Tag: snails

Out of the dark: historical cave snail collection rediscovered in the attic

Stored in the attic for decades, the shell collection of Dominik Bilimek at BOKU University hides a plethora of untold narratives.

Guest blog post by Petra Lukeneder and Adrienne Jochum

During the past years, interest in the processing and preservation of historical, scientific collections has increased significantly. Fascinating and obscure treasures are stored along with their individual stories while splendid and exciting specimens eke out an existence in boxes and cellars. The scientific curation of the Dominik Bilimek (1813-1884) Collection at BOKU University (Vienna, Austria) is one such example. Stored in the attic for many decades, later stashed in the basement, surviving two floods, a plethora of untold narratives unfolded as the specimens were unpacked. For example, the story of the young, aspiring, Slovenian collector and researcher, Heinrich Hauffen (1836-1866), with his special interests in speleology and the fauna inhabiting the subterranean realm come to light.

A grainy black-and-white photograph of a bearded man. — The only known photograph of collector and naturalist Heinrich Hauffen (1836-1866) (Digital Library of Slovenia; reference number 5S74D58Z).

At first, it was just a label type in the collection that differed from the others. It was a multidisciplinary process to assign it to Hauffen. At that time, only few scientists were concerned with the genus Carychium, including Georg von Frauenfeld (1807-1873), Heinrich Freyer (1802-1866), and Meinrad Thaurer von Gallenstein (1811-1872), all of whom were names that were closely linked to Bilimek and his collection. Fortunately, Hauffen’s handwriting could be identified by using original manuscripts from the Archive of the National Museum of Slovenia.

In our work published in Subterranean Biology, we present our results on the rediscovery of historical material of Heinrich Hauffen, which turned out to be original material, that he used to describe the cave snail taxa Carychium reticulatum and Carychium reticulatum bidentatum. Today, the eastern Alpine and the Dinaric subterranean members of the genus Carychium are assigned to their own genus, Zospeum, based on their troglobiontic characteristics such as lack of eyes, colourless bodies, genetic data, and their totally different shell morphology.

A photograph of a tiny white snail attached to a rocky surface, with a yellow arrow to indicate the location of the snail — Live animal, indicated by the yellow arrow, of the genus *Zospeum* from Krska jama cave in Slovenia. The snail’s shell appears almost to be translucent.

This interdisciplinary work not only includes historical aspects, but also a collaboration with the Natural History Museum Vienna and the Department of Evolutionary Biology (University of Vienna) in conjunction with the taxonomic expertise from the Natural History Museum Bern (Bern, Switzerland), the Senckenberg Research Institute and Natural History Museum (Frankfurt am Main, Germany) and from the Zoologische Staatssammlung München (Münich, Germany). By using light microscopy, X-ray Micro-CT data and SEM in sync with Hauffen’s original figures and handwritten documents, the morphological analysis of C. reticulatum illustrates the degree of phenotypic variation on the shells of individuals from two different cave populations of the species Zospeum spelaeum. The species Carychium bidentatum is considered a junior synonym of Zospeum costatum.

Photographs of people taking samples from caves. — Cave snail collection during field work in Slovenia and Spain.

The genus Zospeum constitutes a radiation of minute, glassy troglobitic snails (Ellobioidea) endemic to the Eastern Alps and the Dinaric Alps, extending as far west as Lake Garda in Italy and as far south as Montenegro. So far, 38 species of Zospeum have been described. Morphologically, the most informative diagnostic characters are apertural form and the degree of coiling and the shape of the columella (inner spindle) as well as the presence and configuration of the lamella in relation to it. In the Pre-Micro-CT era, one had to poke windows into the shells to view these signatory structures. Valuable material could become damaged, and many taxonomists shied from risky mishaps to assess the tiny shells (< 1.5 mm). This present work demonstrates the efficacy of fine-resolution imagery to assess valuable historic material.

A photograph of a woman walking past drawers of specimens — Archive of the Institute of Applied Geology (BOKU University), where the Bilimek Collection including Hauffen’s material, is being stored and processed. Photo by Radek Polách, Muzea Novojičínska.

