New species of Papuanatula Lugo-Ortiz & McCafferty, 1999 from New Guinea (Ephemeroptera, Baetidae) with focus on Batanta Island

1 New species of Papuanatula Lugo-Ortiz & McCafferty, 1999 from New Guinea (Ephemeroptera, Baetidae) with focus on Batanta Island Thomas Kaltenbach1,2 , Tibor Kovács3, Jean-Luc Gattolliat1,2 1 Muséum cantonal des Sciences Naturelles, Département de zoologie, Palais de Rumine, Place Riponne 6, CH-1005 Lausanne, Switzerland 2 University of Lausanne (UNIL), Department of Ecology and Evolution, CH-1015 Lausanne, Switzerland 3 Mátra Museum of the Hungarian Natural History Museum of the Hungarian National Museum Public Collection Centre, Kossuth Lajos u. 40, H-3200 Gyöngyös, Hungary Corresponding author: Thomas Kaltenbach ([email protected]) Copyright: © Thomas Kaltenbach et al. This is an open access article distributed under terms of the Creative Commons Attribution License (Attribution 4.0 International – CC BY 4.0). Research Article Abstract Since 2010, the Mátra Museum of the Hungarian Natural History Museum has conducted a long-term research program to explore the biodiversity and collect data of selected groups of insects and partly other animals on the island of Batanta (Indonesia, West Papua). During this research project, numerous mayflies of different stages were collected as well. In this study, mayflies of the highly diverse genus Papuanatula (Ephemeroptera, Baetidae) collected in Batanta between 2014 and 2025 were investigated. Six new species were discovered, four belonging to the subgenus Papuanatula s. str., P. batantaraja sp. nov., P. cukiclara sp. nov., P. cataracta sp. nov., P. batanlenos sp. nov., and two to the subgenus Papuafiliola, P. horvathrobi sp. nov. and P. longabranchias sp. nov. Their larval stages are described and illustrated. Additionally, imagos and subimagos of two of the new species are described as well, and the eggs of one species. Furthermore, a new species of Papuanatula from another region of New Guinea is described. For most species, the species delimitation is also supported by mitochondrial DNA data (COI). Keys to the larvae of all species per subgenus or species group relevant for Batanta are presented. The total number of Papuanatula species is augmented to 33. Key words: COI, eggs, imago, Papuafiliola, subimago, West Papua Introduction Currently, the Mátra Museum of the Hungarian Natural History Museum in collaboration with other research organizations is running a research program on the biodiversity of Batanta Island (Indonesia, New Guinea, West Papua). Covering an area of approximately 450 km2, Batanta is a small island largely covered by tropical lowland rainforest, with rich and undisturbed forest streams, its highest point is 1184 m (for details see Kovács et al. 2015). The research program is primarily focused on various insect groups; it started in 2010 and is planned to continue for several more years. From 2014, every year a research group (including one of us, TiKo) has been conducting several weeks collecting and observation campaigns in various parts of Batanta, with the support of locals. Since the beginning of this program, a number of articles Academic editor: Ben Price Received: 11 August 2025 Accepted: 25 September 2025 Published: 10 November 2025 ZooBank: https://zoobank. org/2A99E3EF-D053-481C-A087F5058972DC96 Citation: Kaltenbach T, Kovács T, Gattolliat J-L (2025) New species of Papuanatula Lugo-Ortiz & McCafferty, 1999 from New Guinea (Ephemeroptera, Baetidae) with focus on Batanta Island. ZooKeys 1259: 1–55. https://doi.org/10.3897/ zookeys.1259.168419 ZooKeys 1259: 1–55 (2025) DOI: 10.3897/zookeys.1259.168419 2 ZooKeys 1259: 1–55 (2025), DOI: 10.3897/zookeys.1259.168419 Thomas Kaltenbach et al.: New species of Papuanatula from New Guinea presenting results from different research fields have been published: Odonata, with one species known before, 64 species were recorded by Kovács and Theischinger (2023), including seven species new to science, and three additional new species will be described in another article (Kovács and Theischinger in preparation); Trichoptera, with no known species, 11 articles were published with data on 163 species of which 157 were described as new species (Kovács et al. 2025). Other groups were studied as well, such as epiphyllous liverworts (Marchantiophyta), for which no data were available before, 48 taxa were found, including a new species and a new subspecies (Pócs and Kovács 2023); earthworms (Megadrili: Acanthodrilidae, Megascolecidae), for which no data were available before, five species were identified (Szederjesi 2019); Gastropoda (Cyclophoroidea, Pupinidae), Varga and Páll-Gergely (2017) described Bellardiella kovacsi as a new species; most recently, the distribution and behaviour of Wilson’s bird-of-paradise (Diphyllodes respublica) was reported by Horváth et al. (2024). In the present study, we examine the material of the highly diverse genus Papuanatula Lugo-Ortiz & McCafferty, 1999 (Ephemeroptera, Baetidae) collected between 2014 and 2025 in Batanta. Presently, Papuanatula is divided in two subgenera, Papuanatula s. str. and Papuafiliola Kaltenbach, Kluge & Gattolliat, 2025. Further, Papuanatula s. str. is consisting of five species groups defined in Kaltenbach et al. (2025). We recorded six different species of Papuanatula in Batanta, four belonging to the subgenus Papuanatula s. str. and two to the subgenus Papuafiliola, all of them being new to science. They are described and illustrated mainly based on larvae, but partly also based on imagos, subimagos and eggs. Species delimitation is mostly supported by mitochondrial DNA data (COI) as well. Additionally, we describe a new species of Papuanatula from another part of New Guinea. Presently, the genus Papuanatula is known to have a disjunct distribution with one species on Sulawesi Island, 24 species on New Guinea, and one species on New Britain (Demoulin 1969; Lugo-Ortiz and McCafferty 1999; Kaltenbach et al. 2025). This study brings the total number of known Papuanatula species to 33. The mayfly fauna of New Guinea, the second largest island of the world after Greenland, is astonishingly poor in number of families and genera. Only five of ~40 families and 13 of ~460 genera worldwide are present (Jacobus et al. 2019; Kluge 2025). From Baetidae, the most diverse family with nearly one third of all mayfly species, only five of ~115 genera have been discovered so far in New Guinea (Centroptella Braasch & Soldán, 1980, Cloeon Leach, 1815, Labiobaetis Novikova & Kluge, 1987, Mystaxiops McCafferty & Sun, 2005, and Papuanatula Lugo-Ortiz & McCafferty, 1999). However, two of these genera were able to develop a remarkable diversity, Labiobaetis with 43 species (Lugo-Ortiz et al. 1999; Kaltenbach and Gattolliat 2018, 2021; Kaltenbach et al. 2021, 2023), and Papuanatula with now 33 species (Kaltenbach et al. 2025). A second example of megadiversity in New Guinea mayflies is the family Leptophlebiidae, based on the tribe Thraulini (Sartori and Salles 2025). Given the results of repeated collection efforts in Batanta, it is likely that many more species of Papuanatula will be discovered in mainland New Guinea and nearby islands in the near future. 