Journal of Zoological Systematics and Evolutionary Research最新文献

Southeast Asia’s karst landscapes host a remarkable yet understudied diversity of cave-dwelling fauna, where morphological conservatism often masks true species boundaries. Using an integrative taxonomic framework, we investigated the systematics of the millipede family Cambalopsidae Cook, 1895 inhabiting caves across Thailand, Laos, Myanmar, and Cambodia, combining morphological evidence with mitochondrial cytochrome c oxidase subunit I (COI) sequences. Analyses of 213 specimens revealed the polyphyletic relationships of the two largest genera, Glyphiulus Gervais, 1847 and Plusioglyphiulus Silvestri, 1923, necessitating major taxonomic revision. Consequently, we erect Somsakiulus Seesamut & Likhitrakarn, gen. nov. to accommodate a distinct clade formerly classified within Plusioglyphiulus, and resurrect Cambalomorpha Pocock, 1895 stat. resurr. from synonymy within Glyphiulus. Species delimitation analyses using four single-locus methods (ASAP, GMYC, bPTP, and mPTP) consistently uncovered extensive cryptic diversity, with molecular data identifying substantially more putative species (molecular operational taxonomic units [MOTUs]) than morphology, most notably within the Trachyjulus unciger species complex (46–54 MOTUs vs. 25 morphospecies). This work underscores the limitations of relying on traditional gonopod-based taxonomy alone, elevates the diagnostic importance of peripheral characters, such as the male first legs, and collum and mid-body carinotaxy, and provides a robust systematic framework essential for future evolutionary studies and conservation planning within these vulnerable cave ecosystems.

Three new species of Urosyntexis, U. volita sp. nov., U. forta sp. nov., and U. ensia sp. nov., belonging to the subfamily Anaxyelinae of Anaxyelidae were described and figured based on three well-preserved specimens from the Middle Jurassic Jiulongshan Formation of Northeastern China. We applied geometric morphometric analyses (GMA) to study 17 species with well-preserved forewings of easily confused genera Syntexyela and Urosyntexis and presented the results for the first time. The GMA results further confirmed the classification of our new species and shed light on the differences between the two genera are mainly in the length of 5-M and the emission position of 2r-rs.

In the Western Palaearctic, ice ages played an important role in shaping the genetic diversity of birds, yet the phylogeography of species that persisted in the Mediterranean basin is understudied. Thus, we investigated the genetic diversity, phylogeography and demographic history of the Sardinian Warbler (Curruca melanocephala), a widespread Mediterranean songbird from the Canary Islands, North Africa, across southern Europe, to Turkey and the Middle East. Our study integrated mitochondrial (cytochrome C oxidase subunit I[(COI], cytochrome b [cytb]) and nuclear transforming growth factor-beta 2 (TGFB2) markers, single-nucleotide polymorphisms (SNPs) derived from a genotyping-by-sequencing (GBS) approach and species distribution models (SDMs). Both single markers and genomic SNPs identified four major clades. Several widespread haplotypes, extending from Iberia to Turkey and North Africa, indicate a panmictic pattern across the range of C. m. melanocephala. Among the remaining groups, one corresponds to C. m. momus, another includes individuals ascribable to subspeciesvalverdei and leucogastra, while the last consists of a highly divergent leucogastra haplotype. The ambiguity in subspecies range is further supported by nuclear markers and SNPs, which highlighted great levels of gene flow among populations. Phylogenetic reconstruction showed that the divergence of the clades within C. melanocephala occurred during the Pleistocene in the Middle East region. Demographic analyses suggest that the species maintained relatively stable effective population sizes (N_e) through time, findings supported by SDMs projections, which identify suitable habitats across the Mediterranean during the Last Glacial Maximum (LGM), implying broad persistence rather than contraction to isolated refugia. This study offers new insights into the historical processes that have shaped the apparent panmixia observed today in C. melanocephala and reveals that bird species originating in the Mediterranean may have partially escaped the constraints traditionally associated with glacial refugia along the region’s coasts. The findings also emphasise the value of combining molecular and ecological approaches to disentangle the complex evolutionary dynamics of avian biodiversity hotspots.

