Chameleons or chamaeleons (
family
Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...
Chamaeleonidae) are a distinctive and highly specialized
clade
A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...
of
Old World
The "Old World" is a term for Afro-Eurasia that originated in Europe , after Europeans became aware of the existence of the Americas. It is used to contrast the continents of Africa, Europe, and Asia, which were previously thought of by the ...
lizard
Lizards are a widespread group of squamate reptiles, with over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic since it excludes the snakes and Amphisbaenia alt ...
s with 202 species described as of June 2015.
The members of this family are best known for their distinct range of colors, being capable of shifting to different hues and degrees of brightness. The large number of species in the family exhibit considerable variability in their capacity to change color. For some, it is more of a shift of brightness (shades of brown); for others, a plethora of color-combinations (reds, yellows, greens, blues) can be seen.
Chameleons are distinguished by their
zygodactyl
In biology, dactyly is the arrangement of digits (fingers and toes) on the hands, feet, or sometimes wings of a tetrapod animal. It comes from the Greek word δακτυλος (''dáktylos'') = "finger".
Sometimes the ending "-dactylia" is use ...
ous feet, their
prehensile
Prehensility is the quality of an appendage or organ (anatomy), organ that has Adaptation (biology), adapted for grasping or holding. The word is derived from the Latin term ''prehendere'', meaning "to grasp". The ability to grasp is likely der ...
tail, their laterally compressed bodies, their head casques, their projectile tongues, their swaying gait, and crests or horns on their brow and snout. Chameleons' eyes are independently mobile, and because of this there are two separate, individual images that the brain is analyzing of the chameleon’s environment. When hunting prey, they focus forward in coordination, affording the animal
stereoscopic vision
Stereopsis () is the component of depth perception retrieved through binocular vision.
Stereopsis is not the only contributor to depth perception, but it is a major one. Binocular vision happens because each eye receives a different image becaus ...
.
Chameleons are adapted for climbing and visual hunting. The use of their prehensile tail offers stability when they are moving or resting while on a branch in the canopy; because of this, their tail is often referred to as a "fifth limb." Another character that is advantageous for being arboreal is how laterally compressed their bodies are; it is important for them to distribute their weight as evenly as possible as it confers stability on twigs and branches in the trees. They live in warm habitats that range from
rainforest
Rainforests are characterized by a closed and continuous tree canopy, moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforest can be classified as tropical rainforest or temperate rainfores ...
to
desert
A desert is a barren area of landscape where little precipitation occurs and, consequently, living conditions are hostile for plant and animal life. The lack of vegetation exposes the unprotected surface of the ground to denudation. About on ...
conditions, with various species occurring in Africa,
Madagascar
Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa ...
, southern Europe, and across southern Asia as far as
Sri Lanka
Sri Lanka (, ; si, ශ්රී ලංකා, Śrī Laṅkā, translit-std=ISO (); ta, இலங்கை, Ilaṅkai, translit-std=ISO ()), formerly known as Ceylon and officially the Democratic Socialist Republic of Sri Lanka, is an ...
. They have been
introduced to
Hawaii
Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only stat ...
,
California
California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...
, and
Florida
Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and to ...
.
Etymology
![Ustad Mansur Chameleon](https://upload.wikimedia.org/wikipedia/commons/a/a3/Ustad_Mansur_Chameleon.jpg)
The English word ''chameleon'' ( ) is a simplified spelling of
Latin
Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...
', a borrowing of the
Greek
Greek may refer to:
Greece
Anything of, from, or related to Greece, a country in Southern Europe:
*Greeks, an ethnic group.
*Greek language, a branch of the Indo-European language family.
**Proto-Greek language, the assumed last common ancestor ...
' (''khamailéōn''), a
compound
Compound may refer to:
Architecture and built environments
* Compound (enclosure), a cluster of buildings having a shared purpose, usually inside a fence or wall
** Compound (fortification), a version of the above fortified with defensive struc ...
of ' (''khamaí'') "on the ground" and ' (''léōn'') "lion".
Classification
In 1986, the family Chamaeleonidae was divided into two subfamilies,
Brookesiinae
The Family Chamaeleonidae was divided into two subfamilies, Brookesiinae and Chamaeleoninae, by Klaver and Böhme in 1986. Under this classification, Brookesiinae included the genera ''Brookesia'' and ''Rhampholeon'', as well as the genera later ...
and
Chamaeleoninae
Chamaeleoninae is the nominotypical subfamily of chameleons (family Chamaeleonidae). The Family Chamaeleonidae was divided into two subfamilies, Brookesiinae and Chamaeleoninae, by Klaver and Böhme in 1986. Since its erection in 1986, however, ...
.
Under this classification,
Brookesiinae
The Family Chamaeleonidae was divided into two subfamilies, Brookesiinae and Chamaeleoninae, by Klaver and Böhme in 1986. Under this classification, Brookesiinae included the genera ''Brookesia'' and ''Rhampholeon'', as well as the genera later ...
included the genera ''
Brookesia
''Brookesia'' is a genus of chameleons, endemic to Madagascar, that range from small to very small in size, and are known collectively as leaf chameleons (though this name also commonly is used for species in the genera ''Rieppeleon'' and ''Rham ...
'' and ''
Rhampholeon
''Rhampholeon'' is a genus of small chameleons, commonly known as pygmy chameleons or African leaf chameleons, found in central East Africa (extending slightly into adjacent DR Congo). They are found in forests, woodlands, thickets, and savanna, ...
'', as well as the genera later split off from them (''
Palleon
''Palleon'' is a genus of small chameleons erected in 2013 for a small clade formerly assigned to the genus ''Brookesia''. The species of ''Palleon ''are endemic to Madagascar
Madagascar (; mg, Madagasikara, ), officially the Republic ...
'' and ''
Rieppeleon
''Rieppeleon'' is a genus of small, typically brown chameleons found in forests and savannas in central East Africa (extending slightly into adjacent DR Congo). They are found at low levels in bushes, or on the ground among grass or leaf litter.
...
''), while
Chamaeleoninae
Chamaeleoninae is the nominotypical subfamily of chameleons (family Chamaeleonidae). The Family Chamaeleonidae was divided into two subfamilies, Brookesiinae and Chamaeleoninae, by Klaver and Böhme in 1986. Since its erection in 1986, however, ...
included the genera ''
Bradypodion
''Bradypodion'' (meaning "slow-footed" in Greek) is one of six genera of chameleons within the "true" or "typical" chameleons ( Family Chamaeleonidae). They are native to southern Africa, and are sometimes collectively called South African dw ...
