Glossary

In genetics, a recessive gene is a gene whose expression requires two identical copies to manifest. This means that an individual must inherit the recessive gene from each of their parents for the trait to appear.

For example, in reptiles, a recessive mutation like albino will only be visible if the animal has two copies of the albino gene. If it only has one, it will be a carrier but will not express the mutation. ("HET")

The translucent mutation in reptiles, notably bearded dragons (Pogona vitticeps), is characterized by lighter and slightly transparent skin, giving certain areas of the body an almost glassy appearance.

Translucent juveniles often have bluish bellies due to the transparency of their skin. Their eyes are usually darker, sometimes entirely black. This mutation is recessive and can be combined with other genetic traits to create unique morphs.

Melanism is a genetic mutation that causes an excessive production of melanin, the pigment responsible for dark colors. Unlike albinism or leucism, which reduce pigmentation, melanism makes the animal significantly darker, sometimes entirely black.

This trait can be hereditary or appear spontaneously. It is observed in certain reptile species, such as black snakes (e.g., melanism in some pythons or other ), which can provide an advantage in heat absorption or camouflage.

Albinism is a genetic mutation that prevents the production of melanin, the pigment responsible for dark colors in skin, scales, eyes, and hair. In reptiles, this results in individuals with light hues, often yellow, white, or pink, with red or translucent eyes.

A non-visual gene is a gene that does not directly affect the animal's appearance but can be passed on to offspring. In the case of recessive mutations, an individual may be a carrier without expressing the trait, but if mated with another carrier, the mutation may appear in the offspring.

A codominant gene is a gene whose two versions (alleles) are expressed simultaneously in a heterozygous individual. Unlike a dominant or recessive gene, neither allele masks the other.

For example, in reptile genetics, if an individual inherits two different co-dominant mutations, it may exhibit a mixture of the two traits or intermediate expression of the two genes.

In genetics, T+ (Tyrosinase positive) refers to a mutation that affects melanin production while retaining some ability to produce dark pigments. Unlike T- (Tyrosinase negative), where the animal produces no melanin, T+ animals can exhibit darker hues and better color retention.

This term is often used for T+ albino mutations, where the animal has reduced melanin but retains brown, orange, or yellowish hues.

T- (Tyrosinase negative) refers to a mutation in which the enzyme tyrosinase, necessary for the production of melanin, is completely absent or inactive. This results in a complete absence of dark pigments, giving the animal an albino appearance with light shades such as white, yellow, or pink.

Unlike T+ (Tyrosinase positive), where dark pigments may still be present, T- cells do not produce any melanin, making them completely devoid of black or brown.

Leucism is a genetic mutation that results in a partial or complete loss of pigment in the skin, scales, or feathers, while leaving the eyes normal in color. Unlike albinism, which only affects melanin production, leucism can affect multiple types of pigment, resulting in white, cream, or pale animals, sometimes with muted patterns.

A leucistic animal may be completely white or have remaining patches of color. This is a mutation often seen in certain reptiles, such as leucistic ball pythons, which have a uniform white color with black eyes.

Hypomelanism (or hypo) is a genetic mutation that reduces the amount of melanin, making the animal lighter than the wild form. Unlike albinism, which completely eliminates melanin, a hypo reptile retains dark pigments but in reduced amounts.

Hypomelanistic reptiles often have more vibrant colors, with more intense shades of yellow, orange, or red. This mutation can be recessive or codominant depending on the species. It is found in particular in ball pythons, bearded dragons, and some snakes.

Axanthism is a genetic mutation that prevents the production of yellow and red pigments (xanthophores), leaving only black, gray, and white colors visible.

An axanthic reptile will therefore have a duller and more monochrome appearance compared to the wild form. This mutation is often recessive and is observed in several species, such as ball pythons, snakes, or monitor lizards. Some individuals may regain yellowish hues as they age due to environmental factors or slight residual pigment production.

