Katayo Sagata

Integrative taxonomy on the fast track - towards more sustainability in biodiversity research

BackgroundA so called “taxonomic impediment” has been recognized as a major obstacle to biodiversity research for the past two decades. Numerous remedies were then proposed. However, neither significant progress in terms of formal species descriptions, nor a minimum standard for descriptions have been achieved so far. Here, we analyze the problems of traditional taxonomy which often produces keys and descriptions of limited practical value. We suggest that phylogenetics and phenetics had a subtle and so far unnoticed effect on taxonomy leading to inflated species descriptions.DiscussionThe term “turbo-taxonomy” was recently coined for an approach combining cox1 sequences, concise morphological descriptions by an expert taxonomist, and high-resolution digital imaging to streamline the formal description of larger numbers of new species. We propose a further development of this approach which, together with open access web-publication and automated pushing of content from journal into a wiki, may create the most efficient and sustainable way to conduct taxonomy in the future. On demand, highly concise descriptions can be gradually updated or modified in the fully versioned wiki-framework we use. This means that the visibility of additional data is not compromised, while the original species description -the first version- remains preserved in the wiki, and of course in the journal version. A DNA sequence database with an identification engine replaces an identification key, helps to avoid synonyms and has the potential to detect grossly incorrect generic placements. We demonstrate the functionality of a species-description pipeline by naming 101 new species of hyperdiverse New Guinea Trigonopterus weevils in the open-access journal ZooKeys.SummaryFast track taxonomy will not only increase speed, but also sustainability of global species inventories. It will be of great practical value to all the other disciplines that depend on a usable taxonomy and will change our perception of global biodiversity. While this approach is certainly not suitable for all taxa alike, it is the tool that will help to tackle many hyperdiverse groups and pave the road for more sustainable comparative studies, e.g. in community ecology, phylogeography and large scale biogeographic studies.

The towering orogeny of New Guinea as a trigger for arthropod megadiversity

Early studies on Melanesian mountain systems provided insights for fundamental evolutionary and ecological concepts. These island-like systems are thought to provide opportunities in the form of newly formed, competition-free niches. Here we show that a hyperdiverse radiation of freshwater arthropods originated in the emerging central New Guinea orogen, out of Australia, about 10 million years ago. Further diversification was mainly allopatric, with repeated more recent colonization of lowlands as they emerged in the form of colliding oceanic island arcs, continental fragments and the Papuan Peninsula, as well as recolonization of the central orogen. We unveil a constant and ongoing process of lineage accumulation while the carrying capacity of the island is about to be reached, suggesting that lineage diversification speed now exceeds that of landmass/new ecological opportunity formation. Therefore, the central orogeny of New Guinea acts as a motor of diversification for the entire region.

New Guinea highland origin of a widespread arthropod supertramp.

The biologically and geologically extremely diverse archipelagos of Wallacea, Australasia and Oceania have long stimulated ecologists and evolutionary biologists. Yet, few molecular phylogenetic analyses of the terrestrial fauna have been carried out to understand the evolutionary patterns. We use dense taxon and character sampling of more than 7000 bp DNA sequence data for a group of diving beetles ranging from the Holarctic throughout Asia to as far east as French Polynesia. We here show that an ecologically diverse, common and widespread (Portugal to New Zealand) arthropod supertramp species originated in the highlands of New Guinea, ca 6.0–2.7 Myr ago. The approximately 25 closely related species are narrow endemics in Australasia/Oceania. The ancestor of this clade colonized that region from Eurasia ca 9–7 Myr ago. Our finding contradicts the widely held view of local endemism as an evolutionary dead end, as we find multiple peripatric speciation events within the Pleistocene and complex colonization patterns between the Oriental and Australian zoogeographic regions, including the recolonization of Eurasia, jumping across Wallaces line and colonization of continental Australia out of New Guinea. Our study strongly highlights the importance of dispersal over water gaps in shaping biogeographic patterns.

DNA barcoding for community ecology--how to tackle a hyperdiverse, mostly undescribed Melanesian fauna.

