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lancelet

(Encyclopedia)lancelet, name for small, fishlike lower chordate (see Chordata), also called amphioxus; it shows many affinities with the vertebrates. There are about 30 lancelet species, most belonging to the genus...

rhythm, biological

(Encyclopedia)rhythm, biological, or biorhythm, cyclic pattern of physiological changes or changes in activity in living organisms, most often synchronized with daily, monthly, or annual cyclical changes in the env...

sea urchin

(Encyclopedia)sea urchin, spherical-shaped echinoderm with movable spines covering the body. The body wall is a firm, globose shell, or test, made of fused skeletal plates and marked by regularly arranged tubercles...

commando

(Encyclopedia)commando, small, elite military raiding and assault unit or soldier. Although the word was coined in the Boer War (1899–1902), the role is as old as battles themselves. In 1940, when the British org...

fluorescence

(Encyclopedia)fluorescence flo͝orĕsˈəns [key], luminescence in which light of a visible color is emitted from a substance under stimulation or excitation by light or other forms of electromagnetic radiation or ...

Hiroshima

(Encyclopedia)Hiroshima hĭrˌōshēˈmə, hērōˈshmä [key], city, capital of Hiroshima prefectu...

Sulu Archipelago

(Encyclopedia)Sulu Archipelago so͞oˈlo͞o [key], island group, 1,086 sq mi (2,813 sq km), the Philippines, SW of Mindanao. Lying between the Celebes and Sulu seas, it includes over 900 volcanic islands and coral ...

brine shrimp

(Encyclopedia)brine shrimp, common name for a primitive crustacean that seldom reaches more than 1⁄2 in. (1.3 cm) in length and is commonly used for fish food in aquariums. Brine shrimp, which are not closely rel...

ameba

(Encyclopedia)ameba or amoeba both: əmēˈbə [key], common name for certain one-celled organisms belonging to the phylum Sarcodina of the kingdom Protista. Amebas were previously classified as members of the anim...

pompano

(Encyclopedia)pompano pŏmˈpənō [key], common name for fishes of the genus Trachinotus, members of a large and important family (Carangidae) of mackerellike fishes, abundant in warm seas around the world. They h...