Matjaž Gregorič

Matjaž Gregorič
Research Centre of the Slovenian Academy of Sciences and Arts | ZRC SAZU · Jovan Hadži Institute of Biology

PhD

About

62
Publications
19,543
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
643
Citations
Additional affiliations
January 2015 - December 2015
University of Akron
Position
  • PostDoc Position
August 2011 - December 2011
University of Puerto Rico at Rio Piedras
Position
  • University of Puerto Rico
October 2009 - November 2009
University of Akron
Education
October 2008 - September 2013
University of Ljubljana
Field of study
  • Biology
October 2000 - October 2008
University of Ljubljana
Field of study
  • Biology

Publications

Publications (62)
Article
Full-text available
Natural silks crafted by spiders comprise some of the most versatile materials known. Artificial silks–based on the sequences of their natural brethren–replicate some desirable biophysical properties and are increasingly utilized in commercial and medical applications today. To characterize the repertoire of protein sequences giving silks their bio...
Article
Full-text available
The concept of environmental DNA (eDNA) utilizes nucleic acids of organisms directly from the environment. Recent breakthrough studies have successfully detected a wide spectrum of prokaryotic and eukaryotic eDNA from a variety of environments, ranging from ancient to modern, and from terrestrial to aquatic. With their diversity and ubiquity in nat...
Article
Full-text available
Examining the role of color in mate choice without testing what colors the study animal is capable of seeing can lead to ill-posed hypotheses and erroneous conclusions. Here, we test the seemingly reasonable assumption that the sexually dimorphic red coloration of the male jumping spider Saitis barbipes is distinguishable, by females, from adjacent...
Article
Full-text available
Adult body size, development time, and growth rates are components of organismal life histories, which crucially influence fitness and are subject to trade-offs. If selection is sex-specific, male and female developments can eventually lead to different optimal sizes. This can be achieved through developmental plasticity and sex-specific developmen...
Article
Subterranean environments of Iran are severely understudied. Here, we advance the knowledge of Iranian cave biodiversity by following three goals: (i) to investigate Iranian caves for troglobiotic beetles; (ii) to understand the phylogenetic relationships and estimate the timing of Iranian cave colonization by Duvalius Delarouzée, 1859; and (iii) t...
Article
Full-text available
Reconstructing biogeographic history is challenging when dispersal biology of studied species is poorly understood, and they have undergone a complex geological past. Here, we reconstruct the origin and subsequent dispersal of coin spiders (Nephilidae: Herennia Thorell), a clade of 14 species inhabiting tropical Asia and Australasia. Specifically,...
Article
Full-text available
The current COVID-19 pandemic caught the decision makers in many countries sub-optimally prepared to respond. To better cope with similar situations in the future, it is vital to understand the major predictors of health-beneficial behavior and adherence to imposed mitigation measures and guidelines. To tailor the promotion of government-imposed me...
Article
The spider major ampullate (MA) silk exhibits high tensile strength and extensibility and is typically a blend of MaSp1 and MaSp2 proteins with the latter comprising glycine–proline–glycine–glycine-X repeating motifs that promote extensibility and supercontraction. The MA silk from Darwin's bark spider ( Caerostris darwini ) is estimated to be two...
Article
Full-text available
Theory suggests that consistent individual variation in behavior relates to fitness, but few studies have empirically examined the role of personalities in mate choice, male-male competition and reproductive success. We observed the Mediterranean black widow, Latrodectus tredecimguttatus, in the individual and mating context, to test how body size...
Preprint
Objective: To investigate the perception and adherence to mitigation measures during the first wave of the COVID-19 epidemic in Slovenia by examining their trends across several sociodemographic categories and personality dimensions. Methods: Descriptive and correlative analyses were used to examine which sociodemographic and personality factors we...
Preprint
Full-text available
The concept of environmental DNA (eDNA) utilizes nucleic acids of organisms directly from the environment. Recent breakthrough studies have successfully detected a wide spectrum of prokaryotic and eukaryotic eDNA from a variety of environments, ranging from ancient to modern, and from terrestrial to aquatic. These numerous sources promise to establ...
Article
Vicariance and dispersal events, combined with intricate global climatic history, have left an imprint on the spatiotemporal distribution and diversity of many organisms. Anelosimus cobweb spiders (Theridiidae), are organisms ranging in behavior from solitary to highly social,l with a cosmopolitan distribution in temperate- to-tropical areas. Their...
Article
Full-text available
Darwin's bark spider (Caerostris darwini) produces giant orb webs from dragline silk that can be twice as tough as other silks, making it the toughest biological material. This extreme toughness comes from increased extensibility relative to other draglines. We show C. darwini dragline-producing major ampullate (MA) glands highly express a novel si...
Chapter
Slovenia is a biodiversity hotspot due to its location at the junction of four biogeographical regions with different ecological conditions. Because of this, 37.87% of Slovenia’s area is currently classified as Natura 2000 sites, the highest share among the 28 EU countries. Slovenian flora comprises 3472 vascular taxa and is rich in endemic species...
Chapter
Full-text available
