Land Snail Species Research Articles

Three new species of Camaena Albers, 1850 (Gastropoda, Stylommatophora, Camaenidae) from Guizhou and Guangxi, China

AbstractThree new species of camaenid land snail, Camaena qiannanensis Chen, Dai, Wu & Ouyang sp. n., Camaena feichenyui Chen, Dai, Wu & Ouyang sp. n. and Camaena qinghuai Chen, Dai, Wu & Ouyang sp. n. are described from Guizhou and Guangxi of southern China based on shell and genital morphology, and molecular phylogeny. The phylogenetic result shows that the genus Camaena is not a monophyletic group, with Camaenella located within it. The discovery enhances the species diversity of Camaena in Southern China and fills the gap between distribution areas of known species.

Speciation in the desert: A new endemic Iberus land snail restricted to the southeastern Iberian Peninsula

Arid habitats constitute harsh environments for hydrophilic animals such as land snails. Still, several land snail species appear to inhabit arid environments and such species present an array of adaptations needed to minimise water loss in dry habitats. However, different species may have found different solutions for the same problem. Here, we describe Iberus xerophilus sp. nov., a new species of arid-dwelling land snail from southeastern Spain, on the basis of phylogenetic analyses. Moreover, we show a detailed morphological description as well as a characterization of its habitat. A comparison with the shell morphology of other aridity resistant Iberus land snails casts the question of how this snail can succeed in such harsh arid environments. Southeastern Spain constitutes a hotspot for Iberus arid-dwelling species, displaying a plethora of shell morphologies. The description of this new species might contribute to our understanding of the evolution and diversification of land snails specifically adapted to drought and arid conditions.

Preliminary Data on the Species Composition and Distribution of Land Snail (Mollusca: Gastropoda) in Son Doong Cave, Phongnha - Kebang National Park

Son Doong Cave it is the largest cave on the planet and also the most majestic cave in Vietnam. Son Doong Cave is divided into habitats: Dark cave (covered by the cave ceiling) and light cave (not covered by the cave ceiling), including doline 1 and doline 2.Surveying and collecting land snail samples in Son Doong cave was carried out in January 2023. For the first time, the list of terrestrial snail species in Son Doong Cave was published. This includes 30 species (11 phenotyps are just only identified to genus) belonging to 24 genera, 11 families, 3 orders, 3 subclasses; of which the presence of 5 species (Pincerna mouhoti, Leptopoma perlucidum, Scabrina patera, Chloritis khammouanensis, Amphidromus haematostoma) are newly recorded and added to the list of terrestrial gastropod fauna of Vietnam. In Son Doong cave, land snails are only distributed in the light part of the cave (Doline 1 and Doline 2), not in the dark part of the cave, which accounts for most of the cave area. Doline 2 has a higher species diversity (27 species belonging to 22 genera, 8 families, 2 orders) than Doline 1 (13 species belonging to 11 genera, 6 families, 3 orders). The diversity of land snail species in Son Doong cave is very unique and highly distinctive, but the species populations here is very small, requiring recommendations for tourists and the management board to protect vegetation to maintain and develop populations of this species.

NEW DISTRIBUTION RECORD OF Opisthostoma platycephalum (CAENOGASTROPODA: DIPLOMMATINIDAE) FROM PADANG BINDU KARST, SOUTH SUMATRA, INDONESIA

A fauna expedition has been conducted in Padang Bindu Karst, South Sumatra in 2021. Among the collected samples, a total of 111 specimens of Opisthostoma platycephalum (Caenogastropoda: Diplommatinidae) were collected from five sampling plots. This discovery is the first record of the land snail species in the southern of Sumatra island, as previous research only recognized its presence in Aceh, North Sumatra, and Peninsular Malaysia. This discovery contributes to the understanding of the biodiversity of South Sumatran land snails and highlights the importance of protecting limestone habitats.

