The Influence of Morphological and Microstructural Characteristics to Land Snail Degradation in Forest Environment

Charles University, Faculty of Science Department of Invertebrate Zoology

Doctoral study programme Summary of the Doctoral thesis

Vliv morfometrických a mikrostrukturálních charakteristik na rozklad ulit plžů v lesních ekosystémech

Mgr. Dagmar Říhová

Supervisor: doc. RNDr. Lucie Juřičková, PhD.

Praha, 2018

Abstract The decomposition of land snail shell is a complex process involving a number of factors and influences, including the characteristics of conchs themselves. In particular, it is the shell size with which the progress and the rate of degradation are tightly bound. Post-mortem changes begin with the loss of the original colour and, in the case of transparent species, by the opacification of the shell wall. Subsequently, the periostracum disruption and dissolution of calcium layers occur. However, this sequence may be reversed for some small species (e.g. Columella aspera, Nesovitrea hammonis). Animals mechanically destroy empty shells, humic acids from the substrate cause their artificial dyeing. Fungal mycelium or colonies of Streptomyces grow on the surface of the conchs. The plant roots are also involved in shell decomposition. While degradation of large shells starts with periostracum disruption and subsequent ostracal dissolution, periostracum of small shells persists even after dissolution of ostracal layers. The phenomenon is caused by high resistance of the periostraca of small species. In the case of large shells, periostracum has primarily a “building” function during shell formation, and sometimes it is flaking off already during the snail's life. For small species, it is an important part of the conch and increases its durability, which is also reflected in a different course of shell decomposition. The shell size affects highly the rate of decomposition: small shells disappear very quickly, depending on the habitat type in order of months. On the contrary, large shells could persist for several years. The habitat influence is also very important. Acid and humid sites promote rapid decomposition; in dry and basic woods shells are kept relatively unchanged for several years. A unique and site-specific combination of the above-mentioned damage types, so called taphonomic signature, is created. Although the decomposition of the shells is a complex process, empty shells can provide valuable information and must not be overlooked.

Key Words Molluscan shell, calcium carbonate, periostracum, taphonomic signature, forest, SEM

Abstrakt Rozklad schránek suchozemských plžů je komplexní proces, na kterém se podílí množství činitelů a vlivů, včetně vlastností schránek samotných. Důležitá je především velikost ulity, se kterou je svázán průběh i rychlost rozkladu. Posmrtné změny začínají ztrátou původního zbarvení a u průhledných druhů zakalováním stěny schránky. Následně dochází k narušení periostraka a rozpouštění vápenatých vrstev. Tato posloupnost však v případě některých malých druhů (např. Columella aspera, Nesovitrea hammonis) může být obrácena. Živočichové mechanicky ničí prázdné schránky, huminové kyseliny ze substrátu způsobují jejich obarvování. Na povrchu schránek vyrůstají houbová mycelia či kolonie bakterií r. Streptomyces. Na rozkladu se rovněž podílí kořeny rostlin. Zatímco velké schránky se rozkládají způsobem periostrakum nejprve, periostrakum malých ulit vytrvává i po rozpouštění ostraka. Jev je způsoben vysokou odolností periostraka malých druhů. V případě velkých schránek má periostrakum především stavební funkci při tvorbě schránky a již za života plže někdy oprýskává. Pro malé druhy představuje důležitou součást schránky, která zvyšuje její odolnost, což se rovněž projevuje odlišným průběhem rozkladu. Velikost schránky ovlivňuje především rychlost rozkladu: malé schránky mizí velmi rychle, v závislosti na typu lokality i v řádu měsíců. Velké schránky naopak vytrvávají dlouho, po dobu několika let. Lokalita, na které k rozkladu dochází, je rovněž velmi důležitá. Místa značně kyselá a vlhká podporují rychlý rozklad, v lesích suchých a bazických se schránky uchovávají po několik let i v podobě relativně nezměněné. Různé lokality na schránkách zanechávají tzv. tafonomický podpis: unikátní směs výše zmíněných typů poškození. Přestože je rozklad schránek komplexní záležitostí, mohou prázdné schránky poskytnout cenné informace a nesmí být přehlíženy.

