*Definitions are given in relation to map turtles. There may be other meanings for these words.


Aquaculture – the practice of raising aquatic organisms for commercial purposes i. e. turtle farmers.

Allometry – changes in body proportions or color with increasing size.

Allopatric – occurring in separate non-overlapping geographical areas, such as G. caglei is allopatric to G. versa.

Alluvial river– a type of river where the bed and banks are made up of mobile sediment or soil that have channels and floodplains, such as the Pearl River.


Bivalve – a type of aquatic mollusk (invertebrate) with a compressed body (shell) and a hinge such as clams, oysters, mussels and scallops.

Blackwater river – a type of river that flows through forested swamps and has a lot of submerged debris from rotting vegetation. The water is usually dark and molluscs are mostly unsuccessful. Megacephalic map turtles usually do not inhabit blackwater rivers and waterways.


Conspecific – belonging to the same species, such as G. p. pseudogeographica is conspecific to G. p. kohnii.

Clinal variation – gradual change of a trait over a gradient. Example: Sabine map turtles have a greater carapace length (by average) near the coast as opposed to upstream populations.

Clutch size – the number of eggs laid by a single female at one time.


Double clutching – amphibians and reptiles that produce two clutches of eggs or offspring in a single season.


Emydid – a turtle within the Family Emydidae i.e. map turtles, sliders, cooters, etc.

Epibiont – an organism that lives on top of another organism.

Epiphenomenon – a secondary symptom or byproduct of a process.




Herpetoculture – the captive husbandry and propagation of amphibians and reptiles in captivity as a hobby or for commercial purposes.

Husbandry – the care, cultivation and breeding of plants and animals in captivity.

Hypoallometric – less than equal dimensions


Isometric – having equal dimensions





Megacephaly – having a large head i.e. G. barbouri, G. ernsti, etc. in the case of female map turtles.

Mesocephaly -having a medium-shaped head i.e. G. caglei, G. versa in the case of female map turtles.

Microcephaly – having a small head i. e. G. sabinensis, G. flavimaculata in the case of female map turtles.

Molluscivorous – feeds on mollusks

Morph – a form or structure, for example having  black-eyes is a different morph of G. p. kohnii.

Morphological traits -characters of form or structure that define a morph, such as possessing a transverse bar on the chin is a morphological trait of G. caglei.

Morphology – the study of form or structure.

Morphometrics – measurable (quantitative) parameters of form or structure, such as the pigment width on the marginal scutes is one type of morphometrics.



Ontogenetic – the development or changes in an individual from egg/infant to adult.


Paraphyly –  a group that contains its last common ancestor, but not all the  descendants of that ancestor

Pheromone – a chemical produced by an individual and released into the environment for the purpose of signaling other individuals of the same species for a specific intent such as to attract mates, mark territories, or to leave a scent trail.

Phylogenetics – the evolutionary relationships within or between groups.

Phylogenetic tree – a diagram showing the evolutionary relationships within or between groups with line segments and branching.

Phylogeny – The relationships of groups of organisms according to their evolutionary history.

Pivotal temperature – the constant temperature that eggs are incubated at to produce 50 % male and 50% female offspring.

Polyphyly –  a group whose members come from multiple ancestral sources, regardless of similarity of characteristics



Rensch’s rule – size dimorphism increases with increasing body size when the male is the larger sex, and decreases with increasing average body size when the female is the larger sex.


Spongivorous – specializing in eating sponges (freshwater in case of the map turtles). This is primarily female microcephalic species.

Spring-fed river – a type of river fed by one or many spring heads or an aquifer. The water is usually relatively clear and water temperature does not fluctuate as much as other rivers due to the release of spring water at a constant temperature.

Sympatric – occurring within the same geographical area such as G. flavimaculata is sympatric with G. gibbonsi in the Pascagoula River.

Syntopic – occurring in the same microhabitat.


Turtle plinking – the despicable act of shooting turtles off of logs, rocks or any other basking platform for sport.