cobweb spiders vs Delfín tonina

Steatoda grossa compared with Tursiops truncatus

Taxonomic Classification

Rank	cobweb spiders	Delfín tonina
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum	Arthropoda (artrópodos)	Chordata (cordados)
Class	Arachnida (arácnidos)	Mammalia (mamíferos)
Order	Araneae (araña)	Cetacea (Whales & Dolphins)
Family	Theridiidae	Delphinidae (Oceanic Dolphins)
Genus	Steatoda	Tursiops (Bottlenose Dolphins)
Species	Steatoda grossa	Tursiops truncatus

Evolutionary Relationship

cobweb spiders and Delfín tonina share a common ancestor at the Kingdom level: Animalia. (Animals)

Conservation Status

cobweb spiders

LC — Least Concern

Delfín tonina

LC — Least Concern

Population: ~600.0K

Trend: Stable →

Physical Characteristics

Attribute	cobweb spiders	Delfín tonina
Diet	—	Carnivore
Average Lifespan	—	45 years
Average Length	—	3.0 m
Average Weight	—	300.0 kg

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).

Delfín tonina

Habitat

Found across multiple habitat types including tropical and subtropical moist broadleaf forests, tropical and subtropical dry broadleaf forests, and tropical and subtropical grasslands and savannas, among 12 distinct biome types. Populations are also found in montane and highland environments at higher elevations.

Range

Widely distributed across Asia (Taiwan), Europe (6 countries), and South America (Colombia, Ecuador, 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.

Delfín tonina

La especie de delfín más estudiada y reconocida, los delfines mulares habitan océanos cálidos y templados de todo el mundo, desde las aguas costeras poco profundas hasta el mar abierto. Altamente inteligentes con grandes cerebros en relación con el tamaño corporal, demuestran autoreconocimiento, comunicación compleja y aprendizaje social. Viven en sociedades fluidas de fisión-fusión y cooperan para arrear peces. Una especie indicadora clave de la salud del ecosistema marino.

Shared Countries

Both species can be found in 6 countries:

🇧🇪 Belgium 🇩🇰 Denmark 🇪🇨 Ecuador 🇵🇹 Portugal 🇸🇪 Sweden 🇺🇦 Ukraine