Recirculating aquaculture systems (RASs) represent a sustainable solution for intensive fish production, offering 90%–99% water savings compared to conventional systems while preventing nutrient contamination of natural waterways. The accumulation of nitrogenous compounds, driven by factors, like overfeeding, fish waste, and insufficient water exchange, can cause major problems in aquaculture production. This study investigated the optimization of biofiltration systems for nitrogen removal in RAS through a factorial design examining two bacterial species (Nitrosomonas and Nitrobacter), two substrates (sand and straw), and two cell densities in a beluga (Huso huso) sturgeon farm. Results demonstrated distinct functional specialization, with the most effective total ammonia nitrogen (TAN) reduction (upto 85%) achieved by Nitrosomonas in straw and sand systems, while Nitrobacter in straw systems showed 70% nitrite (NO₂⁻) removal. Substrate–microbe interactions were critical, revealing that sand provided an optimal environment for Nitrosomonas, whereas straw optimized Nitrobacter-driven nitrite reduction. These findings provide actionable guidelines for designing targeted biofiltration systems in RAS, with sand–Nitrosomonas recommended for ammonia-dominated systems and straw–Nitrobacter for nitrite mitigation. The study advances sustainable aquaculture practices by demonstrating how substrate-specific microbial optimization can simultaneously improve water quality management and environmental protection.

The genus Tridentiger Gill, 1859 comprises barbeled and nonbarbeled species, which is considered a key character to further divide the genus. Our phylogenetic tree based on 5026-bp sequence data of six genes indicated a well-supported sister relationship between the nonbarbeled T. nudicervicus and the barbeled T. barbatus and T. microsquamis, which rejected monophyly of the nonbarbeled species. Therefore, genus Tridentiger should not be further divided into nonbarbeled and barbeled genera. Due to the presence of the common diagnosis (the outmost row of jaw teeth in tricuspid form), Papuligobius, the closest sister genus, should be assigned as a junior synonym of Tridentiger. Moreover, 12S ribosomal RNA (12S rRNA) Kimura-2-parameter (K2P) distance (0.0000–0.0016) between T. microsquamis and T. radiatus falls in the interval of intraspecific distances (0.0000–0.0030), much smaller than the interspecific distances (0.0122–0.1383). Therefore, T. radiatus should be treated as a synonym of T. microsquamis. K2P distances between the southern and northern lineages of T. barbatus fall in the interval of interspecific distances in 12S rRNA, cytochrome b (Cytb), and recombination activating gene 1 (RAG1) genes, which were delineated as different species in the species delimitations. The mean divergence time between T. kuroiwae in the Ryukyu Islands and its congener, T. brevispinis and T. obscurus in the Japan Archipelago, was dated back to 1.56 million years ago (mya) and close to the formation of the Tokara Gap (~1.5 mya), which might be a barrier driving divergence of the three species. However, as many Tridentiger species show different salinity and habitat preferences, ecological factors might also play important roles in the evolution of the genus Tridentiger.

Island endemics are highly vulnerable due to restricted ranges, small population size, and genetic erosion. The Magellan birdwing on Lanyu Island (Troides magellanus sonani) exemplifies this vulnerability. Despite decades of legal protection, whether it constitutes an independent evolutionarily significant unit (ESU) has remained uncertain. Recent reports of introductions into northern Taiwan highlight the need for a genetic assessment. Here, we applied genome skimming to analyze 46 specimens of the Magellan birdwing, mostly from museum collections. Conservation genetic and phylogenetic analyses revealed that the Lanyu population is genetically distinct, derived from a south-to-north expansion originating in the southern Philippines and colonizing Lanyu around 210,000 years ago. Haplotypes from Lanyu, even spanning a century, remained nearly identical, and those from northern Taiwan were identical to those from Lanyu, confirming human-mediated introductions. These findings establish the Lanyu population as an ESU and emphasize the urgency of targeted conservation actions. This study demonstrates how integrating next-generation sequencing (NGS) with museum specimens can provide critical insights into the evolution and conservation of endangered insular taxa while minimizing impacts on wild populations.

