Tag Archives: helicinidae

Brazilian cave snails

Another freshly pressed paper is by Salvador et al. on Brazilian cave snails. The abstract reads “A sample of land and freshwater snails, mainly pulmonates, was recently collected in caves in Goiás and Bahia states, Brazil. Twenty-one species were found in the material. The following species are reported for the first time for Goiás state: Cecilioides consobrina (Ferussaciidae), Dysopeas muibum and Stenogyra octogyra (Subulinidae), Entodina jekylli and Prohappia besckei (Scolodontidae; also reported for the first time for Bahia state), Pupisoma dioscoricola (Valloniidae). A new species from Goiás is described here-in: Gastrocopta sharae sp. n. (Gastrocoptidae). The new records and species addressed here constitute important findings, helping to fill distributional gaps and improving the knowledge of the local molluscan fauna, an essential step for future conservation efforts”.

schermafbeelding-2017-02-19-om-06-18-59

Besides the species newly reported for the two states, there are also additional records of the following land snails: Helicina angulata Sowerby, 1873 (Helicinidae), Cyclodonta sexdentata (Spix in Wagner, 1827) and Ringicella luetzelburgi Weber, 1925 (Odontotomidae), Happia glaberrima Thiele, 1927 (Scolodontidae), Allopeas micra (d’Orbigny, 1835) and Leptinaria concentrica (Reeve, 1849) (Subulinidae); five species are identified only to genus level.

This study complements earlier studies on the cave malacofauna in Brazil from part of the authors (see here and here).

Reference:
Salvador, R.B., Cavallari, D.C. & Simone, L.R.L., 2017. Taxonomical study on a sample of land and freshwater snails from caves in central Brazil, with description of a new species. – Zoosystema and Evolution, 93 (1): 193-141.

Dissertation on some Peruvian snails

This is not a new publication, but already from 2008. It is a dissertation of Samira Guevara, who graduated in 2005 in Hamburg, Germany under supervision of Prof.Dr Klaus Bandel and Dr Bernhard Hausdorf. The subject of her thesis was the systematic treatment of snails collected in and around three National Parks in Peru. As this dissertation falls into the ‘grey literature’ I pay some attention to it, despite not being very recently published. The thesis is in Spanish, with summaries in German and English.

Snails were collected in the vicinity of Moyobamba (Bosque de Alto Mayo), Tingo Maria (Parque Nacional Tingo Maria), and Cuzco (Parque Nacional Manu). In total 5000 specimens were collected, belonging to 40 families and 136 species. The thesis gives more details for the families Helicinidae (10 species), Ceresidae (3 species) and Bulimulidae (9 species).

In the family Helicinidae, three new species are described: Helicina (Concentrica) bandeli, H. (C.) peruensis, and Alcadia (Microalcadia) kasteli. As the thesis was formally published in 2008, all species should have as author “Guevara, 2008”. The following pictures provide photographs of the holotype of each species, together with the type locality and the depository mentioned in the legends (ZMH is Zoologisches Museum, Universität Hamburg):

schermafbeelding-2016-11-25-om-11-38-04 schermafbeelding-2016-11-25-om-11-38-45 schermafbeelding-2016-11-25-om-11-39-06

The type localities for Helicina (Concentricaperuensis respectively Alcadia (Microalcadiakasteli are: Dept. San Martin, Cataratas del Gera, 12 km SE Moyobamba, 500m, respectively Dept. San Martin, Cueva Huacharos de Palestina-Rioja, 44 km NW Moyobamba, 894 m.

From the nine species mentioned in the family Bulimulidae, I think three have been misidentified. Both Valentín Mogollón and I arrived at the same conclusions. We will report on these in a later stage.

 

Reference:
Guevara, S., 2005 [2008]. Estudio taxonómico y systemático de las familias Helicinidae y Ceresidae (Mollusca: Gastropoda: Neritopsina) y el género Drymaeus (Gastropoda: Pulmonata: Bulimulidae), en tres zonas de la Reserva Amazónica de Perú. Thesis Universität Hamburg, 2005 (unpublished) / Berlin, Verlag im Internet, 2008.

Bahia snails

Recently Alex Popovkin send me some new photos of snails he found alive during his botanical wanderings. As always these pictures don’t allow for definite identifications, but here is my best guess.