Spiders with around 48,000 recorded species are major terrestrial predators and thus crucially important for ecosystem functioning. They are widely used as research models and for biodiversity displays and sometimes also kept as pets. Nevertheless, we are not aware of any legal ethical rules bound to spider welfare during rearing or research. To se...
Article
Full-text available
Instances of sexual size dimorphism (SSD) provide the context for rigorous tests of biological rules of size evolution, such as Cope's rule (phyletic size increase), Rensch's rule (allometric patterns of male and female size), as well as male and female body size optima. In certain spider groups, such as the golden orbweavers (Nephilidae), extreme...
Article
Full-text available
Selection pressures leading to extreme, female-biased sexual size dimorphism (SSD) in spiders continue to be debated. It has been proposed that males of sexually size dimorphic spiders could be small because gravity constrains adult agility (locomotor abilities). Accordingly, small males should achieve higher vertical climbing speeds and should be...
Preprint
Full-text available
Instances of sexual size dimorphism (SSD) provide the context for rigorous tests of biological rules of size evolution, such as Copes Rule (phyletic size increase), Renschs Rule (allometric patterns of male and female size), as well as male and female body size optima. In certain spider groups, such as the golden orbweavers (Nephilidae), extreme fe...
Article
Full-text available
Though not uncommon in other animals, heterospecific mating is rarely reported in arachnids. We investigated sexual interactions among four closely related and syntopical African golden orbweb spiders, Nephila inaurata, N. fenestrata, N. komaci, and N. senegalensis. In two South African localities, female webs were often inhabited by heterospecific...
Article
Full-text available
Leaf masquerade-an animal resembling leaves that are inedible for predators or innocuous for prey-is well known in insects but less so in arachnids. We report a case of a striking morphological and behavioral adaptation that can be labeled as leaf masquerade in an undescribed spider species (Poltys C.L. Koch, 1843, Araneidae) from southwest China....
Article
Full-text available
The use of unique DNA sequences as a method for taxonomic identification is no longer fundamentally controversial, even though debate continues on the best markers, methods, and technology to use. Although both existing databanks such as GenBank and BOLD, as well as reference taxonomies, are imperfect, in best case scenarios ''barcodes'' (whether s...
Data
The results of the barcode matching test.
Data
Original sequences this project submitted to BOLD and GenBank (only those on GenBank are also publically available on BOLD, for all others, see http://ezlab.zrc-sazu.si/dna/). Legend: MNH, SI = National Museum of Natural History, Smithsonian Institution; EZ LAB = Evolutionary Zoology Lab, ZRC SAZU; NMBE = Naturhistorisches Museum der Burgergemeinde...
Data
The downloaded sequences used in the species comparison.
Article
Full-text available
Several clades of spiders whose females evolved giant sizes are known for extreme sexual behaviors such as sexual cannibalism, opportunistic mating, mate-binding, genital mutilation, plugging, and emasculation. However, these behaviors have only been tested in a handful of size dimorphic spiders. Here, we bring another lineage into the picture by r...
Preprint
Full-text available
The use of unique DNA sequences as a method for taxonomic identification is no longer fundamentally controversial, even though debate continues on the best markers, methods, and technology to use. Although both existing databanks such as GenBank and BOLD, as well as reference taxonomies, are imperfect, in best case scenarios “barcodes” (whether sin...
Preprint
Full-text available
The use of unique DNA sequences as a method for taxonomic identification is no longer fundamentally controversial, even though debate continues on the best markers, methods, and technology to use. Although both existing databanks such as GenBank and BOLD, as well as reference taxonomies, are imperfect, in best case scenarios “barcodes” (whether sin...
Article
Full-text available
Bark spiders (genus Caerostris Thorell 1868) are important models in biomaterial research due to the remarkable biomechanical properties of the silk of C. darwini Kuntner & Agnarsson 2010 and its gigantic web. They also exhibit female gigantism and are promising candidates for coevolutionary research on sexual dimorphism. However, Caerostris spider...
Article
Full-text available
Orb-weaving spiders are good objects for evolutionary research, but phylogenetic relationships among and within orb-weaving lineages are poorly understood. Here we present the first species-level molecular phylogeny that includes the enigmatic orb weavers ‘Zygiellidae’ and Caerostris. Zygiellidae is interesting for the evolution of the sector web,...
Article
Full-text available
Body size affects almost all aspects of animals' resource use, and its scaling syntheses are well established in most biological fields. In contrast, how behavioral variation scales with body size is understudied. Understanding how body size influences behavior is important as behavior responds more readily to natural selection than many other trai...
Data
Corrected TaxPub XML of the original publication
Data
Corrected occurrences as Darwin Core Archive
Article
Full-text available
The sentence with corrected counts should now read: "We here report on the faunistic part of this project, which resulted in 320 species ( 224 in Slovenia, 142 in Switzerland) for which identification was reasonably established".
Article
Full-text available
We investigated the mating biology of the previously unstudied central European spider Leviellus thorelli (Ausserer 1871) by staging laboratory mating trials using males and females of varying mating histories. Our aim was to seek common themes in sexual behaviors of the sexually size-monomorphic ''zygiellid'' spiders with their putatively close re...
Article
Full-text available