'', ''
Calumma
''Calumma'' is a genus of chameleons endemic and restricted to Madagascar. The species formerly named ''Calumma tigris'' was transferred to the genus '' Archaius'' by Townsend et al., when they found that it is more closely related to ''Rieppe ...
'', ''
Chamaeleo
''Chamaeleo'' is a genus of chameleons in the family Chamaeleonidae. Most species of the genus ''Chamaeleo'' are found in sub-Saharan Africa, but a few species are also present in northern Africa, southern Europe, and southern Asia east to Indi ...
'', ''
Furcifer
''Furcifer'' is a genus of chameleons whose member species are mostly endemic to Madagascar, but ''F. cephalolepis'' and ''F. polleni'' are endemic to the Comoros. Additionally, ''F. pardalis'' has been introduced to Réunion and Mauritius, whil ...
'' and ''
Trioceros
''Trioceros'' is a genus of lizards in the family Chamaeleonidae. ''Trioceros'' was considered a subgenus of the genus ''Chamaeleo'' until 2009, when it was elevated to full genus level.
Species and subspecies
The following species and subspecie ...
'', as well as the genera later split off from them (''
Archaius'', ''
Nadzikambia
Currently, two species are placed in the recently established genus ''Nadzikambia'' (derived from the species' name in Chichewa). They are plesiomorphic, small chameleons from the Ruo Gorge forest on Mount Mulanje in Malawi and Mount Mabu in Mo ...
'' and ''
Kinyongia
''Kinyongia'' (derived from the group's name in Kiswahili language) is a chameleon genus recently established for several plesiomorphic species found in forest and woodland in Kenya, Tanzania, Uganda, Rwanda, and far eastern DR Congo. All excep ...
''). Since that time, however, the validity of this subfamily designation has been the subject of much debate,
although most phylogenetic studies support the notion that the pygmy chameleons of the subfamily Brookesiinae are not a
monophyletic
In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gro ...
group.
While some authorities have previously preferred to use this subfamilial classification on the basis of the absence of evidence principle,
these authorities later abandoned this subfamilial division, no longer recognizing any subfamilies with the family Chamaeleonidae.
In 2015, however, Glaw reworked the subfamilial division by placing only the genera ''
Brookesia
''Brookesia'' is a genus of chameleons, endemic to Madagascar, that range from small to very small in size, and are known collectively as leaf chameleons (though this name also commonly is used for species in the genera ''Rieppeleon'' and ''Rham ...
'' and ''
Palleon
''Palleon'' is a genus of small chameleons erected in 2013 for a small clade formerly assigned to the genus ''Brookesia''. The species of ''Palleon ''are endemic to Madagascar
Madagascar (; mg, Madagasikara, ), officially the Republic ...
'' within the
Brookesiinae
The Family Chamaeleonidae was divided into two subfamilies, Brookesiinae and Chamaeleoninae, by Klaver and Böhme in 1986. Under this classification, Brookesiinae included the genera ''Brookesia'' and ''Rhampholeon'', as well as the genera later ...
subfamily, with all other genera being placed in
Chamaeleoninae
Chamaeleoninae is the nominotypical subfamily of chameleons (family Chamaeleonidae). The Family Chamaeleonidae was divided into two subfamilies, Brookesiinae and Chamaeleoninae, by Klaver and Böhme in 1986. Since its erection in 1986, however, ...
.
Change of color
Some chameleon species are able to change their
skin coloration. Different chameleon species are able to vary their coloration and
pattern
A pattern is a regularity in the world, in human-made design, or in abstract ideas. As such, the elements of a pattern repeat in a predictable manner. A geometric pattern is a kind of pattern formed of geometric shapes and typically repeated l ...
through combinations of pink, blue, red, orange, green, black, brown, light blue, yellow, turquoise, and purple.
Chameleon skin has a superficial layer which contains pigments, and under the layer are cells with very small (nanoscale)
guanine
Guanine () ( symbol G or Gua) is one of the four main nucleobases found in the nucleic acids DNA and RNA, the others being adenine, cytosine, and thymine (uracil in RNA). In DNA, guanine is paired with cytosine. The guanine nucleoside is called ...
crystals. Chameleons change color by "actively tuning the photonic response of a lattice of small guanine nanocrystals in the s-iridophores".
This tuning, by an unknown molecular mechanism, changes the wavelength of light reflected off the crystals which changes the color of the skin. The color change was duplicated ''
ex vivo
''Ex vivo'' (Latin: "out of the living") literally means that which takes place outside an organism. In science, ''ex vivo'' refers to experimentation or measurements done in or on tissue from an organism in an external environment with minimal ...
'' by modifying the
osmolarity
Osmotic concentration, formerly known as osmolarity, is the measure of solute concentration, defined as the number of osmoles (Osm) of solute per litre (L) of solution (osmol/L or Osm/L). The osmolarity of a solution is usually expressed as Osm/L ...
of pieces of white skin.
![Colour change and iridophore types in panther chameleons](https://upload.wikimedia.org/wikipedia/commons/4/43/Colour_change_and_iridophore_types_in_panther_chameleons.png)
Color change in chameleons has functions in
camouflage
Camouflage is the use of any combination of materials, coloration, or illumination for concealment, either by making animals or objects hard to see, or by disguising them as something else. Examples include the leopard's spotted coat, the ...
, but most commonly in social signaling and in reactions to temperature and other conditions. The relative importance of these functions varies with the circumstances, as well as the species. Color change signals a chameleon's physiological condition and intentions to other chameleons. Because chameleons are
ectotherm
An ectotherm (from the Greek () "outside" and () "heat") is an organism in which internal physiological sources of heat are of relatively small or of quite negligible importance in controlling body temperature.Davenport, John. Animal Life ...
ic, another reason why they change color is to regulate their body temperatures, either to a darker color to absorb light and heat to raise their temperature, or to a lighter color to reflect light and heat, thereby either stabilizing or lowering their body temperature.
