The Vegetation of South Africa, Lesotho and Swaziland

The Marine Flora and Fauna of Esperance, Western Australia Volume 2

Molecular phylogeny and revised classification of the Buccinoidea (Neogastropoda)

The radula, a chitinous membrane with embedded tooth rows, is the molluscan autapomorphy for feeding. The morphologies, arrangements and mechanical properties of teeth can vary between taxa, which is usually interpreted as adaptation to food. In previous studies, we proposed about trophic and other functional specialisations in taenioglossan radulae from species of African paludomid gastropods. These were based on the analysis of shape, material properties, force-resistance, and the mechanical behaviour of teeth, when interacting with an obstacle. The latter was previously simulated for one species (Spekia zonata) by the finite-element-analysis (FEA) and, for more species, observed in experiments. In the here presented work we test the previous hypotheses by applying the FEA on 3D modelled radulae, with incorporated material properties, from three additional paludomid species. These species forage either on algae attached to rocks (Lavigeria grandis), covering sand (Cleopatra johnstoni), or attached to plant surface and covering sand (Bridouxia grandidieriana). Since the analysed radulae vary greatly in their general size (e.g. width) and size of teeth between species, we additionally aimed at relating the simulated stress and strain distributions with the tooth sizes by altering the force/volume. For this purpose, we also included S. zonata again in the present study. Our FEA results show that smaller radulae are more affected by stress and strain than larger ones, when each tooth is loaded with the same force. However, the results are not fully in congruence with results from the previous breaking stress experiments, indicating that besides the parameter size, more mechanisms leading to reduced stress/strain must be present in radulae.

/pdf/finite-element-analysis-relating-shape-material-properties-1olenyl78z.pdf

Finite element analysis relating shape, material properties, and dimensions of taenioglossan radular teeth with trophic specialisations in Paludomidae (Gastropoda).

A review of the land snail faunas of the European Cenozoic – composition, diversity and turnovers

The genus Afrodonta s. lat. is shown to comprise several lineages with distinctive shell characters primarily associated with the microsculpture of the protoconch and teleoconch, and the manner in which the apertural barriers are deposited. These lineages comprise Afrodonta s. str. and five new genera: Amatholedonta gen. nov., Biomphalodonta gen. nov., Costulodonta gen. nov., Iterodonta gen. nov. and Phialodonta gen. nov. Twelve new species are described, doubling the diversity of aperturally dentate charopid snails known from southern Africa. All new species are narrow-range endemics. A new subspecies of one of the more widely distributed species of Afrodonta s. str. is also described. Keys to genera and species are provided. New species and subspecies: Afrodonta geminodonta sp. nov., Af. inhluzaniensis leptolamellaris subsp. nov., Af. mystica sp. nov., Af. pentodon sp. nov., Amatholedonta fordycei gen. et sp. nov., Biomphalodonta forticostata gen. et sp. nov., Costulodonta bidens gen. et sp. nov., C. pluridens gen. et sp. nov., Iterodonta ammonita gen. et sp. nov., Phialodonta agulhasae gen. et sp. nov., P. atromontana gen. et sp. nov., P. aviana gen. et sp. nov. and P. rivalalea gen. et sp. nov. New synonyms: Afrodonta bilamellaris londonensis Solem, 1970 = Afrodonta bilamellaris Melvill & Ponsonby, 1908. New combinations: Afrodonta acinaces Connolly, 1933, Afrodonta burnupi Connolly, 1933 and Afrodonta trilamellaris Melvill & Ponsonby, 1908 are transferred to Costulodonta gen. nov.; Afrodonta bimunita Connolly, 1939 is transferred to Amatholedonta gen. nov.; Afrodonta introtuberculata Connolly, 1933 and Afrodonta perfida Burnup, 1912 are transferred to Phialodonta gen. nov.