Leatherback is a genetic mutation found primarily in bearded dragons (Pogona vitticeps). It reduces the size and prominence of the dorsal scales, giving the skin a smoother, more supple texture, hence its name, which means "leatherback."

Leatherback bearded dragons often have brighter, more distinct colors because the lack of rough scales allows for better pigment visibility. This mutation can be co-dominant, producing silkbacks (complete lack of scales) when a leatherback is crossed with another leatherback.

A dominant gene is one that is visibly expressed whenever it is present, even if only one copy is present. This means that an individual carrying only one dominant version (heterozygous) will display the characteristic associated with that gene.

For example, in some reptiles, a specific color or pattern may be dominant, meaning that only one parent needs to pass on the gene for the offspring to express that trait. Unlike recessive genes, which require two copies to be visible, dominant genes appear as soon as they are inherited from a parent.

Thermoregulation is the process by which an animal adjusts its body temperature to remain within an optimal range. In reptiles, which are ectothermic, this means they rely on external heat sources to regulate their temperature.

They use several behaviors to achieve this:

• Basking (exposure to sunlight or a heat lamp) to increase their temperature.

• Take refuge in the shade or in a shelter to avoid overheating.

• Change position or substrate to adjust their thermal absorption.

In captivity, good thermoregulation is essential. A terrarium must provide a thermal gradient, with a warm zone and a cooler zone, to allow the animal to choose the temperature it needs.

Viviparous animals are animals that give birth to fully formed young without going through an external egg phase. Unlike oviparous animals, which lay eggs, viviparous animals develop their embryos inside the mother's body until birth.

Among reptiles, some species, such as boas and some skinks, are viviparous. This strategy allows the young to be better protected during their development, especially in environments where laying eggs would be risky.

Ovoviviparous animals are those whose embryos develop inside eggs within the mother’s body, but without a direct nutritional connection to her. Once mature, the young hatch inside and are born live.

Among reptiles, several species, such as some snakes (boa constrictor, vipers) and lizards, are ovoviviparous. This reproductive mode helps better protect the eggs from predators and harsh environmental conditions.

The gonopodium is a modified reproductive organ found in male viviparous fish, such as guppies, mollies, platys, and swordtails. It is a transformation of the anal fin into an elongated tube that allows internal insemination of females.

This organ is a good way to distinguish males from females, the latter having a larger, fan-shaped anal fin. The gonopod is essential for reproduction in viviparous species, as it allows sperm to be directly transmitted to the female.

Brackish water is water whose salinity is intermediate between fresh water and sea water. It contains a low concentration of salt, generally between 0.5 and 30 grams per liter.

It is found naturally in estuaries, mangroves, and some lagoons. Many fish, such as archerfish, figure-8 pufferfish, and scat, live in brackish water and require gradual salinity adjustment in captivity for their well-being.

pH and salinity are crucial parameters to monitor in an aquarium, as they influence the health and behavior of fish and other aquatic organisms.

Definition: pH measures the acidity or alkalinity of water on a scale from 0 to 14, with 7 being neutral.

Importance: Most fish and plant species have an optimal pH range in which they thrive. For example, tropical fish generally prefer a pH between 6.5 and 7.5.

Adjustment: pH can be adjusted using specific chemicals, substrates, or by adding plants.

Definition: Salinity measures the concentration of dissolved salts in the water, usually expressed in parts per thousand (‰).

Importance: Freshwater, brackish, and saltwater fish have different salinity needs. For example, marine fish require a salinity of about 35‰, while freshwater fish thrive in salinity close to 0‰.

Measurement: Salinity can be measured using a refractometer or a hydrometer.

Maintaining appropriate pH and salinity levels is essential to ensure a healthy and balanced environment for aquarium inhabitants.

Constriction is a hunting method used by some snakes to capture and immobilize their prey. The snake grabs its prey with its mouth, coils around it, and gradually squeezes to restrict its movement and inhibit its breathing. Once immobilized, the snake ingests the prey whole. This technique is common among species such as pythons and boas, allowing them to efficiently feed on rodents and other small animals.

