''Sarcophaga barbata'' is a species from the genus '' Sarcophaga'' and the family of flesh fly, ''Sarcophagidae''. It is most closely related to ''S. plinthopyga'', ''S. securifera'', and ''S. bullata'' of the same genus. The species was first discovered by Eugene Thomson in 1868. ''S. barbata'' has also been found in the

Middle East The Middle East (term originally coined in English language) is a geopolitical region encompassing the Arabian Peninsula, the Levant, Turkey, Egypt, Iran, and Iraq. The term came into widespread usage by the United Kingdom and western Eur ...

near carcasses, where the larvae can thrive. ''S. barbata'' is also a prominent organism in scientific research and has been used to study L-3-glycerophosphate

oxidation Redox ( , , reduction–oxidation or oxidation–reduction) is a type of chemical reaction in which the oxidation states of the reactants change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is ...

and location within the

mitochondria A mitochondrion () is an organelle found in the cells of most eukaryotes, such as animals, plants and fungi. Mitochondria have a double membrane structure and use aerobic respiration to generate adenosine triphosphate (ATP), which is us ...

Morphology

The body of ''S. barbata'' is grey in color, spanning from 10 to 14 mm in length. ''S. barbata'' has red compound eyes. Its

thorax The thorax (: thoraces or thoraxes) or chest is a part of the anatomy of mammals and other tetrapod animals located between the neck and the abdomen. In insects, crustaceans, and the extinct trilobites, the thorax is one of the three main di ...

displays three prominent black stripes, with another less distinct stripe on each side. Its abdomen is smaller in width than the thorax and has four sections, featuring a checkerboard pattern. Two

scales Scale or scales may refer to: Mathematics * Scale (descriptive set theory), an object defined on a set of points * Scale (ratio), the ratio of a linear dimension of a model to the corresponding dimension of the original * Scale factor, a number ...

are found at the base of edge of the species' wings, called epaulet and subepaulet. The epaulet is situated close to the thorax and usually black, while the subepaulet is located further out and white in color. The distinction of these scales is what separates it from other members of its family. Male ''S. barbata'' are on average smaller than the females and have stripes that are closer together. Below the section of the abdomen, males have the hypopygium, which is the genital segments. At the end of the genital segments is the anus, which is flanked by two curved forceps that lack lateral motion. The triangular accessory plate lies just outside of the forceps with the posterior and anterior claspers near the median of the plate. The two-jointed penis is located between the claspers next to the forceps. Males also possess combs on their hind legs composed of a close arrangement of short, blunt bristles. These combs are a distinctive feature of males.

Distribution and habitat

''Sarcophaga barbata'' can be found in

North American North America is a continent in the Northern and Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Caribbean Sea, and to the sou ...

and the

year round. These flies prefer areas with direct sunlight and warmer climates. ''S. barbata'' are usually found in dead and rotting meat and animal excrement, which are prime environments for them. This is because their larvae are facultative

parasites Parasitism is a close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The en ...

, as they feed on organic tissue and use the hosts' oxygen reserve. Such parasitic feeding causes dermal

myiasis Myiasis ( ), also known as flystrike or fly strike, is the parasitic infestation of the body of a live animal by fly larvae (maggots) that grow inside the host while feeding on its Biological tissue, tissue. Although flies are most commonly attr ...

in humans and animals.

Life cycle

The

life cycle Life cycle, life-cycle, or lifecycle may refer to: Science and academia *Biological life cycle, the sequence of life stages that an organism undergoes from conception to reproduction *Life-cycle hypothesis, in economics *Erikson's stages of psy ...

of ''S. barbata'' takes between 12 and 60 days. It involves the

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 ...

stage, the

pupa A pupa (; : pupae) is the life stage of some insects undergoing transformation between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in their life cycle, the stages th ...

stage, and the adult stage. The fly is

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 ...

, which means the female gives birth directly to live

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, the larvae, as opposed to giving birth to eggs that later form into larvae.

Embryo

The embryo develops inside the female body and is deposited through the

ovipositor The ovipositor is a tube-like organ used by some animals, especially insects, for the laying of eggs. In insects, an ovipositor consists of a maximum of three pairs of appendages. The details and morphology of the ovipositor vary, but typica ...

into the food source, which is usually decaying meat or animal excrement, with a still intact egg membrane. Some of the deposits might be unfertilized eggs and thus will degrade into the food source. The larvae will remain in their egg membranes until they are totally developed, at which point they will break out and begin to feed.

Larva

Fully developed larvae tend to be about 3.6 mm in length and of normal musocid shape. The smallest width is at the anterior end and tapers out reaching a stable cylindrical shape in the middle. The anal and genital areas are still not fully developed and are less prominent, but they have developed tubercles. The larvae contains irregularly spaced spines that form rings at the posterior and the anterior ends of each segment. The spine of the larvae becomes lighter closer to the posterior region while maintaining consistent color on both sides. The average female has 60 larvae, but can have as few as 6 larvae.

Pupa

The

puffs up as it develops over time. All cells of one region of the body aggregate and puff up together. However, there is no synchrony between regions of the body. The thoracic region puffs up one day before the abdominal region. This puffing pattern is related to the development of the

and is not hormonally controlled. After the pupa is fully developed and after

eclosion A pupa (; : pupae) is the life stage of some insects undergoing transformation between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in their life cycle, the stages th ...

has occurred, the

cuticle A cuticle (), or cuticula, is any of a variety of tough but flexible, non-mineral outer coverings of an organism, or parts of an organism, that provide protection. Various types of "cuticle" are non- homologous, differing in their origin, structu ...

of the newly emerged fly is darkened, which requires a hormonal cue that is delivered by the emergence.

