Partula is a genus of air-breathing tropical land snails, terrestrial pulmonate gastropod mollusks in the family Partulidae.Myers, P.; Espinosa, R.; Parr, C. S.; Jones, T.; Hammond, G. S. & Dewey, T. A. (2006). The Animal Diversity Web (online). Accessed at http://animaldiversity.org.ITIS Standard Report Page: Partulidae

Many species of Partula are known under the general common names "Polynesian tree snail" and "Moorean viviparous tree snail".Searching for "Partula". In: IUCN 2010. IUCN Red List of Threatened Species. Version 2010.3. <www.iucnredlist.org>. Downloaded on 14 September 2010. Partulids are distributed across of Pacific Ocean islands, from the Society Islands to New Guinea.

Once used as decorative items in Polynesian ceremonial wear and jewelry, these small snails, averaging about in length, gained the attention of science when Dr. Henry Crampton (along with Yoshio Kondo) spent 50 years studying and cataloging partulids, detailing their remarkable array of morphological elements, ecological niches, and behavioral aspects that illustrate adaptive radiation.Jung, Younghun, Taehwan Lee, Burch J. B. & Diarmaid Ó Foighil. (2005) "Historical phylogeny of Tahitian Partula". Proc. Joint Conference - American Malacological Society and Western Society of Malacologists.Gerlach, J. (2016) Icons of Evolution - Pacific island tree snails, family Partulidae. Phelsuma Press, Cambridge

Decline

The partulids of the island of Tahiti act as an example of the possible deleterious effects of attempted biological control. After an infestation of the introduced giant African land snails (Achatina spp.), the carnivorous Florida rosy wolfsnail (Euglandina rosea) was introduced into Tahiti in an attempt to combat the African species.

Instead, the rosy wolfsnail hunted the nearly 76 species of Partula that were endemic to Tahiti and the nearby islands, causing all but 12 species to go extinct within a decade. Scientists were able to save 12 of these species prior to their becoming extinct.

Today, the Zoological Society of London runs the Partula Programme Consortium which maintains a captive-breeding programme in the United Kingdom, France, and the United States.

As of the 2024 update released on June 27, the IUCN Red List of Threatened Species contains 73 Partula species. Of these, 32 are listed as extinct, 10 are extinct in the wild, 17 are critically endangered, 8 are endangered, 2 are vulnerable, and only 4 species are least concern.

Individuals are being reintroduced to Tahiti from captive breeding programmes since 2014. In April 2023, over 5,000 individual snails from zoos in the United States and the United Kingdom were released on Tahiti and Mo'orea.

Species Species within the genus Partula include:

Full list The species pages are currently outdated because of the IUCN 2024-1 update. The list may be currently missing some species. If you notice a missing species please add it. SpeciesSPCNotesPartula affinisCR1A single population persists on Tahiti Iti but reasonable numbers exist in captivity.Partula argutaPE0The last captive individual died in 1994.Partula assimilisCR1Threatened by habitat loss, though currently relatively free of predators.Partula atilisEX0Partula auranianaEN5Extirpated from its type locality in Aore Island but persists in the Torres Islands.Partula aurantiaEX0The last captive individual died in the 1980s.Partula auriculataEX0Could not be located after 1991. Old shells were found in 1994.Partula bilineataEX0Could not be located after 1993.Partula claraCR20Has become much rarer but several populations persist.Partula clarkeiEX0Last captive individual died in 1996.Partula compressaPE1One population photographed in 2004.Partula cooteiEX0Outcompeted by Partula hyalina. Old shells found in 2005.Partula cramptoniCR1Extirpated from Rennell Island, though survives in Bellona Island.Partula crassilabrisEX0Partula cuneataEX0Could not be located in the 1992 survey.Partula cythereaPE1Isolated population on Mt. Marau confirmed in 2005.Partula dentiferaEX0Only dead shells could be found in the 1991 survey.Partula desolataN/A0Fossil species.Partula diminutaEX0Could not be located after 1980.Partula dolichostomaEX0Could not be located after 1980.Partula dolorosaEX0Could not be located after 1992.Partula emersoniCR2Currently only known from a dead subadult in one location and a live one in another.Partula eremitaEX0Could not be located after 1980.Partula fabaEX0The last captive individual died in 2016.Partula flexuosaLC?Tolerant of current levels of disturbance and predators.Partula garrettiiEW0Partula gibbaEN4Persists in Guam, Sarigan, Pagan and Saipan. Extinct on Aguiguan.Partula griseaLC?All populations appear to be tolerant of threats.Partula guamensisEX02005, 2006 and 2008 surveys found only 4 old, eroded shells.Partula hebeEW0Partula hyalinaVU1-5Wild populations may be recovering.Partula incrassaCR1All individuals are hybrids with Partula clara.Partula jackieburchiPE1May survive on Mt. Aorai.Partula labruscaEX0The last captive individual died in 2002.Partula laevigataPE1One population may survive in central Tahiti.Partula lanceolataEN3Endemic to Mago, Cicia and Naiau.Partula langfordiEX0Not located in 1992.Partula leefeiCR1Survival confirmed from a single individual.Partula leptochilaEX0Could not be located after 1980.Partula levistriataEX0Could not be located after 1980.Partula lirataEN11Many populations are unstable and inviable in the long-term.Partula lugubrisEX0Could not be located in the 1990s.Partula lutaensisN/A?Endemic to Rota. Little is known about this species.Partula luteaEX0Only species found in Bora Bora. Could not be located in 2006 or 2017.Partula magistriEX0Only known from a single specimen.Partula makateaN/A0Fossil species.Partula meyeriPE1Only known from a single location. Not seen since its discovery in 2005.Partula micansLC?No major threats to this species are known.Partula mirabilisEW0Partula mooreanaEW0Partula navigatoriaEW0Partula nodosaEW0Partula obesaCR2Endemic to Alofi and Futuna. Population declined severely in both islands.Partula otaheitanaEN5-10Survives in populations above 950m altitude and in one population on Tahiti Iti.Partula pacificaVU6-10Endemic to nine islands. Eliminated from Espiritu Santo and Aore, the island of "Yatalo" remains unidentified and the other six islands have not been surveyed.Partula pearcekellyiEX0Single valley endemic. A single shell was found in 1992.Partula planilabrumEX0Could not be located in 1994.Partula productaEX0Could not be located after 1980.Partula protractaEX0Could not be located after 1980.Partula pyramisEN4-5Type population is almost certainly extinct. Remaining populations have not been surveyed.Partula radiolataEN1Only one population remains. Viable but vulnerable.Partula radiosaEN1-2Little is known about this species. May already be extinct.Partula remotaEX0Could not be located after 1980.Partula roseaEW0Partula rufaPE1Not located after 1936.Partula sagittaEX0Could not be located after 1990.Partula salifanaEX0Dead shells were found in 1989.Partula similarisLC?Tolerant of habitat loss and free of predators.Partula suturalisEW02/2 subspecies survive.Partula taeniataCR23/4 subspecies survive.Partula tohiveanaCR1Wild-born individuals have become more and more common in recent years, suggesting a population is established. First invertebrate species to be downgraded from EW to CR on the IUCN Red List.Partula tristisEX0Could not be located after 1990.Partula turgidaEX0Last captive individual died in 1992.Partula umbilicataEX0Could not be located after 1980.Partula vanikorensisCR1Endemic to Vanikoro.Partula variaEW0

