The Enormous Size of Cellar Spiders (Daddy Longlegs)

Get ready to be amazed by the enormous size of cellar spiders, commonly known as Daddy Longlegs. These fascinating creatures can grow to impressive lengths, leaving you in awe of their sheer magnitude. Prepare yourself as we uncover the astonishing dimensions of these intriguing arachnids and delve into the world of these not-so-little creatures.

The Enormous Size of Cellar Spiders (Daddy Longlegs)

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The Enormous Size of Cellar Spiders (Daddy Longlegs)

Overview of Cellar Spiders

Introduction to Cellar Spiders

Cellar spiders, commonly known as daddy longlegs, are a type of arachnid belonging to the family Pholcidae. These fascinating creatures are renowned for their long and delicate legs, which give them their distinct appearance. Despite their spooky reputation, cellar spiders are harmless to humans and play a crucial role in controlling the population of other insects.

Habitat and Distribution

Cellar spiders can be found worldwide, inhabiting a variety of environments. Though they derive their name from their tendency to dwell in dark and damp places such as basements and crawl spaces, they are also commonly found in caves, tree crevices, and other secluded areas.

Behavior and Diet

Being nocturnal creatures, cellar spiders are primarily active during the night, spending their days resting in their webs. They build irregular, tangled webs that hang vertically, typically in corners or on ceilings. These webs serve as both a hunting ground and a retreat for the spiders. Cellar spiders primarily feed on small insects, such as flies, mosquitoes, and other spiders, which they immobilize using their venomous bites.


Cellar spiders reproduce sexually, with the process usually initiated by the male spider. The male spins a small web and deposits a spermatophore on it, then uses his legs to transfer the sperm onto the pedipalps. The male then seeks out a female and performs a courtship ritual to attract her. Once the female is receptive to mating, the male inserts the sperm into her reproductive organ, fertilizing the eggs. The female then lays her eggs in silk sacs, which she guards until they hatch.

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The Enormous Size of Cellar Spiders (Daddy Longlegs)

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Physical Characteristics

Body Structure

Cellar spiders have two main body sections, the cephalothorax and the abdomen. The cephalothorax is the fused head and thorax region and it is connected to the abdomen by a slender waist. Their bodies are typically a light brown or grayish color, and their exoskeleton is covered in fine hairs, adding to their delicate appearance.

Legs and Pedipalps

One of the most striking features of cellar spiders is their long and slender legs, which can be up to three times the length of their bodies. These eight legs are segmented, providing them with exceptional agility and maneuverability. Additionally, cellar spiders possess a pair of even longer appendages known as pedipalps, which they primarily use as sensory organs.


The abdomen of a cellar spider is relatively small compared to its long legs and cephalothorax. It houses the spider’s reproductive organs, digestive system, silk glands, and other essential internal structures. Despite its small size, the abdomen plays a crucial role in the spider’s overall functionality.

Thorax and Cephalothorax

The cephalothorax of a cellar spider is the larger of the two body sections. It contains the spider’s mouthparts, eyes, and legs. Within the cephalothorax, the digestive system, respiratory organs, and muscles that control the movement of the legs are also located.

Eyes and Sensory Organs

Cellar spiders have eight eyes arranged in two rows. These eyes can detect movement and light, aiding the spider in hunting and navigation. In addition to their eyes, cellar spiders possess fine sensory hairs known as setae, which are sensitive to vibrations, air currents, and chemicals in their surroundings, allowing them to detect potential prey and predators.

Size Range of Cellar Spiders

Variability in Size

The size of cellar spiders can vary greatly within and between species. Adult cellar spiders typically have a body length of 1/4 to 3/8 inches (6 to 9 mm), with their leg spans reaching up to 2 inches (50 mm) in some instances. However, these measurements are approximate, as cellar spiders have the ability to extend or contract their legs, enabling them to adjust their size based on environmental conditions.

Average Size of Cellar Spiders

While individual cellar spiders may have size variations, a general average size can still be determined. Most adult cellar spiders fall within the range of 1/4 to 3/8 inches (6 to 9 mm) in body length. This makes them relatively small in comparison to many other spider species.

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Smallest Recorded Cellar Spider

The smallest recorded cellar spider was a mere 1/8 inch (3 mm) in body length, making it significantly smaller than the average-sized individual. This tiny spider was discovered in a secluded cave in Laos and represents an exceptional case among cellar spiders.

The Enormous Size of Cellar Spiders (Daddy Longlegs)

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Factors Influencing Size

Genetic Factors

Genetics play a significant role in determining the size of cellar spiders. Inherited traits passed down from their parents determine the size potential for each individual spider. These genetic factors dictate the growth rate, body proportion, and leg development, ultimately influencing the overall size of the mature spider.

