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One of the notable features of penguin evolution is the occurrence of very large species in the early Cenozoic, whose body size greatly exceeded that of the largest extant penguins. Here we describe a new giant species from the late Paleocene of New Zealand that documents the very early evolution of large body size in penguins. Kumimanu biceae, n. gen. et sp. is larger than all other fossil penguins that have substantial skeletal portions preserved. Several plesiomorphic features place the new species outside a clade including all post-Paleocene giant penguins. It is phylogenetically separated from giant Eocene and Oligocene penguin species by various smaller taxa, which indicates multiple origins of giant size in penguin evolution. That a penguin rivaling the largest previously known species existed in the Paleocene suggests that gigantism in penguins arose shortly after these birds became flightless divers. Our study therefore strengthens previous suggestions that the absence of very large penguins today is likely due to the Oligo-Miocene radiation of marine mammals.
Solenogastres (Aplacophora) is a small clade of marine, shell-less worm-molluscs with close to 300 valid species. Their distribution ranges across all oceans, and whereas the vast majority of species has been collected and described from the continental shelf and slope, only few species are known from depths below 4,000 m. Following traditional taxonomy, identification of specimens to species level is complex and time-consuming and requires detailed investigations of morphology and anatomy—often resulting in the exclusion of the clade in biodiversity or biogeographic studies. During the KuramBio expedition (Kuril-Kamchatka Biodiversity Studies) to the abyssal plain of the Northwest Pacific and the Kuril-Kamchatka Trench, 33 solenogaster specimens were sampled from 4,830 m to 5,397 m. Within this study we present an efficient workflow to address solenogaster diversity, even when confronted with a high degree of singletons and minute body sizes, hampering the use of single individuals for multiple morphological and molecular approaches. We combine analyses of external characters and scleritome with molecular barcoding based on a self-designed solenogaster specific set of mitochondrial primers. Overall we were able to delineate at least 19 solenogaster lineages and identify 15 species to family level and beyond. Based on our approach we identified three key lineages from the two regionally most species-rich families (Acanthomeniidae and Pruvotinidae) for deeper taxonomic investigations and describe the novel abyssal species Amboherpia abyssokurilensis sp. nov. (Cavibelonia, Acanthomeniidae) using microanatomical 3D-reconstructions. Our study more than doubles the previous records of solenogaster species from the Northwest Pacific and its marginal seas. Almost all lineages are reported for the first time from the region of the (Northwest) Pacific, vastly expanding distribution ranges of the respective clades. Moreover it doubles the number of Solenogastres collected from abyssal depths on a global scale and underlines the lack of exploratory α-diversity work in the abyssal zone for reliable species estimates in marine biodiversity.
Molluscs are the second most species-rich phylum in the animal kingdom, yet only 11 genomes of this group have been published so far. Here, we present the draft genome sequence of the pulmonate freshwater snail Radix auricularia. Six whole genome shotgun libraries with different layouts were sequenced. The resulting assembly comprises 4,823 scaffolds with a cumulative length of 910 Mb and an overall read coverage of 72×. The assembly contains 94.6% of a metazoan core gene collection, indicating an almost complete coverage of the coding fraction. The discrepancy of ∼690 Mb compared with the estimated genome size of R. auricularia (1.6 Gb) results from a high repeat content of 70% mainly comprising DNA transposons. The annotation of 17,338 protein coding genes was supported by the use of publicly available transcriptome data. This draft will serve as starting point for further genomic and population genetic research in this scientifically important phylum.
Molluscs are the second most species-rich phylum in the animal kingdom, yet only eleven genomes of this group have been published so far. Here, we present the draft genome sequence of the pulmonate freshwater snail Radix auricularia. Six whole genome shotgun libraries with different layouts were sequenced. The resulting assembly comprises 4,823 scaffolds with a cumulative length of 910 Mb and an overall read coverage of 72x. The assembly contains 94.6 % of a metazoan core gene collection, indicating an almost complete coverage of the coding fraction. The discrepancy of ~690 Mb compared to the estimated genome size of R. auricularia (1.6 Gb) results from a high repeat content of 70 % mainly comprising DNA transposons. The annotation of 17,338 protein coding genes was supported by the use of publicly-available transcriptome data. This draft will serve as starting point for further genomic and population genetic research in this scientifically important phylum.
