Europe's obligate cave-dwelling amphibian Proteus anguinus inhabits subterranean waters of the north-western Balkan Peninsula. Because only fragments of its habitat are accessible to humans, this ...endangered salamander's exact distribution has been difficult to establish. Here we introduce a quantitative real time polymerase chain reaction-based environmental DNA (eDNA) approach to detect the presence of Proteus using water samples collected from karst springs, wells or caves. In a survey conducted along the southern limit of its known range, we established a likely presence of Proteus at seven new sites, extending its range to Montenegro. Next, using specific molecular probes to discriminate the rare black morph of Proteus from the closely related white morph, we detected its eDNA at five new sites, thus more than doubling the known number of sites. In one of these we found both black and white Proteus eDNA together. This finding suggests that the two morphs may live in contact with each other in the same body of groundwater and that they may be reproductively isolated species. Our results show that the eDNA approach is suitable and efficient in addressing questions in biogeography, evolution, taxonomy and conservation of the cryptic subterranean fauna.
North American Late Cretaceous salamanders are principally known by isolated atlantes and trunk vertebrae. Here I describe a new genus and species of fossil salamander, Paranecturus garbanii, gen. et ...sp. nov., based on these elements from the lower portions of the Hell Creek Formation (Maastrichtian), Garfield County, northeastern Montana, U.S.A. It is diagnosed by a unique combination of character states that include the presence of an alar-like process of the atlas and a groove on the posterior face of the neural arch and solid dorsal rib-bearers of the trunk vertebrae. My phylogenetic analysis of 13 caudate taxa and 23 atlantal and trunk vertebral characters recovered P. garbanii as a member of the Proteidae. P. garbanii represents the oldest fossil record of the Proteidae and demonstrates that this lineage was present before the Cretaceous-Paleogene mass extinction event.
In comparison to biodiversity on Earth's surface, subterranean biodiversity has largely remained concealed. The olm (Proteus anguinus) is one of the most enigmatic extant cave inhabitants, and until ...now little was known regarding its genetic structure and evolutionary history. Olms inhabit subterranean waters throughout the Dinaric Karst of the western Balkans, with a seemingly uniform phenotypic appearance of cave‐specialized traits: an elongate body, snout and limbs, degenerated eyes and loss of pigmentation (“white olm”). Only a single small region in southeastern Slovenia harbours olms with a phenotype typical of surface animals: pigmented skin, eyes, a blunt snout and short limbs (“black olm”). We used a combination of mitochondrial DNA and genome‐wide single nucleotide polymorphism data to investigate the molecular diversity, evolutionary history and biogeography of olms along the Dinaric Karst. We found nine deeply divergent species‐level lineages that separated between 17 and 4 million years ago, while molecular diversity within lineages was low. We detected no signal of recent admixture between lineages and only limited historical gene flow. Biogeographically, the contemporaneous distribution of lineages mostly mirrors hydrologically separated subterranean environments, while the historical separation of olm lineages follows microtectonic and climatic changes in the area. The reconstructed phylogeny suggests at least four independent transitions to the cave phenotype. Two of the species‐level lineages have miniscule ranges and may represent Europe's rarest amphibians. Their rarity and the decline in other lineages call for protection of their subterranean habitats.
Deciphering the genetic code of organisms with unusual phenotypes can help answer fundamental biological questions and provide insight into mechanisms relevant to human biomedical research. The cave ...salamander Proteus anguinus (Urodela: Proteidae), also known as the olm, is an example of a species with unique morphological and physiological adaptations to its subterranean environment, including regenerative abilities, resistance to prolonged starvation, and a life span of more than 100 years. However, the structure and sequence of the olm genome is still largely unknown owing to its enormous size, estimated at nearly 50 gigabases. An international Proteus Genome Research Consortium has been formed to decipher the olm genome. This perspective provides the scientific and biomedical rationale for exploring the olm genome and outlines potential outcomes, challenges, and methodological approaches required to analyze and annotate the genome of this unique amphibian.
An international Proteus Genome Research Consortium has been formed to decipher the genome of Proteus anguinus (the olm). This perspective provides the scientific and biomedical rationale for exploring the olm genome and outlines potential outcomes, challenges, and methodological approaches required to analyze and annotate the genome of this unique amphibian.
