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Darwin’s Bark(Caerostris darwini)

Darwin’s bark spider of the orb-weaver family is known for producing the largest orb webs, spanning between 900 – 28000 sq. cm. This unique spider species attains its name after Charles Darwin, the famous English naturalist.

Darwin’s Bark Spider

Scientific Classification

Physical Description and Identification

Adults

Size: Female spiders are 0.7 – 0.9 inches (1.7 – 2.2 cm) and the comparatively smaller male spiders are round 0.2 inches (0.5 cm).

Color: Females have a black body, while their cephalothorax, appendages, and abdomen remain covered with white hairs.

Male spiders appear light brown or reddish, though the arrangement of white hairs on certain parts of their body is closely similar to their female counterparts.

Other Characteristic Features: Female spiders have two pairs of humps on the upper portion of their cephalothorax. One pair lies to the side and the other behind. Male spiders exhibit their palpal bulb or genital organ with a straight-tipped conductor. The embolus is long enough, having a spoon-shaped pattern towards the end.

Darwin Bark Spider Size

Eggs

These spiders lay their eggs into a sac produced by them beforehand.

Spiderlings

There are no concrete records about the description and identification of the spiderlings. However, it may be assumed that, like most other species’ spiderlings, they too disperse from their mother after maturation.

The Web

Their strong, tough web is approximately 3 ft wide, also being 10 times being more durable than a similar-sized Kevlar. They build webs over a water body, and the orb remains suspended above. In this way, they can catch prey that flies near the surrounding terrain. A single web might contain about 32 mayflies in one go.

Darwin Bark Spider Web

Are Darwin’s Bark Spider Poisonous

Darwin’s bark spiders have low venom levels and their bites though rare would do no harm.

Quick Facts

Distribution Madagascar
Habitat Near waterbodies
Web Type Orb web
Diet Mayflies and other aquatic insects
IUCN Conservation Status Not Listed
Darwin Bark Spider Silk

Did You Know

  • Darwin’s bark spider’s web is the largest, strongest, and most complex worldwide. The web’s bridge line could extend up to 82 ft, and the spider can cross a river depending on its web. The silk that it produces is the strongest amongst all spider species.
  • Their discovery dates back to the year 2009, in Madagascar’s Andasibe-Mantadia National Park.
  • The female spider either eats the male counterpart or castrate it post-copulation.

Image Credits: I.ytimg.com, 4.bp.blogspot.com, 3.bp.blogspot.com, Asknature.org

Darwin’s bark spider of the orb-weaver family is known for producing the largest orb webs, spanning between 900 – 28000 sq. cm. This unique spider species attains its name after Charles Darwin, the famous English naturalist.

Darwin’s Bark Spider

Physical Description and Identification

Adults

Size: Female spiders are 0.7 – 0.9 inches (1.7 – 2.2 cm) and the comparatively smaller male spiders are round 0.2 inches (0.5 cm).

Color: Females have a black body, while their cephalothorax, appendages, and abdomen remain covered with white hairs.

Male spiders appear light brown or reddish, though the arrangement of white hairs on certain parts of their body is closely similar to their female counterparts.

Other Characteristic Features: Female spiders have two pairs of humps on the upper portion of their cephalothorax. One pair lies to the side and the other behind. Male spiders exhibit their palpal bulb or genital organ with a straight-tipped conductor. The embolus is long enough, having a spoon-shaped pattern towards the end.

Darwin Bark Spider Size

Eggs

These spiders lay their eggs into a sac produced by them beforehand.

Spiderlings

There are no concrete records about the description and identification of the spiderlings. However, it may be assumed that, like most other species’ spiderlings, they too disperse from their mother after maturation.

The Web

Their strong, tough web is approximately 3 ft wide, also being 10 times being more durable than a similar-sized Kevlar. They build webs over a water body, and the orb remains suspended above. In this way, they can catch prey that flies near the surrounding terrain. A single web might contain about 32 mayflies in one go.

Darwin Bark Spider Web

Are Darwin’s Bark Spider Poisonous

Darwin’s bark spiders have low venom levels and their bites though rare would do no harm.

Quick Facts

Distribution Madagascar
Habitat Near waterbodies
Web Type Orb web
Diet Mayflies and other aquatic insects
IUCN Conservation Status Not Listed
Darwin Bark Spider Silk

Did You Know

  • Darwin’s bark spider’s web is the largest, strongest, and most complex worldwide. The web’s bridge line could extend up to 82 ft, and the spider can cross a river depending on its web. The silk that it produces is the strongest amongst all spider species.
  • Their discovery dates back to the year 2009, in Madagascar’s Andasibe-Mantadia National Park.
  • The female spider either eats the male counterpart or castrate it post-copulation.

Image Credits: I.ytimg.com, 4.bp.blogspot.com, 3.bp.blogspot.com, Asknature.org

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