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thresher shark

(Encyclopedia)thresher shark, long-tailed, warm-water shark, genus Alopias. The upper fork of its tail is slender and sickle-shaped and is about equal in length to the rest of the body. This shark uses its tail str...

blenny

(Encyclopedia)blenny, common name of various species of extremely numerous small fishes belonging to the suborders Blennioidei (blennies) and Notothenioidei (Antarctic blennies). They are characterized by elongated...

yarrow

(Encyclopedia)yarrow, a plant of the genus Achillea, perennial herbs of the family Asteraceae (aster family), native to north temperate regions. Several species are cultivated as ornamentals for their flat-topped c...

fish, in zoology

(Encyclopedia)CE5 Anatomy of a ray-finned fish fish, limbless aquatic vertebrate animal with fins and internal gills. Traditionally the living fish have been divided into three class: the primitive jawless fish...

ecology

(Encyclopedia)ecology, study of the relationships of organisms to their physical environment and to one another. The study of an individual organism or a single species is termed autecology; the study of groups of ...

Colorado River storage project

(Encyclopedia)Colorado River storage project, a multipurpose plan, undertaken by the U.S. Bureau of Reclamation in 1956, to control the flow of the upper Colorado and its tributaries and to aid in the development o...

hydrothermal vent

(Encyclopedia)hydrothermal vent, crack along a rift or ridge in the deep ocean floor that spews out water heated to high temperatures by the magma under the earth's crust. Some vents are in areas of seafloor spread...

frost

(Encyclopedia)frost or hoarfrost, ice formed by the condensation of atmospheric water vapor on a surface when the temperature of the surface is below 32℉ (0℃). In the formation of frost, a gas (water vapor) is ...

caisson

(Encyclopedia)caisson kāˈsən, –sŏn [key] [Fr.,=big box], in engineering, a chamber, usually of steel but sometimes of wood or reinforced concrete, used in the construction of foundations or piers in or near a...

sulfonic acid

(Encyclopedia)sulfonic acid səlfŏnˈĭk [key], organic compound containing the functional group RSO2OH, which consists of a sulfur atom, S, bonded to a carbon atom that may be part of a large aliphatic or aromati...