Open-holed trapdoor spider

Morphology

This species belongs to the genus Stanwellia. Stanwellia differs from species of Anaminae by the lack of a posterior heel on the maxilla, and the presence of cuspules on the antero-mesal corner of the maxilla. Species of Nemesiidae are often distinguished from each other using two main characters on adult males. First is the large spur found on the front legs, used to engage with the female during mating. Second, by the shape and size of the palps, the sexual organs males use to inseminate females during mating. Females of different species are rarely distinguishable from each other.

Evolution

The Australian members of the Nemesiidae have a complex evolutionary history. Researchers at the WA Museum have recently resolved the relationships between the genera presented here using molecular tools and formal changes to the taxonomy are forthcoming, but further work is required to fully understand the species level diversity.
This genus is strongly affilliated with New Zealand and the mesic zones of Australia. They are sister to all other Australian nemesiids and preliminary data suggest that the ancester to the Australian nemesiids likely originated in the same mesic habitats.
Molecular phylogenies demonstrate that the Australian and New Zealand Stanwellia have close afinities, suggesting long distance dispersal across the ocean. Ongoing work using molecular clocks will test this hypothesis.

Behaviour

Very little is known about the behaviour of nemesiids.
Females reside in a single burrow for their entire life after hatching and leaving their natal burrow. In this burrow they store food, lay eggs and mate.
Males similarly reside in a single burrow for their entire lives but upon becoming sexually mature, they disperse from their home and seek out adult females in their burrows. Males do not return home but eventually die after mating or while seeking mates.
It is believed that individuals reside in a single burrow and if that burrow is disturbed or damaged, that they cannot rebuild a new burrow.

Method of reproduction

Sexual

Habitat

Terrestrial

Little is known about the specific habitat requirements of many nemesiids. They prefer undisturbed, unmodified landscapes, where they can build their burrows and persist during their long life spans. They are often displaced from locations with an overabundance of invasive weeds, or compacted soils from stock and/or plowing.

Distribution

South Australia

Life Cycle

Juveniles hatch in the mother's burrow and disperse to build their own burrow.
Females will then remain in that burrow for their entire lives.
Males will disperse to find females when sexually mature.
Life spans are uncertain, but individuals could live more than ten years, and sexual maturity could be reached as early as 2-3 years.