Background Trigonopterus weevils are widely distributed throughout Melanesia and hyperdiverse in New Guinea. They are a dominant feature in natural forests, with narrow altitudinal zonation. Their use in community ecology has been precluded by the “taxonomic impediment”. Methodology/Principal Findings We sampled >6,500 specimens from seven areas across New Guinea; 1,002 specimens assigned to 270 morphospecies were DNA sequenced. Objective clustering of a refined dataset (excluding nine cryptic species) at 3% threshold revealed 324 genetic clusters (DNA group count relative to number of morphospecies = 20.0% overestimation of species diversity, or 120.0% agreement) and 85.6% taxonomic accuracy (the proportion of DNA groups that “perfectly” agree with morphology-based species hypotheses). Agreement and accuracy were best at an 8% threshold. GMYC analysis revealed 328 entities (21.5% overestimation) with 227 perfect GMYC entities (84.1% taxonomic accuracy). Both methods outperform the parataxonomist (19% underestimation; 31.6% taxonomic accuracy). The number of species found in more than one sampling area was highest in the Eastern Highlands and Huon (Sørensen similarity index 0.07, 4 shared species); ⅓ of all areas had no species overlap. Success rates of DNA barcoding methods were lowest when species showed a pronounced geographical structure. In general, Trigonopterus show high α and β-diversity across New Guinea. Conclusions/Significance DNA barcoding is an excellent tool for biodiversity surveys but success rates might drop when closer localities are included. Hyperdiverse Trigonopterus are a useful taxon for evaluating forest remnants in Melanesia, allowing finer-grained analyses than would be possible with vertebrate taxa commonly used to date. Our protocol should help establish other groups of hyperdiverse fauna as target taxa for community ecology. Sequencing delivers objective data on taxa of incredible diversity but mostly without a solid taxonomic foundation and should help pave the road for the eventual formal naming of new species.

One hundred and one new species of Trigonopterus weevils from New Guinea

Abstract A species discovery and description pipeline to accelerate and improve taxonomy is outlined, relying on concise expert descriptions, combined with DNA sequencing, digital imaging, and automated wiki species page creation from the journal. One hundred and one new species of Trigonopterus Fauvel, 1862 are described to demonstrate the feasibility of this approach: Trigonopterus aeneipennis sp. n., Trigonopterus aeneus sp. n., Trigonopterus agathis sp. n., Trigonopterus agilis sp. n., Trigonopterus amplipennis sp. n., Trigonopterus ancoruncus sp. n., Trigonopterus angulatus sp. n., Trigonopterus angustus sp. n., Trigonopterus apicalis sp. n., Trigonopterus armatus sp. n., Trigonopterus ascendens sp. n., Trigonopterus augur sp. n., Trigonopterus balimensis sp. n., Trigonopterus basalis sp. n., Trigonopterus conformis sp. n., Trigonopterus constrictus sp. n., Trigonopterus costatus sp. n., Trigonopterus costicollis sp. n., Trigonopterus crassicornis sp. n., Trigonopterus cuneipennis sp. n., Trigonopterus cyclopensis sp. n., Trigonopterus dentirostris sp. n., Trigonopterus discoidalis sp. n., Trigonopterus dromedarius sp. n., Trigonopterus durus sp. n., Trigonopterus echinus sp. n., Trigonopterus edaphus sp. n., Trigonopterus eremitus sp. n., Trigonopterus euops sp. n., Trigonopterus ferrugineus sp. n., Trigonopterus fusiformis sp. n., Trigonopterus glaber sp. n., Trigonopterus gonatoceros sp. n., Trigonopterus granum sp. n., Trigonopterus helios sp. n., Trigonopterus hitoloorum sp. n., Trigonopterus imitatus sp. n., Trigonopterus inflatus sp. n., Trigonopterus insularis sp. n., Trigonopterus irregularis sp. n., Trigonopterus ixodiformis sp. n., Trigonopterus kanawiorum sp. n., Trigonopterus katayoi sp. n., Trigonopterus koveorum sp. n., Trigonopterus kurulu sp. n., Trigonopterus lekiorum sp. n., Trigonopterus lineatus sp. n., Trigonopterus lineellus sp. n., Trigonopterus maculatus sp. n., Trigonopterus mimicus sp. n., Trigonopterus monticola sp. n., Trigonopterus montivagus sp. n., Trigonopterus moreaorum sp. n., Trigonopterus myops sp. n., Trigonopterus nangiorum sp. n., Trigonopterus nothofagorum sp. n., Trigonopterus ovatus sp. n., Trigonopterus oviformis sp. n., Trigonopterus parumsquamosus sp. n., Trigonopterus parvulus sp. n., Trigonopterus phoenix sp. n., Trigonopterus plicicollis sp. n., Trigonopterus politoides sp. n., Trigonopterus pseudogranum sp. n., Trigonopterus pseudonasutus sp. n., Trigonopterus ptolycoides sp. n., Trigonopterus punctulatus sp. n., Trigonopterus ragaorum sp. n., Trigonopterus rhinoceros sp. n., Trigonopterus rhomboidalis sp. n., Trigonopterus rubiginosus sp. n., Trigonopterus rubripennis sp. n., Trigonopterus rufibasis sp. n., Trigonopterus scabrosus sp. n., Trigonopterus scissops sp. n., Trigonopterus scharfi sp. n., Trigonopterus signicollis sp. n., Trigonopterus simulans sp. n., Trigonopterus soiorum sp. n., T sordidus sp. n., Trigonopterus squamirostris sp. n., Trigonopterus striatus sp. n., Trigonopterus strigatus sp. n., Trigonopterus strombosceroides sp. n., Trigonopterus subglabratus sp. n., Trigonopterus sulcatus sp. n., Trigonopterus taenzleri sp. n., Trigonopterus talpa sp. n., Trigonopterus taurekaorum sp. n., Trigonopterus tialeorum sp. n., Trigonopterus tibialis sp. n., Trigonopterus tridentatus sp. n., Trigonopterus uniformis sp. n., Trigonopterus variabilis sp. n., Trigonopterus velaris sp. n., Trigonopterus verrucosus sp. n., Trigonopterus violaceus sp. n., Trigonopterus viridescens sp. n., Trigonopterus wamenaensis sp. n., Trigonopterus wariorum sp. n., Trigonopterus zygops sp. n.. All new species are authored by the taxonomist-in-charge, Alexander Riedel.

