Higher Taxa Research Articles

Does Clade Density Constrain Geographical Range Evolution?

The role of biotic interactions, such as interspecific competition, in driving geographical range evolution is still poorly understood. For instance, lineages distributed across regions with a large number of potential competitors might experience some level of geographical packing of their range limits, so that changes in their geographical distributions are hampered. Conversely, a large number of competitors could instead lead to accelerated rates of geographical range evolution, with lineages shifting their ranges to avoid competition. We recently introduced the concept of clade density (CD; the sum of the areas of overlap between a species and other members of its higher taxon, weighted by their phylogenetic distance) as a proxy of the potential for interspecific competition across the geographical distribution of a given species. In this study, we used a large dataset with 5936 terrestrial vertebrate species to test whether CD is significantly associated with variation in the rate of geographical range evolution using two alternative approaches. First, we tested if there is a significant relationship between CD and the geographical distance between sister species. In addition, we estimated tip rates of geographical range evolution and tested if they were consistently associated with variation in CD. We found no evidence for an effect of CD on geographical range evolution in either of the tested approaches, even after accounting for phylogenetic uncertainty. These results are inconsistent with equilibrial models of species diversification and suggest that interspecific competition might not play a pervasive role in geographical range evolution of terrestrial vertebrates.

Towards a Taxonomy Machine: A Training Set of 5.6 Million Arthropod Images

The taxonomic identification of organisms from images is an active research area within the machine learning community. Current algorithms are very effective for object recognition and discrimination, but they require extensive training datasets to generate reliable assignments. This study releases 5.6 million images with representatives from 10 arthropod classes and 26 insect orders. All images were taken using a Keyence VHX-7000 Digital Microscope system with an automatic stage to permit high-resolution (4K) microphotography. Providing phenotypic data for 324,000 species derived from 48 countries, this release represents, by far, the largest dataset of standardized arthropod images. As such, this dataset is well suited for testing the efficacy of machine learning algorithms for identifying specimens into higher taxonomic categories.

Molecular phylogenetic relationships among lineages in the genus Carabus (Coleoptera: Carabidae) and radiation of the subgenus Apotomopterus

Abstract The genus Carabus (Coleoptera: Carabidae: Carabinae) is a group of predacious ground beetles found throughout Holarctic temperate zones. The diversification of this group is attributed not only to allopatric speciation but also to diversification in life-history traits and morphological traits that are involved in ecological adaptation and reproductive isolation. Precise phylogenetic reconstruction of Carabus is important to understanding the factors associated with species’ divergence in relation to such character divergence. Here, we analyse the phylogeny of Carabus among higher taxonomic groups and among species of the subgenus Apotomopterus, a hyper-diverse group endemic to East Asia. We used genome-wide sequence data from ultraconserved elements for phylogenetic reconstruction via maximum-likelihood and species-tree reconstruction methods. With regard to the relationships among higher taxonomic groups, the obtained phylogenetic trees resolved two structures with previously unresolved divergence. The subgenus Apotomopterus contained three lineages, i.e. the Vitalisi, Prodigus, and Sauteri groups. It showed diversification of the spinula, a sclerotized male genital structure, and variation in the female elytral notch (preapical emargination). These morphological traits may be involved in copulatory behaviour and potentially affect reproductive isolation, and their character state divergence may have facilitated species divergence of Apotomopterus.

Metazoan parasite fauna of grey mullet (Mugilidae) from the coastal waters of Vietnam

A total of 201 fishes of the family Mugilidae caught off central Vietnam (Nha Trang Bay) were examined for parasites. Eight species of Mugilidae were identified based on cytb and 16S rRNA sequences. Protozoa were not revealed. The metazoan parasites belong to six higher taxa. Myxozoa Grassé, 1970 is represented by six genera, three of which were first found in grey mullets off Vietnam. The specimens of Monogenea Van Beneden, 1858 belong to two genera: Ligophorus Euzet et Suriano, 1977 and Metamicrocotyla Yamaguti, 1953. Twelve species of the former were recorded for the first time both in the coastal waters of Vietnam and in the East Sea. Trematoda Rudolphi, 1808 is represented by the members of the four families, of which only three species, Haplosplanchnus pachysoma (Eysenhardt, 1892), Pseudohaploporus planilizum Atopkin, Besprozvannykh, Ha, Nguyen, Nguyen & Chalenko, 2019 and Spiritestis arabii Nagaty, 1948, were identified. The latter was first recorded in the East Sea. Acanthocephala Rudolphi, 1808 specimens belong to the species Neoechinorhynchus dimorphospinus Amin & Sey, 1996. Crustacea Brünnich, 1772 are represented by five families, of which only the copepod Lernanthropsis mugilii (Shishido, 1898) and the isopod Nerocila orbignyi (Guérin, 1832) were identified. Hirudinea Savigny, 1822 were not determined to genus and species level. A total of 25 species of parasites were found in the Mugilidae fishes examined in Nha Trang Bay. In general, 96 species of parasites are currently documented in these fishes in the East Sea, 55 of which occur off Vietnam. As a result of this study, carried out off central Vietnam, 16 parasite species were recorded in grey mullet for the first time in Vietnamese coastal waters and 15 for the first time in the East Sea. Thus, extending the geographical range of the studies may result in new records of parasites in these fishes.