1-P1560547 2-P1560548 3-P1560550 4-P1560552 5-P1560553

Helicina angulata Sowerby, 1873

1-P1560554 2-P1560555 3-P1560556 4-P1560558

 

A Rectartemon species, possibly R. iguapensis (Pilsbry, 1930) or R. piquetensis (Pilsbry, 1930).

A big thanks to Alex for sharing…

New snails from Brazil, Edo. Tocantins

The Brazilian state of Tocantins is relatively less-known, partly due to being a split-off of Goiás state. Since its Cerrado domain has been poorly studied, a paper by Salvador et al. (2015) is a welcome addition to our knowledge.

A sample of land snails, mainly pulmonates, was recently collected in southeastern Tocantins state, Brazil, close to the border with Bahia state. The following species were found in the material, all of them are reported for the first time from Tocantins: Helicina schereri (Helicinidae); Solaropsis fairchildi and Solaropsis rosarium (Camaenidae); Anostoma rossiCyclodontina cf. gemellata and Cyclodontina sectilabris (Odontostomidae); Drymaeus poecilus and Naesiotus carlucioi (Bulimulidae); Streptaxis luetzelburgi (Streptaxidae); Megalobulimus conicus (Strophocheilidae); Beckianum cf. beckianum (Subulinidae). Additionally, Drymaeus dakryodes sp. nov. is formally described herein. The new records and species addressed here constitute important findings, helping to fill distributional gaps and improving the knowledge of the local molluscan fauna. This is an essential step for future conservation efforts.

Salvador etal 2015 f15-23

The new Drymaeus species was found at Taguatinga, 12º21’54”S 46º21’39”W, ~870m. The holotype (fig. 15-16) is MZSP 114874. The specimen of Beckianum beckianum is a sinistral shell, and other sinistral specimens have been reported from Central America.

Reference:
Salvador, R.B., Cavallari, D.C. & Simone, L.R.L., 2015. Taxonomical study on a sample of land snails from southeastern Tocantins State, Brazil, with description of a new species. – Journal of Conchology 42: 67-78.

Santa Catarina new records

Agudo et al. (2014) published nine new records for the fauna of the State Santa Catarina in Brazil.

The following taxa are concerned:
Family Helicinidae
Helicina schereri F. Baker, 1913
Family Assimineidae
Assiminea sp.
Family Subulinidae
Lamellaxis clavulinus (Potiez & Michaud, 1838)
Lamellaxis (Leptopeas) cf. mizius Marcus & Marcus, 1968
Family Bulimulidae [Amphibulimidae]
Plekocheilus (Eurytus) sp. [the specimen shown is mentioned as P. aff. rhodocheilus (Reeve, 1849) in my previous post]
Rhinus cf. longisetus (Moricand, 1846)
Family Amphibulimidae [both Rhinus and Simpulopsis are now placed in the Simpulopsidae sensu Breure & Romero, 2012]
Simpulopsis cf. ovata (Sowerby, 1822)
Family Megalobulimidae
Megalobulimus klappenbachi Leme, 1964
Family Charopidae
Zilchogyra cleliae Weyrauch, 1965

Agudo ea 2014f7

Reference:
AGUDO-PADRÓN, A.I.; LUZ, J.S.; FUNEZ, L.A.; ZERMIANI, A.E., 2014. Nine new records to inventory of continental mollusc species from Santa Catarina State, Central Southern Brazil. Brazilian Journal of Biology Sciences, 1(1): 15-20. Available at: http://revista.rebibio.net/v1n1/3543-4376-01-03.html

Diversity of Helicinidae

Although already presented at the “Magnitude of molluscan diversity – the known and the unknown” Symposium held at the 78th meeting of the American Malacological
Society (2012), Ira Richling’s excellent paper on diversity of the Helicinidae was recently published (Richling, 2014).

Richling2014f2

Presenting a history of helicinid research starting in 1801 (the first taxon described was a Jamaican species), she has analysed the development of the diversity through time and also a number of revisions to compare the number of accepted (sub)species to available names. Under ‘Drawbacks in exploration’ several aspects (listed below in the abstract) are extensively discussed, which have an importance beyond the scope of the paper.

