Milan Veselý

For decades, there has been taxonomic confusion regarding the identity of Colostethus pratti -like frogs occurring in Panama. By including a sample from the close vicinity of the type locality of C. pratti (Valdivia, Colombia), we revealed that these Panamanian frogs instead form a monophyletic clade sister to C. latinasus . Using an integrative approach combining mitochondrial and nuclear DNA markers, bioacoustics, morphology, and geographical distribution, we describe these lineages herein as six new species: Colostethus bocatoro sp. nov ., C. donosensis sp. nov ., C. kuara sp. nov ., C. portobelensis sp. nov ., C. sanblasensis sp. nov ., and C. chucantiensis sp. nov . Based on divergence-time estimates, we further discuss the potential timespan of dispersal from South America in relation to the formation of the Isthmus. Our findings highlight the role of geographical isolation in driving divergence of reproductive signals and generating cryptic amphibian diversity across the Isthmus of Panama. Much of this diversity likely remains undiscovered, underscoring the urgent need for further research and conservation attention in the region.

Reproduction entirely without males is exceptionally rare among vertebrates. Recently, an enigmatic all-female lineage of casquehead lizards, initially thought to be a captive anomaly, appeared in zoos. During a targeted expedition to Honduras, we discovered two wild, asexually reproducing populations near the type locality of Laemanctus julioi, a species originally described from a single female. Using a de novo phased long-read genome and cytogenetics, we reveal these lizards are clonal hybrids, originating from two geographically separated sexual species that diverged 12 million years ago. We confirmed two independent clonal lineages, one matching the zoo population. To form clonal eggs, these lizards duplicate their genome before meiosis. Experimental breeding with a male from a paternal species produced non-viable offspring with increased genome size, suggesting these clones established themselves by remaining isolated from parental species. As the largest-bodied known vertebrates reproducing exclusively without males, these lizards demonstrate that radically different reproductive strategies can remain undetected even in highly conspicuous animals.

Sex determination was once thought to be unstable in ectothermic vertebrates, but several highly diversified groups of non-avian reptiles, such as iguanas sensu lato (Pleurodonta), appear to have conserved sex chromosomes. However, this statement has been criticized as being based on a parsimonious conclusion from limited sampling. Here, we tested sex chromosome homology in a further 35 species of pleurodont lizards, mainly of the family Anolidae. We demonstrated sex chromosome homology based on the comparison of the gene dosage of X-specific genes by quantitative PCR. Including these new data, the homology of sex chromosomes has so far been reported in 92 out of over 1,200 recently recognized species of Pleurodonta. The very conserved sex chromosomes in all but one family are at least as old as the basal split of Pleurodonta (estimated over 90 million years). In the case of the family Corytophanidae, all genera share different XX/XY sex chromosomes, which are thus over 25 million years old. We discuss the efficiency and limitations of the approach used for tests of the homology of sex chromosomes, as well as the reasons for the evolutionary stability of sex chromosomes in some lineages. We argue that to obtain a complete picture, all extant species should be tested for homology; however, until we reach this ambitious goal, parsimonious estimates in lineages where fragmentary data suggest stability of sex chromosomes, as in Pleurodonta, are substantiated.

The skin is a barrier between the internal and external environment of an organism. Depending on the species, it participates in multiple functions. The skin is the organ that holds the body together, covers and protects it, and provides communication with its environment. It is also the body's primary line of defense, especially for anamniotes. All vertebrates have multilayered skin composed of three main layers: the epidermis, the dermis, and the hypodermis. The vital mission of the integument in aquatic vertebrates is mucus secretion. Cornification began in apmhibians, improved in reptilians, and endured in avian and mammalian epidermis. The feather, the most ostentatious and functional structure of avian skin, evolved in the Mesozoic period. After the extinction of the dinosaurs, birds continued to diversify, followed by the enlargement, expansion, and diversification of mammals, which brings us to the most complicated skin organization of mammals with differing glands, cells, physiological pathways, and the evolution of hair. Throughout these radical changes, some features were preserved among classes such as basic dermal structure, pigment cell types, basic coloration genetics, and similar sensory features, which enable us to track the evolutionary path. The structural and physiological properties of the skin in all classes of vertebrates are presented. The purpose of this review is to go all the way back to the agnathans and follow the path step by step up to mammals to provide a comparative large and updated survey about vertebrate skin in terms of morphology, physiology, genetics, ecology, and immunology.