Multidecadal changes in coastal benthic species composition and ecosystem functioning occur independently of temperature-driven community shifts.

Rising global temperatures are often identified as the key driver impacting ecosystems and the services they provide by affecting biodiversity structure and function. A disproportionate amount of our understanding of biodiversity and function is from short-term experimental studies and static values of biodiversity indices, lacking the ability to monitor long-term trends and capture community dynamics. Here, we analyse a biennial dataset spanning 32 years of macroinvertebrate benthic communities and their functional response to increasing temperatures. We monitored changes in species' thermal affinities to examine warming-related shifts by selecting their mid-point global temperature distribution range and linking them to species' traits. We employed a novel weighted metric using Biological Trait Analysis (BTA) to gain better insights into the ecological potential of each species by incorporating species abundance and body size and selecting a subset of traits that represent five ecosystem functions: bioturbation activity, sediment stability, nutrient recycling and higher and lower trophic production. Using biodiversity indices (richness, Simpson's diversity and vulnerability) and functional indices (richness, Rao's Q and redundancy), the community structure showed no significant change over time with a narrow range of variation. However, we show shifts in species composition with warming and increases in the abundance of individuals, which altered ecosystem functioning positively and/or non-linearly. Yet, when higher taxonomic groupings than species were excluded from the analysis, there was only a weak increase in the measured change in community-weighted average thermal affinities, suggesting changes in ecosystem functions over time occur independently of temperature increase-related shifts in community composition. Other environmental factors driving species composition and abundance may be more important in these subtidal macrobenthic communities. This challenges the prevailing emphasis on temperature as the primary driver of ecological response to climate change and emphasises the necessity for a comprehensive understanding of the temporal dynamics of complex systems.

Bacterial Pangenome: A Review on the Current Strategies, Tools and Applications

The genomic research has grown by the advancement of sequencing technologies, which aim to capture the "totality" of life diversity by progressing from single strain to species or even higher taxa. Out of this scientific progress and inquisitiveness, the term "pangenome" was created. The goal of a pangenome is to represent all of a species genetic variation. It divides the genome into core, accessory and unique genes. Since the introduction of pangenomics, many software programs have been actively used for pangenome analysis. This review focuses on providing a snapshot of useful tools with their use, execution and computational details. In addition to tools for pangenome, the components, approaches, mechanism of variation, applications and challenges associated with pangenome analysis are also discussed in this article. Here, we have also discussed the increasing trend of bacterial pangenome studies with few studies and their significant findings. It has been proved that pangenomics is useful for understanding the clade of bacteria that helps in developing strategies for various application based on biological similarities and differences.

Nomenclatural stability and the longevity of helminth species names

Although most Latin binomial names of species are valid, many are eventually unaccepted when they are found to be synonyms of previously described species, or superseded by a new combination when the species they denote are moved to a different genus. What proportion of parasite species names become unaccepted over time, and how long does it take for incorrect names to become unaccepted? Here, we address these questions using a dataset comprising thousands of species names of parasitic helminths from four higher taxa (Acanthocephala, Nematoda, Cestoda, and Trematoda). Overall, among species names proposed in the past two-and-a-half centuries, nearly one-third have since been unaccepted, the most common reason being that they have been superseded by a new combination. A greater proportion of older names (proposed pre-1950) have since been unaccepted compared to names proposed more recently, however most taxonomic acts leading to species names being unaccepted (through either synonymy or reclassification) occurred in the past few decades. Overall, the average longevity of helminth species names that are currently unaccepted was 29 years; although many remained in use for over 100 years, about 50% of the total were invalidated within 20 years of first being proposed. The patterns observed were roughly the same for all four higher helminth taxa considered here. Our results provide a quantitative illustration of the self-correcting nature of parasite taxonomy, and can also help to calibrate future estimates of total parasite biodiversity.