Hauffen died at the age of 30 as part of the Austrian volunteer corps in Mexico – with the prospect of a permanent position at the Mexican National Museum. According to current knowledge, this is the reason why the Hauffen collection was passed on to Bilimek, who returned to Europe in 1867. There are still abundant specimens, often from localities that cannot longer be sampled nowadays, from Hauffen within the Bilimek collection. In the future, this part can hopefully be separated and scientifically processed as well.

Research article:

Lukeneder P, Ottner F, Harzhauser M, Winkler V, Metscher B, Ruthensteiner B, Jochum A (2024) Lost & Found – Rediscovery of H. Hauffen’s Carychium material in the Dominik Bilimek Collection, BOKU University, including a contemporary assessment within the genus Zospeum (Gastropoda, Ellobioidea, Carychiinae). Subterranean Biology 49: 97-116. https://doi.org/10.3897/subtbiol.49.130692

Miniature Snail in a Rock Sandwich

First fossil record of thorn snails in the southern United States

Researchers from the USA and Switzerland, including Senckenberg scientist and first author Dr. Adrienne Jochum, have described the first fossil Carychium land snails from Florida. The rock layer containing the snail fossils, which are only a few millimeters in size, was accidentally uncovered during construction work and dates from the Pleistocene period between 2.58 million and 11,700 years ago. In their study, published in the open-access journal ZooKeys, the scientists also describe a previously unknown carychiid fossil species.

Light microscopic images of Carychium nashuaense.

The tiny snails of the genus Carychium with a maximum height of 2.5 millimeters and a width of 1.5 millimeters are known mostly east of the Mississippi River in the USA and from eastern Canada, Mexico and Jamaica as well as in sheltered humid habitats in Central America to Panama. “However, unlike the extant species, fossilized thorn snails are rarely found east of the Mississippi River. In our recent field work we have now provided the first fossil record of the genus in the southeastern United States, as well as the first fossil record ever for the species Carychium floridanum,” explains Dr. Adrienne Jochum of the Senckenberg Research Institute and Natural History Museum in Frankfurt and the Natural History Museum in Bern.

During the construction of a track bed for the Brightline railroad, which will connect Port Canaveral with Orlando International Airport, civil engineers accidentally came across a one-meter-thick layer of fossilized non-marine gastropods between two marine shell beds. “This ‘rock sandwich’ was formed during the Pleistocene, a geologic era characterized by repeated glaciations, climate changes, and fluctuations in water level that greatly influenced and shaped the region around present-day Florida. The shell layer is sandwiched between rock layers from the Lower Pleistocene, 2.58 to 0.77 million years ago, and the Upper Pleistocene, 140,000 to 120,000 years ago, and contains 14 freshwater and 28 terrestrial snail species.”

Later stage of excavation showing middle stratum of freshwater marl (c. 1 m thick) wedged between two layers of marine shell layers (each c. 3 m thick).

Among them is the snail Carychium floridanum, whose current representatives still live in humid, forested, and undisturbed habitats in central and northern Florida. The researchers also described a new species, Carychium nashuaense, which is less than 1.6 millimeters long and was previously unknown to science.

“To dislodge the fossil miniature snails from the rock layers, we first washed them through a graduated series of sieves. Next, 32 Carychium shells were culled under a microscope from a mixture of other mollusks and rock debris. A high-resolution X-ray tomograph helped us examine the spindle structure inside the fragile fossil shells and compare them with 3D reconstructions of the inner shell of still-living thorn snail species from the southeastern U.S., Mexico, Central America, and Jamaica,” explains Jochum.

While the design of the inner shell structure of Carychium floridanum has changed little from the Pleistocene to the present, the shell structure of Carychium nashuaense suggests a relationship with Central American Carychium relatives. “We suspect that the spread of the snails occurred via birds, mammals, and reptiles, who transported the small snails in their guts, fur, or feathers to the wetlands from which the alluvial sediments in the rock layer we studied originated. The subsequent mixing with other members of the genus led to the emergence of new species,” adds Jochum in conclusion.

***

Publication:

Jochum A, Bochud E, Haberthür D, Lee HG, Hlushchuk R, Portell RW (2023) Fossil Carychiidae (Eupulmonata, Ellobioidea) from the Lower Pleistocene Nashua Formation of Florida, with the description of a new species. ZooKeys 1167: 89-107.
https://doi.org/10.3897/zookeys.1167.102840

Press release originally published by Senckenberg. Republished with permission.