Klíčová slova Schránka, uhličitan vápenatý, periostrakum, tafonomický podpis, les, SEM

Introduction We are familiar with almost all aspects of pulmonate life: we know many about their physiology, ethology, reproduction, ecology or evolution. We learn how their shell is arranged (Cameron 1981) and discovered amazing shell shape miscellaneousness (Goodfriend 1986). Yet there is a neglected part of landsnail malacology: we haven't almost any knowledge about persistence and degradation of empty shells. What comes after land snail's death? Is the shell capable of long persistence or does it quickly vanish after the disappearance of a soft body? The information about “behaviour” of empty shells is very important for population dynamics studies or for studies about species diversity and some authors call for information about the rate and the pattern of shell degradation (Schilthuizen 2011). Despite this lack of information, the references to shell degradation, persistence and disappearance are scarce. We know that shells are under some condition capable of accumulation of the soil surface (Emberton et al. 1996, Cameron et al. 2003, Schilthuizen et al. 2003), but quick shell decay was also documented (de Winter & Gittenberger 1998, Müller et al. 2005, Ström et al. 2009). Animals were observed to enhance shell disappearance (Cadée 1999, Appleton & Heeg 1999, Graveland et al. 1994, Mänd et al. 2000, Cadée 2016). Some authors documented the influence of shell properties on shell degradation. Thick and large shells are more durable than small and brittle one (Hotopp 2002, Millar & Waite 1999, Sólymos et al. 2009). Up to our knowledge, the course and the rate of shell degradation itself were so far mentioned in malacological literature only four times: in work of Barrientos (2000), Menez (2002), Pearce (2008) and Cernohorsky et al. (2010). These four papers cover waste range of biotopes extending from tropical rainforest in Costa Rica (Barrientos 2000) through Central European fens (Cernohorsky et al. 2010) and North American temperate forests (Pearce 2008) to Mediterranean (Menez 2002) and refer about number of shell damage characteristics occurring after snail's death. Classification to six types of shell degradation types (mainly caused by predation) was published by Millar & Waite (2004) who worked in temperate canopy forest in England. Not only recent malacologists are interested in shell degradation: from palaeontological literature (e.g. Staff & Powell 1990, Perry & Smithers 2006) we are informed about the influence of habitat types and abiotic conditions on shell persistence in marine environment. Palaeontologists often consider abiotic and biotic factors influencing shell state during fossilisation as a complex forming the so called taphonomic signature. This is defined as “a set of shell alterations typical for one particular site” (Parsons-Hubbard 2005). It has been shown to indicate even small differences in chemical conditions, environmental energy and biologic activity at the burial site (Parsons- Hubbard 2005). The presence of taphonomic signatures can be expected also at the terrestrial sites, since for example soil pH and overall wetness of the site can be expected to interact to influence shell degradation. To our

knowledge, no attempt has been made to investigate the existence of taphonomic signatures on land snail shells in a terrestrial environment. Except above mentioned papers by Barrientos (2000), Menez (2002), Millar & Waite (2004), Pearce (2008), Cernohorsky et al. (2010) and our work (see below), the evidence supporting knowledge about landsnail shell degradation is missing.

Aims of the study To complete the missing evidence about landsnail shell degradation and persistence, we decide to study shell degradation in Central European forests as well as in laboratory experiments and:

(I) find out what happens with an empty shell in temperate forest environment, describe those changes precisely and reveal their possible causes

(II) if present, to describe and compare shell degradation patterns

(III) to quantify the rate of shell disappearance

(IV) to compare the taphonomic signatures of studied forest types

(V) to describe microstructural characteristics of shells and their relationship to the overall degradation pattern

