Diversity

18 pages, 5889 KB

Open AccessArticle

Phytoplankton Diversity and Community Stability Under Nutrient Reduction and Early-Stage Ecological Regulation in a Large Eutrophic Lake

by Fen Zhang, Ruiying Yang, Haiyan Liu, Chenhao Dong, Zhan Hao, Zhaosheng Chu and Tianhao Wu

Diversity 2026, 18(1), 9; https://doi.org/10.3390/d18010009 (registering DOI) - 22 Dec 2025

Abstract

Many lakes worldwide, including in China’s Yangtze River Basin, face eutrophication, which reduces phytoplankton diversity and increases bloom risk. Following severe pollution, these Chinese lakes have undergone substantial control and regulation. However, the efficacy of these measures is still unclear. Focusing on Lake [...] Read more.

Many lakes worldwide, including in China’s Yangtze River Basin, face eutrophication, which reduces phytoplankton diversity and increases bloom risk. Following severe pollution, these Chinese lakes have undergone substantial control and regulation. However, the efficacy of these measures is still unclear. Focusing on Lake Chaohu as a representative case, this study investigated the seasonal phytoplankton dynamics (2022–2023) under concurrent nutrient reduction and a fishing ban. The annual mean concentrations of total nitrogen, total phosphorus, and chlorophyll a were 1.57 mg/L, 0.184 mg/L, and 21.21 μg/L, respectively. The phytoplankton community was dominated by Cyanobacteria, which constituted approximately 75% of the total biomass. Co-occurrence network analysis revealed lower community stability during these warm, Cyanobacteria-dominated periods. Statistical analyses identified total phosphorus and temperature as key drivers, confirming bottom-up control via nutrient limitation as the fundamental mechanism. However, extreme heat events may have partly offset the benefits of nutrient reduction by promoting cyanobacterial dominance, which can decrease phytoplankton diversity. A recorded decrease in phytoplankton phosphorus use efficiency after the fishing ban suggests a potential strengthening of top-down control. These findings highlight that sustained nutrient load reduction is essential to reduce cyanobacterial bloom risk, while continued enforcement of the fishing ban may enhance the regulatory effect of top-down control on cyanobacterial blooms, thereby improving the stability and diversity of phytoplankton communities. Full article

(This article belongs to the Section Freshwater Biodiversity)

17 pages, 4021 KB

Open AccessArticle

Molecular and Morphological Analyses of the Ichthyoplankton Community in Yueqing Bay, China, Reveal High Species Diversity and Variation in Fish Spawning Activity

by Rijin Jiang, Amiri Rajabu Mohamedi, Rui Yin, Tereza M. Magati, Yehoshafati Elton Anton, James Leonard Lusana and Yongjiu Chen

Diversity 2026, 18(1), 8; https://doi.org/10.3390/d18010008 (registering DOI) - 22 Dec 2025

Abstract

Yueqing Bay in China supports important marine resources that sustain local fisheries and food security, but increasing anthropogenic pressures and natural environmental changes threaten its biodiversity. This study used morphological identification, COI DNA barcoding, and 12S DNA metabarcoding to assess ichthyoplankton composition and [...] Read more.

Yueqing Bay in China supports important marine resources that sustain local fisheries and food security, but increasing anthropogenic pressures and natural environmental changes threaten its biodiversity. This study used morphological identification, COI DNA barcoding, and 12S DNA metabarcoding to assess ichthyoplankton composition and fish spawning patterns. A total of 13,415 eggs and 17,291 larvae were collected using horizontal and vertical plankton nets. Morphological analysis identified 58 taxa, while molecular methods detected 21 species (COI) and 48 species (12S), with an overall total of 105 species from 78 genera and 42 families. Spawning activity showed clear seasonal and spatial patterns, with the highest abundance and diversity in spring and summer, particularly around Ximen Island and the Bay mouth. These areas function as key spawning and nursery grounds. 12S DNA metabarcoding contributed strongly to species detection, especially for cryptic and morphologically indistinguishable larvae, complementing traditional surveys. The findings provide essential baseline information for monitoring fish stocks, protecting critical habitats, and improving fishery management strategies under increasing anthropogenic and climate-related pressures in Yueqing Bay. Full article

(This article belongs to the Special Issue Marine Zooplankton and Ichthyoplankton Ecology: Patterns, Processes, and Perspective)

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16 pages, 2270 KB

Open AccessArticle

Water Quality Assessment and Spatial Heterogeneity Distribution of Freshwater Shellfish in Wutong River

by Haitao Wang, Le Wang, Tangbin Huo and Wang Zhang

Diversity 2026, 18(1), 7; https://doi.org/10.3390/d18010007 (registering DOI) - 22 Dec 2025

Abstract

The Wutong River, located in northeastern China’s Heilongjiang Province, serves as an important habitat and spawning ground for fish and freshwater shellfish. To investigate the influence of geographic and geomorphic changes on the river basin ecology, the water environment and spatial heterogeneity of [...] Read more.