Amplexus is a reproductive behavior observed in some amphibian species, particularly frogs and toads. During amplexus, the male clings to the female by wrapping himself around her, usually holding onto her back. This process allows the male to fertilize the eggs as the female deposits them in the water or on a surface.

Amplexus can last for several hours or even days and is essential for ensuring egg fertilization and reproductive success. This behavior can vary depending on species and environmental conditions.

Colubrids are a diverse family of snakes, comprising mostly non-venomous species. They have slender bodies, distinct heads, and are found in a variety of habitats, from forests to deserts. Their diet varies, including rodents, birds, and insects. While most are non-venomous, some species have mild venom. Popular examples in terrarium keeping include the rat snake and the king snake.

The cloaca is an anatomical cavity found in many animals, including reptiles, birds, and amphibians. It serves as an exit point for the urinary, reproductive, and digestive systems, allowing the evacuation of feces, urine, and reproductive products. The cloaca plays a crucial role in reproduction, particularly in reptiles and birds, where it allows for egg laying and sperm transfer. It is an adaptive feature that consolidates several bodily functions from a single opening.

Dimorphism refers to the difference in shape, size, or appearance between two sexes of the same species. This phenomenon is common in the animal kingdom and can manifest itself in different ways:

1. Size differences: In some species, one sex is significantly larger or smaller than the other. For example, in birds of prey, females are often larger than males.

2. Color Differences: Sexual dimorphism can result in color variations between the sexes, as in many birds where males display bright colors to attract females, while females have more muted hues for camouflage.

3. Morphological differences: Some species have specific physical differences, such as distinct ornaments, structures, or behavioral characteristics. For example, male deer have antlers, while females do not.

Sexual dimorphism plays an important role in reproduction and mating behaviors, influencing natural selection and the evolution of species.

Adaptation is the process by which organisms modify their physical, behavioral, or physiological characteristics to better survive and reproduce in their environment. Here are some key points about adaptation:

1. Types of adaptations:

   • Morphological: Changes in physical structure, such as shape, size, or color. For example, chameleons have the ability to change color for camouflage.

   • Physiological: Internal changes that affect metabolism, such as the ability of some reptiles to conserve water in arid environments.

   • Behavioral: Changes in the behavior of organisms, such as birds migrating to avoid extreme weather conditions.

2. Adaptation mechanisms: Adaptation typically occurs over long periods of time through evolution and natural selection. Individuals with favorable traits are more likely to survive and reproduce, passing these traits on to the next generation.

3. Importance of adaptation: Adaptations allow species to adjust to changes in their environment, such as climate variations, resource availability, and interactions with other species. This contributes to biodiversity and ecosystem resilience.

In summary, adaptation is an essential process that helps organisms survive and thrive in diverse and changing environments.

The term "crepuscular" refers to animals that are active primarily at dawn and dusk, the times when light is low, between day and night. This activity allows them to avoid the high temperatures of the day and reduce the risk of predation. Crepuscular animals include certain species of mammals, birds, reptiles, and insects. These animals often have specific adaptations, such as enhanced night vision, to help them navigate and hunt in low-light conditions.

Parthenogenesis is a method of asexual reproduction in which an egg develops into an individual without fertilization by a sperm. This process is found in some animal species, such as some reptiles, insects, and fish, as well as in some plants.

In parthenogenesis, the egg divides and develops into a new organism, usually identical to the mother, meaning there is no genetic diversity due to interbreeding. This method of reproduction can be advantageous in environments where sexual partners are rare or where conditions favor rapid reproduction. However, it can also limit genetic variability, making populations more vulnerable to disease and environmental change.

The osteoderm is a bony structure derived from the skin, found in some reptiles and amphibians. These bony plates or scales are usually located beneath the epidermis and may contribute to body protection, temperature regulation, and camouflage.

