''Calycopteryx'' is a genus of stilt-legged fly with only a single recognized species, the ''Calycopteryx mosleyi'' (sometimes misspelled ''moseleyi'') native to the

Kerguelen Islands The Kerguelen Islands ( or ; in French commonly ' but officially ', ), also known as the Desolation Islands (' in French), are a group of islands in the subantarctic, sub-Antarctic region. They are among the Extremes on Earth#Remoteness, most i ...

and

Heard Island The Territory of Heard Island and McDonald Islands (HIMI) is an Australian external territory comprising a volcanic group of mostly barren Antarctic islands, about two-thirds of the way from Madagascar to Antarctica. The group's overall land ...

of the south

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or approximately 20% of the water area of Earth#Surface, Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia (continent), ...

, first described by

Alfred Edwin Eaton Alfred Edwin Eaton (1 December 1844 – 23 March 1929) was an England, English clergyman and entomologist. He served as the vicar of Shepton Montague in Somerset. His main interests among insects were the Diptera and Ephemeroptera. Biography Fa ...

in 1875. It is characterized by its tiny size and flightlessness.

Evolution and taxonomy

''Calycopteryx mosleyi'' has

wing A wing is a type of fin that produces both Lift (force), lift and drag while moving through air. Wings are defined by two shape characteristics, an airfoil section and a planform (aeronautics), planform. Wing efficiency is expressed as lift-to-d ...

s that have shrunk and turned into a fat reserve, probably due to the strong

wind Wind is the natural movement of atmosphere of Earth, air or other gases relative to a planetary surface, planet's surface. Winds occur on a range of scales, from thunderstorm flows lasting tens of minutes, to local breezes generated by heatin ...

s of the

Kerguelen archipelago The Kerguelen Islands ( or ; in French commonly ' but officially ', ), also known as the Desolation Islands (' in French), are a group of islands in the sub-Antarctic region. They are among the most isolated places on Earth, with the closest t ...

that make flight for tiny insects almost impossible. This could indicate that they migrated from elsewhere to the islands they are currently found and evolved there separately from the other species of the family

Micropezidae The Micropezidae are a moderate-sized family of acalyptrate muscoid flies in the insect order Diptera, comprising about 500 species in about 50 genera and five subfamilies worldwide, (except New Zealand and Macquarie Island).McAlpine, D.K. (199 ...

. They are the only recognized species of the genus. Two subspecies are recognized: * ''Calycopteryx mosleyi mosleyi'' ( Eaton, 1875) * ''Calycopteryx mosleyi minor'' ( Enderlein, 1909)

Description

These tiny flies can reach 7 mm in length and have a greenish-brown color. They have very long

leg A leg is a weight-bearing and locomotive anatomical structure, usually having a columnar shape. During locomotion, legs function as "extensible struts". The combination of movements at all joints can be modeled as a single, linear element cap ...

s, which are darker than their body. Their

abdomen The abdomen (colloquially called the gut, belly, tummy, midriff, tucky, or stomach) is the front part of the torso between the thorax (chest) and pelvis in humans and in other vertebrates. The area occupied by the abdomen is called the abdominal ...

is hairless and matte brown in color. Their

larva A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, some arachnids, amphibians, or cnidarians typically have a larval phase ...

e are

maggot A maggot is the larva of a fly (order Diptera); it is applied in particular to the larvae of Brachycera flies, such as houseflies, cheese flies, hoverflies, and blowflies, rather than larvae of the Nematocera, such as mosquitoes and cr ...

s which are white in color.

Habitat and distribution

''Calycopteryx mosleyi'' lives in the

and

which are part of the

Southern Indian Ocean Islands tundra The Southern Indian Ocean Islands tundra is a tundra ecoregion that includes several subantarctic islands in the southern Indian Ocean. Location and description The ecoregion stretches from Prince Edward Islands in the west, past the Crozet ...

ecoregion An ecoregion (ecological region) is an ecological and geographic area that exists on multiple different levels, defined by type, quality, and quantity of environmental resources. Ecoregions cover relatively large areas of land or water, and c ...

. The

climate Climate is the long-term weather pattern in a region, typically averaged over 30 years. More rigorously, it is the mean and variability of meteorological variables over a time spanning from months to millions of years. Some of the meteoro ...

is classified as '' ET (tundra climate)'' under the

Köppen climate classification The Köppen climate classification divides Earth climates into five main climate groups, with each group being divided based on patterns of seasonal precipitation and temperature. The five main groups are ''A'' (tropical), ''B'' (arid), ''C'' (te ...

, which is technically a form of

polar climate The polar climate regions are characterized by a lack of warm summers but with varying winters. Every month a polar climate has an average temperature of less than . Regions with a polar climate cover more than 20% of the Earth's area. Most of ...

, as the average temperature in the warmest month is below . Apart from the cold, the climate is also characterized by extreme windswept, generally low

cloud cover Cloud cover (also known as cloudiness, cloudage, or cloud amount) refers to the fraction of the sky obscured by clouds on average when observed from a particular location. Okta is the usual unit for measurement of the cloud cover. The cloud c ...

and

snow Snow consists of individual ice crystals that grow while suspended in the atmosphere—usually within clouds—and then fall, accumulating on the ground where they undergo further changes. It consists of frozen crystalline water througho ...

fall occurrence through most of the year. Pringlea antiscorbutica Mayes fake

They are closely associated with the

Kerguelen cabbage ''Pringlea antiscorbutica'', commonly known as Kerguelen cabbage, is a flowering plant and the sole member of the monotypic genus ''Pringlea'' in the family (biology), family Brassicaceae. Its common name comes from the archipelago of its discove ...