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Alien land snail species are increasing exponentially

A new study compiles an overview of the exponential increase and dynamic spread of land snail species introduced to Europe and the Mediterranean.

Invasive land snail species can displace native species and harm human health. A recent study by the Leibniz Institute for Biodiversity Change Analysis (LIB) compiles an overview of the exponential increase and dynamic spread of land snail species introduced to Europe and the Mediterranean from other continents.

*Laevicaulis alte*, an invasive species from tropical Africa that was introduced into Egypt in 2018. © Reham F. Ali

To date, there is a lack of information for the spread of alien species, especially invertebrates such as snails. “Despite efforts to compile lists of alien species, there is not even a well-documented inventory of alien invertebrate species for Europe,” emphasizes Prof. Dr. Bernhard Hausdorf, section leader Mollusca at LIB. His study, just published in the journal NeoBiota, provides a basis for decisions on further measures to control or eradicate introduced populations.

Alien land snail species in the Western Palaearctic Region: Zonitoides arboreus, Hawaiia minuscula, Guppya gundlachii, Polygyra cereolus

Land snails play a supporting role in ecosystems. They decompose decaying plants and thus play an important role in nutrient cycling and soil formation. However, more and more species are being spread beyond their native range, usually by humans, sometimes intentionally, but often unintentionally by goods or travellers.

The study examines 22 land snail species introduced to Europe and the Mediterranean from other continents. Most of them are small, live on decaying plant parts and apparently cause few problems. In contrast, carnivorous species can threaten native species; and species that feed on living plants can cause damage to agriculture. Some even serve as hosts and vectors of parasites that can cause brain encephalitis, for example, and thus can indirectly harm human health.

Alien land snail species in the Western Palaearctic Region: *Paralaoma servilis* and *Helicodiscus parallelus*.

Harmful species include the Laevicaulis species recently introduced to the Mediterranean from tropical Africa and the African giant snail Lissachatina fulica. They can cause economic damage on irrigated farmland or in greenhouses by destroying or contaminating crops, making them unsaleable.

Hausdorf’s study compiles records of land snail species introduced to the Western Palearctic region, Europe and the Mediterranean, from other regions after 1492 and established in the wild. In doing so, he observes that the number of alien species has increased steadily since the 19th century, even exponentially from the 1970s onward, and that the introduced species have become more widespread.

Within Europe, alien species generally spread from south to north and from west to east. Thirteen of the 22 species studied were from North America, three from sub-Saharan Africa, two from the Australian region, three probably from the Oriental region, and one from South America.

Even if trade relations and the spread of species can be correlated, Hausdorf believes that the prevailing climate is primarily decisive: “The spread of many of the introduced species, especially the tropical species dispersing in Mediterranean, is probably favored by climate change.”

Bernhard Hausdorf, “Distribution patterns of established alien land snail species in the Western Palaearctic Region”, NeoBiota, Pensoft
https://doi.org/10.3897/neobiota.81.96360

Press release originally published by Leibniz Institute for the Analysis of Biodiversity Change. Republished with permission.

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Swimmer’s Itch: what causes this neglected snail-borne disease?

A new study suggests that a cercarial dermatitis outbreak in South Thailand was caused by the blood fluke Schistosoma indicum.

Cercarial dermatitis, also known as swimmer’s itch or clam-digger’s itch, is caused by the larvae of blood flukes that are parasites of birds or mammals. When these larvae, called cercariae, penetrate human skin, they trigger an allergic reaction within 10-15 hours that takes about a week to heal. Unable to mature into adults, the larvae then die on the skin. The gravity of an outbreak depends on how humans and birds or mammals come in contract with the aquatic environment, but people engaged in water activities, such as farmers, fishermen, and agricultural workers, are most likely to be affected.

Cercarial dermatitis cases from Chana district, October 2020

Between August and October 2020, a cercarial dermatitis outbreak with 359 confirmed cases occurred in Chana district, Songkhla Province, South Thailand. It mostly affected rice farmers from the area, who were busy with cultivation during the rainy season. Following a short investigation, three cases of patients were confirmed to be cercarial infections by skin biopsy (Bureau of Epidemiology, Department of Disease Control, Ministry of Public Health, Thailand).

