- A -
Aberrant - deviating from the ordinary, normal, expected.
Adaptation, Biological - alteration of structure or function to suit a particular environment.
Albino - an organism with absent or deficient melanin.
Allele - either of the two paired genes affecting an inherited trait.
Alleles, Multiple - in a given population, more than two alternative forms of a gene affecting a single inherited trait.
Allopatric - related populations occupying mutually exclusive but usually adjacent geographical areas.
Amelanistic- containing no melanin
Amphibian - capable of living both in water and on land, typified by frogs, toads, and salamanders.
Amplexus - clasping of female amphibians by males in copulatory embrace. Anerythristic - without red color.
Anomaly - a deviation from the ordinary, normal, or expected
Aposematic Coloration - warning coloration.
Aquatic - living or growing in water.
Arboreal - living in trees.
Arthropod - a member of a large phylum of invertebrates, characterized by exoskeleton and jointed legs, typified by insects and spiders.
Artificial Selection - selective breeding to perpetuate desirable traits.
Autosomal Mutation - a gene change occurring in any cell other than a sex cell.
Autotomy - self-amputation, typified by tail loss of some lizards when attacked.
Axanthism - absence of yellow color, or absent or deficient xanthophore pigment metabolism.

- B -
Backcrossing - mating of an organism with a parent.
Bicephaly - possessing two heads
Bilateral - occurring on both sides of an organism.
Biological Clock - innate physiological or behavioral rhythms, synchronized with recurrent environmental factors such as time or day.

- C -
Carapace - dorsal portion of shell of turtle.
Carnivorous - meat eating.
Carotenoid - any group of red and yellow pigments, chemically similar to carotene, contained in animal fat and some plants.
Caruncle - horny spine on upper jaw of hatchling turtle, used to split jaw for hatching.
Caudal - pertaining to the tail or posterior end.
Chromosome - nuclear inclusion containing genes arranged in linear sequence.
Chromatophore - pigment cell. Congenital - present at or before birth, not necessarily inherited.
Crossing Over - exchange of corresponding segments of homologous chromosomes during meiosis, so the resulting gametes will contain chromosomes with information from both parents rather than one or the other.
Cryptic - concealing or camouflaging.
Cutaneous - pertaining to the skin.

- D -
Dendrite - a protoplasmic projection extending from a cell body.
Deoxyribonucleic Acid (DNA) - a molecule containing the genetic information of all living cells. The unit of inheritance. Gene.
Differentiation - progressive changes in cell, tissue, or organ structure and function during development, usually from simple to more complex.
Dihybrid Cross - mating of individuals heterozygous for two separate inherited traits.
Dimorphism - occurrence of two forms, distinct in color or other characteristic, among animals of the same species.
Diploid - refers to cells with pairs of homologous chromosomes (somatic cells).
Diurnal - active during daylight. Dominant - an allele that can determine the phenotype whether heterozygous or homozygous.
Dopa - 3, 4-dihydroxy-L-phenylalanine, an intermediate chemical in the synthesis of melanin.
Dorsal - the top, back, or uppermost surface of the organism.

- E -
Ectothermic (also poikilothermic or cold-blooded) - possessing no internal means for controlling body temperature.
Embryo - organism in early stages of development, before it is physiologically independent.
Embryogenesis - the development and growth of an embryo.
Endothermic (also homeothermic or warm-blooded) - having ability to maintain constant body temperature in different ambient temperatures.
Erythrophore - red Chromatophore.
Eumelanin - black or brown melanin.
External Fertilization - union of sperm and egg outside the body of either parent.

- F -
F1 - first generation offspring.
F2 - second generation offspring.
Femoral - pertaining to thighs of femur.
Flash Color - bright and conspicuous patch of color on an otherwise drab animal, displayed briefly to distract predators.

- G -
Gamete (also germ cell) - mature haploid egg or sperm.
Gene - unit of inheritance (DNA), carried on chromosomes.
Gene Pool - collectively, all of the alleles of all the genes in a population.
Genetics - study of heredity.
Genotype - genetic makeup of an organism.
Germ Cell (also Gamete) - mature haploid egg or sperm.
Gravid - pregnant.

- H -
Habitat - specific place within range in which an organism lives.
Haploid - having a single set of chromosomes (germ cell or gamete).
Hemoglobin - an iron-containing protein in red blood cells primarily for oxygen transport.
Hemotoxin - substance poisonous to or destructive of vascular system and contents.
Herbivorous - relying on vegetation for food.
Hereditary - capable of being transmitted from generation to generation.
Herpetoculture - breeding and husbandry of reptiles and amphibians.
Herpetology - study of reptiles and amphibians.
Heterozygous - having nonidentical alleles for the trait in question. Homeothermic (also endothermic or warm-blooded) - having ability to maintain constant body temperature in different ambient temperatures.
Homologous - corresponding in origin, structure, and position.
Homozygous - having identical alleles for the trait in question.
Hybrid - offspring of parents that differ in one or more heritable characters. Also refers to offspring of parents of different species.
Hypomelanistic - containing decreased amount of black and brown melanin.
Hypopigmented - containing decreased amount of pigment.

- I -
Indicator Species - a species that manifests by its presence in its habitat the existence of certain environmental conditions.
Intergrade - an intermediate form exhibiting a combination of the characteristics of two separate subspecies of the same species.
Intermedin - hormone secreted by the intermediate lobe of the pituitary gland, known to control in part the size and activity of some chromatophores.
Internal Fertilization - union of sperm and egg inside the female parent.
Iridophore - iridescent chromatophore that produces color by physical rather than metabolic methods.