Material and methods Nine model land snail species were chosen (for details, see Říhová et al. 2018). Six forest sites represent the main types of Central European forests and cover various types of water regime (from dry to seasonally flooded) and soil properties (from acid to alkaline ones). Fresh empty shells were placed in perforated plastic boxes filled with local leaf litter (four boxes to each locality). Five shells of each species (altogether 1080 specimens) were put in each box and the boxes were dig inside leaf litter and topsoil. After 6, 12, 24 and 36 months, boxes were excavated and the content was dried. Shells were picked up and photographed; their condition was checked and measured on the photographs. Subsequent multivariate analyses were performed in CANOCO for Windows 4.56; univariate analyses in the R statistical environment, version 2.10.1 (for more details, see Říhová 2018). Based on obtained results, soil moisture emerged as one of the most important environmental factor influencing shell degradation. Therefore, we study its effect in laboratory condition. Two levels of moisture (“moistened shells” and “immersed shells”) were applied to fresh, transparent shells of four species (Carychium minimum, Nesovitrea hammonis, Cochlicopa lubrica and Succinea putris). Control shells were kept in dry place. Altogether, 1290 specimens were used and condition of shells of both treatment and control group was checked each three days for ten replications. Shells were dried at room temperature for 24 hours and photographed. Again, shell pictures were checked for alteration characteristics. Obtained data were analysed in the R 2.10.1 statistical environment (see also Říhová 2018). The experiment focused on fungi colonising shell surfaces was carried out in laboratory. A modified method for the isolation of keratinophilic fungi (Orr 1969) was used: shells of Cepaea hortensis were sterilised and placed into Petri dishes filled with substratum on the surface of the litter layer using sterile tweezers. Five shells were placed in each Petri dish with the apical side facing down and in direct contact with the litter. Four forest sites from the previous study were used. Eight replicates were set up for each locality (a total of 40 shells per locality; altogether 160 shells). The dishes were kept at 15 °C in the dark and examined after four 3-month periods. The apical side was surveyed with a stereomicroscope to detect the presence of fungi; fungal structures were picked with a sterile needle, mounted in water or Melzer’s reagent and examined with a light microscope. When possible, fungi were isolated into pure culture. They were identified based on phenotypic characteristics. The identification of the fungi that were successfully isolated into pure cultures was confirmed using DNA methods. All statistical analyses, focused on similarities of fungi associations were run using CANOCO for Windows 4.56 statistical software (for details, see Říhová et al. 2014). Barrientos (2000), Hotopp (2002) and Menez (2002) discus intrinsic shell characters (especially size and shape of the conch) affecting shell persistence. However, we believe that microstructural characteristics of

periostracum and ostracum could affected shell persistence as well. To describe these characters for nine model species (and their relatives; see Říhová 2018), scanning electron microscopy (SEM) was used. Fresh empty shells of adult specimens were broken by hand using tweezers or entomological pins. Only fragments made from the last whorl were used. Suitable fragments with transverse fracture of shell wall were mounted on metal base by the use of sticky carbon tape. Before gold coating, all specimens were dried for 24 hours in room temperature. Gold spluttering was made by Bal-Tec SCD 050 machine and observation was done by SEM JEOL 6380VL microscope. Photographs of shell fractures were analysed in Image Tool 3.00 programme and the visualization was done in R 2.10.1 statistical environment (see Říhová 2018).

Results and discussion In the pilot experiment, seven basic types of shell degradation were observed (Říhová & Juřičková, submitted).

Colour changes are present as two distinct types of surface alteration: fading and artificial dyeing. Fading is represented as a loss of original pigmentation and ornamentation. It usually affects small areas of the shell surface; in extreme cases it can “erase” the original pigment ornamentation. This type of shell alteration is one of the most common and time-dependent. Fading appeared only in places with direct contact of leaf litter and/or soil particles with the shell surface and is probably caused by chemical changes induced by high moisture and low pH of the soil and leaf litter. Insolation (as documented by Menez (2002)) cannot cause this alteration. Dyeing (various shades of orange and brown) usually appears on eroded parts of the shell. It appeared in all types of forest environment and affected all model species regardless of their size or original colouration. The presumable cause of this shell alteration is an impact of soil humic acids. It is known that humic acids cause dyeing of organic materials, e.g. human hair (Hall & Packham 1965, van der Sanden 1992), and we presume their effect to shell dyeing. 7

Opacification is typical for small species (smaller than 8 mm) with transparent shell wall and occurs during early stages of degradation. Shortly after snail's death single opaque dots appear on the shell. Afterwards the dots expand into spots and in the end the whole shell is milky white and opaque (Říhová & Juřičková, submitted). Shell undergo quick opacification in highly humid environment (Říhová 2018). The real cause of opacification is unknown. We hypothesize two possible causes: degradation of organic matrix among individual crystals in the calcareous shell microstructure (as mentioned for the marine environment in Glover & Kidwell (1993)); or the growth of bacterial colonies in the shell. A mineralogical shift in crystal structure and subsequent change of the optic characteristics of the shell isn't probable. Change of aragonite to calcite is known from palaeontological studies (Yanes et al. 2008), but it usually happens on a thousand years timescale.

