Tag Archives: veronicellidae

Veronicellidae in Argentina

Santin & Miquel (2015) published recently on the family Veronicellidae in Argentina. Always a tricky family, thus it is a nice contribution to our knowledge of this fauna.

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The abstract reads:

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Reference:
Santin, R.A. & Miquel, S.E., 2015. Veronicellidae in Argentina: taxonomy, morphology and distribution. – Archiv für Molluskenkunde 144: 105–123.

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Sluggy notes

In the most recent issue of the American Malacological Bulletin two papers appeared with notes on slugs in the Neotropics.

The first paper is by Clarke & Fields, entitled Mating in Veronicella sloanii. It describes observations on the copulation of this pest species on Barbados (W.I.).

The systellommatophoran slug Veronicella sloanii (Cuvier, 1817), is a simultaneous hermaphrodite. This slug is an agricultural and horticultural pest in Barbados and several islands of the Lesser Antilles. Over the period January-July 2006 and June-August 2010, the mating behavior of this species was determined by ad libitum and focal animal sampling of captive slugs collected from six sites on the island of Barbados, supplemented by observations and length measurements of slugs seen mating in the field. Individuals of Veronicella sloanii mated reciprocally in pairs, but also in a multi-partner ring formation involving three individuals. Two stages in the mating process were identified, courtship and copulation. Courtship was short, less than two minutes in mating events that led directly to copulation (mean 1.87 minutes, range 0.25–2, N = 53). Copulation in contrast was long, lasting on average 1.03 hours (range 0.4–2, N = 40). During mating the penial gland of each partner made contact with the foot or the hyponotum of the other partner. Aggressive behavior during mating in this slug was manifested by non-mating individuals pushing themselves between mating pairs resulting in the withdrawal of the penis of the mating pairs and cessation of copulation. A strong size-assortative mating pattern was observed; individuals in mating pairs were of similar size.

The second paper by Gutiérrez et al. is about invasive species in Argentina, of which four are reported as new to the fauna.

This paper reports for the first time the occurrence of four exotic terrestrial slug species in Argentina: Lehmannia valentiana (Férussac, 1823) (Limacidae),Deroceras invadens Reise et al. 2011 (Agriolimacidae), Arion intermediusNormand, 1852 (Arionidae) and Meghimatium pictum (Stolyczka, 1873) (Philomycidae). The study is based on specimens deposited in museums in Argentina. Both the morphologic characteristics and the mitochondrial cytochrome oxidase I gene sequences were used to identify the exotic species. Phylogenetic analyses were also carried out in order to explore the location of their origins. Lehmannia valentiana had the oldest records and has been widely distributed in Argentina. Deroceras invadens and A. intermedius were found to be restricted to the southern portion of the country. Meghimatium pictum was recorded in the northwest and northeast Argentina, and the DNA sequences analyzed from this species were more closely related to specimens from the west of the Strait of Taiwan. A determination of the origin of the other species was impossible because either the sequences analyzed grouped with samples from different geographical origins or only few sequences were available for comparison. In view of the invasive potential of these slug species, the present work provides new and potentially useful DNA sequence data obtained from morphologically-confirmed specimens. Information provided from these analyses should assist in making a rapid identification of these exotic slugs by nonspecialists and governmental authorities who are responsible for managing and controlling the presence of exotic species.

Although I had expected to find some catchy photographs of these species in the field, the paper is only illustrated with phylogenetic trees. Serving their purpose within the context, maybe a suggestion for a sluggy follow-up paper of some sort that may serve as a field guide?

References:
Clarke, N. & Fields, A., 2013. Mating in Veronicella sloanii (Cuvier, 1817) (Veronicellidae). – American Malacological Bulletin 31: 235-244.
Gutiérrez Gregoric, D.E., Beltramino, A.A., Vogler, R.E., Verónica Nuñez, M.G., Gomes, S.R., Virgillito, M. & Miquel, S.E., 2013. First Records of Four Exotic Slugs in Argentina. – American Malacological Bulletin 31: 245-256.

Snail-eating snakes

Agudo-Padr??n (2012) recently published a brief overview of the preferences of snail-eating snakes in southern Brazil, belonging to the snake family Dipsadidae.

Schermafbeelding_2012-11-19_om

Snails reported to be on the digest of these snails include Veronicellidae, Bulimulidae, as well as the invasive Bradybaena similaris.

Reference:
Agudo-Pad??n, I., 2012. Brazilian snail-eating snakes (Reptilia, Serpentes, Dipsadidae) and their alimentary preferences by terrestrial mollusks (Gastropoda: Gymnophila & Pulmonata): an preliminary overview. – Biological Evidence 2: 2-3. Online available at http://bio.sophiapublisher.com/core/files/journals/40/articles/490/public/490-1615-1-PB.pdf

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.