A global agenda for advancing freshwater biodiversity research.

Global freshwater biodiversity is declining dramatically, and meeting the challenges of this crisis requires bold goals and the mobilisation of substantial resources. While the reasons are varied, investments in both research and conservation of freshwater biodiversity lag far behind those in the terrestrial and marine realms. Inspired by a global consultation, we identify 15 pressing priority needs, grouped into five research areas, in an effort to support informed stewardship of freshwater biodiversity. The proposed agenda aims to advance freshwater biodiversity research globally as a critical step in improving coordinated actions towards its sustainable management and conservation.

Two new species of Anacaena Thomson, 1859 (Coleoptera, Hydrophilidae) from Northern Luzon, Philippines.

Two species of Anacaena Thomson, 1859, A.angatbuhay sp. nov. and A.auxilium sp. nov., are described from Northern Luzon, Philippines. The new species can be distinguished through colour, body shape, surface puncturation and characteristic aedeagi. Descriptions are provided and complemented with habitus photographs and drawings of the aedeagi. Data on genus distribution in the Philippines are reviewed and an updated Philippine checklist is provided.

Two new species of Byrrhinus Motschulsky, 1858 (Coleoptera, Limnichidae, Limnichinae) from Negros, Philippines.

Two new species of Limnichidae beetles, Byrrhinusnegrosensis sp. nov. and Byrrhinusvillarini sp. nov., are described from the Island of Negros in the Philippines. The adult specimens of the new species can be differentiated by patterns of body punctation, colour and orientation of elytral pubescence, posterolateral angle of pronotum, tarsomere length ratio and aedeagal form. Two clades, representing the two new species, were retrieved in the Maximum Likelihood gene tree using the 3'-end of the COI gene. Maximum genetic divergence within B.negrosensis sp. nov. and B.villarini sp. nov. were recorded to be 2.3% and 1.3%, respectively, while the mean interspecific divergence between the two new species was 19.7%. Morphological descriptions, digital photographs and COI sequences were provided for the two species. The state of knowledge of Byrrhinus is reviewed and an updated Philippine checklist is provided. By coupling morphological and molecular data, this paper provides the first additional new species of Philippine Byrrhinus in the last 28 years.

Hydraena (s.str.) dinarica, new species (Coleoptera: Hydraenidae) along with further records of Hydraena spp. from Durmitor National Park, Montenegro and comments on the DNA barcoding problem with the genus.

BACKGROUND: Long-palped Water Beetles were collected during a taxon expedition in Montenegro which involved citizen scientists, students and taxonomists. The material was collected from springs, brooks, fens and the Tara River, at altitudes between 600 m and 1450 m above sea level, using fine-meshed hand-nets and by manual checking of submerged substrates. The morphological species delimitation was supplemented and congruent with mtDNA sequences mainly obtained in the field using the newly-developed MinION-based ONTrack pipeline. NEW INFORMATION: The new species Hydraena dinarica Freitag & de Vries, sp. n. from Durmitor Mt. is described, illustrated and compared in detail to closely-related congeners of the H. saga d'Orchymont, 1930/H. emarginata Rey, 1885 species complex. Five additional species and female specimens of two unidentified morphospecies of the genus were also recorded in the vicinity of Durmitor National Park. New records and the first DNA barcodes for Hydraena biltoni Jäch & Díaz, 2012 (endemic to Montenegro) and H. morio Kiesenwetter, 1849 are provided. Further records of H. nigrita Germar, 1824, H. minutissima Stephens, 1829, H. subintegra Ganglbauer, 1901 and females of two unidentified morphospecies are commented upon. The resulting inter- and intraspecific genetic distances and some observations of low or zero sequence divergence between recently-diverged species of Hydraena Kugelann, 1794 are briefly discussed.

Contributions to the knowledge of water bugs in Mindoro Island, Philippines, with a species checklist of Nepomorpha and Gerromorpha (Insecta, Hemiptera, Heteroptera).