Collected for ex situ conservation The Partula that were collected for ex situ breeding include the following:

Tahiti – P. affinis, P. clara, P. compressa (P. otaheitana), P. hyalina, P. nodosa

Moorea – P. aurantia, P. mirabilis, P. mooreana, P. suturalis, P. taeniata, P. tohiveana

Huahine – P. arguta, P. rosea, P. varia

Raiatea – P. clarkei (P. turgida), P. dolorosa, P. faba, P. garrettii (P. tristis), P. hebe, Partula labrusca, P. navigatoria (P. dentifera)

Marianas – P. gibba, P. lutaensis (P. langfordi)

P. garrettii and P. navigatoria were misidentified as the species in parentheses next to them.

Surviving species The list of surviving species are as follows:

Tahiti – P. affinis, P. clara, P. hyalina, P. incrassa, P. nodosa, P. otaheitana

Moorea – P. mirabilis, P. mooreana, P. suturalis, P. taeniata, P. tohiveana

Huahine – P. rosea, P. varia

Raiatea – P. garrettii (P. tristis), P. hebe, P. meyeri, P. navigatoria (P. dentifera)

Marianas – P. gibba, P. lutaensis, P. radiolata

Micronesia – P. emersoni

Fiji – P. leefei, P. lirata

Solomon Islands – P. cramptoni, P. micans

Papua New Guinea – P. auraniana, P. similaris

Cook Islands – P. assimilis

Cladogram Phylogenetic analyses revealed that many of the Partula species are not monophyletic. The resulting cladogram is shown below.

Ecology Partula species on Tahiti were usually found on the undersides of the leaves of Caladium and plantain, although in some valleys, they were frequently found on Dracaena and turmeric. Gallery

Tahitian species

Moorean species

Huahine species

Raiatean species

Mariana Islands species

References This article incorporates public domain text from the reference.Mayer A. G. (January 1902). "Some species of Partula from Tahiti. A study in variation". Memoirs of the Museum of Comparative Zoölogy XXVI(2), Cambridge, U.S.A.

Further reading Crampton H. E. (1916). Studies on the variation, distribution and evolution of the genus Partula. The species inhabiting Tahiti. Carnegie Institution of Washington, 228: 1-311. Crampton H. E. (1925). Studies on the variation, distribution and evolution of the genus Partula. The species of the Mariana Islands, Guam and Saipan. Carnegie Institution of Washington, 228a: 1-116. Crampton H. E. (1932). Studies on the variation, distribution and evolution of the genus Partula. The species inhabiting Moorea. Carnegie Institution of Washington, 410: 1-335.

External links

Partula evolution, diversity and conservation Partula Pages