Diversity

15 pages, 3420 KiB

Open AccessArticle

Gonadal Cycle of Corbicula largillierti (Bivalvia: Cyrenidae) in a Pampean Streams, Argentina

by Cristina Damborenea, Yeny Labaut, Pablo Penchaszadeh, Gonzalo A. Collado and Gustavo Darrigran

Diversity 2024, 16(6), 357; https://doi.org/10.3390/d16060357 - 20 Jun 2024

Viewed by 592

The reproductive cycle of non-native species is indicative of their capacity for dispersal, invasion, and competition, and the alteration in biodiversity. Corbicula spp. are successful invaders of aquatic ecosystems. We studied the reproductive cycle of Corbicula largillierti from a Pampean stream, Argentina, at [...] Read more.

The reproductive cycle of non-native species is indicative of their capacity for dispersal, invasion, and competition, and the alteration in biodiversity. Corbicula spp. are successful invaders of aquatic ecosystems. We studied the reproductive cycle of Corbicula largillierti from a Pampean stream, Argentina, at its southern distribution in South America. Specimens were collected monthly from January 2003 to April 2005 and processed using traditional histological techniques. Three gonadal stages (active gametogenesis, mature, and spawned) were recognized. In the studied population, most individuals were hermaphroditic with a dominant female gonadal portion. The three gonadal stages were observed during the whole sampling period with rapid gonadal recovery; no resting period was observed. Five oocyte spawning events were recognized, occurring in autumn and spring. Expanding the knowledge of reproductive features of the Corbicula largillierti allows the understanding of current distributions. The results highlight the difficulty of identifying patterns of gamete release and spawning behavior in this invasive species, as it is recorded for other Corbicula spp. Full article

(This article belongs to the Section Animal Diversity)

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16 pages, 881 KiB

Open AccessArticle

Experiments Reveal That Search Image Might Be Responsible for Seasonal Variation in Nest-Predation Rates

by Magne Husby and Turid Verdal

Diversity 2024, 16(6), 356; https://doi.org/10.3390/d16060356 - 20 Jun 2024

Viewed by 715

Abstract

Investigations of seasonal variations in nest predation rates yield highly variable results. Some investigations argue that search image is responsible for some of the nest-predation patterns, but as far as we know, this study is the first in which search image in connection [...] Read more.

Investigations of seasonal variations in nest predation rates yield highly variable results. Some investigations argue that search image is responsible for some of the nest-predation patterns, but as far as we know, this study is the first in which search image in connection with seasonal variation in nest-predation rate has been experimentally tested. We used 1457 artificial nests placed in an identical way during the months of March to August, either in the two months consecutively or early and late within one of the two months, between the years 2000 and 2023. In addition, we compared the change in nest-predation rates at 113 artificial and 460 natural nests between the same two months. We estimated the seasonal variation in the abundance of breeding birds in the study area with 140 point counts to find the abundance of different species at the times when they normally breed. We found a strong and consistent seasonal variation in the nest-predation rate, with the highest predation rate in the middle of the breeding season. There was a similar change in the predation rate on natural and artificial nests between May and June. From July to August, the predation rate on artificial nests decreased significantly, while the search-image experiment revealed a significant increase between the same two months. A generalized linear mixed-effect model analysis found that the variation in nest-predation rates on artificial nests was significantly affected by seasonal variation in the estimated number of natural nests, that nests in trees were predated more often than nests on the ground, and that nests in the open landscape and on forest edges suffered higher predation rates than nests inside a forest. Mammals were nest predators significantly more often inside forests and on forest edges than in the open landscape, but birds were much more common nest predators than mammals independent of placement and habitat. Our experiment shows that search image explains the seasonal variation in nest-predation rates. However, more investigations are needed to find the reasons for the variation in published results on seasonal variation. Further, experimental testing on search image to find its contribution to the seasonal variation in nest-predation rates in other areas is also needed. Full article

(This article belongs to the Collection Feature Papers in Animal Diversity)

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15 pages, 1561 KiB

Open AccessArticle

Implications of Ecological Drivers on Roan Antelope Populations in Mokala National Park, South Africa

by Nkabeng Thato Maruping-Mzileni, Hugo Bezuidenhout, Sam Ferreira, Abel Ramoelo, Morena Mapuru, Lufuno Munyai and Roxanne Erusan

Diversity 2024, 16(6), 355; https://doi.org/10.3390/d16060355 - 19 Jun 2024

Viewed by 497

Abstract

Climate change has massive global impacts and affects a wide range of species. Threatened species such as the roan antelope (Hippotragus equinus) are particularly vulnerable to these changes because of their ecological requirements. Attempts to address concerns about the roan’s vulnerability [...] Read more.

