HAMES Glossary

Active Transport

The movement of materials across cell membranes and surface cell layers by processes that use metabolic energy.

Acute

A disease that has a short and usually severe course.

Aerobic

An organism, in this case a bacteria, that only grows in the presence of molecular oxygen (O2).

Ammonification

The process of ammonia production which results from protein breakdown by biological activity.

Amplitude

The extent of departure of a water quality factor from the average or mean level characteristic for the water system and conditions.

Anaerobic

An organism that only grows or a biological process that only occurs in the absence of molecular oxygen.

Anemia

A reduction in the number of red blood cells and hemoglobin in the blood of a vertebrate animal. An outcome of anemia is the oxygen carrying capacity of the blood is reduced.

Asphyxiation

Tissue anoxia resulting from suffocation.

Assimilation

Constructive metabolism or the transformation of food into living tissue of the organism.

Biomass

The weight of a particular group of organisms in a defined area.

Catabolism

Destructive metabolism or the process by living cells of breakdown of complex materials into more simple substances.

Chemical variables

Water quality factors that are chemical in nature.

Chloramines

The resultant substances from the reaction of chlorine or hypochlorous acid and ammonia. Chloramines are toxic to fish and other aquatic animals.

Chlorinity

A measure of the quantity of halides present in one kilogram of seawater.

Competitive Inhibition

The reduction of a chemical or biological reaction due to the interaction of a substance that competes for a receptor site with another substance or element.

Data

A collection of measurements or other factual information.

Delta P

The amount of needle deflection observed in a given measurement of a mechanical dissolved gas saturometer.

Denitrification

The term which refers to the reduction of nitrites and nitrates to elemental (N2) or other gaseous forms of nitrogen. Denitrification occurs in the absence of oxygen.

Diel

Fluctuations that may occur in a water quality variable over a 24 hr. period usually the day and the following night.

Direct cause

In disease causation the factor that causes the signs observed.

Disinfection

The destruction of the vegetative forms (not spores) of microorganisms usually by exposure to chemical compounds.

Dissociation equilibrium

A chemical reaction in a solution in which molecules break apart and reform with the two competitive processes in a loose equilibrium under the particular conditions of the solution.

Diurnal

Occurring during the day.

Dynamic

A condition marked by activity and change.

Encysted

An organism or structure surrounded and enclosed in a bladder, sac or cyst wall.

Fecundity

The ability to produce offspring and the measure of this ability.

Fixation

The preservation of animal or animal tissues with a chemical substance that retards or stops decay or biological breakdown.

Free chlorine residuals

The reaction products of free chlorine (Cl2) and hypochlorite ion with water, e.g. Cl- and HOCl.

Germicide

Any chemical agent that kills pathogenic microorganisms. Two examples of germicides are chlorine and iodine.

Gill filaments

The structure of the gills visible to the naked eye that are attached to the bony gill arches.

Hydrostatic pressure

The pressure exerted by water which is greatly influenced by depth.

Hypotonic

Refers to a solution that has a lower osmotic pressure than another solution with which it is being compared.

Immobolized

To have the loss of movement.

Ionized

To separate into ions. An ion is an atom or group of atoms having a positive (cation) or negative (anion) charge. Charged molecules do not pass through lipid membranes as readidly as uncharge forms.

Isotonic

Refers to a solution that has a similar osmotic pressure as another solution with which it is being compared.

Metabolic acidosis

A pathologic condition resulting from the accumulation of acid or loss of base in the tissues. The Ph of the tissues is decreased.

Methemoglobin

A reduced state of the hemoglobin molecule which has impaired ability to bind and transport oxygen. Nitrite has the ability to cause this change in fish.

Methemoglobinemia

The presence of methemoglobin in the blood.

Nitrification

The chemical process of changing ammonia to nitrate.

Nodule

A small node or raised tissue structure which is solid and can be detected by touch.

Non-selective toxicant

Any substance which is toxic to a wide range of biological systems, e.g. chlorine.

Equilibrium

The state of balance between opposing forces.

Oxidative metabolism

Metabolism that is aerobic or requires the presence of molecular oxygen.

Oxidative phosphorlation

The chemical reaction which result in the formation of ATP from ADP; oxygen serves as the electron receptor.

Oxygen stratification

The condition in which oxygen concentration differs markedly between different depths in pond water. Upper water near the surface may contain abundant oxygen while water near the bottom is oxygen depleted. Oxygen stratification usually follows temperature stratification is pond water.

Parts per thousand

One gram per 1000 mls or grams.

Phytoplankton

Microscopic algae cells found in water.

Post mortem

Refers to any event or change that occurs after death.

Rapid breathing

A sustained increase in the rate of breathing in a group of fish.

Semi-permeable membrane

A membrane which allows the passage of a solvent such as water but not certain dissolved substances.

Sluggish

A behavioral sign of fish characterized by inactivity, slow movement and decreased response to stimulation.

Standing crop

The weight of a particular group of organisms in a defined area; same as biomass.

Subclinical

The occurrence of a disease in the early stages where detection can only be made with the use of a laboratory test or microscopic procedure. Also,the occurrence of a disease before overt, clinical signs have developed.

Systemic

Refers to any condition that affects the whole body. In bacterial infection of fish, the organism has spread throughout the body usually via the blood vascular system.

Thermal stratification

The condition in which oxygen temperature differs markedly between upper and lower depths which occurs in pond water that is not well mixed. Surface water will be warmer relative to deeper water. Thermal and oxygen stratification may occur together.

Unionized

A molecule with a neutral charge. These molecules tend to diffuse rapidly through lipid membranes.

Volatilization

To change or cause to change into a vapor, e.g. a gaseous state.

Water quality factors

Physical, chemical and biological factors which contribute to a healthy environment for aquatic animals and plants.

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