Gasteracantha cancriformis
(Spiny-backed Orb-weaver)

Featured spider picture The spider species Gasteracantha cancriformis, commonly known as Spiny-backed Orb-weaver, belongs to the genus Gasteracantha, in the family Araneidae. Gasteracantha cancriformis spiders have been sighted 61 times by contributing members. Based on collected data, the geographic range for Gasteracantha cancriformis includes 7 countries and 10 states in the United States. Gasteracantha cancriformis is most often sighted outdoors, and during the month of May.

Taxonomic Hierarchy

Kingdom: Animalia
Phylum: Arthropoda
Class: Arachnida
Order: Araneae
Suborder: Araneomorphae
Family: Araneidae
Genus: Gasteracantha
Species: Gasteracantha cancriformis

Common Name (AAS)

Spiny-backed Orb-weaver

Other Common Names

Spiny Orb-weaver, Thorn-belly Orb-weaver, Jewel Box Spider, Crab-like Orb-weaver

Author

Carl Linnaeus, 1758

Primary Colors

Sightings Overview

There have been 61 confirmed sightings of Gasteracantha cancriformis (Spiny-backed Orb-weaver), with the most recent sighting submitted on April 8, 2024 by Spider ID member pamsue. The detailed statistics below may not utilize the complete dataset of 61 sightings because of certain Gasteracantha cancriformis sightings reporting incomplete data.

Web: 87% of the time, Gasteracantha cancriformis spiders are sighted in a spider web (Sample size: 61)
Sex: 7 female and 0 male.
Environment: Gasteracantha cancriformis has been sighted 65 times outdoors, and 3 times indoors.
Outdoors: Man-made structure (24). On flower (1). Low foliage (20). High foliage (17). Freshwater river, lake, stream (1). Open field, pasture, grassland (1). Forest (1).

Location and Range

Gasteracantha cancriformis (Spiny-backed Orb-weaver) has been sighted in the following countries: Brazil, Colombia, Ecuador, Honduras, Mexico, Panama, United States.

Gasteracantha cancriformis has also been sighted in the following states: Alabama, Florida, Georgia, Hawaii, Mississippi, North Carolina, South Carolina, Tennessee, Texas, Virginia.

Seasonality

Gasteracantha cancriformis has been primarily sighted during the month of May.

January: 7
February: 4
March: 9
April: 5
May: 11
June: 2
July: 4
August: 4
September: 3
October: 5
November: 3
December: 4

Additional Remarks

The egg sac of this species is a flattened mass of tangled bright yellowish-green silk, often with a thin, vertical stripe of dark green silk on top.
Adult males are smaller than the females and do not have prominent spines like the females do. They still have some “lumpy” protrusions, though.
The shape and length of the spines of the spider may have geographic variations.
The orb web may have tufts of silk sporadically placed on the threads.