Chameleons tend to show brighter colors when displaying aggression to other chameleons, and darker colors when they submit or "give up". Some species, particularly those of
Madagascar
Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa ...
and some African genera in rainforest habitats, have blue
fluorescence
Fluorescence is the emission of light by a substance that has absorbed light or other electromagnetic radiation. It is a form of luminescence. In most cases, the emitted light has a longer wavelength, and therefore a lower photon energy, tha ...
in their skull
tubercle
In anatomy, a tubercle (literally 'small tuber', Latin for 'lump') is any round nodule, small eminence, or warty outgrowth found on external or internal organs of a plant or an animal.
In plants
A tubercle is generally a wart-like projection ...
s, deriving from bones and possibly serving a signaling role.
Some species, such as
Smith's dwarf chameleon
Smith's dwarf chameleon or the Elandsberg dwarf chameleon (''Bradypodion taeniabronchum'') is a species of lizard in the family Chamaeleonidae endemic to South Africa
South Africa, officially the Republic of South Africa (RSA), is the ...
, adjust their colors for camouflage by the vision of the specific predator species (bird or snake) by which they are being threatened.
Chameleons have two superimposed layers within their skin that control their color and thermoregulation. The top layer contains a lattice of guanine nanocrystals, and by exciting this lattice the spacing between the nanocrystals can be manipulated, which in turn affects which wavelengths of light are reflected and which are absorbed. Exciting the lattice increases the distance between the nanocrystals, and the skin reflects longer wavelengths of light. Thus, in a relaxed state the crystals reflect blue and green, but in an excited state the longer wavelengths such as yellow, orange, green, and red are reflected.
The skin of a chameleon also contains some yellow pigments, which combined with the blue reflected by a relaxed crystal lattice results in the characteristic green color which is common of many chameleons in their relaxed state. Chameleon color palettes have evolved through evolution and the environment. Chameleons living in the forest have a more defined and colorful palette compared to those living in the desert or savanna, which have more of a basic, brown, and charred palette.
Evolution
The oldest described chameleon is ''
Anqingosaurus brevicephalus'' from the Middle Paleocene (about 58.7–61.7
mya) of China.
Other chameleon fossils include ''
Chamaeleo caroliquarti
''Chamaeleo caroliquarti'' is an extinct species of chameleon from Lower Miocene-aged strata of the Czech Republic
The Czech Republic, or simply Czechia, is a landlocked country in Central Europe. Historically known as Bohemia, it ...
'' from the Lower Miocene (about 13–23 mya) of the Czech Republic and Germany, and ''Chamaeleo intermediate'' from the Upper Miocene (about 5–13 mya) of Kenya.
The chameleons are probably far older than that, perhaps sharing a common ancestor with
iguanids and
agamids
Agamidae is a family of over 300 species of iguanian lizards indigenous to Africa, Asia, Australia, and a few in Southern Europe. Many species are commonly called dragons or dragon lizards.
Overview
Phylogenetically, they may be sister to th ...
more than 100 mya (agamids being more closely related). Since fossils have been found in Africa, Europe, and Asia, chameleons were certainly once more widespread than they are today.
Although nearly half of all chameleon species today live in Madagascar, this offers no basis for speculation that chameleons might originate from there. In fact, it has recently been shown that chameleons most likely originated in mainland Africa.
It appears there were two distinct oceanic migrations from the mainland to Madagascar. The diverse speciation of chameleons has been theorized to have directly reflected the increase in open habitats (savannah, grassland, and heathland) that accompanied the Oligocene period.
Monophyly
In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic grou ...
of the family is supported by several studies.
Daza ''et al.'' (2016) described a small (10.6 mm in snout-vent length), probably
neonatal
An infant or baby is the very young offspring of human beings. ''Infant'' (from the Latin word ''infans'', meaning 'unable to speak' or 'speechless') is a formal or specialised synonym for the common term ''baby''. The terms may also be used to ...
lizard preserved in the Cretaceous (
Albian
The Albian is both an age of the geologic timescale and a stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early/Lower Cretaceous Epoch/Series. Its approximate time range is 113.0 ± 1.0 Ma to 100.5 ± 0.9 M ...
-
Cenomanian
The Cenomanian is, in the ICS' geological timescale, the oldest or earliest age of the Late Cretaceous Epoch or the lowest stage of the Upper Cretaceous Series. An age is a unit of geochronology; it is a unit of time; the stage is a unit in the s ...
boundary) amber from
Myanmar
Myanmar, ; UK pronunciations: US pronunciations incl. . Note: Wikipedia's IPA conventions require indicating /r/ even in British English although only some British English speakers pronounce r at the end of syllables. As John C. Wells, Joh ...
. The authors noted that the lizard has "short and wide skull, large orbits, elongated and robust lingual process, frontal with parallel margins, incipient prefrontal boss, reduced vomers, absent retroarticular process, low presacral vertebral count (between 15 and 17) and extremely short, curled tail"; the authors considered these traits to be indicative of the lizard's affiliation with Chamaeleonidae. The phylogenetic analysis conducted by the authors indicated that the lizard was a
stem-chamaeleonid. However, Matsumoto &
Evans
Evans may refer to:
People
*Evans (surname)
*List of people with surname Evans
Places United States
*Evans Island, an island of Alaska
*Evans, Colorado
*Evans, Georgia
*Evans County, Georgia
*Evans, New York
*Evans Mills, New York
*Evans City, ...
(2018) reinterpreted this specimen as an
albanerpetontid
The Albanerpetontidae are an extinct family of small amphibians, native to the Northern Hemisphere during the Mesozoic and Cenozoic. The only members of the order Allocaudata, they are thought to be allied with living amphibians belonging to Lissa ...
amphibian. This specimen was given the name ''
Yaksha perettii
''Yaksha perettii'' is an extinct species of albanerpetontid amphibian, and the only species in the genus ''Yaksha''. It is known from three specimens found in Cenomanian aged Burmese amber from Myanmar. The remains of ''Yaksha perettii'' are the ...
'' in 2020, and was noted to have several convergently chameleon-like features, including adaptations for ballistic feeding.
While the exact evolutionary history of color change in chameleons is still unknown, there is one aspect of the evolutionary history of chameleon color change that has already been conclusively studied: the effects of signal efficacy. Signal efficacy, or how well the signal can be seen against its background, has been shown to correlate directly to the spectral qualities of chameleon displays.
