Author Archives: bramb

Yucatan gastropods

A paper in the journal of the German shell collectors club by Gibb is about Mexican land snails from Yucatán and Quintana Roo.

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A two-week stay in the south-east of Mexico in the summer of 1999 was used to collect marine mollusks as well as land and freshwater gastropods. All of the localities were in the states of Quintana Roo and Yucatán. The non-marine material resulted in 28 species (4 freshwater and 24 terrestrial species) all by collecting empty shells. Various soil samples were also taken and later examined under the binocular“.

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Rerference:
Gibb, W., 2020. Nicht-maritime Gastropoden von der Halbinsel Yucatan (Mexiko). – Club Conchylia Mitteilungen 34: 17-28.

 

Slug resistant plants

An interesting paper in an unexpected journal: Capinera published about the acceptatibility of plant by a veronicellid slug. His abstract reads as follows: “Leidyula floridana (Leidy) (Gastropoda: Veronicellidae) has long been known to be a plant pest in the Caribbean region and southern Florida, though its range has expanded to include northern Florida, other Gulf Coast states, and Mexico. It is nocturnal, and often overlooked as a source of plant damage. Although polyphagous, it does not feed on all plants, and it is desirable to know what bedding plants will likely be damaged by this common herbivorous slug. To identify readily accepted bedding plants, I conducted a series of comparative trials of 7 d duration to assess the acceptance of 30 commonly grown bedding plants relative to French marigold, a plant that is commonly fed upon by slugs and snails. Several commonly grown bedding plants were shown to be very susceptible to feeding injury. In a second set of 7-d trials, I compared 14 plants from among those that were not readily accepted in the first set of trials to determine if they would remain poorly accepted when not provided with favored food. In the second set of trials, the levels of herbivory shown in the first trials were maintained, demonstrating that some bedding plants are not acceptable to L. floridana even when the slugs do not have access to acceptable food. Thus, a list of readily available bedding plants that resist herbivory by this slug has been determined, providing gardeners with slug-resistant choices. The most unacceptable species (damage rating = 1.00) were: lantana (Lantana camara L.; Verbenaceae), tickseed (Coreopsis spp.; Asteraceae), torenia (Torenia fournieri Linden ex E. Fourn.; Linderiaceae), angelonia (Angelonia angustifolia Benth.; Plantaginaceae), and snapdragon (Antirrhinum majus L.; Plantaginaceae). Additional plant species that were not very acceptable (damage rating of between 1.00 and 1.50) were blue daze (Evolvulus glomeratus Choisy; Convolvulaceae), dusty miller (Centaurea cineraria [L.] Jacq. ex Nym.; Asteraceae), viola (Viola hybrid; Violaceae), celosia (Celosia argentea L.; Amaranthaceae), and geranium (Geranium spp.; Geraniaceae). In contrast, plant species that seem to be at considerable risk of damage (damage rating 3 to 5) by L. floridana were: French marigold (Tagetes patula L.; Asteraceae), Madagascar periwinkle (Catharanthus roseus [L.] G. Don; Apocyanaceae), coleus (Plectranthus scutellarioides [L.] R. Br.; Laminaceae), petchoa (Petunia × Calibrachoa; Solanaceae), zinnia (Zinnia elegans Jacq.; Asteraceae), polka dot plant (Hypoestes phyllostachya Baker; Acanthaceae), chrysanthemum (Chrysanthemum morifolium Ramat; Solanaceae), petunia (Petunia spp.; Solanaceae), Stokes’ aster (Stokesia laevis [Hill] Greene; Asteraceae), scarlet sage (Salvia splendens Sellow ex Nees; Lamiaceae), butter daisy (Melampodium paludosum Kunth; Asteraceae) and verbena (Verbena spp.; Geraniaceae). A few species were intermediate in susceptibility, namely: impatiens (Impatiens hawkeri W. Bull; Balsamaniaceae), wax begonia (Begonia × Semperflorens × Cultorum; Begoniaceae), sweet potato vine (Ipomoea spp.; Convolvulaceae), firecracker flower (Crossandra infundibuliformis [L.] Nees; Acanthceae), sweet William (Dianthus barbatus L.; Caryophyllaceae), pansy (Viola × Wittrochinana; Violaceae), purslane (Portulaca oleraceae L.; Portulacaceae), and alyssum (Lobularia maritima [L.] Desv.; Brasscaeae)“.

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Although primairily aimed at gardeners it seems, this might be interesting for related species. And perhaps even slugs from other families which iare known as pests might be tested in a similar way.

Reference:
Capinera, J., 2020. Acceptability of bedding plants by the leatherleaf slug, Leidyula floridana (Mollusca: Gastropoda: Veronicellidae). – Florida Entomologist 103(1): 80-84.