It would be interesting to explore these issues for other (large) land snail families in the (Neo)tropics. One of these issues is the “limited availability of wet preserved material”, which is quite crucial to make advances both in morphological and molecular studies. Unfortunately, the forthcoming implementation of the Nagoya Protocol (cf. Renner et al., 2012) makes things probably worse and opens up the possibilities for unwarranted claims from local scientists and license authorithies for financial expenditures, and more (examples are known of claimed co-authorship for several papers without any content contribution). Given the ongoing crisis in natural history museums, this is an avenue leading to disasters.

Richling2014f4

The full abstract of the paper reads: “Helicinids represent a family of tropical land snails with a distribution range limited to the subtropical and tropical zones of the New World, Australasia, and the Pacific. For an estimate of diversity in this poorly systematically revised group, the total number of described taxa was determined and used for calculations based on analyses of selected case studies with regard to the percentage of valid and new taxa.
Extensive bibliographic searches identified about 1,250 available names, regardless of rank, that were described from 1801 onward. Fiftyeight percent of the names represent New World taxa whose majority (63%) was created before 1880 while the intensive study in most of the
Australasian and Pacific areas started much later with the bulk of taxa described between 1880–1930. An analysis of the distribution of the type localities and the times of descriptions allowed for identification of scarcely- and well-studied areas.
Eight potentially representative case studies of major revisions were compared with respect to changes in described versus “true” diversity. The geographic range covered Costa Rica, Cuba, Jamaica, Lesser Antilles, New Caledonia, northeast Australia, and the Hawaiian and Gambier
Islands. In these studies approximately half of the available names were regarded as synonyms (range from 37 to 72%). On the other hand, 36 to 41% of the recognized diversity represented new species depending on whether a more lumping or splitting approach was considered, the
latter simulated by simply counting subspecies as equal units of diversity. The amount of new taxa ranged from 2% (Cuba) to 90% (Gambier Islands). Under the assumption that six of the studies were representative throughout the area of distribution, worldwide diversity would
range from 770 to 1,140 species or up to 1,400 species if the studies from the Australasian-Pacifi c area were realistic. Although obviously poorly studied, in comparison with an estimate for all continental molluscs of Mexico and Central America by Thompson (2011), helicinids
would still be among the better documented snail families for this region.
The following aspects and their consequences are discussed as most significant drawbacks in the exploration of helicinids: questionable systematic concepts above species level; limited recognized differentiating characters and convergence; species complexes and last, massive
habitat loss, increasingly fragmented distribution and extinction. Another practical aspect is the rather limited availability of wet preserved material”.

References:
Renner, S.C. et al., 2012. Import and export of biological samples from tropical countries—considerations and guidelines for research teams. – Organisms, Diversity & Evolution 12: 81–98.
Richling, I., 2014. Poorly explored jewels of the tropics: Estimating diversity in non-pulmonate land snails of the family Helicinidae (Gastropoda: Neritopsina). – American Malacological Bulletin 32: 246–258.

American Malacological Society meeting

With the AMS (and COA) meetings scheduled for next week, the book with the program and abstracts for the AMS meeting is now available. Several topics of interest to Neotropical land snails are highlighted here.

Phylogenetics and evolution of Jamaican Pleurodontidae 

Makiri Sei & Gary Rosenberg

The pulmonate family Pleurodontidae (formerly placed in Camaenidae) is one of eight endemic-rich families of land snails in Jamaica. Thirty endemic Jamaican pleurodontid species are currently classified in the genera Pleurodonte, Dentellaria, Thelidomus and Eurycratera, but their evolutionary history within the family has not been rigorously examined with molecular phylogenetics. We obtained partial sequences of mitochondrial cytochrome c oxidase subunit II (COII) gene, 16S ribosomal RNA (rRNA) gene, and nuclear 28S rRNA gene from 70 Jamaican pleurodontid individuals, 24 non-Jamaican pleurodontid individuals, and twelve outgroups including Cochlicellidae, Helminthoglyptidae, Hygromiidae, Sagdidae, and Scolodontidae.

Phylogenetic analysis strongly supports the monophyly of Jamaican species and the polyphyly of the genus Pleurodonte. Jamaican Pleurodonte did not group with Pleurodonte (sensu stricto) from the Lesser Antilles, but with Dentellaria from Jamaica. These results suggest that a single colonization event with subsequent radiation established the Jamaican pleurodontid fauna. The large degree of sequence divergence within some Jamaican pleurodontid species suggests some taxa described at the varietal level need to be elevated to full species status. In addition, some supposed ingroup taxa (Caracolus, Solaropsis, Zachrysia and Parthena) grouped strongly with Jamaican Sagdidae. This suggests that Pleurodontidae is not monophyletic and that the subfamily Polydontinae might be more closely related to Sagdidae. 

