Coelopa frigida

Coelopa frigida
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Diptera
Family:	Coelopidae
Genus:	Coelopa
Species:	C. frigida
Binomial name
	Coelopa frigida; (Fabricius, 1805)

Last updated August 14, 2023

Coelopa frigida is a species of seaweed fly or kelp fly. It is the most widely distributed species of seaweed fly.^[1] It can be found on most shorelines in the temperate Northern Hemisphere.^[1] Other species of seaweed flies include Coelopa nebularum and Coelopa pilipes .^[2]C. frigida feeds primarily on seaweed, and groups of C. frigida flies tend to populate near bodies of water. Climate change has led to an increase in C. frigida blooms along shores, which creates a pest problem for human beach-goers. C. frigida is also an important organism for the study of sexual selection, particularly female choice, which is influenced by genetics.

Description

C. frigida are the most common seaweed fly.^[3] They tend to aggregate on beaches with an abundance of stranded algae, but occasionally swarm inland.^[4] Their physical features include a dark brown to black body, a set of lighter colored legs, and large, translucent wings. Males are typically larger than females, though there is a wide range of adult sizes within the species.^[3]C. nebularum is currently suggested as a close cousin or even possible subspecies of C. frigida. This article therefore includes specifics regarding C. nebularum.^[4]

Distribution

C. frigida are commonly found on beaches with a relatively steady supply of stranded kelp, as the fly species is dependent on the decaying green and brown algae for both feeding and breeding. The geographic range, which is well documented, extends up the North Atlantic Coast into Iceland and encompasses the coasts of Russia, the North Sea, and Faroe Islands. Other regions reported to contain C. nebularum are found on the Pacific Coast of North America, the coast of Japan's Kuril Islands, and the eastern coasts of Russia.^[3]

Habitat

C. frigida need a constant supply of algae to feed and lay their eggs. Thus, coastal beaches with stranded seaweed are their preferred environment. The significant factors that determine the population density and spread are the age of algae, the presence or absence of high winds or storms, the rate of decay of algae, and temperature.^[5]

Influence of weather

Research shows that storms and their accompanying harsh weather conditions cause an overall decrease in the life expectancy of C. frigida.^[6]

Lower temperatures allow for beached seaweed to remain fresh for a longer period of time. Lower temperatures also force C. frigida to incubate in the egg stage to a greater extent before hatching. Meanwhile, higher temperatures cause an acceleration in the decomposition of algae and also increases the rate of egg development. There has been no significant research done on differentiating the average lifetimes of C. frigida exposed to different temperatures.^[6]

Taxonomy

The first documented discovery of C. frigida was in 1805 by Fabricius. He called the fly frigida, meaning "cold", presumably from his comment "Habitat in Norwagiae Lapponis frigoris summi patiens," meaning "It lives in Norwegian Lapland, tolerating extreme cold."^[7] Throughout history, there have been many additions and changes suggested. Haliday discovered different sizes of C. frigida on the coast of Ireland and gave them the names: C. gravis, C. simplex, and C parvula. Stenhammer similarly found the species on the coast of Scandinavia, and dubbed them C. nitidula and C. eximia. Only after Aldrich and Hennig's revision of the entire Palearctic fauna of Coelopa did the current standing of nomenclature come to light. Currently, C. frigida is the official name for this species of fly. There is an ongoing dispute on whether C. nebularum should be considered a subspecies of C. frigida or recently speciated species of Coelopa.^[4]

Life history

Egg

C. frigida's egg phase is on average 12.25 ± 1.05 days, but changes depending on the presence of alcohol dehydrogenase or higher temperatures. Higher temperatures, such as those caused by climate change, may cause eggs to hatch more quickly. The eggs are laid en masse in the leaves of stranded algae.^[5]

Adult

The adults emerge from their pupal shells ready to fly in search of mates. Their wings are typically 6 mm and once dry carry them around their current seaweed plot or to other stranded algae. Their bodies are colored a light brown to black, with a few yellow specks. Lastly, their legs are much longer than before eclosion and have hooked attachments at the end to better grip onto seaweed.^[3]^[4]

