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Subclass: Branchiura Thorell, 1864 = Carp Lice, Carp Eaters


A subclass of Carpoyeds - Branchiura - are crustaceans that parasitize on freshwater fish. Often on the surface of their bodies, especially where the skin is thinner and not so strong currents of water washing the fish, that is, gill covers and pectoral fins, you can find very flat crustaceans 0.5-30 mm long, attached to the skin of the fish with suction cups and eagerly sucking all the blood. Unlike copepods, they cannot be considered permanent parasites, as When saturated, carpoeids leave the fish and swim at a great speed.

Carp-eaters live not only in fresh waters, but also in the sea. In total, approximately 130 species of carboedoids are known. In structure, these crustaceans differ quite sharply from copepods. Their flat body is clearly divided into two sections - front and back. The anterior part is covered from above with a wide shield - a carapace, on the dorsal surface of which there is a pair of large faceted eyes, and between them 1-3 simple pauplial eyes. Partially, this shield also covers the anterior of the four free thoracic segments belonging to the posterior part of the body, each equipped with a pair of bifurcated swimming legs. The body ends with a shortened abdominal region, merged with wide furcal branches. The appendages of the anterior section are adapted to parasitic existence, and the appendages of the posterior section are adapted to swimming. Both pairs of antennas are very short. The mandibles form a proboscis directed backwards, introduced into the integument of the fish and used to suck their blood. An acute type departs from it, also helping the crustacean to stay on the skin of the fish. Powerful suckers are located on the sides of the proboscis, which are very strongly changed front jaws. The back jaws are single-branched and serve for attachment to the host. Four pairs of pectoral legs carry numerous cirrus bristles and make strong swings, thanks to which the crustacean can quickly swim with its back side up. The intestines of carpoeids are as adapted to parasitic existence as their oral appendages. Its middle section is equipped with branched blind outgrowths that serve as reservoirs for sucked blood.

Due to the ability to store food for future use, carbohydrates can not eat for up to 3 weeks, gradually consuming their supplies. When a crustacean attacks a fish, vision does not play any role. Crustaceans are guided mainly by the movement of water and partly by the chemical sense.

They perceive corresponding irritations with numerous sensitive setae located on different parts of the body. If you lower the filter paper into the aquarium with carpoids and move it in the water, the crustaceans rush onto the paper, but, touching it, sail away. If a fish is pre-wiped with a piece of paper, carpoeids stay on it a little longer. Carpo-eaters chase the fish, quickly moving in the same direction parallel to it, and then sit on the victim's head. Subsequently, they crawl onto those parts of the body of the fish that are least washed by water and where the covers are relatively thin, that is, they are attached mainly behind the gill covers and pectoral fins. Having clung to the fish, the crustaceans continue to act with swimming legs, exciting the current of water necessary for breathing. It is carried out through thin-walled sections of carapace. Carpoeids do not have a heart; blood in the body cavity moves due to contractions of the intestines and muscles of the abdominal region.

Carpoids have no preference for certain types of fish. Moreover, they can attack other aquatic vertebrates - newts and frog tadpoles. Some marine species of carnivores parasitize cephalopods, such as Argulus arcussonensis on cuttlefish. The male impregnates the female attached to the fish, holding her rear pectoral legs with her own and slipping her abdominal section under it so that the openings of its vas deferens coincide with the openings of her oviducts. Sperm enters directly into the female genital tract. Before laying eggs, the female leaves the fish and swims in search of underwater plants, stones, or another suitable substrate. She lays a double row of eggs (ordinary Argulus foliaceus from 20 to 250 eggs) on this substrate, attaching them with a special secret. Typically, faces are not swept out immediately, but intermittently, during which the female again attacks the fish and sucks their blood. In this regard, carboedoids differ from most other crustaceans whose females carry eggs on themselves in egg bags or in a specially brood bag. After 3-5 weeks, young but not yet fully formed crustaceans emerge from the eggs of Argulus foliaceus. They have long rear antennas with which they swim, their mandibles are equipped with palps, the front jaws are not yet turned into suckers, the swimming legs are underdeveloped, and the carapace is shortened. Larvae attach to fish using front antennas and end spikes of the front jaws. During the first 8 days of staying on fish, the crustacean molt twice, and its rear antennas and mandibles are shortened, but swimming legs fully develop. After the third molt, suction cups begin to form due to the front jaws; this process only accumulates after the fifth molt. So, gradually, as a result of molts occurring every 3-4 days, an adult crustacean is formed. In a number of species, the development is even more reduced: a fully formed, but still not fully matured individual leaves the egg, and there are species with a longer development when a nauplius hatches from the egg.