The Wutong River, located in northeastern China’s Heilongjiang Province, serves as an important habitat and spawning ground for fish and freshwater shellfish. To investigate the influence of geographic and geomorphic changes on the river basin ecology, the water environment and spatial heterogeneity of freshwater shellfish distribution were monitored in both summer and autumn of 2024. Key water quality indicators were analyzed, including basic parameters (pH and dissolved oxygen), eutrophication indices (nitrogen, phosphorus, and chlorophyll), and pollutant levels (nitrite nitrogen, petroleum, and volatile phenol). Water quality was assessed using the single-factor index method and the Nemerow pollution index method. Results indicated that in 2024, the Wutong River was weakly acidic in summer and weakly alkaline in autumn, with overall high dissolved oxygen levels. The Guanmenzuizi Dam site exhibited the best water quality. According to the single-factor evaluation, water quality in autumn was better than in summer, with iron, manganese, and volatile phenol as the primary pollutants, followed by total nitrogen and permanganate index. Based on the Nemerow index, the river generally met China’s Class III surface water standards. Water quality showed a trend of initial improvement followed by deterioration along the river course. Among 100 sampling points, Unio douglasiae had the highest occurrence rate (76%), followed by Cipangopaludina cahayensis (66%). Other species occurred in ≤50% of samples, with Polypylis hemisphaerula being the rarest (3%). The average species occurrence rate increased from upstream to downstream. This study provides a data baseline for understanding the water environment of the Wutong River and supports research on biodiversity and ecological conservation. Full article

(This article belongs to the Special Issue Ecology and Conservation of Freshwater Bivalves)

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31 pages, 4505 KB

Open AccessArticle

Climate and Landscape Drivers of Endangered Bird Distributions and Richness in South Korea: Random Forest Projections Across Municipalities and National Parks Under SSP Scenarios

by Jae-Ho Lee, Man-Seok Shin, Eun-Seo Lee, Jae-Seok Lee and Chang-Wan Seo

Diversity 2026, 18(1), 6; https://doi.org/10.3390/d18010006 (registering DOI) - 21 Dec 2025

Abstract

Climate change poses an unprecedented threat to global biodiversity, with birds serving as critical indicators of ecosystem responses. This study assessed the impacts of climate change on 29 endangered bird species in South Korea, a critical stopover region within the East Asian-Australasian Flyway [...] Read more.

Climate change poses an unprecedented threat to global biodiversity, with birds serving as critical indicators of ecosystem responses. This study assessed the impacts of climate change on 29 endangered bird species in South Korea, a critical stopover region within the East Asian-Australasian Flyway (EAAF). Using Random Forest models, we predicted current (2010 baseline) and future species distributions under two climate scenarios (SSP2-4.5 and SSP5-8.5) for four time periods (2030s, 2050s, 2070s, and 2090s). Model performance was robust, with a mean AUC of 0.844 ± 0.122 across all species and 72.4% of species achieving AUC ≥ 0.80. Elevation emerged as the most influential predictor for 44.8% of species, followed by precipitation of the driest month (17.2%) and distance to water bodies (10.3%). Current species richness patterns showed spatial heterogeneity, with higher concentrations along coastal wetlands, particularly in the western and southern coasts and Jeju Island. Under SSP2-4.5, species richness patterns remained relatively stable through 2090, while SSP5-8.5 projected more dramatic shifts, particularly after 2070. Coastal regions and national parks exhibited differential responses, with some areas showing increases and others experiencing declines in species richness. High-elevation national parks, including Mt. Hallasan, Mt. Seoraksan, and Mt. Odaesan, demonstrated potential to serve as climate refugia, maintaining relatively stable species richness under both scenarios. Our spatial analysis at municipality and national park levels identified priority conservation areas and emphasized the need for climate refugium identification, habitat connectivity along elevational gradients, and adaptive management strategies. The findings provide actionable guidance for science-based conservation planning and contribute to international efforts to protect migratory birds along the EAAF. Urgent conservation measures are needed to safeguard coastal wetlands and establish ecological corridors to facilitate species range shifts under changing climatic conditions. Full article

(This article belongs to the Section Biodiversity Conservation)

11 pages, 3575 KB

Open AccessArticle

Unrecognized Ant Megadiversity in the Australian Monsoonal Tropics: The Meranoplus berrimah Schödl and Meranoplus snellingi Schödl Complexes

by Alan N. Andersen, François Brassard and Benjamin D. Hoffmann

Diversity 2026, 18(1), 5; https://doi.org/10.3390/d18010005 (registering DOI) - 19 Dec 2025

Abstract

We integrate morphological variation, CO1 distance and clustering, and geographic distribution to document unrecognized diversity within Meranoplus ‘berrimah’ and M. ‘snellingi’, members of the M. diversus group of specialist seed harvesters from Australia’s monsoonal (seasonal) tropics. This follows similar [...] Read more.

