Eulamprus Quoyii
   HOME

TheInfoList



OR:

''Eulamprus quoyii'', more commonly known as the eastern water skink, eastern water-skink, or golden water skink, is a
viviparous In animals, viviparity is development of the embryo inside the body of the mother, with the maternal circulation providing for the metabolic needs of the embryo's development, until the mother gives birth to a fully or partially developed juve ...
species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...
of diurnal
skink Skinks are a type of lizard belonging to the family (biology), family Scincidae, a family in the Taxonomic rank, infraorder Scincomorpha. With more than 1,500 described species across 100 different taxonomic genera, the family Scincidae is one o ...
. ''Eulamprus quoyii'' belongs to the family Scincidae and is considered a common garden animal in Australia. The skink is
endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...
to
Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...
and found only along the east coast of the country. It makes its home in creekside
habitat In ecology, habitat refers to the array of resources, biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species' habitat can be seen as the physical manifestation of its ...
s along the east coast of Australia and in
urban Urban means "related to a city". In that sense, the term may refer to: * Urban area, geographical area distinct from rural areas * Urban culture, the culture of towns and cities Urban may also refer to: General * Urban (name), a list of people ...
garden areas with high amounts of moisture. The species can be identified by the twin, long yellow stripes that run along its body from the top of the eye, as well as by several more specific character derived states. The pale yellow dorsolateral stripes are most likely where its common name, the golden water skink, is derived. Like other
ectotherms An ectotherm (), more commonly referred to as a "cold-blooded animal", is an animal in which internal physiological sources of heat, such as blood, are of relatively small or of quite negligible importance in controlling body temperature.Daven ...
, the skink can often be seen basking in the sun on rocky outcroppings in order to regulate its body temperature. Its diet mainly consists of both
aquatic Aquatic means relating to water; living in or near water or taking place in water; does not include groundwater, as "aquatic" implies an environment where plants and animals live. Aquatic(s) may also refer to: * Aquatic animal, either vertebrate ...
and
terrestrial Terrestrial refers to things related to land or the planet Earth, as opposed to extraterrestrial. 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 o ...
insects, tadpoles and small amounts of plant matter. The skink both hunts for food and scavenges when necessary and is considered an opportunistic feeder. It is prey to larger lizards, snakes, cats and birds and so will often be seen moving quickly into hiding when other organisms are present.


Etymology

The
genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
name ''Eulamprus'' is derived from the Latin meaning "good-beautiful". The
specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...
, ''quoyii'', is in honor of French zoologist
Jean René Constant Quoy Jean René Constant Quoy (10 November 1790 in Maillé, Vendée, Maillé – 4 July 1869 in Rochefort, Charente-Maritime, Rochefort) was a French naval surgeon, zoologist and anatomist. In 1806, he began his medical studies at the school of naval ...
.Beolens, Bo; Watkins, Michael; Grayson, Michael (2011). ''The Eponym Dictionary of Reptiles''. Baltimore:Johns Hopkins University Press. xiii + 296 pp. . (''Eulamprus quoyii'', p. 214).