A large reef manta ray (Manta alfredi) aggregation has been observed off the north Sudanese Red Sea coast since the 1950s. Sightings have been predominantly within the boundaries of a marine protected area (MPA), which was designated a UNESCO World Heritage Site in July 2016. Contrasting economic development trajectories have been proposed for the area (small-scale ecotourism and large-scale island development). To examine space-use, Wildlife Computers® SPOT 5 tags were secured to three manta rays. A two-state switching Bayesian state space model (BSSM), that allowed movement parameters to switch between resident and travelling, was fit to the recorded locations, and 50% and 95% kernel utilization distributions (KUD) home ranges calculated. A total of 682 BSSM locations were recorded between 30 October 2012 and 6 November 2013. Of these, 98.5% fell within the MPA boundaries; 99.5% for manta 1, 91.5% for manta 2, and 100% for manta 3. The BSSM identified that all three mantas were resident during 99% of transmissions, with 50% and 95% KUD home ranges falling mainly within the MPA boundaries. For all three mantas combined (88.4%), and all individuals (manta 1–92.4%, manta 2–64.9%, manta 3–91.9%), the majority of locations occurred within 15 km of the proposed large-scale island development. Results indicated that the MPA boundaries are spatially appropriate for manta rays in the region, however, a close association to the proposed large-scale development highlights the potential threat of disruption. Conversely, the focused nature of spatial use highlights the potential for reliable ecotourism opportunities.
Fossil dental remains are an archive of unique information for paleobiological studies. Computed microtomography based on X-ray microfocus sources (X-μCT) and Synchrotron Radiation (SR-μCT) allow subtle quantification at the micron and sub-micron scale of the meso- and microstructural signature imprinted in the mineralized tissues, such as enamel and dentine, through high-resolution “virtual histology”. Nonetheless, depending on the degree of alterations undergone during fossilization, X-ray analyses of tooth tissues do not always provide distinct imaging contrasts, thus preventing the extraction of essential morphological and anatomical details. We illustrate here by three examples the successful application of neutron microtomography (n-μCT) in cases where X-rays have previously failed to deliver contrasts between dental tissues of fossilized specimen.
Reticulate evolution is considered to be among the main mechanisms of plant evolution, often leading to the establishment of new species. However, complex evolutionary scenarios result in a challenging definition of evolutionary and taxonomic units. In this study, we aimed to examine the evolutionary origin and revise the species status of Campanula baumgartenii, a rare endemic species from the polyploid complex Campanula section Heterophylla. Morphometry, flow cytometric ploidy estimation, amplified fragment length polymorphisms (AFLPs), as well as chloroplast and nuclear DNA sequence markers were used to assess the morphological and genetic differentiation among C. baumgartenii, Campanula rotundifolia and other closely related taxa. Tetra- and hexaploid C. baumgartenii is morphologically and molecularly (AFLP) differentiated from sympatric C. rotundifolia. Contrasting signals from nuclear (ITS) and chloroplast (trnL-rpl32) markers suggest a hybrid origin of C. baumgartenii with C. rotundifolia and a taxon related to the alpine Campanula scheuchzeri as ancestors. Additionally, hexaploid C. baumgartenii currently hybridizes with co-occurring tetraploid C. rotundifolia resulting in pentaploid hybrids, for which C. baumgartenii serves as both seed and pollen donor. Based on the molecular and morphological differentiation, we propose to keep C. baumgartenii as a separate species. This study exemplifies that detailed population genetic studies can provide a solid basis for taxonomic delimitation within Campanula section Heterophylla as well as for sound identification of conservation targets.