We integrate morphological variation, CO1 distance and clustering, and geographic distribution to document unrecognized diversity within Meranoplus ‘berrimah’ and M. ‘snellingi’, members of the M. diversus group of specialist seed harvesters from Australia’s monsoonal (seasonal) tropics. This follows similar analyses of two other monsoonal ‘species’ of the group, M. ajax and M. unicolor, showing that both represent highly diverse complexes comprising an estimated 100 species each. We recognize eleven species among the 34 sequenced specimens attributable to M. berrimah and ten species among the 29 sequenced specimens attributable to M. snellingi. Images of all these species are provided. The M. berrimah complex has a far broader geographic range than was apparent when M. berrimah was originally described, occurring in the Kimberley region of Western Australia in addition to the Top End of the Northern Territory, whereas the M. snellingi complex appears to be restricted to the Top End. The limited geographic representation of our sequenced specimens suggests that many additional species occur in both complexes. We estimate that the M. snellingi complex contains 15–20 species in total, and that this number is considerably higher in the M. berrimah complex because of its broader distributional range. Our study provides further evidence that monsoonal Australia is a global centre of ant diversity, but it is not formally recognized as such because the great majority of its species is undescribed. Full article

(This article belongs to the Section Animal Diversity)

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16 pages, 3482 KB

Open AccessArticle

Prolonged Summer Coccolithophore Blooms in the Northeastern Black Sea: Anomaly or Emerging Trend?

by Vladimir Silkin, Larisa Pautova, Valeryi Chasovnikov, Oleg Podymov and Viacheslav Kremenetskiy

Diversity 2026, 18(1), 4; https://doi.org/10.3390/d18010004 (registering DOI) - 19 Dec 2025

Abstract

In the summer of 2022 and 2023, a shift was detected in the biological carbon pump system in the northeastern Black Sea, deviating from the traditional seasonal pattern: carbonate pump (late spring–early summer) → organic pump (summer–autumn). The coccolithophore Gephyrocapsa (=Emiliania) [...] Read more.

In the summer of 2022 and 2023, a shift was detected in the biological carbon pump system in the northeastern Black Sea, deviating from the traditional seasonal pattern: carbonate pump (late spring–early summer) → organic pump (summer–autumn). The coccolithophore Gephyrocapsa (=Emiliania) huxleyi (Lohmann) P. Reinhardt, 1972, responsible for the carbonate pump, dominated until the end of July, while the intensive growth of large diatom species representing the organic pump was shifted to August–September. These changes were associated with deviations in meteorological conditions from long-term averages. The absence of strong wind-induced mixing led to water column stabilization and the formation of a shallow thermocline. Low nitrogen and high phosphorus concentrations promoted a coccolithophore bloom in July, while low nitrogen levels prevented intensive diatom growth during summer. Thermocline deepening in September 2022 and August 2023 enhanced organic pump operation via a short-term bloom of the large diatom Pseudosolenia calcar-avis (Schultze) B.G. Sundström, 1986. Full article

(This article belongs to the Section Marine Diversity)

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46 pages, 45013 KB

Open AccessArticle

Two New Pseudochromadora Species and the First Korean Record of Metachromadora itoi Kito, 1978, with SEM-Based Insights into Buccal Cavity Morphology

by Hyo Jin Lee, Heegab Lee, Seungyeop Han, Ji-Hoon Kihm and Hyun Soo Rho

Diversity 2026, 18(1), 3; https://doi.org/10.3390/d18010003 - 19 Dec 2025

Abstract

Three free-living marine nematode species of the family Desmodoridae are described and illustrated based on light and scanning electron microscopy. Pseudochromadora paraparva sp. nov. was collected from muddy sand sediments at Eulwangri Beach, Incheon, Korea, and P. capitata sp. nov. from sublittoral muddy [...] Read more.

Three free-living marine nematode species of the family Desmodoridae are described and illustrated based on light and scanning electron microscopy. Pseudochromadora paraparva sp. nov. was collected from muddy sand sediments at Eulwangri Beach, Incheon, Korea, and P. capitata sp. nov. from sublittoral muddy sediments off Jindo Island, Korea. Metachromadora itoi Kito, 1978, is also recorded for the first time from Korean waters, based on specimens from sandy sediments off Jeju Island. Pseudochromadora paraparva sp. nov. is distinguished from P. parva Gagarin & Thanh, 2008 and related congeners by having a tripartite cephalic region consisting of a jar-shaped main capsule, an anterior transition zone with weaker cuticle bearing the cephalic setae, and a highly elevated hat-shaped labial region. It additionally shows a sexually dimorphic amphideal fovea, a unique arrangement of precloacal thorns, a gubernaculum with a dorsal apophysis, and ventral thorns lacking cuticular hillocks. Pseudochromadora capitata sp. nov. is characterized by a cephalic region composed of a rounded labial region and a thickly cuticularized main capsule, together with a sexually dimorphic amphideal fovea, arcuate spicules with a large hammer-shaped capitulum, a gubernaculum with a dorsal apophysis, and 3–8 precloacal and 3–5 postcloacal thorns arranged in a row. Molecular data (18S and 28S rRNA) were generated for both new species, and phylogenetic analyses support their placement within the genus Pseudochromadora and provide molecular evidence distinguishing them from closely related congeners. Scanning Electron Microscope (SEM) observations of M. itoi also revealed multiple configurations of the buccal cavity, providing additional morphological information useful for understanding structural variation within the genus. These findings refine the taxonomic framework within the Desmodoridae and expand current knowledge of morphological diversity in free-living marine nematodes. Full article