Osteoderms are found in various groups of reptiles, such as crocodiles, turtles, and some lizards, and can vary in shape, size, and arrangement. They play an important role in defense against predators and adaptation to the environment, providing natural armor and participating in thermoregulation.

The Jacobson's organ, also known as the vomeronasal organ, is a specialized sensory organ found in some reptiles, amphibians, mammals, and some fish. It is located in the oral cavity, near the roof of the mouth, and is used to detect chemical molecules in the environment, playing a key role in the sense of smell.

In reptiles, such as snakes, the Jacobson's organ is particularly important for detecting pheromones and other chemical signals, helping to locate prey, recognize potential mates, or avoid predators. These animals often use their tongues to capture odorous particles from the air or ground, which are then transferred to this organ for further analysis.

Invertebrates are animals that do not have a backbone. This group includes a wide variety of species, such as insects, spiders, crustaceans, mollusks, worms, and cnidarians (like jellyfish and corals). Invertebrates make up about 95% of animal species on Earth and are found in almost every habitat, from oceans to land. They play essential ecological roles, including as pollinators, decomposers, and prey for other animals. Their morphological and functional diversity is immense, allowing them to adapt to a variety of environments and ecosystems.

Heat-sensitive pits are specialized structures found in certain reptiles, such as snakes of the Viperidae family (vipers) and rattlesnakes. They are located on the face, between the eyes and nostrils, and allow the animal to detect changes in heat in its environment. These pits act as infrared sensors, allowing reptiles to perceive heat sources, such as warm-blooded prey, even in the dark. This gives them an advantage when hunting by allowing them to locate and target their prey effectively.

The term "diurnal" refers to animals that are active during the day. These animals spend most of their time foraging, reproducing, and interacting with their environment during the day. Diurnal species, such as some birds, reptiles, mammals, and insects, often have adaptations that allow them to see well and move around in sunlight. Their daytime activity also helps them avoid some nocturnal predators.

Amphibians are vertebrates that include frogs, toads, salamanders, and axolotls. They are characterized by moist, permeable skin and a two-phase life cycle: aquatic (as tadpoles) and terrestrial (as adults). Adapted to diverse habitats, they play an important ecological role by controlling insect populations and serving as prey. However, they are threatened by habitat loss, pollution, and disease, necessitating conservation efforts to protect them.

A terrarium is a confined space designed to recreate a natural environment and house reptiles, amphibians, invertebrates, or plants. There are several types of terrariums adapted to the specific needs of the species they accommodate:

• Desert terrarium: dry environment with sandy substrate, rocks, and hiding spots.

• Tropical terrarium: warm and humid environment with plants, moss, and wood.

• Arboreal terrarium: vertical setup suited for climbing species with branches and foliage.

• Terrestrial terrarium: wider than tall, for ground-dwelling species.

• Paludarium: a mix between terrarium and aquarium, combining terrestrial and aquatic zones.

• Bioactive terrarium: self-sustaining ecosystem integrating live plants, microorganisms, and detritivores for reduced maintenance.

A paludarium is a type of terrarium that combines terrestrial and aquatic elements to recreate a semi-aquatic ecosystem. It is inspired by wetlands such as swamps, tropical rivers, and mangroves.

• Terrestrial zone: Composed of substrate, tropical or epiphytic plants, and sometimes branches or rocks for climbing species.

• Aquatic zone: Includes a body of water with filtration and possibly aquatic fauna such as fish, shrimp or amphibians.

• Emerged zone: Interface between water and land, where certain plants and animals adapt to both environments.

A bioactive terrarium is a habitat that mimics a natural and balanced ecosystem, providing a healthy and enriching environment for reptiles. It integrates live plants, a suitable substrate, and a community of decomposer organisms such as isopods and earthworms that help recycle waste and maintain cleanliness. Plants provide oxygen, humidity, and hiding spots, while the substrate supports natural cycles like humidity regulation.

