For several hundred years freshwater crayfish (Crustacea—Decapoda—Astacidea) have played an important ecological, cultural and culinary role in Scandinavia. However, many native populations of noble crayfish Astacus astacus have faced major declines during the last century, largely resulting from human assisted expansion of non-indigenous signal crayfish Pacifastacus leniusculus that carry and transmit the crayfish plague pathogen. In Denmark, also the non-indigenous narrow-clawed crayfish Astacus leptodactylus has expanded due to anthropogenic activities. Knowledge about crayfish distribution and early detection of non-indigenous and invasive species are crucial elements in successful conservation of indigenous crayfish. The use of environmental DNA (eDNA) extracted from water samples is a promising new tool for early and non-invasive detection of species in aquatic environments. In the present study, we have developed and tested quantitative PCR (qPCR) assays for species-specific detection and quantification of the three above mentioned crayfish species on the basis of mitochondrial cytochrome oxidase 1 (mtDNA-CO1), including separate assays for two clades of A. leptodactylus. The limit of detection (LOD) was experimentally established as 5 copies/PCR with two different approaches, and the limit of quantification (LOQ) were determined to 5 and 10 copies/PCR, respectively, depending on chosen approach. The assays detected crayfish in natural freshwater ecosystems with known populations of all three species, and show promising potentials for future monitoring of A. astacus, P. leniusculus and A. leptodactylus. However, the assays need further validation with data 1) comparing traditional and eDNA based estimates of abundance, and 2) representing a broader geographical range for the involved crayfish species.

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In wild populations negative effects from inbreeding are usually difficult to assess. The contemporary Scandinavian wolf population (Canis lupus) was established in 1983. With only three founders this population, with approximately 100 individuals, exhibits lower genetic variability than the neighbouring eastern population. Congenital malformations of the backbone were found in this highly inbred population. This study assesses the frequency and morphology of vertebral malformations within the Scandinavian wolf population and compares this with two reference populations. We discuss the etiology of malformations, how they may affect individuals and viability for the population. The frequencies of lumbosacral transitional vertebrae were higher in the small contemporary population than in the eastern reference population. Certain other defects were not found in the reference populations. This study demonstrates malformations that may have a negative impact on the Scandinavian wolf population and be an indication of inbreeding depression. For the conservation of this endangered population, we assert that immigration of wolves from eastern populations is essential.

Examples of photoluminescence (PL) are being reported with increasing frequency in a wide range of organisms from diverse ecosystems. However, the chemical basis of this PL remains poorly de ned, and our understanding of its potential ecological function is still super cial. Amongst mammals, recent analyses have identi ed free-base porphyrins as the compounds responsible for the reddish ultravioletinduced photoluminescence (UV-PL) observed in the pelage of springhares and hedgehogs. However, the localization of the pigments within the hair largely remains to be determined. Here we use photoluminescence multispectral imaging emission and excitation spectroscopy to detect, map and characterize porphyrinic compounds in skin appendages in situ. We also document new cases of mammalian UV-PL caused by free-base porphyrins in distantly related species. Spatial distribution of the UV-PL is strongly suggestive of an endogenous origin of the porphyrinic compounds. We argue that reddish UV-PL is predominantly observed in crepuscular and nocturnal mammals because porphyrins are photodegradable. Consequently, this phenomenon may not have a speci c function in intra-or interspeci c communication but rather represents a byproduct of potentially widespread physiological processes.

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