(This article belongs to the Special Issue Distribution, Biodiversity, and Ecology of Nematodes)

18 pages, 1374 KB

Open AccessArticle

Analysis of the Distribution of Epiphytic Corticolous Lichens in the Forests Along an Altitudinal Gradient in Barluk Mountain National Nature Reserve in Xinjiang, China

by Nasima Ablimit, Reyhangul Mamatali, Dolathan Toksun, Muhammad Shahid Iqbal and Anwar Tumur

Diversity 2026, 18(1), 2; https://doi.org/10.3390/d18010002 - 19 Dec 2025

Abstract

Epiphytic corticolous lichens are vital components of forest ecosystems, yet their species composition and distribution patterns along altitudinal gradients in the Populus tremula forests of Barluk Mountain National Nature Reserve, Xinjiang, China, remain understudied. This study analyzes the diversity and distribution of epiphytic [...] Read more.

Epiphytic corticolous lichens are vital components of forest ecosystems, yet their species composition and distribution patterns along altitudinal gradients in the Populus tremula forests of Barluk Mountain National Nature Reserve, Xinjiang, China, remain understudied. This study analyzes the diversity and distribution of epiphytic corticolous lichens in these forests along an altitudinal gradient. Field research was conducted at six sites (940–1450 m) from June to July 2023–2024, with samples collected from 576 quadrats on 48 Populus tremula trees. Lichen identification involved morphological, anatomical, and chemical analyses. Data on cover and frequency were analyzed to calculate importance values (IV), diversity indices, and floristic similarity (Sørensen’s index). NMDS and TWINSPAN were used to explore distribution patterns along the altitude gradient. In total, 28 epiphytic lichen species were identified, with diversity indices peaking at 1040 m. Dominant species exhibited significant variations in IV across altitudes (P < 0.05), and NMDS/TWINSPAN revealed distinct community clustering associated with elevation. Sørensen’s index indicated a low similarity (<30%) between the highest and lowest altitude sites. This study provides a baseline for biodiversity conservation and forest management in arid and semi-arid land mountain ecosystems. Full article

(This article belongs to the Section Microbial Diversity and Culture Collections)

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19 pages, 6176 KB

Open AccessArticle

Latitudinal Patterns and Macroalgal Diversity in Marine Protected Areas Along the Southwest Atlantic

by Cláudia Santiago Karez, Edlin Guerra-Castro, Valéria Cassano, Carolina Cezar da Silva, Pedro Smith Menandro, Ricardo da Gama Bahia, Carlos Frederico Deluqui Gurgel, José Marcos de Castro Nunes, Gabriel do Nascimento Santos, Mutue Toyota Fujii, Frederico Tapajós de Souza Tâmega, Aryane Vitória Curvelo de Oliveira, Rodrigo Tomazetto de Carvalho, Fernando Coreixas de Moraes and Leonardo Tavares Salgado

Diversity 2026, 18(1), 1; https://doi.org/10.3390/d18010001 - 19 Dec 2025

Abstract

Macroalgae provide key ecosystem services, forming habitats such as kelp and fucoid forests, rhodolith beds, and coralline reefs that sustain high biodiversity. However, multiple stressors, including climate change, harmful fishery practices, and pollution and coastal urbanization are driving macroalgal diversity loss and changing [...] Read more.

Macroalgae provide key ecosystem services, forming habitats such as kelp and fucoid forests, rhodolith beds, and coralline reefs that sustain high biodiversity. However, multiple stressors, including climate change, harmful fishery practices, and pollution and coastal urbanization are driving macroalgal diversity loss and changing species composition and abundance. This study aims to assess macroalgal representativeness, richness and endemism in 16 Marine Protected Areas (MPAs), including four oceanic islands, and test if macroalgal assemblages in MPAs are distributed along a latitudinal gradient (0–29° S) in the Southwest Atlantic. To investigate the processes underlying community patterns, β-diversity was decomposition turnover and nestedness components. The complexity of taxonomic structure was measured by taxonomic distinctness. Overall, the studied MPAs comprised 695 macroalgal taxa, about 69% of Brazilian taxa, and 36% of the endemics. Rhodophyta were dominant (449 species) in most studied areas, except at Trindade and Martim Vaz Archipelago MPA, followed by Chlorophyta (158 species) and Ochrophyta (88 species). Macroalgal species composition in MPAs varied with latitude, and not with area size. They were continuously distributed across northeastern, eastern and southeastern Brazil and oceanic island ecoregions, between Fernando de Noronha (3° S) and São Paulo Litoral Norte (23° S) MPAs. Macroalgal diversity dissimilarity among MPAs was 92%, dominated by the turnover component (88%) and nestedness as a minor component (4%), indicating that dissimilarities are mainly driven by the replacement of species, rather than a gradual loss or gain of species. Effective protection of these MPAs should be prioritized as they harbor highly diverse, unique, and heterogeneous macroalgal assemblages along the SWA, surrounded by heavily impacted areas. Assessment of human impacts on macroalgal habitats in MPAs would contribute to defining effective management actions. Mid- and offshore shelf macroalgal habitats, particularly rhodolith beds, which harbor rare kelp species and mesophotic reefs, remain underprotected, and should be integrated into marine spatial planning for biodiversity conservation. Full article