Loss of the periostracum manifests as periostracum deterioration followed by its separation from calcareous parts of the shell. It exposes ostracal layers and allows their further dissolution. This agrees with the findings of Hunter (1990), who observed loss of weight dependent on periostracum loss in two freshwater snails. Surprisingly, Pearce (2008) did not find any correlation between the area of periostracum loss and consequent weight loss. He probably used robust species with already slow rate of ostracal dissolution. Loss of periostracum has already been described several times (Evans 1972, Hotopp 2002, Menez 2002, Pearce 2008). In our experiment, it mainly affected large species. The probable cause of periostracum loss is an increase and/or variation of humidity and acidity of environment. Living snails actively search for a humid- stable microclimate, whereas empty shells are typically subject to humidity changes. This is in agreement with Morton's observation (2006) on mussels. Evans (1972) and others (Cameron & Morgan-Huws 1975, Davies & Grimes 1999) presume that periostracum disappears within one year after a snails' death. During the whole experiment, we never observed the complete disappearance of the periostracum from shells. The majority of investigated shells retained some parts of periostracum even after three years of burial in leaf litter.

Dissolution of ostracal layers has three distinct subtypes: pitting, holes and so called windows, i.e. holes covered by the periostracum. The initial stage of dissolution, pitting, is marked by presence of shallow depressions in the shell wall. The following stage – holes – is derived by broadening and deepening of the pits. Windows are a specific type of dissolution observed in some small species. We decided to term them windows since they are made by patches of dissolved ostracum covered by intact, transparent periostracum and strongly resemble real windows. In extreme cases (specifically in C. aspera, rarely in P. hammonis and C. lubrica; see Říhová & Juřičková, submitted), all

calcareous parts of the shell are lost and only the empty periostracum remains. Bare periostracum might undergo deformation. Dissolution is very common in shells of both size categories. It has been reported to be affected by low soil pH and high soil/leaf litter moisture (Evans 1972, Pearce 2008, Cernohorsky et al. 2010). Our data also support this explanation, since the dissolution of calcareous layers was much more common in the wet and acidic biotopes.

Mechanical fragmentation of the shell is manifested by sharp edges of broken fragments in contrast to dissolution with smooth edges of newly created holes. It can be caused both by biotic and abiotic reasons. In field experiment (Říhová et al. 2018), wild boars smashed boxes as well as shells into small pieces. These boxes are a new object in the boars' environment and thus attract their attention. Similar behaviour has been already observed (Meynhardt 1983; E. Horčičková (2010) pers. comm.). A number of other animals (for overview see Barker 2004) destroy shells in order to reach the snail's flesh, but this type of activity was irrelevant in our experimental conditions. On the other hand, the use of empty shells as a source of calcium for birds is well documented (Graveland et al. 1994, Mänd et al. 2000). An apex and mouth chipping off can be caused also by movements of the surrounding leaf litter and soil particles. When water-soaked, shells are brittle and easy to break. Apex breaking is a common type of fragmentation, caused probably also by the thinner shell wall at the apex.

On shells of all sizes we detected a specific muddy trace looking like double rail caused by association of plant root with the shell surface. Root imprints were frequent especially in acid localities. We believe that plants are able to use empty shells as calcium source and “stretch out” roots in the direction of source of deficient elements in order to increase its uptake (Hodge 2004, De Kroon et al. 2005, Morris et al. 2017).

Several types of mycelium and mycelia-related structures were observed on the surface of buried shells. They usually resemble thin fibres of various colours, or small white tufts (see Říhová & Juřičková, submitted). Those tufts are in fact actinobacterial pseudomycelia of the genus Streptomyces. When assessing this diversity in detail, around 30 morphotaxa were found (Říhová et al. 2014). A new species of soil micromycete was discovered on shell surface of Cepaea hortensis. Thanks to its specific morphology and unique substrate, it was named Pentaster cepaeophilus Koukol, 2013 (Koukol & Říhová 2013). Fungi and actinobacteria colonise outer surface of shell, but do visibly penetrate neither periostracum nor ostracum. Is seems more likely that they use empty shells as an inert surface for reaching other parts of substratum, not the source of calcium or organic compounds itself.