“The study of intermediate host and definitive host in the outbreak area are important for the control program of snail-borne disease,” the researchers argue in their research paper, which was published in the open-access scientific journal Evolutionary Systematics.

Having studied six snail species from the area, they found out that two were infected, each with three different species of flatworms. The cercarial dermatitis outbreak was due to ruminant parasites, such as the blood fluke Schistosoma indicum, which often uses domestic animals as its host.

Collected snails from five locations of cercarial dermatitis outbreak area. a. *Filopaludina s. peninsularis* b. *Filopaludina s. polygramma* c. *Indoplanorbis exustus* d. *Filopaludina m. cambodjensis* e. *Bithynia s. siamensis* f. *Pomacea canaliculat*a (Scale bar: 1 cm).

“Ruminant-infecting trematodes, namely, S. indicum and S. spindale, cause a hepato-intestinal schistosomiasis resulting in reduced milk yield,” the authors explain. “This occurrence of S. indicum and S. spindale implies the spread of cattle blood fluke cercariae in aquatic environments.”

“Additionally, these species of the S. indicum group primarily cause cercarial dermatitis in humans, which has become an important public health issue for people living in endemic regions.”

“In South India and Southeast Asia, where S. indicum and S. spindale have been reported to be widespread, they caused major pathology and mortality to livestock, leading to welfare and socio-economic issues, predominantly among poor subsistence farmers and their families.”

Image of *Schistosoma indicum* Montgomery, 1906 (Syn. *S. nasalis* Rao, 1933) a. Head organ of cercaria stained with 0.5% neutral red (DIC microscopy) b. Body part of cercaria stained with 0.5% neutral red (DIC microscopy) c. Image of unstained cercaria (DIC microscopy) d. Images of cercaria stained with 0.5% neutral red (DIC microscopy) e. Drawing of cercaria structure f. Images of sporocyst stained with 0.5% neutral red (light microscopy) Abbreviations: c: cercaria, eb: excretory bladder, ep: esophagus, fu: furca, h: head organ, i: intestine, pg: penetration gland, sp: sporocyst, ta: tail, vs: ventral sucker.. (Scale bars: 100 μm).

Some of the other worm species they found parasitized the intestines of fish, mammals, or birds, while others caused anemia and even death in ruminant animals.

“The results of this study will provide insights into the parasite species that cause cercarial dermatitis and may improve our understanding of public health problems in the outbreak and agricultural vicinity areas,” the authors of the study say. “In addition, the sequence data generated here are the first S. indicum DNA sequences from Thailand, which will be useful for further genetic study of the other blood flukes in this region.”

Research article:

Krailas D, Namchote S, Komsuwan J, Wongpim T, Apiraksena K, Glaubrecht M, Sonthiporn P, Sansawang C, Suwanrit S (2022) Cercarial dermatitis outbreak caused by ruminant parasite with intermediate snail host: schistosome in Chana, South Thailand. Evolutionary Systematics 6(2): 151-173. https://doi.org/10.3897/evolsyst.6.87670

Images by Professor Dr. Duangduen Krailas.

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Agents of food-borne zoonoses confirmed to parasitise newly-recorded in Thailand snails

Parasitic flatworms known as agents of food-borne zoonoses were confirmed to use several species of thiarid snails, commonly found in freshwater and brackish environments in southeast Asia, as their first intermediate host. These parasites can cause severe ocular infections in humans who consume raw or improperly cooked fish that have fed on infected snails. The study, conducted in South Thailand by Thai and German researchers and led by Kitja Apiraksena, Silpakorn University, is published in the peer-reviewed open-access journal Zoosystematics and Evolution.

“Trematode infections are major public health problems affecting humans in southeast Asia. Trematode infections depend not only on the habit of people, but also on the presence of first and second intermediate host species, resulting in the endemic spread of parasites, such as intestinal and liver flukes in Thailand”.
explain the scientists.