Exploration at the verge of extinction ??? estimating diversity in the tropical land snail family Helicinidae (Neritopsina)

Ira Richling

Helicinids represent a family of classic tropical land snails with a distribution range limited to the subtropical and tropical zones of the New World, the Australasian and the Pacific region. Hot spots of helicinid diversity are typically found on different island sites, e. g. the Greater Antilles and certain Indo-Pacific islands.

Although not as severely threatened as other tropical land snail families such as Endodontidae, Partulidae and Achatinellidae, the Helicinidae are faced with extinction in some areas. As almost exclusively forest dwelling species with often high requirements for suitable habitats they suffer almost everywhere at least a dramatic loss of habitat. This not only results in limited available material, but highly fragmentary data on distribution, the documented range of variation etc.

Against this background, and based on case studies in the different parts of the world (Costa Rica, the Lesser Antilles, New Caledonia and Pacific islands), specific and general challenges in approaching diversity estimates are discussed. A critical review of the available data from the different regions will be presented with a new estimate of the worldwide diversity, which will help to expose poorly studied areas and highlight the main sources of new species.

In helicinids, the greatest specific drawbacks to systematic work, and thus to judging diversity, include: a limited number of recognised differentiating characters; still-questionable systematic concepts and the absence of a robust higher phylogeny, and intergrading shell morphologies and multiple cases of convergence, not only in shell shape but in radula characteristics as well. An annotated outline of the past research on Helicinidae will round off the presentation. 

Gal??pagos bulimulids: diversification amongst a vanishing tribe

Christine E. Parent

Why are island systems inhabited by remarkable adaptive radiations? Finches in Gal??pagos, Honeycreepers in Hawaii, Cichlids in the Great Lakes of East Africa–these species display a range of phenotypic variation equivalent to that of many vastly larger taxonomic groups. On Gal??pagos, bulimulid land snails have diversified to an unprecedented density of species richness. In this group there are over 70 described species representing a vast array of variation in form and ecology. This variation is the result of evolution in a fragmented landscape. Phenotypic diversity in these snails results from the combination of within-island speciation, between-island colonization and extinction.

During this talk I will first present a general overview of my research work on Gal??pagos bulimulid land snails. I will then focus on my latest work which aims at bridging the gap between the observed patterns of biodiversity at and above the species level and our understanding of how diversification proceeds at the population level. Although the patterns of adaptive radiations are increasingly well described, and the process of intraspecific diversification leading to speciation is better understood, the link between them remains to be studied in detail. 

Populations of abnormally-shelled giant African snails Lissachatina fulica (Bowdich) in Barbados

Anton Norville & Angela Fields

The giant African snail, Lissachatina fulica (Bowdich 1822), first reported from the parish of St. Michael, Barbados in 2000, is now well established in all parishes on the island.

In 2006, specimens of giant African snails possessing abnormally shaped shells were observed. A survey of the island was initiated in 2007 to document the distribution of populations of abnormally shelled (AS) snails. Collection of snails were made at 16 sites to determine the prevalence of AS-snails, the shell lengths of snails displaying shell abnormalities and the whorl at which abnormalities could first be seen. To catalogue the types of abnormality observed, 746 shells were inspected and differences from Bequaert???s description of the shell of Lissachatina fulica were noted.

Of the 78 locations surveyed, 32% were found to have populations containing abnormally shelled snails. The prevalence of AS-snails in these populations ranged from 1% to 70%. The first appearance of an abnormality could be as early as in the third whorl of a neonate shell (shell length, 9 mm) or as late as in the eighth whorl of an adult shell (shell length, 103 mm). Abnormalities found included a reflexed apex, uneven whorls, a disjunct body whorl, an umbilicus, two outer lips and a non-truncated columella.

An ereynetid mite has been found at all sites where AS-snails are present. An investigation as to whether this mite is implicated in the shell abnormalities seen in Lissachatina fulica is under way. 