Dwarf chameleons, the chameleon of study, occupy a wide variety of habitats from forests to grasslands to shrubbery. It was demonstrated that chameleons in brighter areas tended to present brighter signals, but chameleons in darker areas tended to present relatively more contrasting signals to their backgrounds. This finding suggests that signal efficacy (and thus habitat) has affected the evolution of chameleon signaling. Stuart-Fox et al. note that it makes sense that selection for crypsis is not seen to be as important as selection for signal efficacy, because the signals are only shown briefly; chameleons are almost always muted cryptic colors.
Description
![Chameleon in Berenty Madagascar 0001](https://upload.wikimedia.org/wikipedia/commons/c/c4/Chameleon_in_Berenty_Madagascar_0001.JPG)
Chameleons vary greatly in size and body structure, with maximum total lengths varying from in male ''
Brookesia micra
''Brookesia micra'', also known as the Nosy Hara leaf chameleon is a species of chameleons from the islet of Nosy Hara in Antsiranana, Madagascar. At the time of its discovery, it was the smallest known chameleon and among the smallest reptiles ...
'' (one of the world's
smallest reptiles) to in the male ''
Furcifer oustaleti''.
Many have head or facial ornamentation, such as nasal protrusions, or horn-like projections in the case of
''Trioceros jacksonii'', or large crests on top of their heads, like ''
Chamaeleo calyptratus
''Chamaeleo'' is a genus of chameleons in the family Chamaeleonidae. Most species of the genus ''Chamaeleo'' are found in sub-Saharan Africa, but a few species are also present in northern Africa, southern Europe, and southern Asia east to Indi ...
''. Many species are
sexually dimorphic
Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most ani ...
, and males are typically much more ornamented than the female chameleons.
Typical sizes of species of chameleon commonly kept in captivity or as pets are:
The feet of chameleons are highly adapted to
arboreal locomotion
Arboreal locomotion is the locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally, but others are exclusively arboreal. The habitats pose num ...
, and species such as ''Chamaeleo namaquensis'' that have secondarily adopted a terrestrial habit have retained the same foot morphology with little modification. On each foot, the five distinguished toes are grouped into two fascicles. The toes in each fascicle are bound into a flattened group of either two or three, giving each foot a
tongs
Tongs are a type of tool used to grip and lift objects instead of holding them directly with hands. There are many forms of tongs adapted to their specific use.
The first pair of tongs belongs to the Egyptians. Tongs likely started off as ...
-like appearance. On the front feet, the outer,
lateral
Lateral is a geometric term of location which may refer to:
Healthcare
*Lateral (anatomy), an anatomical direction
* Lateral cricoarytenoid muscle
* Lateral release (surgery), a surgical procedure on the side of a kneecap
Phonetics
*Lateral co ...
, group contains two toes, whereas the inner,
medial, group contains three. On the rear feet, this arrangement is reversed, the medial group containing two toes, and the lateral group three. These specialized feet allow chameleons to grip tightly onto narrow or rough branches. Furthermore, each toe is equipped with a sharp claw to afford a grip on surfaces such as bark when climbing. It is common to refer to the feet of chameleons as
didactyl or
zygodactyl
In biology, dactyly is the arrangement of digits (fingers and toes) on the hands, feet, or sometimes wings of a tetrapod animal. It comes from the Greek word δακτυλος (''dáktylos'') = "finger".
Sometimes the ending "-dactylia" is use ...
, though neither term is fully satisfactory, both being used in describing different feet, such as the zygodactyl feet of parrots or didactyl feet of sloths or ostriches, none of which is significantly like chameleon feet. Although "zygodactyl" is reasonably descriptive of chameleon foot anatomy, their foot structure does not resemble that of parrots, to which the term was first applied. As for didactyly, chameleons visibly have five toes on each foot, not two.
Some chameleons have a crest of small spikes extending along the spine from the
proximal
Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position pro ...
part of the tail to the neck; both the extent and size of the spikes vary between species and individuals. These spikes help break up the definitive outline of the chameleon, which aids it when trying to blend into a background.
Senses
Chameleons have the most distinctive eyes of any reptile. The upper and lower eyelids are joined, with only a pinhole large enough for the pupil to see through. Each eye can pivot and focus independently, allowing the chameleon to observe two different objects simultaneously. This gives them a full 360-degree arc of vision around their bodies. Prey is located using monocular
depth perception
Depth perception is the ability to perceive distance to objects in the world using the visual system and visual perception. It is a major factor in perceiving the world in three dimensions. Depth perception happens primarily due to stereopsis an ...
, not
stereopsis
Stereopsis () is the component of depth perception retrieved through binocular vision.
Stereopsis is not the only contributor to depth perception, but it is a major one. Binocular vision happens because each eye receives a different image becaus ...
.
Chameleons have the highest magnification (per size) of any vertebrate.
Like
snake
Snakes are elongated, Limbless vertebrate, limbless, carnivore, carnivorous reptiles of the suborder Serpentes . Like all other Squamata, squamates, snakes are ectothermic, amniote vertebrates covered in overlapping Scale (zoology), scales. Ma ...
s, chameleons do not have an outer or a middle
ear
An ear is the organ that enables hearing and, in mammals, body balance using the vestibular system. In mammals, the ear is usually described as having three parts—the outer ear, the middle ear and the inner ear. The outer ear consists of ...
, so there is neither an ear-opening nor an eardrum. However, chameleons are not deaf: they can detect sound frequencies in the range of 200–600 Hz.
Chameleons can see in both visible and
ultraviolet light
Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nanometer, nm (with a corresponding frequency around 30 Hertz, PHz) to 400 nm (750 Hertz, THz), shorter than that of visible light, but longer than ...
. Chameleons exposed to ultraviolet light show increased social behavior and activity levels, are more inclined to bask, feed, and reproduce as it has a positive effect on the
pineal gland
The pineal gland, conarium, or epiphysis cerebri, is a small endocrine gland in the brain of most vertebrates. The pineal gland produces melatonin, a serotonin-derived hormone which modulates sleep, sleep patterns in both circadian rhythm, circ ...
.
Feeding
All chameleons are primarily
insectivore
A robber fly eating a hoverfly
An insectivore is a carnivorous animal or plant that eats insects. An alternative term is entomophage, which can also refer to the human practice of eating insects.
The first vertebrate insectivores wer ...
s that feed by
ballistically projecting their long
tongue
The tongue is a muscular organ (anatomy), organ in the mouth of a typical tetrapod. It manipulates food for mastication and swallowing as part of the digestive system, digestive process, and is the primary organ of taste. The tongue's upper surfa ...
s from their mouths to capture prey located some distance away.