The snails of concern belong to the genus Stenomelania, have elongated and pointed shells and can be found near and in the brackish water environment of estuaries in the Oriental Region, from India to the Western Pacific islands. Worryingly enough, science does not know much else about these snails to date. Further, these species are hard to distinguish from related trumpet snails, because of the similarities in their shell morphology.

In order to provide some basic knowledge about the parasitic worms in Thailand and neighbouring countries, the research team collected a total of 1,551 Stenomelania snails, identified as four species, from streams and rivers near the coastline of the south of Thailand in Krabi, Trang and Satun Provinces. Of them, ten were infected with trematodes. The parasites were found at seven of the studied localities and belonged to three different species. In Krabi Province, the researchers observed all three species.

Speculating on their presence, the scientists suspect that it could be related to the circulation of sea currents, as the flow of water along the Andaman coast is affected by the monsoon season.

In conclusion, the researchers note that it is a matter of public health that further research looks into the biodiversity and biology of these snails, in order to improve our knowledge about the susceptibility of Stenomelania snails to food-borne zoonotic.

“This finding indicated that the resulting parasitic diseases are still largely neglected in tropical medicine, so further studies should be performed on the prevalence of various trematode-borne diseases in locations with snail occurrences in Thailand,”
they say.

Research article:

Apiraksena K, Namchote S, Komsuwan J, Dechraksa W, Tharapoom K, Veeravechsukij N, Glaubrecht M, Krailas D (2020) Survey of Stenomelania Fisher, 1885 (Cerithioidea, Thiaridae): The potential of trematode infections in a newly-recorded snail genus at the coast of Andaman Sea, South Thailand. Zoosystematics and Evolution 96(2): 807-819. https://doi.org/10.3897/zse.96.59448

Tiny cave snail with muffin-top waistline rolls out of the dark in Laos

Tham Houey Yè cave (Vientiane Province, Laos), inhabited by the newly discovered “muffin-topped” snail species Laoennea renouardi.
Photo by Jean-Francois Fabriol.

A new species of tiny cave snail that glistens in the light and has a muffin-top-like bulge, was discovered by Marina Ferrand of the French Club Etude et Exploration des Gouffres et Carrières (EEGC), during the Phouhin Namno caving expedition in Tham Houey Yè cave in Laos in March 2019. The new species, Laoennea renouardi, is 1.80 mm tall and is named after the French caver, Louis Renouard, who explored and mapped the only two caves in Laos known to harbor this group of tiny snails. Only two species of Laoennea snail are known so far, L. carychioides and now, L. renouardi.

Caver and scientist, Dr. Adrienne Jochum, affiliated with the Natural History Museum Bern and University of Bern (Switzerland), as well as the Senckenberg Research Institute and Natural History Museum (Frankfurt, Germany) described the new species and its cave habitat together with co-authors: Estée Bochud, Natural History Museum Bern; Quentin Wackenheim, Laboratoire de Géographie Physique (Meudon, France) and Laboratoire Trajectoires (Nanterre, France); Marina Ferrand, EEGC; and Dr. Adrien Favre, Senckenberg Research Institute and Natural History Museum, in the open-access, peer-reviewed journal Subterranean Biology.

The new transparent “muffin-topped” snail, *Laoennea renouardi.*
Photo by Estée Bochud.

“The discovery and description of biodiversity before it disappears is a major priority for biologists worldwide. The caves in Laos are still largely underexplored and the snails known from them remain few in number,”
points out Dr. Jochum.

The fact that two species of tiny cave snails of the same group were found in two caves located in two independent karstic networks 3.4 km apart, caused the authors to question evolutionary processes in these underground hotspots of biodiversity. The authors hypothesise that the two caves might have been connected during the Quaternary, around 100–200 thousand years ago. In time, the river Yè might have formed a barrier, thus disconnecting the cave systems and separating the populations. As a result, the snails evolved into two different species.

A new species of tiny cave snail that glistens in the light and has a muffin-top-like bulge, was discovered by Marina Ferrand of the French Club Etude et Exploration des Gouffres et Carrie?res (EEGC), during the Phouhin Namno caving expedition in Tham Houey Yè cave in Laos in March 2019. The new species, Laoennea renouardi, is 1.80 mm tall and is named after the French caver, Louis Renouard, who explored and mapped the only two caves in Laos known to harbor this group of tiny snails. Only two species of Laoennea snail are known so far, L. carychioides and now, L. renouardi.

