The Funnel Web Spider is primarily native to Australia and is one of the world’s most recognizable spiders. These spiders are frequently encountered in residential areas, making accurate visual identification a matter of safety and curiosity. Learning to distinguish this species from other large, dark spiders requires focusing on specific, identifiable physical traits rather than general impressions.
Core Physical Characteristics
Funnel Web Spiders are robust, heavy-bodied arachnids with a powerful build. Their body length typically ranges from 1 to 5 centimeters, though some exceptional specimens can be larger. The overall coloration is usually a uniform dark brown to pure black, helping them blend into dark, moist habitats.
The most striking feature is the cephalothorax, the fused head and thorax section. This part is characterized by a hard, glossy, and highly polished surface that is largely free from hair. The shiny, smooth carapace stands in sharp contrast to the abdomen and legs, which may have a thin covering of dark hair.
Key Identifying Structures
Beyond the general body shape and color, several specialized features are crucial for definitive identification. The chelicerae, which house the venom apparatus, are particularly prominent and appear very dark and powerful. These basal segments are thick and muscular, supporting the large fangs.
The fangs are notably large and long, designed to move in a downward and forward motion, which is typical of mygalomorph spiders. When threatened, the spider often rears up, displaying these sizable fangs, which point straight down.
At the rear of the abdomen, the silk-producing organs, known as spinnerets, are typically visible and slightly elongated. In some species, such as the Sydney Funnel Web Spider, the finger-like spinnerets are especially long and easily noticeable.
Distinguishing Males and Females
Distinguishing between the sexes is important, as males are often encountered wandering in search of mates. Female Funnel Web Spiders are generally larger and noticeably more robust than the males. They possess a plumper, more substantial abdomen.
In contrast, the adult male is typically more slender and lighter in build, with longer legs relative to its body size. The most important identifying feature of the male, particularly in the genus Atrax, is a distinct tibial spur located on the second pair of legs. This spur appears as a conical projection on the middle segment of the leg, which is a reliable visual cue.