Tag: CORINNIDAE

These spiders are known as dark sac spiders, due to their colouration. They are often found outside, being very shy of humans. Some species within this family are also ant-mimics. Like all sac spiders, they spin a little silk sac for a temporary hide or to lay eggs or molt, though they are generally a free-roaming hunter spider.

CASTIANEIRA SP.

CASTIANEIRA SP.

by anikekirsten
Adult female Casteianeira sp.

Taxon:

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

Female

About 8mm in body length. Leg span of approximately 20mm diagonally.

Cephalothorax:
Carapace red-brown with faint white starburst pattern. Sternum reddish shield shape. Chelicera red with black ends. Peidpalps reddish.

Abdomen:
Abdomen oval with taper, dark with two broad lighter bands across, first anterior and second posterior. Anterior band with slightly brighter borders. Ventral greyish with two dark lines posterior and dark epigyne.

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

Male

Unknown.

Adult female Casteianeira sp.
Adult female Casteianeira sp.

ABOUT THE GENUS

The ant-mimic spiders of the genus Castianeira are near perfect mimics of the ant species Anoplolepis custodiens, known commonly as the crazy or pugnacious ant, what South Africans often refer to as malmiere. These spiders are often found around Micaria sp. spiders as well. Castianeira sp. is difficult to find due to this, along with their movement being very ant-like and their tendency to bob their abdomen up and down like the ant they’re mimicking does. Like other sac spiders, these will only make a sac web to retreat in due=ring the day, though this species can be found resting in abandoned tunnels or grooves under rocks and debris.

CORINNIDAE SPP.

CORINNIDAE SPP.

by anikekirsten
Adult female Corinnidae spp.

Taxon:

  • Class: Arachnida
  • Order: Araneae
  • Infra-Order: Araneamorph (true spiders)
  • Family: Corinnidae
  • Genus: Unknown, possibly Messapus
  • Species: Unknown

Female

About 8mm in body length. Leg span of approximately 20mm diagonally.

Cephalothorax:
Carapace yellow-brown with thin dark stripe down centre, thin black border around raised cephalic region, and 3 black spots on either side near edges. Thin faint white line above chelicera. Chelicera reddish brown and long. Sternum brown with faint dark border.

Abdomen:
Abdomen oval and brown, mottled faintly, with 2 short dark lines anterior centre of dorsum followed by two faint dark patches in column down centre, then two columns of irregular patchy lines down to spinnerets. Ventral abdomen yellowish with faint broad band down centre. Epigyne dark.

Legs:
Legs yellowish reddish brown and banded. Metatarsus and tarsus greyish. Coxae yellowish brown.

Male

Unknown.

Adult female Corinnidae spp.
Adult female Corinnidae spp.

ABOUT THE GENUS

Corinnids are fast, agile ground-hunting spiders. They often prey on ants, but also sometimes on termites, wasps, and other small invertebrates. Like other sac spiders, they build silken retreats that look like cocoons where they stay to rest and/or recover or when they’re about to molt.

The females lay their eggs in such retreats as well. I can’t find literature on the maternal nesting habits of Corinnidae, however, and haven’t been able to observe any such behaviour so I have no idea whether the female remains to guard her eggs and spiderlings or not.

Corinnids are diurnal, unlike most other spiders, meaning that their peak active time is during the day. This is advantageous to them considering they prey on ants and termites and mimic them. Their common names are Ground Sac Spider, Ant-Mimicking Sac Spider, and Dark Sac Spider.