Tag: HERSILIIDAE

The tree or bark spider, also known as the long-spinnered bark spider. They are are generally found on trees or shrubs, against bark and camouflage almost perfectly due to their flat bodies and cryptic colouration along with the patterns on their abdomens. But these same attributes are also excellent for hiding against rock, especially in dry veld lands. They are medically insignificant to humans.

TYROTAMA ARIDA

TYROTAMA ARIDA

by anikekirsten
Adult female T. arida

Taxon:

  • Class: Arachnida
  • Order: Araneae
  • Infra-Order: Araneamorph (true spiders)
  • Family: Hersiliidae
  • Genus: Tyrotama
  • Species: T. arida

Female

Around 4mm in body length. Leg span of approximately 10mm diagonally.

Cephalothorax:
Round cephalothorax. Carapace light sandy brown with orange-ish oval in centre, faint line on either side, and thin dark lines on side edges. Sternum small and almost triangular, faintly mottled. Pedipalps like legs, unmodified.

Abdomen:
Abdomen oval, yellowish with darker chevron-like pattern down dorsal centre containing two dark inverted triangle markings anterior. Tips of chevron pattern have short prominent spines. Ventral abdomen light brown and faintly mottled. Spinnerets thick and long but tucked under abdomen, reddish brown.

Legs:
First two leg pairs light brown and banded, last two pairs darker brown and banded. Legs 4, 2, 1, 3.

Male

Male characteristics unknown.

Adult female T. arida
Adult female T. arida

ABOUT THE GENUS

Tyrotama is a particularly strange genus of the Long-Spinnered spider family. Contrary to the common name, Tyrotama spiders have relatively short spinnerets though still longer than the average spider’s in proportion to their body size. When looking at one, it’s difficult to see the spinnerets because they’re tucked against the abdomen until they’re needed.

Like when they catch prey. They’ll run around the prey, using their long spinnerets to wrap it with silk, before giving the killing bite.

Tyrotama, like the one I spotted, are found under rocks and stone where they build their nests. They also make their egg sac under these rocks, leaving them hanging and camouflaging them with chips of stone and debris. It sort of looks like a ball of filth hanging on a line. But very, very small.