Two basic shell degradation patterns were observed. Large species degrade “from the outside”, with corrosion starting with disruption of the periostracum and exposure of calcareous layers. Shells of small species degrade differently. Their corrosion starts with dissolution of calcareous parts of the shell while the periostracum persists and windows arise. The area of windows may expand until calcareous parts entirely dissolve and only an empty periostracum remains (Říhová & Juřičková, submitted). Large shells have a thicker shell wall and therefore dissolution takes longer time. Disintegration of the periostracum precedes it, and we observe dissolution of calcareous layers from the outside. On the other hand, small species have thin ostracum (see Table 7 in Říhová 2018) and therefore the dissolution of shell wall from within typically precedes the loss of periostracum integrity. We also observed size-specific retention of an intact periostracum. The differing pattern of degradation in small and large snail species might be affected by different periostracum resistance in large and small species. When comparing observed rates of an intact periostracum for both groups of species after six months, periostracum of small species was well-preserved more frequently (44.7% of small shells with an intact periostracum in contrast to 8.9% of large species). After 36 months (the last time interval), 36.7% of small shells had well-preserved periostracum – in comparison with none of large shells. This observation refers to the fact that shell degradation is influenced also by shell characteristics. We believe that thickness of periostracum and microstructural architecture of shell wall are two of them (see below).

Shells of different size disappear with different rate. Small shells disappeared much more quickly than large shells and start to disappear within the first six months of burial. Large species are far more durable, and a notable decrease has not begun until 36 months after burial (for more detail, see Table 3 in Říhová et al. (2018)). This is in concordance with Hotopp’s (2002) statement that “small species disappear in a matter of months”. Observed size-specific disappearance is caused by dissolution of calcareous parts of the shell. After six months, the presence of holes (the best indicator of ostracal dissolution) is minimal. Two years after burial, holes become more frequent, and, after three years and only in some biotopes (peat-bog pine forest and alder alluvial forest), large species (A. biplicata) start to disappear. Shell disappearance caused by animal-induced fragmentation affect all size groups; but we aren't able to evaluate its real impact on shell degradation since animal activities were largely restricted by plastic boxes. Under natural conditions, various animals largely enhance shell disappearance (for overview, see Cadée 2016).

All investigated biotopes have a specific taphonomic signature. While there are large differences among taphonomic signatures of wet and acidic sites (alder alluvial, peat-bog pine and planted spruce forests), differences among 10

more moderate sites (especially between oak-hornbeam and scree forests) are rather small. Taphonomic signatures are created by combined effect of moistness and acidity of particular habitat, but other influences (e.g. humic acids, animal-related breakage or fungal infestation) are also very important. None of observed shell alteration types was site-exclusive: all of them were recorded in all six habitats. But, some of them were rather specific to certain habitat, e.g. fungal infestation (Streptomyces tufts) in beech wood, empty periostraca in peat-bog pine forest, and fading in alder alluvial forest. Detrimental effects on shells have mainly been attributed to low soil/leaf litter pH and high soil moisture (e.g. Evans 1972, de Winter & Gittenberger 1998, Cadée 1999; Müller et al. 2005, Pearce 2008, Ström et al. 2009, Cernohorsky et al. 2010). We hypothesize that soil moisture is a more important factor than soil pH: soil moisture is a mediator of the effect of soil pH, i.e. in dryer sites the effect of pH would be weaker, since the shells are in contact with the acidic soil solution for shorter periods.

Scanning Electron Microscopy revealed that all model species possess the same type of calcareous microstructure: crossed-lamellar structure (for precise description, see work of Dauphin & Denis 2000 and Suzuki et al. 2011). However, large differences between species were observed. Shell wall thickness varies between 14 and 171 μm, number of first order layers varies between one and seven (Říhová 2018). Some of observed species (e.g. X. obvia or V. pulchella) have one-layered periostracum; periostracum of other species is two-layered. Some specimens of C. aspera and N. hammonis have three-layered periostracum. The largest differences were found in the relative thickness of the periostracum: species with high incidence of windows belong to species with the thickest periostracum observed. Their periostracum is also more frequently multi-layered. Species with one-layered periostracum inhabit dry and highly calcareous sites while species with thick and multi-layered periostracum are acidotolerant. Relatively thick and multi-layered periostracum protects anorganic layers against dissolutions. Species with thick periostracum, inhabiting acid habitats, usually have thin ostracal layers (see Table 7 in Říhová 2018) and their ostracum is generally one- or two-layered. It looks like those species “invest” more into construction of durable periostracum than into crystalization of complex calcareous layers which are threaten with dissolution. Extraordinary course of degradation is side-effect of it.