Australasian sky islands act as a diversity pump facilitating peripheral speciation and complex reversal from narrow endemic to widespread ecological supertramp

The Australasian archipelago is biologically extremely diverse as a result of a highly puzzling geological and biological evolution. Unveiling the underlying mechanisms has never been more attainable as molecular phylogenetic and geological methods improve, and has become a research priority considering increasing human-mediated loss of biodiversity. However, studies of finer scaled evolutionary patterns remain rare particularly for megadiverse Melanesian biota. While oceanic islands have received some attention in the region, likewise insular mountain blocks that serve as species pumps remain understudied, even though Australasia, for example, features some of the most spectacular tropical alpine habitats in the World. Here, we sequenced almost 2 kb of mitochondrial DNA from the widespread diving beetle Rhantus suturalis from across Australasia and the Indomalayan Archipelago, including remote New Guinean highlands. Based on expert taxonomy with a multigene phylogenetic backbone study, and combining molecular phylogenetics, phylogeography, divergence time estimation, and historical demography, we recover comparably low geographic signal, but complex phylogenetic relationships and population structure within R. suturalis. Four narrowly endemic New Guinea highland species are subordinated and two populations (New Guinea, New Zealand) seem to constitute cases of ongoing speciation. We reveal repeated colonization of remote mountain chains where haplotypes out of a core clade of very widespread haplotypes syntopically might occur with well-isolated ones. These results are corroborated by a Pleistocene origin approximately 2.4 Ma ago, followed by a sudden demographic expansion 600,000 years ago that may have been initiated through climatic adaptations. This study is a snapshot of the early stages of lineage diversification by peripatric speciation in Australasia, and supports New Guinea sky islands as cradles of evolution, in line with geological evidence suggesting very recent origin of high altitudes in the region.

