Leucorchestris arenicola | |
---|---|
White lady spider in Namibia | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Subphylum: | Chelicerata |
Class: | Arachnida |
Order: | Araneae |
Infraorder: | Araneomorphae |
Family: | Sparassidae |
Genus: | Leucorchestris |
Species: | L. arenicola |
Binomial name | |
Leucorchestris arenicola Lawrence, 1962 | |
Synonyms | |
|
Leucorchestris arenicola, commonly called the dancing white lady spider, is a huntsman spider in the family Sparassidae and genus Leucorchestris. It is commonly found in the Namib desert of Namibia. It is often mistaken with the similarly named Carparachne aureoflava, or more commonly known as the wheel spider from the same location. [1] [2] L. arenicola relies on seismic vibrations, called drumming, for communication. It taps its foremost legs on the sand to send messages to other white lady spiders. Male L. arenicola will travel over 50 m in one night searching for a mate. If they find a mate, they must be extremely careful, for drumming the wrong message can be deadly. [1] One of the major features that characterizes its nocturnal behavior is its specialized vision, using eight eyes in different orientations to capture a panoramic view of the surroundings. L. arenicola spiders use temporal summation in order to be able to see dim lighting during night-time wanderings. [3] The species was first described by Reginald Frederick Lawrence in 1962, who described all the species in the genus Leucorchestris . [2]
L. arenicola have a creamy, white shading. Their bodies can be up to 32 mm (1.3 in) long. Males may have leg spans up to 14 cm (5.5 in). Males differ from females in that they are lighter in weight with longer leg spans. [4]
Leg spination is the most reliable way to differentiate between sexes among L. arenicola. [4] Between 5 and 8 legs of males contain a median tibia dorsal spine. When this feature is found in females, it will only be seen on a maximum of 4 legs. However, females will rarely have this spine. Other characteristics, including eye arrangement, pedipalp structure, tibial claws, and prosoma dimensions, do not predict differences in sex. [4]
L. arenicola are found primarily in desert regions of Namibia, particularly the dunes of the Namib Desert. The spiders reside in burrows with a territory that extend across an approximate 3 meter radius within bare dunes of the region. As exclusively nocturnal creatures, L. arenicola spiders remain hidden in their burrows to protect themselves from the heat of the desert sun. [5]
L. arenicola stay within their burrows throughout the day and then wander beyond their territory radius at night. Burrows are dug into the sand and are lined with silk. [5] The burrows may be up to 40 cm long, 25 cm deep, and at about a 30 degree angle. The specificity of the burrow's dimensions create cooler temperatures in which the spiders preferentially reside. [4] Silk may also be used to hold loose sand in place. The burrow wall is stabilized using long spigots on their long spinnerets to interweave the sand as far as 3 millimeters deep. [6] The burrows are usually occupied for a couple of months. Burrows are sometimes covered by a camouflaged covering. [7]
L. arenicola are considered polyphagous since they can feed on a large variety of foods that remain constant across seasons. This can vary from insects, to arachnids, and reptiles. L. arenicola prey on over 97 species within these categories. [8] The majority of the prey are also nocturnal organisms and consist of beetles, moths, and weevils. However, this depends on the region and territory occupied by the spider, based on the surrounding fauna. [8]
Foraging usually occurs within a 3 m radius of the burrow, and rarely occurs during night wanderings beyond this radius. L. arenicola forage for food for several nights, followed by a period of rest. Most of the prey captured are two-thirds the size of the spider or smaller, but every few weeks, L. arenicola capture larger prey that can be greater than 3 mm. [9] The foraging strategy used by L. arenicola is a sit-and-wait strategy, whereby they sit idly within their territory and wait until prey arrive. Some L. arenicola, especially the larger males, engage in cannibalism. This is often due to increased competition and food shortages in their territory. [8]
L. arenicola engage in reproductive patterns with consistent incubation periods of 15 days. This seasonality of reproduction is largely due to the male spiders, who spend the winter months molting to adulthood, while female spiders are present year-round. This is evidenced by the reduction in eggs found during winter months. Egg clutches are enclosed in a 5 mm thick cocoon, hidden about 12 cm deep in the burrow. There are about 76 eggs on an average per clutch. Spinning the cocoon takes up a significant amount of the female spider's energy. She loses about 5 mg in weight upon completing it. [4]
