Whale louse
Encyclopedia
A whale louse is a parasitic
crustacean
of the family Cyamidae. They are related to the better-known skeleton shrimp
, most species of which are found in shallower waters. Whale lice are external parasites, found in skin lesions, genital folds, nostril
s and eyes of marine mammal
s of the order Cetacea
. These include not only whale
s but also dolphin
s and porpoise
s.
. They remain with their host throughout their development and do not experience a free-swimming phase. Although the relationship between a specific species of whale louse and a specific species of whale is more pronounced with baleen whale
s than with toothed whale
s, almost every species of whale has a louse species that is unique to it. With the sperm whale
, the parasitic relationship is sex-specific. The whale louse Cyamus catodontis lives exclusively on the skin of the male, while Neocyamus physeteris is found only on females and calves.
Whale lice attach themselves to the host body in places that protect them from water currents, so they can be found in natural body openings and in wounds; with baleen whales they are found primarily on the head and in the ventral pleats. Around 7,500 whale lice live on a single whale.
With some species of whale lice, barnacle
infestation plays an important role. Species like Cyamus rhachianecti settle directly where the barnacles attach to the whale and consume so much of the surrounding area that the barnacles fall off. On the right whale
, the parasites live mainly on callosities
(raised callus-like patches of skin on the whales' heads). The clusters of white lice contrast with the dark skin of the whale, and help researchers identify individual whales because of the lice clusters' unique shapes.
The lice predominantly eat algae
that settle on the host's body. They usually feed off the flaking skin of the host, and frequent wounds or open areas. They cause minor skin damage, but this does not lead to significant illness.
The development of the whale louse is closely connected with the life pattern of whales. The distribution of various lice species reflects migratory patterns.
Cyamus Latreille, 1796
Isocyamus Gervais & van Beneden, 1859
Neocyamus Margolis, 1955
Platycyamus
Lütken, 1870
Scutocyamus Lincoln & Hurley, 1974
Syncyamus Bowman, 1955
Parasitism
Parasitism is a type of symbiotic relationship between organisms of different species where one organism, the parasite, benefits at the expense of the other, the host. Traditionally parasite referred to organisms with lifestages that needed more than one host . These are now called macroparasites...
crustacean
Crustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
of the family Cyamidae. They are related to the better-known skeleton shrimp
Skeleton shrimp
Skeleton shrimp are marine crustaceans of the infraorder Caprellida. The name denotes the threadlike slender body which allows them to virtually disappear among the fine filaments of seaweed, hydroids and bryozoans.-Ecology:...
, most species of which are found in shallower waters. Whale lice are external parasites, found in skin lesions, genital folds, nostril
Nostril
A nostril is one of the two channels of the nose, from the point where they bifurcate to the external opening. In birds and mammals, they contain branched bones or cartilages called turbinates, whose function is to warm air on inhalation and remove moisture on exhalation...
s and eyes of marine mammal
Marine mammal
Marine mammals, which include seals, whales, dolphins, and walruses, form a diverse group of 128 species that rely on the ocean for their existence. They do not represent a distinct biological grouping, but rather are unified by their reliance on the marine environment for feeding. The level of...
s of the order Cetacea
Cetacea
The order Cetacea includes the marine mammals commonly known as whales, dolphins, and porpoises. Cetus is Latin and is used in biological names to mean "whale"; its original meaning, "large sea animal", was more general. It comes from Ancient Greek , meaning "whale" or "any huge fish or sea...
. These include not only whale
Whale
Whale is the common name for various marine mammals of the order Cetacea. The term whale sometimes refers to all cetaceans, but more often it excludes dolphins and porpoises, which belong to suborder Odontoceti . This suborder also includes the sperm whale, killer whale, pilot whale, and beluga...
s but also dolphin
Dolphin
Dolphins are marine mammals that are closely related to whales and porpoises. There are almost forty species of dolphin in 17 genera. They vary in size from and , up to and . They are found worldwide, mostly in the shallower seas of the continental shelves, and are carnivores, mostly eating...
s and porpoise
Porpoise
Porpoises are small cetaceans of the family Phocoenidae; they are related to whales and dolphins. They are distinct from dolphins, although the word "porpoise" has been used to refer to any small dolphin, especially by sailors and fishermen...
s.
Appearance
The body of a whale louse is distinctly flat and considerably reduced at the rear. Its legs, especially the back three pairs of legs, have developed into claw-like protuberances with which it clings to its host. Its length ranges from 5 to 25 mm (0.196850393700787 to 0.984251968503937 in) depending on the species.Way of life
Most species of whale lice are associated with a single species of whaleWhale
Whale is the common name for various marine mammals of the order Cetacea. The term whale sometimes refers to all cetaceans, but more often it excludes dolphins and porpoises, which belong to suborder Odontoceti . This suborder also includes the sperm whale, killer whale, pilot whale, and beluga...