Climate change has massive global impacts and affects a wide range of species. Threatened species such as the roan antelope (Hippotragus equinus) are particularly vulnerable to these changes because of their ecological requirements. Attempts to address concerns about the roan’s vulnerability have not been well documented in South African protected areas. This study identifies the landscape use and distribution of the roan as well as habitat and forage suitability changes to help inform management decisions for the conservation of roan. We used fine- and broad-scale data from Mokala National Park, South Africa that includes roan occurrence data, vegetation condition indices, vegetation (structure and plant species composition), elevation and temperature differences, and precipitation strata to construct a suitability framework using the Maximum Entropy (Maxent) and Random Forest statistical package. In Mokala National Park, roan occurred in the Schmidtia pappophoroides–Vachellia erioloba sparse woodland, Senegalia mellifera–Vachellia erioloba closed woodland, Senegalia mellifera–Vachellia tortilis open shrubland, Vachellia erioloba–V. tortilis closed woodland and Rhigozum obovatum–Senegalia mellifera open shrubland. The veld (vegetation) condition index (VCI) improved from 2019 (VCI < 50%) to 2021 (VCI > 60%), with the proportion of palatable grass species (Schmidtia pappophoroides and Eragrostis lehmanniana) also increasing. This study identified four key climatic conditions affecting roan distribution, namely annual mean daily temperature range, temperature seasonality, minimum temperatures of the coldest month, and precipitation of the wettest month. These results suggest that the conservation of roan antelope should consider these key variables that affect their survival in preferred habitats and foraging areas in anticipation of changing ecological conditions. Full article

(This article belongs to the Special Issue Biodiversity in Arid Ecosystems)

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14 pages, 4380 KiB

Open AccessArticle

Soil–Plant–Pollinator Relationships in Urban Grass and Meadow Habitats: Competing Benefits and Demands of Tall Flowering Plants on Soil and Pollinator Diversity

by Will Rust, Madison Sotkewicz, Zhaoxing Li, Theresa Mercer and Alice S. Johnston

Diversity 2024, 16(6), 354; https://doi.org/10.3390/d16060354 - 19 Jun 2024

Viewed by 344

Abstract

Urban green spaces can be important habitats for soil, plant, and pollinator diversity and the complementary ecosystem functions they confer. Most studies tend to investigate the relationships between plant diversity with either soil or pollinator diversity, but establishing their relationship across habitat types [...] Read more.

Urban green spaces can be important habitats for soil, plant, and pollinator diversity and the complementary ecosystem functions they confer. Most studies tend to investigate the relationships between plant diversity with either soil or pollinator diversity, but establishing their relationship across habitat types could be important for optimising ecosystem service provision via alternative management (for instance, urban meadows in place of short amenity grass). Here, we investigate soil–plant–pollinator relationships across urban grass and meadow habitats through a range of measured biodiversity (soil mesofauna and macrofauna, plants, aboveground invertebrates, and pollinators) and edaphic variables. We found significant effects of habitat type on available nutrients (plant and soil C:N ratios) but less clear relationships were observed between habitat type and diversity metrics. Soil–plant–pollinator interactions across habitat types and sites showed an interconnection, whereby flowering plant abundance increased alongside soil macrofauna abundance. Site characteristics that showed strong effects on plant and invertebrate diversity metrics were C:N ratios (plant and soil) and soil pH, suggesting a potential role of nutrient availability on soil–plant–pollinator associations. Our results suggest that a combination of short-mown grass, tall grass, and sown flowers can provide greater benefits for soil and pollination services as each habitat type benefits different taxa due to differing sensitivities to management practices. For example, pollinators benefit from sown flowers but soil fauna are sensitive to annual sowing. Our results also indicate that sown flowers may not optimise overall biodiversity as expected due to disturbance and the depleting role of tall, flowering plants on soil nutrient availability. Future research across a greater range of sites in urban landscapes would resolve the potential role of nutrient availability in modulating soil–plant–pollinator interactions in urban green spaces. Full article

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2 pages, 156 KiB

Open AccessCorrection

Correction: Toro-Ospina et al. Genetic Architecture and Signatures of Selection in the Caqueteño Creole (Colombian Native Cattle). Diversity 2022, 14, 828

by Alejandra M. Toro-Ospina, Ana C. Herrera Rios, Wellington Bizarria Santos, Gustavo Pimenta Schettini, Viviana H. Vallejo Aristizabal, Gilberto Tovar Claros and Edna Gicela Ortiz Morea

Diversity 2024, 16(6), 353; https://doi.org/10.3390/d16060353 - 19 Jun 2024

Viewed by 184

Abstract

Missing Citation [...] Full article

(This article belongs to the Section Animal Diversity)