Background: The Aedes (Stegomyia) albopictus subgroup includes 11 cryptic species of which Ae. albopictus is the most widely distributed. Its global expansion associated with a documented vector competence for several emerging arboviruses raise obvious concerns in the recently colonized regions. While several studies have provided important insights regarding medical importance of Ae. albopicus, the investigations of the other sibling species are scarce. In Asia, indigenous populations within the Ae. albopictus subgroup can be found in sympatry. In the present study, we aimed to describe and compare molecular, morphological and bacterial symbionts composition among sympatric individuals from the Ae. albopictus subgroup inhabiting a Vietnamese protected area.
Results: Based on morphological structure of the cibarial armarture, we identified a cryptic species in the forest park at Bù Gia Mập in the south-eastern region of Vietnam. Analysis of nuclear (ITS1-5.8S-ITS2) and mitochondrial (cox1, nad5) markers confirmed the divergence between the cryptic species and Ae. albopictus. Analysis of midgut bacterial microbiota revealed a strong similarity among the two species with a notable difference; contrary to Ae. albopictus, the cryptic species did not harbour any Wolbachia infection.
Conclusions: These results could reflect either a recent invasion of Wolbachia in Ae. albopictus or alternatively a loss of this symbiont in the cryptic species. We argue that neglected species of the Ae. albopictus subgroup are of main importance in order to estimate variation of host-symbionts interactions across evolution.
Climate change indicators are tools to assess, visualize and communicate the impacts of climate change on species and communities. Indicators that can be applied to different taxa are particularly useful because they allow comparative analysis to identify which kinds of species are being more affected. A general prediction, supported by empirical data, is that the abundance of warm-adapted species should increase over time, relative to the cool-adapted ones within communities, under increasing ambient temperatures. The community temperature index (CTI) is a community weighted mean of species’ temperature preferences and has been used as an indicator to summarize this temporal shift. The CTI has the advantages of being a simple and generalizable indicator; however, a core problem is that temporal trends in the CTI may not only reflect changes in temperature. This is because species’ temperature preferences often covary with other species attributes, and these other attributes may affect species response to other environmental drivers. Here, we propose a novel model-based approach that separates the effects of temperature preference from the effects of other species attributes on species’ abundances and subsequently on the CTI. Using long-term population data of breeding birds in Denmark and demersal marine fish in the southeastern North Sea, we find differences in CTI trends with the original approach and our model-based approach, which may affect interpretation of climate change impacts. We suggest that our method can be used to test the robustness of CTI trends to the possible effects of other drivers of change, apart from climate change.
Background: Taxonomy offers precise species identification and delimitation and thus provides basic information for biological research, e.g. through assessment of species richness. The importance of molecular taxonomy, i.e., the identification and delimitation of taxa based on molecular markers, has increased in the past decade. Recently developed exploratory tools now allow estimating species-level diversity in multi-locus molecular datasets.
Results: Here we use molecular species delimitation tools that either quantify differences in intra- and interspecific variability of loci, or divergence times within and between species, or perform coalescent species tree inference to estimate species-level entities in molecular genetic datasets. We benchmark results from these methods against 14 morphologically readily differentiable species of a well-defined subgroup of the diverse Drusinae subfamily (Trichoptera, Limnephilidae). Using a 3798 bp (6 loci) molecular data set we aim to corroborate a geographically isolated new species by integrating comparative morphological studies and molecular taxonomy.
Conclusions: Our results indicate that only multi-locus species delimitation provides taxonomically relevant information. The data further corroborate the new species Drusus zivici sp. nov. We provide differential diagnostic characters and describe the male, female and larva of this new species and discuss diversity patterns of Drusinae in the Balkans. We further discuss potential and significance of molecular species delimitation. Finally we argue that enhancing collaborative integrative taxonomy will accelerate assessment of global diversity and completion of reference libraries for applied fields, e.g., conservation and biomonitoring.