(This article belongs to the Special Issue Ecology and Biogeography of Marine Benthos—2nd Edition)

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7 pages, 522 KB

Open AccessCommunication

A Multidimensional Framework for Understanding Microbial Mutualisms

by Matan Shelomi

Diversity 2025, 17(12), 871; https://doi.org/10.3390/d17120871 - 18 Dec 2025

Abstract

Microbial mutualisms are still commonly described as obligate or facultative, but this dichotomy is insufficient to describe the complexity of host–microbe interactions. A multi-dimensional conceptual framework that accounts for asymmetry in dependency and taxonomic membership flexibility is introduced. This framework allows the classification [...] Read more.

Microbial mutualisms are still commonly described as obligate or facultative, but this dichotomy is insufficient to describe the complexity of host–microbe interactions. A multi-dimensional conceptual framework that accounts for asymmetry in dependency and taxonomic membership flexibility is introduced. This framework allows the classification of mutualisms by how they are structured and for whom the interaction is necessary. The dimensions include dependency considered independently for both organisms, and both the global/potential and individual/actual microbiome diversities. Examples are given primarily from the field of insect–microbe interactions, showing how past frameworks cannot fully encompass the diversity of symbioses. This new framework integrates symbiont community complexity and highlights functional redundancy, which is useful for understanding host plasticity, vulnerability, invasiveness, and resilience. Full article

(This article belongs to the Section Microbial Diversity and Culture Collections)

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4 pages, 147 KB

Open AccessEditorial

Wildlife in Natural and Altered Environments: What Is Special About This Issue?

by Francisco Javier Zamora-Camacho

Diversity 2025, 17(12), 870; https://doi.org/10.3390/d17120870 - 18 Dec 2025

Abstract

The interaction between humans and the environment often entails the deterioration of the latter triggered by the actions of the former [...] Full article

(This article belongs to the Special Issue Wildlife in Natural and Altered Environments)

21 pages, 10278 KB

Open AccessArticle

DNA Barcoding for Managing Blackberry Genetic Resources on Black Sea Coast (Russia)

by Igor Yu. Zhuravlev, Anton V. Korzhuk, Elena S. Tyurina, Nadezhda A. Dobarkina, Elena N. Markova, Evgenija I. Gereeva, Ioanna M. Protasova, Mikhail T. Menkov, Irina V. Rozanova, Lilija Yu. Shipilina, Elena K. Khlestkina and Alexey S. Rozanov

Diversity 2025, 17(12), 869; https://doi.org/10.3390/d17120869 - 18 Dec 2025

Abstract

Accurate species identification in blackberries (Rubus spp.) is difficult because of morphological similarity and frequent hybridization. We studied 56 wild accessions from the Sirius Federal Territory (Russia), representing coastal and foothill ecosystems of the Black Sea region. Multilocus DNA barcoding with the [...] Read more.

Accurate species identification in blackberries (Rubus spp.) is difficult because of morphological similarity and frequent hybridization. We studied 56 wild accessions from the Sirius Federal Territory (Russia), representing coastal and foothill ecosystems of the Black Sea region. Multilocus DNA barcoding with the plastid rbcL gene and nuclear ITS1 and ITS2 regions revealed signals of hybridization and hidden diversity. The rbcL marker showed low variation, grouping most accessions into two clusters with several singletons, which limited its use for distinguishing species. In contrast, ITS1 and ITS2 showed higher variation, forming six clusters and eight singletons, and allowed for clear separation of taxa such as Rubus caesius L., R. irritans Focke, and R. amabilis Focke. Accession 3 carried a raspberry (closely to R. corchorifolius L.fil) plastid haplotype, pointing to a hybrid origin. We also found groups of nearby plants with identical mutations, which likely reflect clonal spread with fixed somatic changes or the persistence of recent hybrid lineages. At the same time, accessions collected up to 140 km apart did not form separate clusters, showing weak geographic structuring along the coast. The results demonstrate that multilocus barcoding can reveal not only species boundaries but also evolutionary processes among Rubus such as hybridization, clonal propagation, and early stages of speciation. Full article