- J -

- K -
Keratin - tough protein outermost layer of skin.
Keratinocyte - general term for epidermal cell.

- L -
Lateral Line Organ - series of sense organs along sides of some amphibians, probably for detection of currents, vibrations, and pressure.
Leucistic - white.
Linkage, Genetic - tendency of certain alleles to be inherited together due to the fact that they are located on the same chromosome.
Locus - position of a gene on a chromosome.

- M -
Meiosis - type of cell division in which a diploid cell divides twice, resulting in haploid germ cells.
Melanin - black or brown pigments synthesized from tyrosine.
Melanism - unusual darkening of normal pigmentation due to increased melanin.
Melanocyte - sole pigment cell of warm-blooded animals, the function of which is to synthesize melanin.
Melanocyte Stimulating Hormone (MSH) - secretion of anterior pituitary gland that stimulates synthesis of melanin.
Melanophore - chromatophore of cold-blooded vertebrates that produces melanin.
Melanosynthesis - production of melanin within melanophores or melanocytes.
Metamorphosis - transformation of one distinctive stage in life history to another, as in tadpole to frog.
Microhabitat - small restricted part of the entire range that is utilized by an organism.
Mitosis - cell division with each daughter cell identical to the parental cell.
Monohybrid Cross - breeding experiment in which parents differ in only one genetically determined trait.
Morph - visible form and structure of an organism.
Morphologic - pertaining to form and structure of an organism.
Mutagen - any substance capable of altering genetic information.
Mutation - an abrupt change in the base sequence of DNA, resulting in new genetic information. If the mutation is in a gamete, the new genetic information can be passed to the next generation.

- N -
Natural Selection - differential reproduction and survival of organisms due to environmental forces, resulting in preservation of traits most fitted for survival.
Neoteny - retention of juvenile characteristics by sexually mature individuals.
Neural Crest - dorsal portion of the neural tube (the primitive nervous system) that produces undifferentiated pigment cells and the peripheral nervous system.
Neurotoxin - poisonous substance affecting the nervous system.
Niche - that particular part of the total environment utilized by an organism.
Nocturnal - active by night.
Nonallelic genes - not coded for the same trait; not paired.

- O -
Omnivorous - including both plants and animals in diet.
Ontogenetic - development of an individual organism. Changes occurring during postembryonic life are ontogenetic.
Oviparous - reproducing by laying eggs.

- P -
Paedomorphosis - retention of juvenile characteristics by sexually mature individuals.
Parthenogenesis - mode of asexual reproduction, in which embryo develops without fertilization.
Phaeomelanin - red or yellow melanin.
Phenotype - an organism described by its external appearance.
Physiology - science dealing with function of organisms and their parts.
Piebald - spotted or patched, usually in black and white. Plastron - ventral shell of turtle.
Poikilothermic (also ectothermic or cold-blooded) - having no internal means for controlling body temperature.
Polymorphic - occurrence together of two or more distinct morphological forms of a species.
Postpartum - following birth.
Prepartum - preceding death.
Proteolytic - capable of breaking down protein.
Pteridine - class of chemicals incorporated in xanthophore pigments.

- Q -

- R -
Radio Telemetry - tracking activities of organisms by radio signals.
Recessive Gene - an allele that can determine the phenotype only when in homozygous state.

- S -
Salamander - general term for tailed amphibian.
Sex Chromosome - special sex-determining chromosome.
Sex-linked - genetic traits determined by genes carried on a sex chromosome.
Sexual Dimorphism - gender differences in characteristics.
Siblings - two or more offspring of the same parents.
Somatic Cells - all cells in an organism aside from the germ cells.
Species - group of organisms which interbreed and are reproductively isolated from all other such groups.
Stem Cell - undifferentiated cell.
Subspecies - well-defined geographic or physiologic aggregate of local population which differs from other such subdivisions of the same species.
Sympatric - having overlapping or coinciding ranges.
Systematics - the classification of organisms in a system to indicate natural relationships.

- T -
Taxonomy - scientific naming of organisms and their classification with reference to their precise position in the plant or animal kingdom.
Terrapin - any of a number of fresh water turtles, noted for basking.
Terrestrial - living on ground.
Thermoregulation - in cold-blooded animals, activity associated with external control of body temperature, such as sunning.
Tortoise - common term for some completely terrestrial turtles.
Toxic - poisonous or pertaining to poison.
Tyrosinase - the enzyme essential in synthesis of melanin.
Tyrosinase-negative Albinism - albinism due to absence of tyrosinase.
Tyrosinase-positive Albinism - albinism in animals capable of synthesizing tyrosinase, but unable to synthesize melanin.
Tyrosine - the amino acid precursor of melanin, thyroxine, and adrenalin.

- U -
Ultraviolet - radiation wavelengths just beyond the violet in the visible spectrum.
Unilateral - found only on one side.

- V -
Variant - differing from normal.
Ventral - pertaining to the under or lower surface (venter).
Vertebrate - organism having spinal or vertebral column.

- W -
Wild Type - the phenotype occurring normally or with the greatest frequency in a population.

- X -
Xanthic - yellowish.
Xanthophore - pigment cell synthesizing red, yellow, and intermediate Pteridine pigments.

- Y -

- Z -