Water treaders, the

superfamily SUPERFAMILY is a database and search platform of structural and functional annotation for all proteins and genomes. It classifies amino acid sequences into known structural domains, especially into SCOP superfamilies. Domains are functional, str ...

Mesovelioidea, are

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pairs ...

s in the order

Hemiptera Hemiptera (; ) is an order (biology), order of insects, commonly called true bugs, comprising over 80,000 species within groups such as the cicadas, aphids, planthoppers, leafhoppers, Reduviidae, assassin bugs, Cimex, bed bugs, and shield bugs. ...

, the true bugs. They are semiaquatic insects that live in moist and wet habitat and on wet plant matter in several types of aquatic habitat.Yang, C. M. and D. H. Murphy. (2011)
Guide to the aquatic Heteroptera of Singapore and peninsular Malaysia. 6. Mesoveliidae, with description of a new ''Nereivelia'' species from Singapore.
''Raffles Bulletin of Zoology'' 59, 53-60. These insects are no more than 3.5 mm long. They have elongated heads, long antennae, and large eyes, with the exception of ''Cryptovelia'' species, which have

vestigial Vestigiality is the retention, during the process of evolution, of genetically determined structures or attributes that have lost some or all of the ancestral function in a given species. Assessment of the vestigiality must generally rely on co ...

eyes. Females are larger than the males of their species and have well-developed

ovipositor The ovipositor is a tube-like organ used by some animals, especially insects, for the laying of eggs. In insects, an ovipositor consists of a maximum of three pairs of appendages. The details and morphology of the ovipositor vary, but typical ...

s. The

type genus In biological taxonomy, the type genus is the genus which defines a biological family and the root of the family name. Zoological nomenclature According to the International Code of Zoological Nomenclature, "The name-bearing type of a nominal f ...

, '' Mesovelia'', contains about 27 species, many of which are common and widespread.Andersen, N. M. and D. A. Polhemus. (2003)
A new genus of terrestrial Mesovellidae from the Seychelles (Hemiptera: Gerromorpha).
''Journal of the New York Entomological Society'' (111), 12-21. The other genera are small or even

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...

, and are less common. One species is known for its unique specific name, ''

Cavaticovelia aaa ''Cavaticovelia'' is a monotypic genus of insects in the order Hemiptera, the true bugs, containing the single species ''Cavaticovelia aaa''. This bug, known commonly as the aaa water treader or lava tube water treader, is a water treader native ...

'', sometimes called the aaa water treader. It is a legitimate binomial name following the

International Code of Zoological Nomenclature The International Code of Zoological Nomenclature (ICZN) is a widely accepted convention in zoology that rules the formal scientific naming of organisms treated as animals. It is also informally known as the ICZN Code, for its publisher, the ...

, featuring ''aaa'', the Hawaiian word for "

lava tube A lava tube, or pyroduct, is a natural conduit formed by flowing lava from a volcanic vent that moves beneath the hardened surface of a lava flow. If lava in the tube empties, it will leave a cave. Formation A lava tube is a type of lava ca ...

". According to some treatments, two families are in the Mesovelioidea. In others, the family Madeoveliidae is treated as a subfamily of the Mesoveliidae.Damgaard, J., et al. (2012)
Molecular phylogeny of the pond treaders (Insecta: Hemiptera: Heteroptera: Mesoveliidae), discussion of the fossil record and a checklist of species assigned to the family.
''Insect Systematics & Evolution'' 43(3-4), 175-212. The two families, separated, with included genera are: * Madeoveliidae ** '' Madeovelia'' Poisson, 1959 ** '' Mesoveloidea'' Hungerford, 1929 *

Mesoveliidae Mesoveliidae is a family of water treaders in the order Hemiptera. There are about 16 genera and at least 50 described species in Mesoveliidae. Genera These 12 extant genera belong to the family Mesoveliidae: * '' Austrovelia'' Malipatil and Mo ...

– water treaders, pondweed bugs ** '' Austrovelia'' ** '' Cavaticovelia'' ** '' Cryptovelia'' Andersen & Polhemus, 1980 ** '' Darwinivelia'' Andersen & Polhemus, 1980 ** '' Mesovelia'' Mulsant and Rey, 1852 ** '' Mniovelia'' Andersen & Polhemus, 1980 ** '' Nereivelia'' ** '' Phrynovelia'' Horváth, 1915 ** '' Seychellovelia'' Andersen & Polhemus, 2003 ** '' Speovelia'' Esaki, 1929

References

{{Gerromorpha-stub