, a plant which the individuals of the ''C. mosleyi'' are its main

pollinator A pollinator is an animal that moves pollen from the male anther of a flower to the female carpel, stigma of a flower. This helps to bring about fertilization of the ovules in the flower by the male gametes from the pollen grains. Insects are ...

s, and these flies are typically found in large numbers on the leaves of the Kerguelen cabbages across the islands of the

and

. This cabbage is a main trophic resource for both adult and larvae of the ''C. mosleyi'' and many of the flies spent most of their lives on cabbages. Kerguelen cabbages are distributed from littoral margins to further inland and are usually found in non-saline areas. This in combination with the fact that adults of ''C. mosleyi'' are found at the axil of the leaves where rainwater is accumulated and

salinity Salinity () is the saltiness or amount of salt (chemistry), salt dissolved in a body of water, called saline water (see also soil salinity). It is usually measured in g/L or g/kg (grams of salt per liter/kilogram of water; the latter is dimensio ...

is null or low, brought the attention of scientists because it makes the ''C. mosleyi'' quite exceptional among the

invertebrate Invertebrates are animals that neither develop nor retain a vertebral column (commonly known as a ''spine'' or ''backbone''), which evolved from the notochord. It is a paraphyletic grouping including all animals excluding the chordata, chordate s ...

s of subantarctic region, most of which live in environments with high levels of salinity. However, newer studies reveal that there is a large number of ''C. mosleyi'' living in areas devoid of Kerguelen cabbages, like

seaweed Seaweed, or macroalgae, refers to thousands of species of macroscopic, multicellular, marine algae. The term includes some types of ''Rhodophyta'' (red), '' Phaeophyta'' (brown) and ''Chlorophyta'' (green) macroalgae. Seaweed species such as ...

habitats consisting mostly of

kelp Kelps are large brown algae or seaweeds that make up the order (biology), order Laminariales. There are about 30 different genus, genera. Despite its appearance and use of photosynthesis in chloroplasts, kelp is technically not a plant but a str ...

s of the ''

Macrocystis pyrifera ''Macrocystis'' is a monospecific genus of kelp (large brown algae) with all species now synonymous with ''Macrocystis pyrifera''. It is commonly known as giant kelp or bladder kelp. This genus contains the largest of all the Phaeophyceae or br ...

'' species that were washed ashore. They have also been found in other coastal locations, like

penguin Penguins are a group of aquatic flightless birds from the family Spheniscidae () of the order Sphenisciformes (). They live almost exclusively in the Southern Hemisphere. Only one species, the Galápagos penguin, is equatorial, with a sm ...

colonies, where they have a similar role as in the seaweed ecosystems, they decompose organic matter.

Threats

The population of ''Calycopteryx mosleyi'' has greatly reduced since the arrival of humans on the islands it inhabits, mostly due to the animals introduced to the

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 ...

by them.

Rabbit Rabbits are small mammals in the family Leporidae (which also includes the hares), which is in the order Lagomorpha (which also includes pikas). They are familiar throughout the world as a small herbivore, a prey animal, a domesticated ...

s were brought from

South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...

to some of the islands of the

in 1874 and the following years. They have been feeding on the

ever since, resulting in reduction of its population and obviously a destruction of ''C. mosleyi's''

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 ...

in some areas. In 1913,

beetle Beetles are insects that form the Taxonomic rank, order Coleoptera (), in the superorder Holometabola. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 40 ...

s of the '' Merizodus soledadinus'' species of

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

were also introduced to the

. They prey on the

e of ''C. mosleyi'' and as a result the population of the indigenous flies has declined greatly since the beetle's introduction to the

. The ''Merizodus soledadinus'' could eventually outnumber the ''Calycopteryx mosleyi'' in some of the islands resulting in ''C. mosleyi's'' disappearance. Like most of the

fauna Fauna (: faunae or faunas) is all of the animal life present in a particular region or time. The corresponding terms for plants and fungi are ''flora'' and '' funga'', respectively. Flora, fauna, funga and other forms of life are collectively ...

of the

subantarctic The sub-Antarctic zone is a physiographic region in the Southern Hemisphere, located immediately north of the Antarctic region. This translates roughly to a latitude of between 46th parallel south, 46° and 60th parallel south, 60° south of t ...

, ''Calycopteryx mosleyi'' is also threatened by the

climate change Present-day climate change includes both global warming—the ongoing increase in Global surface temperature, global average temperature—and its wider effects on Earth's climate system. Climate variability and change, Climate change in ...

, with the rising temperature disrupting the balanced ecosystem.

References

{{Taxonbar, from=Q18109307, from2=Q14717270 Micropezidae Nerioidea genera Fauna of the Kerguelen Islands Fauna of Heard Island and McDonald Islands Monotypic Diptera genera