21 pages, 329 KiB

Open AccessArticle

The Relationship between Grinnellian and Eltonian Niche Characteristics and Passerine Distribution across a Latitudinal Gradient

by Erin E. Stukenholtz and Richard D. Stevens

Diversity 2024, 16(6), 352; https://doi.org/10.3390/d16060352 - 18 Jun 2024

Viewed by 961

Abstract

The degree to which Grinnellian and Eltonian niche characteristics influence species distribution may depend on latitude. Tropical regions are environmentally stable and resource-rich, whereas temperate regions are comparatively less environmentally stable (e.g., environmental filtering). Moreover, phylogenetic niche conservatism could influence distributions by inhibiting [...] Read more.

The degree to which Grinnellian and Eltonian niche characteristics influence species distribution may depend on latitude. Tropical regions are environmentally stable and resource-rich, whereas temperate regions are comparatively less environmentally stable (e.g., environmental filtering). Moreover, phylogenetic niche conservatism could influence distributions by inhibiting the ability for species to colonize environmentally different locations. Herein, we examine relationships between niche characteristics, passerine distributions, and phylogenetic niche conservatism across the latitudinal gradient. We used environmental and climatic variables to characterize Grinnellian niches and diets to characterize Eltonian niches. We conducted variation partitioning with retained components from ordination methods to evaluate the degree of association of Grinnellian and Eltonian niche characteristics with passerine distribution across latitudes. We examined the relationship between phylogenetic signal and niche characteristics with a phylogenetic regression. Passerine distributions were more related to environmental gradients than resources across latitudes. While niche conservatism was prevalent in Eltonian niche characteristics, phylogeny was related to Grinnellian niche characteristics in only 46% of biomes. There was no latitudinal gradient in phylogenetic niche conservatism or the degree to which Eltonian and Grinnellian niche characteristics relate to passerine distribution. Niche conservatism, albeit weak, was present for Grinnellian niche characteristics, thus potentially influencing the expansion of passerine distributions into the northern hemisphere. Full article

(This article belongs to the Section Biogeography and Macroecology)

23 pages, 10173 KiB

Open AccessArticle

Leaf Architecture in the Morphological Diversity of the Genus Prosopis in the Semi-Desert Area of Northeastern Mexico

by Rahim Foroughbakhch Pournavab, Maginot Ngangyo Heya, Emmanuel Adan Castillo Gonzalez, Alejandra Rocha Estrada, Lidia Rosaura Salas Cruz and Marco Antonio Alvarado Vázquez

Diversity 2024, 16(6), 351; https://doi.org/10.3390/d16060351 - 17 Jun 2024

Viewed by 416

Abstract

Mesquite (Prosopis spp.) is one of the main plant representatives in regions with a dry climate, and is a fundamental part of the flora of the Mexican arid, with an indisputable importance from ecological, economic and industrial points of view. However, the [...] Read more.

Mesquite (Prosopis spp.) is one of the main plant representatives in regions with a dry climate, and is a fundamental part of the flora of the Mexican arid, with an indisputable importance from ecological, economic and industrial points of view. However, the restrictive factors of dry climates, as well as genetic variability, are sources of the great diversity of mesquite, so its taxonomy is not yet well defined. The present study seeks to determine the diversity of mesquite in the Mexican semi-desert based on the morphometric characterization of its leaves. Methods: Different leaf parameters such as the number, length and width of the leaflets were recorded in 31 well-marked sites in the area, to obtain measures of central tendency and dispersion, and to determine the differences and similarities between the sites, as well as the groups of homogeneous and heterogeneous taxa. Results: Five taxa were identified, of which there were two varieties (Prosopis glandulosa var. glandulosa and Prosopis reptans var. cinerascens), a pure or typical species (Prosopis laevigata) and two hybrids (Prosopis glandulosa var. glandulosa x Prosopis laevigata and Prosopis laevigata x Prosopis glandulosa var. glandulosa). The discriminant analysis indicated that five variables presented the highest percentage of separation or best separated the taxa, so the study was based on the phenogram with the combination of these five variables: (a) length of middle leaflets, (b) length of upper leaflets, (c) spacing of middle leaflets, (d) length/width relationship of middle leaflets and (e) length/width relationship of middle leaflets. Conclusions: Both the traditional taxonomic classification and the cluster and discriminant analyses reflected the same taxa (Prosopis glandulosa var. glandulosa, Prosopis laevigata and Prosopis reptans var. cinerascens) and the existence of hybridization between Prosopis glandulosa var. glandulosa and Prosopis laevigata. Full article