3 ZooKeys 1259: 1–55 (2025), DOI: 10.3897/zookeys.1259.168419 Thomas Kaltenbach et al.: New species of Papuanatula from New Guinea Materials and methods Most material was collected by one of us (TiKo) on the island of Batanta (Indonesia, West Papua) together with colleagues and a local team during several trips from 2014–2025. The larvae were collected by kick-sampling and preserved in 70%–96% ethanol, winged stages were attracted by light (Xenon HDI bulb, 35 Watt, 6000 Kelvin) in or close to the riverbed and also preserved in 70%–96% ethanol. Later, assignment of winged stages to a species was done by molecular analysis of COI. Eggs of one species were extracted from female subimagos. The dissection of specimens was done in Cellosolve (2-Ethoxyethanol) with subsequent mounting on slides with Euparal liquid, using an Olympus SZX7 stereomicroscope. DNA of part of the specimens was extracted using non-destructive methods allowing subsequent morphological analysis (see Vuataz et al. 2011 for details). We amplified a 658 bp fragment of the mitochondrial gene cytochrome oxidase subunit 1 (COI) using the primers LCO 1490 and HCO 2198 (Folmer et al. 1994). Sequencing was done with Sanger’s method (Sanger et al. 1977). The genetic variability between specimens was estimated using Kimura-2-parameter distances (K2P, Kimura 1980), calculated with the program MEGA 11 (Tamura et al. 2021, http:// www.megasoftware.net). The GenBank accession numbers are given in Table 1. Table 1. Sequenced specimens. Species Specimen voucher catalogue # Stage GPS coordinates GenBank # (COI) GenSeq Nomenclature P. batantaraja sp. nov. GBIFCH00975888 L00°52'16"S, 130°37'46"E PX098278 genseq-2 COI P. batanlenos sp. nov. GBIFCH00975880 L00°52'31"S, 130°37'58"E PX098287 genseq-2 COI GBIFCH00975879 L00°52'31"S, 130°37'58"E PX098286 genseq-2 COI GBIFCH00975875 L00°54'21"S, 130°38'32"E PX098285 genseq-2 COI GBIFCH00975864 SI 00°52'31"S, 130°37'58"E PX098284 genseq-2 COI GBIFCH00975967 I00°52'49"S, 130°38'05"E PX098279 genseq-2 COI GBIFCH00975966 SI 00°52'49"S, 130°38'05"E PX098280 genseq-2 COI GBIFCH00975969 SI 00°53'03"S, 130°38'13"E PX098281 genseq-2 COI GBIFCH00975962 SI 00°53'22"S, 130°39'07"E PX098283 genseq-2 COI GBIFCH00975960 SI 00°53'07"S, 130°38'59"E PX098282 genseq-2 COI P. longabranchias sp. nov. GBIFCH00975884 L00°52'31"S, 130°37'58"E PX098297 genseq-2 COI GBIFCH00975811 I00°53'03"S, 130°38'13"E PX098288 genseq-2 COI GBIFCH00975940 I00°53'03"S, 130°38'13"E PX098289 genseq-2 COI GBIFCH00975943 SI 00°53'03"S, 130°38'13"E PX098291 genseq-2 COI GBIFCH00975942 SI 00°53'03"S, 130°38'13"E PX098290 genseq-2 COI GBIFCH00975954 SI 00°53'43"S, 130°36'39"E PX098296 genseq-2 COI GBIFCH00975953 SI 00°53'43"S, 130°36'39"E PX098295 genseq-2 COI GBIFCH00975951 SI 00°52'49"S, 130°38'05"E PX098294 genseq-2 COI GBIFCH00975950 SI 00°52'49"S, 130°38'05"E PX098293 genseq-2 COI GBIFCH00975946 SI 00°53'43"S, 130°36'39"E PX098292 genseq-2 COI P. arfak sp. nov. GBIFCH00975788 L01°06'35"S, 133°56'51"E PX098298 genseq-2 COI P. cukiclara sp. nov. GBIFCH01582008 L00°53'03"S, 130°38'13"E PX098299 genseq-2 COI GBIFCH01582009 L00°52'27"S, 130°37'52"E PX098300 genseq-2 COI GBIFCH01582010 L00°52'27"S, 130°37'52"E PX098301 genseq-2 COI 4 ZooKeys 1259: 1–55 (2025), DOI: 10.3897/zookeys.1259.168419 Thomas Kaltenbach et al.: New species of Papuanatula from New Guinea Photographs of larvae in toto were taken using a Canon EOS 6D camera and processed with the programs Adobe Photoshop Lightroom (http://www. adobe.com) and Helicon Focus v. 5.3 (http://www.heliconsoft.com). Pictures of larval, subimaginal and imaginal structures were taken with an Olympus SC 50 camera on an Olympus BX43 microscope, processed with the program Olympus Cell Sense v. 3.2., and in addition with a Keyence Photomicroscope. SEM pictures were taken using a FEI Quanta FEC 250 electron microscope (Thermo Fisher). Photographs were subsequently enhanced with Adobe Photoshop Elements 13. The distribution map was created with the program SimpleMappr (Shorthouse 2010). The dichotomous keys were elaborated with the support of the program DKey v. 1.3.0 (http://drawwing.org/dkey, Tofilski 2018). The terminology follows Kluge (2004). The term “blank” is used to describe an unpigmented area of cuticle (Kluge et al. 2023). The term “posterior seta/setae” is used for long setae in posterior position of the claw (approximately opposite to the distalmost denticle), as proposed by Kluge and Novikova (2014). The term “microlepides“ is used according to Kluge (2022). Abbreviations MM Mátra Museum of the Hungarian Natural History Museum of the Hungarian National Museum Public Collection Centre, Gyöngyös (Hungary); MZB Museum Zoologicum Bogoriense (Indonesia); MZL Naturéum, Muséum cantonal des Sciences Naturelles, Lausanne (Switzerland). Results Subgenus Papuanatula Figs 1–19 Diagnosis (larval characters; according to Kaltenbach et al. 2025: 166). Antennal flagellum distally with brown dots; labrum wide, widest in medial area, dorsally with submarginal row of long, feathered setae (Fig. 2b); both mandibles with incisor strongly elongated, blade-like (Fig. 7c, d; full-length incisors present only at the beginning of each instar, mostly worn at the end of instar); labial palp without clear distomedial projection at segment II (Fig. 2e); outer side of femur usually with single regular row of long, hair-like setae bearing numerous fine, short branches on all sides (Fig. 8a, b); anterior side of tibia usually with regular row of setae similar to that on femur (Fig. 8a). Papuanatula bessa species group (Kaltenbach et al. 2025) Diagnosis (larval characters). Body dorsally with irregular row of long, fine, soft setae on midline (Figs 1b, 5a); abdominal terga partially with paired, medioposterior humps or elevations (Kaltenbach et al. 2025: fig. 5a–e). 5 ZooKeys 1259: 1–55 (2025), DOI: 10.3897/zookeys.1259.168419 Thomas Kaltenbach et al.: New species of Papuanatula from New Guinea Papuanatula (Papuanatula) arfak Kaltenbach, Kovács & Gattolliat, sp. nov. https://zoobank.org/AC95E18D-EFBD-4CE1-B3C7-23F9F0DFBC7C Figs 1–5 Type material. Holotype. Indonesia • larva; New Guinea, Papua Prov., Riv. Je, Loc. Arfak, E of Amber village; 01°06'35"S, 133°56'51"E; 1200 m; 16.vi.2016; leg. B. Sumoked and M. Balke; (BH68); on slide; GBIFCH00592543; MZB. Paratypes. 