''Ranatra'' is a
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...
of slender
predator
Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill th ...
y insects of the family
Nepidae
Nepidae is a family of exclusively aquatic Heteropteran insects in the order Hemiptera. They are commonly called water scorpions for their superficial resemblance to scorpions, due to their raptorial forelegs and the presence of a long slender p ...
, known as water scorpions or water stick-insects. There are around 100 ''Ranatra'' species found in freshwater habitats around the world, both in warm and temperate regions, with the highest diversity in South America (almost 50 species) and Asia (about 30 species, reviewed in 1972
[Lansbury I (1972) A review of the Oriental species of ''Ranatra'' Fabricius (Hemiptera-Heteroptera: Nepidae). ''Transactions of the Royal Entomological Society of London'', vol. 124, no. 3. 287-341.]). Fewer are found elsewhere, but include several African, some in North America, three from Australia and three from the
Palearctic, notably the relatively well-known European ''
R. linearis''.
Since ''Ranatra'' belongs to the family Nepidae which in turn belongs to the order
Hemiptera, ranatrids are considered "true bugs".
These brown insects are primarily found in stagnant or slow-moving water like ponds, marshes and canals, but can also be seen in streams.
[ Exceptionally they have been recorded from ]hypersaline lake
A hypersaline lake is a landlocked body of water that contains significant concentrations of sodium chloride, brines, and other salts, with saline levels surpassing that of ocean water (3.5%, i.e. ).
Specific microbial species can thrive in hi ...
s and brackish
Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estu ...
lagoons.
Biology
The front legs of bugs in ''Ranatra'' are strong and used to grasp prey. They typically eat other insects, tadpole
A tadpole is the larval stage in the biological life cycle of an amphibian. Most tadpoles are fully aquatic, though some species of amphibians have tadpoles that are terrestrial. Tadpoles have some fish-like features that may not be found ...
s and small fish, which they pierce with their proboscis
A proboscis () is an elongated appendage from the head of an animal, either a vertebrate or an invertebrate. In invertebrates, the term usually refers to tubular mouthparts used for feeding and sucking. In vertebrates, a proboscis is an elong ...
and inject a saliva which both sedates and begins to digest their prey. They are sit-and-wait predator
Ambush predators or sit-and-wait predators are carnivorous animals that capture or trap prey via stealth, luring or by (typically instinctive) strategies utilizing an element of surprise. Unlike pursuit predators, who chase to capture prey ...
s that reside among water plants and position themselves head-down with their grasping legs extended out to surprise passing prey.[ At least one species will also swim in open water at night to catch ]zooplankton
Zooplankton are the animal component of the planktonic community ("zoo" comes from the Greek word for ''animal''). Plankton are aquatic organisms that are unable to swim effectively against currents, and consequently drift or are carried along by ...
ic organisms. Like other members in the family they have a long tail-like siphon, or breathing tube, on the rear end of their body.[ The adult body length is generally depending on the exact species, and females average larger than males of the same species. The siphon is typically almost the same size, but varies from less than half the body length to somewhat longer. Two of the largest species are the East Asian ''R. chinensis'' and South American ''R. magna''.] ''Ranatra'' do have wings and they can fly.[
The adults are active year-round, except in extreme cold. Their eggs are positioned on plants just below the water surface, but in some species they can be placed in mud.][ The eggs typically take two to four weeks to hatch and the young take about two months to mature.
RanatraLinearisHead.JPG, ''Ranatra linearis''
Ranatra chinensis.svg, ''Ranatra chinensis''
Water Scorpion - Ranatra species, Merrimac Farm Wildlife Management Area, Aden, Virginia.jpg, ''Ranatra'' crawling on human fingers
Among the four genera in the ]Ranatrinae
Nepidae is a family of exclusively aquatic Heteropteran insects in the order Hemiptera. They are commonly called water scorpions for their superficial resemblance to scorpions, due to their raptorial forelegs and the presence of a long slender p ...
subfamily, '' Austronepa'' and '' Goondnomdanepa'' are restricted to Australia. ''Cercotmetus
''Cercotmetus'' is a genus of water bugs in the subfamily Ranatrinae ("water stick-insects"). The recorded distribution of this genus is from is from mainland Asia to New Guinea and northern Australia.
Description
''Cercotmetus'' species are ...
