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sculpin

(Encyclopedia)sculpin, common name for a member of the superfamily Cottoidea, bizarre fishes with large, spiny or armored heads and short, tapering bodies, found in both marine and freshwater habitats. The sculpins...

puffer

(Encyclopedia)puffer or pufferfish, common name for some tropical marine fish of the family Tetraodontidae. The puffers and their allies, including the boxfish, the porcupinefish, the triggerfish, and the marine su...

shark

(Encyclopedia)shark, member of a group of almost exclusively marine and predaceous fishes. There are about 250 species of sharks, ranging from the 2-ft (60-cm) pygmy shark to 50-ft (15-m) giants. They are found in ...

echo sounder

(Encyclopedia)echo sounder, an older instrumentation system for indirectly determining ocean floor depth. Echo sounding is based on the principle that water is an excellent medium for the transmission of sound wave...

defoliant

(Encyclopedia)defoliant, any one of several chemical compounds that, when applied to plants, can alter their metabolism, causing the leaves to drop off. In agriculture defoliants are used to eliminate the leaves of...

eutrophication

(Encyclopedia)eutrophication yo͞otrōˌfĭkāˈshən [key], aging of a lake by biological enrichment of its water. In a young lake the water is cold and clear, supporting little life. With time, streams draining i...

fossa

(Encyclopedia)fossa, carnivorous mammal, Cryptoprocta ferox, of Madagascar. The island's largest carnivore, the fossa resembles a puma in appearance and has semiretractable claws, but it is most closely related to ...

hammerhead shark

(Encyclopedia)hammerhead shark, active, surface-living shark, genus Sphyrina. Its curious head has lateral projections resembling the crossbar of a T, and its eyes and ears are located in the outer tips of the proj...

Freetown

(Encyclopedia)Freetown, city (1995 est. pop. 519,500), capital of Sierra Leone, W Sierra Leone, a port on the Atlantic Ocean. Located on the Sierra Leone peninsula, Freetown is the nation's administrative, communic...

gull

(Encyclopedia)gull, common name for an aquatic bird of the family Laridae, which also includes the tern and the jaeger. It is found near all oceans and many inland waters. Gulls are larger and bulkier than terns, a...