24 larvae; same data as holotype; 4 on slides; GBIFCH00975788, GBIFCH00975789, GBIFCH00592534, GBIFCH00592540, GBIFCH01221764; MZL; 20 in alcohol; GBIFCH00975790, GBIFCH00976060, GBIFCH00976063, GBIFCH00976111; MZL. Diagnosis. Larva. The following combination of characters distinguishes P. arfak sp. nov. from other species of Papuanatula s. str.: body dorsally with irregular row of long, fine, simple setae along midline; abdominal terga without distinct protuberances; abdominal terga I–VI with hypodermal wide dark brown transverse band close to anterior margin, I–IX with medial narrow, dark brown, longitudinal streak; femur proximally with wedge-shaped blank; abdominal terga with triangular, apically rounded denticles on posterior margin; small scattered scales on abdominal terga oblong, striated, apically denticulate; paracercus with nine segments. Description. Larva (Figs 1–5). Body length 4.5–5.7 mm, cerci much longer than body length (~ 1.4×). Cuticular coloration (Figs 1a–c, 3a). Head, thorax and abdomen dorsally brown; thorax with indistinct, complex pattern. Femur proximally with wedgeshaped blank, surrounded by grey area, distally yellow-brown to grey-brown; tibia grey; tarsus grey-brown, distally darker. Head, thorax and abdominal segment I ventrally ecru, protuberances of thoracic sterna brown; abdominal segments II–X ventrally brown, laterally paler. Cerci yellow-brown. Hypodermal coloration (Fig. 1a). Abdominal terga I–VI (VII) with wide dark brown transverse band close to anterior margin, I–IX with narrow dark brown transverse band close to posterior margin and medially narrow dark brown, longitudinal streak. Head (Figs 1b, 3h). Dorsally with irregular row of long, fine, simple setae along midline. Antenna. Length ~1.5× head length. As typical for subgenus. Developing turbinate eyes in last instar male larva (Fig. 3h) large, subquadrangular, touching each other in the middle. Labrum (Fig. 2a, b). Length 0.5× maximum width, laterally convex. Dorsal, sub-marginal arc with ~ 30 feathered setae. Right mandible (Fig. 2c). Margin between prostheca and mola straight, with row of minute denticles. Otherwise, as typical for subgenus. Left mandible (Fig. 2d). Margin between prostheca and mola straight, with row of minute denticles. Otherwise, as typical for subgenus. Hypopharynx (Fig. 2f). As typical for genus. Maxilla (Fig. 2g, h). Maxillary palp subequal in length to galea-lacinia; palp segment II slightly longer than segment I. Otherwise, as typical for the genus. Labium (Fig. 2e). Paraglossa dorsally with two spine-like setae near inner, distolateral margin. Labial palp with segment I subequal in length to segments II and 6 ZooKeys 1259: 1–55 (2025), DOI: 10.3897/zookeys.1259.168419 Thomas Kaltenbach et al.: New species of Papuanatula from New Guinea Figure 1. Papuanatula (Papuanatula) arfak sp. nov., larva, habitus. a. Dorsal view; b. Lateral view; c. Ventral view. Scale bars: 1 mm. 7 ZooKeys 1259: 1–55 (2025), DOI: 10.3897/zookeys.1259.168419 Thomas Kaltenbach et al.: New species of Papuanatula from New Guinea Figure 2. Papuanatula (Papuanatula) arfak sp. nov., larva. a. Labrum; b. Labrum, submarginal arc of setae; c. Right mandible; d. Left mandible; e. Labium; f. Hypopharynx and superlinguae; g. Maxilla; h. Maxillary palp; i. Developing subimaginal gonostyli. Scale bars: 50 µm (e), 20 µm (a, c, d, f, g, i),10 µm (b, h). 8 ZooKeys 1259: 1–55 (2025), DOI: 10.3897/zookeys.1259.168419 Thomas Kaltenbach et al.: New species of Papuanatula from New Guinea Figure 3. Papuanatula (Papuanatula) arfak sp. nov., larva. a. Middle leg; b. Fore tarsus; c. Fore claw; d. Fore femur, posterior apex; e. Fore tibia, posterior surface; f. Middle tibia, inner margin; g. Fore femur, ventral margin; h. Head, mature male larva. Scale bars: 100 µm (h), 50 µm (a), 20 µm (b), 10 µm (c–g). 9 ZooKeys 1259: 1–55 (2025), DOI: 10.3897/zookeys.1259.168419 Thomas Kaltenbach et al.: New species of Papuanatula from New Guinea Figure 4. Papuanatula (Papuanatula) arfak sp. nov., larva. a. Abdominal terga, posterior margins; b. Paracercus; c. Cercus, basal part; d. Cercus, distal part; e, f. Tergalius IV; g–i. Paraproct. Scale bars: 50 µm (h), 20 µm (a, b, g), 10 µm (c, d, f, h, i). 16 ZooKeys 1259: 1–55 (2025), DOI: 10.3897/zookeys.1259.168419 Thomas Kaltenbach et al.: New species of Papuanatula from New Guinea Figure 8. Papuanatula (Papuanatula) batantaraja sp. nov., larva. a. Hind leg; b. Hind femur, outer margin; c. Hind femur, surface; d. Hind tarsus, claw (arrow: posterior seta); e. Abdomen (arrow: protuberance on fore protoptera); f. Abdominal tergum V, surface; g. Abdominal terga; h. Paracercus; i. Cercus; j. Paraproct. Scale bars: 100 µm (e), 50 µm (a), 20 µm (b, d, h, j), 10 µm (c, f, g, i). 17 ZooKeys 1259: 1–55 (2025), DOI: 10.3897/zookeys.1259.168419 Thomas Kaltenbach et al.: New species of Papuanatula from New Guinea terga III and IV combined, tergalius IV as long as terga V, VI and ⅓ VII combined, tergalius VII reaching beginning of tergum X. Paraproct (Fig. 8j). Posterior margin expanded, smooth. Caudalii (Fig. 8h, i) Cerci without swimming setae. Paracercus vestigial. Pose of subimaginal gonostyli under larval cuticle. Unknown. Subimago. Unknown. Imago. Unknown. Egg. Unknown. Biological aspects. The species is known from the highest watercourse of Batanta, the Kalijakut River system, on altitudes between 430 m and 545 m. The upper habitat (Fig. 29a, type locality) has volcanic bedrock, the side branch is very fast-flowing, the larvae live on the stones of the steep run. It co-occurs with larvae of P. batanlenos sp. nov. and P. cukiclara sp. nov. In the lower habitat (Fig. 29b), the species is living in fast flowing water on steep, calcareous surfaces, associated with P. cukiclara sp. nov. Etymology. The species name batantaraja refers to the Indonesian island Batanta, where the species was found, and the Indonesian word “raja” meaning king, because it is the largest species known in the genus Papuanatula. Distribution. New Guinea, Batanta Island (Fig. 30). Papuanatula (Papuanatula) cukiclara Kaltenbach, Kovács & Gattolliat, sp. nov. https://zoobank.org/BAA5E384-8100-45F4-8790-F4BB63B1F102 Figs 9–11 Type material. Holotype. Indonesia • larva; West Papua, Batanta Island, Kalijakut River; 00°52'27"S, 130°37'52"E; 420 m; 09.ii.2024; leg. T. Kovács; on slide; GBIFCH00975889; 2024-12, EPHTYP-4; MM. Paratypes. 9 larvae; partly same data as holotype; 20.ii.2025; leg. T. Kovács; 3 in alcohol; GBIFCH01582007, GBIFCH01582009, GBIFCH001582010; MZL; 6 in alcohol; 2025-18.a, EPHTYP-5; MM • 3 larvae; West Papua, Batanta Island, right side stream of Kalijakut River, side spring area; 00°52'27"S, 130°37'51"E; 432 m; 20.ii.2025; leg. T. Kovács; 1 in alcohol; GBIFCH01582006; MZL; 2 in alcohol; 2025-18.b, EPHTYP-6; MM • 4 larvae; West Papua, Batanta Island, right side stream of Kalijakut River; 00°52'15"S, 130°37'45"E; 545 m; 21.ii.2025; leg. T. Kovács; 1 on slide; GBIFCH01221838; 1 in alcohol; GBIFCH01582005; MZL; 2 in alcohol; 202519, EPHTYP-7; MM • 3 larvae; West Papua, Batanta Island, Kalijakut River; 00°53'03"S, 130°38'13"E; 182 m; 19.ii.2025; leg. T. Kovács; 1 on slide; GBIFCH01221837; 1 in alcohol; GBIFCH01582008; MZL; 1 in alcohol; 2025-17, EPHTYP-8; MM. Diagnosis. Larva. The following combination of characters distinguishes P. cukiclara sp. nov. from other species of Papuanatula s. str.: body dorsally without row of long, fine, simple setae along midline; metanotum and abdominal terga I–VIII posteromedially with conspicuous, long, pointed protuberance, slightly bent posteriad; femur anteriorly with irregular wedge-shaped blank in basal part, blank area in distal part, and blank streak along outer margin; paracercus with five or six segments. Description. Larva (Figs 9–11). Body length 2.7–3.9 mm, cerci ~ 2× body length. 