Diversity, phylogeography and relationships of the Cerion (Gastropoda: Cerionidae) of the Dutch Leeward Islands

M. G. Harasewych

Long known for its exceptionally high diversity, the family Cerionidae ranges from the barrier islands of southern Florida to the Dutch Leeward Islands, usually inhabiting terrestrial vegetation with a few hundred meters of the shore. The nominotypical subgenus Cerion is restricted to the Dutch Leeward Islands, and separated from all living congeners by the Caribbean tectonic plate.

Nine taxa have been proposed for this fauna based exclusively on shell morphology. Several have been supported by subsequent, detailed morphometric analyses. Phylogenetic relationships of the subgenus and its constituent taxa are reviewed based on the first molecular studies of this fauna [partial 16S and CO I sequences]. Samples from the type localities of all named taxa are included in the analyses to infer patterns of interrelatedness among populations on Aruba, Cura??ao and Bonaire, and to evaluate biogeographic hypotheses. 

Morphological and molecular analysis of the Andean land slugs Colosius n. sp., a newly recognized pest of cultivated flowers and coffee from Colombia and Ecuador, and Colosius pulcher (Colosi, 1921) (Gastropoda: Veronicellidae).

Suzete R. Gomes, David G. Robinson, Frederick J. Zimmerman, Oscar Obregon & Norman B. Barr

In this study we identify a new species of Colosius, recognizing it as pest of coffee and cultivated flowers from Colombia and Ecuador. We compare it with C. pulcher, a species with which it has been confused. In order to analyze the genetic relationship of Colosius n. sp., C. pulcher, C. propinquus (currently synonymized with C. pulcher) and C. lugubris (type species), fragments of COI, 16S rRNA, and 28S rRNA genes are analyzed.

Genetic variability within Colosius n. sp. and C. pulcher is also analyzed based on COI and 16S rRNA. In Colosius n. sp. the phallus has a deep longitudinal groove from the base, near the retractor muscle, to its distal region, close to the papilla. In C. pulcher there is an oval to rectangular swelling on the basal region of the phallus. Some important differences between both species are also found in the digitiform gland and bursa copulatrix.

Colosius n. sp. is a distinct lineage within the genus Colosius. It is not a sister species of C. pulcher, which has C. propinquus as a sister species, here confirmed as valid. Colosius n. sp. is closer to the clade that includes C. pulcher and C. propinquus than it is to C. lugubris. Based on the phylogenetic reconstruction, C. lugubris is sister to all the other Colosius. Genetic diversity within Colosius n. sp. and C. pulcher is low.

We describe, illustrate and discuss the color variation, morphological similarities, diagnostic characters and variability, habitat and distribution for Colosius n. sp. and C. pulcher. Associated imports and number of interceptions per year of Colosius n. sp. by federal agricultural inspectors are also presented. 

Land mollusks in northern South America: biogeographic and ecological studies in megadiverse hotspots

Francisco J. Borrero & Timothy A. Pearce 

The terrestrial malacofauna of northern South America is very poorly known. As a team of Colombian, European, and USA scientists (6 institutions total) we are studying the land snails of Colombia to enhance knowledge of systematics, distribution, and phylogeography of terrestrial mollusks and to address broader questions regarding the origin and maintenance of Neotropical biotic diversity. We will assess relations of the northern South America fauna with those of North and Central America, the Caribbean, and the rest of South America. We focus on Colombia because (1) it is at the crossroads of multiple biogeographic provinces and of the inter-American faunal exchange that was facilitated by joining previously separated faunas at Panama, and (2) it includes two megadiverse hotspots (Biogeographic Choco and Northern Andes). Land snails are uniquely well suited for these analyses as they are ancient, diverse, abundant, and, due to their limited dispersal ability, they address our questions better than more mobile taxa.

We outline the rationale, main methodology, and preliminary results of this first modern, comprehensive survey program of any non-arthropod invertebrate animal group in Colombia and northern South America. A species accumulation curve for Colombia continues climbing steeply, indicating that many species remain to be described; a sharp climb since year 2000 (including work by us and others), shows that relatively little effort can markedly increase the known biodiversity.

Suitably collected material will allow us to (1) compare diversity and endemism in various ecosystems, (2) study influences of dispersal limitation and habitat specificity in snail distributions, (3) assess whether snails are as diverse as other invertebrates in leaf litter and canopies, (4) study how the American interchange of land snails differs from that of other groups, and (5) examine the contributions of in situ speciation and accumulation of fauna from other regions to Colombia???s land snail diversity.