''Chaoborus'' is a genus of
midge
A midge is any small fly, including species in several families of non-mosquito Nematoceran Diptera. Midges are found (seasonally or otherwise) on practically every land area outside permanently arid deserts and the frigid zones. Some mid ...
s in the family
Chaoboridae
Chaoboridae, commonly known as phantom midges or glassworms, is a family of fairly common midges with a cosmopolitan distribution. They are closely related to the Corethrellidae and Chironomidae; the adults are differentiated through peculiarit ...
. The
larva
A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle.
The ...
e are known as glassworms because they are
transparent. They can be found commonly in
lake
A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much large ...
s all over the world and can be up to . The adults are sometimes called phantom midges or lake flies.
Appearance
Glassworms are almost entirely transparent, except for pairs of black kidney-shaped structures in the front and the back of the body. These dots are the air sacs. They use these air sacs to migrate up and down in lakes. Glassworms breathe through the end of their
abdomen
The abdomen (colloquially called the belly, tummy, midriff, tucky or stomach) is the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the front part of the abdominal segment of the torso. ...
and have two small
eye
Eyes are organs of the visual system. They provide living organisms with vision, the ability to receive and process visual detail, as well as enabling several photo response functions that are independent of vision. Eyes detect light and conv ...
s at the front of their bodies.
Behavior
''Chaoborus'' adults do not bite mammals or suck
blood
Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood in the c ...
. Larvae live in open waters and even sediments, where there may be little
oxygen
Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as wel ...
for them to breathe. In some lakes they can be found as deep as . In these deep
anoxic waters they can avoid predation more easily than near the surface. They get around the fact that a normal air filled
invertebrate trachea
The trachea, also known as the windpipe, is a cartilaginous tube that connects the larynx to the bronchi of the lungs, allowing the passage of air, and so is present in almost all air-breathing animals with lungs. The trachea extends from the la ...
l system would fail at these depths by having it reduced to just two air sacs. They are predaceous, and catch their prey with their modified
prehensile
Prehensility is the quality of an appendage or organ (anatomy), organ that has Adaptation (biology), adapted for grasping or holding. The word is derived from the Latin term ''prehendere'', meaning "to grasp". The ability to grasp is likely der ...
antennae. They look somewhat like
mosquito larvae, on which they
prey
Predation is a biological interaction where 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 the ...
and frequently destroy in large numbers. ''Chaoborus'' are considered opportunistic eaters, as their main diet consists of
copepods
Copepods (; meaning "oar-feet") are a group of small crustaceans found in nearly every freshwater and saltwater habitat. Some species are planktonic (inhabiting sea waters), some are benthic (living on the ocean floor), a number of species have p ...
and
cladocerans
The Diplostraca or Cladocera, commonly known as water fleas, are a superorder of small crustaceans that feed on microscopic chunks of organic matter (excluding some predatory forms).
Over 1000 species have been recognised so far, with many more ...
, though they are believed to prefer copepods. However, they tend to select whatever prey enters its strike zone as it is not known for chasing prey. Prey selection also varies between species as head and mandible size dictate maximum prey size.
![Lake flies, Lake Malawi (2499202894)](https://upload.wikimedia.org/wikipedia/commons/e/e7/Lake_flies%2C_Lake_Malawi_%282499202894%29.jpg)
Their main predator is fish, which can cause a behavioral response due to light factors influenced by their presence. This fish factor causes an increase in the average depth the individuals can be found. This vertical migration behavior is believed to be a chemical reaction, rather than a visual or mechanical. In the
African Great Lakes of
Malawi
Malawi (; or aláwi Tumbuka: ''Malaŵi''), officially the Republic of Malawi, is a landlocked country in Southeastern Africa that was formerly known as Nyasaland. It is bordered by Zambia to the west, Tanzania to the north and northeast ...
and
Victoria (but not
Tanganyika
Tanganyika may refer to:
Places
* Tanganyika Territory (1916–1961), a former British territory which preceded the sovereign state
* Tanganyika (1961–1964), a sovereign state, comprising the mainland part of present-day Tanzania
* Tanzania Main ...
where this genus is absent, perhaps because of chemical factors), huge swarms of ''Chaoborus'' midges occur and are collected by local people to make
''kungu'' cakes, biscuits or burgers, a local delicacy rich in
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...
.
[Morris, B. (2004). Insects and Human Life, pp. 73—76. ][van Huis, A.; H. van Gurp; and M. Dicke (2012). The Insect Cookbook: Food for a Sustainable Planet, p. 31. ] David Livingstone
David Livingstone (; 19 March 1813 – 1 May 1873) was a Scottish physician, Congregationalist, and pioneer Christian missionary with the London Missionary Society, an explorer in Africa, and one of the most popular British heroes of t ...
(1865) claimed that they "tasted not unlike caviare".
[
]
Life cycle
''Chaoborus'' spends the majority of its life in the larval stage. In this larval stage, there are 4 growth instars before reaching adulthood. Most ''Chaoborus'' species are univoltine, or live for only one year, though some populations have been recorded as having a two-year generation time. Timing of pupation depends on local environmental conditions, though generally occurs after any ice has thawed and temperatures in the water begin to rise again.