. They remain with their host throughout their development and do not experience a free-swimming phase. Although the relationship between a specific species of whale louse and a specific species of whale is more pronounced with baleen whale
Baleen whale
The Baleen whales, also called whalebone whales or great whales, form the Mysticeti, one of two suborders of the Cetacea . Baleen whales are characterized by having baleen plates for filtering food from water, rather than having teeth. This distinguishes them from the other suborder of cetaceans,...
s than with toothed whale
Toothed whale
The toothed whales form a suborder of the cetaceans, including sperm whales, beaked whales, dolphins, and others. As the name suggests, the suborder is characterized by the presence of teeth rather than the baleen of other whales.-Anatomy:Toothed whales have a single blowhole on the top of the head...
s, almost every species of whale has a louse species that is unique to it. With the sperm whale
Sperm Whale
The sperm whale, Physeter macrocephalus, is a marine mammal species, order Cetacea, a toothed whale having the largest brain of any animal. The name comes from the milky-white waxy substance, spermaceti, found in the animal's head. The sperm whale is the only living member of genus Physeter...
, the parasitic relationship is sex-specific. The whale louse Cyamus catodontis lives exclusively on the skin of the male, while Neocyamus physeteris is found only on females and calves.
Whale lice attach themselves to the host body in places that protect them from water currents, so they can be found in natural body openings and in wounds; with baleen whales they are found primarily on the head and in the ventral pleats. Around 7,500 whale lice live on a single whale.
With some species of whale lice, barnacle
Barnacle
A barnacle is a type of arthropod belonging to infraclass Cirripedia in the subphylum Crustacea, and is hence related to crabs and lobsters. Barnacles are exclusively marine, and tend to live in shallow and tidal waters, typically in erosive settings. They are sessile suspension feeders, and have...
infestation plays an important role. Species like Cyamus rhachianecti settle directly where the barnacles attach to the whale and consume so much of the surrounding area that the barnacles fall off. On the right whale
Right whale
Right whales are three species of large baleen whales consisting of two genera in the family Balaenidae of order Cetacea. Their bodies are very dark gray or black and rotund....
, the parasites live mainly on callosities
Callosity
A callosity is another name for callus, a piece of skin that has become thickened as a result of repeated contact and friction.- Monkeys :When occurring on an animal's buttocks, as with baboons, they are specifically called ischial callosities...
(raised callus-like patches of skin on the whales' heads). The clusters of white lice contrast with the dark skin of the whale, and help researchers identify individual whales because of the lice clusters' unique shapes.
The lice predominantly eat algae
Algae
Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many...
that settle on the host's body. They usually feed off the flaking skin of the host, and frequent wounds or open areas. They cause minor skin damage, but this does not lead to significant illness.
The development of the whale louse is closely connected with the life pattern of whales. The distribution of various lice species reflects migratory patterns.
Species
Currently, 31 species are recognised:Cyamus Latreille, 1796
- Cyamus antarcticensis Vlasova, 1982
- Cyamus bahamondei Buzeta, 1963
- Cyamus balaenopterae K. H. Barnard, 1931
- Cyamus boopis Lütken, 1870
- Cyamus catodontis Margolis, 1954
- Cyamus ceti (Linnaeus, 1758)
- Cyamus erraticus Roussel de Vauzème, 1834
- Cyamus eschrichtii Margolis, McDonald & Bousfield, 2000
- Cyamus gracilis Roussel de Vauzème, 1834
- Cyamus kessleri A. Brandt, 1873
- Cyamus mesorubraedon Margolis, McDonald & Bousfield, 2000
- Cyamus monodontis Lutken, 1870
- Cyamus nodosus Lutken, 1861
- Cyamus orcini Leung, 1970
- Cyamus orubraedon Waller, 1989
- Cyamus ovalis Roussel de Vauzème, 1834
- Cyamus rhytinae (J. F. Brandt, 1846)
- Cyamus scammoni Dall, 1872
Isocyamus Gervais & van Beneden, 1859
- Isocyamus antarcticensis Vlasova in Berzin & Vlasova, 1982
- Isocyamus delphinii Guérin Méneville, 1836
- Isocyamus deltabrachium Sedlak-Weinstein, 1992
- Isocyamus kogiae Sedlak-Weinstein, 1992
Neocyamus Margolis, 1955
- Neocyamus physeteris (Pouchet, 1888)
Platycyamus
Platycyamus
Platycyamus is a genus of flowering plants in the legume family, Fabaceae. It belongs to the sub family Faboideae....
Lütken, 1870
- Platycyamus flaviscutatus Waller, 1989
- Platycyamus thompsoni (Gosse, 1855)
Scutocyamus Lincoln & Hurley, 1974
- Scutocyamus antipodensis Lincoln & Hurley, 1980
- Scutocyamus parvus Lincoln & Hurley, 1974
Syncyamus Bowman, 1955
- Syncyamus aequus Lincoln & Hurley, 1981
- Syncyamus chelipes (Costa, 1866)
- Syncyamus ilheusensis Haney, De Almeida & Reid, 2004
- Syncyamus pseudorcae Bowman, 1955