18 ZooKeys 1259: 1–55 (2025), DOI: 10.3897/zookeys.1259.168419 Thomas Kaltenbach et al.: New species of Papuanatula from New Guinea Figure 9. Papuanatula (Papuanatula) cukiclara sp. nov., larva, habitus. a. Dorsal view; b. Lateral view; c. Ventral view. Scale bars: 1 mm. Cuticular coloration (Figs 9a–c, 11c). Head, thorax and abdomen dorsally pale brown; thorax with indistinct pattern; abdominal terga V, VI, and X dorsally and laterally brighter, terga III and IV laterally brighter. Head, thorax and 19 ZooKeys 1259: 1–55 (2025), DOI: 10.3897/zookeys.1259.168419 Thomas Kaltenbach et al.: New species of Papuanatula from New Guinea abdomen ventrally pale brown. Legs pale brown, femur anteriorly with irregular wedge-shaped blank in basal part, blank area in distal part, and blank streak along outer margin. Caudalii ecru. Hypodermal coloration (Fig. 9a, b). Abdominal terga with fine dark brown transverse band along posterior margins. Head. Antenna (Fig. 10i). Length ~1.5× head length. Flagellum distally with brown dots. Developing turbinate eyes in last instar male larva unknown. Labrum (Fig. 10a, b). Length ~ 0.5× maximum width, laterally convex. Dorsal, sub-marginal arc with ~ 22 feathered setae. Right mandible (Fig. 10d). Margin between prostheca and mola straight, smooth. Otherwise, as typical for the subgenus. Left mandible (Fig. 10c). Margin between prostheca and mola straight, smooth. Otherwise, as typical for the subgenus. Hypopharynx (Fig. 10f). As typical for the genus. Maxilla (Fig. 10g). Maxillary palp approx. as long as galea-lacinia; palp segment II approx. as long as segment I. Otherwise, as typical for the genus. Labium (Fig. 10e). Paraglossa dorsally with two spine-like setae near inner, distolateral margin. Labial palp with segment I 0.7× length of segments II and III combined. Segment II without distomedial protuberance, dorsally with row of four spine-like setae near outer, distolateral margin. Segment III slightly pentagonal, pointed, 0.8× length of segment II. Otherwise, as typical for the genus. Thorax. Sterna. Protuberances not developed. Terga (Figs 9a, 11c). Metanotum posteromedially with stout, pointed protuberance. Legs (Fig. 11a–c). Ratio of leg segments: fore leg 0.9:1.0:0.3:0.2, middle leg 1.0: 1.0: 0.3: 0.2, and hind leg 1.0:1.0:0.3:0.2. Femur. Length ~ 3× maximum width; surface rough, denticulate on brown areas. Claw with one row of seven or eight denticles, and one posterior seta. Otherwise, as typical for the subgenus. Abdomen. Terga (Figs 9a, b, 11h). Abdominal terga I–VIII posteromedially with conspicuous, long, pointed protuberance, slightly bent posteriad; Posterior margin of terga: I smooth, without spines, II–IX with short, rounded spines, apically carrying needle-like denticles. Tergalii (Fig. 10h). Present on terga II–VII. Oblique ovoid; tracheation poorly developed, pigmentation of tracheae limited to main trunk; margins smooth, with short, fine, simple setae. Tergalius II as long as abdominal terga III and IV combined, tergalius IV as long as terga V and VI combined, tergalius VII reaching middle of tergum IX. Paraproct (Fig. 11e). Posterior margin expanded, with minute denticles in distal part. Caudalii (Fig. 11f, g) Cerci without swimming setae. Paracercus with six segments. Pose of subimaginal gonostyli under larval cuticle. As typical for the subgenus (folding in “Labiobaetis”-type). Subimago. Unknown. Imago. Unknown. Egg. Unknown. Biological aspects. This species is known from the Kalijakut river system (Fig. 29a, b, d type locality), occurring at elevations of 180–545 m. The larvae 20 ZooKeys 1259: 1–55 (2025), DOI: 10.3897/zookeys.1259.168419 Thomas Kaltenbach et al.: New species of Papuanatula from New Guinea Figure 10. Papuanatula (Papuanatula) cukiclara sp. nov., larva. a. Labrum; b. Labrum, submarginal arc of setae; c. Left mandible; d. Right mandible; e. Labium; f. Hypopharynx and superlinguae; g. Maxilla; h. Tergalius IV; i. Head. Scale bars: 100 µm (i), 20 µm (a, c–g),10 µm (b, h). 21 ZooKeys 1259: 1–55 (2025), DOI: 10.3897/zookeys.1259.168419 Thomas Kaltenbach et al.: New species of Papuanatula from New Guinea Figure 11. Papuanatula (Papuanatula) cukiclara sp. nov., larva. a. Hind leg; b. Fore tarsus, claw; c. Fore femur, anterior surface (brown areas); d. Abdominal terga; e. Paraproct; f. Paracercus; g. Cercus; h. Abdomen. Scale bars: 100 µm (h), 50 µm (a), 20 µm (f), 10 µm (b–e, g). 22 ZooKeys 1259: 1–55 (2025), DOI: 10.3897/zookeys.1259.168419 Thomas Kaltenbach et al.: New species of Papuanatula from New Guinea co-occur with P. batanlenos sp. nov., P. batantaraja sp. nov., and P. longabranchias sp. nov. Etymology. The species name is composed of “cuki”, meaning cute in Hungarian, and “clara”, meaning “bright” in Latin. The latter refers to the bright colour of the larva, especially on parts of the abdomen. Distribution. New Guinea, Batanta Island (Fig. 30). Papuanatula (Papuanatula) cataracta Kaltenbach, Kovács & Gattolliat, sp. nov. https://zoobank.org/4039B519-414C-4439-80C2-9490D45FAADE Figs 12–14 Type material. Holotype. Indonesia • larva; West Papua, Batanta Island, Warikambon Stream, upper waterfall; 00°50'25"S, 130°42'32"E; 159 m; 12.ii.2020; leg. T. Kovács, R. Horváth and P. Juhász; on slide; GBIFCH00976003; 20205, EPHTYP-9; MM. Paratypes. 6 larvae; same data as holotype; 3 on slides; GBIFCH00976000, GBIFCH00976001, GBIFCH00976002; 3 in alcohol; GBIFCH00975900, GBIFCH00975997, GBIFCH00975998; MZL • 27 larvae; partly same data as holotype; 04.ii.2024; leg. T. Kovács; 20 in alcohol; GBIFCH00975869, GBIFCH00975870, GBIFCH00975871, GBIFCH00975872, GBIFCH00975873; MZL; 7 in alcohol; 2024-8, EPHTYP-10; MM. Diagnosis. Larva. The following combination of characters distinguishes P. cataracta sp. nov. from other species of Papuanatula s. str.: body dorsally without row of long, fine, simple setae along midline; metanotum and abdominal terga I–VIII posteromedially with cone-like, pointed protuberance, longest on terga III–V, small on VII and VIII; femur anteriorly with irregular blank in basal part; anterior surface of femur and abdominal terga covered with minute, pointed spines; paracercus with five segments. Description. Larva (Figs 12–14). Body length 2.5–3.4 mm, cerci ~ 1.6× as long as body length. Cuticular coloration (Figs 12a–d, 14c). Head, thorax and abdomen dorsally pale brown. Head, thorax and abdomen ventrally pale brown. Legs pale brown, femur anteriorly with irregular blank areas in basal and distal part. Caudalii pale brown. Hypodermal coloration (Fig. 12a). Abdominal terga with narrow dark brown, transverse band along posterior margins. Head. Antenna (Fig. 13i). Length ~1.5× head length. Flagellum distally without brown dots. Developing turbinate eyes in last instar male larva (Fig. 13i) rather small, ovoid, widely spaced. Labrum (Fig. 13a, b). Length ~ 0.5× maximum width, laterally convex. Dorsal, sub-marginal arc with ~ 22 feathered setae. Right mandible (Fig. 13c). Margin between prostheca and mola straight, smooth. Otherwise, as typical for the subgenus. Left mandible (Fig. 13d). Subtriangular process poorly developed, transparent. Margin between prostheca and mola straight, smooth. Otherwise, as typical for the subgenus. Hypopharynx (Fig. 13f). As typical for the genus. Maxilla (Fig. 13g). Maxillary palp approx. as long as galea-lacinia; palp segment II ~ 1.3× as long as segment I. Otherwise, as typical for the genus. 