L. arenicola engage in long-distance wandering late at night in pursuit of mates before returning to their burrows. Male L. arenicola venture anywhere from 16 to 91 m outside of their radius, and walk approximately 42 to 314 m within that radius. [1] During this time, males venture into female territories, mating with up to 50% of the female spiders they come across. [9] L. arenicola is a promiscuous species, engaging in mating behaviors upon encountering a spider of the opposite sex. Female and spiderling L. arenicola also wander in the dark; however, they remain within their 3 m radius. [1]
During the long-distance wandering at night, male L. arenicola sometimes disappear. This may be due to predation by gerbils and other desert species. [1] Female L. arenicole live approximately 6 months, while males live 1–2 months. [10] This can be partially attributed to the increased risk of mortality upon nocturnal wandering beyond the 3 m territory radius. Furthermore, during vibrational signaling for mating, males risk getting attacked and killed by female L. arenicola if their signal is not distinguishable enough from prey. [10]
During long-distance wandering, male L. arenicola may encounter up to five other male territories. Males compete for mates during long-distance wanderings and often display aggressive and warning signals to other males. [1] Male L. arenicola may interfere with another male in the process of mating. This applies especially for larger males. Roughly 50% of the mating behavior is dominated by 8% of the males in a region, of which all are larger in size. For males that do not differ greatly in size, they must avoid any confrontation with larger males. [9] These males will signal for other males to keep away via a sand drumming display. Drumming is seen mostly during wandering away from the burrow and has adapted as a method of signaling other adult L. arenicola of its presence, either for mating purposes or to keep away.
Male and female L. arenicola sometimes mate on successive nights. The frequency of mating is related to the male's size, with larger males tending to mate more than smaller males. Mating is limited to a small group of females. [1] Smaller females do not tend to mate as much due to reduced fecundity. When males encounter a female burrow, they use vibrational signaling through the sand to alert the female of its presence. However, the male must ensure that these seismic signals are distinguishable from those of other predators to prevent being attacked and killed by the female spider.
L. arenicola have eight eyes, with four eyes on the anterior side of the carapace and four on the posterior side. Based on their position, the eyes fall under the name anterior median eyes (AMEs), anterior lateral eyes (ALEs), posterior median eyes (PMEs), or the posterior lateral eyes (PLEs). [5] AMEs are the main eyes, while the others are considered secondary eyes. AMEs are classified as principal eyes because they have a reversed retina with muscles that have control over the direction and magnitude of the receptive field, while ALEs, PMEs, and PLEs have no muscular retinal control and an inverse retina with a reflecting tapetum behind it which aids in night vision. [5]
The visual fields of the lateral eyes (ALEs and PLEs) are elongated along a horizontal plane and overlap. This allows the spiders to have an extensive receptive field across the horizontal plane. AMEs had circular visual fields that appear to be forward looking and also overlapped, while PMEs have overlapping visual fields that integrates upper planes of sight. Together these visual fields produce a full panoramic visualization of the spider's surroundings. AMEs, PLEs, and ALEs are involved in nocturnal navigation, while PMEs are not. [5]
Although seismic communication via drumming and other vibrational mechanisms assist in navigation in the dark, vision is a major factor in nocturnal navigation. This differs from other spider species, in which vision does not play a significant role in nocturnal visualization. [3] L. arenicola have visual fields that span an entire panoramic visualization of surroundings. The spider’s eight eyes assist in this ability to visualize one’s surroundings. Each eye is enabled to specialize and fine tune its function for specific visual tasks. In the case of L. arenicola, this specialization is in navigation. Eyes are composed of one photopigment that best captures light of about 550 nm. However, they have weak temporal resolution in dark conditions. [4] In order to be able to see at night, L. arenicola use temporal summation for navigation across the dunes. [5] Temporal summation of visual stimuli allows multiple stimuli to be integrated to capture visual information in dim lighting. [3] The disadvantage to this adaptation is that quickly-moving object cannot be seen, since each temporal sum takes about 1 second. [5]
The Thomisidae are a family of spiders, including about 170 genera and over 2,100 species. The common name crab spider is often linked to species in this family, but is also applied loosely to many other families of spiders. Many members of this family are also known as flower spiders or flower crab spiders.