 

New Radiodiscus

Freshly pressed: a paper by Mike Rutherford describing a new species from Trinidad. “Radiodiscus hollidayi, a new species of Charopidae, is described from the island of Trinidad, Trinidad and Tobago. The description is based on conchological features alone: a tiny discoid shell with a distinct protoconch with 6–8 cordlets, fine ribs on the teleoconch, and a deep umbilicus. The snail is found in leaf litter and humus in a variety of forest habitats across Trinidad. A table compares a common set of measurements and characters across 27 other species of Radiodiscus“.

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A nice addition to the fauna of Trinidad, which still deserves an updated checklist on which the author is working.

Reference:
Rutherford, M.G., 2020. A new species of Radiodiscus (Gastropoda: Eupulmonata: Charopidae) from Trinidad and Tobago. – Archiv für Molluskenkunde 149(1): 67-74.

New paper: Pfeiffer bibliography

Just published: the bibliography of Louis Pfeiffer. “Carl Georg Ludwig Pfeiffer (1805–1877) was one of the most productive authors on (mainly non-marine) molluscs during the mid-19th century, describing an estimated 3,000 taxa. As a first step in making his legacy accessible, we present a bibliography of his malacological publications (452 items in total). His serial books and journal publications are listed separately, and we present a collation of the Malakozoologische Blätter and Malakozoologische Blätter: Neue Folge“.

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The next step will be an inventory of all species described from the Cuming collection.

Reference:
Neubert, E., Breure, A.S.H., Ablett, J.D. & Bank, R.A., 2020. The malacological contributions of Louis Carl Georg Pfeiffer (1805–1877): a bibliography, with a collation of the publication dates of the Malakozoologische Blätter. – Archiv für Molluskenkunde 149(1): 75-102.

Exotic non-marine species of Hispaniola

Just published by Agudo-Padrón is a paper on introduced non-marine species on the island of Hispaniola.

With the invaluable participatory assistance and support of local researchers, naturalists and collaborating field informants, Project AM has been developing modest taxonomic, bioecological and conservation research on the “non-marine alien molluscs” present in the Caribbean island territory of the “La Española” (Hispaniola), with special emphasis on non-native species introduced (intentional or accidentally) into their environment, so far a general total of 36 terrestrial and freshwater species (34 gastropods & 2 bivalves) have been inventoried, included in 31 genera and 21 families“.

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There is no summarising table and I spotted two dubious records: Bulimulus diaphanus and Bulimulus guadalupensis are both listed as introduced, based on a reference and record from a museum [Refs.: FMNH (s/d a); Grego & Steffec (2006: 13)]. In my 1974 paper on Bulimulus I already showed that both species have been reported on the island based on historical records, hence the listing as exotics without further sound evidence seems unwarranted.

Reference:
Agudo-Padrón, I., 2020. Moluscos exóticos no marinos “introducidos” en la isla caribeña de La Española (Hispaniola), Grandes Antillas: una aproximación a su conocimiento. Revista Minerva (San Salvador) 3(1): 129-138.

 

Forming a species name

While this is food for few, the subject may be interesting enough for those who find it cumbersome to dig through the rules of the ICZN Code when they need to name a new taxon. Vendetti & Garland has just published a practical guide, stating “The formation of scientific names for species may be challenging for modern systematists without a background in Latin or familiarity with the International Code of Zoological Nomenclature. Therefore, presented here are 10 pragmatic and simplified strategies for creating zoological species names. They are intended to demystify the derivation and construction of species names and facilitate the process of naming species for a broad audience of zoologists working in systematics”.

Their 10 strategies are the following:
1. As a Latin singular or plural noun in the genitive case;
2. As a Latin singular present participle active (PPA) in the nominative case;
3. As a Latin singular noun in the nominative case used in apposition;
4. As a non-Latin singular noun used in apposition;
5. Named after a person or persons, as a Latin singular or plural noun in the genitive case;
6. As a Latin singular adjective in the nominative case;
7. As a Latin singular perfect passive participle (PPP) in the nominative case;
8. For a geographic name, as a Latin singular adjective in the nominative case;
9. As compound word composed of Latin + Latin, Greek + Latin, or Greek + Greek word elements;
10. As an arbitrary combination of letters, singular or plural.

For each strategy they provide a clear explanation with examples from different phyla, and a practical application. In several cases with further examples, like this:

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Although it requires some sensitivity for linguistics, the overall impression is that with this paper naming a new taxon is do-able, even for those who did not have classes Latin and Greek at school. In this context I also like to draw attention to the paper ‘A name is a  name is a name’ by Peter Dance, who offers 19 additional viewpoints to naming a species.

References:
Dance, S.P., 2009. A name is a name is a name: some thoughts and personal opinions about molluscan scientific names. Zoologische Mededelingen Leiden 83(7): 565-576.
Vendetti, J.E. & Garland, R., 2020. Species name formation for zoologists: a pragmatic approach, Journal of Natural History 53(47-48): 2999-3018.