Substantial molecular and morphological character differences lead us to the description of a new species of the genusPristimantisfrom the cloud forest of Cerro Chucantí, Maje Mountains, Darien Province, as well as from several other mountain ranges in eastern and central Panama.Pristimantis gretathunbergaesp. nov.is a sister species to the allopatricP. erythropleura-penelopusgroup from northern Colombia with a mtDNA sequence divergence of > 4.4% at 16S and > 14.6% at COI. Its closest congener in sympatry isP. cruentusthat differs by a large sequence divergence of > 9.6% in 16S mtDNA and 19.0% at COI, and from which it differs also by ventral and groin coloration, unusually prominent black eyes, a contrasting light upper lip, commonly a single conical to spine-like tubercle on the upper eyelid, and a larger head. While the habitat continuity at most sites in eastern Panama is moderate, habitats in central Panama are severely fragmented. Cerro Chucantí and the surrounding Maje Mountains are highly threatened by rapid deforestation and replaced by plantations and cattle pastures. Thus, investigations on the ecology of the new species and its population status, especially at the type locality, are highly recommended. As a flagship species, this new frog can help to preserve the Chucantí cloud forest including several recently described species known only from this isolated area in eastern Panama.

Acta Carpathica Occidentalis, peer-reviewed scientific journal - results of original natural science research in natural sciences, especially from the Carpathian region of the Czech and Slovak Republics.

Some carabid species are not restricted to a single habitat only, but use various types of habitats. In these species, relatively little is known about the utilization of occupied habitats and factors affecting their movement within these habitats. In this study, we focus on the movement activity of ubiquitousCarabus ullrichiiduring its reproductive period at the border of two types of habitats, a meadow and a forest. We tracked 21 adult individuals using radio telemetry and recorded in total 1,687 position fixes. Movement activity was associated with the type of habitat and specific environmental conditions such as time of the day and air temperature. Both sexes activated preferably at dusk and during the night, although males were most active at temperatures around 15°C, while females showed no preference for temperature. Males were able to walk as fast as females, but they were more associated with forest edge. We assume that the inner edge of the forest could be used as a mating site and after mating males stay there and wait for new females with which to mate, while fertilized females disperse into the surroundings. They moved further into the closed forest where they were likely looking for oviposition sites and food resources to support reproduction. Exclusively females were recorded to visit the meadow at a greater distance from the forest edge and their movements there were almost always direct.

Agricultural intensification is a leading cause of global biodiversity loss, which can reduce the provisioning of ecosystem services in managed ecosystems. Organic farming and plant diversification are farm management schemes that may mitigate potential ecological harm by increasing species richness and boosting related ecosystem services to agroecosystems. What remains unclear is the extent to which farm management schemes affect biodiversity components other than species richness, and whether impacts differ across spatial scales and landscape contexts. Using a global metadataset, we quantified the effects of organic farming and plant diversification on abundance, local diversity (communities within fields), and regional diversity (communities across fields) of arthropod pollinators, predators, herbivores, and detritivores. Both organic farming and higher in‐field plant diversity enhanced arthropod abundance, particularly for rare taxa. This resulted in increased richness but decreased evenness. While these responses were stronger at local relative to regional scales, richness and abundance increased at both scales, and richness on farms embedded in complex relative to simple landscapes. Overall, both organic farming and in‐field plant diversification exerted the strongest effects on pollinators and predators, suggesting these management schemes can facilitate ecosystem service providers without augmenting herbivore (pest) populations. Our results suggest that organic farming and plant diversification promote diverse arthropod metacommunities that may provide temporal and spatial stability of ecosystem service provisioning. Conserving diverse plant and arthropod communities in farming systems therefore requires sustainable practices that operate both within fields and across landscapes.