A whale louse is a crustacean of the family Cyamidae. Despite the name, it is not a true louse (which are insects), but rather is related to the skeleton shrimp, most species of which are found in shallower waters. Whale lice are external parasites, found in skin lesions, genital folds, nostrils and eyes of marine mammals of the order Cetacea. These include not only whales but also dolphins and porpoises.
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 depending on the species.
Life cycle Most species of whale louse are associated with a single species of whale. They remain with their host throughout their development and will never 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 whales than with toothed whales, 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. Cited in:
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. Up to 7,500 whale lice can live on a single whale.
With some species of whale louse, whale barnacle infestations play an important role. 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 louse 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 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
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