Taxonomy

''Eulamprus quoyii'' belongs to the genus ''
Eulamprus ''Eulamprus'' is a genus of lizards, commonly known as water skinks, in the subfamily Sphenomorphinae of the family Scincidae. The genus is native to Australia. Taxonomy The genus ''Eulamprus'' belongs to a clade in the ''Sphenomorphus'' grou ...
'' which is a part of the subfamily
Lygosominae Lygosominae is the largest subfamily of skinks in the family Scincidae. The subfamily can be divided into a number of genus groups. If the rarely used taxonomic rank of infrafamily is employed, the genus groups would be designated as such, but s ...
of the family Scincidae. The genus, among others such as ''
Ctenotus ''Ctenotus'' is a genus of skinks, lizards in the family Scincidae. The genus is endemic to Australia. The genus ''Ctenotus'' belongs to a clade in the ''Sphenomorphus'' group which contains such genera as '' Anomalopus'' and the close relatives ...
'' and '' Anomalopus'', falls within a
clade In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...
in the
Sphenomorphus The genus ''Sphenomorphus'' – vernacularly also known as the common skinks – currently serves as a "wastebin taxon" for numerous skinks. While most or all species presently placed here are probably rather close relatives, the genus ...
group.
Phylogenetic In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical dat ...
research into the genus revealed that the ''Eulamprus'' assigned species were four independent lineages, causing the ''Eulamprus'' genus to be confined to water skinks alone. Other species previously categorised within the ''Eulamprus'' genus were assigned to ''
Concinnia ''Concinnia'' is a genus of skinks in the subfamily Sphenomorphinae. Taxonomy and systematics The genus ''Concinnia'' belongs to the Australian Sphenomorphid clade that contains other genera such as ''Ctenotus'', '' Anomalopus'' and the ''Eulam ...
'', ''
Silvascincus ''Silvascincus'' is a genus of skinks, lizards in the family Scincidae. Both species in the genus are endemic to Australia. They were previously placed in the genus '' Eulamprus''. Species The following two species, listed alphabetically by spe ...
'' and '' Tumbunascincus''. ''Eulamprus quoyii'' has several derived character states which separate the species from other species within the genus. However, there are few if any differences in preferred habitat selection within the ''E. quoyii'' group, implying a strong evolutionary consequence for the species due to previous environmental changes.


Description

''Eulamprus quoyii'' is a large water skink that can grow to approximately 115mm in snout-vent length (SVL). They have sharply-defined, narrow, pale yellow dorsolateral stripes that start from above the eye and extend down the body but lack the typical black vertebral stripe of other species in the genus. Its body is medium-sized and has a long slender tail. It has a blackish upper lateral zone with pale spots and its head and snout are moderately acute. Each of its two front limbs have five fingers while the two back limbs have five toes. Its
ventral Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position prov ...
area is cream in colour with some randomly scattered darker spots that differ between individuals. Its throat is white with darker black patches. There is minor
sexual dimorphism Sexual dimorphism is the condition where sexes of the same species exhibit different Morphology (biology), morphological characteristics, including characteristics not directly involved in reproduction. The condition occurs in most dioecy, di ...
within the species resulting in the females having a slightly longer snout-vent length and the males to have proportionately longer limbs and heads. The difference in SVL between females and males is not statistically significant. There is a significant difference in shape between sexes of both adult and
neonate In common terminology, a baby is the very young offspring of adult human beings, while infant (from the Latin word ''infans'', meaning 'baby' or 'child') is a formal or specialised synonym. The terms may also be used to refer to Juvenile (orga ...
''E. quoyii''. In adult male water skinks the distance between the forelimbs and hindlimbs, or the trunk length, are typically shorter than females. Males are known to have longer limbs, wider heads and a greater mass than females of the species. In male ''E. quoyii'' specimens; forelimb length, head width and overall mass all increase significantly more quickly with increased SVL growth than in females. However, this does not apply to hindlimbs or trunk length which both increase at the same rate in females and males as the SVL increases. In neonates, body shape is much more similar between the sexes with the exception of the female trunk length which is significantly longer than the male counterparts. Within the ''Eulamprus'' complex several features are shared by all species including ''E. quoyii''. Individual organisms' nasal passages are separated
medially Medial may refer to: Mathematics * Medial magma, a mathematical identity in algebra Geometry * Medial axis, in geometry the set of all points having more than one closest point on an object's boundary * Medial graph, another graph that repr ...
while they do not have any supranasal and postnasal scales. Individuals have two subequal
lore Lore may refer to: * Folklore, acquired knowledge or traditional beliefs * Oral lore or oral tradition, orally conveyed cultural knowledge and traditions Places * Loré, former French commune * Loré (East Timor), a city and subdistrict in La ...
al scales and a single
preocular scale In scaled reptiles, the ocular scales are those forming the margin of the eye.Wright AH, Wright AA. 1957. ''Handbook of Snakes''. Comstock Publishing Associates (7th printing, 1985). 1105 pp. . The name originates from the term which is Latin f ...
with a moveable lower scaly eyelid. The iris and pupil are both black and are indistinguishable from each other during the skinks life. The Eastern water skink has three presubocular scales, one of which penetrates downwards in front of the scales on the upper lip and upper jaw. The ''Eulamprus'' species show two or three scales beneath the eye and four above the eye, these are called
subocular In scaled reptiles, the ocular scales are those forming the margin of the eye.Wright AH, Wright AA. 1957. ''Handbook of Snakes''. Comstock Publishing Associates (7th printing, 1985). 1105 pp. . The name originates from the term which is Latin f ...
and
supraocular In scaled reptiles, supraocular scales are (enlarged) scales on the crown immediately above the eye.Mallow D, Ludwig D, Nilson G. 2003. True Vipers: Natural History and Toxinology of Old World Vipers. Malabar, Florida: Krieger Publishing Company. ...
scales respectively. Some of the supraoculars will be in contact the frontal scales. Two or three postocular scales lie behind but in contact with the eye and sit between the posterior supraciliary scale and the
parietal eye A parietal eye (third eye, pineal eye) is a part of the epithalamus in some vertebrates. The eye is at the top of the head; is photoreceptive; and is associated with the pineal gland, which regulates circadian rhythmicity and hormone production ...
. The ''E. quoyii'' species group specifically shares four derived character states that separate it from other species within the ''Eulamprus'' genus. The first of which is a third pair of
chin shields Chin shields or chinshields, genials scales on a snake are scales found on the underside of the snake's head towards the anterior and touching the lower labial scales. Chin shields to the front of the snake (towards the snout) are called anterio ...
separated by five smaller scales. Secondly, ''E. quoyii'' do not have inguinal fat bodies in both males and females that is commonly seen in other Scincidae species. This is what causes the species slender, elongated appearance. The third character state is the single row of distal supradigital scales seen on ''E. quoyii'' as opposed to the usual two or more rows observed in other species. Lastly, each
lamellae Lamella (: lamellae) means a small plate or flake in Latin, and in English may refer to: Biology * Lamella (mycology), a papery rib beneath a mushroom cap * Lamella (botany) * Lamella (surface anatomy), a plate-like structure in an animal * Lame ...
on the underside of the toes are grooved and divided at the base.