Acanthocephalus balkanicus Batchvarov et Combes, 1974 was incompletely described from the northern crested newt, Triturus cristatus (Laurenti) (Amphibia: Salamandridae), a possible synonym of the ...Balkan crested newt, Triturus ivanbureschi Arntzen et Wielstra, from a pond in village of Pesnopoy, southern Bulgaria. We provide a full description of adult males and females of the same taxon from the olm, Proteus anguinus Laurenti (Amphibia: Proteidae), the only exclusively aquatic cave-dwelling vertebrate in Europe, captured in Postojna-Planina Cave System in Slovenia. Cystacanths were also collected from the cave ecomorph of Asellus aquaticus (Linnaeus) (Crustacea: Asellidae) in the same location. Molecular analysis of specimens from Slovenia revealed that they are genetically almost identical to those of Acanthocephalus anguillae (Müller, 1780), a common parasite of European freshwater fishes. We propose to recognise the morphological and host differences by describing A. balkanicus as a new subspecies of A. anguillae. Acanthocephalus anguillae balkanicus is rather small and cylindrical with cylindrical proboscis having 10 rows of 6 hooks with simple roots each, long neck, large balloon-shaped lemnisci, small spherical anterior testis, and 6 club-shaped cement glands in 3 pairs. SEM images reveal more morphological details and the X-ray scans of gallium cut hooks shows considerably higher levels of phosphorus and calcium in adult hooks than in cystacanth hooks, especially in basal areas. Sulfur levels were higher in the arch and basal area of cystacanth hooks than adult hooks. Considering that both definitive and intermediate hosts of the Slovenian population of this acanthocephalan are bound to cave life, it is possible that its entire life cycle is uniquely completed underground.
Predator-prey interactions are among the most important biotic interactions shaping ecological communities and driving the evolution of defensive traits. These interactions and their effects on ...species received little attention in extreme and remote environments, where possibilities for direct observations and experimental manipulation of the animals are limited. In this paper, we study such type of environment, namely caves of the Dinarides (Europe), combining spatial and phylogenetic methods. We focused on several species of Niphargus amphipods living in phreatic lakes, as some of them use the dorsal spines as putative morphological defensive traits. We predicted that these spines represent a defense strategy against the olm (Proteus anguinus), a top predator species in the subterranean waters. We tested for spatial overlap of the olm and Niphargus species and showed that spined species live in closer proximity to and co-occur more frequently with the olm than non-spined species. Modeling of the evolution of the spines onto Niphargus phylogeny implies coevolution of this trait in the presence of olm. We conclude that these spines likely evolved as defensive traits in a predator-prey arms race. Combining multiple analyses, we provide an example for a methodological framework to assess predator-prey interactions when in-situ or laboratory observations are not possible.
The biology of cave‐dwelling species is a fascinating area, yet it is understudied due to logistic constraints, especially in regard to aquatic organisms. The olm (Proteus anguinus) is the largest ...known troglobiont vertebrate, showing extreme life‐history characteristics such as a possible lifespan of over 100 years and a reproductive cycle of over 12 years. However, most studies carried out on the species to date are based on laboratory studies, resulting in a severe lack of ecological data from natural populations studied in their original habitat. We applied a capture–mark–recapture approach on an Eastern Herzegovinian population for eight years to reveal its spatial strategy and general movement patterns. We found that P. anguinus is sedentary, can often be found within a few square metres over several years, and their moving distance is uncorrelated with the time elapsed between recaptures. Previous laboratory studies constrained to confined space and artificial environments have already suggested site fidelity and our results from a natural population confirm this. The low reproductive activity of the species together with the reported extreme site fidelity makes this top predator of aquatic cave communities highly vulnerable and a sensitive bio‐indicator of habitat‐changing human activities.
This is the first capture–mark–recapture study on a natural population of the obligate aquatic cave‐dwelling olm (Proteus anguinus), known for its extreme life‐history characteristics (lifespan over 100 years, reproductive cycle over 10 years). We observed extreme site fidelity; individuals moved typically less than 15 m over years.
Proteus, matrine, and pyridalyl were tested in the laboratory for their effects upon Orius laevigatus (Fieber), which is a polyphagous predator used for IPM programs of Frankliniella occidentalis ...(Pergande). Against female adults, the most toxic insecticide was Proteus (LC50 = 44.3 µl L–1), followed by pyridalyl (LC50 = 83.8 µl L–1) and matrine (LC50 = 102.7 µl L–1). The mortality of female adults was checked 24, 48, 72, and 96 h after exposure to 14-d residues of the treatments on strawberry leaves. The residual of Proteus was less toxic; the remaining products caused the lowest mortality at different times after exposure. Sublethal treatments (LC25) significantly prolonged the developmental duration of total immature stages from 17.6 d in control to 21.6 and 20.0 d in Proteus and pyridalyl treatments, respectively. Also, the fecundity of O. laevigatus treated with Proteus, pyridalyl, and matrine decreased to 58.8%, 75.6%, and 96.7%, respectively, in comparison to the control. Compared with the control population (0.118 d–1), the intrinsic rate of increase (r) of F1 generation decreased by 0.053, 0.095, and 0.110 d–1 in Proteus, pyridalyl, and matrine treatments, respectively. The consumption rate of control bugs reached 14.0 thrips during 24 h. The adults fed on Proteus treatment had the lowest consumption rate in this period (9.4 preys). Overall, matrine proved to be harmless with reproductive capacity and r similar to what was recorded in control bugs. We concluded that matrine can be used as an alternative for the synthetic insecticide to integrate with O. laevigatus.
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