Revision of the aperturally dentate Charopidae (Gastropoda: Stylommatophora) of southern Africa – genus Afrodonta s. lat., with description of five new genera, twelve new species and one new subspecies

The gastropod radula exhibits exceptional morphological variability. Despite this enormous diversity, the main patterns of synthesis of the teeth and radula membrane, characteristic of different groups can be identified. The rhipidoglossan radula contains numerous teeth in each transverse row and was found in phylogenetically distant groups of Gastropoda. Studying radula formation through stages of ontogeny in species with this type of radula is important in determining the main patterns of radula formation in gastropods. We studied the formation of the radula during development of one species of trochid vetigastropod, Margarites helicinus, using light and electron microscopy as well as confocal laser scanning microscopy. The adult radula is formed in the blind end of the radular sac, which bifurcates into two horns in vetigastropods. The numerous marginal teeth are synthesized in these horns while the central and lateral teeth form in the region where the horns fuse. This morphology of the formation zone appears to be a common pattern for all vetigastropods. The juvenile radula of M. helicinus consists of seven teeth per transverse row and its formation in the radular sac differs significantly from that in the adult. In the juvenile, the formation zone of the radular sac is not split into two horns, and the teeth and radular membrane are synthesized by relatively few, uniform cells. This organization of the larval radular sac is thought to represent a widely occurring larval pattern potentially present in all groups of gastropods. It is associated with early formation of all organs by few cells rather than representing a phylogenetic trait.

The rhipidoglossan radula: Formation and development in Margarites helicinus Phipps, 1774 (Trochoidea, Vetigastropoda).

The radula is the basic feeding structure in gastropod molluscs and exhibits great morphological diversity that reflects the exceptional anatomical and ecological diversity occurring in these animals. This uniquely molluscan structure is formed in the blind end of the radular sac by specialized cells (membranoblasts and odontoblasts). Secretion type, and the number and shape of the odontoblasts that form each tooth characterize the mode of radula formation. These characteristics vary in different groups of gastropods. Elucidation of this diversity is key to identifying the main patterns of radula formation in Gastropoda. Of particular interest would be a phylogenetically closely related group that is characterized by high variability of the radula. One such group is the large monophyletic superfamily Conoidea, the radula of which is highly variable and may consist of the radular membrane with five teeth per row, or the radular membrane with only two or three teeth per row, or even just two harpoon-like teeth per row without a radular membrane. We studied the radulae of two species of Conoidea (Clavus maestratii Kilburn, Fedosov & Kantor, 2014 [Drilliidae] and, Lophiotoma acuta (Perry, 1811) [Turridae]) using light and electron microscopy. Based on these data and previous studies, we identify the general patterns of the radula formation for all Conoidea: the dorsolateral position of two groups of odontoblasts, uniform size, and shape of odontoblasts, folding of the radula in the radular sac regardless of the radula configuration. The morphology of the subradular epithelium is most likely adaptive to the radula type.

Radula formation in two species of Conoidea (Gastropoda).

The rhipidoglossan radula, which is characterized by presence of a central tooth, several lateral teeth, and numerous (more than 10) long marginal teeth in each transverse row, is found in three different subclasses, that is, Vetigastropoda, Neritomorpha and "lower" Heterobranchia. Details of radula formation and its ultrastructure have not been studied in any species with a rhipidoglossan radula. For the first time, we present such data for one vetigastropod species, Puncturella noachina. The radula itself and the radula formation zone were studied using light and electron microscopy (scanning and transmission), as well as confocal laser scanning microscopy. We identify the major features of Vetigastropoda rhipidoglossan radula formation, that is: the posterior bifurcation of the radula formation zone, creating paired horns into which the zones of formation of the marginal teeth extend; the supporting structure in the radula formation zone extends ventrally to strengthen this division; the odontoblasts of the marginal teeth form a multi-layered epithelium; membranoblasts do not differ from odontoblasts in ultrastructure; in some membranoblasts and cells of the sub- and supraradular epithelium basal bodies were found in the apical regions of the cells.

The rhipidoglossan radula: Formation and morphology of the radula in Puncturella noachina (Linnaeus, 1771) (Fissurellidae, Vetigastropoda).

Author response for "Radula formation in two species of Conoidea (Gastropoda)"

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

David G. Herbert

Author Tools

Chat about Author