Behaviour


Breeding and reproduction

When ''Eulamprus quoyii'' breed, male and females of the species mate in Spring and will give birth to up to nine babies per
clutch A clutch is a mechanical device that allows an output shaft to be disconnected from a rotating input shaft. The clutch's input shaft is typically attached to a motor, while the clutch's output shaft is connected to the mechanism that does th ...
in the Summer. Unlike many other reptile species, the Eastern Water Skink is a viviparous species and will give birth to live young following their long
gestation Gestation is the period of development during the carrying of an embryo, and later fetus, inside viviparous animals (the embryo develops within the parent). It is typical for mammals, but also occurs for some non-mammals. Mammals during pregn ...
periods. Due to the length of these gestation periods, it is common for female ''E. quoyii'' individuals to mate only once a year. Male individuals differ from the females in that they can be classified into two categories: Territorial/Resident males and Floater Males. Resident males are suspected to be more active over a longer period, producing clutches with a higher yield of offspring. Floater males are predicted to have larger home ranges and move greater distances while active, leading to fewer clutches and offspring per year.
Sexual selection Sexual selection is a mechanism of evolution in which members of one 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 the opposite sex ...
in the ''E. quoyii'' species is not believed to have a direct correlation to performance and fitness traits such as bite force or speed as it does in other lizard species. Previous research has shown that there does seem to be a correlation between SVL and sexual selection in ''E. quoyii,'' however, due to the adoption of alternate reproductive tactics (ART) in the species, there is the chance that specific performance traits are correlated with other unmeasured behavioural, morphological or physiological traits.


