Glossary of Commonly Used Biological and Related Terms in Water and Waste Water Control* 



Acclimation — ^The process of adjusting to a change in 

 an environment. 



Adaptation — A change in the structure, form, or habit 

 of an organism resulting from a change in its environ- 

 ment. 



Aerobic Organism — An organism that thrives in the 

 presence of oxygen. 



Algae (Alga) — Simple plants, many microscopic, con- 

 taining chlorophyll. Most algae are aquatic and may 

 produce a nuisance when conditions are suitable for 

 prolific growth. 



Aloicide — A specific chemical highly toxic to algae. 

 Algicides are often applied to water to control nuisance 

 algal blooms. 



Algology — The study of algae. 



Amphipods — (see Scuds). 



Anadromous Fishes — Fishes that spend a part of their 

 life in the sea or lakes, but ascend rivers at more or 

 less regular intervals to spawn. Examples are sturgeon, 

 shad, salmon, trout, and striped bass. 



Anaerobic Organism — An organism that thrives in the 

 absence of oxygen. 



Annelids — Segmented worms, as distinguished from the 

 nonsegmented roundworms and flatworms. Most are 

 marine; however, many live in soil or fresh water. 

 Aquatic forms may establish dense populations in the 

 presence of rich organic deposits. Common examples 

 of segmented worms are earthworms, sludgeworms, 

 and leeches. 



Assimilation — The transformation of absorbed nutri- 

 ents into body substances. 



Autotrophic Organism — An organism capable of con- 

 structing organic matter from inorganic substances. 



Benthic Region — The bottom of a body of water. This 

 region supports the benthos, a type of life that not 

 only lives upon but contributes to the character of the 

 bottom. 



Benthos — Aquatic bottom-dwelling organisms. These in- 

 clude: (1) Sessile animals, such as the sponges, barna- 

 cles, mussels, oysters, some of the worms, and many 

 attached algae; (2) creeping forms, such as insects, 

 snails, and certain clams; and (3) burrowing forms, 

 which include most clams and worms. 



BioASSAY — A determination of the concentration of a 

 given material by comparison with a standard prepara- 

 tion; or the determination of the quantity necessary to 

 affect a test animal under stated laboratory condi- 

 tions. 



BiOMASS — The weight of all life in a specified unit of 

 environment or an expression of the total mass or 

 weight of a given population, both plant and animal. 



Biota — All living organisms of a region. 



Bivalve — An animal with a hinged two-valve shell; ex- 

 amples are the clam and oyster. 



Bloom — A readily visible concentrated growth or ag- 

 gregation of plankton (plant and animal). 



Blue-Green Algae — A group of algae with a blue pig- 

 ment, in addition to the green chlorophyll. A stench 

 is often associated with the decomposition of dense 

 blooms of blue-green algae in fertile lakes. 



Catadromous Fishes — Fishes that feed and grow in 

 fresh water, but return to the sea to spawn. The 

 best known example is the American eel. 



Clean Water Association — An association of orga- 

 nisms, usually characterized by many different kinds 

 (species). These associations occur in natural unpol- 

 luted environments. Because of competition, predation, 

 etc., however, relatively few individuals represent any 

 particular species. 



Coarse or Rough Fish — Those species of fish considered 

 to be of poor fighting quality when taken on tackle 

 and of poor food quality. These fish may be undesir- 

 able in a given situation, but at times may be classified 

 differently, depending upon their usefulness. Examples 

 include carp, goldfish, gar, sucker, bowfin, gizzard shad, 

 goldeneye, mooneye, and certain kinds of catfish. 



Coelenterate — A group of aquatic animals that have 

 gelatinous bodies, tentacles, and stinging cells. These 

 animals occur in great variety and abundance in the 

 sea and are represented in fresh water by a few types. 

 Examples are hydra, corrals, sea anemones, and jelly- 

 fish. 



Cold-Blooded Animals (Poikilothermic Animals) — 

 Animals that lack a temperature regulating mecha- 

 nism that offsets external temperature changes. Their 

 temperature fluctuates to a large degree with that of 

 their environment. Examples are fish, shellfish, and 

 aquatic insects. 



Consumers — Organisms that consume solid particles of 

 organic food material. Protozoa are consumers. 



Crustacea — Mostly aquatic animals with rigid outer 

 coverings, jointed appendages, and gills. Examples are 

 crayfish, crabs, barnacles, water fleas, and sow bugs. 



Daphnia (see Water Fleas). 



Dermatitis — Any inflammation of the skin. One type 

 may be caused by the penetration beneath the skin of 

 a cercaria found in water; this form of dermatitis is 

 commonly called "swimmers' itch." 



Dystrophic Lakes — Brown-water lakes with a very low 

 lime content and a very high humus content. These 

 lakes often lack nutrients. 



Ecology — 'The science of the interrelations between liv- 

 ing organisms and their environment. 



Emergent Aquatic Plants — Plants that are rooted at 

 the bottom but project above the water surface. Ex- 

 amples are cattails and bulrushes. 



Environment — The sum of all external influences and 

 conditions affecting the life and the development of an 

 organism. 



Epilimnion — ^That region of a body of water that ex- 

 tends from the surface to the thermocline and does not 

 have a permanent temperature stratification. 



Estuary — Commonly an arm of the sea at the lower end 

 of a river. Estuaries are often enclosed by land except 

 at channel entrance points. 



Eulittoral Zone — The shore zone of a body of water 

 between the limits of water-level fluctuation. 



EuPHonc Zone — The lighted region that extends ver- 

 tically from the water surface to the level at which 



* Extracted from: Geckler, J. R., K. M. Mackenthun, and W. M. Ingram. 1963. 



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