Caver and scientist, Dr. Adrienne Jochum, affiliated with the Natural History Museum BernUniversity of Bern (Switzerland), as well as the Senckenberg Research Institute and Natural History Museum (Frankfurt, Germany) described the new species and its cave habitat together with co-authors: Estée Bochud, Natural History Museum Bern; Quentin Wackenheim, Laboratoire de Géographie Physique (Meudon, France) and Laboratoire Trajectoires (Nanterre, France); Marina Ferrand, EEGC; and Dr. Adrien Favre, Senckenberg Research Institute and Natural History Museum, in the open-access, peer-reviewed journal Subterranean Biology.

Map of the two caves on opposite sides of the River Yè, Vientiane Province, Laos.
Image by Louis Renouard.

The fact that two species of tiny cave snails of the same group were found in two caves located in two independent karstic networks 3.4 km apart, caused the authors to question evolutionary processes in these underground hotspots of biodiversity. The authors hypothesise that the two caves might have been connected during the Quaternary, around 100-200 thousand years ago. In time, the river Yè might have formed a barrier, thus disconnecting the cave systems and separating the populations. As a result, the snails evolved into two different species.

***

Original Source:

Jochum A, Bochud E, Favre A, Ferrand M, Wackenheim Q (2020) A new species of Laoennea microsnail (Stylommatophora, Diapheridae) from a cave in Laos. Subterranean Biology 36: 1-9.
https://doi.org/10.3897/subtbiol.36.58977

Tiny thorn snail discovered in Panama’s backyard

*Close-up view of live individuals of the new species crawling on a leaf.*

Discoveries of biodiversity at the Lilliputian scale are more tedious than it is for larger animals like elephants, for example. Furthermore, an analysis producing a DNA barcode – a taxonomic method using a short snippet of an organism’s DNA – is not enough to adequately identify it to the species level.

In the case of tiny thorn snails – appearing as minute white flecks grazing in moist, decomposing leaf litter – it is the shell that provides additional and reliable information needed to verify or question molecular assessment of these otherwise, nondescript critters.

*Broadleaf forest litter with white arrows indicating the newly described species on the leaves.*

However, at 2 mm, thorn snails are too small and fragile to handle and the few, if any, tangible details on the outside of the shells can only be seen using a high-powered microscope and computed tomographic (CT) images.

This is exactly how the interdisciplinary team of Dr Adrienne Jochum, Naturhistorisches Museum der Burgergemeinde Bern (NMBE) and University of Bern, Dr. Bernhard Ruthensteiner, Zoologische Staatssammlung Muenchen, Germany, Dr. Marian Kampschulte, University Hospital of Giessen and Marburg, Gunhild Martels, Justus-Liebig University Giessen, Jeannette Kneubühler, NMBE and University of Bern, and Dr. Adrien Favre, Senckenberg Research Institute and Natural History Museum Frankfurt, managed to clarify the identity of a new Panamanian species. Their study is published in the open-access journal ZooKeys.

Even though the molecular analysis flagged what it was later to be named as the new to science species, Carychium panamaense, the examination left no shell for the description of the new snail to be completed, let alone to serve as tangible, voucher material in a museum collection available to future researchers. The mini forest compost-grazer had to wait for another five years and Dr. A. Favre, who collected fresh material while traveling in Panama.

The new snail is currently the second member of the family Carychiidae to be discovered in Panama. The first Panamanian, and southern-most member of its kind in the Western Hemisphere, is C. zarzaae, which was also described by Dr. A. Jochum and her team along with two sister species from North and Central America. The study was published in ZooKeys last year.

Much like X-rays showing the degree of damage in a broken bone, CT images visualise the degree of sinuosity of the potato chip-like wedge (lamella) along the spindle-like mast (columella) inside the thorn snail’s shell. These structures provide stability and surface area on which the snail exerts muscular traction while manoeuvring the unwieldy and pointed, signature thorn-like shell into tight nooks and crannies. The alignment and degree of waviness of the lamella on the columella is also used by malacologists (mollusc specialists) to differentiate the species.