(This article belongs to the Special Issue Genetic Diversity, Breeding and Adaption Evolution of Plants)

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13 pages, 912 KB

Open AccessArticle

Revisiting the Invasion: A Success Story of Crayfish Species in Piedmont Plain Lakes (NW Italy)

by Angela Boggero, Marco Orlandi, Silvia Zaupa and Lyudmila Kamburska

Diversity 2025, 17(12), 868; https://doi.org/10.3390/d17120868 - 18 Dec 2025

Abstract

Crayfish often become invasive when introduced to new waters. From the late 19th to the late 20th century, the commercial import of North American species (e.g., Faxonius limosus, Pacifastacus leniusculus, Procambarus clarkii) into Europe for food, ornamental aquaculture, and restocking [...] Read more.

Crayfish often become invasive when introduced to new waters. From the late 19th to the late 20th century, the commercial import of North American species (e.g., Faxonius limosus, Pacifastacus leniusculus, Procambarus clarkii) into Europe for food, ornamental aquaculture, and restocking native crayfish populations after crayfish plague succeeded due to their adaptability, high reproductive rates, and resilience. Extensive baited-trap monitoring of Piedmont lakes carried in 2025 confirmed the occurrence of two invasive crayfish species (F. limosus, and P. clarkii) in 10 of 17 lakes and recorded P. clarkii for the first time ever in lakes Pistono, San Michele, and Sirio, expanding our knowledge of their distribution in Piedmont freshwaters. Since all detected species are listed as Invasive Alien Species of Union Concern, protecting the ecological integrity of Piedmont’s freshwaters requires coordinated action by member states, regional authorities, policymakers, and water managers to prevent and control their spread and to improve information sharing. Non-native crayfish occurrence is influenced not only by hydrological and habitat connectivity and predator–prey interactions but also by illegal activities that supply the food market. Full article

(This article belongs to the Special Issue Diversity and Biogeography of Crustaceans in Continental Waters)

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16 pages, 1773 KB

Open AccessArticle

Seasonal Dynamics of Phytoplankton Community Structure and Environmental Drivers in the Coastal Waters of the Leizhou Peninsula, China

by Jianming Li, Menghan Gao, Bihong Liu, Yingyi Fan, Junyu Wei, Yulei Zhang, Feng Li, Ning Zhang and Zhangxi Hu

Diversity 2025, 17(12), 867; https://doi.org/10.3390/d17120867 - 17 Dec 2025

Abstract

To investigate the seasonal dynamics of phytoplankton community structure and its relationship with environmental factors in the coastal waters of the Leizhou Peninsula, China, surveys were conducted at 21 stations during four seasonal cruises: autumn (August 2022), winter (December 2022), spring (March 2023), [...] Read more.

To investigate the seasonal dynamics of phytoplankton community structure and its relationship with environmental factors in the coastal waters of the Leizhou Peninsula, China, surveys were conducted at 21 stations during four seasonal cruises: autumn (August 2022), winter (December 2022), spring (March 2023), and summer (June 2023). A total of 174 phytoplankton species from 7 phyla were identified. Species richness peaked in summer (93 species, 5 phyla), followed by winter (80 species, 3 phyla), spring (79 species, 5 phyla), and autumn (75 species, 5 phyla). Bacillariophyta dominated throughout the year, with Skeletonema costatum (Greville) Cleve 1878 and Chaetoceros lorenzianus Grunow 1863 being consistently dominant across all seasons. Phytoplankton cell density showed a distinct seasonal pattern, highest in autumn, followed by summer, and lower in spring and winter. Diversity indices (H, J, D) indicated moderately to heavily polluted waters. Redundancy analysis identified salinity, dissolved inorganic nitrogen, chlorophyll a (Chl a), pH, water temperature, chemical oxygen demand, and dissolved silicon as key environmental drivers, with their influence varying seasonally: salinity was strongest in summer, Chl a in winter, and multiple factors jointly shaped the community in spring and autumn. This study provides a comprehensive assessment of phytoplankton biodiversity and clarifies the environmental drivers of their distribution in the coastal waters of the Leizhou Peninsula, China. Full article

(This article belongs to the Special Issue Harmful Algal Blooms: Distribution and Diversity)

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12 pages, 1543 KB

Open AccessArticle

Seed-Carrying Ant Assemblages in a Fragmented Dry Forest Landscape: Richness, Composition, and Ecological Implications

by Rodrigo G. Pol, Mariana Pereyra and Leonardo Galetto

Diversity 2025, 17(12), 866; https://doi.org/10.3390/d17120866 - 17 Dec 2025

Abstract

Habitat fragmentation profoundly alters ecological processes such as seed predation and dispersal. Ants play a central role as seed removers and dispersers, yet the effects of fragmentation on seed-carrying ant assemblages in dry tropical forests remain insufficiently studied. In this work, we examined [...] Read more.