Collection
The simplest way to collect glassworms is by a plankton net
A plankton net is equipment used for collecting samples of plankton in standing bodies of water. It consists of a towing line and bridles, nylon mesh net, and a cod end. Plankton nets are considered one of the oldest, simplest and least expensi ...
. They can be found in almost all water, but most abound in fish-free quarry ponds during winter. Glassworms are very easy to store if the water is kept cold and aerated. They are very tolerant to bad water conditions, including chlorine
Chlorine is a chemical element with the Symbol (chemistry), symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate betwee ...
. They are sometimes collected and sold as fish food
Aquarium fish feed is plant or animal material intended for consumption by pet fish kept in aquariums or ponds. Fish foods normally contain macronutrients, trace elements and vitamins necessary to keep captive fish in good health. Approximately ...
.
Species
These 44 species belong to the genus ''Chaoborus'':
* ''Chaoborus albatus
''Chaoborus albatus'' is a species of phantom midges in the family Chaoboridae
Chaoboridae, commonly known as phantom midges or glassworms, is a family of fairly common midges with a cosmopolitan distribution. They are closely related to the ...
'' Johnson, 1921 i g b
* ''Chaoborus americanus
''Chaoborus'' is a genus of midges in the family Chaoboridae. The larvae are known as glassworms because they are transparency (optics), transparent. They can be found commonly in lakes all over the world and can be up to . The adults are sometim ...
'' (Johannsen, 1903) i c g
* '' Chaoborus annandalei'' Edwards, 1930 c g
* '' Chaoborus anomalus'' Edwards, 1930 c g
* '' Chaoborus antillum'' Knab, 1913 c g
* '' Chaoborus asiaticus'' (Giles, 1901) c g
* '' Chaoborus astictopus'' Dyar & Shannon, 1924 i c g b (clear lake gnat)
* '' Chaoborus australis'' Sahnnon & Ponte, 1928 c g
* '' Chaoborus bolviensis'' Lane & Heredia, 1956 c g
* '' Chaoborus brasiliensis'' (Theobald, 1901) c g
* '' Chaoborus brevisector'' Edwards, 1930 c g
* '' Chaoborus ceratopogones'' (Theobald, 1903) c g
* '' Chaoborus cooki'' Saether, 1970 i c g b
* '' Chaoborus cornfordii'' (Theobald, 1903) c g
* '' Chaoborus crystallinus'' (De Geer, 1776) i c g
* '' Chaoborus depereti'' Meunier, 1915 c g
* ''Chaoborus edulis
''Chaoborus edulis'' is a species of phantom midges (flies in the family Chaoboridae). Colloquially, the larval stage is termed a glassworm
''Chaoborus'' is a genus of midges in the family Chaoboridae. The larvae are known as glassworms becaus ...
'' Edwards, 1930 c g
* '' Chaoborus elnorae'' Shannon & Ponte, 1928 c g
* '' Chaoborus festivus'' Dyar & Shannon, 1924 i c g b
* ''Chaoborus flavicans
''Chaoborus flavicans'' is a species of fly in the family Chaoboridae. It is found in the Palearctic
The Palearctic or Palaearctic is the largest of the eight biogeographic realms of the Earth. It stretches across all of Eurasia north of th ...
'' (Meigen, 1830) i c g b
* '' Chaoborus flavidulus'' Edwards, 1930 c g
* '' Chaoborus freemani'' Verbeke, 1958 c g
* ''Chaoborus fryeri
''Chaoborus'' is a genus of midges in the family Chaoboridae. The larvae are known as glassworms because they are transparent. They can be found commonly in lakes all over the world and can be up to . The adults are sometimes called phantom midg ...
'' Verbeke, 1958 c g
* ''Chaoborus fuscinervis
''Chaoborus'' is a genus of midges in the family Chaoboridae. The larvae are known as glassworms because they are transparent. They can be found commonly in lakes all over the world and can be up to . The adults are sometimes called phantom midg ...
'' Edwards, 1930 c g
* ''Chaoborus indicus
''Chaoborus'' is a genus of midges in the family Chaoboridae. The larvae are known as glassworms because they are transparent. They can be found commonly in lakes all over the world and can be up to . The adults are sometimes called phantom midg ...
'' (Giles, 1904) c g
* ''Chaoborus longicercus
''Chaoborus'' is a genus of midges in the family Chaoboridae. The larvae are known as glassworms because they are transparent. They can be found commonly in lakes all over the world and can be up to . The adults are sometimes called phantom midg ...
'' Colless, 1986 c g
* ''Chaoborus maculipes
''Chaoborus maculipes'' is a species of phantom midges (flies in the family Chaoboridae
Chaoboridae, commonly known as phantom midges or glassworms, is a family of fairly common midges with a cosmopolitan distribution. They are closely related ...