The fly oviposits in dead kelp that washes up on beaches.^[8] This is the only place it lays eggs, and it can do so on many species of kelp and seaweed,^[9] including species of Laminaria and Fucus .^[10] A female fly lays up to five clutches of 80 eggs each.^[11] The larvae feed upon the bacteria coating the dead kelp.^[9] The life cycle is about 30 days long.^[1]^[11]

Food resources

The main food source for C. frigida is seaweed that has washed up onto the beaches. The adults detect the scent of the seaweed and lie their eggs in the decaying algae. The seaweed's particular environment allows the eggs to hatch, and the larvae begin to burrow into the seaweed. The brown and green algae preferred by C. frigida are usually of either the genus Lamniaria or the genus Fucus . There is still research being done on whether it is the seaweed itself, the microorganisms within it, or a combination of the two that provides the nutrition needed by the C. frigida larvae. The algae also provides a safe habitat to live in and a perfect moist environment for eggs, which prevents desiccation. Most adults stay in the seaweed patch of their birth until it returns to the ocean, at which point the adults fly in search of alternative algae bunches to feed, live, and mate on.^[4]

Morphology

There are four defining characteristics of C. frigida. The first is the size of the body, which ranges from 5 mm to 6 mm. The size of the body depends on the specific alpha or beta alleles associated with chromosomal inversion. The alpha genes causes individuals to grow to a larger size with a "peacock's tail". However, these larger individual typically spend 2-4 more days throughout the development process before becoming adults. The bodies range from a dark brown to black. The second is color of the legs. The legs of C. frigida are mostly all the same size, with the only difference being in color. The hue of the legs range from a light brown, to yellow, to black. The third and fourth features are their tergite and accompanying bristles. Most individuals of C. frigida have 6 tergites. Their size may differ according to how far along each individual is in their adult life. The color of their tergites is generally dark brown. Lastly, the accompanying bristles on the tergites vary in different lengths. Most are proportional to the overall body or tergite size. The color of such setae are either black or the color of the attached tergite.^[4]

Ecological Adaptations

C. frigida are highly waterproof due to the a collection of hairs that cover their entire exoskeleton. They can easily escape from algae/seaweed beds that are pulled back into the ocean by simply bobbing up to the surface and then flying back to the coast. This waterproofing has been tested by placing adults into a bottle of seawater and shaking vigorously, with the only result observed being still-dry flies emerging from the water.

Mating

Mating behavior in C. frigida is dictated by larger males attempting to copulate with smaller females. Larger males have an increased mating success rate than their smaller counterparts. Thus, sexual selection tends to favor males that are larger or can latch on to females more tightly. This sexual selection for larger males is countered by natural selection for smaller males. Smaller males have a lower incubation time, and thus are more likely to survive past their developmental age to adulthood. C. frigida are polygynous, with females devoting the majority of resources to laying eggs to increase their reproductive success. Meanwhile, the males choose to mate with as many receptive females as possible to increase their reproductive success.^[3]

Laboratory studies

This fly is sometimes cultured in the laboratory.^[11] Its behavior is studied in an effort to understand sexual selection, especially female choice.^[12] Studies suggest that female flies of this species prefer larger males to smaller.^[3]^[13]

The species engages in lekking and sexual conflict.^[14] Females perform rejection behaviors when mounted by males, and may mate with larger males because larger males are more able to force the mating.^[14] As females are more likely to successfully reject smaller males, sexual selection favors larger ones.^[14] Mating behaviors are genetically influenced, as evidenced by a preference for smaller males among females of a certain genotype.^[15]

Genetic research

There are two main focuses of genetic research on C. frigida. The first aspect is the differentiation of C. frigida from similar looking flies and C. nebularum. The second focus is on the chromosomal inversion of certain alleles to produce flies of differing sizes, and natural selection on certain sizes.