This type of terrarium not only improves animal well-being but also reduces maintenance since the system largely self-regulates. It is an ecological and aesthetic approach that values nature in all its complexity.

Brumation is a dormancy period experienced by many reptiles, especially those originating from temperate or desert climates. Often compared to mammalian hibernation, it usually occurs when temperatures drop and daylight decreases, simulating winter conditions. During this time, reptiles slow their metabolism, eat little or not at all, and often remain hidden or immobile.

Brumation is a natural process that allows reptiles to conserve energy in preparation for the return of warmer temperatures. For breeders, it is crucial to properly prepare a reptile for brumation by ensuring it is healthy and well-hydrated, and to provide a safe and stable environment for this resting period.​

Ecothermy is a characteristic of reptiles and many other ectothermic animals, which do not produce internal heat to regulate their body temperature. Unlike mammals and birds, ectotherms rely primarily on their environment to regulate their temperature. For example, a reptile may bask in the sun to warm up or seek shade to cool down. This process allows them to conserve energy, as they do not need to burn calories to generate body heat. However, it makes them vulnerable to extreme environmental conditions. Ecothermy is a fascinating mechanism that reflects the adaptation of reptiles to their natural environment.

Epiphytic plants are fascinating! They grow on other plants, such as trees, without being parasitic. Instead of drawing nutrients from their host, they absorb water and minerals directly from the air, rain, or debris that accumulates around them. This unique adaptation allows them to colonize areas where soil resources are limited, such as tropical rainforests.

Chitin is a natural substance found in the exoskeleton of many invertebrates, such as insects, arachnids, and crustaceans. It is composed of chains of polysaccharides, which give it a strong and resistant structure. It plays an essential role by providing protection and supporting the animals’ internal organs.

In biology and aquaristics, spectrum refers to the full range of visible and invisible light wavelengths, often used for lighting. Full-spectrum lighting fixtures, popular in aquariums and terrariums, mimic natural daylight, encompassing the wavelengths necessary for plant growth and animal well-being.

A full spectrum includes UV (ultraviolet) rays, essential for some reptiles that synthesize vitamin D, as well as red and blue wavelengths that promote photosynthesis in aquatic or terrestrial plants. These types of lighting also play a role in enhancing the colors of fish and plants, creating an aesthetically pleasing and functional environment.

The circadian cycle is an essential biological process that regulates the daily rhythms of many living things, including humans, animals, and even some plants. This cycle is based on a period of approximately 24 hours and is influenced by external factors such as light and darkness. It affects a variety of functions, such as sleep, activity, body temperature, and hormone production.

In reptiles and other captive animals, managing the circadian rhythm is crucial to their well-being. Recreating appropriate periods of light and darkness can support their natural behaviors, such as hunting, resting, or breeding. In aquariums and terrariums, using artificial light cycles helps synchronize their internal clock with their environment.

The notation 1.0, 0.1, or 0.0.1 is a system commonly used in animal breeding to indicate the sex and number of individuals. This method, both simple and accurate, allows for the rapid description of the composition of a group of animals, particularly in reptiles, amphibians, and other exotic species.

The system is based on three numbers separated by periods. The first number corresponds to the number of males, the second to the number of females, and the third to the number of individuals of unknown or undetermined sex. For example, 1.0 indicates a male, 0.1 a female, and 0.0.1 a specimen whose sex has not yet been identified.

Shedding is a natural process by which many animals, including reptiles, amphibians, and insects, get rid of their old skin or exoskeleton to make way for a new one. This renewal is essential for their growth, health, and, for some insects, their complete transformation.

In reptiles, shedding often accompanies growth and appears as skin peeling off in patches or in one piece. Amphibians shed more frequently, often discreetly, and consume their old skin to recycle nutrients. Insects go through well-defined stages and must shed at each step of their development.