Conclusion Seven basic types of shell alteration were observed in Central European forests. Shell degradation pattern differed among species as well as among biotopes. The most important factor was the species identity. In contrary to large shells degrading slowly, almost all specimens of small species disappeared within three years. Two basic degradation patterns dependent on shell size were observed. The degradation of large species starts with periostracum disruption and peeling, followed by ostracal dissolution. Small shells retain periostracum while losing inorganic layers of the shell; and in extreme cases, only empty periostracum remains. The shell disappearance rates were biotope-specific: wet and acid biotopes had detrimental effect on shell condition as well as on persistence. Soil and leaf litter pH and soil moisture were the most important factors affecting shell persistence or disappearance; nonetheless, other influences were important for creation of site-specific taphonomic signature. We examined periostraca and ostraca of 36 species coming from ten families. The relative periostracum thickness range from 1.4% (in X. obvia, living on dry steppes) to 26% in acidotolerant land snail Zoogenetes harpa. Also the absolute thickness of shell wall varies largely, between 9–171 μm. Periostraca of majority species examined are two-layered. Only some species (usually strongly calciphilous or xerophilous species) possess one-layered periostracum. Several specimens with three-layered periostraca were recorded. Periostracum reaches less than 5% of complete shell wall thickness in two thirds of species investigated. There are also differences in ostracum architecture. Shell wall consists from one to six calcareous layers (1st order lamellae) with the maximum numbers in door snails. The majority of species has two- or four-layered ostracum. We agree with Cernohorsky et al. (2010) and Coppolino (2010) that empty shells can be used in faunistic studies to make a more complete species list. Their use in ecological and population biology analyses is more problematic: the nature and the rate of shell degradation is influenced by number of factors, comprising characteristics of the environment (which are highly local and site-specific in their action), interaction with local biota and characteristics of the shell itself. In any case, empty shells could provide valuable information and must not be overlooked.

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Müller J., Strätz Ch. et Hothorn T. 2005: Habitat factors for land snails in European beech forests with a special focus on coarse woody debris. European Journal of Forest Research 124: 233– 242.

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Pearce T.A. 2008: When a snail dies in the forest, how long will the shell persist? Effect of dissolution and micro-bioerosion. American Malacological Bulletin 26(1/2): 111–117.

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Říhová D., Janovský Z. et Koukol O. 2014: Fungal communities colonising empty Cepaea hortensis shells differ according to litter type. Fungal Ecology 8: 66–71.

Říhová D., Janovský Z., Horsák M. et Juřičková L. 2018: Shell decomposition rates in relation to shell size and habitat conditions in contrasting types of Central European forests. Journal of Molluscan Studies 84(1): 54–61.

Říhová D. 2018: Vliv morfometrických a mikrostrukturálních charakteristik na rozklad ulit plžů v lesních ekosystémech. Disertační práce, Přírodovědecká fakulta UK.

Říhová D. & Juřičková L. submitted: Degradation characteristics of empty land snail shells in Central European temperate forests. Folia Malacologica

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Curriculum vitae Name: Dagmar Říhová Date of Birth: May 14th, 1985 (Most, Czech Republic) Address: Petra Rezka 14 140 00, Praha 4 – Nusle Czech Republic Nationality: Czech Marital Status: Single Telephone Number: + 420 606 432 185 E-mail: [email protected]

Education: 2009–present PhD. study in study programme Zoology (Malacozoology), Faculty of Science, Charles University in Prague, subject of the dissertation thesis: The influence of morphological and microstructural characteristics to land snail degradation in forest environment 2007–2009 Master degree in study programme Biology, Faculty of Science, Charles University in Prague (master thesis Land snail shell degradation in forest environment) 2004–2007 Bachelor degree in study programme Biology, Faculty of Science, Charles University in Prague (bachelor thesis The impact of different vegetation conditions to the degradation of land snail shells in woodlands)

Employment 2011–present assistant professor on The Dept. of Biology and Environmental Sciences, Faculty of Education, Charles University in Prague; specialization in Protistology and Invertebrate Zoology 2013 and 2015 cooperation with Labrys o.p.s., determination of landsnail from archaeological samples 2009–2012 work for The Entomological Library (Faculty of Science, Charles University in Prague) 2009 extraction of oribatid mites from leaf litter samples (project GAAV No. KJB601110718 „Effect of oribatid mites (Acari: Oribatida) on spatial dispersion of saprotrophic fungi and competition within the fungal community: Case study on pine litter“) 2009 extraction of molluscs from soil and leaf litter samples for The Silva Tarouca Research Institute for Landscape and Ornamental Gardening

