Definition Segestrioides is a genus of spiders belonging to the family Filistatidae. These spiders are characterized by their cribellate silk and are classified within the Araneomorphae suborder.
Overview The genus Segestrioides was formally described by the Italian arachnologist Paolo Marcello Brignoli in 1984. It encompasses a small number of recognized species. Members of this genus are primarily distributed in specific regions of South America, including countries such as Brazil, Peru, and Chile. As part of the Filistatidae family, they are commonly referred to as "crevice weavers" or "lampshade spiders," although Segestrioides itself does not have a unique widely recognized common name. Its establishment contributed to the understanding of spider taxonomy and biodiversity in Neotropical regions.
Etymology/Origin The name Segestrioides is derived from the established spider genus Segestria (family Segestriidae) combined with the Greek suffix "-oides," meaning "resembling" or "having the form of." This nomenclature suggests a morphological similarity or superficial resemblance to spiders of the Segestria genus, despite Segestrioides belonging to a distinct family, Filistatidae. The genus was established during Brignoli's extensive work on spider taxonomy, following the collection and examination of specimens from South America.
Characteristics Spiders within the genus Segestrioides exhibit characteristics typical of the Filistatidae family and cribellate spiders:
- Cribellum: They possess a cribellum, a specialized spinning organ located anterior to the spinnerets, which produces a fine, woolly, non-sticky silk composed of thousands of extremely thin fibers. This unique silk is effectively used to entangle prey through electrostatic and mechanical adhesion, similar to Velcro.
- Eyes: Like other Filistatidae, Segestrioides spiders typically have eight eyes, which are often arranged in a compact, somewhat anteriorly-facing group.
- Habitat: They are generally found in sheltered environments, such as rock crevices, under bark, or within other protected nooks, consistent with their "crevice weaver" designation. This preference for retreats often influences their web architecture.
- Webs: They construct irregular, often funnel-like retreat webs made from their characteristic cribellate silk. These webs typically lack adhesive glue but are highly efficient in snaring insects due to the complex structure of the cribellate silk.
- Size and Appearance: They are typically small to medium-sized spiders. Specific coloration and morphology vary between individual species within the genus, though many are cryptic, blending into their environment.
Related Topics
- Filistatidae: The family to which Segestrioides belongs, known for their cribellate silk and crevice-dwelling habits.
- Araneomorphae: The suborder of "true spiders," encompassing the vast majority of extant spider species, to which Segestrioides belongs.
- Cribellate Spiders: A functional group of spiders characterized by the presence of a cribellum for silk production, which contrasts with ecribellate spiders that produce sticky silk.
- Arachnology: The scientific study of arachnids, including spiders, within which the genus Segestrioides is a taxonomic unit.
- Taxonomy: The scientific classification of organisms, particularly relevant in defining and describing genera like Segestrioides based on morphological and genetic characteristics.
- Segestria: A genus of spiders (family Segestriidae) from which the name Segestrioides derives its root, indicating a historical or perceived morphological connection in spider classification.