BACKGROUND: This survey aims to provide an updated species checklist of aquatic and semi-aquatic bugs in the intra-Philippine biogeographic Region of Mindoro. An assessment survey of water bugs (Hemiptera, Heteroptera) was conducted mostly by manual collection in selected areas of Oriental Mindoro from 2017 to 2018, in which some of the collecting activities were undertaken by graduate students of Ateneo de Manila University. NEW INFORMATION: Twenty-nine aquatic and semi-aquatic heteropteran species were documented and some are known island-endemic species or subspecies, including Enithares martini mindoroensis Nieser & Zettel, 1999, Hydrotrephes stereoides mindoroensis Zettel, 2003, Aphelocheirus freitagi Zettel & Pangantihon, 2010, Rhagovelia mindoroensis Zettel, 1994, Rhagovelia raddai Zettel, 1994, Rhagovelia potamophila Zettel, 1996 and Strongylovelia mindoroensis Lansbury & Zettel, 1997, which were found in new areas in the Region. In addition, there are also new records for the Island that have already been documented in other parts of the Philippines, such as the Philippine-endemic Ochterus magnus Gapud & San Valentin, 1977 and Hebrus philippinus Zettel, 2006 and the widely-distributed backswimmers Anisops nigrolineatus Lundblad, 1933 and Anisops rhomboides Nieser & Chen, 1999. Several undescribed specimens and potentially new species are also discussed in this paper. Further surveys in the other parts of Mindoro and in the other regions of the Philippines, are encouraged to produce a comprehensive baseline data of heteropteran species richness in the country.

Description of Neoperla mindoroensis sp. nov., the first record of a stonefly from Mindoro, Philippines (Plecoptera, Perlidae), and identification of its life stages using COI barcodes.

The new stonefly species, Neoperla mindoroensis sp. nov. (Perlidae), from Mindoro island is described. The new species is assigned to the N. recta species complex of the N. montivaga group on account of its obvious T7 and T8 with pointed processes and the presence of basolateral lobes in the everted aedeagal sac. The male adult is distinguishable by its aedeagus with a slightly raised mediodorsal lobe, fully covered with fine spinules, while the female adult has comparably small eggs (240 × 220 µm) with a punctate, chorionic surface with punctae arranged in polygonal FCIs. The life stages and sexes were assigned using COI mtDNA barcodes (2.2% maximum intraspecific genetic distance), which were compared with available barcodes of congeners, which had interspecific genetic distances varying by at least 23.5%. Biogeographic aspects, ecological habitat requirements, and suitability as potential bioindicator of the species are also briefly discussed.

Ancyronyx clisteri, a new spider riffle beetle species from Borneo, redescription of A. sarawacensis Jäch including a description of the larva and new distribution data for A. procerus Jäch using DNA barcodes (Coleoptera, Elmidae).

Ancyronyx clisteri sp. nov. (Coleoptera, Elmidae) a new spider riffle beetle discovered from northern Borneo (Brunei; Sabah and Sarawak, Malaysia) and the larva of Ancyronyx sarawacensis Jäch are described. Illustrations of the habitus and diagnostic characters of the new species and the similar and highly variable A. sarawacensis are presented. Differences to closely related species, based on DNA barcodes and morphological characters, are discussed. Association of the larva and the imago of A. sarawacensis, and the occurrence of Ancyronyx procerus Jäch in Peninsular Malaysia and Sabah are confirmed by using COI mtDNA sequences.

Integrative taxonomy of the genus Dudgeodes Sartori, 2008 (Insecta, Ephemeroptera, Teloganodidae) from the Philippines with description of new species and supplementary descriptions of Southeast Asian species.

COI sequences were used as an initial clustering method to delimit putative species of the genus Dudgeodes in the Philippines. An overview of the diagnostic characters of Philippine species and characters with high intraspecific variability are given. Six new species of Dudgeodes are described and illustrated: D. bauernfeindi Garces & Sartori, sp. nov., D. freitagi Garces & Sartori, sp. nov., D. luntian Garces & Sartori, sp. nov., D. pangantihoni Garces & Sartori, sp. nov., D. tabang Garces & Sartori, sp. nov., and D. vonrinteleni Garces & Sartori, sp. nov., all known from the nymphal stage. Supplementary descriptions are provided for D. pescadori Sartori, 2008, D. hutanis Sartori, 2008, D. stephani Sartori, 2008, D. ulmeri Sartori, 2008, and D. celebensis Sartori, 2008. A key to the nymphs of Philippine Dudgeodes species is proposed.