Barcoding and mitochondrial phylogenetics of Porites corals.

Coral reefs are the most diverse ecosystem on the planet based on the abundance and diversity of phyla and higher taxa. However, it is still difficult to assess the diversity of lower taxa, especially at the species level. One tool for improving the identification of lower taxa are genetic markers that can distinguish cryptic species and assess species boundaries. Here, we present one such approach for an important and challenging group of reef-building corals. Porites corals are the main reef-builders of many coral reefs in the Indo-Pacific, owing to the massive growth forms of some species. The current number of valid Porites species is controversial, inflated with many synonymies, and often based on gross colony morphology although several morphospecies believed to be widespread and common can only be distinguished based on detailed microstructure analyses by taxonomic experts. Here, we test the suitability of multiple regions of mtDNA as genetic barcodes to identify suitable markers for species differentiation and unambiguous identification. Resulting sequencing data was further used for the first phylogenetic analysis of Guam's Porites species. We tested eight different mitochondrial markers and analyzed four in detail for 135 Porites specimens: mtDNA markers were amplified for 67 Porites specimens from Guam, representing 12 nominal Porites species, and combined with 69 mitochondrial genomes, mostly from Hawaii. The combination of all 4 markers distinguished 10 common and 7 uncommon Central-West Pacific Porites species. Most clades separate species along taxonomic boundaries, which is uncommon for Porites corals and testifies to the suitability of our multi-marker approach, and a combination of the two most promising barcodes distinguished 8/10 common species. These barcodes are thus suitable to distinguish virtually cryptic species in one of the most important and challenging coral genera. They offer a cheap, fast and reliable way to identify Porites species for species-level research, monitoring and conservation.

Both-strand gene coding in a plastome-like mitogenome of an enoplid nematode.

The phylum Nematoda remains very poorly sampled for mtDNA, with a strong bias toward parasitic, economically important or model species of the Chromadoria lineage. Most chromadorian mitogenomes share a specific order of genes encoded on one mtDNA strand. However, the few sequenced representatives of the Dorylaimia lineage exhibit a variable order of mtDNA genes encoded on both strands. While the ancestral arrangement of nematode mitogenome remains undefined, no evidence has been reported for Enoplia, the phylum's third early divergent major lineage. We describe the first mitogenome of an enoplian nematode, Campydora demonstrans, and contend that the complete 37-gene repertoire and both-strand gene encoding are ancestral states preserved in Enoplia and Dorylaimia versus the derived mitogenome arrangement in some Chromadoria. The C. demonstrans mitogenome is 17,018 bp in size and contains a noncoding perfect inverted repeat with 2013 bp-long arms, subdividing the mitogenome into two coding regions. This mtDNA arrangement is very rare among animals and instead resembles that of chloroplast genomes in land plants. Our report broadens mtDNA taxonomic sampling of the phylum Nematoda and adds support to the applicability of cox1 gene as a phylogenetic marker for establishing nematode relationships within higher taxa.

Towards a genomic resolution of the Phengaris alcon species complex

AbstractTaxonomic entities below the species level often pose difficulties for conservation practice, especially when they are ecologically distinct from the nominal species. Genomic tools provide the opportunity to study and potentially resolve such cryptic diversity. The Alcon blue butterfly Phengaris alcon species complex is such a cryptic example, comprising different ecotypes or even subspecies, one of them is the high elevation taxon P. rebeli from the European Alps. We sequenced a first reference genome for Phengaris alcon. Furthermore, we generated whole genome resequence data for individuals of three Swiss ecotypes, i.e., the low elevation P. alcon, the mid elevation and high elevation alpine P. rebeli and integrated genomic data from across Europe to study the relationship among these ecotypes. At a European scale, our results suggest that for the P. alcon complex, biogeography and the evolutionary context of diversification is more multifaceted than previously suggested, falling in the range of more recent ecological speciation. In Switzerland, the three ecotypes were genetically isolated with only limited current gene flow between them. Past gene flow, however, could have given rise to the mid elevation ecotype. Our findings emphasise that high elevation P. rebeli in the Alps should be treated as a distinct species. Our study highlights how the availability of reference genome assemblies allows to address so far open taxonomic questions in conservation research and that broadscale studies are needed to understand the biogeographic history of apparent diversification.

