Search Results (4)

The European mink Mustela lutreola is one of the most threatened carnivores in Europe, having suffered dramatic range contractions and severe population fragmentation. Accurate knowledge of its genetic diversity is crucial for conservation planning, yet earlier studies based on partial mitochondrial markers offered limited resolution and often underestimated haplotype richness. In this study, complete mitochondrial genomes from four extant populations (Russia, n = 11; Romania, n = 16; Germany, n = 24; France–Spain, n = 15) were analysed using a suite of non-parametric and asymptotic estimators (Fisher’s α, ACE, Jackknife1, Bootstrap, Chao1-based iNEXT) together with negative binomial modelling. A total of 41 haplotypes were detected, but extrapolated estimates indicated substantially higher richness, particularly in populations dominated by singletons. Rarefaction and extrapolation analyses revealed that sample sizes of 70–130 individuals per population are needed to approach complete haplotype detection. The France–Spain and Romania populations harboured the highest predicted richness, whereas Germany and Russia, both represented by ex situ stocks, showed lower diversity. These results refine earlier assumptions of extreme homogeneity in the Western population and demonstrate that significant mitochondrial variation persists at the continental scale. The study provides quantitative benchmarks for sampling design and genetic management, supporting preservation of evolutionary potential in this critically endangered species. Full article

Anthropogenic disturbances, such as forest conversion, have a profound impact on species distributions and biodiversity in tropical forests. This study aimed to determine the diversity and distribution of bark and ambrosia beetles (Curculionidae: Scolytinae and Platypodinae) across three forest types: Primary Forest (PF), Disturbed Forest (DF), and Rubber Plantation (RP) in southern Sabah, Malaysia. We analyzed biweekly data obtained from ethanol-baited traps over three years, from April 2017 to May 2020, which included 7257 individuals from 154 species. The dominant species remained the same across all forest types. However, species composition was highly stochastic and unpredictable between forest types. The abundance and number of species were highest in RP but lowest in DF. Indigenous forest use in DF mostly for fuel likely reduced the resources for the beetles. Open canopy structure in RP probably increased the number of flying beetles. Although adjacent to PF, RP displayed a distinct species composition predominantly associated with rubber trees. These findings underscore the anthropogenic impact on beetle assemblages due to forest use and emphasize the need for sustainable forest management practices to prevent biodiversity loss and maintain ecosystem stability. Full article

Accurate assessment of macrophyte diversity is essential for effective river ecosystem management. Discrepancies in sampling protocols can lead to variations in observed biodiversity, which may influence ecological monitoring and management strategies. This study evaluates and compares three sampling methods—the comprehensive “all” survey, Joint Danube Survey (JDS), and National Monitoring Program (NMP)—for assessing macrophyte diversity along the Serbian Danube. We applied Hill numbers and Chao estimators to evaluate sample completeness and diversity for species richness (q = 0), Shannon (q = 1), and Simpson (q = 2) diversity. Asymptotic diversity was estimated using rarefaction and extrapolation methods, and statistical analyses (ANOVA, permutation tests) assessed differences in diversity estimates across sampling methods. The “all” sampling method provided the highest sample completeness and reliable asymptotic diversity estimates, capturing 100% completeness for q = 1 and q = 2. The JDS and NMP datasets showed incomplete sampling for species richness (q = 0), with undetected species richness in both. However, both datasets captured all abundant species for higher diversity orders. Significant differences in diversity estimates between methods were found in some waterbodies, especially for species richness and Shannon diversity. The “all” sampling method most accurately captures true species richness and diversity. While JDS and NMP methods are valuable for assessing higher-order diversity, the two methods may underestimate species richness, particularly in heterogeneous river sections. Full article

Onchocerciasis is a neglected tropical disease targeted for elimination using ivermectin mass administration. Ivermectin kills the microfilariae and temporarily arrests microfilariae production by the macrofilariae. We genotyped 436 microfilariae from 10 people each in Ituri, Democratic Republic of the Congo (DRC), and Maridi County, South Sudan, collected before and 4–5 months after ivermectin treatment. Population genetic analyses identified 52 and 103 mitochondrial DNA haplotypes among the microfilariae from DRC and South Sudan, respectively, with few haplotypes shared between people. The percentage of genotype-based correct assignment to person within DRC was ~88% and within South Sudan ~64%. Rarefaction and extrapolation analysis showed that the genetic diversity in DRC, and even more so in South Sudan, was captured incompletely. The results indicate that the per-person adult worm burden is likely higher in South Sudan than DRC. Analyses of haplotype data from a subsample (n = 4) did not discriminate genetically between pre- and post-treatment microfilariae, confirming that post-treatment microfilariae are not the result of new infections. With appropriate sampling, mitochondrial haplotype analysis could help monitor changes in the number of macrofilariae in a population as a result of treatment, identify cases of potential treatment failure, and detect new infections as an indicator of continuing transmission. Full article