Monday, March 21, 2016








By José Leal

Join us to examine the threats faced by the world’s second most diverse group of animals

On May 22–24, 2016 the Bailey-Matthews National Shell Museum on Sanibel Island, Florida, will host a conference devoted to the threats to the second most diverse group of animals on Earth.

The 2.5 day Mollusks in Peril forum will bring together the country’s foremost experts on current large-scale threats to molluscan populations to discuss, through presentations and panels, the challenges facing mollusks. 

As our planet is subjected to unprecedented rates of human-induced environmental change, populations of mollusks inhabiting a wide range of habitats are being exposed to exceptional amounts of ecological stress. These stressors include, but are not limited to, alterations caused by climate change and other large-scale environmental disturbances. 

Mollusks in Peril will facilitate an in-depth conversation on the possible ecological drivers of extinction risk, the synergies that enhance ecological stress, and the taxonomy, ontogeny, and geography of change in and risk to marine, freshwater, and terrestrial mollusks. Join the forum to discuss the results of pertinent research on the effects of large-scale change on mollusks.

More information? Check the forum’s web site
www.mollusksinperil.org for more information and updates. See you on Sanibel in 2016!




Wednesday, February 17, 2016

Update on the status of the remaining Hawaiian land snail species Part 4: Punctidae and Endodontidae

                                 Norine W. Yeung and Kenneth A. Hayes

    For the fourth installment of our updates on the status of the Hawaiian land snail fauna
we discuss the Hawaiian families in the superfamily Punctoidea: Punctidae (Fig 1A) and
Endodontidae (Fig 1C, D).  Previously we reported on some of the smallest Hawaiian snails, the minute (<4 mm in shell height) Pupillidae, but these snails are not the smallest in the Hawaiian Islands.  Punctidae are commonly called “dot snails” because many are about 1 mm in shell
diameter, resembling little dots. They have a Holarctic distribution but with only one
currently recognized monotypic genus in Hawaii. But as we have seen, land snails
globally, and particularly in Hawaii, are ripe with cryptic species and the Hawaiian
Punctidae may harbor as many as nine undescribed species in the Bishop Museum
Malacology collection (Solem 1983). Their relationship to the majority of other
pulmonates remains uncertain, but in their phylogenetics analyses Wade et al (2006)
recovered a well supported clade containing the Charopidae, Otoconchidae and
Punctidae.  Based on our recent surveys and preliminary molecular analyses,
we have three native punctids and a nonnative species that had been previously mistaken to be a Hawaiian punctid, Paralaoma servilis (Fig 1B; Christensen et al. 2012). Most of these species
were recorded in high elevation forests but in low densities (<5 individuals at a given
site). Due to their size, these snails are often difficult to find and additional surveys and
assessments need to be made to update their taxonomy, distributions and conservation
status.

Family: Punctidae
Genus: Punctum
Number of recognized species: 1
Number of species found in recent surveys: 3 (2 undescribed)
Historical distribution: Oahu, Hawaii
Current distribution: Kauai, Oahu, Maui, Molokai, Hawaii
Conservation status: Threatened

    The Endodontidae, endemic and highly diverse in the Pacific islands, are restricted to
Polynesia, Lau Archipelago, and Palau (Solem 1976, 1990). In Hawaii, there are 33
recognized species with more than 200 undescribed taxa in the Bishop Museum
Malacology collection (Solem 1990). Endodontids have been thought of as the most
primitive 'higher' pulmonates (clade Sigmurethra) based on morphology (Solem 1983,
Tillier 1989), leading Bouchet & Rocroi (2005) to place them with the Punctidae in the
sigmurethran superfamily Punctoidea. However, they were not included in the molecular
analyses of Wade et al (2006), who found no support for this hypothesis (sensu
Bouchet & Rocroi 2005).

    Endodontids are highly threatened (Solem 1990, Sartori et al 2013, 2014) and in
Hawaii, all but three species are likely extinct. Solem (1990) reported that no live
Endodonta were collected on the main Hawaiian Islands since 1940 and the only
species left in this genus is on Nihoa along with a Cookeconcha species. He reported a
few Cookeconcha individuals alive in 1962 and M. Hadfield found only a couple in the
1980s, both in the Waianae Mountains of Oahu. Solem concluded that all low and midelevation
species, which accounts for the majority of the diversity, were extinct by 1960
and the remaining (< 5%) are confined in high elevation refugia. Meyer (2006) reported
the rediscovery of a remnant population of Coohkeconcha in the Waianae Mountains of
Oahu. Our recent surveys, have confirmed the persistence, although in small
populations, of Endodonta sp. on Nihoa and two Cookeconcha spp. (Waianae
Mountains, Oahu). Unfortunately, the Cookeconcha species reported from Nihoa in the
1980s was not found (Conant et al. 1983).