Nesting

Depending on the urban landscape and habitat, the nesting habits of the eastern water skink will change from area to area. When found in a highly urban areas including backyards or city parks, ''E. quoyii'' will often create nests in moist soil areas and under logs or rocks in the garden, Outside of these urban areas ''E. quoyii'' have similar nesting habits to other species in the Scincidae family. Despite being ground dwellers, they have been known to nest above ground level, on sandstone outcrops in the narrow, broken crevices that are available. They choose areas with a low canopy openness in order to avoid predation and actively choose sites with lower UV radiation which still have very high humidity levels. All nesting areas are found in close proximity to small bodies of water or in areas where water and moisture are highly available. The Eastern water skink has also been known to nest in both communal and solitary nesting sites.


Diet

''Eulamprus quoyii'' are by nature opportunistic
predators Predation is a biological interaction in which 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 ...
and feed on both aquatic and terrestrial prey. Their diet consists of, but is not limited too:
water beetle A water beetle is a generalized name for any beetle that is adapted to living in water at any point in its life cycle. Most water beetles can only live in fresh water, with a few marine species that live in the intertidal zone or littoral zone. T ...
s and other aquatic insects,
snail A snail is a shelled gastropod. The name is most often applied to land snails, terrestrial molluscs, terrestrial pulmonate gastropod molluscs. However, the common name ''snail'' is also used for most of the members of the molluscan class Gas ...
s,
tadpole A tadpole or polliwog (also spelled pollywog) is the Larva, larval stage in the biological life cycle of an amphibian. Most tadpoles are fully Aquatic animal, aquatic, though some species of amphibians have tadpoles that are terrestrial animal, ...
s, spiders, small fish and smaller lizards. The Eastern water skink has also been known to feed on native fruit and other plant materials when available. Like others in the Scincidae family, Eastern Water Skinks have no need to eat every day but will do so when the conditions are favourable. Their range of dietary options for are extensive due to favourable habitat selection factors and the presence of small bodies of water in their chosen habitats. This leads to a more active
ecosystem An ecosystem (or ecological system) is a system formed by Organism, organisms in interaction with their Biophysical environment, environment. The Biotic material, biotic and abiotic components are linked together through nutrient cycles and en ...
and offers a wider variety of food options available for both scavenging and predation by the skink.


Predation

''E. quoyii'' are both predators and
scavengers Scavengers are animals that consume dead organisms that have died from causes other than predation or have been killed by other predators. While scavenging generally refers to carnivores feeding on carrion, it is also a herbivorous feeding ...
when meeting their own dietary requirements. They are known to also be prey to a number of larger terrestrial organisms such as birds, big lizards, snakes, turtles and cats. A common predator of the Eastern Water Skink is the Australian Laughing Kookaburra, ''Dacelo novaeguineae''. It is unknown whether the Eastern Water Skink is also preyed upon by any larger aquatic animals, yet it is suspected that
crayfish Crayfish are freshwater crustaceans belonging to the infraorder Astacidea, which also contains lobsters. Taxonomically, they are members of the superfamilies Astacoidea and Parastacoidea. They breathe through feather-like gills. Some spe ...
are a minor predator of the species. The eastern water skink has strong behavioural tendencies towards
flight Flight or flying is the motion (physics), motion of an Physical object, object through an atmosphere, or through the vacuum of Outer space, space, without contacting any planetary surface. This can be achieved by generating aerodynamic lift ass ...
when provoked or threatened by predators. Despite the territorial nature of some males, due to the relative body size of the species and the high number of predators in waterside habitats, the skink is known to race away from basking sites at the first sense of danger.


Habitat

The Eastern Water Skink can be found in creekside habitats,
estuaries An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environm ...
or near small to medium-sized bodies of water as well as in moist urban garden areas along Australia's East Coast cities. Outside of the urban environment, ''E. quoyii''
population densities Population density (in agriculture: standing stock or plant density) is a measurement of population per unit land area. It is mostly applied to humans, but sometimes to other living organisms too. It is a key geographical term.Matt RosenberPopul ...
are highest in open, rocky creek areas compared to creek or water areas with thick vegetation or cool forest conditions. Areas with rocky outcroppings and high availability of sunlight have a direct correlation with the abundance of ''E. quoyii'' populations. ''E. quoyii'' habitat selection is not chosen through abundance or lack of outcroppings and vegetation, but is selected through
substrate Substrate may refer to: Physical layers *Substrate (biology), the natural environment in which an organism lives, or the surface or medium on which an organism grows or is attached ** Substrate (aquatic environment), the earthy material that exi ...
temperature and necessary
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 ...
factors for the species.