While the chameleons' tongues are typically thought to be one and a half to two times the length of their bodies (their length excluding the tail), smaller chameleons (both smaller species and smaller individuals of the same species) have recently been found to have proportionately larger tongue apparatuses than their larger counterparts.
Thus, smaller chameleons are able to project their tongues greater distances than the larger chameleons that are the subject of most studies and tongue length estimates, and can project their tongues more than twice their body length.
The tongue apparatus consists of highly modified
hyoid bones,
tongue muscles, and
collagenous elements.
The hyoid bone has an elongated, parallel-sided projection, called the entoglossal process, over which a tubular muscle, the accelerator muscle, sits.
The accelerator muscle contracts around the entoglossal process and is responsible for creating the work to power tongue projection, both directly and through the loading of collagenous elements located between the entoglossal process and the accelerator muscle.
The tongue retractor muscle, the hyoglossus, connects the hyoid and accelerator muscle, and is responsible for drawing the tongue back into the mouth following tongue projection.
Tongue projection occurs at extremely high performance, reaching the prey in as little as 0.07 seconds,
having been launched at accelerations exceeding 41
''g''.
The
power
Power most often refers to:
* Power (physics), meaning "rate of doing work"
** Engine power, the power put out by an engine
** Electric power
* Power (social and political), the ability to influence people or events
** Abusive power
Power may a ...
with which the tongue is launched, known to exceed 3000 W kg
−1, exceeds that which muscle is able to produce, indicating the presence of an elastic power amplifier to power tongue projection.
The recoil of elastic elements in the tongue apparatus is thus responsible for large percentages of the overall tongue projection performance.
One consequence of the incorporation of an elastic recoil mechanism to the tongue projection mechanism is relative thermal insensitivity of tongue projection relative to tongue retraction, which is powered by muscle contraction alone, and is heavily thermally sensitive.
While other
ectothermic animals become sluggish as their body temperatures decline, due to a reduction in the contractile velocity of their muscles, chameleons are able to project their tongues at high performance even at low body temperatures.
The thermal sensitivity of tongue retraction in chameleons, however, is not a problem, as chameleons have a very effective mechanism of holding onto their prey once the tongue has come into contact with it, including surface phenomena, such as wet adhesion and interlocking, and suction.
The thermal insensitivity of tongue projection thus enables chameleons to feed effectively on cold mornings prior to being able to behaviorally elevate their body temperatures through
thermoregulation
Thermoregulation is the ability of an organism to keep its body temperature within certain boundaries, even when the surrounding temperature is very different. A thermoconforming organism, by contrast, simply adopts the surrounding temperature ...
, when other
sympatric
In biology, two related species or populations are considered sympatric when they exist in the same geographic area and thus frequently encounter one another. An initially interbreeding population that splits into two or more distinct species sh ...
lizards species are still inactive, likely temporarily expanding their thermal
niche
Niche may refer to:
Science
*Developmental niche, a concept for understanding the cultural context of child development
*Ecological niche, a term describing the relational position of an organism's species
*Niche differentiation, in ecology, the ...
as a result.
File:Chameleon gab fbi.png, Tongue structure, with cup-like end
File:Chameleon-Stage 04.jpg, Tongue begins strike
File:Chameleon-Stage 03.jpg, Capturing prey
File: Chameleon-Stage 01.jpg, Bringing prey to the mouth
Bones
Certain species of chameleons have bones that glow when under
ultraviolet light
Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nanometer, nm (with a corresponding frequency around 30 Hertz, PHz) to 400 nm (750 Hertz, THz), shorter than that of visible light, but longer than ...
, also known as
biogenic fluorescence
Fluorescence is the emission of light by a substance that has absorbed light or other electromagnetic radiation. It is a form of luminescence. In most cases, the emitted light has a longer wavelength, and therefore a lower photon energy, tha ...
.
Some 31 different species of ''Calumma'' chameleons, all native to
Madagascar
Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa ...
, displayed this fluorescence in
CT scans.
The bones emitted a bright blue glow and could even shine through the chameleon's four layers of skin.
The face was found to have a different glow, appearing as dots otherwise known as
tubercle
In anatomy, a tubercle (literally 'small tuber', Latin for 'lump') is any round nodule, small eminence, or warty outgrowth found on external or internal organs of a plant or an animal.
In plants
A tubercle is generally a wart-like projection ...
s on facial bones.
The glow results from
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...
s,
pigments
A pigment is a colored material that is completely or nearly insoluble in water. In contrast, dyes are typically soluble, at least at some stage in their use. Generally dyes are often organic compounds whereas pigments are often inorganic compoun ...
,
chitin
Chitin ( C8 H13 O5 N)n ( ) is a long-chain polymer of ''N''-acetylglucosamine, an amide derivative of glucose. Chitin is probably the second most abundant polysaccharide in nature (behind only cellulose); an estimated 1 billion tons of chit ...
, and other materials that make up a chameleon's skeleton,
possibly giving chameleons a secondary signaling system that does not interfere with their color-changing ability, and may have evolved from
sexual selection
Sexual selection is a mode of natural selection in which members of one biological sex mate choice, choose mates of the other sex to mating, mate with (intersexual selection), and compete with members of the same sex for access to members of t ...
.
Distribution and habitat
![Minute leaf chameleon (Brookesia minima) Lokobe](https://upload.wikimedia.org/wikipedia/commons/3/34/Minute_leaf_chameleon_%28Brookesia_minima%29_Lokobe.jpg)
Chameleons primarily live in the mainland of
sub-Saharan Africa
Sub-Saharan Africa is, geographically, the area and regions of the continent of Africa that lies south of the Sahara. These include West Africa, East Africa, Central Africa, and Southern Africa. Geopolitically, in addition to the List of sov ...
and on the island of Madagascar, although a few species live in
northern Africa
North Africa, or Northern Africa is a region encompassing the northern portion of the African continent. There is no singularly accepted scope for the region, and it is sometimes defined as stretching from the Atlantic shores of Mauritania in t ...
,
southern Europe
Southern Europe is the southern regions of Europe, region of Europe. It is also known as Mediterranean Europe, as its geography is essentially marked by the Mediterranean Sea. Definitions of Southern Europe include some or all of these countrie ...