Wolf spiders are members of the family Lycosidae, named for their robust and agile hunting skills and excellent eyesight. They live mostly in solitude, hunt alone, and usually do not spin webs. Some are opportunistic hunters, pouncing upon prey as they find it or chasing it over short distances; others wait for passing prey in or near the mouth of a burrow. Wolf spiders resemble nursery web spiders, but wolf spiders carry their egg sacs by attaching them to their spinnerets, while the Pisauridae carry their egg sacs with their chelicerae and pedipalps. Two of the wolf spider's eight eyes are large and prominent; this distinguishes them from nursery web spiders, whose eyes are all of roughly equal size. This can also help distinguish them from the similar-looking grass spiders.
Jumping spiders are a group of spiders that constitute the family Salticidae. As of 2019, this family contained over 600 described genera and over 6,000 described species, making it the largest family of spiders at 13% of all species. Jumping spiders have some of the best vision among arthropods and use it in courtship, hunting, and navigation. Although they normally move unobtrusively and fairly slowly, most species are capable of very agile jumps, notably when hunting, but sometimes in response to sudden threats or crossing long gaps. Both their book lungs and tracheal system are well-developed, and they use both systems. Jumping spiders are generally recognized by their eye pattern. All jumping spiders have four pairs of eyes, with the anterior median pair being particularly large.
Huntsman spiders, members of the family Sparassidae, are known by this name because of their speed and mode of hunting. They are also called giant crab spiders because of their size and appearance. Larger species sometimes are referred to as wood spiders, because of their preference for woody places. In southern Africa the genus Palystes are known as rain spiders or lizard-eating spiders. Commonly, they are confused with baboon spiders from the Mygalomorphae infraorder, which are not closely related.
Heteropoda venatoria is a species of spider in the family Sparassidae, the huntsman spiders. It is native to the tropical regions of the world, and it is present in some subtropical areas as an introduced species. Its common names include giant crab spider, pantropical huntsman spider or cane spider.
Lycosa tarantula is the species originally known as the tarantula, a name that nowadays in English commonly refers to spiders in another family entirely, the Theraphosidae. It now may be better called the tarantula wolf spider, being in the wolf spider family, the Lycosidae. L. tarantula is a large species found in southern Europe, especially in the Apulia region of Italy and near the city of Taranto, from which it gets its name.
Misumena vatia is a species of crab spider with a holarctic distribution. In North America, it is called the goldenrod crab spider or flower (crab) spider, as it is commonly found hunting in goldenrod sprays and milkweed plants. They are called crab spiders because of their unique ability to walk sideways as well as forwards and backwards. Both males and females of this species progress through several molts before reaching their adult sizes, though females must molt more to reach their larger size. Females can grow up to 10 mm (0.39 in) while males are quite small, reaching 5 mm (0.20 in) at most. Misumena vatia are usually yellow or white or a pattern of these two colors. They may also present with pale green or pink instead of yellow, again, in a pattern with white. They have the ability to change between these colors based on their surroundings through the molting process. They have a complex visual system, with eight eyes, that they rely on for prey capture and for their color-changing abilities. Sometimes, if Misumena vatia consumes colored prey, the spider itself will take on that color.
Maratus volans is a species in the jumping spider family (Salticidae), belonging to the genus Maratus. These spiders are native to certain areas in Australia and occupy a wide distribution of habitats. They have a specialized visual system that allows them to see the full visible spectrum as well as in the ultraviolet-range; this helps them detect and pursue prey. Males of this species are characterized by their colourful abdomen flaps that are used to attract females during courtship.
Leucorchestris is a genus of African huntsman spiders that was first described in 1962 by R. F. Lawrence, who described all of the species in the genus between 1962 and 1966.
Onymacris unguicularis, also known commonly as the fog-basking beetle, head-stander beetle, or the Toktokkies, is a species of darkling beetle that is native to the Namib Desert of southwestern Africa. At night, during foggy weather, these beetles climb sand dunes and stand on their forelegs in order to capture water droplets as they run down their vertical bodies and into their mouths The behaviour is called "fog-basking" and is unique to Onymacris unguicularis and Onymacris bicolor.