Carp beetles are quite widespread both in fresh waters and in the seas and can be considered very common fish parasites, including economically valuable ones. However, the harm they bring to the fish is small. In very rare cases, they cause the death of fish, and even then only young ones. Many researchers consider the detachment of carnivores to be an independent subclass.

Order Arguloida Yamaguti, 1963
Argul Family>

From Wikipedia, the free encyclopedia

Scientific classification
A type:Arthropods
Latin name Branchiura Thorell, 1864 Childbirth
  • Agenor
  • Argulus
  • Binoculus
  • Chonopeltis
  • Diprosia
  • Dipteropeltis
  • Dolops
  • Gyropeltis
  • Huargulus
  • Moreiriella
  • Ozolus
  • Talaus

Carpoeids or carp lice (lat. Branchiura ) Is a subclass of crustaceans from the class Maxillopoda. Most representatives are ectoparasites of marine and freshwater fish; a small number parasitize on tadpoles of amphibians. Currently, about 200 species are described, united in a single family - Argul>


  1. 12 Ruppert E.E., Fox R.S., Barnes R.D., Invertebrate Zoology: Functional and Evolutionary Aspects. T. 3: Arthropods. - M.: Publishing Center "Academy", 2008. - 496 p.
  2. Martin J. W., Davis G. E. An Updated>

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Carp Eaters (Branchiura)

A very small detachment of ectoparasitic crustaceans living on the skin of fish. Strongly flattened in the dorsal - abdominal direction, the entire abdominal side is somewhat concave. The body consists of a fused head, four thoracic segments and a very short, whole abdomen. Antennals and antennas form small hook-shaped appendages. Mandibles give rise to a thin piercing proboscis, and the first pair of lower jaws is transformed into two powerful suckers, which serve to attach to the host. The most typical structure is retained by the second pair of lower jaws. In addition to the three naupliy ocelli, there are a pair of complex eyes.

Carp-eaters have the ability to swim freely and therefore can temporarily leave their owners.

Carp beetle (Argulus foliaceus), or carp louse (Fig. 285), parasitizes on carps and other freshwater fish, sometimes causing death of fish in carp pond farms.

See also in other dictionaries:

CARPOEEDS - (cyprinid lice), a detachment of ectoparasitic crustaceans (see Crustacea). The length of the body does not exceed 2 cm. Carapax (see KARAPAKS) is flattened, the abdomen is not divided into segments and devoid of limbs. In connection with the parasitic lifestyle, the head ... ... Encyclopedic Dictionary

Carpoeids - carp lice (Branchiura), a squad of crustaceans. 6 genera with 130 species, including the genus Argulus includes 109 species. Parasitize on the surface of the body and gills of fish, less often amphibians. Body length up to 3 cm. Dioecious. From those postponed by females ... ... Great Soviet Encyclopedia

Squad Carpoeidae or Carp Lice (Branchiura) - In freshwater fish, not only copepods are parasitic. Often on the surface of their bodies, especially where the skin is thinner and not so strong currents washing the fish water, that is, behind the gill covers and pectoral fins, you can ... ... Biological Encyclopedia

Copepods special squad of crustaceans * - The copepods (Copepoda, see the appendix table) make up a special detachment of crustaceans (Crustacea) from the subclass Entomostraca, to which exclusively small forms of crustaceans belong, partly parasitic, partly leading a free life in a fresh and ... ... Encyclopedic Dictionary F.A. Brockhaus and I.A. Efron

Copepods, a special squad of crustaceans - The copepods (Copepoda, see the appendix table) make up a special detachment of crustaceans (Crustacea) from the subclass Entomostraca, to which exclusively small forms of crustaceans belong, partly parasitic, partly leading a free life in a fresh and ... ... Encyclopedic Dictionary F.A. Brockhaus and I.A. Efron

CARP LICE - CARP LICE, the same as carpoeids (see CARPOEDA) ... Encyclopedic Dictionary

Jawbone -? Maxillopoda Cyclops of the genus Cyclops Scientific classification Kingdom ... Wikipedia

Maxillopoda - Cyclops from the genus Cyclops ... Wikipedia

Gill-tailed - (Branchiura) a detachment of invertebrate animals of the crustacean class, the same as the Carpoids ... Great Soviet Encyclopedia

CARP LICE - carpoeids (Branchiura), a subclass (according to another system, detachment) of crustaceans. Parasitize on the skin and gills of fish. 60 species. The body is very flattened, consists of the jawbone, 4 free thoracic segments and a short abdomen, merged with a fork. Che ... ... Biological Encyclopedic Dictionary

Arthropods - Scientific classification ... Wikipedia

Maxillopods -? Jawbone Cyclops Scientific Classification Kingdom: Animals Type: Arthropod ... Wikipedia