With 300+ species, Eumerus Meigen, 1822, is one of the largest hoverfly genera worldwide. The Canaries are a volcanic archipelago consisting of seven major islands in the Macaronesian region, north-west of Africa. High biodiversity and endemicity levels are reported from these islands, especially for the invertebrates. Regarding the hoverflies, 20 genera are found on the Canaries. Although with the highest alpha diversity amongst hoverfly genera (10 species, of which seven are endemic to the archipelago), Eumerus has not been investigated in depth on the Canaries since 1982. Recent fieldwork and study of collection specimens under an integrative approach (morphology + mitochondrial DNA) have enhanced our knowledge of the Eumerus diversity in this archipelago, including a new species (Eumerus macarius Ricarte and Aguado-Aranda sp. n.), to science endemic to La Palma island. The new species is similar to Eumerus purpureus Macquart in Webb and Berthelot, 1839, for which a neotype is designated. Eumerus aquilius Walker, 1849, is proposed as a junior synonym of E. purpureus. A new Eumerus group endemic to the Macaronesia is defined morphologically and supported with DNA evidence: E. purpureus species group. Relationships and possible diversification of Eumerus from the Canaries are also discussed. After the present work, 11 species of Eumerus are present on the Canaries.

Anguillid eels have a catadromous life cycle, transitioning from deep-sea larvae to adults in estuaries and freshwater environments. It is well-established that adult eels cease feeding and experience gut degeneration during their spawning migration. However, the evolutionary mechanisms behind the removal and recycling of damaged tissues in eels during this process remain unclear. This study aims to identify the genes that may play a role in the adaptation of Anguillid eels to their unique, once-in-a-lifetime deep-sea migration. To investigate these mechanisms, we conducted a comparative genomic analysis using high-quality genomes from four Anguillid eels. We specifically examined genes that exhibited significant expansion or were subject to positive selection. Among the expanded gene families in four eel species, we observed notable enrichment in the endocytosis pathway (p < 0.05). Additionally, using the branch-site model, we detected 65 positively selected genes (PSGs) in the Anguillid eel branch (p < 0.05). Interestingly, we found PSGs are associated with autophagy-lysosome pathways (ALPs), suggesting their role in energy production during periods of nutrient scarcity. This study provides valuable insights into the adaptive mechanisms of Anguillid eels, enhancing our understanding of their survival strategies during migration, despite their being in a nonfeeding state.

Two new species of freshwater amphipods, Crangonyx ipnoecetes n. sp. and Crangonyx furnaricolus n. sp., are described from intermittent bodies of water in Vinton Furnace State Forest (VFSF), Vinton County, Ohio, USA. The descriptions of these species are based on both morphological and molecular analyses, which identify them as only distantly related despite their syntopic occurrences. These species are estimated to have last shared a common ancestor during the Late Cretaceous or early Paleogene (73–50 Ma) and to have diverged from their closest congeners towards the end of this period. Given the region occupied by these species, it is likely that their distributions were influenced by both preglacial habitats, such as the Teays River, and postglacial structures, such as Lake Tight. Our results suggest that significant gaps in knowledge still exist for the amphipod fauna of the Western Allegheny Plateau (eastern USA), with implications for taxonomy and conservation of Crangonyx as well as the natural history of the plateau and surrounding region. Furthermore, the description of these species provides additional evidence for the utilization of shallow hyporheic habitats by epigean Crangonyx spp. These habitats may play significant roles not only for these species, but for other epigean taxa as well.

Biodiversity science depends on rigorous characterization of species diversity and ecological roles, yet the ecology of many invertebrate species remains virtually unknown. One pragmatic way to change this is to make use of deceased animals and their companions, such as by salvaging and examining carcasses reported by citizen scientists. Here, we demonstrate how bird carcasses reported by citizen scientists can help generate functional biodiversity data on parasites. We reveal 44 hippoboscid flies (Diptera: Hippoboscidae) found on 36 of 148 salvaged bird carcasses (~24% success rate). Using the principles of large-scale integrative taxonomy (LIT), we first delimited 10 hippoboscid species. One of these, Pseudolynchia maai Lee & Oboňa, sp. nov., was new to science and is here formally described. We also provide a pictorial key, image-based diagnostics, and molecular diagnostics for all 10 species. We report 25 species interactions between flies and birds. This study illustrates how combining the efforts of citizen scientists and biologists can support species discovery and generate functional parasite–host data.