(This article belongs to the Special Issue Ecology and Diversity of Plants in Arid and Semi-arid Ecosystems)

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16 pages, 6211 KiB

Open AccessArticle

Drivers for the Diversity of Mollusc Communities in Unique Calcareous Fen Habitats

by Iga Lewin, Adam Tarkowski, Piotr Sugier, Wojciech Płaska, Edyta Buczyńska and Paweł Buczyński

Diversity 2024, 16(6), 350; https://doi.org/10.3390/d16060350 - 17 Jun 2024

Viewed by 495

Abstract

The research was carried out in calcareous fen habitats which share coverage with Natura 2000 sites designated under the EU Habitats and the Birds Directive. A total of 27 taxa of molluscs were recorded: 23 gastropod and 4 bivalve species. Anisus vorticulus, [...] Read more.

The research was carried out in calcareous fen habitats which share coverage with Natura 2000 sites designated under the EU Habitats and the Birds Directive. A total of 27 taxa of molluscs were recorded: 23 gastropod and 4 bivalve species. Anisus vorticulus, one of the species of Community interest whose conservation requires designation of special conservation areas within the Habitats Directive Natura 2000, was subrecedent and accedent in mollusc communities. Calcareous fen habitats offer the aquatic organisms harsh environmental conditions including a relatively high temperature of the water up to 33.29 °C (undrained fens), oxygen deficits in the water, high pH of up to 11.08 (fen pools) and conductivity above 3000 μS cm⁻¹ (fen ditches). Therefore molluscs have to face extreme environmental conditions. Temperature of the water, pH, dissolved oxygen and conductivity were the parameters most associated with the distribution of mollusc species in the calcareous fen habitats. The abundance of submerged and floating macrophytes, the degree of habitat persistence and the fish predation pressure on molluscs also exerted a significant effect on their distribution. The calcareous fen habitats that are listed in Annex I of the European Union Habitats Directive create a unique valuable ecosystem that contributes to the natural diversity of aquatic organisms. Full article

(This article belongs to the Section Freshwater Biodiversity)

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12 pages, 6664 KiB

Open AccessArticle

Bone Connectivity and the Evolution of Ichthyosaur Fins

by Marta S. Fernández, Lisandro Campos, Agustina Manzo and Evangelos Vlachos

Diversity 2024, 16(6), 349; https://doi.org/10.3390/d16060349 - 17 Jun 2024

Viewed by 1553

Abstract

After the end-Triassic extinction, parvipelvian ichthyosaurs diversified and became dominant elements of marine ecosystems worldwide. By the Early Jurassic, they achieved a thunniform body plan that persisted for the last 100 m.y.a of their evolution. Diversification and extinctions of thunniform ichthyosaurs, and their [...] Read more.

After the end-Triassic extinction, parvipelvian ichthyosaurs diversified and became dominant elements of marine ecosystems worldwide. By the Early Jurassic, they achieved a thunniform body plan that persisted for the last 100 m.y.a of their evolution. Diversification and extinctions of thunniform ichthyosaurs, and their swimming performance, have been studied from different perspectives. The transformation of limbs into hydrofoil-like structures for better control and stability during swimming predates thunniform locomotion. Despite their importance as control surfaces, fin evolution among thunnosaurs remains poorly understood. We explore ichthyosaur fin diversity using anatomical networks. Our results indicate that, under a common hydrofoil controller fin, the bone arrangement diversity of the ichthyosaur fin was greater than traditionally assumed. Changes in the connectivity pattern occurred stepwise throughout the Mesozoic. Coupled with other lines of evidence, such as the presence of a ball-and-socket joint at the leading edge of some derived Platypterygiinae, we hypothesize that fin network disparity also mirrored functional disparity likely associated with different capabilities of refined maneuvering. The ball-and-socket articulation indicates that this local point could be acting like a multiaxial intrafin joint changing the angle of attack and thus affecting the maneuverability, similar to the alula of flying birds. Further studies on large samples and quantitative experimental approaches would be worthy to test this hypothesis. Full article

(This article belongs to the Special Issue Making New Out of the Old: Recent Biological Advances on Mesozoic Marine Reptiles)

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16 pages, 1982 KiB

Open AccessArticle

Maxent Predictive Species Distribution Models and Model Accuracy Assessment for Two Species of Psilochalcis Kieffer (Hymenoptera: Chalcididae) Occurring in the Eastern Great Basin of Utah, USA

by Mark J. Petersen, Hector G. Ortiz Cano, Teresa Gomez, Robert L. Johnson, Val Jo Anderson and Steven L. Petersen

Diversity 2024, 16(6), 348; https://doi.org/10.3390/d16060348 - 16 Jun 2024

Viewed by 423

Abstract

Two species of Psilochalcis wasps (P. minuta and P. quadratis) were recently described from Utah’s eastern Great Basin. The extent of their known distributions is extremely limited, based on few data points. We developed species distribution models (SDMs) using Maxent modeling [...] Read more.

