CoP17 Prop. 49

Inclusion of all species of Cuban land snails in the genus Polymita in Appendix I
Proponent: Cuba
Summary: The genus Polymita, commonly known as Cuban land snails, contains six species; P. brocheri,
P. muscarum, P. picta (the largest species of the genus), P. sulphurosa, P. venusta and P. versicolor. All areendemic to Cuba. They are arboreal and adapted to live on a variety of plants including coffee trees andcoconut palms. Shell size is 2 to 3cm. In the wild, Polymita are estimated to live between 12 and 19 months,
reaching sexual maturity at between nine and ten months. Clutch size varies, but is generally from 30 to 100
or more. Individuals (which are hermaphrodite) breed only once.
The shells of Polymita are beautiful with a wide range of colours, and are sold as handicrafts (such asnecklaces) or to shell collectors.
Potential distribution maps (provided in the Supporting Statement) for each species have been calculated
based on known distribution maps that have had suitable habitat that no longer exists and extirpatedsub-populations removed; these provide the basis for the estimated of area of distribution provided below.
Polymita brocheri has a current distribution estimated at just over 50km 2 of fragmented habitat; original
distribution is estimated at ca. 70km2 (ca. 30% reduction). Population can reportedly be locally abundant(3.5 individuals per m 2); density overall has been calculated at 0.1 individuals per m 2 1. It is reported to be
used domestically for fishing bait1. Not known to be present in any protected area3.
Polymita muscarum has a current distribution estimated at ca. 3600km 2; original distribution is estimated at
ca. 8000km2 (56% reduction). Population size is unknown. Inland populations have reportedly been greatlyreduced or have disappeared and the species is now largely confined to a narrow strip of coastal vegetation
where development for tourism has led to habitat fragmentation. In 22 coastal towns the population was at avery low density (0.002 to 0.3 individuals per m 2). Known to occur in at least one protected area3.
Polymita picta has a current distribution estimated at ca. 2200km2, marginally reduced from the estimatedoriginal distribution (ca. 2400km2). Population size is unknown. Surveys of 39 localities found an averagedensity of between 0.01 and one individual per m2 1. Populations not targeted for harvest had higher reported
densities than unexploited populations4 but it is not clear whether this was due to surveys taking place at
different times of the year, or a genuine indication of harvesting impact. Local extinctions of populations havebeen reported1. The species is not present within any protected areas3 and it is impacted by habitat
modification and fragmentation, as well as pesticide use in coffee plantations which is known to have caused
a mass die-off in one plantation1.
Polymita sulphurosa is believed to have an extremely limited distribution, potential habitat within its range
comprising patches totalling a few square kilometres (there are differing estimates of 1.3 to 2.5km2 andca. 7km2)2, 3. Original range has been estimated at ca. 200 km2 (98% reduction). Remaining habitat suffers asevere level of fragmentation. Studies conducted from 1995 to 2004 at different times of year foundpopulations at only 25% of localities reported in the literature. Reported densities are low (estimates of 0.08
to 0.4 and 0.001 to 0.1 individuals per m 2 1). An expedition in 2015 located only one individual in one patch of
1.31km2. Habitat is impacted by intense land use for sugarcane agriculture, livestock grazing andsubsistence crops. Depleted populations are believed to be at risk from over-harvest, continuous habitat
fragmentation and incidental killings4. The species is not present in any protected areas3.
Polymita venusta has a current distribution estimated at ca. 8000km 2 and the habitat is fragmented; original
distribution is estimated at ca. 20,000km2 (ca. 60% decrease). Studies at three sites found population density
to fluctuate greatly over time. In some areas only relict populations are found, in areas of low agriculturalinterest. Known to occur in at least one protected area 3.
Polymita versicolor has a current distribution estimated at ca. 100km2 and the habitat is fragmented;
original distribution is estimated at ca. 130km2 (ca. 25% decrease). Average population density at fourlocations has been estimated at 0.02 individuals per m 2 1. Local extinctions have been reported, ascribed tochanges in land use for agriculture, gypsum mining, grazing and housing development and, in one case,possibly to over-collection. Known to occur in at least one protected area3.
International exports were reported in the 1940s to be high (estimated at 0.5 million per year), and although
an export ban (domestic and international trade prohibited without licenses) was introduced in 1943, trade1