    Unlike the highly endangered Amastridae and Achatinellinae, there are currently no
captive rearing efforts for the remaining Hawaiian Endodontids. Unless there are
management plans in place to protect these remaining species, this family will likely be
extirpated from Hawaii in the next decade, and we will have lost another of these
evolutionary treasures. Along with them go the stories they tell about the history of
these islands and the fauna that have come to inhabit them.

Family: Endodontidae
Genus: Cookeconcha, Endodonta, Nesophila, Protoendodonta
Number of recognized species: 33
Number of species found in recent surveys: 3 (2 of which are undescribed)
Historical distribution: Kauai, Oahu, Maui, Lanai, Molokai, Hawaii, Northwestern
Hawaiian Islands
Current distribution: Oahu, Nihoa
Conservation status: Threatened

References

Bouchet, P. & Rocroi, J.P.  2005. Classification and nomenclator of gastropod families.
Malacologia 47: 1397.

Christensen, C.C., Yeung, N.W., & Hayes, K.A. 2012. First records of Paralaoma
servilis (Shuttleworth, 1852) (Gastropoda: Pulmonata: Punctidae) in the Hawaiian
Islands. Bishop Museum Occasional Papers 112: 37.

Conant, S., Christensen, C.C., Conant, P., Gagne, W., & Goff, M.L. 1983. The unique
terrestrial biota of the Northwestern Hawaiian Islands. Proc. Symp. Resource Invest.
Northwestern Hawaiian Islands, 2527 May 1983:7794.  Sea Grant Coli. Prog.
University of Hawaii, Honolulu.

Cowie, R.H., Evenhuis, N.L. & Christensen, C.C. 1995. Catalog of the native land and
freshwater molluscs of the Hawaiian Islands. Backhuys Publishers, Leiden. vi + 248
pp.

Meyer III, W.M. 2006. Records of rare grounddwelling
land snails on O ‘ahu. Bishop Museum Occasional Papers 88: 5758.

Solem, A. 1983. Endodontoid land snails from Pacific islands (Mollusca: Pulmonata:
Sigmurethra). Part II. Families Punctidae and Charopidae. Zoogeography. Field
Museum of Natural History, Chicago. [ix] + 336 p.

Solem, A. 1990. How many Hawaiian land snail species are left? and what we can do
for them. Bishop Museum Occasional Papers 30: 2740.

Tillier, S. 1989. Comparative morphology, phylogeny and classification of land slugs and
snails (Gastropoda: Pulmonata: Stylommatophora). Malacologia 30: 1303.

Sartori, A.F., Gargominy, O. & Fontaine, B. 2012. Anthropogenic extinction of Pacific
land snails: a case study of Rurutu, French Polynesia, with description of eight new
species of endodontids (Pulmonata). Zootaxa 3640: 343372.

Sartori, A.F., Gargominy, O. & Fontaine, B. 2014. Radiation and decline of endodontid
land snails in Makatea, French Polynesia. Zootaxa 3772.1: 168.

Wade, C.M., Mordan, P.B. & Naggs, F. 2006. Evolutionary relationships among the
Pulmonate land snails and slugs (Pulmonata: Stylommatophora). Biological Journal of
the Linnean Society 87: 593610.

Figure 1: Representatives of the Hawaiian Punctoidea A) native Punctum sp., B) nonnative
Paralaoma servilis C) Endodonta sp. D) Cookeconcha hystricella adult and
juvenile. Scale bar = 1 mm.




Monday, October 5, 2015

Update on the status of the remaining Hawaiian land snail species Part 3: Pupillidae and Succineidae



Norine W. Yeung and Kenneth A. Hayes


     In the third installment of our updates on the status of the Hawaiian land snail fauna we are covering the third and last of our Hawaiian Orthurethran families, the Pupillidae (Figure 1) and our only Elasmognathan representative, the Succineidae (Figure 2).