'' Stone, 1965 i c g b
* ''Chaoborus magnificus
''Chaoborus'' is a genus of midges in the family Chaoboridae. The larvae are known as glassworms because they are transparent. They can be found commonly in lakes all over the world and can be up to . The adults are sometimes called phantom midg ...
'' Lane, 1942 c g
* ''Chaoborus manilensis
''Chaoborus'' is a genus of midges in the family Chaoboridae. The larvae are known as glassworms because they are transparent. They can be found commonly in lakes all over the world and can be up to . The adults are sometimes called phantom midg ...
'' (Schiner, 1868) c g
* ''Chaoborus microstictus
''Chaoborus'' is a genus of midges in the family Chaoboridae. The larvae are known as glassworms because they are transparent. They can be found commonly in lakes all over the world and can be up to . The adults are sometimes called phantom midg ...
'' Edwards, 1930 c g
* ''Chaoborus nyblaei
''Chaoborus'' is a genus of midges in the family Chaoboridae. The larvae are known as glassworms because they are transparent. They can be found commonly in lakes all over the world and can be up to . The adults are sometimes called phantom midg ...
'' (Zetterstedt, 1838) c g
* ''Chaoborus obscuripes
''Chaoborus'' is a genus of midges in the family Chaoboridae. The larvae are known as glassworms because they are transparent. They can be found commonly in lakes all over the world and can be up to . The adults are sometimes called phantom midg ...
'' (Wulp, 1859) i c g
* ''Chaoborus ornatipennis
''Chaoborus'' is a genus of midges in the family Chaoboridae. The larvae are known as glassworms because they are transparent. They can be found commonly in lakes all over the world and can be up to . The adults are sometimes called phantom midg ...
'' Colless, 1986 c g
* ''Chaoborus pallidipes
''Chaoborus'' is a genus of midges in the family Chaoboridae. The larvae are known as glassworms because they are transparent. They can be found commonly in lakes all over the world and can be up to . The adults are sometimes called phantom midg ...
'' (Theobald, 1911) c g
* ''Chaoborus pallidus
''Chaoborus'' is a genus of midges in the family Chaoboridae. The larvae are known as glassworms because they are transparent. They can be found commonly in lakes all over the world and can be up to . The adults are sometimes called phantom midg ...
'' (Fabricius, 1781) c g
* ''Chaoborus punctilliger
''Chaoborus'' is a genus of midges in the family Chaoboridae. The larvae are known as glassworms because they are transparent. They can be found commonly in lakes all over the world and can be up to . The adults are sometimes called phantom midg ...
'' Colless, 1986 c g
* ''Chaoborus punctipennis
''Chaoborus punctipennis'' is a species of phantom midges (flies in the family Chaoboridae
Chaoboridae, commonly known as phantom midges or glassworms, is a family of fairly common midges with a cosmopolitan distribution. They are closely rela ...
'' (Say, 1823) i c g b
* ''Chaoborus queenslandensis
''Chaoborus'' is a genus of midges in the family Chaoboridae. The larvae are known as glassworms because they are transparent. They can be found commonly in lakes all over the world and can be up to . The adults are sometimes called phantom midg ...
'' (Theobald, 1905) c g
* ''Chaoborus sampsera
''Chaoborus'' is a genus of midges in the family Chaoboridae. The larvae are known as glassworms because they are transparent. They can be found commonly in lakes all over the world and can be up to . The adults are sometimes called phantom midg ...
'' Ogawa & Judd, 2008 c g
* ''Chaoborus souzai
''Chaoborus'' is a genus of midges in the family Chaoboridae. The larvae are known as glassworms because they are transparent. They can be found commonly in lakes all over the world and can be up to . The adults are sometimes called phantom midg ...
'' Lane, 1939 c g
* ''Chaoborus stonei
''Chaoborus'' is a genus of midges in the family Chaoboridae. The larvae are known as glassworms because they are transparent. They can be found commonly in lakes all over the world and can be up to . The adults are sometimes called phantom midg ...
'' Lane, 1942 c g
* ''Chaoborus trivittatus
''Chaoborus trivittatus'' is a species of phantom midges (flies in the family Chaoboridae
Chaoboridae, commonly known as phantom midges or glassworms, is a family of fairly common midges with a cosmopolitan distribution. They are closely relat ...
'' (Loew, 1862) i c g b
* ''Chaoborus unicolor
''Chaoborus'' is a genus of midges in the family Chaoboridae. The larvae are known as glassworms because they are transparent. They can be found commonly in lakes all over the world and can be up to . The adults are sometimes called phantom midg ...
'' Lane, 1942 c g
* ''Chaoborus vagus
''Chaoborus'' is a genus of midges in the family Chaoboridae. The larvae are known as glassworms because they are transparent. They can be found commonly in lakes all over the world and can be up to . The adults are sometimes called phantom midg ...
'' Colless, 1986 c g
Data sources: i = ITIS,[ c = Catalogue of Life,][ g = GBIF,][ b = Bugguide.net]
References
{{Taxonbar, from=Q2707905
Culicoidea genera
Chaoboridae