''Galactosomum'' is a
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
of
flukes in the family
Heterophyidae
Heterophyidae is a family of intestinal trematodes in the order Plagiorchiida.
Description: " Tegument covered by spines. Oral sucker not armed or armed by cyrcumoral spines. Pharynx presented. Genital synus presented. Ventral and genital suc ...
. There are currently 28 recognised
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
within the genus. They mainly infect
aquatic birds
Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweigh ...
, but often infest
fish
Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of li ...
as
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. Three species are known to use
marine mammals
Marine mammals are aquatic mammals that rely on the ocean and other marine ecosystems for their existence. They include animals such as seals, whales, manatees, sea otters and polar bears. They are an informal group, unified only by their relia ...
as hosts.
Description
The excised spherical
metacercaria
Trematodes are parasitic flatworms of the class ''Trematoda'', specifically parasitic flukes with two suckers: one ventral and the other oral. Trematodes are covered by a tegument, that protects the organism from the environment by providing secr ...
is 2.7–4.9 mm long.
Generally, only one is found per fish.
Life cycle
Some species of ''Galactosomum'' cause infected fish to swim closer to the surface and colorfully flash their underbellies.
In fish, symptoms can be similar to those of
whirling disease
''Myxobolus cerebralis'' is a myxosporean parasite of salmonids (salmon and trout species) that causes whirling disease in farmed salmon and trout and also in wild fish populations. It was first described in rainbow trout in Germany in 1893, b ...
caused by the unrelated parasite ''
Myxobolus cerebralis''.
hosting select species suffer from sensory impairment due to infestation. This makes these
prey animals more likely to be consumed by aquatic birds, providing a host for the parasite to reach the mature stage of its life cycle. ''Galactosomum'' cannot survive in human hosts.
Species
*''
Galactosomum baylisi''
(Gohar, 1930)
*''
Galactosomum bearupi''
Pearson, 1973
*''
Galactosomum cochlear''
(Diesing, 1850) Travassos, 1929
*''
Galactosomum cochleariforme''
(Rudolphi, 1819) Pratt, 1911
*''
Galactosomum darbyi''
Price, 1934
*''
Galactosomum dollfusi''
Pearson, 1973
*''
Galactosomum echinatum''
(Timon-David, 1955)
*''
Galactosomum erinaceum''
(Poirier, 1886)
*''
Galactosomum fregatae''
(Prudhoe, 1949)
*''
Galactosomum humbargari''
Park, 1936
*''
Galactosomum johnsoni''
(Price, 1934)
*''
Galactosomum lacteum''
(Jägerskiöld, 1896)
*''
Galactosomum linguiforme''
Anantaraman, 1974
*''
Galactosomum nicolai''
(Isaichikov, 1927)
*''
Galactosomum palawanense''
Fischthal & Kuntz, 1972
*''
Galactosomum phalacrocoracis''
Yamaguti, 1939
*''
Galactosomum puffini
''Galactosomum'' is a genus of flukes in the family Heterophyidae. There are currently 28 recognised species within the genus. They mainly infect aquatic birds
Birds are a group of warm-blooded vertebrates constituting the class Aves ...
''
Yamaguti, 1941
*''
Galactosomum renincola''
Pearson, 1973
*''
Galactosomum sanaense''
Kobayashi, 1942
*''
Galactosomum semifuscum''
(Olsson, 1876)
*''
Galactosomum sinuilactis
''Galactosomum'' is a genus of flukes in the family Heterophyidae. There are currently 28 recognised species within the genus. They mainly infect aquatic birds, but often infest fish as larvae. Three species are known to use marine mammals as h ...
''
Pearson, 1973
*''
Galactosomum spinetum''
(Braun, 1901)
*''
Galactosomum stelleri''
Dailey, Demaree & Critchfield, 2002
*''
Galactosomum timondavidi''
Pearson & Prévot, 1971
*''
Galactosomum ubelakeri
''Galactosomum'' is a genus of flukes in the family Heterophyidae. There are currently 28 recognised species within the genus. They mainly infect aquatic birds, but often infest fish as larvae. Three species are known to use marine mammals as h ...
''
(Dailey, 1969) Pearson, 1977
*''
Galactosomum ussuriense''
Oshmarin, 1963
*''
Galactosomum witenbergi''
Anantaraman, 1974
*''
Galactosomum yehi''
(Dissanaike, 1961) Pearson, 1973
References
External links
Heterophyidae
Suicide-inducing parasitism
{{Trematoda-stub