Two species of Psilochalcis wasps (P. minuta and P. quadratis) were recently described from Utah’s eastern Great Basin. The extent of their known distributions is extremely limited, based on few data points. We developed species distribution models (SDMs) using Maxent modeling software for each Psilochalcis species to identify areas of probable suitable habitat for targeted collecting to improve our knowledge of their distributions. We used six occurrence data points for P. minuta and eight occurrence data points for P. quadratis, along with ten environmental variables as inputs into the Maxent modeling software. Model-predicted areas with a potential suitable habitat value greater than 0.69 were mapped using ArcGIS Pro to help select locations for model accuracy assessment. Employing Malaise traps, eighteen sites were sampled to evaluate each SDM’s ability to predict the occurrence of Psilochalcis species. Psilochalcis minuta occurred at eight of nine juniper-dominated sample sites that were predicted as having high suitability by the model for this species. Likewise, P. quadratis occurred at two of four cheatgrass-dominated sample sites predicted by the model. Psilochalcis minuta occurred at three of nine sampled sites that were not predicted by the model, and P. quadratis occurred at seven of fourteen non-predicted sites. The Maxent SDM results yielded an AUC value of 0.70 and p-value of 0.02 for P. minuta and 0.68 and 0.02. for P. quadratis. These results were reflected in our model accuracy assessment. Of the selected environmental variables, aspect, historic fire disturbance, and elevation yielded the greatest percent contributions to both species’ models. Sympatric distributions were observed for P. minuta and P. quadratis. Elevation, vegetation type, NDVI, and soil type are the most important environmental variables in differentiating areas of optimal suitable habitat for the two species. Full article

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13 pages, 1152 KiB

Open AccessArticle

Conservation Prioritization of Orthoptera Assemblages on a Mediterranean Island

by Elli Tzirkalli, Konstantina Zografou, Luc Willemse, Ioannis N. Vogiatzakis and Vassiliki Kati

Diversity 2024, 16(6), 347; https://doi.org/10.3390/d16060347 - 15 Jun 2024

Viewed by 426

Abstract

In response to the ongoing global extinction, conservationists must prioritize future conservation investments to ensure that such measures are biologically effective and economically viable. To propose an effective conservation plan for Orthoptera assemblages on Cyprus Island, we introduce the Standardized Conservation Index ( [...] Read more.

In response to the ongoing global extinction, conservationists must prioritize future conservation investments to ensure that such measures are biologically effective and economically viable. To propose an effective conservation plan for Orthoptera assemblages on Cyprus Island, we introduce the Standardized Conservation Index (StCI), a biodiversity index accounting for the conservation value (c_i), presence, dispersal ability, endemism and conservation status of a species. We evaluated the effect of eleven environmental variables on StCI, c_i, species richness and the Shannon–Wiener diversity index, using linear and generalized linear models. Species and environmental data were collected in 60 localities that were placed along four elevational zones and included seven habitat types. Our results revealed the importance of rural mosaics and forests for the conservation of Orthoptera. The Shannon–Wiener diversity index failed to show the importance of high-altitude forests. The Orthoptera species diversity was favored by flower heads and the soil humidity, while rock cover and high shrubs had a positive and negative effect, respectively, on the StCI and c_i values. Our results underline the value of StCI in complementing traditional diversity indices, as a scale-independent index that can be used for different taxa to prioritize sites of conservation concern. Full article

(This article belongs to the Special Issue Biodiversity Conservation Planning and Assessment)

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15 pages, 8144 KiB

Open AccessArticle

The Complete Mitogenomes of Two Species of Snakehead Fish (Perciformes: Channidae): Genome Characterization and Phylogenetic Analysis

by Tangjun Xu, Wenwen Zhang, Yao Li, Jiachen Wang, Yawen Bai and Hongyi Liu

Diversity 2024, 16(6), 346; https://doi.org/10.3390/d16060346 - 14 Jun 2024

Viewed by 376

Abstract

Channidae (snakehead fish) is a family of medium-to-large freshwater carnivorous fish and contain the genus, Channa. Here, the complete mitogenomes of two Channa fish were determined and comparatively analyzed with the mitogenomes of 16 other Channidae fish species. The two newly sequenced [...] Read more.

