Ancylometes
Encyclopedia
Ancylometes is a fishing spider
genus from South America
, where they live near ponds and small lakes. The spiderlings can walk over water rather fast, in a fashion similar to water strider
s. This is because of fine air-trapping hairs on the tips of their legs. They can dive underwater, and will consume anything from insects to small lizards and fish. They can stay underwater for over an hour, using air trapped in hairs surrounding their book lung
s as a physical gill. Ancylometes is one of only two known spiders that can spin webs in water and they do sometimes catch fish. However, they mostly catch fish by diving down or lying in wait until prey passes within striking distance. They do however consume them on the ground or above the water.
A. rufus females have a body length of up to 5 cm (12 cm leg span), while males grow to up to 3 cm, but with longer legs. Both sexes are brown with dark spots on the abdomen
, with two thin lines along the carapace
of the male.
The male immobilizes the female with silk during mating, while the female enters an immobile state by itself. The female produces a cocoon after about a week, which is carried with the fangs. After a month, the female builds a nursery web above the ground which is about 10 cm in diameter. More than 100 spiderlings (each about 2 mm long) hatch inside the egg case. A spiderling takes about a year to mature. Males die after at the most 16 months, while females can live for more than two years.
Until 1967, the genus was considered to belong to the family Pisauridae, but was then moved to the family Ctenidae.
The genus name is derived in part from Greek ancylo-, meaning "crooked, bent".
Spider
Spiders are air-breathing arthropods that have eight legs, and chelicerae with fangs that inject venom. They are the largest order of arachnids and rank seventh in total species diversity among all other groups of organisms...
genus from South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
, where they live near ponds and small lakes. The spiderlings can walk over water rather fast, in a fashion similar to water strider
Water strider
Gerridae is a family of true bugs in the order Hemiptera, commonly known as water striders, water bugs, magic bugs, pond skaters, skaters, skimmers, water scooters, water skaters, water skeeters, water skimmers, water skippers, water spiders, or Jesus bugs...
s. This is because of fine air-trapping hairs on the tips of their legs. They can dive underwater, and will consume anything from insects to small lizards and fish. They can stay underwater for over an hour, using air trapped in hairs surrounding their book lung
Book lung
A book lung is a type of respiration organ used for atmospheric gas exchange and is found in arachnids, such as scorpions and spiders. Each of these organs is found inside a ventral abdominal cavity and connects with the surroundings through a small opening. Book lungs are not related to the lungs...
s as a physical gill. Ancylometes is one of only two known spiders that can spin webs in water and they do sometimes catch fish. However, they mostly catch fish by diving down or lying in wait until prey passes within striking distance. They do however consume them on the ground or above the water.
A. rufus females have a body length of up to 5 cm (12 cm leg span), while males grow to up to 3 cm, but with longer legs. Both sexes are brown with dark spots on the abdomen
Abdomen
In vertebrates such as mammals the abdomen constitutes the part of the body between the thorax and pelvis. The region enclosed by the abdomen is termed the abdominal cavity...
, with two thin lines along the carapace
Carapace
A carapace is a dorsal 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 tortoises, the underside is called the plastron.-Crustaceans:In crustaceans, the...
of the male.
The male immobilizes the female with silk during mating, while the female enters an immobile state by itself. The female produces a cocoon after about a week, which is carried with the fangs. After a month, the female builds a nursery web above the ground which is about 10 cm in diameter. More than 100 spiderlings (each about 2 mm long) hatch inside the egg case. A spiderling takes about a year to mature. Males die after at the most 16 months, while females can live for more than two years.
Until 1967, the genus was considered to belong to the family Pisauridae, but was then moved to the family Ctenidae.
The genus name is derived in part from Greek ancylo-, meaning "crooked, bent".
Species
- Ancylometes amazonicus Simon, 1898 (Peru, Brazil)
- Ancylometes birabeni (Carcavallo & Martínez, 1961) (Argentina)
- Ancylometes bogotensis (Keyserling, 1877) (Nicaragua to Bolivia)
- Ancylometes concolor (Perty, 1833) (Brazil, Bolivia, Paraguay, Argentina)
- Ancylometes hewitsoni (F. O. P.-Cambridge, 1897) (Bolivia, Brazil)
- Ancylometes japura Höfer & Brescovit, 2000 (Brazil)
- Ancylometes jau 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)
Further reading
- Gasnier, T.R., Salette de Azevedo, C., Torres-Sanchez, M.P. & Höfer, H. (2002). Adult size of eight hunting spider species in Central Amazonia: Temporal variations and sexual dimorphisms. Journal of Arachnology 30:146-154. PDF
- Walking on the water
- Merrett, P. (1988). Notes on the biology of the neotropical pisaurid, Ancylometes bogotensis (Keyserling) (Araneae: Pisauridae). Bull. Br. arachnol. Soc. 7:197-201.