'' from Asia to New Guinea resembles ''Ranatra'', although the former has a distinctly shorter siphon.[
]
Species
The Global Biodiversity Information Facility
The Global Biodiversity Information Facility (GBIF) is an international organisation that focuses on making scientific data on biodiversity available via the Internet using web services. The data are provided by many institutions from around the ...
lists:[Global Biodiversity Information Facility: ''Ranatra'' Fabricius, 1790 (retrieved 12 January 2021)]
/ref>
* '' Ranatra absona'' Drake & De Carlo, 1953
* '' Ranatra acapulcana'' Drake & De Carlo, 1953
* '' Ranatra adelmorpha'' Nieser, 1975
* '' Ranatra aethiopica'' Montandon, 1903
* '' Ranatra akoitachta'' Nieser, 1996
* '' Ranatra ameghinoi'' De Carlo, 1970
* '' Ranatra annulipes'' Stål, 1854
* '' Ranatra attenuata'' Kuitert, 1949
* '' Ranatra australis'' Hungerford, 1922 i c g b (southern water scorpion)
* '' Ranatra bachmanni'' De Carlo, 1954
* '' Ranatra bilobata'' Tran & Nguyen, 2016
* '' Ranatra biroi'' Lundblad, 1933
* '' Ranatra bottegoi'' Montandon, 1903
* '' Ranatra brasiliensis'' De Carlo, 1946
* '' Ranatra brevicauda'' Montandon, 1905
* '' Ranatra brevicollis'' Montandon, 1910 i c g b
* '' Ranatra buenoi'' Hungerford, 1922 i c g b
* '' Ranatra camposi'' Montandon, 1907
* '' Ranatra capensis'' Germar, 1837
* '' Ranatra cardamomensis'' Zettel, Phauk, Kheam & Freitag, 2017
* '' Ranatra chagasi'' De Carlo, 1946
* '' Ranatra chariensis'' Poisson, 1949
* ''Ranatra chinensis
''Ranatra'' is a genus of slender predatory insects of the family Nepidae, known as water scorpions or water stick-insects. There are around 100 ''Ranatra'' species found in freshwater habitats around the world, both in warm and temperate regions ...
'' Mayr, 1865
* '' Ranatra cinnamomea'' Distant, 1904
* '' Ranatra compressicollis'' Montandon, 1898
* '' Ranatra costalimai'' De Carlo, 1954
* '' Ranatra cruzi'' De Carlo, 1950
* '' Ranatra curtafemorata'' Kuitert, 1949
* '' Ranatra denticulipes'' Montandon, 1907
* '' Ranatra digitata'' Hafiz & Pradhan, 1949
* '' Ranatra diminuta'' Montandon, 1907
* '' Ranatra dispar'' Montandon, 1903
* '' Ranatra distanti'' Montandon, 1910
* '' Ranatra doesburgi'' De Carlo, 1963
* '' Ranatra dolichodentata'' Kuitert, 1949
* '' Ranatra dormientis'' Zhang et al., 1994
* '' Ranatra drakei'' Hungerford, 1922
* '' Ranatra ecuadoriensis'' De Carlo, 1950
* '' Ranatra elongata'' Fabricius, 1790
* '' Ranatra emaciata'' Montandon, 1907
* '' Ranatra fabricii'' Guérin-Méneville, 1857
* '' Ranatra falloui'' Montandon, 1907
* '' Ranatra feana'' Montandon, 1903
* '' Ranatra fianarantsoana'' Poisson, 1963
* '' Ranatra filiformis'' Fabricius, 1790
* '' Ranatra flagellata'' Lansbury, 1972
* '' Ranatra flokata'' Nieser & Burmeister, 1998
* '' Ranatra fusca'' Palisot, 1820 i c g b (brown waterscorpion)
* '' Ranatra fuscoannulata'' Distant, 1904
* '' Ranatra galantae'' Nieser, 1969
* '' Ranatra gracilis'' Dallas, 1850
* '' Ranatra grandicollis'' Montandon, 1907
* '' Ranatra grandocula'' Bergroth, 1893
* '' Ranatra hechti'' De Carlo, 1967
* '' Ranatra heoki'' Tran & Poggi, 2019
* '' Ranatra heydeni'' Montandon, 1909
* '' Ranatra horvathi'' Montandon, 1910
* '' Ranatra hungerfordi'' Kuitert, 1949
* '' Ranatra incisa'' Chen, Nieser & Ho, 2004
* '' Ranatra instaurata'' Montandon, 1914
* '' Ranatra insulata'' Barber, 1939
* '' Ranatra jamaicana'' Drake & De Carlo, 1953