Land snail assemblages along altitudinal gradients on Mount Semeru, the highest montane forest in Java, Indonesia

ABSTRACT We conducted research on land snail diversity on the highest volcanic mountain in Java, Mt Semeru. This research aimed to gain data on the land snail species diversity in the area as well as analyse environmental variables that affect the land snail assemblages along the altitudinal gradients. A total of 40 plots of 10 × 10 m2 were examined in the altitudinal gradient of 800–1,200, 1,201–1,600, 1,601–2,000 and 2,001–2,400 m asl using a timed search method. In total, 788 individuals of land snails were collected, belonging to 22 species from 14 families. Fifteen species were new records for the area. Five endemic species were recorded on Mt Semeru. A single introduced species, Bradybaena similaris was found abundantly on the mountain at an altitude of more than 2,000 m asl. Multiple linear regression analyses showed a unimodal response of species richness for altitude, temperature and precipitation sums on Mt Semeru. In addition to these environmental variables, species richness is influenced by land use type and soil pH. These findings suggest that species and ecosystem management at the altitude 2,001–2,400 m asl is necessary to conserve endemic land snail species, which were found most abundantly at this altitude.

Two new enid land snails from Jiuzhaigou County, Sichuan Province, China (Gastropoda: Stylommatophora: Enidae)

AbstractTwo new land snail species of the family Enidae, Serina xirong Chen, Dai, Wu & Ouyang sp. n. and Turanena jiuzhaigouensis Chen, Dai, Wu & Ouyang sp. n., are described from Jiuzhaigou County, Sichuan Province, China based on conchological morphology. Serina xirong can be distinguished from congeneric species by its ribbed teleoconch, and Turanena jiuzhaigouensis can be distinguished from congeneric species by its micro, conic, weakly keeled shell without color stripes before body whorl. This discovery further enhances our understanding of the enid species diversity in Sichuan Province.

Morphological and molecular data reveal the presence of exotic land snail species in Tierra del Fuego

In the present study, we report for the first time the presence of Vitrina pellucida and Arion silvaticus as invasive species in Isla Grande of Tierra del Fuego, Argentina. Additionally, our research confirmed the presence in the same region of Deroceras reticulatum a previously reported invasive species from continental Patagonia. Taxonomic identification was achieved through morphological and molecular analyses (ribosomal 5.8S-ITS2-28S region and 16S rRNAgene). The finding of V. pellucida constitutes the first record of Vitrinidae for South America. This species is already naturalized in southern Tierra del Fuego and invaded natural areas of the National Park but still with small populations. In the case of Arion silvaticus, we observed a comparable situation, as this species has not only been collected from urban areas but also from within the forests of the protected area. These exotic species of land snails are exclusively cold-adapted Pulmonates. Their feeding types and diets range from herbivores on fresh plant material to omnivorous, occasionally on dead animals. The native micro snail species, coexisting in the same habitats, due to their minimal dispersal capacity and probable dependence on particular microhabitats, are particularly vulnerable not only to anthropogenic disturbances but also to the impacts and activities of these exotic species. Given the tourist impact in the region, the introduction of V. pellucida and Arion silvaticus in Tierra del Fuego has most likely occurred through accidental transport in soil by tourists arriving on the island. Another possible pathway of introduction is plant transportation.

New camaenid genus and species from Zhejiang, East China (Eupulmonata, Helicoidea).

We report a new land snail species representing a new genus from the mountainous area of Zhejiang, China. The snail has a depressed shell with granules all over the surface. The soft part of the new taxon is characterized by the presence of a mantle lobe whose form is reviewed herein across a wide range of helicoid snails, the presence of a developed epiphallic papilla, and the absence of a penial sheath, a dart sac apparatus and a flagellum. As indicated by a molecular-based phylogeny (16S + ITS2), the new taxon is deeply nested in the eastern Asian camaenid genera and shows a close relationship with the camaenids distributed in Central China.

LAND SNAILS AND SLUGS (MOLLUSCA: GASTROPODA) IN THE INTERNATIONAL LOADING AND UNLOADING AREAS OF PANAMA

This study aims to identify the species of land snails and slugs that may invade Panama through the loading and unloading sites of national and international merchandise in Panama City and Colon, along with their probable places of origin. The investigation also considers the ecological, economic, and health impacts of these potential invasive species. Between September 2008 and September 2009, sampling was conducted at the main seaports and airports of Panama City and Colon, including their containers, warehouses, and surrounding natural habitats. The study utilized GPS for accurate location marking, and sampling occurred twice a week. Specimens were collected, with live material fixed in 70% alcohol, and slugs dissected for identification through sexual organs. Taxonomic identification involved conchological characteristics and expert consultation, with the data analyzed for species abundance correlation with precipitation and humidity. A total of 2379 individuals were collected, identifying seven species across nine genera and four taxonomic families, with the Subulinidae family being the most abundant. Notably, Praticolella griseola, an agricultural pest, and Hapiella w. f. decolorata were new records for Panama. The study found species richness and abundance correlated with rainfall but not relative humidity. The research highlighted the quarantine importance of several species due to their roles as pests and vectors of diseases like Angiostrongylus cantonensis and A. costarricensis. Panama hosts a moderate ecological diversity of gastropods, with certain species posing significant risks to agriculture, public health, and native ecosystems. The study underscores the necessity for ongoing surveillance and management of non-native mollusk introductions, particularly in a global trade hub like Panama. Identifying and understanding the distribution of invasive gastropods are crucial for developing effective control measures and mitigating their impact on the environment and human health.