     The minute (<4 mm in shell height) Pupillidae belong in the Pupilloidea, and are thought to be Holarctic in origin, with a significant number of Pacific island land species.  The family level classifications differ among authors as do placement of genera with the Hawaiian species being treated as belonging to either in Pupillidae (Cowie et al. 1995) or Vertiginidae (Bouchet and Roucroi 2005).  There are 56 Hawaiian species in five genera (number of species in parentheses; Cowie et al. 1995): Lyropupa (22), Nesopupa (20), Pronesopupa (10), Pupoidopsis (1), Columella (3).  The sixth genus in Hawaii is represented by two non-native species, Gastrocopta servilis and G. pediculus (Cowie 1997).  Lyropupa is an endemic Hawaiian genus, Pronesopupa, Nesopupa and Pupoidopsis are distributed throughout the Pacific islands, and Columella has a global distribution.

     Twenty-five years ago Solem (1990) suggested that most of the Hawaiian “pupilloids” were extinct. However, our recent work has recovered multiple endemic taxa. Pronesopupa can be found in low elevation, non-native forests but the remaining Lyropupa and Nesopupa can only be found in upland native forests. Pupoidopsis hawaiiensis is likely extinct in Hawaii. Since 2010 we have recorded 23 species belonging to three Hawaiian genera (Nesopupa, Pronesopupa, and Columella). Ten additional species were recorded, but their native provenances are unknown as they are phylogenetically closer to North American Vertigo spp., a genus not recorded in Hawaii. Several of these unidentified species show conchological affinity to the endemic Hawaiian Lyropupa species, and it is possible that they are indeed undescribed native taxa. Based on preliminary molecular data, it is likely that all Hawaiian species should be referred to the Vertiginidae and not Pupillidae, but a full taxonomic revision of the group is needed.

     Most of the species recorded were from mid- and high-elevation forests and at most locations species appear abundant, with 10+ individuals easily found during our surveys. However for several species, only one or two individuals were found and additional surveys are needed to assess the conservation status of these species. Although we recovered numbers of species equivalent to nearly 58% of the described diversity, less than half of these have been referred to known described taxa, indicating that the historical diversity may have been much higher than initially estimated.

Family: Pupillidae/Vertiginidae
Subfamilies: Nesopupinae, Pupillinae, Vertigininae
Number of recognized species: 56
Number of species found in recent surveys: 23 (10 of unknown origins)
Historical distribution: Kauai, Oahu, Maui, Lanai, Molokai, Hawaii, Niihau, Kahoolawe
Current distribution: Kauai, Oahu, Maui, Molokai, Lanai, Hawaii
Conservation status: Threatened/Endangered

     Succineids have a global distribution primarily in damp areas close to fresh water (Pilsbry 1948, Barker 2001), but a few inhabit vegetated patches in dry areas (Baker 1965; Franzen 1985). In Hawaii, the 42 endemic species range from xeric coastal dunes to high elevation rainforests (Holland & Cowie 2007, 2009). The Succineidae originated in the Eocene in an unknown region (Tillier 1989), although their sister group, the Athoracophoridae, is thought to have originated within the Pacific Islands (Nordsieck 1986, Wade et al. 2006). Together the two families constitute the monophyletic Elasmognatha within the Stylommatophora, supported by molecular and morphological analyses (Dutra-Clarke et al 2001, Wade & Mordan 2001, Wade et al. 2006). The Succineidae are divided into two subfamilies (Succineinae and Catinellinae; Odhner 1950, Patterson 1971, Bouchet & Rocroi 2005), with both subfamilies represented in Hawaii (Cowie et al. 1995).

     The Hawaiian Succineidae have been reported to be one of the few families doing relatively well (Solem 1990), with many succineid species abundant in higher elevational forests. Recent surveys recovered twenty-six species from the six largest Hawaiian Islands. This represents more than half of the estimated diversity. However, similar to many other Hawaiian land snail families, fewer than half of these have been identified to recognized species, and a great deal of taxonomic revision is needed to fully understand the true levels of historical and current diversity.
     
