Penestomidae
Construct silk retreats in tunnels, suggesting an ambush or sit-and-wait predatory strategy.·Seven species are listed as Data Deficient; P. egazini and P. montanus are considered Rare.
Penestomus is a genus of African araneomorph spiders belonging to its own family, Penestomidae, distinct from the Eresidae family. These spiders are characterized by their flat bodies and unique eye placement, and are found exclusively in South Africa and Lesotho. Much of their ecology remains a mystery, though they inhabit silk retreats in tunnels.
Key Facts
- ›Penestomus spiders are distinguished by their flat bodies and the specific arrangement of their posterior lateral eyes.
- ›The genus is endemic to South Africa and Lesotho, with most species found only in South Africa.
- ›They construct silk retreats within tunnels located in boulders or under ground debris.
- ›Prey remains indicate a diet that includes ants, weevils, and small crickets.
- ›Most species are poorly understood, with seven listed as Data Deficient and two as Rare.
- ›The family Penestomidae was established in 2010, separating these spiders from the Eresidae family.
South Africa, Lesotho
- Flat Body
- Posterior Lateral Eyes Are Less Than Three Eye Diameters Behind the Posterior Median Eyes
- Eight Eyes Arranged In Two Rows, With the Posterior Eye Row Slightly Recurved and More Widely Spaced Than the Anterior Eyes
- Carapace Is Subrectangular With A Shallow Ovoid Fovea
- Sternum Is Ovoid, Longer Than Wide, and Not Fused To the Labium
- Fang Furrow Promargin Armed With Four To Six Teeth
- Fang Furrow Retromargin Armed With Two To Three Teeth
Live In Silk Retreats
About Penestomidae
Penestomus
Penestomus is a genus of small African araneomorph spiders that constitutes its own family, Penestomidae. First described by Eugène Louis Simon in 1902, these spiders are distinguished by their flat body shape and a specific arrangement of their posterior lateral eyes, which are positioned closer to the posterior median eyes compared to their relatives in the Eresidae family. The genus is exclusively found in South Africa and Lesotho, with the vast majority of its species endemic to South Africa.
Ecology and Habitat
Much of the ecological behavior of Penestomus spiders remains poorly understood. They inhabit silk retreats constructed within tunnels, typically located in boulders or beneath ground debris. Analysis of prey remains suggests their diet consists of small invertebrates such as ants (Formicidae), weevils (Curculionidae), and small crickets (Gryllidae), indicating they are likely ambush predators utilizing their silk-lined burrows.
Taxonomy and Conservation
Originally placed within the family Eresidae, Penestomus was elevated to its own family in 2010, with current research suggesting it is more closely related to the Zodariidae family. The conservation status of most Penestomus species is concerning due to limited scientific knowledge. Seven of the nine known species are classified as Data Deficient, while two species, P. egazini and P. montanus, are designated as Rare due to their restricted geographic distributions.
Source: Wikipedia ↗
Frequently Asked Questions
What are Penestomus spiders?
Penestomus spiders are a genus of African araneomorph spiders that form their own taxonomic family, Penestomidae. They are known for their flat bodies and are found only in South Africa and Lesotho.
Where do Penestomus spiders live?
The natural habitat of Penestomus spiders is limited to South Africa and Lesotho. They create silk retreats within tunnels, often found in boulders or under debris on the ground.
What makes Penestomus spiders distinct?
Penestomus spiders are distinguished from the Eresidae family by their flattened body shape and the position of their posterior lateral eyes, which are closer to the posterior median eyes than in Eresidae.
What do Penestomus spiders eat?
While little is known about their specific diet, prey remains found in their habitats suggest they consume ants (Formicidae), weevils (Curculionidae), and small crickets (Gryllidae).
Are Penestomus spiders well-studied?
No, most species within the genus Penestomus are poorly known. Seven species are classified as Data Deficient, and two species are considered Rare due to their limited geographic ranges.
How large are Penestomus spiders?
Penestomus spiders are quite small, with a total body length typically ranging from 3 to 6 millimeters.
Related Spider species
Uloboridae
Uloboridae, also known as cribellate orb weavers or hackled orb weavers, are a family of non-venomous spiders found almost worldwide. Their most distinctive trait is the complete absence of venom glands, a trait that evolved secondarily, leading them to rely on a unique hunting strategy involving specialized silk and digestive fluids.
Dipluridae
Dipluridae, commonly known as curtain-web spiders, are a family of mygalomorph spiders characterized by two pairs of booklungs and stabbing chelicerae. While historically encompassing genera now moved to other families, the current Dipluridae are primarily found in South America and the Caribbean, known for building messy funnel-webs or silk-lined burrows.
Cyatholipidae
Cyatholipidae is a family of spiders first described by Eugène Simon in 1894. Primarily inhabiting moist montane forests, some species have adapted to drier savannah environments. A distinctive characteristic of most members is their habit of hanging beneath sheet webs.