COMMUNITY STRUCTURE AND DIVERSITY OF BENTHIC MACROINVERTEBRATES IN ALAM KANDUNG WATERFALL TULUNGAGUNG REGENCY

This research aims to determine the profile of the community structure and diversity of benthic macroinvertebrates in Alam Kandung Waterfall. Sampling was carried out at six stations of ± 100 individuals or stations that use surber net and hand net. Data collection for each station includes the composition and density of each species which is used to calculate taxa richness, abundance, IVI (Important Value Index), and diversity index (H'). The results showed that 37 taxa from 11 classes were found and varied at each station. At the first station, the highest taxa were found with a total of 19 taxa, and the lowest taxa at the second station with 7 taxa. The highest abundance is known at the first station and the lowest at the sixth station. The IVI results show that the first and second stations are dominated by the type of Sulcospira testudinaria which is sensitive to pollutants, and the third station and fourth are dominated by Tarebia granifera and Vellidae. The fifth station was dominated by Corixidae, while Thiara scraba and Atyidae were found in all stations. The results of the diversity index show that the first and fourth are lightly polluted, the second station is moderately polluted and the rest are not polluted. It can be concluded that the quality of waterfalls in Alam Kandung is still in a good category, reflected by the diversity of taxa and the presence of riparian vegetation.

Dietary Bacillus cereus LS2 protects juvenile sea cucumber Apostichopus japonicus against Vibrio splendidus infection

This study aimed to investigate the effects of Bacillus cereus LS2 on the growth performance, innate immunity, intestinal microbiota, and disease resistance of sea cucumber Apostichopus japonicus. After feeding with LS2 for 30 days, results showed that dietary with LS2 had a significant improvement in the growth rate and immune parameters (including total coelomocytes counts, phagocytosis, respiratory burst, and immune-related enzymes) of juvenile sea cucumbers. Subsequently, transcriptome sequencing and qRT-PCR verification were performed to analyze the potential mechanism of LS2 diet and thus improve the immune response of A. japonicus. GO and KEGG pathway analysis indicated that LS2 can primarily activate the “Lectins” and “complement and coagulation cascades” pathways to modulate the innate immunity of the sea cucumbers. Furthermore, 16S rRNA sequencing was used to analyze the intestinal microbial composition of sea cucumbers after dietary with LS2. Results showed that Proteobacteria, Actinobacteria, Firmicutes, and Bacteroidetes were the most prevalent phyla in A. japonicus intestinal microbiota. The abundance of Actinobacteria (46.20%) and Bacteroidetes (12.80%) were significantly higher in the LS2 group, whereas the relative abundance of Proteobacteria (49.98%) and Firmicutes (14.97%) were higher in the control group. The LDA scores of Nocardiaceae and Rhodococcus were also the highest taxa after the dietary administration of LS2, indicating that Actinobacteria phylum played a pivotal role in the intestinal microbial function of A. japonicus. Overall, these results suggested that feeding with Bacillus LS2 may be beneficial for A. japonicus farming.

Botryandromyces, a morphology-based genus concept scrutinized by molecular data

Laboulbeniales (Ascomycota) are an order of understudied, biotrophic microfungi uniquely associated with arthropods. More than 2300 species are described but only a fraction of those have been sequenced. Molecular studies have shown that cryptic diversity and phenotypic plasticity are present within the Laboulbeniales. Thus far, all of the 146 genera described in Laboulbeniales have been based on morphological characteristics; features commonly used to delineate genera are the organization of receptacle cells and the number of perithecial outer wall cells. The genus Botryandromyces was erected to accommodate two species, B. heteroceri and B. ornatus (type), which share similar morphological characteristics and are different from other genera in their number of perithecial outer wall cells. Here, we generated sequences of multiple loci (18S, ITS, and 28S) of B. heteroceri and several Laboulbenia species. Our phylogenetic analyses retrieved Botryandromyces within Laboulbenia with high support. The two Botryandromyces species are similar to related Laboulbenia species in their upper receptacle (i.e., cells IV and V). We propose to transfer Botryandromyces ornatus and B. heteroceri to Laboulbenia as L. heteroceri and L. mairei nom. nov., respectively, due to a complicated taxonomic history. These results advocate the use of molecular data and the necessity of an integrative taxonomy approach in the study of Laboulbeniales not only to delineate species, but also to investigate relationships among species, genera, and higher taxa as well as to understand the evolution of morphology in this group of fungi.