*These are computed tomographic (CT) images of the new thorn snail species.*

Normally, a study of a thorn snail’s shell would require drilling out minute ‘windows’ in the shell by using a fine needle under a high microscope magnification.

“This miserable method requires much patience and dexterity and all too often, the shell springs open into oblivion or disintegrates into dust under pressure,” explains Dr. A. Jochum. “By exposing the delicate lamella using non-manipulative CT imaging, valuable shell material is conserved and unknown diversity in thorn snails becomes widely accessible for further study and subsequent conservation measures.”

The authors are hopeful that C. panamaense and C. zarzaae, which both inhabit the La Amistad International Park, Chiriquí, will remain a conservation priority along with other animalian treasures including the Resplendent Quetzal, Three-Wattled Bellbird and the Crested Eagles.

The park is considered the 1st bi-national biosphere reserve, as it occupies land in both Costa Rica and Panama, and constitutes a UNESCO World Heritage Site since 1990.

###

Original Source:

Jochum A, Ruthensteiner B, Kampschulte M, Martels G, Kneubühler J, Favre A (2018) Fulfilling the taxonomic consequence after DNA Barcoding: Carychium panamaense sp. n. (Eupulmonata, Ellobioidea, Carychiidae) from Panama is described using computed tomographic (CT) imaging. ZooKeys 795: 1-12. https://doi.org/10.3897/zookeys.795.29339

New ‘scaly’ snails species group following striking discoveries from Malaysian Borneo

Six new species of unique land snails whose shells are covered with what look like scales have been described from the biodiversity hotspot of Malaysian Borneo by scientists Mohd Zacaery Khalik, Universiti Malaysia Sarawak, Kasper Hendriks, University of Groningen, Jaap Vermeulen, JK Art & Science, and Prof Menno Schilthuizen, Naturalis Biodiversity Center. Their paper is published in the open access journal ZooKeys.

Thanks to their conspicuous structures, the mollusks have been added to a brand new species group of land snails to be commonly known as the ‘scaly’ snails, so that they can be set apart from the rest in the genus Georissa. Why it is that only some of the species in the genus sport the unique ‘scales’, remains unknown.

Fascinated with the minute ‘scaly’ snail fauna of Borneo, the researchers carried out fieldwork between 2015 and 2017 to find out how these curious shells evolved. In addition, they also examined material deposited in museum and private snail collections.

Apart from DNA data, which is nowadays commonly used in species identification, the team turned to yet-to-become-popular modern tools such as 3D modelling, conducted through X-ray scanning. By doing so, the researchers managed to look at both the inner and outer surfaces of the shells of the tiny specimens from every angle and position, and examine them in great detail.

The researchers note that to identify the ‘scaly’ snails to species level, one needs a combination of both DNA and morphological data:

“Objective species delimitation based solely on molecular data will not be successful for the ‘scaly’ snails in Georissa, at least if one wishes for the taxonomy to reflect morphology as well.”

The six new species are all named after the localities they have been originally collected from, in order to create awareness for species and habitat conservation.

###

Watch rotation and cross-section of the 3D models of the studied species here.

Original source:

Khalik MZ, Hendriks K, Vermeulen JJ, Schilthuizen M (2018) A molecular and conchological dissection of the “scaly” Georissa of Malaysian Borneo (Gastropoda, Neritimorpha, Hydrocenidae). ZooKeys 773: 1-55. https://doi.org/10.3897/zookeys.773.24878

Threatened Alabama snail renamed after a case of mistaken identity

Contrary to what scientists have known for over 100 years, the Painted Rocksnail turns out to have never existed outside the Coosa River system

Alabama has some of the highest diversity of freshwater snails in the world, but many snails are at high risk of extinction.

An essential part of determining extinction risk is knowing the range of a given species and determining how much its range has contracted owing to anthropogenic impacts, but mistaken identity or misidentification can complicate conservation efforts.

The Painted Rocksnail, a small snail from the Coosa River system, has been mistakenly identified as other species for over 100 years.

