Partula

Partula is a genus of land snails, constituting over 100 species of arboreal land snails native to French Polynesia and neighboring islands.

Their decline and extinction is the result of failed biological control. The giant African land snail was introduced to French Polynesia as a food source, which escaped and began destroying crops. The rosy wolfsnail was subsequently introduced to eat and eradicate the giant African land snail. It instead chose to eat the 100 species of Partula endemic to the islands, resulting in an accidental mass extinction event within French Polynesia.

Some species were successfully saved by scientists who collected the last live individuals from French Polynesia and took them into captivity for breeding. Others have been resilient enough to survive in the wild.

Notable species

Partula affinis, which survived in a valley the rosy wolfsnail never reached. It is believed to be a closely related species to Partula otaheitana.

Partula clara, which continues to survive in some areas.

Partula exigua, the first species of Partula to become extinct, a predatory snail itself which ate other native snails. These prey snails' populations increased after its extinction. It was named for being the smallest Partula species.

Partula faba, the first species of Partula to be described, which was taken into capitivity but failed to breed. The last died in 2016.

Partula hebe, which is a successfully bred species. The last 9 snails were collected and bred, and have been reintroduced to the wild over 20 years later.

Partula hyalina, which is an extremely resilient species. It continues to survive in the prescence of the rosy wolfsnail as well as on several islands the rosy wolfsnail was not introduced to.

Partula otaheitana, the second Partula species to be described, after Partula faba. Closely related to Partula affinis.

Partula rosea and Partula varia, two species native to Huahine. These two species were used by the natives to make jewelry. Both were successfully taken into captivity and released some time after.

Partula suturalis and Partula taeniata, previously considered extinct but now considered extant because of taxonomic changes. Initially they were each confined to one subspecies, P. s. suturalis and P. t. taeniata, both extinct, but since then other species have been demoted to subspecies under these two species, resulting in their "de-extinction".

Partula turgida, the first known extinction due to a parasite. Was taken into the breeding program but all snails were killed by a parasite that infested the breeding chamber.

Surviving species

This is a complete list of the surviving species.

Surviving Partula species

Island	Species	IUCN	Status
Tahiti	Partula affinis	Critically Endangered	Reintroduction supported
	Partula clara	Critically Endangered	Relict
	Partula hyalina	Vulnerable	Reintroduction supported
	Partula nodosa	Extinct in the Wild	Reintroduced
	Partula otaheitana	Critically Endangered	Relict
Moorea (Mo'orea)	Partula mirabilis	Extinct in the Wild	Reintroduced
	Partula mooreana	Extinct in the Wild	Reintroduced
	Partula suturalis	Extinct in the Wild	Reintroduced
	Partula taeniata	Critically Endangered	Reintroduction supported
	Partula tohiveana	Extinct in the Wild	Reintroduced
Huahine	Partula rosea	Extinct in the Wild	Reintroduced
	Partula varia	Extinct in the Wild	Reintroduced
Raiatea	Partula garrettii	Extinct in the Wild	Reintroduced
	Partula hebe	Extinct in the Wild	Reintroduced
	Partula navigatoria	Extinct in the Wild	Reintroduced

Reintroductions

P. garrettii was misidentified as P. tristis for some time, and P. navigatoria was misidentified as P. dentifera.

Partula reintroductions

Species	IUCN	2015	2016	2017	2018	2019	Total
Tahiti
Partula affinis	CR	48	201	129	240	182	800
Partula hyalina	VU	1	8	90	71	12	182
Partula nodosa	EW	220	877	1,777	-	2,528	5,402
Moorea
Partula mirabilis	EW	-	-	-	10	60	70
Partula mooreana	EW	-	592	344	-	-	936
Partula suturalis strigosa	EW	-	-	-	-	-	0
Partula suturalis vexillum	EW	-	374	290	171	210	1,045
Partula taeniata nucleola	CR	-	100	206	201	219	726
Partula taeniata simulans	CR	-	67	-	549	360	976
Partula tohiveana	EW	-	639	950	766	710	3,065
Huahine
Partula rosea	EW	-	-	-	-	1,896	1,896
Partula varia	EW	-	-	-	-	522	522
Raiatea
Partula garrettii	EW	-	38	-	-	-	38
Partula hebe	EW	-	81	-	-	-	81
Partula navigatoria	EW	-	96	-	-	-	96

Species list

All species of Partula within the Society Islands are listed here, sorted by island:

Society Islands

Tahiti

1. Partula affinis
2. Partula clara
3. Partula compressa
4. Partula cytherea
5. Partula diminuta
6. Partula hyalina
7. Partula incrassa
   1. Partula incrassa exigua
   2. Partula incrassa incrassa
8. Partula jackieburchi
9. Partula laevigata
10. Partula nodosa
11. Partula otaheitana

Moorea

1. Partula aurantia
2. Partula mirabilis
3. Partula mooreana
4. Partula suturalis
   1. Partula suturalis strigosa
   2. Partula suturalis vexillum
5. Partula taeniata
   1. Partula taeniata elongata
   2. Partula taeniata nucleola
   3. Partula taeniata simulans
6. Partula tohiveana

Huahine

1. Partula arguta
2. Partula rosea
3. Partula varia

Tahaa

1. Partula bilineata
2. Partula eremita
3. Partula planilabrum
4. Partula sagitta
5. Partula umbilicata

Bora-Bora

1. Partula lutea