Checklist of land snail species of Gua Rumbang, Sarawak, Malaysian Borneo (Mollusca, Gastropoda), with a description of a new species, Diplommatinarumbangensis sp. nov.

The current study presents an annotated checklist of the land snail species in the vicinity of the limestone hill of Gua (= cave) Rumbang, an outcrop located at the district of Padawan, Sarawak, Malaysian Borneo. The sampling was conducted at the surrounding areas and near the cave's entrance. A total of 62 species, involving 19 families and 38 genera, were recorded. Comparison with previous surveys made in the Bau limestone hills revealed similarities with respect to the species-rich families Diplommatinidae and Cyclophoridae, and the genera Kaliella and Diplommatina, highlighting the regional consistency of the land snail diversity of the Bau-Padawan-Serian cluster. Possibly because of its smaller size, Gua Rumbang is home to two endemic species, while there are eight endemic species in the Bau limestone karsts. This suggests a potential for a significant species diversity within the areas of the limestone ranges that remain to be explored. Nonetheless, the occurrence of endemic species in Gua Rumbang highlights the need to conserve certain areas within the Padawan limestone range since hitherto no protected areas have been proposed in this region. In this checklist, a new species for science is also described, namely, Diplommatinarumbangensissp. nov.

Repeated colonization of the Northern Limestone Alps from the Southern Limestone Alps by the rock‐dwelling snail species Cochlostoma henricae

AbstractHausdorf, B., Xu, J., BAMBERGER, S. (2024) Repeated colonization of the Northern Limestone Alps from the Southern Limestone Alps by the rock‐dwelling snail species Cochlostoma henricae—Zoologica Scripta, 00, 000–000. The evolution of biogeographic disjunctions in the Southern and Northern Limestone Alps has been studied only in a few taxa. Cochlostoma henricae (Strobel, 1851) is a land snail species restricted to limestone rocks showing such disjunctions. We studied the phylogeny and population structure of this species using genomic ddRAD data to better understand the differentiation of the species in the Southern Alps and the origin of the isolated occurrences in the Northern Limestone Alps. Phylogenetic and population‐genetic analyses of the ddRAD data revealed a subdivision of the C. henricae populations into a western cluster and an eastern cluster. These clusters were probably separated by glaciers that extended from the Piave Valley to the margin of the Alps. Such a longitudinal subdivision is a common pattern of several species in the Southern Limestone Alps. However, the boundaries between western and eastern population groups differ between taxa. Cochlostoma henricae colonized the Northern Limestone Alps at least twice. The population from Breitenwang in Tyrol originated from the western group, whereas the occurrences in the Salzkammergut are from the eastern group. These and similar disjunctions of several other land snails show that even species with limited dispersal abilities could cross the Alps repeatedly by passive long‐distance dispersal events. A subdivision of C. henricae into three subspecies, proposed based on shell characters, does not correspond to its population‐genetic structure. Instead, the eastern and western population groups represent distinct evolutionary units.

Revealing hidden diversity and community dynamics of land snails through DNA barcoding: implications for conservation and ecological studies

IntroductionLand snails play a crucial role in maintaining ecosystem sustainability within their habitats. Therefore, understanding the characteristics of their communities is vital for ecological studies and the development of effective conservation strategies. In this study, land snail communities inhabiting the Hyrcanian forest were identified and the variations in their community composition along elevational gradients were investigated.MethodsSnail samples were collected from three distinct elevations in three different forest locations within the Hyrcanian area of Iran. This study utilized DNA barcoding to identify land snail species. By employing statistical analyses such as ANOVA and PERMANOVA, significant differences in the features of snail communities across different elevations were examined. Concurrently, soil samples were collected from each site to assess soil physicochemical parameters about snail presence.ResultThrough this comprehensive analysis, a total of 10 OTUs, were further classified into seven families, and nine genera were identified. Five of these genera had never been reported in the study region before. We observed a decline in OTU richness with increasing elevation; however, the maximum abundance of snails was found at higher elevations. CCA demonstrated that Ca, Mg, and moisture saturation predominantly shape snail community composition.DiscussionThe unique climatic conditions and spatial distribution of precipitation from lowlands to highlands, as well as from west to east, make the Hyrcanian forests an ideal case study area for understanding the dynamics of land snail communities. In summary, this study provides new insights into the land snail communities thriving in the Hyrcanian forests. The findings from our research can contribute to the development of effective conservation management strategies for forest ecosystems. By understanding the factors influencing the distribution and composition of land snail communities, we can make informed decisions to protect and preserve land snails and the balance they maintain within their habitats.

