Record-Breaking Trapdoor Spider

Record-Breaking Spider

• A trapdoor spider known as "Number 16" was documented in 1974 and lived for 43 years.
• The spider lived in North Bungulla Reserve in southwestern Australia.

Barbara York Main's Study

• Australian arachnologist Barbara York Main began a long-term study of trapdoor spiders in 1974.
• Main's study focused on trapdoor spider families and their survival in southwestern Australia, noting that these spiders create trapdoor entrances to their burrows to ambush prey.

Number 16's Life

• In 1974, Main identified 10 spiders to track, including "Number 16", who was part of a spiderlings group.
• Number 16 became the longest-living spider known to science at 29 years old, surpassing a Mexican tarantula that lived to 28.
• The spider survived until 2016 and her death was likely caused by a parasitic wasp piercing her burrow.

Trapdoor Spider Adaptations

• Trapdoor spiders use efficient predation techniques, such as a "sit-and-wait" hunting strategy to conserve energy and reduce predation risk.
• Their camouflaged burrows provide shelter and protection, aiding in predator avoidance and coping with harsh conditions.
• The low energy consumption and slow metabolism of trapdoor spiders allow them to survive for extended periods with minimal food intake.
• Trapdoor spiders are environmentally resilient and can tolerate extreme temperatures and humidity in various environments.
• Defensive mechanisms of the spiders involve quick retreat into their burrows to hide from potential threats.
• Trapdoor spiders demonstrate resilience to starvation by entering periods of dormancy or reduced activity when food is scarce. Their burrows are constructed from soil, plant material, and silk, featuring hinged doors for ambushing prey that triggers vibrations nearby while hunting nocturnally.

Trapdoor Spiders vs Tarantulas

• Trapdoor spiders are related to tarantulas, belonging to the Avicularioidea superfamily.
• Unlike tarantulas, trapdoor spiders rely on burrows and ambush techniques, with similar anatomical features and formidable chelicerae.

Toxicity of Male Funnel-Web Spiders

• Male funnel-web spiders develop much deadlier venom than females.
• Australian funnel-web spiders produce delta-hexatoxins, toxins that can cause human fatalities.
• Delta-hexatoxins exert neurotoxic effects by keeping nerves turned on, leading to overstimulation.
• Male funnel web spiders were responsible for most human deaths as their venom was deadlier than females.
• The toxins originally evolved to kill insects such as cockroaches and flies.
• As male funnel web spiders mature, they leave their burrows to find females and encounter dangerous vertebrate predators like the dunnart.
• Natural selection caused the insect-specific venom to switch into a vertebrate-specific defensive venom.
• Research aims to better understand how funnel web spider venom affects the human body and to develop evidence-based treatment strategies for bite victims.

Web Architecture and Predator Avoidance

• Spiders' webs serve not only to catch prey but also to outwit predators through adaptations.
• Spiders building webs that expose them to predators tend to be brightly colored, armored, or camouflaged.

Types of Spiderwebs

• Two-dimensional (2D) webs can be flat and on a single plane, with or without a refuge for the spider.
• Three-dimensional (3D) designs, such as tangles or sheet-and-tangles, offer more space for the spider to hide.

Web Architecture and Anti-Predator Adaptations

• Brightly colored and armored spiders are found in 2D web structures without a refuge.
• Camouflaged spiders are commonly in 2D webs with a refuge.
• Spiders with 3D webs are often neutral in coloration.
• Spiders that build 3D webs display fewer offensive behaviors; fleeing is a common reaction if protection is breached.

Tactics for Survival

• Hiding, staying still, or blending in with the environment are effective methods for avoiding predation.
• Bright, dangerous coloration can also warn predators, indicating armaments or poisonous attributes.
• Some species collect leaves to hide inside their webs, enhancing camouflage.
• Some Cyclosa species use shed exoskeletons in a line, and some spiders build decoys to mimic their shape, fooling predators.

Spider Silk and Genetic Modification

• Spider silk is a light, flexible, and incredibly strong material.
• Spider silk is stronger than steel, more resistant and elastic than rubber and nylon, and twice as strong as Kevlar, at equal diameters and weights.
• Spider silk can be used in ropes, nets, parachutes, bulletproof clothing, shoes, artificial tendons, and ligaments.
• Researchers at the University of Wyoming are developing spider goats, genetically modified goats that produce the protein used to make silk in their milk.

Genetically Modifying Goats

• Scientists isolate a gene of interest, the orb-weaving spider gene that allows them to produce dragline silk, and a vector such as a plasmid from pBC1 bacteria.
• Digestion occurs when the gene of interest and plasmid are cut at specific DNA sequences using restriction enzymes like TspRI enzymes.
• Ligation takes place with the placement of the gene of interest in the vector through DNA ligase joining the sugar-phosphate backbones of the gene and vector, resulting in a recombinant vector.
• The recombinant vector is inserted into a host cell, a process called transfection.
• The genetically modified nucleus is placed into a fertilized egg cell where the dragline silk gene is added to the goat's DNA, resulting in offspring that produce the silk protein in their milk.