Fossil Trichoptera embedded in mid-Cretaceous Burmese amber

The paper gives an overview of Trichoptera found as adults in mid-Cretaceous Burmese amber from about 100 million years ago. Fifty-eight extinct species are listed, three of which are still described here: Paduniella cretaceasp. nov., Palerasnitsynus vilarinoisp. nov., Palleptocerus kuranishiisp. nov. The extinct subfamily Palerasnitsyninaestat. nov. of the family Xiphocentronidae is established and the extinct Bipectinata orientaliscomb. nov. is transferred from the family Calamoceratidae to the family Odontoceridae. The extinct family LepidochlamidaeWang et al., 2022, stat. nov. is transferred to the superfamily Leptoceroidea. The fifty-eight caddisflies of Burmese amber are distributed among twenty-one genera and fourteen families, of which fifteen genera and four families are also extinct. The large time distance between extinct and extant organisms makes the assignment to the extant genera and families difficult, because the higher taxa are defined according to the species living today and often do not or hardly correspond to the earlier species and their adaptations. Furthermore, in line with the hypothesis of a Gondwanan origin of Burmese amber, some embedded Trichopterans are discussed as relict descendants of Gondwanan Trichoptera, e.g. the family Palleptoceridae and the Xiphocentronid subfamily Palerasnitsyninae.

Robustness of Felsenstein's Versus Transfer Bootstrap Supports With Respect to Taxon Sampling.

The bootstrap method is based on resampling sequence alignments and re-estimating trees. Felsenstein's bootstrap proportions (FBP) are the most common approach to assess the reliability and robustness of sequence-based phylogenies. However, when increasing taxon sampling (i.e., the number of sequences) to hundreds or thousands of taxa, FBP tend to return low support for deep branches. The transfer bootstrap expectation (TBE) has been recently suggested as an alternative to FBP. TBE is measured using a continuous transfer index in [0,1] for each bootstrap tree, instead of the binary {0,1} index used in FBP to measure the presence/absence of the branch of interest. TBE has been shown to yield higher and more informative supports while inducing a very low number of falsely supported branches. Nonetheless, it has been argued that TBE must be used with care due to sampling issues, especially in datasets with a high number of closely related taxa. In this study, we conduct multiple experiments by varying taxon sampling and comparing FBP and TBE support values on different phylogenetic depths, using empirical datasets. Our results show that the main critique of TBE stands in extreme cases with shallow branches and highly unbalanced sampling among clades, but that TBE is still robust in most cases, while FBP is inescapably negatively impacted by high taxon sampling. We suggest guidelines and good practices in TBE (and FBP) computing and interpretation.

Geometric Morphometric Analysis of Genus Chaetocnema (Coleoptera: Chrysomelidae: Alticini) with Insights on Its Subgenera Classification and Morphological Diversity

In taxonomy, qualitative methods are commonly used to analyze morphological characters, which can lead to dramatic changes in higher taxa. Geometric morphometrics (GM) has proven to be useful for discriminating species in various taxonomy groups. However, the application of geometric morphometrics in supraspecies classification is relatively scarce. In this study, we tested the controversial two subgenera classification of Chaetocnema with geometric morphometrics; a total of 203 Chaetocnema species representing 50% of all known species from around the world were selected for the analysis. We analyzed the shape of the pronotum, elytron, head, aedeagus, and spermatheca. The results showed that the two traditional subgenera distinctly differed from each other; therefore, we propose using two subgenera arrangements to facilitate the understanding and taxonomy of the Chaetocnema species (especially in the Oriental, Palearctic, and Nearctic regions). Additionally, the morphological diversity of the abovementioned structures of Chaetocnema was analyzed, and it was found that the highest morphological diversity was in the spermatheca, which was greater than that in the aedeagus. Our research demonstrated that GM could be useful for detecting morphological delimitation of the supraspecies taxa. It also showed that GM methods are applicable to insects as small as 2 mm in body size.