CoP17 Prop. 49
continued to the USA and Canada until the 1960s. In the last 20 years, only two legal exports have beenrecorded (55 shells and 35 live specimens). Between 2012 and 2016, Cuban Customs made 15 seizures
totalling more than 23,400 shells being exported to the USA. One expert noted that the bulk of the trade goesto Europe and from there to Asia4.
Species that are illegally traded in the greatest numbers are said to be P. picta, P. sulphurosa, P. versicolorand P. venusta, although all species can be found in international trade, and the most attractive and variedmorphs are selected for harvest1. Most international trade is in fresh shells taken from the wild, rather thanrecycled from old collections1,4, and the main demand now is said to be from tourists1. Collectors will gather
live snails and empty shells when harvesting1: it is not clear what proportion of shells is from live snails. The
majority of live snails are collected before they reach maturity1, 5.
Polymita brocheri has a distinctive shape to its shell, which differs from that of the other species. Some of theother species have distinctive patterning and colouration, making them relatively easy to identify, but in somespecies (e.g. P. venusta and P. picta) there is considerable intraspecific variation, so that enforcement
agents may have difficulty identifying specimens to species level with confidence 5, 6. Photographs to facilitate
their identification are available.
Analysis:
Polymita sulphurosa has a very limited and fragmented range in which it appears to be rare, with evidenceof marked historic decline in area of distribution. It would appear to meet the biological criteria for inclusion in
Appendix I.
Polymita brocheri (52km2) and P. versicolor (99km2) have relatively small ranges. An average population
density of 0.1 individuals per m 2 (equivalent to 100,000 per km 2) has been estimated for P. brocheri and of
0.02 individuals per m 2 (equivalent to 20,000 per km 2) for P. versicolor. Even if these species are only foundat these densities in a portion of their ranges, these figures indicate that their populations are not small.
Declines in population have been deduced largely on the basis of reduction in available habitat, butindications are that these declines have not been marked in the sense of Res. Conf. 9.24 (Rev. CoP16).
These species would not appear to meet the biological criteria for inclusion in Appendix I in Annex 1 ofRes. Conf. 9.24 (Rev. CoP16).
The three remaining species, P. muscarum and P. venusta. P. picta, have relatively extensive areas ofdistribution (2200 to 8000km2) and, on the basis of population density figures, very large populations. All arebelieved to have undergone population declines largely as a result of declines in available habitat, but theseare unlikely to be near the guidelines in Annex 1 of Res. Conf. 9.24 (Rev. CoP16) (in this case a reduction of50% or more in ten years, generation time being ca. one year). These species would not appear to meet thebiological criteria for inclusion in Appendix I in Annex 1 of Res. Conf. 9.24 (Rev. CoP16).
All species are potentially affected by trade (which is illegal) and therefore appear to meet the trade criterion
for inclusion in Appendix I.
Reviewers: R. Kramer.
References:
Information not referenced in the Summary section is from the Supporting Statement.
1 Hernández, N. (2016) In litt. to the IUCN/TRAFFIC Analyses Team, Cambridge, UK.
2 Perez, E., Osa, E., Matamoros, Y., Shillcox, J. & Seal, U.S. (1998) Conservation Breeding Specialist Group(SSC/IUCN). Report of Conservation Assessment and Management Plan Workshop For Selected Cuban Species: Cbsg,Apple Valley, Minnesota 55124, USA.
3 Mauriño, E. R. (2001) Proyecto de investigación - Ecología y conservación del molusco gasterópodo Polymita
sulphurosa en Cuba. Cuadernos de biodiversidad. 7:14-17.
4 González, A. (2016) In litt. to the IUCN/TRAFFIC Analyses Team, Cambridge, UK.
5 Torres, M.M. (2016) In litt. to the IUCN/TRAFFIC Analyses Team, Cambridge, UK.
6 Cowie, R. (2016) In litt. to the IUCN/TRAFFIC Analyses Team, Cambridge, UK.

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