Ancyronyx lianlabangorum sp. nov., a new spider riffle beetle from Sarawak, and new distribution records for A. pulcherrimus Kodada, Jäch & Ciampor based on DNA barcodes (Coleoptera, Elmidae).

Ancyronyx lianlabangorum sp. nov. (Coleoptera, Elmidae), a new spider riffle beetle from the Kelabit Highlands (Sarawak, northern Borneo), is described. Illustrations of the habitus and diagnostic characters of the new species and the similar, polymorphic A. pulcherrimus Kodada et al. are presented. Differences to closely related species, based on COI nucleotide sequences and morphological characters, are discussed. Ancyronyx pulcherrimus is here recorded from Sarawak for the first time, based on DNA barcoding.

A Rapid and Accurate MinION-Based Workflow for Tracking Species Biodiversity in the Field.

Genetic markers (DNA barcodes) are often used to support and confirm species identification. Barcode sequences can be generated in the field using portable systems based on the Oxford Nanopore Technologies (ONT) MinION sequencer. However, to achieve a broader application, current proof-of-principle workflows for on-site barcoding analysis must be standardized to ensure a reliable and robust performance under suboptimal field conditions without increasing costs. Here, we demonstrate the implementation of a new on-site workflow for DNA extraction, PCR-based barcoding, and the generation of consensus sequences. The portable laboratory features inexpensive instruments that can be carried as hand luggage and uses standard molecular biology protocols and reagents that tolerate adverse environmental conditions. Barcodes are sequenced using MinION technology and analyzed with ONTrack, an original de novo assembly pipeline that requires as few as 1000 reads per sample. ONTrack-derived consensus barcodes have a high accuracy, ranging from 99.8 to 100%, despite the presence of homopolymer runs. The ONTrack pipeline has a user-friendly interface and returns consensus sequences in minutes. The remarkable accuracy and low computational demand of the ONTrack pipeline, together with the inexpensive equipment and simple protocols, make the proposed workflow particularly suitable for tracking species under field conditions.

Sparsorythussescarorum, new species from Mindoro, Philippines (Ephemeroptera, Tricorythidae).

A new mayfly species, Sparsorythussescarorum sp. n. (Tricorythidae) is described from Mindoro Island, Philippines. Nymphs are characterized by the combination of the following characters: compound eyes of approximately equal size in both sexes, shape and setation of legs, presence of rudimentary gills on abdominal segment VII, and some details of mouthparts. Male imagines are characterized by the coloration pattern of wings and details of genitalia. The developmental stages are matched by DNA barcodes.

Three new species of Grouvellinus Champion, 1923 from Maliau Basin, Sabah, Borneo, discovered by citizen scientists during the first Taxon Expedition (Insecta, Coleoptera, Elmidae).

Further results are presented of the first field course at Maliau Basin, Malaysian Borneo organized by Taxon Expeditions, an organization which enables citizen scientists to be directly involved in taxonomic discoveries. Three new species of the aquatic beetle genus Grouvellinus Champion, 1923, namely G. leonardodicaprioisp. n., G. andrekuipersisp. n., and G. questsp. n. were collected jointly by the citizen scientists and taxonomists during the fieldwork in Maliau Basin. Material was mainly sampled from sandstone bottom rocks of blackwater streams at altitudes between 900 m and 1,000 m using fine-meshed hand-nets. The genus is widely distributed in the Oriental and Palearctic regions, but these are the first records from the island of Borneo.

The complex evolutionary history and phylogeography of Caridina typus (Crustacea: Decapoda): long-distance dispersal and cryptic allopatric species.

The evolutionary history of the old, diverse freshwater shrimp genus Caridina is still poorly understood, despite its vast distribution - from Africa to Polynesia. Here, we used nuclear and mitochondrial DNA to infer the phylogeographic and evolutionary history of C. typus, which is one of only four species distributed across the entire range of the genus. Despite this species' potential for high levels of gene flow, questions have been raised regarding its phylogeographic structure and taxonomic status. We identified three distinct lineages that likely diverged in the Miocene. Molecular dating and ancestral range reconstructions are congruent with C. typus' early dispersal to Africa, possibly mediated by the Miocene Indian Ocean Equatorial Jet, followed by back dispersal to Australasia after the Jet's closure. Furthermore, several different species delimitation methods indicate each lineage represents a distinct (cryptic) species, contradicting current morphospecies delimitation of a single C. typus taxon. The evolutionary history of C. typus lineages is complex, in which ancient oceanic current systems and (currently unrecognised) speciation events preceded secondary sympatry of these cryptic species.