Genetics

The

ovaries The ovary () is a gonad in the female reproductive system that produces ova; when released, an ovum travels through the fallopian tube/oviduct into the uterus. There is an ovary on the left and the right side of the body. The ovaries are endocr ...

of ''S. barbata'' experiences and under-replication of rDNA resulting in half the amount of rDNA as compared to the brain. A similar result is found in ''Drosophila hydei'', which displayed under-replication in both nurse and follicle cells. This degree of under-replication, 47%, is still less than that in polytene chromosomes of the salivary glands of ''

Drosophila melanogaster ''Drosophila melanogaster'' is a species of fly (an insect of the Order (biology), order Diptera) in the family Drosophilidae. The species is often referred to as the fruit fly or lesser fruit fly, or less commonly the "vinegar fly", "pomace fly" ...

'', which is 20%. This under-replication of rDNA is in stark contrast to the oocyte nuclei of most species of animals, which show an increase rRNA synthesis during the growth period. Under-replication is thought to be a product of asynchronous replication during mitosis. This made an important contribution to scientific research because it indicated a possible energy-saving mechanism employed by certain organisms during development, which is currently being studied.

Eye mutation

Wild type ''S. barbata'' possess a red eye color, but the

recessive In genetics, dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the effect of a different variant of the same gene on the other copy of the chromosome. The first variant is termed dominant and ...

autosomal An autosome is any chromosome that is not a sex chromosome. The members of an autosome pair in a diploid cell have the same morphology, unlike those in allosomal (sex chromosome) pairs, which may have different structures. The DNA in autosome ...

gene ''ivory'' causes a white eye color. The mutation blocks the formylkynurenine pathway, which produces xanthommatin. Xanthomattin is a yellow-brown pigment in its primary form, and its reduced form is red, which gives the flies their red eye color. These flies can display an intermediate eye color if they ingest xanthommatin precursors. ''Ivory''

gene mutation In biology, a mutation is an alteration in the nucleic acid sequence of the genome of an organism, virus, or extrachromosomal DNA. Viral genomes contain either DNA or RNA. Mutations result from errors during DNA or viral replication, mitosis ...

is homologous to the ''D. melanogaster'' mutation vermillion and the ''M. domestica'' mutation green. ''S. barbata'' with ivory are less viable than wild-type.

Spatial perception

An experiment to test the spatial perception of the larvae and its effect on pupation can be performed

in vitro ''In vitro'' (meaning ''in glass'', or ''in the glass'') Research, studies are performed with Cell (biology), cells or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in ...

. As the larvae are placed in the test tubes to explore the container thoroughly, they relate visual cues to

tactile Tactile may refer to: * Tactile, related to the sense of touch * Haptics (disambiguation) * Tactile (device), a text-to-braille translation device * Tactile paving See also * Tangibility, in law * Somatosensory system The somatosensory s ...

stimuli and distinguish between a closed and an open container. If the container is open, there is no delay in pupation and the pupa faces the open end. If the container is closed, it is delayed by four to five days only because the tactile stimuli is present. Pupation delay in response to a closed container stopped after the dimensions of the container increases beyond the limit of the larvae's spatial perception.

Relation to humans

Forensic importance

''Sarcophaga barbata'' is one of the dominant

necrophagous Necrophages are organisms that obtain nutrients by consuming decomposing dead animal biomass, such as the muscle and soft tissue of carrion, carcasses and cadaver, corpses (also known as carrion). The term derives from Greek , meaning 'dead', and ...

flesh fly species.

Forensic entomology Forensic entomology is a branch of applied entomology that uses insects and other arthropods as a basis for legal evidence. Insects may be found on cadavers or elsewhere around crime scenes in the interest of forensic science. Forensic entom ...

provides data about the interval of time that has passed

postmortem An autopsy (also referred to as post-mortem examination, obduction, necropsy, or autopsia cadaverum) is a surgical procedure that consists of a thorough examination of a corpse by dissection to determine the cause, mode, and manner of death; ...

and even circumstances surrounding the death. They are specifically useful since they deposit maggots directly onto the decomposing body, their larger, visible size, and difference in activity during different stages. Their main limitation, however, is due to lack of information surrounding their geographic distribution and taxonomic features.

Biological research

''Sarcophaga barbata'' was used to study the

of L-3-glycerophosphate in mitochondria. It is found that the L-3-glycerophosphate does not enter the

mitochondrial matrix In the mitochondrion, the matrix is the space within the inner membrane. It can also be referred as the mitochondrial fluid. The word "matrix" stems from the fact that this space is viscous, compared to the relatively aqueous cytoplasm. The mitoc ...

, unlike

pyruvate Pyruvic acid (CH3COCOOH) is the simplest of the alpha-keto acids, with a carboxylic acid and a ketone functional group. Pyruvate, the conjugate base, CH3COCOO−, is an intermediate in several metabolic pathways throughout the cell. Pyruvic ...

. This helps locate the L-3-glycerophosphate-flavoprotein oxidoreductase, which is on the inner membrane of the mitochondria.

References

{{Taxonbar, from=Q85799730 Sarcophagidae