''Ancylometes'' 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 ...

Central Central is an adjective usually referring to being in the center of some place or (mathematical) object. Central may also refer to: Directions and generalised locations * Central Africa, a region in the centre of Africa continent, also known as ...

and

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...

n semiaquatic wandering spiders first described by Philipp Bertkau in 1880. Originally placed with the nursery web spiders, it was moved to the Ctenidae in 1967. The genus name is derived in part from

Ancient Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic peri ...

"" ('' ancylo-''), meaning "crooked, bent". These spiders live near ponds, lakes, rivers and other freshwater habitats, and can walk on water like water striders due to fine air-trapping hairs on the tips of their legs. They can also dive under the surface, and can stay underwater for over an hour by using the air trapped in hairs surrounding their

book lung A book lung is a type of respiration organ used for atmospheric gas exchange that is present in many arachnids, such as scorpions and spiders. Each of these organs is located inside an open ventral abdominal, air-filled cavity (atrium) and conn ...

s. They will consume anything from insects to small lizards and, occasionally, small fish.

Description

Members of ''Ancylometes'' are among the largest araneomorph spiders, with a typical body length of . They are sometimes referred to as "giant fishing spiders" to distinguish them from '' Dolomedes'', a genus of smaller spiders also called "fishing spiders". The largest species is ''A. rufus'', with females that grow to a body length of and a leg span of . Males of the species only grow up to in body length, but usually have longer legs than the females. Both sexes are brown with dark spots on the

abdomen The abdomen (colloquially called the belly, tummy, midriff, tucky or stomach) is the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the front part of the abdominal segment of the torso. ...

, and males have two thin lines along their

carapace A carapace is a Dorsum (biology), dorsal (upper) section of the exoskeleton or shell in a number of animal groups, including arthropods, such as crustaceans and arachnids, as well as vertebrates, such as turtles and tortoises. In turtles and tor ...

. They have a 2-4-2 eye pattern and a reduced third claw, characteristics of the Ctenidae and Pisauridae, respectively. Members of this genus can be distinguished from all others by ventral spines found on the tarsi of the third and fourth legs. ''Ancylometes'' and the more fully aquatic '' Argyroneta'' are the only known genera of spiders that can spin webs in water. Though these webs can catch fish, they mostly prey on fish by diving down or lying in wait until prey passes within striking distance. Once caught, these spiders will bring their prey back to the surface before eating it. During mating, the male wraps the female with silk, and the female enters an immobile state. After about a week, she produces a cocoon and carries it with her fangs. After a month, she builds a nursery web above the ground, about in diameter. Over one hundred baby spiders will hatch inside this egg case, each only about long. The baby spiders take about a year to mature. Males only live for sixteen months at most, while females can live for more than two years. The venom of Acyclomete sp, has effects on muscle contraction and preparation of the phrenic nerve diaphragm muscle, 50 µg causes depolarization of the diaphragm muscle fiber membranes. These studies indicate that the Ancylometes venom activates

voltage-gated sodium channels Sodium channels are integral membrane proteins that form ion channels, conducting sodium ions (Na+) through a cell's membrane. They belong to the superfamily of cation channels and can be classified according to the trigger that opens the channel ...

. All of these effects of Ancylometes sp. venom on this nerve muscle preparation increase in twitch tension.

Species

it contains eleven species: *''

Ancylometes amazonicus ''Ancylometes'' is a genus of Central and South American semiaquatic wandering spiders first described by Philipp Bertkau in 1880. Originally placed with the nursery web spiders, it was moved to the Ctenidae in 1967. The genus name is derived ...

'' Simon, 1898 – Peru, Brazil *''

Ancylometes birabeni ''Ancylometes'' is a genus of Central and South American semiaquatic wandering spiders first described by Philipp Bertkau in 1880. Originally placed with the nursery web spiders, it was moved to the Ctenidae in 1967. The genus name is derived ...

'' (Carcavallo & Martínez, 1961) – Argentina *''

Ancylometes bogotensis ''Ancylometes'' is a genus of Central and South American semiaquatic wandering spiders first described by Philipp Bertkau in 1880. Originally placed with the nursery web spiders, it was moved to the Ctenidae in 1967. The genus name is derived ...

'' ( Keyserling, 1877) – Honduras to Bolivia *''

Ancylometes concolor ''Ancylometes'' is a genus of Central and South American semiaquatic wandering spiders first described by Philipp Bertkau in 1880. Originally placed with the nursery web spiders, it was moved to the Ctenidae in 1967. The genus name is derived ...

'' (Perty, 1833) ( type) – Brazil, Bolivia, Paraguay, Argentina *''

Ancylometes hewitsoni ''Ancylometes'' is a genus of Central and South American semiaquatic wandering spiders first described by Philipp Bertkau in 1880. Originally placed with the nursery web spiders, it was moved to the Ctenidae in 1967. The genus name is derived ...

'' ( F. O. Pickard-Cambridge, 1897) – Bolivia, Brazil *''

Ancylometes japura ''Ancylometes'' is a genus of Central and South American semiaquatic wandering spiders first described by Philipp Bertkau in 1880. Originally placed with the nursery web spiders, it was moved to the Ctenidae in 1967. The genus name is derived ...

'' Höfer & Brescovit, 2000 – Brazil *''

Ancylometes jau ''Ancylometes'' is a genus of Central and South American semiaquatic wandering spiders first described by Philipp Bertkau in 1880. Originally placed with the nursery web spiders, it was moved to the Ctenidae in 1967. The genus name is derive ...

'' Höfer & Brescovit, 2000 – Brazil *'' Ancylometes pantanal'' Höfer & Brescovit, 2000 – Brazil *'' Ancylometes riparius'' Höfer & Brescovit, 2000 – Brazil *'' Ancylometes rufus'' ( Walckenaer, 1837) – Northern South America *'' Ancylometes terrenus'' Höfer & Brescovit, 2000 – Brazil

References

External links

Website especially for the Genus ''Ancylometes'': www.ancylometes.com
{{Taxonbar, from=Q2846015 Ctenidae Spiders of South America Araneomorphae genera

Description

Species

References

Further reading

External links