Five new species of the genus Papuadytes Balke, 1998 from New Guinea (Coleoptera: Dytiscidae)

Abstract Five new species of New Guinean Papuadytes Balke are described. Based on distally fused and modified ventral sclerites of the median lobe of the aedeagus, the P. broschii species group is suggested for P. broschii Balke, 1998, P. marinae sp. nov., and P. hintelmannae sp. nov. This group is only known from Papua New Guinea where the species occur allopatrically in different mountain ranges. The other new species are P. atowaso sp. nov., P. munaso sp. nov., and P. vladimiri sp. nov.

Description of 23 new species of the Exocelina ekari-group from New Guinea, with a key to all representatives of the species group (Coleoptera, Dytiscidae, Copelatinae)

Abstract Twenty three new species of Exocelina Broun, 1886 from New Guinea are described herein: Exocelina bewaniensis sp. n., Exocelina bismarckensis sp. n., Exocelina craterensis sp. n., Exocelina gorokaensis sp. n., Exocelina herowana sp. n., Exocelina jimiensis sp. n., Exocelina kisli sp. n., Exocelina ksionseki sp. n., Exocelina lembena sp. n., Exocelina mantembu sp. n., Exocelina michaelensis sp. n., Exocelina pinocchio sp. n., Exocelina pseudoastrophallus sp. n., Exocelina pseudobifida sp. n., Exocelina pseudoedeltraudae sp. n., Exocelina pseudoeme sp. n., Exocelina sandaunensis sp. n., Exocelina simbaiarea sp. n., Exocelina skalei sp. n., Exocelina tabubilensis sp. n., Exocelina tariensis sp. n., Exocelina vovai sp. n., and Exocelina wannangensis sp. n. All of them have been found to belong to the Exocelina ekari-group. An identification key to all known species of the group is provided, and important diagnostic characters (habitus, color, male antennae, protarsomeres 4–5, median lobes, and parameres) are illustrated. Data on the distribution of the new species and some already described species are given.

Description of two new species of the Exocelina broschii-group from Papua New Guinea, with revision and key to all representatives of this species group (Coleoptera, Dytiscidae, Copelatinae)

Abstract Two new species of Exocelina Broun, 1886 from Papua New Guinea are described herein: Exocelina mondmillensis sp. n. and Exocelina pseudomarinae sp. n. They are placed into the Exocelina broschii-group based on the shovel/fork-like ventral sclerites of their median lobe. While the former has rather distinct combination of the morphological characters (inconspicuous dorsal punctation, thin apex of the median lobe and ventral sclerite of the median lobe with two tips of different length), the latter is very similar to already described species Exocelina marinae (Shaverdo, Sagata & Balke, 2005). All described species of the group are revised and a key to their identification is provided. Important diagnostic characters (habitus, color, protarsomeres 4–5, median lobes, and parameres) are illustrated. Data on the distribution of all species of the group are given showing that its representatives occur only in Papua New Guinea and most of them are widely distributed in it central part.

The Effect of Temperature Increases on an Ant-Hemiptera-Plant Interaction.

Global temperature increases are significantly altering species distributions and the structure of ecological communities. However, the impact of temperature increases on multi- species interactions is poorly understood. We used an ant-Hemiptera-plant interaction to examine the potential outcomes of predicted temperature increases for each partner and for the availability of honeydew, a keystone resource in many forest ecosystems. We re-created this interaction in growth cabinets using predicted mean summer temperatures for Melbourne, Australia, for the years 2011 (23°C), 2050 (25°C) and 2100 (29°C), respectively, under an unmitigated greenhouse gas emission scenario. Plant growth and ant foraging activities increased, while scale insect growth, abundance and size, honeydew standing crop per tree and harvesting by ants decreased at 29°C, relative to lower temperatures (23 and 25°C). This led to decreased scale insect infestations of plants and reduced honeydew standing crop per tree at the highest temperature. At all temperatures, honeydew standing crop was lower when ants harvested the honeydew from scale insects, but the impact of ant harvesting was particularly significant at 29°C, where combined effects of temperature and ants reduced honeydew standing crop to below detectable levels. Although temperature increases in the next 35 years will have limited effects on this system, by the end of this century, warmer temperatures may cause the availability of honeydew to decline. Decline of honeydew may have far-reaching trophic effects on honeydew and ant-mediated interactions. However, field-based studies that consider the full complexity of ecosystems may be required to elucidate these impacts.