The initial discovery of C. frigida was confused due to their variance in size. This dispute was mostly cleared by delving past their physical characteristics into their genetics, in which most of the seaweed flies were found to belong to C. frigida. The only majorly differing genetic line was associated with C. nebularum. C. Nebularum had only recently speciated from C. frigida due to geographic differences, thus it is still widely debated if they belong in the same species or if they're close cousins.^[4]

The chromosomal inversion of the alpha or beta allele in C. frigida produces a distinct difference in adult size. Individuals homozygous for the alpha allele are physically larger and more developed. They benefit from the physicality with increased longevity and increased fecundity. However, these individuals have 2–4 days more in their developmental phases to grow to such an extent. These may be precious days that the seaweed bed is washed back into the ocean, killing the C. frigida. On the other hand, individuals homozygous for the beta allele are physically smaller. They benefit by growing into their adult phase faster, but have more trouble finding receptive mates.^[3]^[5]

Enemies

C. frigida competes with another seaweed fly, C. pilipes, for resources.^[10] One might think that the number one predator of C. frigida would be birds such as sandpipers. Seabirds (including the purple sandpiper, Calidris maritima) do eat adult flies; however, these birds only peck within the first few inches of the seaweed and don't penetrate deep enough to get to the eggs and larvae.^[16] On the other hand, insects from the Coleoptera and Hymenoptera order have been found to eat C. frigida eggs and larvae in laboratory conditions. More research needs to be done to conclude their presence in the seaweed and their feeding habits.

C. frigida is also host to the mite Thinoseius fucicola .^[2]

Human interaction

Typically, the leks that C. frigida form stay within their optimal environment of seaweed patches. However, due to increasing temperatures and more frequent storms resulting from climate change, more algae is washed ashore and accompanying it is an increase in the population density of C. frigida. "Blooms" of the flies can occur, possibly when temperatures and amounts of kelp increase.^[8] These aggregations are known to pester and annoy beachgoers, but may also be blown inland to city dwellers.^[4]

Related Research Articles

Disassortative mating is a mating pattern in which individuals with dissimilar phenotypes mate with one another more frequently than would be expected under random mating. Disassortative mating reduces the mean genetic similarities within the population and produces a greater number of heterozygotes. The pattern is character specific, but does not affect allele frequencies. This nonrandom mating pattern will result in deviation from the Hardy-Weinberg principle.

Fucus is a genus of brown algae found in the intertidal zones of rocky seashores almost throughout the world.

Laminaria is a genus of brown seaweed in the order Laminariales (kelp), comprising 31 species native to the north Atlantic and northern Pacific Oceans. This economically important genus is characterized by long, leathery laminae and relatively large size. Some species are called Devil's apron, due to their shape, or sea colander, due to the perforations present on the lamina. Others are referred to as tangle. Laminaria form a habitat for many fish and invertebrates.

<span class="mw-page-title-main">Stalk-eyed fly</span> Family of dipteran insects with antennae located on eyestalks

Stalk-eyed flies are insects of the fly family Diopsidae. The family is distinguished from most other flies by most members of the family possessing "eyestalks": projections from the sides of the head with the eyes at the end. Some fly species from other families such as Drosophilidae, Platystomatidae, Richardiidae, and Tephritidae have similar heads, but the unique character of the Diopsidae is that their antennae are located on the stalk, rather than in the middle of the head as in all other flies. Stalked eyes are present in all members of the subfamily Diopsinae, but are absent in the Centrioncinae, which retain unstalked eyes similar to those of other flies. The stalked eyes are usually sexually dimorphic, with eyestalks present but shorter in females.

Nephila pilipes is a species of golden orb-web spider. It resides all over countries in East and Southeast Asia as well as Oceania. It is commonly found in primary and secondary forests and gardens. Females are large and grow to a body size of 30–50 mm, with males growing to 5–6 mm. It is the second largest of the orb-weaving spiders apart from the recently discovered Nephila komaci. The first, second, and fourth pairs of legs of juvenile females have dense hairy brushes, but these brushes disappear as the spider matures.

<span class="mw-page-title-main">Sexual conflict</span> Term in evolutionary biology

Sexual conflict or sexual antagonism occurs when the two sexes have conflicting optimal fitness strategies concerning reproduction, particularly over the mode and frequency of mating, potentially leading to an evolutionary arms race between males and females. In one example, males may benefit from multiple matings, while multiple matings may harm or endanger females, due to the anatomical differences of that species. Sexual conflict underlies the evolutionary distinction between male and female.