Arthropod -? Arthropods Scientific classification Kingdom: Animals Sub Kingdom: Eumetazoi Section ... Wikipedia

Hematophagous - (from other Greek. Αἷμα blood + φάγος food lover) animals that feed on the blood of other animals and humans. Hematophages can be carriers of certain pathogenic agents. Hematophagy is one of the most common forms ... ... Wikipedia

Ectoparasites of fish - parasitic organisms that have adapted to exist on the outer covers of fish and have retained a direct connection with the external environment. E. fish are small flukes gyrodactylus that settle on the skin and destroy it, parasitic ... ... Pond fish farming


Argulus have horseshoe-shaped head shields covering the lobes of the carapace. The shape of the carapace varies by species. In A.coregoni, only the first three pairs of limbs cover the lobes of carapace, while in A. japonicus, all four pairs of limbs. A small notch is observed at the junction of the lobes of the carapace and head shields.

On the ventral side of the carapace, there are two pairs of respiratory regions that are species-specific and serve to identify the species. They have a clear outline and, unlike the rest of the carapace, are covered with a thin cuticle. Five pairs of limbs are located on the cephalothorax. The first and second pairs are represented by antennals and antennas, respectively. Species-specific are the number and shape of spines and hooks covering these limbs. The third pair is the maxilla or sucker, consisting of sclerite sticks. The number of sticks varies depending on the type of carboed. The fourth pair is represented by mandibles, which include the proboscis or oral tube, a structure located posterior to the preoral spine between the suction cups. The next pair of limbs, i.e. maxillas, is located behind the suction cups. They are also characterized by a species-specific form of basal plates, the number of spines and scales. Four pairs of bifurcated swimming legs can be seen on the chest of the parasite. In males, the legs additionally perform the function of a copulative organ, which is morphologically different in different species. The posterior segment of the thallus is the abdomen.

The head section of the carpoed is shown in the illustration (60x magnification. Wim van Egmond. Micropolitan Museum of Rotterdam, Netherlands).

The illustration shows the structure of the female Argulus japonicus from the ventral side. Antenna (an), front respiratory region (ar), antennae (as), basal plate (bp), maxillus (ms), mouth tube (mt), maxilla (mt), posterior respiratory region (pr), preoral spike (ps) ), bifurcated swimming limbs (sl), sepriemnik (sp). Most of the previously reported reports of Argulus species in Europe appeared in response to the Infection of individuals in carp farms; in Germany, a special name for the parasites, “Carp Louse,” appeared. In most cases, the species A. foliaceus acts as a parasite, which is widespread in Europe, Siberia, and Central Asia, and only in isolated cases is A. coregoni, which also lives in the Far East. In turn, A. japonicus was introduced to Europe with the import of ornamental fish from Asia. This species is found in Western Europe, Asia, Ukraine, Amur Region and, along with A. coregoni, is a typical parasite of African rivers and lakes.

A. coregoni is twice as large as A. foliaceus; it has more pointed than rounded abdominal lobes. This species is very similar to A. foliaceus and can only be determined under a microscope.

A. foliaceus usually inhabits organically rich bodies of water, tolerance of salinity above 8-12 and temperatures above 25 ° C. As a rule, A. coregoni infects fish in rivers, streams and cold oligotrophic lakes with a strong current.

The parasites pierce the host's skin with a thin stylet and feeds on blood and skin using the proboscis and mandibles.

In addition to the harm that the carnivore himself causes when eating fish tissues, he opens the door to bacterial infections. In particular, F. columnare bacteria have been shown to be associated with infection with Argulus coregoni and increase host mortality. In dead fish, foci of necrosis are observed on the skin around the tail and dorsal fin, which are typical signs of columnariosis.

The occurrence of a secondary infection is associated, on the one hand, with a violation of the integrity of the skin and mucus, and, on the other hand, with stress and a decrease in the body's immune status.

Severe invasion of carboeda on the skin of koi carp (news.ifas.ufl.edu/) increases by click. Severe invasion of carboeda on the skin of koi carp (news.ifas.ufl.edu/) increases by click.


Infected fish are losing weight and their value for sport fishing and the fishing industry is greatly reduced. Running infection causes noticeable changes in behavior. At an early stage of the disease, the lake fish moves spasmodically in an attempt to get rid of the parasite. As a result, food consumption is reduced, the mass of individuals is reduced, and it becomes difficult to fish them out. Later, the infected fish begins to climb into inaccessible shallows, mortality increases.

In the upper illustration, cargoids Argulus coregoni (length 15 mm, left) and Argulus
foliaceus (right), on the lower A. foliaceus female (left) and male (right).