23 ZooKeys 1259: 1–55 (2025), DOI: 10.3897/zookeys.1259.168419 Thomas Kaltenbach et al.: New species of Papuanatula from New Guinea Figure 12. Papuanatula (Papuanatula) cataracta sp. nov., larva, habitus. a. Dorsal view; b, c. Lateral view; d. Ventral view. Scale bars: 1 mm. 24 ZooKeys 1259: 1–55 (2025), DOI: 10.3897/zookeys.1259.168419 Thomas Kaltenbach et al.: New species of Papuanatula from New Guinea Figure 13. Papuanatula (Papuanatula) cataracta sp. nov., larva. a. Labrum; b. Labrum, submarginal arc of setae; c. Right mandible; d. Left mandible; e. Labium; f. Hypopharynx and superlinguae; g. Maxilla; h. Tergalius IV; i. Head. Scale bars: 100 µm (i), 20 µm (a, c–g),10 µm (b, h). 25 ZooKeys 1259: 1–55 (2025), DOI: 10.3897/zookeys.1259.168419 Thomas Kaltenbach et al.: New species of Papuanatula from New Guinea Figure 14. Papuanatula (Papuanatula) cataracta sp. nov., larva. a. Hind leg; b. Hind tarsus and claw; c. Abdomen; d. Abdominal tergum V; e. Abdominal terga V and VI; f. Cercus; g. Paracercus; h. Paraproct; i. Hind femur, surface. Scale bars: 50 µm (a, c), 10 µm (b, d–i). 32 ZooKeys 1259: 1–55 (2025), DOI: 10.3897/zookeys.1259.168419 Thomas Kaltenbach et al.: New species of Papuanatula from New Guinea Figure 17. Papuanatula (Papuanatula) batanlenos sp. nov., larva. a. Middle leg; b. Middle femur, outer margin; c. Middle tarsus, outer margin; d. Middle claw; e. Abdomen; f. Abdominal terga; g. Paraproct; h. Paracercus; i. Cercus. Scale bars: 100 µm (a, e), 20 µm (h), 10 µm (b–d, f, g, i). 33 ZooKeys 1259: 1–55 (2025), DOI: 10.3897/zookeys.1259.168419 Thomas Kaltenbach et al.: New species of Papuanatula from New Guinea terga III, IV, and ¼ V combined, tergalius IV as long as terga V, VI and ⅓ VII combined, tergalius VII as long as terga VIII and ⅓ IX combined. Paraproct (Fig. 17g). Posterior margin without prolongation, smooth, without denticles. Caudalii (Fig. 17h, i). Cerci without swimming setae. Paracercus with 14–16 segments. Pose of subimaginal gonostyli under larval cuticle (Fig. 16k). Segment III conical. Otherwise, as typical for the subgenus. Subimago (Fig. 19b–f). Body length 4.2–4.5 mm. Turbinate eyes of male ochre. Thorax brown. Wing membrane colourless, veins pale yellow-brown, base of wings brown, microtrichia pale yellow-brown. Legs very pale brown; coxa with hypodermal, dark brown fleck; femur anteriorly with hypodermal, shoe-shaped, dark brown marking in basal ½; femur posteriorly with hypodermal, dark brown distal streak and fleck in basal ½. Abdomen yellow-brown; male with hypodermal, dark brown, trough-shaped marking on terga III, IV, VII, and VIII, and sublateral, oblique, dark brown streaks on terga II, V and VI; female with same hypodermal markings, but more diffuse; all terga of both sexes with hypodermal, narrow, transvers, dark brown band on posterior margin. Cerci colourless. Texture (Fig. 19e, f). On all legs of male and female subimagos, terminal tarsomere covered with pointed microlepides; other tarsomeres covered mostly with blunt microlepides, with pointed microlepides near apex. Imago, male (Figs 18a–d, 19a). Body length ~ 3.8 mm. Head and antennae pale brown. Turbinate eyes pale brown, wide, with facetted surfaces round. Thorax pale brown. Fore wing with membrane colourless, base of wings brownish. Pterostigma with three or four oblique crossveins, basal two crossveins nearly complete. Legs light brownish; coxa with hypodermal, dark brown fleck; femur anteriorly with hypodermal, shoe-shaped, dark brown marking in basal ½; femur posteriorly with hypodermal, dark brown distal streak and fleck in basal ½. Abdominal segments I and VII–X pale brown, II–VI transparent, giving a blueish impression; with hypodermal, dark brown, trough-shaped marking on terga III, IV, VII, and VIII, and sublateral, oblique, dark brown streaks on terga II, V, and VI. Cerci colourless. Genitalia (Fig. 18d). Unistyliger slightly widened apically, with lateral margin slightly concave. Gonostylus with segment I conical and separated from segment II by concavity. Segment II slightly wider in distal ½, bent inward. Terminal segment III narrower than segment II, ovoid, length ~ 1.5× maximal width. Penial bridge with poorly expressed membranous projection between unistyligers. Imago, female. Unknown. Egg. Unknown. Eggs extracted from female subimagos are undeveloped. Biological aspects. It is a common species in most riverine habitat types in Batanta, living in the northern and southern watercourses of the island: Kalijakut (Fig. 29a, d (type locality), f), Tanjung Lampu and Waridor (Fig. 29e) Rivers, and Wailebet Stream. It is found from small, high-falling mountain tributaries to the lower, flat sections of the largest rivers at altitudes between 32 m and 545 m. Apart from the extreme habitat of P. cataracta sp. nov., it co-occurs with all Papuanatula species living in Batanta: P. batantaraja sp. nov., P. cukiclara sp. nov., P. horvathrobi sp. nov., and P. longabranchias sp. nov. 34 ZooKeys 1259: 1–55 (2025), DOI: 10.3897/zookeys.1259.168419 Thomas Kaltenbach et al.: New species of Papuanatula from New Guinea Figure 18. Papuanatula (Papuanatula) batanlenos sp. nov, imago, male. a. Habitus, lateral view; b. Habitus, dorsal view; c. Middle leg; d. Genitalia. Scale bars: 1 mm (a, b), 100 µm (c), 50 µm (d). Etymology. The species name batanlenos refers to the type locality on Batanta island and its belonging to the lenos species group. Distribution. New Guinea, Batanta Island (Fig. 30). 35 ZooKeys 1259: 1–55 (2025), DOI: 10.3897/zookeys.1259.168419 Thomas Kaltenbach et al.: New species of Papuanatula from New Guinea Figure 19. Papuanatula (Papuanatula) batanlenos sp. nov. Imago, male. a. Fore wing. Subimagos. b. Habitus, male; c. Habitus, female; d. Middle leg; e. Fore tarsus; f. Middle tarsus. Scale bars: 1 mm (a–c), 100 µm (d), 20 µm (e), 10 µm (f). Key to the species of P. lenos species group from New Guinea (larvae) Based on Kaltenbach et al. 2025. 