(Portugal, Spain, Italy, Greece), the
Middle East
The Middle East ( ar, الشرق الأوسط, ISO 233: ) is a geopolitical region commonly encompassing Arabian Peninsula, Arabia (including the Arabian Peninsula and Bahrain), Anatolia, Asia Minor (Asian part of Turkey except Hatay Pro ...
, southern
India
India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...
,
Sri Lanka
Sri Lanka (, ; si, ශ්රී ලංකා, Śrī Laṅkā, translit-std=ISO (); ta, இலங்கை, Ilaṅkai, translit-std=ISO ()), formerly known as Ceylon and officially the Democratic Socialist Republic of Sri Lanka, is an ...
, and several smaller islands in the
western Indian Ocean.
Chameleons inhabit all kinds of
tropical
The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in
the Southern Hemisphere at S. The tropics are also referred to ...
and mountain
rain forest
Rainforests are characterized by a closed and continuous tree canopy, moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforest can be classified as tropical rainforest or temperate rainforest ...
s,
savanna
A savanna or savannah is a mixed woodland-grassland (i.e. grassy woodland) ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to ...
s, and sometimes
desert
A desert is a barren area of landscape where little precipitation occurs and, consequently, living conditions are hostile for plant and animal life. The lack of vegetation exposes the unprotected surface of the ground to denudation. About on ...
s and
steppe
In physical geography, a steppe () is an ecoregion characterized by grassland plains without trees apart from those near rivers and lakes.
Steppe biomes may include:
* the montane grasslands and shrublands biome
* the temperate grasslands, ...
s. The typical chameleons from the subfamily Chamaeleoninae are
arboreal
Arboreal locomotion is the Animal locomotion, locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally, but others are exclusively arboreal. Th ...
, usually living in trees or bushes, although a few (notably the
Namaqua chameleon) are partially or largely
terrestrial
Terrestrial refers to things related to land or the planet Earth.
Terrestrial may also refer to:
* Terrestrial animal, an animal that lives on land opposed to living in water, or sometimes an animal that lives on or near the ground, as opposed to ...
. Most species from the subfamily Brookesiinae, which includes the genera ''
Brookesia
''Brookesia'' is a genus of chameleons, endemic to Madagascar, that range from small to very small in size, and are known collectively as leaf chameleons (though this name also commonly is used for species in the genera ''Rieppeleon'' and ''Rham ...
'', ''
Rieppeleon
''Rieppeleon'' is a genus of small, typically brown chameleons found in forests and savannas in central East Africa (extending slightly into adjacent DR Congo). They are found at low levels in bushes, or on the ground among grass or leaf litter.
...
'', and ''
Rhampholeon
''Rhampholeon'' is a genus of small chameleons, commonly known as pygmy chameleons or African leaf chameleons, found in central East Africa (extending slightly into adjacent DR Congo). They are found in forests, woodlands, thickets, and savanna, ...
'', live low in vegetation or on the ground among
leaf litter
Plant litter (also leaf litter, tree litter, soil litter, litterfall or duff) is dead plant material (such as leaves, bark, needles, twigs, and cladodes) that have fallen to the ground. This detritus or dead organic material and its constituent ...
. Many species of chameleons are threatened by extinction. Declining chameleon numbers are due to habitat loss.
Reproduction
Chameleons are mostly
oviparous, with some being
ovoviviparous
Ovoviviparity, ovovivipary, ovivipary, or aplacental viviparity is a term used as a "bridging" form of reproduction between egg-laying oviparous and live-bearing viviparous reproduction. Ovoviviparous animals possess embryos that develop insi ...
.
The oviparous species lay eggs three to six weeks after
copulation
Sexual intercourse (or coitus or copulation) is a sexual activity typically involving the insertion and thrusting of the penis into the vagina for sexual pleasure or reproduction.Sexual intercourse most commonly means penile–vaginal penetra ...
. The female will dig a hole—from , deep depending on the species—and deposit her eggs. Clutch sizes vary greatly with species. Small ''
Brookesia
''Brookesia'' is a genus of chameleons, endemic to Madagascar, that range from small to very small in size, and are known collectively as leaf chameleons (though this name also commonly is used for species in the genera ''Rieppeleon'' and ''Rham ...
'' species may only lay two to four eggs, while large
veiled chameleon
The veiled chameleon (''Chamaeleo calyptratus'') is a species of chameleon (family Chamaeleonidae) native to the Arabian Peninsula in Yemen and Saudi Arabia. Other common names include cone-head chameleon and Yemen chameleon. They are born pas ...
s (''Chamaeleo calyptratus'') have been known to lay clutches of 20–200 (veiled chameleons) and 10–40 (panther chameleons) eggs. Clutch sizes can also vary greatly among the same species. Eggs generally hatch after four to 12 months, again depending on the species. The eggs of
Parson's chameleon (''Calumma parsonic''), a species that is rare in captivity, are believed to take more than 24 months to hatch.
Chameleons lay flexible-shelled eggs which are affected by environmental characteristics during incubation. The egg mass is the most important in differentiating survivors of Chameleon during incubation. An increase in egg mass will depend on temperature and water potential. To understand the dynamics of water potential in Chameleon eggs, the consideration of exerted pressure on eggshells will be essential because the pressure of eggshells play an important role in the water relation of eggs during entire incubation period
The
ovoviviparous
Ovoviviparity, ovovivipary, ovivipary, or aplacental viviparity is a term used as a "bridging" form of reproduction between egg-laying oviparous and live-bearing viviparous reproduction. Ovoviviparous animals possess embryos that develop insi ...
species, such as the
Jackson's chameleon
Jackson's chameleon (''Trioceros jacksonii''), also known as Jackson's horned chameleon, three-horned chameleon or Kikuyu three-horned chameleon, is a species of chameleon (family Chamaeleonidae) native to East Africa, but also introduced to Haw ...
(''Trioceros jacksonii'') have a five- to seven-month gestation period. Each young chameleon is born within the sticky transparent membrane of its yolk sac. The mother presses each egg onto a branch, where it sticks. The membrane bursts and the newly hatched chameleon frees itself and climbs away to hunt for itself and hide from predators. The female can have up to 30 live young from one gestation.
Diet
Chameleons generally eat
insect
Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pairs ...
s, but larger species, such as the common chameleon, may also take other lizards and young
bird
Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweigh ...
s.