Distribution

As the common name implies, the Eastern Water Skink is most often found in areas along Australia's temperate east coast. They have been known to be found in the
Australian Capital Territory The Australian Capital Territory (ACT), known as the Federal Capital Territory until 1938, is an internal States and territories of Australia, territory of Australia. Canberra, the capital city of Australia, is situated within the territory, an ...
,
New South Wales New South Wales (commonly abbreviated as NSW) is a States and territories of Australia, state on the Eastern states of Australia, east coast of :Australia. It borders Queensland to the north, Victoria (state), Victoria to the south, and South ...
,
Queensland Queensland ( , commonly abbreviated as Qld) is a States and territories of Australia, state in northeastern Australia, and is the second-largest and third-most populous state in Australia. It is bordered by the Northern Territory, South Austr ...
,
South Australia South Australia (commonly abbreviated as SA) is a States and territories of Australia, state in the southern central part of Australia. With a total land area of , it is the fourth-largest of Australia's states and territories by area, which in ...
and
Victoria Victoria most commonly refers to: * Queen Victoria (1819–1901), Queen of the United Kingdom and Empress of India * Victoria (state), a state of Australia * Victoria, British Columbia, Canada, a provincial capital * Victoria, Seychelles, the capi ...
. Australia's east coast has contained temperate, moist patches of rainforest that have changed over the course of millions of years and is hypothesised to have covered a much broader area of the continent prior to the arid conditions in the mid-Miocene period. The contraction, expansion and fragmentation of these swathes of rainforest are believed to have fundamentally altered the distribution of the ''E. quoyii'' species to the current specific regions along the east coast. Through phylogenetic studies into the
mtDNA Mitochondrial DNA (mtDNA and mDNA) is the DNA located in the mitochondria organelles in a eukaryotic cell that converts chemical energy from food into adenosine triphosphate (ATP). Mitochondrial DNA is a small portion of the DNA contained in ...
sequences of the ''E. quoyii'' and a comparison of the landscape evolution in Eastern Australia their distribution is suspected to be controlled by biogeographic barriers. Breaks in their population correlate with areas where the
Great Escarpment The Great Escarpment is a major topographical feature in Africa that consists of steep slopes from the high central Southern African plateauAtlas of Southern Africa. (1984). p. 13. Reader's Digest Association, Cape Town downward in the directio ...
is absent, this suggests that topographically low areas and the accompanying dry forestry surrounding them act as a barrier for the distribution of the Eastern Water Skink populations.


References


Further reading

* Boulenger GA (1887). ''Catalogue of the Lizards in the British Museum (Natural History), Second Edition. Volume III. ... Scincidæ ...'' London: Trustees of the British Museum (Natural History). (Taylor and Francis, printers). xii + 575 pp. + Plates I-XL. (''Lygosoma quoyi'', pp. 230–231). * Duméril AMC,
Bibron G Gabriel Bibron (20 October 1805 – 27 March 1848) was a French zoologist and herpetologist. He was born in Paris. The son of an employee of the Museum national d'histoire naturelle, he had a good foundation in natural history and was hire ...
(1839). ''Erpétologie générale ou Histoire naturelle complète des Reptiles. Tome cinquième'' General Herpetology or Complete Natural History of the Reptiles. Volume 5 Paris: Roret. viii + 854 pp. (''Lygosoma quoyii'', replacement name, pp. 728–730). (in French).


External links


''Eulamprus quoyii'' Eastern Water Skink
www.WildHerps.com.
''Eulamprus quoyii''
JCU.

images of Australian flora and fauna.
''Eulamprus quoyii''
Adelaide and Mount Lofty Ranges, South Australia. {{Taxonbar, from=Q3019610 Eulamprus Skinks of Australia Endemic fauna of Australia Reptiles described in 1839 Taxa named by Gabriel Bibron Taxa named by André Marie Constant Duméril