1 New Britain; femur anteriorly with large, brown, triangular macula ....P. vaisisi – New Guinea; femur anteriorly with macula other than triangular ..............2 36 ZooKeys 1259: 1–55 (2025), DOI: 10.3897/zookeys.1259.168419 Thomas Kaltenbach et al.: New species of Papuanatula from New Guinea 2(1) Femur anteriorly with dark brown, shoe-shaped macula inside large, proximal blank; hypopharynx apically with “paired” tufts of seta-like spines ...5 – Femur anteriorly with macula other than shoe-shaped in proximal ½; hypopharynx with usual, unpaired tuft of seta-like spines ..................................3 3(2) Femur anteriorly with brown, hypodermal streak in proximal ½; posterior margin of abdominal terga with heterogenous, sharply pointed denticles ...................................................................................................P. zebrata – Femur anteriorly with red-brown to dark brown or blackish, oblong to dropshaped hypodermal marking in mediodistal area; posterior margin of abdominal terga with regular, triangular denticles ..........................................4 4(3) Thorax dorsally without distinct markings; femur with row of short, spinelike setae on inner margin; tergalii margin smooth, with short, fine, simple setae .................................................................................................... P. lenos – Pronotum with large, dark brown marking medially on anterior margin, narrow dark brown band along posterior margin of pronotum and anterior margin of mesonotum; femur with many medium, spine-like setae along inner margin; tergalii margin with minute serration and short, fine, simple setae .............................................................................................P. paralenos 5(2) Abdomen with dark grey-brown, trough-like markings on terga IV, VII, and VIII, laterally with oblique streaks on terga III, V and VI; paracercus with 14–16 segments .........................................................P. batanlenos sp. nov. – Abdomen with dark brown, trough-like marking on tergum IV, laterally without distinct oblique streaks; paracercus with 10–12 segments ....P. heterochaeta Subgenus Papuafiliola Kaltenbach, Kluge & Gattolliat, 2025 Figs 20–28 Diagnosis (larval characters; see Kaltenbach et al. 2025: 318). Antennal flagellum distally without brown dots; labrum widest at base, dorsally with few submarginal, simple setae (Fig. 24b); both mandibles without prolonged, bladelike incisor (Fig. 24c, d); labial palp with distomedian projection on segment II (Fig. 24e); outer side of femur with regular row of long, slender, flattened, parallel-sided setae with blunt apex (Fig. 25a, b); tibia with regular row of similar setae (Fig. 25a, c); tarsus on inner margin with distalmost seta not longer or only slightly longer than other setae. Papuanatula (Papuafiliola) horvathrobi Kovács, Kaltenbach & Gattolliat, sp. nov. https://zoobank.org/CBB57F98-CF73-43AE-AD47-58D6D1D8F031 Figs 20–22 Type material. Holotype. Indonesia • larva; West Papua, Batanta Island, Waibin River; between 00°49'21"S, 130°45'57"E and 00°50'02"S, 130°45'25"E; 20 m–45 m; 05.ii.2024; leg. T. Kovács; on slide; GBIFCH00975876; 2024-9, EPHTYP-16; MM. Paratypes. 1 larva; same data as holotype; on slide; GBIFCH00975913; MZL • 1 larva; West Papua, Batanta Island, Warai Stream; between 00°50'51"S, 130°35'14"E and 00°51'12"S, 130°35'20"E; 225 m–315 m; 21.ii.2024; leg. T. Kovács; on slide; GBIFCH00975877; MZL • West Papua, Batanta Island, Waridor 37 ZooKeys 1259: 1–55 (2025), DOI: 10.3897/zookeys.1259.168419 Thomas Kaltenbach et al.: New species of Papuanatula from New Guinea River (shallow, rocky, fast-flowing); 00°52'06"S, 130°31'30"E; 32 m; 14.ii.2025; leg. T. Kovács; 4 in alcohol; GBIFCH01582003; MZL; 12 in alcohol; 2025-12, EPHTYP-17; MM. Diagnosis. Larva. The following combination of characters distinguishes P. horvathrobi sp. nov. from other species of Papuanatula (Papuafiliola): thorax and abdomen dorsally without protuberances; femur with large blank in posterior ⅔; femur and abdomen without brown hypodermal maculae; tergalii oblong; paracercus with 15 segments. Description. Larva (Fig. 20–22). Body length ~ 3.0 mm, cerci ~ 1.4× body length. Cuticular coloration (Figs 20a, b, 22a). Head, thorax, and abdomen dorsally brown. Head, thorax and abdomen ventrally beige. Legs brown, femur with large blank in posterior ⅔, and distally with small blank area. Caudalii light brown. Hypodermal coloration (Fig. 20a, b). Head, thorax, abdomen, and legs without hypodermal markings. Head. Antenna. Length ~ 2.5× head length. Otherwise, as typical for the subgenus. Developing turbinate eyes in last instar male larva (Figs 20a, 21j) large, roundish, with some distance to each other. Labrum (Fig. 21a, b). Length 0.6× maximal width. With reduced, submarginal arc of three long, simple setae. Otherwise, as typical for subgenus. Right mandible (Fig. 21d). Incisor with five denticles; kinetodontium with three denticles, inner lateral margin with row of small denticles, becoming smaller and finer toward base, and with row of short, fine setae; margin between prostheca and mola slightly convex, with few minute denticles. Otherwise, as typical for subgenus. Left mandible (Fig. 21c). Incisor with five denticles, kinetodontium with three denticles; margin between prostheca and subtriangular process straight, with minute denticles. Otherwise, as typical for subgenus. Hypopharynx (Fig. 21f) with well-developed tuft of long, spine-like setae. Otherwise, as typical for the genus. Maxilla (Fig. 21g). Maxillary palp slightly longer than galea-lacinia; segment I 1.4× length of segment II. Otherwise, as typical for the genus. Labium (Fig. 21e) Paraglossa dorsally with three spine-like setae near inner, distolateral margin. Labial palp with segment I 0.7× length of segments II and III combined. Segment II with narrow thumb-like distomedial protuberance, slightly bent distad, dorsally with one spine-like seta near outer, distolateral margin. Segment III oblique conical, apically rounded, approx. as long as segment II. Otherwise, as typical for the genus. Thorax. Sterna without protuberances. Terga. Without long setae on midline; without protuberance. Legs (Fig. 22a–d). Ratio of leg segments: fore leg 1.1:1.0:0.3:0.1, middle leg 1.2:1.0:0.3:0.1 and hind leg 1.5:1.0:0.4:0.2. Femur. Length ~ 3× maximum width. Surface of brown areas with minute denticles. Tarsus. With regular row of medium, apically rounded setae along outer margin. Claw with one row of 11 denticles; one posterior seta. Otherwise, as typical for subgenus. Abdomen. Terga (Fig. 22e, f, j). Abdominal terga without long setae on midline; abdominal terga without median or submedian elevations or protuberances; surface with minute denticles. Posterior margins of abdominal terga: I smooth, without denticles, II–IX with very small, triangular denticles. 