* '' Ranatra katsara'' Nieser, 1997
* '' Ranatra kirkaldyi'' Torre-bueno, 1905 i c g b
* '' Ranatra lanei'' De Carlo, 1946
* '' Ranatra lansburyi'' Chen, Nieser & Ho, 2004
* '' Ranatra lenti'' De Carlo, 1950
* '' Ranatra lethierryi'' Montandon, 1907
* '' Ranatra libera'' Zettel, 1999
* '' Ranatra linearis'' (Linnaeus, 1758) i c g
* '' Ranatra longipes'' Stål, 1861
* '' Ranatra lualalai'' Poisson, 1964
* '' Ranatra lubwae'' Poisson, 1965
* '' Ranatra machrisi'' Nieser & Burmeister, 1998
* '' Ranatra macrophthalma'' Herrich-Schäffer, 1849
* '' Ranatra maculosa'' Kuitert, 1949
* '' Ranatra magna'' Kuitert, 1949
* '' Ranatra malayana'' Lundblad, 1933
* '' Ranatra mediana'' Montandon, 1910
* '' Ranatra megalops'' Lansbury, 1972
* '' Ranatra mixta'' Montandon, 1907
* '' Ranatra moderata'' Kuitert, 1949
* '' Ranatra montei'' De Carlo, 1946
* '' Ranatra montezuma'' Polhemus, 1976
* '' Ranatra natalensis'' Distant, 1904
* '' Ranatra natunaensis'' Lansbury, 1972
* '' Ranatra neivai'' De Carlo, 1946
* '' Ranatra nieseri'' Tran & Nguyen, 2016
* '' Ranatra nigra'' Herrich-Schaeffer, 1849
* '' Ranatra nodiceps'' Gerstaecker, 1873
* '' Ranatra nodioeps'' Gerstaecker, 1873
* '' Ranatra obscura'' Montandon, 1907
* '' Ranatra occidentalis'' Lansbury, 1972
* '' Ranatra odontomeros'' Nieser, 1996
* '' Ranatra oliveiracesari'' De Carlo, 1946
* '' Ranatra operculata'' Kuitert, 1949
* '' Ranatra ornitheia'' Nieser, 1975
* '' Ranatra parmata'' Mayr, 1865
* '' Ranatra parvipes'' Signoret, 1861
* '' Ranatra parvula'' Kuitert, 1949
* '' Ranatra pittieri'' Montandon, 1910
* '' Ranatra protense'' Montandon
* '' Ranatra quadridentata'' Stål, 1862 i c g b
* '' Ranatra rabida'' Buchanan White, 1879
* '' Ranatra rafflesi'' Tran & D.Polhemus, 2012
* '' Ranatra rapax'' Stål, 1865
* '' Ranatra recta'' Chen, Nieser & Ho, 2004
* '' Ranatra robusta'' Montandon, 1905
* '' Ranatra sagrai'' Drake & De Carlo, 1953
* '' Ranatra sarmientoi'' De Carlo, 1967
* '' Ranatra sattleri'' De Carlo, 1967
* '' Ranatra schuhi'' D.Polhemus & J.Polhemus, 2012
* '' Ranatra segrega'' Montandon, 1913
* '' Ranatra signoreti'' Montandon, 1905
* '' Ranatra similis'' Drake & De Carlo, 1953
* '' Ranatra siolii'' De Carlo, 1970
* '' Ranatra sjostedti'' Montandon, 1911
* '' Ranatra spatulata'' Kuitert, 1949
* '' Ranatra spinifrons'' Montandon, 1905
* '' Ranatra spoliata'' Montandon, 1912
* '' Ranatra stali'' Montandon, 1905
* '' Ranatra sterea'' Chen, Nieser & Ho, 2004
* '' Ranatra subinermis'' Montandon, 1907
* '' Ranatra sulawesii'' Nieser & Chen, 1991
* '' Ranatra surinamensis'' De Carlo, 1963
* '' Ranatra texana'' Hungerford, 1930
* '' Ranatra thai'' Lansbury, 1972
* '' Ranatra titilaensis'' Hafiz & Pradhan, 1949
* '' Ranatra travassosi'' De Carlo, 1950
* '' Ranatra tridentata'' Poisson, 1965
* '' Ranatra tuberculifrons'' Montandon, 1907
* '' Ranatra unicolor'' Scott, 1874
* '' Ranatra unidentata'' Stål, 1861
* '' Ranatra usingeri'' De Carlo, 1970
* '' Ranatra varicolor'' Distant, 1904
* '' Ranatra varipes'' Stål, 1861
* '' Ranatra vitshumbii'' Poisson, 1949
* '' Ranatra wagneri'' Hungerford, 1929
* '' Ranatra weberi'' De Carlo, 1970
* '' Ranatra williamsi'' Kuitert, 1949
* '' Ranatra zeteki'' Drake & De Carlo, 1953
Data sources: i = ITIS,[ c = Catalogue of Life,][ g = GBIF,][ b = Bugguide.net]
References
External links
*
*
{{Taxonbar, from=Q1154489
Nepidae
Nepomorpha genera