Theotima minutissimus

Photo of the Theotima minutissimus

Theotima minutissimus (Sci.), native, Puerto Rico. Caribbean Islands, the Philippines, Borneo, Sumatra, Indonesia, Thailand and Guam.

Photo Robert L. Edwards. Information compiled by Alan Mowbray, Interpretive Media Writer, EYNF/LEF

General Information

Class-Araneae, Family- Ochyroceratidae, Genus-Theotima. Species-minutissimus. Over the years, only female specimens of this minute rain forest spider have been collected; never male!

Description

This tiny, six-eyed spider measures only 0.03 inches (0.9 millimeters) in total body length. T. minutissima has a black body with eight grayish black legs.

Habits

There is very little information available that describes the life history of these spiders. No males have been discovered so far, leading to speculation that the female of the species is parthenogenetic (it doesn’t require a male to produce fertile eggs) after producing eggs, female T. minutissimus carry them in a bundle in their chelicerae (fanglike appendages near the mouth) until they hatch. Eggs remain attached to a silk pad spun by the mother until the spiderlings are fully developed and capable of moving about on their own. Each “clutch” of eggs contains from 1 to 9 oval, translucent eggs. Approximately 3 weeks after emerging from their mother, when thorax, abdomen and legs have formed, they engage in what appears to be “push-ups,” flexing their legs and pushing away from their mother and shedding their first exoskeletons.

Habitat

Theotima minutissimus is abundant in the El Yunque National Forest, Its preferred habitat is litter composed of smaller leaves in second growth forests with understory shrubs or in those forests with damper and more easily decayed leaves such as mahogany (Swietenia macrophylla) or bamboo (Bambusa vulgaris). T. minutissimus prefers elevations less than 2,624 feet (800 meters).

Habitat density has been measured at between 46 and 166 individual spiders per square meter!

Where to look for this animal in the EYNF

In leaf litter, near locations trails below 2,000 foot elevation, such as the El Portal nature trail and the lower section of the Big Tree nature trail.





https://www.fs.usda.gov/detail/elyunque/learning/nature-science/?cid=fsbdev3_042916