The Coelopidae or kelp flies are a family of Acalyptratae flies, they are sometimes also called seaweed flies, though both terms are used for a number of seashore Diptera. Fewer than 40 species occur worldwide. The family is found in temperate areas, with species occurring in the southern Afrotropical, Holarctic, and Australasian regions.

Phormia regina, the black blow fly, belongs to the blow fly family Calliphoridae and was first described by Johann Wilhelm Meigen.

Scathophaga stercoraria, commonly known as the yellow dung fly or the golden dung fly, is one of the most familiar and abundant flies in many parts of the Northern Hemisphere. As its common name suggests, it is often found on the feces of large mammals, such as horses, cattle, sheep, deer, and wild boar, where it goes to breed. The distribution of S. stercoraria is likely influenced by human agriculture, especially in northern Europe and North America. The Scathophaga are integral in the animal kingdom due to their role in the natural decomposition of dung in fields. They are also very important in the scientific world due to their short life cycles and susceptibility to experimental manipulations; thus, they have contributed significant knowledge about animal behavior.

Anastrepha ludens, the Mexican fruit fly or Mexfly, is a species of fly of the Anastrepha genus in the Tephritidae family. It is closely related to the Caribbean fruit fly Anastrepha suspensa, and the papaya fruit fly Anastrepha curvicauda.

Interlocus sexual conflict is a type of sexual conflict that occurs through the interaction of a set of antagonistic alleles at two or more different loci, or the location of a gene on a chromosome, in males and females, resulting in the deviation of either or both sexes from the fitness optima for the traits. A co-evolutionary arms race is established between the sexes in which either sex evolves a set of antagonistic adaptations that is detrimental to the fitness of the other sex. The potential for reproductive success in one organism is strengthened while the fitness of the opposite sex is weakened. Interlocus sexual conflict can arise due to aspects of male–female interactions such as mating frequency, fertilization, relative parental effort, female remating behavior, and female reproductive rate.

Sepsis cynipsea is a European species of fly and member of the family Sepsidae. It is a coprophagous fly that feeds on dung. These flies are most commonly found around freshly laid cattle dung where they eat and reproduce. Due to human agricultural practices involving cows, these flies are now common in other areas of the world.

<span class="mw-page-title-main">Sexual selection in insects</span>

Sexual selection in insects is about how sexual selection functions in insects. The males of some species have evolved exaggerated adornments and mechanisms for self-defense. These traits play a role in increasing male reproductive expectations by triggering male-male competition or influencing the female mate choice, and can be thought of as functioning on three different levels: individuals, colonies, and populations within an area.

Kelp fly is one common name of species of flies in a number of families of "true flies" or Diptera. They generally feed on stranded and rotting seaweed, particularly kelp in the wrack zone. When conditions are suitable they are very numerous and may be ecologically important in the turnover of organic material on the coast. In this role they also may be an important item in the diet of beach-dwelling animals and birds. The flies most generally referred to as kelp flies are the widely distributed Coelopidae, such as Coelopa pilipes. In popular speech however, they are not clearly distinguished from other flies with similar feeding habits, such as the Heterocheilidae, the Helcomyzinae and sundry members of the Anthomyiidae.

Chaetocoelopa littoralis, commonly known as the hairy kelp fly, is a fly of the family Coelopidae. It is endemic to New Zealand and is widely distributed around the coastline, including offshore islands. These flies are black in appearance and show large variation in size, with males tending to be larger and more robust and 'hairy' than females.

Coelopa is a genus of kelp flies in the family Coelopidae. There are about 14 described species in Coelopa.

Drosophila silvestris is a large species of fly in the family Drosophilidae that are primarily black with yellow spots. As a rare species of fruit fly endemic to Hawaii, the fly often experiences reproductive isolation. Despite barriers in nature, D. silvestris is able to breed with D. heteroneura to create hybrid flies in the laboratory.

Sepsis thoracica, more commonly known as the black scavenger fly, a species of fly from the genus Sepsis and the family Sepsidae. It was discovered by Robineau-Desvoidy in 1830. It resembles a small flying ant. The fly is most commonly found inhabiting cow dung.