Four new species of micro land snail in the genus Bensonella Pilsbry & Vanatta, 1900 (Stylommatophora: Hypselostomatidae) from Thailand

Four new species of micro land snail in the genus Bensonella Pilsbry & Vanatta, 1900 (Stylommatophora: Hypselostomatidae) from Thailand

Search for Snail Repellents: Antimollusc Activities from Stemona parviflora and Six Other Chinese Stemona Species.

Snails are important agricultural pests difficult to control, but data regarding molluscicidal assays are scant. Stemona alkaloids are typical secondary metabolites for the taxa and have been broadly investigated for their pharmacological and toxicological effects. This makes it possible for us to further develop the toxicities of these compounds to snails. In this work, we tested the antifeedant properties of leaves from seven Chinese Stemona species against the land snail species Bradybaena ravida in choice and non-choice feeding assays. The tested leaves Stemona parviflora exhibited the most deterrent effects, and a further phytochemical investigation of aerial parts led to the identification of 16 alkaloids. Among them, three novel alkaloids could be identified. The alkaloidal fraction and single alkaloids were further assayed against this snail species, and the results suggest a cocktail effect because the impact of the alkaloidal fraction was higher than the effects caused by single alkaloids. The study can promote the search process of natural antimollusc products from plants to control snails.

High‐Resolution Intrashell Oxygen Isotope Studies of Cathaica fasciola and Bradybaena ravida Land Snails and Their Environmental Implications

AbstractIntrashell oxygen isotope (δ18Os) analyses of terrestrial snails have been carried out over two decades. However, the intraspecies/interspecies differences are not yet well understood. Here, we conducted a high‐resolution intrashell δ18Os study on 43 shells from Cathaica fasciola and Bradybaena ravida, and 1449 δ18Os data were obtained. These large amounts of data demonstrate the reproducibility of intrashell δ18Os. Our results suggest that C. fasciola and B. ravida have similar growing seasons mainly from March to October in the studied region. The ecological habits of the two species could explain the distinctive variations in their δ18Os sequences. Therefore, our study may interpret the discrepancy between the studies of land snail species and the stable/clumped isotopes of their shells. Moreover, the calculated average growth rate is ∼290 μm/day (from 250 to 330 μm/day) for nonadult C. fasciola. Thus, the use of snail shells for reconstructing high‐resolution terrestrial climate changes is promising.

Slow and steady saves the race: molecular and morphological analysis of three new cryptic species of Iberus land snails from the Iberian Peninsula

The Iberian Peninsula constitutes a diversity hotspot with a high number of endemisms, where the land snail genus Iberus is likely the best example. Despite this, its species diversity is still debated as it holds several cryptic species. In the present paper, we use molecular evidence (mitochondrial DNA cytochrome oxidase subunit I) to clarify the position of I. ortizi and three new cryptic species that are described herein: I. giennensis, I. axarciensis and I. antikarianus spp. nov. For this, we sampled 281 sampling points to delimitate a comprehensive geographic mapping of these species. Moreover, we carried out a comprehensive morphometric analysis based on 3205 shells. Our findings show that, morphologically, the three described species overlap in the form of their shells, their morphologies being very similar to other close species with nearby distributions (I. ortizi, I. angustatus and I. marmoratus loxanus). Still, all these species are well-defined by genetic distances, but display allopatric distributions, suggesting that they evolved by allopatric speciation as a consequence of biogeographic isolation. Hence, our findings show insights into the evolution of land snails in southeastern Spain, with implications for their conservation, given that our exhaustive sampling shows that the three species described here have very limited distribution ranges, especially I. antikarianus sp. nov. Our study, moreover, implies an integrated approach to the study of the evolution of land snails, including the sampling of the complete geographic area occupied by the genus, genetic analysis to delimit the actual species range, as well as morphometric analyses to understand the phenotypic differentiation and adaptations of the three new species.

