cobweb spiders vs Coiban Mastuff Bat

Steatoda grossa compared with Molossus coibensis

Taxonomic Classification

Rank	cobweb spiders	Coiban Mastuff Bat
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum	Arthropoda (Arthropods)	Chordata (Chordates)
Class	Arachnida (Arachnids)	Mammalia (Mammals)
Order	Araneae (Araneae)	Chiroptera (Bats)
Family	Theridiidae	Molossidae
Genus	Steatoda	Molossus
Species	Steatoda grossa	Molossus coibensis

Evolutionary Relationship

cobweb spiders and Coiban Mastuff Bat share a common ancestor at the Kingdom level: Animalia. (Animals)

Conservation Status

cobweb spiders

LC — Least Concern

Coiban Mastuff Bat

LC — Least Concern

Physical Characteristics

Attribute	cobweb spiders	Coiban Mastuff Bat
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

cobweb spiders

Habitat

Typically found in terrestrial habitats from forests to deserts.

Range

Widely distributed across Africa (South Africa), Europe (29 countries), North America (Canada, United States), and South America (Ecuador).

Coiban Mastuff Bat

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Range

Distributed across Colombia, Ecuador, and Venezuela.

cobweb spiders

The false black widow (Steatoda grossa) is a cosmopolitan cobweb spider in the family Theridiidae, often mistaken for the true black widow due to its similarly dark, globose abdomen, though it lacks the red hourglass marking. Females reach 6–10 millimeters in body length and display a deep purplish-brown to nearly black coloration with faint pale markings on the dorsal abdomen. Originally native to western Europe, Steatoda grossa has spread globally through human commerce, establishing populations in Australia, New Zealand, North America, and other regions where it thrives in human structures including homes, sheds, and outbuildings. The spider constructs a persistent, tangled cobweb in sheltered corners and recesses, where it captures woodlice, ants, beetles, and other arthropods—notably targeting invertebrates that many other spiders avoid. The venom of S. grossa causes steatodism, a syndrome of localized pain, sweating, and systemic discomfort that is rarely serious but can cause significant distress. Interestingly, the antivenin produced for Latrodectus (true widow) spider bites has been shown to effectively treat Steatoda envenomations, underscoring the phylogenetic relatedness of these genera. Females produce several egg sacs during a season, each containing dozens of eggs wrapped in distinctive silken cocoons. The species is classified as Least Concern given its expanding global distribution facilitated by human activity.

Coiban Mastuff Bat

The Coiban Mastuff Bat (Molossus coibensis) is a small free-tailed bat in the family Molossidae, named for Coiba Island off the Pacific coast of Panama, where specimens were first collected. Members of the genus Molossus are robust, fast-flying insectivores adapted to open-air foraging above the forest canopy and over water, characterised by narrow wings and a tail that extends beyond the patagium (wing membrane). Molossus coibensis inhabits lowland tropical forests and adjacent open habitats in Central America and northwestern South America, with confirmed records from Colombia, Ecuador, Venezuela, and Panama, indicating a distributional range that extends well beyond its type locality on Coiba Island. Like other mastiff bats, it roosts in crevices within buildings, rock faces, and hollow trees, emerging at dusk to pursue aerial insects at speed. The species feeds primarily on large beetles, moths, and other night-flying insects, typically hunted high above the forest. It is assessed as Least Concern by the IUCN based on its relatively wide range and tolerance of modified habitats. Molossus coibensis was long treated as a subspecies of Molossus molossus before being recognised as a distinct species based on morphological and molecular evidence. Ecological and life-history data specific to this taxon remain limited.

Shared Countries

Both species can be found in 1 countries:

🇪🇨 Ecuador