Clade density and the evolution of diversity-dependent diversification

The assumption of an ecological limit to the number of species in a given region is frequently invoked in evolutionary studies, yet its empirical basis is remarkably meager. We explore this assumption by integrating data on geographical distributions and phylogenetic relationships of nearly six thousand terrestrial vertebrate species. In particular, we test whether sympatry with closely-related species leads to decreasing speciation rates. We introduce the concept of clade density, which is the sum of the areas of overlap between a given species and other members of its higher taxon, weighted by their phylogenetic distance. Our results showed that, regardless of the chosen taxon and uncertainty in the phylogenetic relationships between the studied species, there is no significant relationship between clade density and speciation rate. We argue that the mechanistic foundation of diversity-dependent diversification is fragile, and that a better understanding of the mechanisms driving regional species pools is sorely needed.

1128-P: Changes in Gut Bacteriome Composition on Low-Carbohydrate Diet in Children with Type 1 Diabetes

Objectives: Low-carbohydrate diet (LCD) is a controversial but popular dietary choice for many children and adolescents with type 1 diabetes (CwD). In a cross-over trial with LCD (clinicaltrials.gov NCT05078658), we assessed whether even a short period of tightly controlled LCD is able to change the gut bacteriome in CwD. Methods: Twenty CwD (aged 15.1±3.0 years) were recruited into an intervention trial with a 5-week period of LCD (95±3 g carbs daily) followed by 5 weeks of regular carbohydrate diet (RCD) (193±18 g carbs daily) with the order randomized. The diets did not differ in energy intake (8360 vs. 8392 kJ, P=0.08). The fecal samples were collected regularly before, after and throughout the interventions (median number of samples collected per subject was 12, IQR 10-15). The fecal bacteriome was assessed using massively parallel sequencing of the variable regions V3-V4 of 16S rDNA. Mixed effects regression models were built where responses were principal components of the bacteriome community, alpha diversity indices and individual taxa. The predictors were the type of the diet, time since start of the diet and randomized order of the diets. Results: We observed shifts in the bacteriome community composition on the LCD which were apparent at all taxonomic levels (P for various principal components ranging from 5×10-4 to 0.015); their magnitude was however moderate. Of individual taxa, Bifidobacterium sp. and its higher taxonomic categories were negatively associated with LCD; the overall effects observed on the community composition were however broader than could be explained by changes in this single taxon. The alpha diversity decreased with time regardless of the intervention sequence, but did not associate with LCD. Conclusions: Even a short period of LCD is associated with subtle yet significant changes in the stool bacteriome community composition mainly in the Bifidobacterium sp. The observed changes may help us understand the possible effects of LCD on T1D. Disclosure V.Neuman: None. O.Cinek: None. L.Hlináková: None. L.Plachy: None. L.Petruzelkova: None. B.Obermannova: None. S.Pruhova: None. S.Kolouskova: None. J.Havlik: None. Z.Sumnik: None. Funding Czech Ministry of Health (AZVNU21-01-00085)

Clock-talk: have we forgotten about geographic variation?

Wyeomyia smithii, the pitcher-plant mosquito, has evolved from south to north and from low to high elevations in eastern North America. Along this seasonal gradient, critical photoperiod has increased while apparent involvement of the circadian clock has declined in concert with the evolutionary divergence of populations. Response to classical experiments used to test for a circadian basis of photoperiodism varies as much within and among populations of W. smithii as have been found in the majority of all other insects and mites. The micro-evolutionary processes revealed within and among populations of W. smithii, programmed by a complex underlying genetic architecture, illustrate a gateway to the macro-evolutionary divergence of biological timing among species and higher taxa in general.

HerpSexDet: the herpetological database of sex determination and sex reversal

Wildlife exhibits various sex-determination systems where sex chromosomes and environmental temperatures may both contribute to individual sexual development. The causes and consequences of this variability are important questions for evolutionary ecology, especially in light of ongoing environmental change. Amphibians and reptiles are emerging as a key group for studying these questions, with new data accumulating acceleratingly. We collected empirical data from earlier databases, reviews and primary literature to create the most up-to-date database on herpetological sex determination. We named our database HerpSexDet, which currently features data on genetic and temperature-dependent sex determination as well as reports on sex reversal for a total of 192 amphibian and 697 reptile species. This dataset, which we will regularly update in the future, facilitates interspecific comparative studies on the evolution of sex determination and its consequences for species-specific traits such as life history and conservation status, and may also help guiding future research by identifying species or higher taxa that are potentially most enlightening for the study of environmentally driven sex reversal.