The range of diets can be seen from the following examples:
* The veiled chameleon, ''
Chamaeleo calyptratus
''Chamaeleo'' is a genus of chameleons in the family Chamaeleonidae. Most species of the genus ''Chamaeleo'' are found in sub-Saharan Africa, but a few species are also present in northern Africa, southern Europe, and southern Asia east to Indi ...
'' from
Arabia
The Arabian Peninsula, (; ar, شِبْهُ الْجَزِيرَةِ الْعَرَبِيَّة, , "Arabian Peninsula" or , , "Island of the Arabs") or Arabia, is a peninsula of Western Asia, situated northeast of Africa on the Arabian Plate. ...
, is insectivorous, but eats leaves when other sources of water are not available. It can be maintained on a diet of
crickets
Crickets are orthopteran insects which are related to bush crickets, and, more distantly, to grasshoppers. In older literature, such as Imms,Imms AD, rev. Richards OW & Davies RG (1970) ''A General Textbook of Entomology'' 9th Ed. Methuen 8 ...
.
They can eat as many as 15–50 large crickets a day.
* Jackson's chameleon (''
Trioceros jacksonii'') from Kenya and northern Tanzania eat a wide variety of small animals including ants, butterflies, caterpillars, snails, worms, lizards, geckos, amphibians, and other chameleons, as well as plant material, such as leaves, tender shoots, and berries. It can be maintained on a mixed diet including kale, dandelion leaves, lettuce, bananas, tomatoes, apples, crickets, and waxworms.
[
* The common chameleon of Europe, North Africa, and the Near East, '' Chamaeleo chamaeleon'', mainly eats ]wasp
A wasp is any insect of the narrow-waisted suborder Apocrita of the order Hymenoptera which is neither a bee nor an ant; this excludes the broad-waisted sawflies (Symphyta), which look somewhat like wasps, but are in a separate suborder. Th ...
s and mantis
Mantises are an order (Mantodea) of insects that contains over 2,400 species in about 460 genera in 33 families. The largest family is the Mantidae ("mantids"). Mantises are distributed worldwide in temperate and tropical habitats. They ha ...
es; such arthropod
Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a Segmentation (biology), segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and Arth ...
s form over three-quarters of its diet. Some experts advise that the common chameleon should not be fed exclusively on crickets; these should make up no more than half the diet, with the rest a mixture of waxworm
Waxworms are the caterpillar larvae of wax moths, which belong to the family Pyralidae (snout moths). Two closely related species are commercially bred – the lesser wax moth (''Achroia grisella'') and the greater wax moth (''Galleria ...
s, earthworm
An earthworm is a terrestrial invertebrate that belongs to the phylum Annelida. They exhibit a tube-within-a-tube body plan; they are externally segmented with corresponding internal segmentation; and they usually have setae on all segments. Th ...
s, grasshoppers, flies
Flies are insects of the order Diptera, the name being derived from the Greek δι- ''di-'' "two", and πτερόν ''pteron'' "wing". Insects of this order use only a single pair of wings to fly, the hindwings having evolved into advanced m ...
, and plant materials such as green leaves, oats, and fruit.
* Some chameleons like the panther chameleon
The panther chameleon (''Furcifer pardalis'') is a species of chameleon found in the eastern and northern parts of Madagascar in a tropical forest biome. Additionally, it has been Introduced species, introduced to Réunion and Mauritius.
Taxono ...
of Madagascar
Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa ...
regulate their vitamin D3
Cholecalciferol, also known as vitamin D3 and colecalciferol, is a type of vitamin D that is made by the skin when exposed to sunlight; it is found in some foods and can be taken as a dietary supplement.
Cholecalciferol is made in the skin f ...
levels, of which their insect diet is a poor source, by exposing themselves to sunlight
Sunlight is a portion of the electromagnetic radiation given off by the Sun, in particular infrared, visible, and ultraviolet light. On Earth, sunlight is scattered and filtered through Earth's atmosphere, and is obvious as daylight when t ...
since its UV component increases internal production.
Anti-predator adaptations
Chameleons are preyed upon by a variety of other animals. Birds
Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweigh ...
and snakes
Snakes are elongated, limbless, carnivorous reptiles of the suborder Serpentes . Like all other squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales. Many species of snakes have skulls with several more joi ...
are the most important predators
Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill th ...
of adult chameleons. Invertebrates, especially ants, put a high predation pressure on chameleon eggs and juveniles. Chameleons are unlikely to be able to flee from predators and rely on crypsis as their primary defense. Chameleons can change both their colors and their patterns (to varying extents) to resemble their surroundings or disrupt the body outline and remain hidden from a potential enemy's sight. Only if detected, chameleons actively defend themselves. They adopt a defensive body posture, present an attacker with a laterally flattened body to appear larger, warn with an open mouth, and, if needed, utilize feet and jaws to fight back. Vocalization is sometimes incorporated into threat displays.
File:Chameleon in malawi 2018-6.webm, (video) Chameleon in Malawi
Malawi (; or aláwi Tumbuka: ''Malaŵi''), officially the Republic of Malawi, is a landlocked country in Southeastern Africa that was formerly known as Nyasaland. It is bordered by Zambia to the west, Tanzania to the north and northeast ...
File:Chameleon, Mysore.jpg, Chameleon found in Mysore
Mysore (), officially Mysuru (), is a city in the southern part of the state of Karnataka, India. Mysore city is geographically located between 12° 18′ 26″ north latitude and 76° 38′ 59″ east longitude. It is located at an altitude of ...
, Southern India
File:Chamaeleo chamaeleon Frightened thus black.JPG, This common chameleon (''Chamaeleo chamaeleon'') turned black.
File: Chameleon-Boomslang-Interaction P Berg.jpg, alt=A flap-necked chameleon defending itself against a boomslang attack, A flap-necked chameleon, ''Chamaeleo dilepis'', attacked by a boomslang while crossing a road in Namibia adopts a threatening defense posture.
File: Chamaeleo namaquensis (Namib-Naukluft, 2011).jpg, Namaqua chameleon in threat display
Deimatic behaviour or startle display means any pattern of bluffing behaviour in an animal that lacks strong defences, such as suddenly displaying conspicuous eyespots, to scare off or momentarily distract a predator, thus giving the prey anima ...
