Sphaerodactylus ariasae is one of the smallest members of the Gekkonidae family and at an adult length of 16-18mm can curl up on a US dime. They are endemic to Hispaniola and can be found in leaf litter near limestone caves or cliffs.
S. ariasae shares the title of smallest of the amniote vertebrates, which are the reptiles, birds, and mammals, with S. parthenopion from the British Virgin Islands. These geckos are thought to be at the lower physiological limit for reptiles. Their large surface area to volume ratio makes them particularly susceptible to dehydration.
S. ariasae is named for Yvonne Arias, a champion for conservation in the Jaragua National Park, an important habitat for these geckos. They are threatened by deforestation, despite efforts to protect the park.