Given the limited success of past and current conservation efforts, an alternative approach is to preserve tissues and genomes of targeted organisms in cryobanks to make them accessible for future generations. Our pilot preservation project aimed to obtain, expertly identify, and permanently preserve a quarter of the known spider species diversity...
Article
Full-text available
Evolutionary convergence of phenotypic traits provides evidence for their functional success. The origin of the orb web was a critical event in the diversification of spiders that facilitated a spectacular radiation of approximately 12 000 species and promoted the evolution of novel web types. How the orb web evolved from ancestral web types, and h...
Article
Full-text available
The biogenetic law posits that the ontogeny of an organism recapitulates the pattern of evolutionary changes. Morphological evidence has offered some support for, but also considerable evidence against, the hypothesis. However, biogenetic law in behavior remains underexplored. As physical manifestation of behavior, spider webs offer an interesting...
Data
Full-text available
Sexual cannibalism particularly before mating is costly for the male victim but also for the female aggressor if she risks remaining unmated. The aggressive spillover hypothesis explains the persistence of this behavior as a maladaptive side effect of positive selection on aggressiveness in a foraging context. The hypothesis predicts that the occur...
Article
Full-text available
Nephila are known for the greatest degrees of sexual size dimorphism among orb weaving spiders (Araneoidea) and thus among terrestrial animals. However, a meaningful quantification of the dimorphism is lacking and the proximate developmental mechanisms of female gigantism are poorly understood, being attributed solely to female delayed maturation....
Article
Full-text available
Males usually produce mating plugs to reduce sperm competition. However, females can conceivably also produce mating plugs in order to prevent unwanted, superfluous and energetically costly matings. In spiders-appropriate models for testing plugging biology hypotheses-mating plugs may consist of male genital parts and/or of amorphous covers consist...
Data
Nephila pilipes mating: male approach followed by unsuccessful insertion attempt. (MPG)
Data
Nephila pilipes mating: male successful insertion. (MPG)
Data
Nephila pilipes mating: male performing mate-binding in-between insertion attempts. (MPG)
Article
Full-text available
Although the diversity of spider orb web architectures is impressive, few lineages have evolved orb webs larger than 1m in diameter. Until recently, such web gigantism was reported only in a few nephilids and araneids. However, new studies on bark spiders (Caerostris) of Madagascar report a unique case of web gigantism: Darwin's bark spider (C. dar...
Data
C. darwini using bridging silk. Note the sail-like terminus of the bridging silk. (MPG)
Data
C. darwini using bridging silk. Note the sail-like terminus of the bridging silk. (MPG)
Article
Full-text available
Interspecific coevolution is well described, but we know significantly less about how multiple traits coevolve within a species, particularly between behavioral traits and biomechanical properties of animals' "extended phenotypes". In orb weaving spiders, coevolution of spider behavior with ecological and physical traits of their webs is expected....
Article
Full-text available
Sexual cannibalism particularly before mating is costly for the male victim but also for the female aggressor if she risks remaining unmated. The aggressive spillover hypothesis explains the persistence of this behavior as a maladaptive side effect of positive selection on aggressiveness in a foraging context. The hypothesis predicts that the occur...
Article
Genital amputation, that is, genital damage or loss, seems maladaptive because it renders the amputee functionally sterile, but is nevertheless common in sexually dimorphic spiders. In these species, male genital amputation correlates with plugging of female genitals and with sexual cannibalism. Genital amputation in male spiders may be partial or...
Article
Full-text available
The architecture of vertical aerial orb webs may be affected by spider size and gravity or by the available web space, in addition to phylogenetic and/or developmental factors. Vertical orb web asymmetry measured by hub displacement has been shown to increase in bigger and heavier spiders; however, previous studies have mostly focused on adult and...
Article
Full-text available
The species classically grouped in the genus Zygiella F.O. Pickard-Cambridge 1902 are thought to all possess a characteristic orb web feature — a spiral-free sector in the upper part of the orb. Zygiella s.l. has recently been split into four genera, Zygiella s.s., Leviellus Wunderlich 2004, Parazygiella Wunderlich 2004 and Stroemiellus Wunderlich...
Article
Spider web research bridges ethology, ecology, functional morphology, material science, development, genetics, and evolution. Recent work proposes the aerial orb web as a one-time key evolutionary innovation that has freed spider-web architecture from substrate constraints. However, the orb has repeatedly been modified or lost within araneoid spide...
Article
Full-text available
Plugging of female genitals via male sexual mutilation is a common sexual repertoire in some nephilid spiders (Herennia, Nephila, Nephilengys), but the behavioral pathways leading to emasculation are poorly understood. Recent work suggests that copulating Herennia males damage their reproductive organs during copulation and then voluntarily, and st...
Article
Full-text available
The classical Karst (Kras in Slovenian) is a limestone karst plateau of south-western Slovenia and northeastern Italy surrounded by flysch or alluvial areas. We explored surface spider species richness in the Karst by conducting a season-long quantitative inventory of the epigean fauna. By examining three localities, each with three succession-stag...

