Fat Guam partulaThe fat Guam partula or humped tree snail, scientific name Partula gibba, is an endangered species of air-breathing land snail, a terrestrial gastropod mollusk in the family Partulidae.DistributionThis species occurs throughout the Mariana Archipelago, and has been reported in the greatest densities and population sizes on the isle of Sarigan.EcologyOn Sarigan, the species has been recorded most frequently in high-elevation native forests on the trunks of large Erythrina variegata specimens, often resting at the base of branches. On 19 May 2015 specimens were found consuming the Pandanus-fruit ejecta of the Mariana fruit bat on the leaves of a Pandanus tectorius tree. Mariana partulids have been noted to consume plant material, both living and decaying.