Tag: PISAURIDAE

Nursery-Web spiders. As the name implies, these spider construct special webs for egg-laying but also for raising their young, something uncommon in most spiders. They have been observed immobilising and leaving prey on the web for their spiderlings. The spiders in this family are very diverse in how different the genera can be from one another. They are medium to large spider that are medically insignificant to humans, though their bite can hurt.

CISPIUS KIMBUIS

CISPIUS KIMBUIS

by anikekirsten
Adult female C. kimbuis

Taxon:

  • Class: Arachnida
  • Order: Araneae
  • Infra-Order: Araneamorph (true spiders)
  • Family: Pisauridae
  • Genus: Cispius
  • Species: C. kimbuis

Female

Around 6mm in body length. Leg span of approximately 10mm diagonally.

Cephalothorax:
Carapace slightly longer than wide, yellowish with two dark bands, centre raised.

Abdomen:
Tear-drop shaped, yellowish brown. Dorsal with two prominent white spots on either side of heart marking, brown rock-textured markings, yellowish circle either side of posterior chevron-like pattern, and faint white spots down centre. Venter yellowish.

Legs:
Yellowish and mottled and banded.

Male

As in female, abdomen smaller, tarsi slightly darker and swollen on pedipalps, legs thinner and longer.

Adult male C. kimbuis
Adult female C. kimbuis

ABOUT THE GENUS

These spiders are commonly known as small funnel-web nursery spiders, and there are only 3 described species in South Africa. They are medium-sized spiders, averaging at 7mm in body length that construct sheet-like webs with a thin tunnel in which they can retreat to. Cispius spiders are often found under bushed and debris on the ground, though rarely do they nest in holes higher in altitude. These spiders are also nocturnal.

ROTHUS VITTATUS

ROTHUS VITTATUS

by anikekirsten
Adult male R. vittatus

Taxon:

  • Class: Arachnida
  • Order: Araneae
  • Infra-Order: Araneamorph (true spiders)
  • Family: Pisauridae
  • Genus: Rothus
  • Species: R. vittatus

Female

Around 9mm in body length. Leg span of approximately 15mm diagonally.

Cephalothorax:
Brown carapace with thick line in centre extending from posterior median eyes, and thin yellow line near edges. Chelicerae dark brown. Coxae light brown. Sternum dark grey with yellow stripe centre. Pedipalps like legs and unmodified.

Abdomen:
Abdomen pointy oval, brown with yellow line dorsal centre and yellow lines radiating to sides. Ventral abdomen yellow with two faint centre stripes anterior to half way.

Legs:
Legs brown and mottled, thin and long. 4, 1, 2, 3.

Male

As in female, with yellow Y marking on carapace, thinner abdomen and modified swollen tarsi on pedipalps. Colours more contrasting.

Adult female R. vittatus
Adult male R. vittatus

ABOUT THE GENUS

Rothus is one of the few genera of spiders where a species may have several variations on how they appear, from differing colours to alternate markings and patterns, and the colour scheme of those patterns can vary as well. As seen between the male and female R. vittatus here, there is a pattern and a colour difference despite being of the same species. The sexual dimorphism doesn’t extend to wildly differing appearance in Rothus spiders as is does in jumping spiders.

They can be identified by their dorsal markings and patterns along with the iconic tuft of setae between the posterior median eyes that “crown” the cephalic region, like a fringe. Rothus spiders are ground-living and free-roaming, only preparing a web when their spiderlings are ready to hatch, where they will remain until the young have left the nursery web.

EUPROSTHENOPS AUSTRALIS

EUPROSTHENOPS AUSTRALIS

by anikekirsten
Adult female E. australis

Taxon:

  • Class: Arachnida
  • Order: Araneae
  • Infra-Order: Araneamorph (true spiders)
  • Family: Pisauridae
  • Genus: Euprosthenops
  • Species: E. australis

Female

About 50mm in body length. Leg span of approximately 120mm diagonally.

Cephalothorax:
Greyish brown carapace, darker oval marking in middle with light stripe running through centre, dark V-like crown marking above eyes. Dark brown X marking connecting each eye, which are also in an X formation. Long brown jaws with small fangs. Light brown edge on sides of carapace.

Abdomen:
Long abdomen tapering toward spinnerets, yellowish brown with darker fading near tip, and short black stripe in centre anterior dorsal, small black spot on either side of stripe. Ventral abdomen brown with darker V marking in middle extending and tapering to spinnerets.

Legs:
Long dark greyish brown legs with light sparse hairs and light bands near joints. Spines on all legs from femur to metatarsus.

Male

As in female but with more defined markings on abdomen and carapace and more pale dorsal abdomen, enlarged tarsi on pedipalps that taper sharply, legs thinner and longer and more spined.

Adult female E. australis
Adult male E. australis

ABOUT THE GENUS

Euprosthenops spiders are graceful, fast, and agile on their webs. They’re also, along with other Pisaurids, maternal animals who carry their egg sac in their chelicera and use their pedipalps and abdomen to keep it secure.

Their webs are contructed in a messy manner with a funnel in which the spider can retreat and secure her egg sac in when her young are about to hatch. Euprothenops are avid hunters, responding to prey signals on their webs with speed.

Furthermore, the silk of Euprosthenops has great tensile strength and is often used in studies concerning the use of spider silk in various industries, including medicine and production.

There are three known species of this genus in South Africa, all of them looking almost the same with slight variations. E. australis, for instance, has a plain-looking dorsal abdomen, whereas the others have a pattern.

PERENETHIS SP.

PERENETHIS SP.

by anikekirsten
Adult male Perenethis sp.

Taxon:

  • Class: Arachnida
  • Order: Araneae
  • Infra-Order: Araneamorph (true spiders)
  • Family: Pisauridae
  • Genus: Perenethis
  • Species: Perenethis sp.

Female

Female characteristics unknown.

Male

About 11mm in body length. Leg span of approximately 30mm diagonally.

Cephalothorax:
Light brown with thick dark band down centre of carapace, from eyes to abdomen, with light stripes running alongside band. Curved dark stripe near edges of carapace. Yellowish chelicerae. Tarsi of pedipalps swollen and dark. Eyes arranged in a squashed X formation.

Abdomen:
Yellowish abdomen that tapers to point near spinnerets, thick dark band down centre with light stripes running alongside. Faint dark lines running down abdomen to spinnerets.

Legs:
Pale yellowish light brown, slight darkening on patella and tibia, darker further on metatarsus and tarsus. Femurs covered in strong dark setae.

Adult male Perenethis sp.
Adult male Perenethis sp.

ABOUT THE GENUS

Perenethis is a typically free-roaming nursery-web spider. They don’t make webs in which to live, though not all nursery-web spiders are wanderers. When a female Nursery-web spider makes an egg sac, she’ll carry it with her, using her chelicera and pedipalps to keep it close and also bending her pedicel so that her abdomen hugs the egg sac.

She’ll stay like this, not eating, until the spiderlings are almost ready. When that time arrives, she then builds a large web on which she secures the egg sac and the slings hatch and emerge and stay on this web with the mother until they’re ready to leave and brave the world on their own.

The web acts as a nursery for the young ones and thus why Pisaurids are called nursery-web spiders.