Dolomedes minor is a spider in the family Pisauridae that is endemic to New Zealand, where it is known as the nursery web spider.
Aphonopelma chalcodes, commonly known as the western desert tarantula, desert blonde tarantula, Arizona blonde tarantula or Mexican blonde tarantula, is a species of spider belonging to the family Theraphosidae. It has a limited distribution in the deserts of Arizona and adjacent parts of Mexico but can be very common within this range. The common name "blonde tarantula" refers to the carapace, which is densely covered in pale hairs, and contrasts strongly with the all-dark legs and abdomen. Additionally, these spiders have low toxicity, a long life expectancy, and several offspring.
The wheel spider or golden wheel spider, is a huntsman spider native to the Namib Desert of Southern Africa. This spider is distinct from Leucorchestris arenicola, a spider sharing the same common name and found in the same locale. The spider escapes parasitic pompilid wasps by flipping onto its side and cartwheeling down sand dunes at speeds of up to 44 turns per second.
Cerbalus aravaensis is a huntsman spider found in the southern Arava Valley of Israel and Jordan. The species was first described by Gershom Levy of the Hebrew University of Jerusalem in 2007, though news agencies later reported it in 2010 as a new discovery by a team of biologists from the University of Haifa. The spider has a leg span of 14 centimetres (5.5 in), making it the largest member of the family Sparassidae in the Middle East. Males have a body length of 1.85–2.40 centimetres (0.73–0.94 in), while females' body length is 2.20–2.65 centimetres (0.87–1.04 in).
Allocosa brasiliensis is a burrowing wolf spider species from southern South America. Long known to science, it remained almost unstudied until its unusual sexual behavior was described in the early 21st century.
Pachydactylus rangei, the Namib sand gecko or Namib web-footed gecko, is a species of small lizard in the family Gekkonidae. It inhabits the arid areas of Angola, Namibia, and South Africa, and was first described in 1908 by Swedish zoologist Lars Gabriel Andersson, who named it after its finder, German geologist Dr. Paul Range.
Cebrennus rechenbergi, also known as the Moroccan flic-flac spider and cartwheeling spider, is a species of huntsman spider indigenous to the sand dunes of the Erg Chebbi desert in Morocco. If provoked or threatened it can escape by doubling its normal walking speed using forward or backward flips similar to acrobatic flic-flac movements used by gymnasts. C. rechenbergi is the only spider known to use this unique form of rolling locomotion. The discovery of the Moroccan flic-flac spider has influenced biomimetic robot research, resulting in the development of an experimental robot based on the spider's motion.
Seothyra, commonly known as the buckspoor spiders, buck spoor spiders or just spoor spiders, belong to a sand-dwelling, burrowing genus of araneomorph spiders in the family Eresidae. The 13 species are endemic to the arid, sandy flats and semistabilized red dunes of southern Africa. They are sexually dimorphic. The tiny males, which are seldom seen, imitate sugar ants or velvet ants in their appearance and habits, while the females hide in and hunt from their characteristic burrows. They are thermophilous, with males as well as females being most active on hot days.
Tigrosa helluo, commonly known as the Wetland Giant Wolf Spider, is a species of spider belonging to the family Lycosidae, also known as wolf spiders. T. helluo was formerly known as Hogna helluo before differences between dorsal color patterns, habitat preferences, body structures, etc. were discovered. The species is native to the United States, Canada, and Mexico. It can be found across the eastern half of the United States, primarily in the Northeast and New England, and as far west as Nebraska and Kansas. T. helluo can be found in diverse habitats including woods, marshes, fields, and riparian areas. Typically, members of this species prefer to live in wetter areas as opposed to dry environments. Males tend to live for around a year and females will live for close to two years.
Pardosa pseudoannulata, a member of a group of species referred to as wolf-spiders, is a non-web-building spider belonging to the family Lycosidae. P. pseudoannulata are wandering spiders that track and ambush prey and display sexual cannibalism. They are commonly encountered in farmlands across China and other East Asian countries. Their venom has properties that helps it function as an effective insecticide, and it is, therefore, a crucial pesticide control agent.