Mermithidae is a family of
nematode worms that are
endoparasite
Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has c ...
s in
arthropod
Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a Segmentation (biology), segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and Arth ...
s. As early as 1877, Mermithidae was listed as one of nine subdivisions of the Nematoidea. Mermithidae are confused with the horsehair worms of the phylum
Nematomorpha
Nematomorpha (sometimes called Gordiacea, and commonly known as horsehair worms, hairsnakes, or Gordian worms) are a phylum of parasitoid animals superficially similar to nematode worms in morphology, hence the name. Most species range in siz ...
that have a similar life history and appearance.
Mermithids are parasites, mainly of
arthropods
Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and cuticle made of chitin, oft ...
. Most are known from insects, but some are recorded from spiders, scorpions and crustaceans. A few are known to parasitize earthworms, leeches and molluscs, and a specimen is known from a spider preserved in Baltic amber.
At least 25 species are known to parasitize mosquito larvae, making them of considerable interest in
biological control
Biological control or biocontrol is a method of controlling pests, such as insects, mites, weeds, and plant diseases, using other organisms. It relies on predation, parasitism, herbivory, or other natural mechanisms, but typically als ...
.
A species, probably ''
Pheromermis vesparum'', was recorded from the invasive
Asian hornet (''Vespa velutina'') in France. The parasite was considered to be a member of the local fauna which had adapted to a new
host. However, the authors concluded that the mermithid could not hamper the hornet invasion nor be used in biological control programs against this
invasive species
An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species adv ...
.
Life history
Mermithids are wire-like and have a smooth
cuticle with layers of spiral fibres. The digestive tract is similar to that of free-living nematodes only in the young larvae prior to their parasitic life; in the parasitic stages the
oesophagus
The esophagus (American English) or oesophagus (British English; both ), non-technically known also as the food pipe or gullet, is an Organ (anatomy), organ in vertebrates through which food passes, aided by Peristalsis, peristaltic contracti ...
is disconnected from the mid-intestine, and females lack an anus. The female genital opening is at the midbody, while the male opening is at the tip and visible as one or two spicules. The eggs are laid either in water or on land, and the newly hatched larvae are free-living, as are the adults that emerge from the hosts to lay eggs.
The taxonomy of the group has been confused due to poor specimen collection as well as very limited morphological characteristics, and most are discovered by entomologists rather than nematologists. Even the best-studied species, ''Romanomermis culicivorax'', has an unclear taxonomic status.
Host behavior alteration
Mermithid nematodes induce water-seeking behavior in their hosts, by relying on altering the host's
hemolymph
Hemolymph, or haemolymph, is a fluid, analogous to the blood in vertebrates, that circulates in the interior of the arthropod (invertebrate) body, remaining in direct contact with the animal's tissues. It is composed of a fluid plasma in which ...
osmolality (concentration of salt) to achieve the same effect.
Included genera
These genera are included in the family:
* ''
Abathymermis''
Rubtsov, 1871
* ''
Aranimermis''
* †''
Cretacimermis''
Poinar, 2001
*''
Eumermis
''Eumermis'' is a genus of nematodes belonging to the family Mermithidae.
Species:
* ''Eumermis pangodiensis
''Eumermis'' is a genus of nematodes belonging to the family Mermithidae
Mermithidae is a family of nematode worms that are endo ...
''
Daday, 1911
*''
Gastromermis
''Gastromermis'' is a genus of nematodes belonging to the family Mermithidae.
Species:
* ''Gastromermis abaquatilis'' Rubzov & Gafurov, 1977
* ''Gastromermis acroamphidis
''Gastromermis'' is a genus of nematodes belonging to the family Mer ...
''
Micoletzky, 1923
* †''
Heydenius''
Taylor, 1935
* ''
Hydromermis
''Hydromermis'' is a genus of '' Mermithidae''.
The genus was described in 1902 by Corti.
Species:
* ''Hydromermis contorta''
* ''Hydromermis grandis
''Hydromermis'' is a genus of ''Mermithidae''.
The genus was described in 1902 by Corti.
...
''
Corti, 1902
*''
Lanceimermis
''Lanceimermis'' is a genus of nematodes belonging to the family Mermithidae.
Species:
* ''Lanceimermis austriaca'' (Micoletzky, 1914)
* ''Lanceimermis baikalensis
''Lanceimermis'' is a genus of nematodes belonging to the family Mermithi ...
''
Artyukhovskii, 1969
* ''
Mermis''
Dujardin, 1842
* ''
Pheromermis''
Poinar, Lane & Thomas, 1976
* ''
Quadrimermis
''Quadrimermis'' is a genus of nematodes belonging to the family Mermithidae.
Species:
* ''Quadrimermis coramnica'' Coman, 1961
* ''Quadrimermis lovatensis'' Rubzov, 1979
* ''Quadrimermis pikkjarvensis'' Rubzov, 1979
* ''Quadrimermis vyrtsj ...
''
Coman, 1961
* ''
Reesimermis
''Reesimermis'' is a genus of nematodes belonging to the family Mermithidae.
Species:
* ''Reesimermis jacutensis'' Rubzov, 1979
* ''Reesimermis nielseni'' Tsai & Grundman, 1969
* ''Reesimermis pikaninensis
''Reesimermis'' is a genus of nema ...
''
Tsai & Grundman, 1969
* ''
Romanomermis''
* ''
Spiculimermis
''Spiculimermis'' is a genus of nematodes belonging to the family Mermithidae.
Species:
* ''Spiculimermis acaudata'' Rubzov, 1976
* ''Spiculimermis angusta
''Spiculimermis'' is a genus of nematodes belonging to the family Mermithidae.
Spe ...
''
Artyukhovskii, 1963
* ''
Strelkovimermis
''Strelkovimermis'' is a genus of nematodes belonging to the family Mermithidae.
Species:
* '' Strelkovimermis acuticauda'' Johnson & Kleve, 1996
* '' Strelkovimermis amphidis'' Johnson & Kleve, 2000
References
Mermithidae
Enoplea gen ...
''
Rubzov, 1969
* ''
Tetramermis
''Tetramermis'' is a genus of nematodes belonging to the family Mermithidae.
Species:
* '' Tetramermis lacustris'' Rubzov, 1978
* '' Tetramermis tenuis'' (Leidy, 1878)
* '' Tetramermis ventrosoma'' Rubzov, 1978
References
Mermithidae
...
''
Steiner, 1925
References
External links
*
Biological control potential* https://web.archive.org/web/20081214081804/http://flnem.ifas.ufl.edu/HISTORY/entomophilic_history.htm
* https://web.archive.org/web/20091014110925/http://www.uel.ac.uk/mosquito/issue10/mermithids.htm
on the
UF /
IFAS IFAS may refer:
* Institute of Food and Agricultural Sciences
* Integrated Fixed-Film Activated Sludge, a sewage treatment process
* International French adjectival system
In rock climbing, mountaineering, and other climbing disciplines, clim ...
Featured Creatures Web site
{{Taxonbar, from=Q150697
Parasitic nematodes of animals
Mind-altering parasites
Nematode families
Endoparasites