Channidae (snakehead fish) is a family of medium-to-large freshwater carnivorous fish and contain the genus, Channa. Here, the complete mitogenomes of two Channa fish were determined and comparatively analyzed with the mitogenomes of 16 other Channidae fish species. The two newly sequenced complete mitogenomes were circular DNA molecules with sizes of 16,953 bp (Channa burmanica; OP954106) and 16,897 bp (Channa aurantimaculata; OQ134162). The mitogenomes were composed of 37 genes and one D-loop region. Positive AT skews and negative GC skews were found in the mitogenomes. Most protein-coding genes (PCGs) started with the conventional start codon, ATG; however, the sequence of the stop codon was variable. There was no obvious difference in relative synonymous codon usage among the two mitogenomes, and the two species shared a similar number of codon usage of mitogenomic PCGs, which was also similar to the mean values for the other 15 species of Channa. All Ka/Ks values were <1; cox1 had the lowest value, and atp8 had the highest. All of the tRNAs were typical clover structures, except trnS1. Phylogenetic analysis showed that C. burmanica and C. aurantimaculata shared a close relationship and that they were also closely related to C. gachua. These findings enrich the gene database of Channidae species, clarify the mitochondrial genome structure of the two species, and provide basic data for invasive biological surveillance in the future. Full article

(This article belongs to the Special Issue Generation of Genome-Wide Genetic Data and Evolutionary Analyses)

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18 pages, 6709 KiB

Open AccessArticle

Four New Sudanonautes Species of Freshwater Crabs (Crustacea: Decapoda: Potamonautidae) from Cameroon, Central Africa

by Pierre A. Mvogo Ndongo, Paul F. Clark, Thomas von Rintelen and Neil Cumberlidge

Diversity 2024, 16(6), 345; https://doi.org/10.3390/d16060345 - 14 Jun 2024

Viewed by 586

Abstract

Four new species of freshwater crab are described from material collected in northern and southwestern Cameroon and assigned to Sudanonautes Bott, 1955. Sudanonautes cameroonensis sp. n., S. eyimba sp. n., S. ngaoundere sp. n. and S. nkam [...] Read more.

Four new species of freshwater crab are described from material collected in northern and southwestern Cameroon and assigned to Sudanonautes Bott, 1955. Sudanonautes cameroonensis sp. n., S. eyimba sp. n., S. ngaoundere sp. n. and S. nkam sp. n., are distinguished by characters of the carapace, thoracic sternum, chelipeds, mandibles, adult male gonopods, and in addition by genetic analyses using the mitochondrial CO1 and 16S rRNA genes. Diagnoses, illustrations, and a phylogenetic tree based on mtDNA sequences are provided, as well as a discussion of the threats and conservation of all species. Full article

(This article belongs to the Special Issue Taxonomy, Systematics, Evolution and Biogeography of Freshwater Decapod Crustaceans)

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25 pages, 6489 KiB

Open AccessArticle

Spatio-Temporal Structure of Two Seaweeds Communities in Campeche, Mexico

by Cynthia Mariana Hernández-Casas, Ángela Catalina Mendoza-González, Deisy Yazmín García-López and Luz Elena Mateo-Cid

Diversity 2024, 16(6), 344; https://doi.org/10.3390/d16060344 - 14 Jun 2024

Viewed by 365

Abstract

Macroalgae populations are influenced by various factors that define their spatial and temporal distribution in different habitats and regions. In Mexico, studies addressing the abundance and diversity of macroalgae communities related to environmental factors are scarce. The objective is to determine the spatio-temporal [...] Read more.

Macroalgae populations are influenced by various factors that define their spatial and temporal distribution in different habitats and regions. In Mexico, studies addressing the abundance and diversity of macroalgae communities related to environmental factors are scarce. The objective is to determine the spatio-temporal variation of the structure of the community of seaweeds in Xpicob and Villamar, Campeche, during three climatic seasons. Sampling took place during each season using transects and quadrants; additionally, the type of substrate, water temperature, transparency, depth, salinity, and dissolved oxygen, were recorded. The total richness was 74 taxa, corresponding to three classes: Phaeophyceae (3), Florideophyceae (36), and Ulvophyceae (35). Filamentous algae dominate in species richness in the intertidal zone at low depths, while fleshy and calcareous algae predominate in number and biomass in the subtidal zone at higher depths (60–200 cm). Twenty-eight species were common to both sites; meanwhile, 46 taxa were exclusive of specific sites, including 13 found exclusively in Xpicob and 33 in Villamar. The most favorable climatic season for the macroalgae located in Xpicob was the winter rain. For the macroalgae community in Villamar, the most favorable climatic season was the dry. These differences are likely attributed to the predominant environmental and physicochemical characteristics of each site. Full article

