Argulus foliaceus | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Subphylum: | Crustacea |
Class: | Ichthyostraca |
Order: | Arguloida |
Family: | Argulidae |
Genus: | Argulus |
Species: | A. foliaceus |
Binomial name | |
Argulus foliaceus | |
Synonyms | |
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Argulus foliaceus, also known as the common fish louse, is a species of fish lice in the family Argulidae. [1] It is "the most common and widespread native argulid in the Palaearctic" [2] and "one of the most widespread crustacean ectoparasites of freshwater fish in the world", considering its distribution and range of hosts. [3] It can cause the severe disease state argulosis in a wide variety of fish species. It is responsible for epizootic outbreaks that have led to the collapse of aquaculture operations. [2] Fish lice are not related to lice, which are insects.
A typical fish louse of the genus Argulus is very flat with an oval or rounded carapace, two compound eyes, sucking mouthparts with a piercing stylet, and two suction cups it uses to attach to its host. [4] These "suctorial organs" are the first of its two pairs of maxillae, modified in shape. [5] Its paired appendages have hooks and spines, [4] and are used for swimming. [5] A. foliaceus in particular is up to 7 millimeters long by 5 millimeters wide. [5] The female is larger than the male and has a visible pair of spermathecae on its posterior end, in which the male deposits sperm. [4]
The common fish louse lives in marine, brackish, and freshwater environments. [5] All life stages of both sexes are parasitic. [4] It attaches to its host, usually a fish, via its suction cups, pierces the skin with its sharp stylet, and feeds on blood. [5] It may live in the gills. [6] A heavy infestation causes inflammation of the skin, open hemorrhaging wounds, increased production of mucus, loss of scales, and corrosion of the fins. The wounds are often infected with bacteria and fungi, which further degrade the skin layers. [5] The fish can become anemic. During feeding, the louse also injects digestive enzymes into the flesh. Infested fish may exhibit loss of appetite and slowed growth, and behavioral signs such as erratic swimming and rubbing up against aquarium walls. [6] The damage and infection cause stress and mortality. [7]
The common fish louse is also a vector for pathogens, introducing organisms such as bacteria, flagellates, and the virus that causes spring viraemia of carp. It is an intermediate host to nematodes of the family Skrjabillanidae. [8]
To locate its host, the fish louse uses vision, olfaction, and mechanical sensation. During light hours it searches visually for a host, usually remaining still in ambush. When it is dark the louse is more active, swimming about to encounter a host. It senses the smell of the fish and the movement of the water around it. It also becomes more active in searching when it has not fed in over 24 hours. [9]
During the reproductive cycle, the male and female fish louse copulate upon the body of the host, and the female detaches every few days to swim to the substrate and lay eggs. It favors hard strata, and its eggs can be collected by providing it with a wooden board to lay them on. It lays more clutches during daylight hours than at night. [7]
The larva of the fish louse has two main stages. In its newly hatched stage it has been termed a "metanauplius", like the nauplius of many other crustaceans, but with a swimming apparatus that is more developed. It may even be too well developed for the larva to be called a nauplius at all. [10] The newly hatched larva can parasitize a host, attaching to it with its hooked antennae because it lacks suction cups. A second function of its hook-lined antennae is an apparent grooming behavior, in which it drags the antennae across the setae of its swimming legs to dislodge debris. In the second main stage, after its first molt, it is simply called a "juvenile", because it is very similar to the adult, only smaller. It can swim just as efficiently as the adult. [10] The larva molts eleven times before reaching adulthood. [4]
This parasite "has been recorded from practically every freshwater fish species within its natural range". [11] Food and sport fish and other commercially important species parasitized include carp and minnows such as goldfish and koi, members of the sunfish family, and salmonids such as salmon and trout. [4] Hosts include blue bream (Ballerus ballerus), silver bream (Blicca bjoerkna), European eel (Anguilla anguilla), northern pike (Esox lucius), three-spined stickleback (Gasterosteus aculeatus), pumpkinseed (Lepomis gibbosus), ide (Leuciscus idus), abu mullet (Liza abu), European perch (Perca fluviatilis), common roach (Rutilus rutilus), common rudd (Scardinius erythropthalmus), wels catfish (Silurus glanis), zander (Sander lucioperca), tench (Tinca tinca), and Atlantic horse mackerel (Trachurus trachurus). [12]
While it is a generalist parasite not specific to a host taxon, it does display preferences, apparently preferring larger and heavier fish over smaller, [13] and certain species over others when given a choice. [14]
It has also been observed on frogs and toads. [4]
Heavy infestations in fish stocks can lead to large-scale losses. Major outbreaks in rainbow trout fisheries in the United Kingdom have resulted in total losses. [7] Carp aquaculture in Russia has experienced infestations in which fish were coated in "several hundred" parasites before dying. [14] Parasites infested 100% of the fish in a sample at a stricken carp farm in Turkey, with up to 1000 fish lice per individual. [15]
The fish louse will readily lay its eggs on hard objects such as wooden boards, and these can be removed from the water to reduce the egg load in the fishery. [7] A short bath in a sodium chloride solution can reduce the parasite load on a fish, but this treatment must be done carefully, because too short a duration or too dilute a solution is ineffective, while too long or too concentrated a bath can harm the fish. [16]
The crab louse or pubic louse is an insect that is an obligate ectoparasite of humans, feeding exclusively on blood. The crab louse usually is found in the person's pubic hair. Although the louse cannot jump, it can also live in other areas of the body that are covered with coarse hair, such as the perianal area, the entire body, and the eyelashes.
