''Arrenurus'' (αρρεν - male, ουρά - tail) is a genus of water mites within the family

Arrenuridae Arrenuridae is a family of prostigs in the order Trombidiformes The Trombidiformes are a large, diverse order of mites. Taxonomy In 1998, Trombidiformes was divided into the Sphaerolichida and the Prostigmata. The group has few synapomorphi ...

, and was first described by

Antoine Louis Dugès Antoine Louis Dugès (19 December 1797 – 1 May 1838) was a French obstetrician and naturalist born in Charleville-Mézières, Ardennes. He was the father of zoologist Alfredo Dugès (1826–1910), and a nephew to midwife Marie-Louise Lachape ...

in 1834. It has a cosmopolitan distribution in lentic waters, even on remote Pacific islands, and is found on every continent, with the possible exception of

Antarctica Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest contine ...

. Some 950 species are currently recognised, making ''Arrenurus'' the largest of genera. ''Arrenurus'' goes through seven stages - egg, inactive prelarva, larva, protonymph,

deutonymph Mites are small arachnids (eight-legged arthropods). Mites span two large orders of arachnids, the Acariformes and the Parasitiformes, which were historically grouped together in the subclass Acari, but genetic analysis does not show clear evid ...

, tritonymph, and adult, only the larval stage being parasitic, and marked sexual dimorphism in the heavily sclerotised adults. Taxonomy of females is often problematic, but relatively simple in the males. ''Arrenurus'' larvae are ectoparasites of some aquatic insects in freshwater habitats, particularly the Odonata (Dragonflies and Damselflies). These mites establish an association for the purpose of transportation and nutrients, and attach to the host during the host's transition from larva to adult. Andrew et al. 2012, found that it is mainly ''Arrenurus'' species that are to be found on Odonata. Studies also show that parasitism by the mites affect the host's longevity and fecundity by draining its tissue fluids, hampering copulation and interfering with sperm transfer. ''Arrenurus'' larvae are also ectoparasites of

Diptera Flies are insects of the order Diptera, the name being derived from the Greek δι- ''di-'' "two", and πτερόν ''pteron'' "wing". Insects of this order use only a single pair of wings to fly, the hindwings having evolved into advanced ...

and

Coleoptera Beetles are insects that form the order Coleoptera (), in the superorder Endopterygota. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 400,000 describ ...

. After the odonatid has left the water and shed its skin, mites move from the exuviae onto the still soft adult. They often select the ventral parts of the thorax or abdomen, and to a lesser extent are found on the back or on the head, or on the major wing veins. After penetrating the dermis of the host, the larval mite produces a

stylostome The stylostome is a funnel- or channel-like structure formed in response to trombiculid mites. The formation is not caused by the mouthparts of the mites, because these mites do not have needle-like mouthparts as other hematophagous animals have ...

, or small blind sac, within the host's body. Most stylostomes are able to resist assault by the host's immune system, such action consisting of initial hemolymph clotting, and deposition of

melanin Melanin (; from el, μέλας, melas, black, dark) is a broad term for a group of natural pigments found in most organisms. Eumelanin is produced through a multistage chemical process known as melanogenesis, where the oxidation of the amino ...

around the sac and its encapsulation. Feeding from the host is only one of the aims - the other is

phoresy Phoresis or phoresy is a non-permanent, Commensalism, commensalistic interaction in which one organism (a phoront or phoretic) attaches itself to another (the host) solely for the purpose of travel. Phoresis has been observed directly in Acari ...

or using the host for transportation. Many mites are phoretic - the benefits being dispersal, fresh habitat, and expanding the

gene pool The gene pool is the set of all genes, or genetic information, in any population, usually of a particular species. Description A large gene pool indicates extensive genetic diversity, which is associated with robust populations that can surv ...

References

External links

''Recherches sur l'ordre des Acariens en général et la famille des Trombidiés en particular''
* ''Dragonflies: Behavior and Ecology of Odonata'' - Philip Corbet (1999) {{Taxonbar, from=Q4625192 Arrenuridae Chelicerate genera