Vietelmis jablonskii, a new species of riffle beetle from Laos and Thailand and new faunistic records on Vietelmis Delève, 1968 from Malaysia (Coleoptera: Elmidae).

A new species of riffle beetle, Vietelmis jablonskii, from Laos and Thailand is described and illustrated. Differences to other Vietelmis species are discussed and an identification key for the Vietelmis is presented. New faunistic records are provided for V. kovaci Kodada & Ciampor, 2000; the genus Vietelmis is newly recorded for Thailand.

Hydraena (Hydraenopsis) ateneo, new species (Coleoptera, Hydraenidae) and other aquatic Polyphaga from a small habitat patch in a highly urbanized landscape of Metro Manila, Philippines.

Seven species of Hydraenidae, Hydrophilidae and Elmidae are recorded from temporary freshwater habitats at the Ateneo de Manila University Campus in the metropolitan area of Manila, Philippines. They were identified as Enochrus (Lumetus) fragiloides d'Orchymont, Helochares (Hydrobaticus) lepidus d'Orchymont, Helochares (Helochares) pallens (MacLeay), Hydraena (Hydraenopsis) scabra d'Orchymont, Hydraena (Hydraenopsis) palawanensis Freitag & Jäch (new record for Luzon Island), Stenelmis sp. A further hydraenid species was unknown to science and is newly described: Hydraena (Hydraenopsis) ateneo Freitag, sp. n. Aedeagus, gonocoxite, spermatheca, and female tergite X are illustrated by computer-based line drawings. Habitus images of all three Hydraena Kugelann species recorded and a checklist of the Philippine Hydraena are provided. The presence of these seven species in the Ateneo campus is briefly discussed in regard to the area's history. Measures to maintain and extend semi-natural islands of biodiversity in urban areas are suggested.

Ancyronyx Erichson, 1847 (Coleoptera, Elmidae) from Mindoro, Philippines, with description of the larvae and two new species using DNA sequences for the assignment of the developmental stages.

Ancyronyx buhid sp. n. and Ancyronyx tamaraw sp. n. are described based on adults and larvae, matched using their cox1 or cob DNA sequence data. Additional records of Ancyronyx schillhammeri Jäch, 1994 and Ancyronyx minerva Freitag & Jäch, 2007 from Mindoro are listed. The previously unknown larva of Ancyronyx schillhammeri is also described here, aided by cox1 data. The new species and larval stages are described in detail and illustrated by SEM and stacked microscopic images. Keys to the adult and larval Ancyronyx species of Mindoro and an updated checklist of Philippine Ancyronyx species are provided. The usefulness as bioindicators, the phylogenetic relationships and biogeographic aspects affecting the distribution patterns are briefly discussed.

Larvae and a new species of Ancyronyx Erichson, 1847 (Insecta, Coleoptera, Elmidae) from Palawan, Philippines, using DNA sequences for the assignment of the developmental stages.

Ancyronyx montanussp. n. is described based on adults and larvae, matched using their cox1 DNA sequence data. Larvae of six additional species of Ancyronyx Erichson, 1847 were also described here for the first time, aided by cox1 or cob data: Ancyronyx helgeschneideri Freitag & Jäch, 2007, Ancyronyx minerva Freitag & Jäch, 2007, Ancyronyx patrolus Freitag & Jäch, 2007, Ancyronyx procerus Jäch, 1994, Ancyronyx punkti Freitag & Jäch, 2007, Ancyronyx pseudopatrolus Freitag & Jäch, 2007. Ancyronyx procerus is newly recorded from the Philippines by a larval specimen from Busuanga island. The new species and larval stages are described in detail and illustrated by digital and SEM images. A key to the Ancyronyx larvae of Palawan and an updated checklist of Philippine Ancyronyx is provided.