Coelopa pilipes is a common European species of kelp fly. It was described by A. H. Haliday in 1838. Their appearance differs greatly from that of other Coelopa flies.

Teleopsis dalmanni, synonym Cyrtodiopsis dalmanni, also known as the Malaysian stalk-eyed fly, is a species of fly in the family Diopsidae. T. dalmanni flies possess lateral elongations on their head capsules called eyestalks. These eyestalks play an important role in mate selection and as a result physical characteristic of the fly has been the subject of several studies on sexual selection, natural selection, and mating behavior.

References

1 2 3 "Kelp Fly". Marine Wildlife Encyclopedia. Oceana. Archived from the original on 24 July 2011.
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1 2 3 4 5 6 7 8 Laamanen, T. R.; Petersen, F. T.; Meier, R. (April 2003). "Kelp flies and species concepts - the case of Coelopa frigida (Fabricius, 1805) and C. nebularum Aldrich, 1929 (Diptera: Coelopidae)". Journal of Zoological Systematics and Evolutionary Research. 41 (2): 127–136. doi:10.1046/j.1439-0469.2003.00209.x. ISSN 0947-5745.
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1 2 Butlin, R.K.; Day, T.H. (April 1989). "Environmental correlates of inversion frequencies in natural populations of seaweed flies (Coelopa frigida)". Heredity. 62 (2): 223–232. doi: 10.1038/hdy.1989.32 .
↑ Fabricius, Johan Christian (1805). Systema Antiliatorum. Braunschweig: Carolus Reichard. p. 307.
1 2 Mather, Kate (June 18, 2011). "South Bay beaches hit by swarms of kelp flies". Los Angeles Times . Retrieved June 18, 2011.
1 2 Cullen, Sally J.; Young, Alison M.; Day, Thomas H. (1987). "Dietary requirements of seaweed flies (Coelopa frigida)". Estuarine, Coastal and Shelf Science . 24 (5): 701. Bibcode:1987ECSS...24..701C. doi:10.1016/0272-7714(87)90108-9.
1 2 Edward, Dominic A.; Newton, Jason; Gilburn, André S. (2008). "Investigating dietary preferences in two competing dipterans, Coelopa frigida and Coelopa pilipes, using stable isotope ratios of carbon and nitrogen". Entomologia Experimentalis et Applicata. 127 (3): 169. doi:10.1111/j.1570-7458.2008.00692.x. S2CID 83750841.
1 2 3 Burnet, B.; Thompson, U. (2009). "Laboratory culture of Coelopa frigida (Fabricius) (Diptera: Coelopidae)". Proceedings of the Royal Entomological Society of London A. 35 (4–6): 85. doi:10.1111/j.1365-3032.1960.tb00672.x.
↑ MacDonald, C.; Brookfield, J. F. Y. (2002). "Intraspecific molecular variation in the seaweed fly Coelopa frigida consistent with behavioural distinctness of British and Swedish populations". Molecular Ecology. 11 (9): 1637–46. doi:10.1046/j.1365-294X.2002.01559.x. PMID 12207715. S2CID 7080798.
↑ Gilburn, A. S.; Day, T. H. (1994). "Sexual dimorphism, sexual selection and the formula chromosomal inversion polymorphism in the seaweed fly, Coelopa frigida". Proceedings of the Royal Society B: Biological Sciences. 257 (1350): 303. doi:10.1098/rspb.1994.0130. S2CID 86383748.
1 2 3 Shuker, D. M. (2002). "Mate sampling and the sexual conflict over mating in seaweed flies". Behavioral Ecology. 13: 83–86. doi: 10.1093/beheco/13.1.83 .
↑ Blyth, Jennifer E.; Gilburn, Andre S. (2011). "The function of female behaviours adopted during premating struggles in the seaweed fly, Coelopa frigida". Animal Behaviour. 81: 77–82. doi:10.1016/j.anbehav.2010.09.013. S2CID 53190603.
↑ Summers, R. W.; Smith, S.; Nicoll, M.; Atkinson, N. K. (1990). "Tidal and sexual differences in the diet of Purple Sandpipers Calidris maritima in Scotland". Bird Study. 37 (3): 187–94. doi: 10.1080/00063659009477056 .