Habitat fragmentation profoundly alters ecological processes such as seed predation and dispersal. Ants play a central role as seed removers and dispersers, yet the effects of fragmentation on seed-carrying ant assemblages in dry tropical forests remain insufficiently studied. In this work, we examined the influence of forest fragmentation on seed-carrying ants in the Chaco forests of central Argentina. Ants were sampled across nine forest fragments of varying sizes and two continuous forests within an agroecosystem landscape, and species richness, composition, and occurrence were analyzed. Our results revealed that species richness did not vary significantly with fragment size; however, fragmentation caused pronounced shifts in species composition, with clear distinctions between continuous forests and fragments. Large-bodied specialist harvester ants declined in fragments, whereas small- to medium-sized generalist species from genera such as Pheidole and Solenopsis persisted. These compositional changes suggest that although overall seed removal rates may remain stable, the functional quality of seed dispersal likely diminishes. This study highlights the sensitivity of seed-carrying ant assemblages to habitat fragmentation and underscores the need for further research that integrates behavioral and landscape-scale approaches to better assess impacts on seed removal, dispersal, and forest regeneration in fragmented dry forests. Full article

(This article belongs to the Special Issue Systematics, Evolution and Diversity in Ants)

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13 pages, 3127 KB

Open AccessArticle

COI Gene-Based DNA Barcode Reference Database for Beetles in a Temperate Biodiversity Hotspot: Insights from the Liancheng Nature Reserve, Gansu Province, China

by Kang Chang, Pengcheng Nie, Youssef Dewer, Raul Narciso C. Guedes, Xiaoxiao Chen and Suqin Shang

Diversity 2025, 17(12), 865; https://doi.org/10.3390/d17120865 - 17 Dec 2025

Abstract

Beetles (Coleoptera) represent one of the most diverse insect groups and play vital ecological roles, yet their accurate identification is often challenging due to morphological similarities among taxa. DNA barcoding has emerged as a powerful and reliable tool for species-level identification and biodiversity [...] Read more.

Beetles (Coleoptera) represent one of the most diverse insect groups and play vital ecological roles, yet their accurate identification is often challenging due to morphological similarities among taxa. DNA barcoding has emerged as a powerful and reliable tool for species-level identification and biodiversity monitoring. In this study, we established a local DNA barcode reference database for beetles in the Liancheng Nature Reserve, Gansu Province, China. From May to August 2024, beetle specimens were collected and identified using both morphological traits and DNA barcoding. Three species delimitation methods—Automatic Barcode Gap Discovery (ABGD), Assemble Species by Automatic Partitioning (ASAP), and Bayesian Poisson Tree Processes (bPTP)—were employed as complementary analytical tools, and phylogenetic relationships were inferred from cytochrome c oxidase subunit I (COI) sequences. A total of 164 COI sequences (650 bp) were obtained, representing 126 beetle species from 95 genera and 20 families. DNA barcoding successfully resolved morphologically ambiguous taxa, with many sequences reported here for the first time. Phylogenetic analysis revealed that species within the same genus formed cohesive clades before clustering at the family level, confirming the species-level discriminative power of the COI gene. Collectively, these findings demonstrate that COI-based DNA barcoding is a powerful complement to traditional taxonomy. The establishment of this preliminary reference database provides a valuable molecular resource for beetle identification and a practical tool to support biodiversity conservation, resource management, and long-term monitoring in the Liancheng Nature Reserve. Full article

(This article belongs to the Special Issue Arthropod Diversity in Arid and Desert Ecosystems)

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18 pages, 1692 KB

Open AccessFeature PaperArticle

Turnover, Uniqueness, and Environmental Filtering Shape Helminth Parasite Metacommunities in Freshwater Fish Pseudoxiphophorus bimaculatus (Cyprinodontiformes: Poeciliidae)

by Ivonne López-del-Monte, Oscar Rico-Chávez, Juan Manuel Caspeta-Mandujano, Edgar Fernando Mendoza-Franco, Norman Mercado-Silva, Jesús Montoya-Mendoza, Miguel Rubio-Godoy, Ismael Guzmán-Valdivieso, Benjamín Quiroz-Martínez and Guillermo Salgado-Maldonado

Diversity 2025, 17(12), 864; https://doi.org/10.3390/d17120864 - 17 Dec 2025

Abstract

Understanding the processes that shape parasite community structure across spatial scales is essential for linking ecological theory with host–parasite dynamics. Using a metacommunity framework, we examined the metacommunity of helminth parasites infecting the freshwater fish Pseudoxiphophorus bimaculatus across 11 sites along the La [...] Read more.