(This article belongs to the Special Issue Ecology and Biogeography of Marine Benthos)

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15 pages, 4720 KiB

Open AccessArticle

Disentangling the Effects of Climate and Land Uses on Small Mammals in Agroecosystems of NE Spain

by Ignasi Torre, Andrés Requejo, Antoni Arrizabalaga and Jordi Baucells

Diversity 2024, 16(6), 343; https://doi.org/10.3390/d16060343 - 13 Jun 2024

Viewed by 359

Abstract

We analyzed the two main drivers (climate and land uses) shaping the composition of small mammal communities at 16 localities situated in the confluence of the Mediterranean and Eurosiberian regions (Barcelona, Spain). The study area represents a land use and land cover gradient [...] Read more.

We analyzed the two main drivers (climate and land uses) shaping the composition of small mammal communities at 16 localities situated in the confluence of the Mediterranean and Eurosiberian regions (Barcelona, Spain). The study area represents a land use and land cover gradient showing urbanization and crop intensification in the lowlands and forest encroachment in mountain areas. We identified 2458 small mammal individuals of 12 different species from barn owl (Tyto alba) pellets. Three open-land species (Microtus duodecimcostatus, Crocidura russula, and Mus spretus) and one forest/generalist species (Apodemus sylvaticus) were dominant in the diet, accounting for 93% of prey. In order to disentangle the effects of both main drivers on the small mammal community, we used partial constrained ordination techniques, which allowed us to determine the pure effects (and shared effects) of the environmental factors. Land use predictors explained 33.4% of the variance (mostly crops), followed by 23.4% of the variance explained by the geo-climatic variables (mostly rainfall), and an additional 24.8% of the variance was shared by both groups of predictors, totaling 81.6% of environmental variance. The remaining 18.4% of variance was unexplained by environmental matrices. This pattern was consistent with expected associations of species and biotic influences at small spatial scales and highlighted that the number of species increased from the crops in the lowlands towards the highlands covered by deciduous and coniferous forests. Full article

(This article belongs to the Special Issue 2024 Feature Papers by Diversity’s Editorial Board Members)

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12 pages, 6785 KiB

Open AccessArticle

Bryophytes Collection of the University of Brasilia Herbarium, Brazil

by Mel C. Camelo, Allan L. A. Faria, Daniela Cemin, Paulo E. A. S. Câmara and Micheline Carvalho-Silva

Diversity 2024, 16(6), 342; https://doi.org/10.3390/d16060342 - 13 Jun 2024

Viewed by 460

Abstract

The UB Herbarium, located in the Department of Botany at the University of Brasilia (Brasilia, Brazil), was established in 1963. It is the third-largest herbarium in Brazil, housing approximately 277,000 samples. This study presents a quantitative description of the bryophytes collection at the [...] Read more.

The UB Herbarium, located in the Department of Botany at the University of Brasilia (Brasilia, Brazil), was established in 1963. It is the third-largest herbarium in Brazil, housing approximately 277,000 samples. This study presents a quantitative description of the bryophytes collection at the UB Herbarium, which is the second-largest bryophytes collection in Brazil. It contains 31,099 samples, including specimens from all continents and 79 countries, with a focus on specimens from Brazil, Papua New Guinea, Malaysia, the United States, Chile, Indonesia, South Africa, Ireland, Argentina, and Sweden, as well as various islands and archipelagos. The collection has grown significantly since its creation in 1963, when it initially held 869 specimens; it now contains 31,099 specimens, which is a 59.3% increase. The herbarium holds 95 types of bryophytes. These results were gathered from consultations in the UB Herbarium online database and compiled into an Excel spreadsheet. These findings highlight the importance of our collection, making it a valuable resource for students and researchers interested in exploring and studying a diverse array of specimens. Full article

(This article belongs to the Special Issue Herbaria: A Key Resource for Plant Diversity Exploration)

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11 pages, 17959 KiB

Open AccessInteresting Images

The Queen Is Dead, Long Live the Queen: The Vanishing of Pinna nobilis and the Onset of the Congeneric P. rudis (Mollusca: Bivalvia)

by Fernando Rubino, Giovanni Fanelli and Giuseppe Denti

Diversity 2024, 16(6), 341; https://doi.org/10.3390/d16060341 - 12 Jun 2024

Viewed by 395

Abstract

The bivalve mollusc Pinna nobilis, endemic to the Mediterranean Sea, has been vanishing since 2016 from the whole basin because of an infection by multiple pathogens that caused mass mortality events. In the Eastern Mediterranean, some small populations seem to be resistant [...] Read more.

