''Partulina redfieldi'' is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

tropical The tropics are the regions of Earth surrounding the equator, where the sun may shine directly overhead. This contrasts with the temperate or polar regions of Earth, where the Sun can never be directly overhead. This is because of Earth's ax ...

air-breathing

land snail A land snail is any of the numerous species of snail that live on land, as opposed to the sea snails and freshwater snails. ''Land snail'' is the common name for terrestrial molluscs, terrestrial gastropod mollusks that have gastropod shell, shel ...

, a

terrestrial Terrestrial refers to things related to land or the planet Earth, as opposed to extraterrestrial. Terrestrial may also refer to: * Terrestrial animal, an animal that lives on land opposed to living in water, or sometimes an animal that lives on o ...

pulmonate Pulmonata or pulmonates is an informal group (previously an order, and before that, a subclass) of snails and slugs characterized by the ability to breathe air, by virtue of having a pallial lung instead of a gill, or gills. The group inclu ...

gastropod Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and fro ...

mollusk Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The ...

in the family

Achatinellidae Achatinellidae is a family of tropical air-breathing land snails, terrestrial pulmonate gastropod mollusks in the superfamily Pupilloidea. Taxonomy It was previously the only family in the superfamily Achatinelloidea (according to the tax ...

Description and biology

''Partulina redfieldi'' appears in various colors, and the shells are found to be polymorphic, exhibiting a wide range of white to brown shades with varying numbers of white or brown bands. ''Partulina redfieldi'' must reach 3 to 5 years of age before it can reproduce and are only capable of producing up to 5 babies every year. The snail has a juvenile mortality rate of 42%.

Distribution and habitat

''Partulina redfieldi are''

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to the island of

Molokai Molokai or Molokai ( or ; Molokaʻi dialect: Morotaʻi ) is the fifth most populated of the eight major islands that make up the Hawaiian Islands archipelago in the middle of the Pacific Ocean. It is 38 by 10 miles (61 by 16 km) at its g ...

Hawaii Hawaii ( ; ) is an island U.S. state, state of the United States, in the Pacific Ocean about southwest of the U.S. mainland. One of the two Non-contiguous United States, non-contiguous U.S. states (along with Alaska), it is the only sta ...

. This species is commonly found on the smooth leaves of the ‘ohi’a lehua tree or

metrosideros polymorpha ''Metrosideros polymorpha'', the ''ōhia lehua'',; is a species of flowering evergreen tree in the Myrtus, myrtle family, Myrtaceae, that is Endemism, endemic to the six largest Hawaiian Islands, islands of Hawaii, Hawaii. It is a member of the ...

, also endemic to the Hawaiian Islands.

Population decline

From 1983 to 1995, the general population of ''Partulina redfieldi'' grew significantly from 100% to 900%. Since 1995, the population has decreased by 85%, due to rat predation, which has shown itself to be a growing threat to tree snail species endemic to Hawaii. ''Partulina redfieldi'' population initially decreased by 85% within just 2 years of being discovered by rats.

References

Endemic fauna of Hawaii Partulina Biota of Molokai Gastropods described in 1853 Taxonomy articles created by Polbot {{Achatinellidae-stub