38 ZooKeys 1259: 1–55 (2025), DOI: 10.3897/zookeys.1259.168419 Thomas Kaltenbach et al.: New species of Papuanatula from New Guinea Figure 20. Papuanatula (Papuafiliola) horvathrobi sp. nov., larva, habitus. a. Dorsal view; b. Lateral view; c. Ventral view. Scale bars: 1 mm. Tergalii (Fig. 21h, i). Present on terga II–VII, oblong; tracheation well-developed, pigmentation not reaching margins. Each tergalius with anal rib longer than costal rib; ribs with minute, irregularly situated denticles on dorsal side. 39 ZooKeys 1259: 1–55 (2025), DOI: 10.3897/zookeys.1259.168419 Thomas Kaltenbach et al.: New species of Papuanatula from New Guinea Figure 21. Papuanatula (Papuafiliola) horvathrobi sp. nov., larva. a. Labrum; b. Labrum, submarginal arc of setae; c. Left mandible; d. Right mandible; e. Labium; f. Hypopharynx and superlinguae; g. Maxilla; h, i. Tergalius V; j. Head. Scale bars: 50 µm (j), 20 µm (c–h), 10 µm (a, b, i). 40 ZooKeys 1259: 1–55 (2025), DOI: 10.3897/zookeys.1259.168419 Thomas Kaltenbach et al.: New species of Papuanatula from New Guinea Figure 22. Papuanatula (Papuafiliola) horvathrobi sp. nov., larva. a. Hind leg; b. Hind femur, outer margin; c. Hind tibia, anterior surface; d. Hind tarsus, outer margin; e. Abdomen; f. Abdominal terga; g. Paraproct and developing subimaginal gonostylus; h. Paracercus; i. Cercus; j. Abdominal tergum IV, surface. Scale bars: 100 µm (e), 50 µm (a), 20 µm (h), 10 µm (b–d, f, g, i). 41 ZooKeys 1259: 1–55 (2025), DOI: 10.3897/zookeys.1259.168419 Thomas Kaltenbach et al.: New species of Papuanatula from New Guinea Tergalius II as long as terga III and ⅔ IV combined, tergalius IV as long as terga V and ⅔ VI combined, tergalius VII as long as terga VIII and ⅔ IX combined. Paraproct (Fig. 22g) without posterior prolongation. Posterior margin with small denticles. Caudalii (Fig. 22h, i). Cerci without swimming setae. Paracercus with 15 segments. Pose of subimaginal gonostyli under larval cuticle unknown. Subimago. Unknown. Imago. Unknown. Egg. Unknown. Biological aspects. The species is known from three watercourses in the northern part of Batanta (Waibin River (type locality), Waridor River, and Warai Stream), at altitudes from 20–315 m. The largest numbers were collected at a ford of the Waridor River at an altitude of 32 m (Fig. 29e), where P. batanlenos sp. nov., was also present in large numbers. Etymology. The new species is dedicated to Róbert Horváth, a Hungarian ornithologist, who initiated and organized the Hungarian research program on Biodiversity in Batanta in 2010. Since then, he gave continuous support in various aspects of the ten research trips conducted to date. Distribution. New Guinea, Batanta Island (Fig. 30). Papuanatula (Papuafiliola) longabranchias Kaltenbach, Kovács & Gattolliat, sp. nov. https://zoobank.org/0AB4B115-0A8E-4B40-AF33-6997824F06C5 Figs 23–27 Type material. Holotype. Indonesia • larva; West Papua, Batanta Island, Kalijakut River; 00°52'27"S, 130°37'52"E; 420 m; 09.ii.2024; leg. T. Kovács; on slide; GBIFCH00975882; 2024-12, EPHTYP-18; MM. Paratypes. 2 larvae; same data as holotype; on slides; GBIFCH00975883, GBIFCH00975884; MZL • 3 ♂ imagos, 30 subimagos; West Papua, Batanta Island, valley of Kalijakut River; 00°53'03"S, 130°38'13"E; 182 m; 15.ii.2023; at light; leg. T. Kovács, R. Horváth, P. Juhász, K. Sauyai, R. Sauyai; 1 imago on slide, thorax in alcohol; GBIFCH01221781, GBIFCH00975811; 2 imagos in alcohol; GBIFCH00975939, GBIFCH00975940; 30 subimagos; 28 in alcohol; GBIFCH00975941 (13♂, 10♀), GBIFCH00975942 (♂), GBIFCH00975943 (♂), GBIFCH00975944 (2♂, 1♀); 2 on slides; GBIFCH01221833 (♀), GBIFCH01221834 (♂); MZL • 15 subimagos; West Papua, Batanta Island, valley of Tanjung Lampu River; 00°53'43"S, 130°36'39"E; 18.ii.2020; at light; leg. T. Kovács, R. Horváth, P. Juhász; in alcohol; GBIFCH00975952 (9♂, 4♀), GBIFCH00975953 (♂), GBIFCH00975954 (♂); MZL • 15 subimagos; West Papua, Batanta Island, valley of Kalijakut River; 00°52'49"S, 130°38'05"E; 232 m; 19.ii.2020; at light; leg. T. Kovács, R. Horváth, P. Juhász, K. Sauyai, R. Sauyai; in alcohol; GBIFCH00975948 (6♂, 6♀), GBIFCH00975949 (♂), GBIFCH00975950 (♂), GBIFCH00975951 (♂); MZL • 7 subimagos (4♂, 3♀); West Papua, Batanta Island, valley of Tanjung Lampu River; 00°53'43"S, 130°36'39"E; 175 m; 21.ii.2018; at light; leg. T. Kovács, R. Horváth, P. Juhász, K. Sauyai, R. Sauyai; in alcohol; GBIFCH00975945, GBIFCH00975946, GBIFCH00975947; MZL • 3 larvae; West Papua, Batanta Island, Kalijakut Riv- 48 ZooKeys 1259: 1–55 (2025), DOI: 10.3897/zookeys.1259.168419 Thomas Kaltenbach et al.: New species of Papuanatula from New Guinea Figure 27. Papuanatula (Papuafiliola) longabranchias sp. nov. Imago, male. a. Fore wing; b. Genitalia. Subimagos. c, d. Habitus, male (lateral view, dorsal view); e, f. Habitus, female (lateral view, dorsal view); g. Hind leg; h. Fore tarsus; i. Hind tarsus. Scale bars: 1 mm (c–f), 100 µm (a, g), 20 µm (b, h), 10 µm (i). 49 ZooKeys 1259: 1–55 (2025), DOI: 10.3897/zookeys.1259.168419 Thomas Kaltenbach et al.: New species of Papuanatula from New Guinea Figure 28. Papuanatula (Papuafiliola) longabranchias sp. nov. a–c. Eggs; d. Micropyle. Scale bars: 10 µm (a–c), 5 µm (d). Comparison. The larva of Papuanatula (Papuafiliola) longabranchias sp. nov. is hardly different from Papuanatula (Papuafiliola) stenophylla Kaltenbach, Kluge & Gattolliat, 2025: P. longabranchias sp. nov. with hypodermal marking on anterior side of femur shoe-shaped, usually longer than wide (Fig. 23d); no 50 ZooKeys 1259: 1–55 (2025), DOI: 10.3897/zookeys.1259.168419 Thomas Kaltenbach et al.: New species of Papuanatula from New Guinea Figure 29. Habitats: P. batantaraja sp. nov. (a. Type locality, b); P. cukiclara sp. nov. (a, b, d. Type locality); P. cataracta sp. nov. (c. type locality); P. batanlenos sp. nov. (a, d. Type locality, e, f); P. horvathrobi sp. nov. (e); P. longabranchias sp. nov. (d. Type locality, f). short, fine, simple setae on surface of abdominal tergites (Fig. 25h); paracercus with 17 or 18 segments (Fig. 25j). P. stenophylla with hypodermal marking on anterior side of femur usually like a band, wider than long; scattered short, fine, 51 ZooKeys 1259: 1–55 (2025), DOI: 10.3897/zookeys.1259.168419 Thomas Kaltenbach et al.: New species of Papuanatula from New Guinea Figure 30. Distribution of Papuanatula species: yellow dots: known species (Kaltenbach et al. 2025); orange dot: Papuanatula arfak sp. nov. (present study); red dots: species from Batanta – P. batantaraja sp. nov., P. cukiclara sp. nov., P. cataracta sp. nov., P. batanlenos sp. nov., P. horvathrobi sp. nov., P. longabranchias sp. nov. (present study). simple setae on surface of abdominal terga; paracercus with ~ 15 segments (Kaltenbach et al. 2025: figs 132a, b, 135d). However, male imagos are clearly different: P. longabranchias sp. nov. has pale brown turbinate eyes (Fig. 26a, b), whereas P. stenophylla has dull-red turbinate eyes (Kaltenbach et al. 2025: fig. 137a, d). The eggs of both species are identical (Fig. 28a–d; Kaltenbach et al. 2025: fig. 138a). Biological aspects. The species is known from two watercourses in southern Batanta: Kalijakut (Fig. 29d (type locality), f) and Tanjung Lampu Rivers at elevations from 182–420 m. It co-occurs with larvae of P. batanlenos sp. nov. and P. cukiclara sp. nov. Etymology. The species name longabranchias, meaning “long gills” in Latin, refers to the very long and slender shape of the tergalii. Distribution. New Guinea, Batanta Island (Fig. 30). Key to the species of subgenus Papuafiliola from New Guinea (larvae) Based on Kaltenbach et al. 2025. 