Sequined Spider

“The “disco-ball”-like plates on the sequined spider’s back confuse predators and make it difficult to see.”

Sequined Spider Summary

The sequined spider, also known as the mirrored or twin-peaked spider, belongs to a genus of comb-feet spiders known as Thwaitesia. Found in almost all states of Australia, the species is known to have a reflective abdomen that plays a crucial role in their camouflage to protect them from predators in the forest canopy.

5 Incredible Sequined Spider Facts

• The sequined spider can change the size of its scales when it feels threatened.
• While it looks quite intimidating due to its color changes, its venom is not dangerous to humans.
• Its color changes look so holographic that you might even be able to see a reflection in it, hence its nickname, “mirror spider.”
• They’re very tiny creatures, only about 1/5th the size of an aspirin!
• The females are a little larger than the males.

Scientific Name

The sequined spider, scientifically known as the Thwaitesia argentiopunctata, belongs to Thwaitesia – a genus of comb-footed spiders. This arachnid was first discovered and described as such by the entomologist Octavius Pickard-Cambridge back in 1881. As of 2021, this genus consists of 23 species of comb-footed spider cousins, one of which is the sequined spider.

Sequined Spider Appearance

The sequined spider, also known as the mirror spider, is unique in its appearance. Sequined spiders have reflective, silver patches all over their abdomen. The patches can appear like pieces of a mirror, as thin as scales, glued onto the animal’s back. In addition, a rather intriguing feature is that these reflective pieces can change their size when the spider feels threatened. These scale-like structures are made of a material known as reflective guanine, which enables the spider’s color-changing ability. Reflective patches aside, their abdomen is usually cream, yellow, green, or red at the base. This is one of the most beautiful spiders in the world, owing to the reflective “sequins” on its body.

This spider is very small. The female sequined spider is slightly larger than the male, but overall, both are less than a quarter of an inch in body size. The male is about 0.12 inches long, while the female is about 0.16 inches.

Sequined Spider Behavior

Like most spiders, sequined spiders are solitary animals that prefer to live on their own instead of in groups. Nevertheless, a group of sequined spiders (usually a mother and her young) is known as a clutter or cluster. In terms of their personality, these arachnids are generally not aggressive unless provoked or threatened.

Sequined Spider Habitat

The sequined spider is usually found on the leaves of trees in Australia. The climate of Australia is warm and tropical. Like all other spiders, the sequined spider is also a cold-blooded animal that prefers to stay in a warmer area to regulate its body temperature according to its surroundings. These warmer and wetter climates increase this spider’s survival rate and population size.

Sequined spiders will climb trees in Australian forests and build webs between several branches. This allows them to catch insects to feed on.

Sequined Spider Diet

The sequined spider is a carnivore that feeds on smaller insects. Considering its small size, it’s often likely to fall prey to moths, lizards, birds, and other larger arthropods.

What Do They eat?

The diet of a sequined spider usually consists of insects, particularly mosquitoes, flies, gnats, and sometimes even other smaller spiders. Thus, these creatures play a significant role in keeping nature’s natural balance intact. They generally catch their prey by building a web and waiting for the creatures to fly into it and get stuck on the sticky strings. The spider then kills the animals with its venom and sucks out their blood and juices.

What Eats them?

The sequined spider often falls prey to larger animals, including bigger spiders, centipedes, scorpions, and even some insects. In addition, birds, reptiles, and small mammals might also prey on this arachnid.

Predators and Threats

As mentioned above, the sequined spider can fall prey to several larger arthropods, mammals, and birds. In particular, lizards enjoyably feast on sequined spiders and can become a threat to their population if they’re found in large numbers within the spider’s habitat. Moreover, birds also prey on them. Spider wasps can also be a major threat, as they pierce through the sequined spider, leaving it paralyzed before it kills them.

Monkeys may consume these spiders in Australia if they stumble upon them or if there is a scarcity of other food.

Male sequined spiders can be a threat to one another during the mating season, as they will fight each other for mates.

In terms of environmental threats, the sequined spider does not fare well in cold temperatures. If any sharp temperature changes occur, they may not survive.

Sequined Spider Reproduction

Since sequined spiders usually live alone and keep to themselves, the task of finding a mate is difficult. The male seeks out sexually mature females and impregnates them.

Usually, a female sequined spider signals that she wishes to mate through pheromones or communicative chemicals. These chemicals produce a silk thread that lingers when she’s looking to mate. When the male sequined spider sees this, he will approach the female, which initiates a possible mating process.

Once they’ve spotted one another, and there are no other male contenders in the way, the male must signal to the female that he belongs to the same species as her. To prove that he is also a sequined spider, the male strums a unique signal on the female’s silk tail. Once the female approves, she positions herself for sex, and the male deposits his sperm in the female’s genital opening. These are then stored within her reproductive organs and used to fertilize the eggs released from her ovaries. About 30 eggs are laid at once, which hatch after a two-to-three-week gestation period.

As with many arachnid species, sequined spiders only mate once in their life. The females die soon after giving birth to spiderlings.

Sequined Spider Babies

Spiderlings are often so small that they can’t easily be spotted with the human eye. As a result, not much information has been documented on their appearance. They likely remain with their mothers for a week, leaving soon after.

Young spiderlings usually feed on everything they find, including the egg sac they were contained in before hatching. Other parts of their diet include small flies, tiny insects, and even dead spiderlings or unhatched eggs that did not survive.

After a couple of weeks, the spiderlings grow and begin to mature a bit. They eventually start feeding on a more protein-oriented diet of larger insects and begin to spin webs to catch food.

The web of a spiderling is often wider at the top and narrow at the bottom so that it is suitable for capturing pollen and tiny bugs.

Lifespan

A sequined spider usually lives up to one year. 

As they age, their immune systems become weak, so parasites like the Mermethid nematode penetrate their bodies, gradually weakening them further.

Population

The exact number and population of the sequined spider is unknown since they are only found in the forests of Australia. Hence, their conservation status is not listed. However, it is possible that the Australian bushfires of 2020 affected their population as they did with many Australian forest-dwelling animals.

Related Animals

• Redback Spider
• Grass Spider
• Peacock Spider
• Hobo Spider

1. Australian Geographic, Available here: https://www.australiangeographic.com.au/
2. Spider Identifications, Available here: https://spideridentifications.com/mirror.html
3. Science Friday, Available here: https://www.sciencefriday.com/articles/picture-of-the-week-sequined-spider/