     Initial phylogenetic analyses are consistent with previous reports of two major clades radiating in Hawaii (Holland and Cowie 2009), and a few taxa show a closer affinity to other Pacific islands than with Hawaiian endemics. All species recorded to date are single island endemics, with the exception of Succinea caduca. This pattern is inconsistent with previous records of many species spread across multiple islands, further suggesting that initial diversity estimates of Hawaiian Succineidae were too low.

Family: Succineidae
Subfamilies: Succineinae and Catinellinae
Number of recognized species: 42
Number of species found in recent surveys: 26
Historical distribution: Kauai, Oahu, Maui, Lanai, Molokai, Hawaii, Niihau, Kahoolawe
Current distribution: Kauai, Oahu, Maui, Molokai, Lanai, Hawaii
Conservation status: Threatened

References


Baker, R.E. 1965. Catinella arenaria Bouchard Chantereux at the Braunton Burrows National Reserve, Devon. Proceedings of the Malacological Society of London 36: 259-265.
Barker, G. M. 2001. Gastropods on land. In: G. M. Barker, ed., The Biology of Terrestrial Molluscs. CABI Publishing, Wallingford, U.K. Pp. 1-146.
Bouchet, P. & Rocroi, J.-P. 2005. Classification and nomenclator of gastropod families. Malacologia 47: 1-397.
Cowie, R. H.  1997.  Catalog and bibliography of the nonindigenous nonmarine snails and slugs of the Hawaiian Islands.  Bishop Museum Occasional Papers 50:1-66.
Cowie, R.H., Evenhuis, N.L. & Christensen, C.C. 1995. Catalog of the native land and freshwater molluscs of the Hawaiian Islands. Backhuys Publishers, Leiden. vi + 248 pp.
Dutra-Clarke, A.V.C., Williams, C., Dickstein, R., Kaufer, N. & Spolita, J.R. 2001. Inferences on the phylogenetic relationships of Succineidae (Mollusca, Pulmonata) based on the 18S rRNA gene. Malacologia 43: 223-236.
Franzen, D.S. 1985. Succinea vaginacontorta Lee (Gastropoda: Pulmonata: Succineidae). The Nautilus 99: 94-97.
Holland, B.S. & Cowie, R.H. 2007. A geographic mosaic of passive dispersal: population structure in the endemic Hawaiian amber snail Succinea caduca (Mighels, 1845). Molecular Ecology 16(12): 2422-2435 [cover illustration].
Holland, B.S. & Cowie, R.H. 2009. Land snail models in island biogeography: a tale of two snails. American Malacological Bulletin 27(1-2): 59-68.
Nordsieck, H. 1986. The system of the Stylommatophora (Gastropoda), with special regard to the systematic position of the Clausiliidae, II. Importance of the shell and distribution. Archiv für Molluskenkunde 117: 93–116.
Odhner, N. H. J.  1950.  Succineid studies: genera and species of subfamily Catinellinae.  Journal of Molluscan Studies 28(4-5):200-210.
Patterson, C. M.  1971.  Taxonomic studies of the land snails family Succineidae. Malacological Review 4:131-202.
Pilsbry, H. A. 1948.  Land Mollusca of North America (North of Mexico) vol. II, part 2.  Academy of Natural Sciences of Philadelphia, p. 521-1113.
Solem, A. 1990.  How many Hawaiian land snail species are left? and what we can do for them.  Bishop Museum Occasional Papers 30:27-40.
Tillier, S. 1989.  Comparative morphology, phylogeny and classification of land slugs and snails (Gastropoda: Pulmonata: Stylommatophora).  Malacologia 30:1-303.
Wade, C. M. & Mordan, P. B. 2001.  Evolution within the gastropod molluscs; using the ribosomal RNA gene-cluster as an indicator of phylogenetic relationships. Journal of Molluscan Studies 66(4):565-570.
Wade, C. M., Mordan, P. B. & Naggs, F.  2006.  Evolutionary relationships among the Pulmonate land snails and slugs (Pulmonata: Sylommatophora).  Biological Journal of the Linnean Society 87:593-610.


Figure 1: Representatives of the Hawaiian Pupillidae A) Vertigo sp., B) Pronesopupa sp.,C) Nesopupa sp., D) Vertigo sp., E) Pronesopupa sp. (scale bar = 1 mm)


Figure 2: Representatives of the Hawaiian Succineidae A) Catinella baldwini, B) Succinea lumbalis, C) Succinea spp. (scale bar = 1 cm)