Pediculosis is an infestation of lice from the sub-order Anoplura, family Pediculidae. Accordingly, the infestation with head lice is named pediculosis capitis, while this with body lice, pediculosis corporis. Although pediculosis in humans may properly refer to lice infestation of any part of the body, the term is sometimes used loosely to refer to pediculosis capitis, the infestation of the human head with the specific head louse.
The head louse is an obligate ectoparasite of humans. Head lice are wingless insects that spend their entire lives on the human scalp and feed exclusively on human blood. Humans are the only known hosts of this specific parasite, while chimpanzees and bonobos host a closely related species, Pediculus schaeffi. Other species of lice infest most orders of mammals and all orders of birds.
The family Argulidae, whose members are commonly known as carp lice or fish lice, are parasitic crustaceans in the class Ichthyostraca. It is the only family in the monotypic subclass Branchiura and the order Arguloida, although a second family, Dipteropeltidae, has been proposed. Although they are thought to be primitive forms, they have no fossil record.
The Pentastomida are an enigmatic group of parasitic arthropods commonly known as tongue worms due to the resemblance of the species of the genus Linguatula to a vertebrate tongue; molecular studies point to them being degenerate crustaceans.
Sea lice are copepods of the family Caligidae within the order Siphonostomatoida. They are marine ectoparasites that feed on the mucus, epidermal tissue, and blood of host fish. The roughly 559 species in 37 genera include around 162 Lepeophtheirus and 268 Caligus species.
The body louse is a hematophagic ectoparasite louse that infests humans. It is one of three lice which infest humans, the other two being the head louse, and the crab louse or pubic louse.
Opisthorchis felineus, the Siberian liver fluke or cat liver fluke, is a trematode parasite that infects the liver in mammals. It was first discovered in 1884 in a cat's liver by Sebastiano Rivolta of Italy. In 1891, Russian parasitologist, Konstantin Nikolaevich Vinogradov (1847–1906) found it in a human, and named the parasite a "Siberian liver fluke". In the 1930s, helminthologist Hans Vogel of Hamburg published an article describing the life cycle of Opisthorchis felineus. Felineus infections may also involve the pancreatic ducts. Diagnosis of Opisthorchis infection is based on microscopic identification of parasite eggs in stool specimens. Safe and effective medication is available to treat Opisthorchis infections. Adequately freezing or cooking fish will kill the parasite.
The salmon louse is a species of copepod in the genus Lepeophtheirus. It is a sea louse, a parasite living mostly on salmon, particularly on Pacific and Atlantic salmon and sea trout, but is also sometimes found on the three-spined stickleback. It feeds on the mucus, skin and blood of the fish. Once detached, they can be blown by wind across the surface of the sea, like plankton. When they encounter a suitable marine fish host, they adhere themselves to the skin, fins, or gills of the fish, and feed on the mucus or skin. Sea lice only affect fish and are not harmful to humans.
Dactylogyrus is a genus of monogeneans in the Dactylogyridae family.
Dactylogyrus vastator is a species of hermaphroditic flatworms of class Monogenea. It is an ectoparasite of fish which infests the gills. It is problematic on fish farms. It is otherwise non-hazardous to humans.
Bothriocephalus acheilognathi, also known as the Asian tapeworm, is a freshwater fish parasite that originated from China and Eastern Russia. It is a generalized parasite that affects a wide variety of fish hosts, particularly cyprinids, contributing to its overall success.
Dipteropeltis hirundo is a little-known species of fish louse. It is an ectoparasite of fish found in South America, including piranhas and barred sorubim.
Crustaceans may pass through a number of larval and immature stages between hatching from their eggs and reaching their adult form. Each of the stages is separated by a moult, in which the hard exoskeleton is shed to allow the animal to grow. The larvae of crustaceans often bear little resemblance to the adult, and there are still cases where it is not known what larvae will grow into what adults. This is especially true of crustaceans which live as benthic adults, more-so than where the larvae are planktonic, and thereby easily caught.
Argulus is a genus of fish lice in the family Argulidae. There are about 140 accepted species in the genus Argulus. They occur in marine, brackish, and freshwater environments. They sit tightly against the host body, this minimises risk of detachment. As juveniles, these species feed on mucous and skin cells of their host. With age they become blood feeders because the parasite moves from feeding on the fins to feeding on the body of the fish, causing the feeding change. At least some species can have severe impacts on their host populations.
Trichodectes canis, also known as canine chewing louse, is a chewing louse found on domesticated dogs and wild canids throughout the world. T. canis is a well-known vector for the dog tapeworm, Dipylidium caninum. T. canis usually does not present any major problems to the host, however, can be very irritating in heavy infestations. In North America and most developed countries, T. canis infestation of domesticated dogs is very uncommon as long as they are properly cared for and healthy. Poorly taken care of dogs are more prone to getting a lice infestation.
Argulus japonicus, also known as the Japanese fish louse, is a species of crustacean in the family Argulidae. This species is light brown in colour and may be between 4 and 9 mm long and 3 to 6 mm wide. It has a stumpy tail, and is shaped somewhat like a round shield. The female and male are phenotypically distinct, categorizing them as a dioecious species. Although they are not drastically different, their transparent skin highlights the minor differences such as the different copulatory accessories.
Oligostraca is a superclass of crustaceans. It consist of the following three classes:
Chonopeltis is a genus of fish lice in the subclass Branchiura. These crustaceans are ectoparasitic and spend most of their lives on the body of an aquatic host. Species of this genus are found exclusively in Africa, and inhabit freshwater rivers.
The carp louse Argulus coregoni is an obligate ectoparasitic branciuran species on fish. It occurs in China and Japan, and Scandinavia. Argulus coregoni can pose a threat to fish kept in fish farms.