, Namib-Naukluft National Park
The Namib-Naukluft Park is a national park in western Namibia, situated between the coast of the Atlantic Ocean and the edge of the Great Escarpment. It encompasses part of the Namib Desert (considered the world's oldest desert), the Naukluft mo ...
, turned black and opened its mouth when an attempt was made to move it off a busy road.
Parasites
Chameleons are parasitized by nematode
The nematodes ( or grc-gre, Νηματώδη; la, Nematoda) or roundworms constitute the phylum Nematoda (also called Nemathelminthes), with plant-Parasitism, parasitic nematodes also known as eelworms. They are a diverse animal phylum inhab ...
worms, including threadworms (Filarioidea
The Filarioidea are a superfamily of highly specialised parasitic nematodes. Species within this superfamily are known as filarial worms or filariae (singular filaria). Infections with parasitic filarial worms cause disease conditions generica ...
). Threadworms can be transmitted by biting insects such as ticks
Ticks (order Ixodida) are parasitic arachnids that are part of the mite superorder Parasitiformes. Adult ticks are approximately 3 to 5 mm in length depending on age, sex, species, and "fullness". Ticks are external parasites, living by ...
and mosquitoes
Mosquitoes (or mosquitos) are members of a group of almost 3,600 species of small Diptera, flies within the family Culicidae (from the Latin ''culex'' meaning "gnat"). The word "mosquito" (formed by ''mosca'' and diminutive ''-ito'') is Spanish ...
. Other roundworms are transmitted through food contaminated with roundworm eggs; the larvae burrow through the wall of the intestine into the bloodstream.
Chameleons are subject to several protozoan parasites, such as ''Plasmodium'', which causes malaria
Malaria is a mosquito-borne infectious disease that affects humans and other animals. Malaria causes symptoms that typically include fever, tiredness, vomiting, and headaches. In severe cases, it can cause jaundice, seizures, coma, or death. S ...
, ''Trypanosoma'', which causes sleeping sickness
African trypanosomiasis, also known as African sleeping sickness or simply sleeping sickness, is an insect-borne parasitic infection of humans and other animals. It is caused by the species ''Trypanosoma brucei''. Humans are infected by two typ ...
, and ''Leishmania'', which causes leishmaniasis.[
Chameleons are subject to parasitism by ]coccidia
Coccidia (Coccidiasina) are a subclass of microscopic, spore-forming, single-celled obligate intracellular parasites belonging to the apicomplexan class Conoidasida.
As obligate intracellular parasites, they must live and reproduce within an a ...
,[Le Berre and Bartlett, p. 109] including species of the genera ''Choleoeimeria
''Choleoeimeria'' is a genus of alveolate parasites that infect the biliary tracts of reptiles. Morphologically they are similar to the ''Eimeria'', to whom they are closely related. The genus was described in 1989 by Paperna and Landsberg.
Gen ...
'', ''Eimeria
''Eimeria'' is a genus of apicomplexan parasites that includes various species capable of causing the disease coccidiosis in animals such as cattle, poultry and smaller ruminants including sheep and goats. ''Eimeria'' species are considered to be ...
'', and ''Isospora
''Isospora'' is a genus of internal parasites in the subclass Coccidia.
It is responsible for the condition isosporiasis, which causes acute, non-bloody diarrhoea in immunocompromised individuals.
Taxonomy
At least 248 species were originall ...
''.
As pets
Chameleons are popular reptile pets mostly imported from African countries like Madagascar, Tanzania, and Togo. The most common in the trade are the Senegal chameleon (''Chamaeleo senegalensis''), veiled chameleon (''Chamaeleo calyptratus''), panther chameleon (''Furcifer pardalis''), and Jackson's chameleon (''Trioceros jacksonii''). The U.S. has been the main importer of chameleons since the early 1980s accounting for 69% of African reptile exports. However, there have been large declines due to tougher regulations to protect species from being taken from the wild and due to many becoming invasive in places like Florida. They have remained popular though which may be due to the captive-breeding in the U.S. which has increased to the point that the U.S. can fulfill its demand, and has now even become a major exporter as well. In the U.S. they are so popular, that despite Florida having six invasive chameleon species due to the pet trade, reptile hobbyists in these areas search for chameleons to keep as pets or to breed and sell them, with some selling for up to a thousand dollars.
Historical understandings
Aristotle
Aristotle (; grc-gre, Ἀριστοτέλης ''Aristotélēs'', ; 384–322 BC) was a Greek philosopher and polymath during the Classical period in Ancient Greece. Taught by Plato, he was the founder of the Peripatetic school of phil ...
(4th century BC) describes chameleons in his History of Animals
''History of Animals'' ( grc-gre, Τῶν περὶ τὰ ζῷα ἱστοριῶν, ''Ton peri ta zoia historion'', "Inquiries on Animals"; la, Historia Animalium, "History of Animals") is one of the major texts on biology by the ancient Gr ...
. Pliny the Elder
Gaius Plinius Secundus (AD 23/2479), called Pliny the Elder (), was a Roman author, naturalist and natural philosopher, and naval and army commander of the early Roman Empire, and a friend of the emperor Vespasian. He wrote the encyclopedic '' ...
(1st century AD) also discusses chameleons in his Natural History, noting their ability to change color for camouflage.
The chameleon was featured in Conrad Gessner's ''Historia animalium'' (1563), copied from ''De aquatilibus'' (1553) by Pierre Belon
Pierre Belon (1517–1564) was a French traveller, naturalist, writer and diplomat. Like many others of the Renaissance period, he studied and wrote on a range of topics including ichthyology, ornithology, botany, comparative anatomy, architectur ...
.
In Shakespeare's ''Hamlet'', the eponymous Prince says "Excellent, i' faith, of the chameleon's dish. I eat the air, promise-crammed." This refers to the Elizabethan belief that chameleons lived on nothing but the air.
References
General bibliography
* Le Berre, François; Bartlett, Richard D. (2009). ''The Chameleon Handbook''. Barron's Educational Series. 3rd Edition. .
Further reading
*
*
*
*
* Davison, Linda J. ''Chameleons: Their Care and Breeding.'' Hancock House Publishers, 1997.
*
* de Vosjoli, Philippe. ''Essential Care of Chameleons.'' Advanced Vivarium Systems, 2004.
*
External links
*
*
{{Authority control
Lizards of Africa
Afrotropical realm fauna
Articles containing video clips
Extant Paleocene first appearances
Taxa named by Constantine Samuel Rafinesque