Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

A rarity among arachnids, predatory whip spiders have a sociable family life

14.03.2007
Whip spiders, considered by many to be creepy-crawly, are giving new meaning to the term touchy-feely.

In two species of whip spiders, or amblypygids, mothers caress their young with long feelers and siblings stick together in social groups until they reach sexual maturity. This is surprising behavior for these arachnids, long-thought to be purely aggressive and anti-social, according to a Cornell researcher.

Social behavior is extremely rare in arachnids, a class that includes spiders, amblypygids, scorpions and mites, among others; only 76 (or less than 0.1 percent) out of the 93,000 known arachnid species have been observed living in social groups. The research, appearing in recent issues of both the Journal of Arachnology and Natural History magazine, marks the first time social behavior has been reported in amblypygids.

"This was the best example I had ever seen of friendly behavior in an arachnid," said Linda Rayor, senior research associate in entomology and the lead author of both articles. Rayor describes in the articles how mothers habitually stroke their offspring with their long, thin whiplike front legs and how the siblings congregate in social groups.

... more about:
»Rayor »amblypygid »arachnid »diadema »siblings

"I was amazed at how incredibly interactive the groups are," said Rayor. "They are in constant tactile contact with one another. They are constantly exploring one another and interacting with their siblings."

Scientists have long thought these creatures were solitary and cannibalistic predators, as past studies have focused mainly on the adult's dramatic courtship and fighting behaviors. Rayor believes that because young amblypygids slip easily into tight crevasses and their coloring matches their backgrounds, the social behavior of the youngsters has been missed in the wild.

Rayor's research on two species in captivity (the dime-sized Phrynus marginemaculatus from Florida and a much larger Damon diadema from Tanzania) suggests that both mothers and siblings form long-lasting, socially interactive groups. As soon as the siblings approach sexual maturity though (about 12 to 14 months of age), they start showing aggressive, life-threatening behavior toward each other.

To test if D. diadema were congregating simply to inhabit a preferred site in the cages, Rayor and Lisa Taylor, CALS '01, created cages with uniform plywood surfaces and found that the siblings grouped together but changed their location daily, suggesting individuals preferred proximity to each other over a specific location. When siblings were removed from a familiar cage and scattered about another large unfamiliar cage, within minutes, they gathered back together.

In one experiment conducted by Rayor and Rachel Walsh, A&S '05, when 7- to 9-month-old D. diadema were separated from their families and later returned to cages with either their own group or an unfamiliar group, they reacted more aggressively toward the new group than their own.

Rayor suspects that benefits of whip spider social behavior include enhanced safety from predators. Although there are few reports of other creatures eating them, a mother nearby may offer young amblypygids some protection. When Rayor disturbed D. diadema youngsters, they gathered closer to each other or their mother. Now and then, the mother threatened Rayor. The adolescents, though, tended to scurry away and hide when faced with threat. While sharing prey is an advantage for other arachnids with social tendencies, Rayor said she has yet to witness amblypygids intentionally sharing prey.

More than 100 amblypygid species live in tropical areas worldwide. These arachnids, whose bodies range from one-eighth to about one and three-quarters inches long, have two elongated pedipalps (like arms) in front tipped with stilettos that are used to capture prey. The first pair of legs has developed into long whiplike feelers that are three to four times longer than the remaining three pairs of legs. The exceptionally flexible whips can move 360 degrees around their bodies and are covered with hairs that sense their environment.

Krishna Ramanujan | EurekAlert!
Further information:
http://www.cornell.edu

Further reports about: Rayor amblypygid arachnid diadema siblings

More articles from Life Sciences:

nachricht Water forms 'spine of hydration' around DNA, group finds
26.05.2017 | Cornell University

nachricht How herpesviruses win the footrace against the immune system
26.05.2017 | Helmholtz-Zentrum für Infektionsforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

How herpesviruses win the footrace against the immune system

26.05.2017 | Life Sciences

Water forms 'spine of hydration' around DNA, group finds

26.05.2017 | Life Sciences

First Juno science results supported by University of Leicester's Jupiter 'forecast'

26.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>