1 Abdominal terga without protuberances .....................................................2 – Abdominal terga with median protuberances ........................ P. tuberculata 2(1) Femur with brown, hypodermal marking in large blank on anterior side; tergalii very long and narrow ........................................................................3 – Femur without marking in large blank on anterior side; tergalii oval ........... .....................................................................................P. horvathrobi sp. nov. 3(2) Marking on femur shoe-shaped, usually longer than wide; surface of abdominal terga without fine, simple setae ............P. longabranchias sp. nov. – Marking on femur usually wider than long; surface of abdominal terga with fine, simple setae .............................................................P. stenophylla 52 ZooKeys 1259: 1–55 (2025), DOI: 10.3897/zookeys.1259.168419 Thomas Kaltenbach et al.: New species of Papuanatula from New Guinea Discussion Diversity of Papuanatula Previously, 26 species of Papuanatula were reported, 24 of the subgenus Papuanatula s. str. and two of the subgenus Papuafiliola (Fig. 30; Lugo-Ortiz and McCafferty 1999; Kaltenbach et al. 2025). Here, we describe one additional species from the main island of New Guinea and six new species from the rather small island of Batanta, five of the subgenus Papuanatula s. str. and two of the subgenus Papuafiliola. The species from Batanta were found during repeated, intensive collections in the past few years. It should be noted that many water courses were not surveyed yet, and no collections were made above an elevation of 550 m. The distribution of the six new species across the sampled water systems is shown in Table 2. The Kalijakut River system, which originates at the highest point in Batanta, has the largest number of Papuanatula species, four. It also has the highest diversity of Trichoptera species (Kovács et al. 2025). Areas or river systems studied in more detail in New Guinea have often revealed a composition of several co-occurring species, different from other areas or river systems. Examples are: the Je River (Arfak Mountains) with P. arfak sp. nov., P. dumspinae, P. paratuber, P. epituber, and P. pilosa; the Bulolo River near Wau with P. bessa Lugo-Ortiz & McCafferty, P. tuber Lugo-Ortiz & McCafferty, and P. plana Lugo-Ortiz & McCafferty; the Elagaima River (Baliem Valley) with P. obscura Kaltenbach, Kluge & Gattolliat, P. obscurella Kaltenbach, Kluge & Gattolliat, P. tuberculata Kaltenbach, Kluge & Gattolliat, and P. zebrata Kaltenbach, Kluge & Gattolliat; the Cyclops Mountains with P. bessa, P. cyclopomontana Kaltenbach, Kluge & Gattolliat, P. heterochaeta Kaltenbach, Kluge & Gattolliat, and P. stenophylla (Kaltenbach et al. 2025). This gives an idea of the enormous diversity of Papuanatula in New Guinea, and the number of additional species we may discover with further collection activities in New Guinea and the surrounding archipelago. Genetics COI barcode sequences were obtained from five different species, four from the subgenus Papuanatula s. str. and one from the subgenus Papuafiliola (Table 1). The interspecific distance is always between 16% and 25% (K2P), which confirms the values reported by Kaltenbach et al. 2025 for Papuanatula in New Guinea (19%–25%, K2P). The intraspecific distances are always between 0% and 1%, as expected. See also discussion in Kaltenbach et al. 2025. Table 2. Distribution of Papuanatula species in different river systems of Batanta. Batanta north side Batanta south side Waridor Warai Warinkabon Waibin Tanjung Lampu Kalijakut Wailebet P. batantaraja sp. nov. x P. cukiclara sp. nov. x P. cataracta sp. nov. x P. batanlenos sp. nov. x x x x P. horvathrobi sp. nov. x x x P. longabranchias sp. nov. x x 53 ZooKeys 1259: 1–55 (2025), DOI: 10.3897/zookeys.1259.168419 Thomas Kaltenbach et al.: New species of Papuanatula from New Guinea Acknowledgements Most of the financial support for the field trips to Batanta came from Róbert Horváth (Ostoros, Hungary), who provided free accommodation and catering for the second author in Batanta Island. He and the Papua Paradise Eco Resort (Birie Island) provided the base camp and helped organise the field trips. Róbert Horváth and Péter Juhász (Debrecen, Hungary) greatly assisted during the field work. We are also beholden to Kristian Sauyai and Ronnius Sauyai (both from Wailebet, Batanta), our local helpers. András Ambrus (Kópháza, Hungary) recommended the bulb for collecting winged stages of Ephemeroptera. Our study was carried out in compliance with the Memorandum of Understanding signed by the Research Centre for Biology, Indonesian Institute of Sciences, and the Hungarian Natural History Museum. Furthermore, we sincerely thank Michael Balke (SNSB-Zoologische Staatssammlung München, Germany) who contributed a part of the precious material used in this study. Additionally, we are grateful to Céline Stoffel (MZL, UNIL) for her support with lab work and preparation of the COI barcodes. Scanning electron microscopy was performed by Antonio Mucciolo at the University of Lausanne (UNIL). Finally, we are thankful to the reviewers for their valuable comments and corrections. Additional information Conflict of interest The authors have declared that no competing interests exist. Ethical statement No ethical statement was reported. Use of AI No use of AI was reported. Funding No funding was reported. Author contributions Discussions: J-L G. Funding acquisition: TiKo. Investigation: TK, TiKo. Review: J-L G. Validation: TiKo, J-L G. Visualization: TK. Writing – original draft: TK. Writing – review and editing: TiKo. Author ORCIDs Thomas Kaltenbach https://orcid.org/0000-0001-8052-0388 Tibor Kovács https://orcid.org/0000-0003-4577-0394 Jean-Luc Gattolliat https://orcid.org/0000-0001-5873-5083 Data availability All of the data that support the findings of this study are available in the main text. 54 ZooKeys 1259: 1–55 (2025), DOI: 10.3897/zookeys.1259.168419 Thomas Kaltenbach et al.: New species of Papuanatula from New Guinea References Demoulin G (1969) Les éphéméroptères récoltés par la mission danoise du Noona Dan aux îles Philippines et Bismarck. Entomologiske Meddelelser 37: 225–241. 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