In a study published in the open access journal ZooKeys, scientists Dr. Nathan Whelan, U.S. Fish and Wildlife Service, Dr. Paul Johnson and Jeff Garner, Alabama Department of Conservation and Natural Resources, and Dr. Ellen Strong, Smithsonian Institution National Museum of Natural History, tackled the identity of the Painted Rocksnail, a small federally threatened species native to the Mobile River basin in Alabama.

Freshwater snails are notoriously difficult to identify, as the shells of many species can look very similar. Keeping this in mind, the researchers began to notice that many shells identified as the Painted Rocksnail in museums around the world were misidentified specimens of the Spotted Rocksnail, another snail species found in Alabama.

After examining shells at the Academy of Natural Sciences of Philadelphia, Museum of Comparative Zoology at Harvard, National Museum of Natural History, North Carolina Museum of Natural Sciences, Florida Museum of Natural History, and Natural History Museum in London, in addition to hundreds of hours of their own sampling throughout the Mobile River basin, the authors determined that all previous reports of the Painted Rocksnail from outside the Coosa River system were mistakes.

Despite the Painted Rocksnail dwelling in well-studied rivers near large population centers, mistaken identity of the species has persisted almost since the species was described back in 1861 by Isaac Lea.

Only after careful examination of shells collected in the last 150 years and analyses of live animals were the researchers able to confidently determine that the Painted Rocksnail never occurred outside the Coosa River system.

The study has implications for the conservation of the Painted Rocksnail, as the species was historically more restricted than previously thought. Recent surveys by the authors only found the species in small stretches of the Coosa River, Choccolocco Creek, Buxahatchee Creek, and Ohatchee Creek.

In conclusion, the authors note the importance of natural history museums and the importance of studying snails in the southeastern United States.

“Without the shells stored in natural history museums we would have never been able to determine that the supposed historical range of the Painted Rocksnail was incorrect, which could have resulted in less effective conservation efforts for an animal that is very important to the health of rivers in Alabama,” they say.

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Original Source:

Whelan NV, Johnson PD, Garner JT, Strong EE (2017) On the identity of Leptoxis taeniata – a misapplied name for the threatened Painted Rocksnail (Cerithioidea, Pleuroceridae). ZooKeys697: 21-36. https://doi.org/10.3897/zookeys.697.14060

New land snail species from Australia shows dissection not necessary to identify molluscs

Dissection might prove unnecessary when identifying new molluscs after scientists Corey Whisson, Western Australian Museum, and Dr Abraham Breure, Naturalis Biodiversity Centre, the Netherlands, and Royal Belgian Institute of Natural Sciences, Belgium, described a previously unknown land snail based on its genitalia, yet without damaging the specimen in the slightest. The new species is published in the open access journal ZooKeys.

The biologists described the first new Australian land snail species of this family for the last 33 years thanks to micro-computed tomography (micro-CT) and reconstruction with specialised software. This novel method, likely applied for identification of molluscs for the first time in history, uses X-rays to create cross-sections of the genitalia, so that a 3D model can be created without damaging the specimen. This can be then compared to known related taxa’s genitalia in order to show if there are enough differences to prove species delimitation.

The scientists note that despite the satisfying results, micro-CT is time-consuming and “quite laborious” approach. “However, in the case of a single or just a few specimens, this may be an alternative to destructive dissection,” says Dr Abraham Breure in his personal blog.

The new land snail, called Bothriembryon sophiarum after Dr Abraham Breure’s wife Sophie J. Breure and Corey Whisson’s first daughter Sophie Jade Whisson, can only be found along a 180-kilometre line running across the escarpment and cliff tops of the Baxter Cliffs and Hampton Ranges in Western Australia. Given its restricted distributional range, it is considered a short-range endemic.

The mollusc is characterised with a slender high-spired shell, built specifically for the demanding nature of its habitat. Dwelling in rocky limestone substrate, which is often fractured with narrow cracks and fissures, the snail has developed a slender shell, so that it can move easily through cavities and under rocks. On the other hand, being predominantly cream in colour with reddish or greyish brown blotches, it successfully blends with the limestone.

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Original source:

Whisson CS, Breure ASH (2016) A new species of Bothriembryon (Mollusca, Gastropoda, Bothriembryontidae) from south-eastern Western Australia. ZooKeys 581: 127-140. doi:10.3897/zookeys.581.8044