 

Annulariid phylogenetics

A recent paper by Watters et al. gives important insight in the relation of a group from the Annulariidae. Their abstract is as follows: “The subfamily Abbottellinae of the Annulariidae has been recognized as a speciose group in northern Hispaniola. This study, using phylogenetic (COI, 12S, H3), radular, and conchological characteristics, compared this group to other non-Hispaniolan annulariids to determine their wider associations and potential origin. Results indicate that the subfamily is related to the eastern Cuban Annularisca sensu lato and that genus should be moved to the Abbottellinae. The group dates from the time when eastern Cuba and northern Hispaniola were in close contact prior to tectonic movement. This is the first such zoo- geographic connection reported for the family. The subfamily is not related to any Jamaican taxa tested. The Abbottellinae also do not occur on the southern Tiburon/Barahona peninsulas of Hispaniola, which has a different geologic history from the north. The eastern Cuban and Bahamian genus Opisthosiphon sensu lato was also shown to be a member of the subfamily. The nominal genus Abbottella is further divided into new genera based on these results. The new genera Abbottipoma, Arenabbottella, Microabbottella, and Preclaripoma are described. The new species Rolleia simonaikeni is described, and Petasipoma is synonomized with Rolleia.“.

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Another paper from this very productive lab, of which its leading figure Tom Watters recently died. It shows how the molecules combined with the external morphology presents new insights in the taxonomy of a group and also elucidates the evolution and relationships with other Annulariids.

Reference:
Watters, G.T. et al., 2020. The subfamily Abbottellinae (Gastropoda: Annulariidae): origins, associations, and a review of the Hispaniolan taxa. – The Nautilus 134(1): 1-34.

Variability of Bostryx

Miranda published new data on the anatomy and shell shape variability of a Bostryx species. Her abstract reads as follows:
Introduction: The gastropod Bostryx torallyi shows high variability in shell shape and coloration. Subspecies of this organism have been described based on shell characters but, since they were slightly different, they were synonymized afterwards. Until now, shell variability has been analyzed only descriptively and its anatomy is still unknown.
Objective: In this study, I provide anatomical information of B. torallyi and apply a geometric morphometric analysis to evaluate the shell shape variation among specimens.
Methods: To accomplish this, type material and numerous lots were examined and dissected out. Additionally, relative warp analysis, based on 9 landmarks in ventral view of the shell, was performed using 80 specimens of 9 localities from Bolivia and Argentina.
Results: According to our results, geometric morphometrics is a suitable method to evaluate differences in shell shape among localities; for instance, distinctions in the shell were noticeable between gastropods of low and high altitudes. On the other hand, it was established that the coloration of this species is independent of large-scale factors since the examined specimens came from environments with similar conditions. Furthermore, the sculpture of the protoconch and anatomy of B. torallyi coincided with the other Argentinian species of the genus.
Conclusions: Therefore, I concluded that a geometric morphometric analysis of shell shape is a good complement to traditional qualitative description of the characteristics of the shell in this species
“.

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As this study shows, Bostryx species can be very variable in their shell shape and colouration, with their anatomy still being the same. The study indicated that altitude is possibly related to the shell shape, but this needs confirmation from material sampled in the wider distribution area.

Miranda, M.J., 2020. Anatomy and shell shape variability in a land snail Bostryx torallyi (Stylommatophora: Bulimulidae). – Revista de Biologia Tropical 68(1): 218-229.

Defecation behaviour

A short research note was recently published by Carvalho & Oliveira. It is about the defecation behaviour of a terrestrial snail from Brazil, Cochlorina aurisleporis (Bruguière, 1792).

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After noting the overall scarcity of data in literature on this behaviour in many animals, the authors describe the process in this arboreal snail, which uses it muscles to form a more or less spherical pellet and finally drops the pellet onto the substrate beneath. They suggest as hypothesis to explain this behaviour that it may be a strategy to prevent detection by chemically oriented predators. Although this hypothesis is interesting, it would need further testing in the field. For a start, the predators of this species are unknown as the biology of Neotropical land snails is hardly documented in literature. The authors also made a statement its distribution, viz. “a purported (and unexpected) disjunct distribution”, being known from Madagascar and Brazil. It is simply based on an erroneous original locality in Bruguière (in the 18th and 19th century species were often described based on material collected by others and many times with vague, imprecise or even erroneous localities). Cochlorina aurileporis is purely a Brazilian species; it is unfortunate that the reviewers have overlooked this.

Reference:
Carvalho de Lima, T. & Oliveira, C.D. de Castro, 2020. Unusual shaping: The defacation bahavior in Cochlorina aurisleporis (Bruguière, 1792) (Gastropoda: Bulimulidae). – The Nautilus 134(1): 57-59.