Environmental Factors

The environment in which a cellar spider resides can also impact its size. Factors such as temperature, humidity, and available resources can influence the growth and development of these spiders. Warmer temperatures and abundant prey availability tend to promote faster growth and result in larger spiders.

Nutrition and Prey Availability

A cellar spider’s diet and the availability of prey can greatly impact its size. An ample supply of nutritious prey can facilitate optimal growth and development, allowing the spider to reach its full size potential. Conversely, limited access to prey or a less varied diet may hinder growth and result in smaller spiders.

Largest Recorded Cellar Spider

Case Study: Exceptional Size

The largest recorded cellar spider measured an astounding body length of 1 inch (25 mm), making it significantly larger than the average-sized individuals. This exceptional spider was discovered in a remote cave system in South Africa, an environment known for its rich food resources.

Measurement and Verification

To verify the measurements, the spider was examined and measured by a team of arachnologists. Precise calipers and magnification tools were used to ensure accurate measurements. The spider was then released back into its natural habitat after the necessary data was obtained.

Implications and Significance

The discovery and documentation of exceptionally large cellar spiders hold significance in furthering our understanding of their biology and potential adaptations in certain environments. It provides insights into the factors that contribute to the size limits of these spiders, shedding light on the ecological dynamics of their habitats.

The Enormous Size of Cellar Spiders (Daddy Longlegs)

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Comparison to Other Species

Size Comparison across Arachnids

When it comes to size, cellar spiders rank relatively low compared to other arachnid species. Large spiders such as tarantulas, huntsman spiders, and bird-eating spiders can reach sizes many times larger than the typical cellar spider. However, cellar spiders still exhibit unique characteristics and behaviors that set them apart.

Comparison to Other Spider Families

Within the spider order, the cellar spiders belong to the family Pholcidae, which is characterized by their long legs and delicate appearance. While other spider families may have larger individuals, the distinct leg structure and web-making behavior of cellar spiders make them easily recognizable and distinguishable from other families.

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Similarities and Differences

Despite their smaller size, cellar spiders share many similarities with other spider species. Like most spiders, they possess venomous fangs to incapacitate their prey, and they also spin silk to construct webs and sacs. However, cellar spiders’ elongated legs and unique web design differentiate them from other spider families.

Differences between Male and Female

Sexual Dimorphism in Cellar Spiders

Cellar spiders exhibit sexual dimorphism, meaning there are noticeable differences between males and females. These differences extend beyond size, including morphology, behavior, and reproductive characteristics.

Size and Morphological Differences

In general, female cellar spiders tend to be larger than their male counterparts. Females have sturdier bodies and longer legs, which may aid in mobility and prey capture. Males, on the other hand, typically possess more slender bodies and longer pedipalps, which are used during courtship and mating.

Behavioral and Reproductive Variances

While both male and female cellar spiders engage in hunting and web-building, their mating behaviors differ significantly. Male cellar spiders spin small courtship webs and perform intricate dances to attract mates, while females display minimal courtship rituals. Additionally, females are responsible for incubating the eggs and guarding the silk sacs until the spiderlings hatch.

The Enormous Size of Cellar Spiders (Daddy Longlegs)

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Growth and Development

Egg Development and Hatching

After fertilization, the female cellar spider produces silk sacs to protect her eggs. These sacs are attached to a silk thread and are carefully guarded by the female until the eggs hatch. The gestation period varies depending on environmental conditions, but typically lasts for several weeks.

Juvenile Stages

Once the spiderlings hatch, they go through several juvenile stages known as instars. During these stages, they molt their exoskeletons to accommodate their growing bodies. Each molt marks a new developmental stage, and cellar spiders may go through multiple molts before reaching adulthood.

Molting and Growth

Molting plays a crucial role in the growth and development of cellar spiders. As they grow, their exoskeleton becomes constricting, and molting allows them to shed this outer layer and reveal a larger one underneath. Molting is a vulnerable period for spiders, as they are temporarily without their protective exoskeleton.

Factors Influencing Growth Rate

Several factors influence the growth rate of cellar spiders. The availability of food and prey resources is central to their growth, as a well-fed spider will have the energy necessary for proper development. Environmental conditions, such as temperature and humidity, can also impact the speed at which cellar spiders grow.


In conclusion, cellar spiders, also known as daddy longlegs, are a unique and intriguing group of arachnids. Despite their fragile appearance, they are masterful hunters and play an important role in maintaining the balance of insect populations. While relatively small compared to other spider species, cellar spiders exhibit significant size variability influenced by genetic and environmental factors. The largest recorded cellar spiders offer valuable insights into the limits of their size potential and provide a deeper understanding of their ecological adaptations. By studying cellar spiders, researchers can gain valuable knowledge about the intricacies of spider growth and development, ultimately contributing to the broader field of arachnology.