Other research activities 2013 the head of the FRVŠ project No. 701-202 „The innovation of Specialized Invertebrate Zoology“ 2013 the malacozoological research of the Bořeň Hill 2011–2014 the co-researcher of the GAČR project No. 42-201 898 „The role of generalist pollinators in agricultural landscapes – Implications for plant population dynamics“ 2010–2012 the co-researcher of the GAUK project No. 43-251 108 „The influence of herbivory on the Succisa pratensis population dynamics“ 2009–2011 the head of the GAUK project No. 43-259 101 „The influence of morphological and microstructural characteristics to land snail degradation in forest environment” 2008 the malacozoological research of Hostivice ponds

Pedagogical activities 2011–present pedagogic activities in the Faculty of Education, Charles University in Prague:

Biology of Unicellular Eukaryotes (Biologie jednobuněčných a příbuzných organismů) Invertebrate Zoology (Zoologie bezobratlých) – practical course Human and Animal Physiology (Fyziologie živočichů a člověka) – practical course

Field Studies I–III (Terénní práce I–III) Field Studies (Terénní práce pro NMgr. obory)

Specialized Invertebrate Zoology (Speciální zoologie bezobratlých) Entomology (Entomologie) Pedobiology (Půdní biologie) Training Course in Hydrobiology (Hydrobiologické praktikum)

Pedagogical Praxis II (Souvislá pedagogická praxe II) Teaching Practice in Leisure Centres (Pedagogická praxe ve volnočasových zařízeních) 2009–present field excursion in Faculty of Science, Charles University in Prague (Field Course in Zoology; Invertebrate zoology – practical course)

Other activities - organization of the biological club for high school students (since 2007) - collaboration in the organization of summer biological camp Arachne for high school students (since 2008) - the member in the editorial board of Malacologica Bohemoslovaca (2010– 2017) - partnership in the popularization projects „Otevřená věda“ and „Přírodovědci.cz“ (since 2011)

List of publications (*included in PhD. thesis) Říhová D. & Juračka P.J. (2010): Stories from the Scanning Microscope III. How Does Microstructure of the Molluscan Shell Look Like. Živa 3: 121. (in Czech)

Říhová D., Peltanová A. & Juřičková L. (2011): Is the Dune Snail Cernuella neglecta (Draparnaud, 1805) spreading in the Czech Republic? Malacologica Bohemoslovaca 10: 45–47. (in Czech)

Říhová D. & Juřičková L. (2011): The Girdled Snail Hygromia cinctella (Draparnaud, 1801) new to the Czech Republic. Malacologica Bohemoslovaca 10: 35–37.

*Koukol O. & Říhová D. (2013): Pentaster cepaeophilus gen. et sp. nov. described from litter of alder alluvial forest. Nova Hedwigia 96(3–4): 495–500.

*Říhová D., Janovský Z. et Koukol O. (2014): Fungal communities colonising empty Cepaea hortensis shells differ according to litter type. Fungal Ecology 8: 66–71.

Říhová D. (2015): The Dissection of the Spanish Slug (Arion vulgaris). Biologie Chemie Zeměpis 24(3): 111–118. (in Czech)

Gruntová Z. & Říhová D. (2015): Hidden Life in the Moss: a Microscopic Lesson. Biologie Chemie Zeměpis 24(5): 219–224. (in Czech)

Čejka T., Čačaný J., Horsák M., Juřičková L., Buďová J., Duda M., Holubová A., Horsáková V., Jansová A., Kocurková A., Korábek O., Maňas M., Říhová D. et Šizling A.L. (2015): Freshwater molluscs of water bodies with a high conservation value in the Danubian lowland (SW Slovakia). Malacologica Bohemoslovaca 14: 5–16. (in Czech)

Podroužková Š., Juřičková L., Hronová H., Beran L., Říhová D. et Ložek V. (2015): Molluscs of the upper and middle Kačák brook valley. Malacologica Bohemoslovaca 14: 74–90. (in Czech)

Janovský Z., Janovská M., Weiser M., Horčičková E., Říhová D. et Münzbergová Z. (2016): Surrounding vegetation mediates frequency of plant–herbivore interactions in leaf-feeders but not in other herbivore groups. Basic and Applied Ecology 17: 352– 359.