Network

Cited By

Projects

Projects (3)
Project
Females and males commonly differ in the expression of traits. The evolution of sexual dimorphism requires sex-specific selection and at least partly independent genetic variation between the sexes. However, females and males share an almost identical genome that constrains the sexes to respond independently to the selection and may result in a stage when one or both sexes express traits outside their optima. Quantitative genetics provides tools to predict the extent to which the evolution of sexual dimorphism is genetically constrained between sexes by assessing the cross-sex genetic correlation. The cross‐sex genetic correlation can be estimated as rmf =COVAmf∕sqrt(VAf ∗VAm), where COVAmf is the additive genetic covariance between the sexes, and VAm and VAf are additive genetic variances of males and females, respectively. When is close to unity, the sexes are assumed to have a nearly identical genetic architecture for the trait and evolution of sexual dimorphism should be constrained; close to zero values of rmf indicate complete independence in the genetic architecture of the trait between males and females and thus sex independent evolution. A cross‐sex genetic correlation between zero and one suggests that some of the genes acting on the shared trait already differ between males and females and indicates a further possibility for the evolution of sexual dimorphism in the trait. In this project, we aim to assess genetic variances and cross‐sex genetic correlations of size in an extremely sexually-size dimorphic spider, Nephilinis cruentata. In these spiders, females are considerably larger than males, they weigh more than 70X more than males. Our preliminary analyses found rmf close to zero suggesting that females and males do not share genetic architecture for size, indicates a resolved intra-locus sexual conflict and potential for further sex independent evolution of size. The result reflects differences in the effects of sexual and natural selection on body size between the sexes. The amount of genetic variation is significantly lower in females compared to males implying that females have been under the stronger directional selection (for fecundity) compared to males that are more plastic.