Understanding the processes that shape parasite community structure across spatial scales is essential for linking ecological theory with host–parasite dynamics. Using a metacommunity framework, we examined the metacommunity of helminth parasites infecting the freshwater fish Pseudoxiphophorus bimaculatus across 11 sites along the La Antigua River basin (Veracruz, Mexico). We combined β-diversity partitioning, local and species contributions to diversity, elements of metacommunity structure (EMS), and variance partitioning to identify the mechanisms underlying spatial variation in parasite composition. Helminth metacommunity was dominated by a few widespread taxa, with balanced variation in species abundances—indicative of turnover—emerging as the main driver of β-diversity at both host and site levels. Both rare and common species contributed disproportionately to regional diversity. EMS analyses revealed coherent, non-random community structures that varied from nested to quasi-Gleasonian and quasi-Clementsian types among sites and guilds, suggesting that species respond individually to shared environmental gradients. Variance partitioning indicated that environmental filtering, particularly through habitat structure, explained most of the variation in community composition, exceeding the effects of water quality and host size. Overall, our results demonstrate that turnover, species uniqueness, and environmental filtering interact to shape helminth parasite metacommunities in tropical freshwater systems, highlighting the integrative role of environmental heterogeneity and dispersal limitation in parasite community assembly. Full article

(This article belongs to the Section Freshwater Biodiversity)

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14 pages, 2776 KB

Open AccessArticle

DNA Barcode Identification for Gastropod and Bivalve Species in Coastal Bays and Islands of Vietnam

by Nguyen Chi Mai, Pham Thi Hoe, Le Quang Trung, Nguyen Tuong Van, Luu Xuan Hoa, Hoang Dinh Chieu, Do Cong Thung, Bui Minh Tuan, Pham Tran Dinh Nho, Le Quynh Lien and Tran My Linh

Diversity 2025, 17(12), 863; https://doi.org/10.3390/d17120863 - 16 Dec 2025

Abstract

Vietnam, a coastal and tropical country, harbors a high diversity of marine mollusks, particularly gastropods and bivalves. However, the taxonomy of these groups is frequently confounded by their morphological similarities and pronounced plasticity. The aim of this study was to assemble the first [...] Read more.

Vietnam, a coastal and tropical country, harbors a high diversity of marine mollusks, particularly gastropods and bivalves. However, the taxonomy of these groups is frequently confounded by their morphological similarities and pronounced plasticity. The aim of this study was to assemble the first comprehensive barcode reference library for marine gastropods and bivalves in Vietnam. The samples were collected from four different marine areas. We identified 31 morphospecies belonging to 28 genera, 24 families, and 11 orders. A total of 49 COI-5P sequences were obtained and categorized into 31 taxa (30 to species levels), 83.67% of which were found to be concordant with morphology-based identifications. The topology of Neighbor-Joining trees also grouped the sequences of the same species into monophyletic clusters, which were congruent with 31 taxa. Twenty eight species were placed in single Barcode Index Numbers (BINS) and three in two BINs. Barcode gaps were found for all species. As a result, the obtained COI-5P barcodes are suitable for species identification of 17 gastropod species and 14 bivalves. All COI-5P barcodes have been deposited in GenBank, BOLD, and the website for the national project “Development of DNA Database for Valuable Marine Invertebrates”. Full article

(This article belongs to the Special Issue Diversity in 2025)

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17 pages, 9113 KB

Open AccessArticle

Climate-Driven Habitat Dynamics of Ormosia xylocarpa: The Role of Cold-Quarter Precipitation as a Regeneration Bottleneck Under Future Scenarios

by Wen Lu and Mao Lin

Diversity 2025, 17(12), 862; https://doi.org/10.3390/d17120862 - 16 Dec 2025

Abstract

The Maximum Entropy (MaxEnt) model, integrated with ArcGIS (a geographic information system), was employed to project potential species distribution under current conditions and future climate scenarios (SSP1–2.6, SSP2–4.5, SSP5–8.5) for the 2050s, 2070s, and 2090s. Model optimization involved testing 1160 parameter combinations. The [...] Read more.

The Maximum Entropy (MaxEnt) model, integrated with ArcGIS (a geographic information system), was employed to project potential species distribution under current conditions and future climate scenarios (SSP1–2.6, SSP2–4.5, SSP5–8.5) for the 2050s, 2070s, and 2090s. Model optimization involved testing 1160 parameter combinations. The optimized model (FC = LQ, RM = 0.1) exhibited significantly improved predictive performance, with an average AUC of 0.967. Under current conditions, the estimated core suitable habitat spans 35.62 × 10⁴ km², primarily located in southern China. Future projections indicated a non-linear trajectory: an initial contraction of total suitable area by mid-century, followed by a substantial expansion by the 2090s, particularly under high-emission scenarios. Simultaneously, the distribution centroid shifted northwestward. The primary factors influencing distribution were the annual mean temperature (Bio1, 41.1%) and the precipitation of the coldest quarter (Bio19, 20.0%). These findings establish a critical scientific basis for developing climate-adaptive conservation strategies, including the identification of priority climate refugia in Fujian province, China, and planning for assisted migration to northwestern regions. Full article

(This article belongs to the Section Plant Diversity)

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