different wavelength. That reemitted light is known as fluorescence.
liquefy: The process of turning into a liquid.
marine biologist: A scientist who studies creatures that live in ocean water, from bacteria and shellfish to kelp and whales.
platypus: Sometimes known as the duckbill, this shy Australian egg-laying mammal (Ornithorhynchus anatinus) has a streamlined body and flat bill. Its waterproof fur allows it to comfortably navigate in rivers and other waterways, where it feeds on invertebrate animals that live in the sediment. It uses electrical signals given off by the muscles of its prey to find its food. Males have a spur on the inner side of each ankle releases venom for use in their defense.
potassium: A chemical element that occurs as a soft, silver-colored metal. Highly reactive, it burns on contact with air or water with a violet flame. It is found not only in ocean water (including as part of sea salt) but also in many minerals.
prey: (n.) An organism hunted by another, often for food. (v.) To attack and eat another organism.
proboscis: A straw-like mouthpiece in bees, moths and butterflies used for sucking up liquids. The term can also be applied to an animal’s long snout (such as in an elephant).
sea: An ocean (or region that is part of an ocean). Unlike lakes and streams, seawater — or ocean water — is salty.
sea spider: Not true spiders, these are any of some 1,400 sea-dwelling arthropods that resemble real spiders. Sea spiders are part of the same arthropod family tree as true spiders, but diverged to form their own “branch” on that tree roughly half a billion years ago. Many of these species live in deep, cold water near Earth’s poles.
species: A group of similar organisms capable of producing offspring that can survive and reproduce.
spider: A type of arthropod with four pairs of legs and two main body sections (a head-thorax combination and an abdomen). Spiders often have the ability to spin threads of silk they can use to create webs or other structures.
tissue: Made of cells, it is any of the distinct types of materials that make up animals, plants or fungi. Cells within a tissue work as a unit to perform a particular function in living organisms. Different organs of the human body, for instance, often are made from many different types of tissues.
tract: A particular, well-defined area. It can be a patch of land, such as the area on which a house is located. Or it can be a bit of real estate in the body. For instance, important parts of an animal’s body will include its respiratory tract (lungs and airways), reproductive tract (gonads and hormone systems important to reproduction) and gastro-intestinal tract (the stomach and intestines — or organs responsible for moving food, digesting it, absorbing it and eliminating wastes).
trait: A characteristic feature of something. (in genetics) A quality or characteristic that can be inherited.
ultraviolet: A portion of the light spectrum that is close to violet but invisible to the human eye.
wavelength: The distance between one peak and the next in a series of waves, or the distance between one trough and the next. It’s also one of the “yardsticks” used to measure radiation. Visible light — which, like all electromagnetic radiation, travels in waves — includes wavelengths between about 380 nanometers (violet) and about 740 nanometers (red). Radiation with wavelengths shorter than visible light includes gamma rays, X-rays and ultraviolet light.