Carpaeide breeding

Argulus spp. reproduce sexually, male and female can mate on the host, or outside of it. The adult female has one, located in the middle, the ovary, which runs throughout the body. Although several mating may occur, only one is sufficient to fertilize all eggs. The sex of the individuals is easily determined by the large dark spots present on the male on each abdominal lobe. The female, in turn, has spotted pigmentation of the central part of the dorsal surface of the carapace, covering the ovary www.thefishsite.com/articles/319/fish-lice-in-the-uk.

Pregnant female Argulus spp. detaches from the fish and begins to look for a solid substrate for the eggs. The substrate is usually a vertical flat surface of stones. This area, as free as possible from algae growth and dirt, eliminates the burial of eggs.On the other hand, it is possible that the female is more often found with vertically located stones and therefore leaves eggs on them. The masonry is attached by a gelatinous substance that hardens upon contact with water. The eggs of A. foliaceus and A. japonicus consist of groups arranged in 2-4 rows, with a total number of 400 pieces, while A. coregoni lays 900 eggs in a continuous layer. It is worth noting that, unlike A. foliaceus, who prefers to lay in shallow water, A. coregoni lays eggs in deeper areas of the reservoir. This is consistent with data on the preference of certain hosts for parasites, when A. foliaceus predominantly infects cyprinids and perch, mainly living in shallow water, and A. coregoni, salmonids living in deep-sea areas with a high oxygen content.

Specificity in the choice of a host in ectoparasites is observed only at puberty. In a study conducted on Finnish lakes with A. foliaceus and A. coregoni, it was shown that young individuals of both species exhibit low specificity and attach mainly to fish, whose body reflects light well. However, an adult A. coregoni of 4-5 mm length preferred rainbow trout rather than roach, which did not depend on the host on which the parasite had previously developed.

In the illustration, the life cycle of Argulus coregoni, Metanauplius (0.7 mm long), emerged from masonry on stone (1), free-floating methanauplius searches for a host (2), attached carpoids, develop on fish (3), adult male (4) and female (5) mate on fish (length 4-14 mm), after which the female lays eggs on a stone. In the illustration, the metanauplius A. foliaceus leaves the masonry. Carp-eaters are capable of producing over 10 clutches, but in most cases it lays only one. The eggs are oval 0.2x0.3 mm. Immediately after laying, they are white or pale yellow, but after 24 hours they turn dark yellow / light brown. The eggs adhere to the substrate and, unlike the snails, do not have a common gelatinous mass covering the entire masonry. Parasites that appear at the larval stage are called metanauplii and have a length of 0.6-0.8 mm.

The incubation period depends on temperature, with its increase it decreases (usually 3-5 weeks in A. foliaceus). At 8-10 ° C, the eggs of three species do not hatch, which is associated with an adaptive mechanism that is designed to activate the appearance of the parasite in a favorable spring-summer time. Wintering masonry has much poorer carboeda yield, but at low temperatures it can remain viable for more than 2 years.

The number of parasites on fish tends to decrease in winter, which is confirmed in experiments in which carpoeids died in cold conditions and after breeding. Spring temperature fluctuations and sunlight activate egg maturation. This previous generation gives rise to subsequent generations, causing a peak in the population in late summer and early fall. With a drop in temperature in the winter, the population decreases sharply. Adult individuals surviving wintering are observed only in A. foliaceus, they become relatively inactive until the water warms up above 10 ° C, when they can leave the host and begin to lay eggs.

Tracking prey by a carnivore

Of particular interest is the strategy of hunting down the owner of a carnivore. In particular, work was carried out with the species Argulus foliaceus, which shows the differentiation of search behavior depending on lighting. The study determined the method used by the parasite for night searches, when the level of Infection is maximum and the stimuli emitted by the fish are important. Changing lighting greatly changes the search behavior of the female Argulus. The average speed of movement and the area under investigation increase 3-4 times in the dark, while the parasite uses a cruising search strategy. In the light, the ambush strategy of concealment and attack acts as the main one. The most pronounced differences caused by light in the search behavior are observed in a hungry carpoeater (starving for 24-96 hours). Less motivated (having just left the host) and being on a fish, the parasite does not show differences in the change in the speed of movement day and night. Among the external signals in the work, the smell of fish was used, from perch (Perca fluviatilis) and roach (Rutilus rutilus), it caused an acceleration of the parasite. Periodically switched on flow led to a similar, but weaker effect. The researchers concluded that the search behavior of A. foliaceus is controlled by internal (hungry, well-fed) and external factors (lighting, signals from fish) and includes all the sensory systems of the parasite (vision, smell, mechanoreception). Perch (but not roach) reduces the speed of movement in the dark, which makes it more susceptible to infection.

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University of Jyväskylä, 2007

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