Left: the Mourning Chained Gecko
(Lepidodactylus lugubris) reproduces
solely by parthenogenesis, and is a
formidable colonist.
Image by Peter Yeeles.
Right: Bynoe’s Gecko (Heteronotia
binoei) is actually a species complex
including parthenogenetic and
sexually-reproducing races that live
side by side. Image by JennyKS.
Creative Commons Attribution-Share Alike 3.0
Unported License.
Below: Prairie Racerunner
(Aspidoscelis sexlineatus viridis). The
whiptail lizards belonging to the
genera Cnemidophorus and
Aspidoscelis are perhaps the most
famous examples of parthenogenesis
in reptiles. Image by Creeping Things.
accepted, this indicated that all skin colour classes of
A. dixoni arose from a single origin, and the three colour
classes are the result of mutation occurring within the
same unisexual species.
which are not dependent upon high humidity for
development.
Similar attributes have allowed parthenogenetic organisms
to become formidable colonists. A single female is all that
Bynoe’s Gecko (Heteronotia binoei) is widespread across is required to start up a whole new population in a new
much of Australia, and has been heralded as the ‘most
location. The Mourning Chained Gecko (Lepidodactylus
successful of parthenogenetic vertebrates’. In reality, this lugubris) is widespread across the Pacific and Indian
appears to comprise a species complex, consisting of three Oceans. It has been introduced to Hawaii and parts of
distinct sexually-reproducing races that often coexist
Central and South America, and also possibly to
alongside a triploid parthenogenetic variety. Triploid
Australia, where it can be found in the islands of Torres
asexual H. binoei are larger than their diploid counter-
Strait, Darwin, and parts of coastal Queensland. Both
parts, but otherwise appear to lack the hybrid vigour that
diploid and triploid females exist, along with the
might be expected, although they have increased tolerance occasional male, but these have been shown to be sexually
for cold. Despite being genetically identical, striking
impaired. The Mourning Chained Gecko prefers to inhabit
variation in colour, pattern and scalation has been
human structures in coastal areas, thereby increasing the
observed. The parthenogenetic race is better placed to
chance of hitching a ride and further extending its domain.
exploit favourable environment conditions, as every
Likewise, Nactus pelagicus, another small gecko with
individual is potentially reproductive, and this ensures
parthenogenetic populations, has managed to colonise
rapid expansion and dispersal. Unlike many other
many islands in the Pacific. The clear advantage of
Australian geckos, H. binoei also has hard-shelled eggs
parthenogenesis can be seen in the almost universal
‘
‘
Perhaps the best-known example of obligate
parthenogenesis in reptiles occurs amongst
whiptail lizards native to the southern United
States and Central America.