About Gasteracantha mengei Keyserling, 1864
Female Gasteracantha mengei spiders have distinct physical features that separate them from most other species in their genus. Unlike most other Gasteracantha species, which typically have three pairs of abdominal spines, female Gasteracantha mengei have only two pairs of abdominal spines and completely lack the rear spines found on other members of the genus. Their abdomen is flat, dark brown, and measures more than twice as wide as it is long, with an average width of around 12.5 mm and an average length of around 5.5 mm. Of the two spine pairs, the larger median spines are tapered, angled slightly backward, and each reaches close to 5 mm in length. The smaller anterior spines are between one-third and one-half the length of the larger median spines, and are oriented parallel to these larger spines. When exposed to ultraviolet light, the upper surface of the abdomen glows with a blue-green fluorescence.