Salvation and documentation: additional (probable) type material of South American land-snail species (Gastropoda, Stylommatophora) in the Museum für Naturkunde Berlin

Type material of some South American species in the Museum für Naturkunde Berlin, belonging to different families is documented. It includes 16 species: Bulimus cuneus L. Pfeiffer, 1854, Bulimus proteus Broderip, 1832, Bulimus scalarioides L. Pfeiffer, 1867, Bulimus similaris J. Moricand, 1856, Andinia (Ehrmanniella) dedicata Weyrauch & Zilch, 1954, Helix hettneriana E. von Martens, 1897, Eurycampta hidalgonis Döring, 1877, Helix aequatoris L. Pfeiffer, 1860, Helix bituberculata L. Pfeiffer, 1853, Helix bourcieri L. Pfeiffer, 1853, Helix neogranadensis L. Pfeiffer, 1845, Cyclostoma (Cyclophorus) bourcieri L. Pfeiffer, 1854, and Helix platygyra Albers, 1857. The concept of the “salvation” of type material is explained.

A description of a new species of the genus Brachydistomum (Trematode, Dicrocoeliidae) from the Eurasian Tree Sparrow Passer montanus (Linnaeus) (Passeriformes) in Japan, with a report on the first intermediate host.

The trematode Brachydistomum suzume n. sp. (Dicrocoeliidae) was detected in the Eurasian Tree Sparrow Passer montanus, and described as a new species in Japan. This new species can be distinguished from the other members of the genus on the basis of morphological characters of suckers and reproductive organs. A partial sequence of adult mitochondrial cytochrome c oxidase subunit 1 (COI) was used as a DNA barcode, and dicrocoeliid sporocysts and cercariae detected from four camaenid land snail species, Bradybaena pellucida, Brad. similaris, Acusta sieboldiana and Euhadra brandtii, were molecularly identified as the new species. Phylogenetic trees of nuclear 28S ribosomal DNA and COI also showed the new species to be distinct from the other trematode species, including Brachydistomum spp.

The land snail fauna of Batu Kudik, isolated limestone outcrop near Simunjan, Sarawak, Malaysian Borneo (Mollusca, Gastropoda).

The present study provides a checklist of land snails collected from Batu Kudik, a small and isolated limestone outcrop in Simunjan, Sarawak. A total of 24 species of land snails, representing 18 genera and 14 families were recorded, including one newly-described subspecies. The most species-rich of the families in Batu Kudik are Diplommatinidae (17%) and Chronidae (17%) with four recorded species from each of the families. Based on our analysis, Plectostomawallaceikudikense subsp. nov., Opisthostomajavanica and Georissapyrrhoderma were identified as the most abundant land snails at this isolated outcrop, whereas Diplommatinaonyx and Everettiaminuta were recorded as the least abundant. All of the land snails at Batu Kudik were exclusively found sheltered between limestone boulders, underscoring the critical role of this outcrop as their refuge for survival. Consequently, conserving this biodiversity-rich limestone area becomes paramount to prevent the local extinction of these land snail species and possibly other organisms that depend on the unique attributes of the limestone for their survival. We also provide detailed descriptions of Plectostomawallaceikudikense, a new subspecies of the genus Plectostoma which is endemic to Batu Kudik. A description of a new subspecies Plectostomawallaceikudikense subsp. nov.

The terrestrial gastropods in three Dodecanese islands, Rhodes, Symi, Chalki (Aegean Sea, Greece)

Rhodes, Symi and Chalki are three islands with different characteristics in the southeastern part of the Aegean Sea. In this work, we present their complete land snail fauna based on recent survey, samples from the collections of the Natural History Museum of Crete and a thorough bibliographic review. We report 67 land snail species from Rhodes, 34 species from Symi, and 32 from Chalki, with 4, 20 and 9 new records for each island, respectively. Also, one species has been added to the malacofauna of Greece, while many names, which were mentioned mainly in the 19th century, have been clarified, synonymised or abolished from the lists of the islands. Our results once again demonstrate the importance of the reproductive system as a tool for reliable assessment of the taxonomy of Aegean land snails, and that sampling during the rainy season should be the preferred methodological approach for collecting land snails in the Greek islands.