In reptiles, amphibians, and insects, lethargic behavior refers to an animal that is abnormally inactive, slow, or unresponsive to its environment. This decrease in activity can have several causes: inadequate temperature, poor diet, imminent shedding, significant stress, or an underlying health issue.

A lethargic animal spends more time hiding, moves little, and reacts weakly to stimuli. It is important to quickly identify the cause, as lethargy can be a sign of environmental imbalance or a condition requiring special attention. Careful monitoring of terrarium parameters, diet, and usual behavior helps prevent such situations.

In a terrarium, creating distinct zones called hot spots and cold spots is essential for the well-being of reptiles and amphibians. The hot spot is a heated area that allows the animal to increase its body temperature through a heat source, while the cold spot provides a cooler space where it can regulate itself.

This thermal variation mimics their natural habitat and allows them to adopt efficient thermoregulation, moving between heat and coolness as needed. Without these zones, the animal can suffer from stress, digestive problems, or a slowed metabolism.

For a balanced terrarium, it is important to regularly measure the temperature in different places and adjust the lighting and heating accordingly.

UVA and UVB rays are types of ultraviolet light essential for the health of reptiles and some amphibians.

UVA influences behavior, reproduction, appetite, and the overall well-being of the animal. It helps stimulate natural activity.

UVB is crucial for the synthesis of vitamin D3, which enables calcium absorption necessary for strong bones and a healthy metabolism. Without UVB, reptiles can develop serious deficiencies such as metabolic bone disease.

In a terrarium, it is important to use lamps specifically designed to replicate these rays, respecting recommended exposure times and distances.

In the world of animal breeding and trading, it is important to know the origin of specimens, as this influences their behavior, health, and adaptation to captivity. The terms CB, CBB, LTC, and WC help to better understand this origin.

A CB (Captive Bred) animal is one born and raised entirely in captivity. This type of animal is generally better adapted to life in a terrarium, less stressed, and healthier than those from the wild. The term CBB (Captive Born and Bred) goes further, indicating that the animal comes from several generations of captive breeding, which guarantees genetic stability and good long-term acclimatization.

An animal classified as LTC (Long Term Captive) refers to a specimen that has been kept in captivity for a long period of time, often several years. It may come from breeding or have been captured in the wild, but its time in captivity gives it a better adaptation.

Finally, WC (Wild Caught) animals are taken directly from the wild. These specimens are more susceptible to stress and disease and require special attention to adapt well to life in captivity.

In most male reptiles, reproduction involves an anatomical feature called the hemipenis. These are two internal reproductive organs located at the base of the tail. During mating, only one of the two hemipenes is used at a time. This structure is unique to many lizards and snakes and can sometimes be observed briefly during sexing or reproductive behavior.

Females, on the other hand, do not have this characteristic, which makes it a useful clue for determining sex in some species. The presence or eversion of the hemipenes is always done with caution, by an experienced person, to avoid injury or stress to the animal.

Femoral pores are small openings located on the inner side of the thighs, present in many species of lizards, such as geckos and iguanas. They play a role in chemical communication, as they release odorous substances used to mark territory or attract a mate.

In some species, males have more visible, more numerous, or more pronounced femoral pores than females, making them a useful clue for sexing. Their appearance can vary depending on the animal's age, season, or hormonal activity.

Pelvic spurs are small growths located on either side of the cloaca in some snake species, such as boas and pythons. These structures, remnants of ancestral hind limbs, are more developed in males and are often used during reproduction to stimulate the female.

Anthropomorphism is the act of attributing human emotions, intentions, or behaviors to animals. In the world of reptiles, amphibians, invertebrates, and fish, this tendency can lead to misinterpretations. For example, thinking that a gecko is "sulking" or that a snake is "angry" can misjudge its true state.

These species communicate in ways that are very different from those of mammals. To properly care for them, it's important to observe their natural signals (position, colors, activity patterns) without assuming human intentions. Understanding their biology, rather than interpreting it with our human eyes, is essential to their well-being.