Theridion grallator is a species of spider in the genus Theridion that is found exclusively in Hawaii.
The underside is light yellow and somewhat transparent.
Depending on the food consumed, it can be red, black, and white in color.
T. grallator gets its name from its long, spindly legs (grallator meaning “stilt-walker” in Latin).
It gets the nickname happy-face spider because of the yellow color on most of the body and the patterns on the abdomen.
The pattern is similar to a smiling face.
Therefore the common English name is also “happy face spider”.
This polymorphism could counteract the applicability of their hunters’ prey schemes.
The females live as solitary animals under leaves in forests.
They defend their egg balls aggressively and look after the brood for a while after they hatch.
It can happen that some young animals of the brood are taken in by foster mothers.
They mostly live predatorily and feed mainly on captured arthropods, especially insects that they suck out.
For this purpose, the prey animals are first dissolved with an enzyme-containing digestive juice, which the spider brings into its victim, which has been killed with its jaw claws.
It is absolutely harmless to humans.
Despite its restricted habitat, the Theridion Grallator is not considered endangered according to the IUCN
Text: Together for the animals
Not all happy-face spiders have such striking markings, and some are nearly all orange or all blue.
The Hawaiian name is nananana makakiʻi (face-patterned spider).
In addition to the variety of color polymorphisms present in T. grallator, this spider also demonstrates the interesting quality of diet-induced color change, in which its appearance temporarily changes as it metabolizes various food items.
T. grallator spiders do not utilize webs to capture prey, so they do not follow the sit-and-wait method of web-building spiders. Instead, they will forage freely, often traveling to nearby leaves to capture insects.
During prey capture, T. grallator spiders use their silk.
Common prey include Dolichopodidae and Drosophilidae.
A very likable animal and a splendid specimen of the genus!
My best regards to all, Venus