Říhová D. (2017): Palynologist, quickly & easily. Biologie Chemie Zeměpis 26(2): 17–25. (in Czech)

*Říhová D., Janovský Z., Horsák M. et Juřičková L. (2018): Shell decomposition rates in relation to shell size and habitat conditions in contrasting types of Central European forests. Journal of Molluscan Studies 84: 54–61.

Kebert T. & Říhová D. (2018): Molluscs in Ecological Context. Biologie Chemie Zeměpis 27(1): 16 –22. (in Czech)

Říhová D. & Šrámková J. (2018): What do slugs eat? Food preferences of land snails and how to investigate them. Biologie Chemie Zeměpis, in press. (in Czech)

Conference Presentations

Říhová D., Janovský Z. & Juřičková L. (2009): Land snail shell degradation in forest environment. Molluscan Forum London 2009; oral presentation.

Janovský Z., Říhová D., Vosolsobě S., Ponert J., Pavlíková A. & Mikát M. (2010): Aktivita opylovačů čertkusu lučního jako funkce vlastností jednotlivých rostlin a povětrnostních podmínek. Sborník abstraktů z konference Zoologické dny Praha 2010, eds. Bryja J. & Zasadil P., Praha 2010, 277 str.; oral presentation.

Vosolsobě S., Janovský Z., Mikát M., Říhová D., Pavlíková A. & Ponert J. (2010): Efektivita přenosu pylu u opylovačů čertkusu lučního. Sborník abstraktů z konference Zoologické dny Praha 2010, eds. Bryja J. & Zasadil P., Praha 2010, 277 str.; poster. This poster was awarded by the price in student contest.

Říhová D., Janovský Z. & Juřičková L. (2010): Land snail shell degradation in temperate forest. Tropical Natural History, Supplementum 3: 265; 17th World Congress of Malacology Phuket, Thailand; poster.

Pavlíková A., Říhová D., Janovský Z., Mikát M., Ponert J. & Vosolsobě S. (2011): Protichůdné selekční tlaky opylovačů a granivorů. Sborník abstraktů z konference Zoologické dny Brno 2011, eds. Bryja J., Řehák Z. & Zukal J., Brno 2011, 282 str.; oral presentation.

Říhová D. & Juřičková L. (2011): Jednonohá cestovatelka dobývá Evropu: tenkostěnka kýlnatá (Hygromia cinctella) poprvé v České republice. Sborník abstraktů z konference Zoologické dny Brno 2011, eds. Bryja J., Řehák Z. & Zukal J., Brno 2011, 282 str.; poster.

Szalontayová V., Říhová D., Petrusek A. & Juřičková L. (2011): Genetical and morphological diversity in genus Cochlodina (Gastropoda: Clausiliidae). 6th Congress of the European Malacological Societies, Vitoria-Gasteiz, Spain. This poster was awarded by the price in student contest.

Říhová D., Janovský Z. & Juřičková L. (2011): Land snail shell degradation: its causes and manifestation). 6th Congress of the European Malacological Societies, Vitoria-Gasteiz, Spain; oral presentation.

Říhová D., Janovský Z. & Koukol O. (2013): When malacology meets mycology: microfungal colonisation of empty Cepaea shells. Açoreana Suplemento 8: 355. 18th World Congress of Malacology, Ponta Delgada, Azores, Portugal; poster.

Říhová D., Holubová A. & Juřičková L. (2017): Kabát do každého deště – předběžná zpráva o stavu periostraka vybraných suchozemských plžů. Sborník abstraktů z konference Zoologické dny Brno 2017, eds. Bryja J., Horsák M., Horsáková V., Řehák Z. & Zukal J., Brno 2017, 254 str.; oral presentation.

Říhová D., Holubová A. & Juřičková L. (2017): Coat for every occasion: periostracum of selected land snails – a preliminary report. Book of abstract of 8th Euromal, Kraków, Poland; p. 87; oral presentation. This talk was awarded by 2nd price in student contest.

Říhová D. & Juřičková L. (2017): How well do you know your snails? Book of abstract of 8th Euromal, Kraków, Poland; p. 108; poster.