The bivalve mollusc Pinna nobilis, endemic to the Mediterranean Sea, has been vanishing since 2016 from the whole basin because of an infection by multiple pathogens that caused mass mortality events. In the Eastern Mediterranean, some small populations seem to be resistant to the infection. These individuals could represent the only possibility for the species to recolonize desert habitats. Thus, according to the recommendations of IUCN, looking for living specimens of P. nobilis is a priority. With this goal in mind, we carried out surveys in different areas of Southern Italy, and in 2018, we launched a Citizen Science campaign to involve recreational and professional divers in this challenge. As a result of a monitoring activity carried out in 2022–2024, along the Ionian coast of Apulia, in Southern Italy, we can say that there are no more living specimens there but only empty shells. Concurrent to the vanishing of the queen P. nobilis, its congeneric P. rudis, resistant to the infection, seems to be taking advantage, becoming more common and colonizing habitats once exclusive to P. nobilis. In fact, from different areas of the Mediterranean, sightings of the new possible queen, P. rudis, are increasing, together with the discovery of individuals exhibiting morphological traits that are a mixture of the two species. In some cases, these morphological features are not easy to detect; nevertheless, the presence of these hybrids, resistant to the infection, is important for the conservation of the species. Full article

(This article belongs to the Collection Interesting Images from the Sea)

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12 pages, 674 KiB

Open AccessArticle

Reproductive Response of Platynothrus peltifer (C.L. Koch, 1839) to Continuous Nitrogen Deposition

by Marie-Charlott Petersdorf, Joren Bruggink, Evy A. de Nijs and Henk Siepel

Diversity 2024, 16(6), 340; https://doi.org/10.3390/d16060340 - 11 Jun 2024

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Abstract

Continuous nitrogen deposition threatens ecosystems by acidifying soils, causing a stoichiometric imbalance in the vegetation and ultimately, the disappearance of plant and animal species. There is a gap in knowledge of how decomposers such as oribatid mites cope with the effects of nitrogen [...] Read more.

Continuous nitrogen deposition threatens ecosystems by acidifying soils, causing a stoichiometric imbalance in the vegetation and ultimately, the disappearance of plant and animal species. There is a gap in knowledge of how decomposers such as oribatid mites cope with the effects of nitrogen deposition. Therefore, we conducted feeding experiments with the herbivorous mite Platynothrus peltifer (C.L. Koch, 1839) to assess its fitness as a measure of its reproductive response towards different nitrogen levels in its diet. Mites were collected from the field, starved, and allowed to lay eggs. We recorded the number of eggs during 60 days of experimental trial. The fecundity of mites varied with different elemental compositions, whereby phosphorus seemed to be a limiting factor. With ongoing nitrogen deposition in the future and concomitant phosphorus limitation, we expect a negative impact on the population dynamics of herbivorous decomposers such as Platynothrus peltifer. Full article

(This article belongs to the Special Issue Diversity and Ecology of the Acari)

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14 pages, 17937 KiB

Open AccessArticle

Anatolia: A Hotspot of Avian Genetic Diversity in the Western Palaearctic

by Tamer Albayrak, Tuğba Tunçel, Pınar Öğe, Dieter Thomas Tietze and Giovanni Forcina

Diversity 2024, 16(6), 339; https://doi.org/10.3390/d16060339 - 11 Jun 2024

Viewed by 542

Abstract

Located at the crossroads of two continents and at the southeastern edge of the Mediterranean Basin, Anatolia was one of the most important Pleistocene glacial refugia in the Western Palaearctic. As part of the Irano-Anatolian, Caucasus and Mediterranean Basin biodiversity hotspots, this region [...] Read more.

Located at the crossroads of two continents and at the southeastern edge of the Mediterranean Basin, Anatolia was one of the most important Pleistocene glacial refugia in the Western Palaearctic. As part of the Irano-Anatolian, Caucasus and Mediterranean Basin biodiversity hotspots, this region is also home to a rich avian community including nearly 400 breeding species. Nevertheless, research addressing the genetic structure and diversity of local bird populations is limited, and information on glacial refugia in this region is still scant, especially when compared to other large Mediterranean peninsulas, namely the Balkan, Italian and Iberian ones. In this study, we contribute to filling this gap by addressing the biogeographic pattern of four common resident songbirds—the Eurasian blue tit (Cyanistes caeruleus), the great tit (Parus major), the Eurasian chaffinch (Fringilla coelebs) and the Eurasian blackbird (Turdus merula)—and one endemic species—the Krüper’s nuthatch (Sitta krueperi)—by amplifying two mitochondrial DNA genes in individuals from Anatolia (n = 329) and comparing their sequences to those of conspecifics from the rest of their distribution range across the western Palaearctic (n = 357) deposited in public databases. The overall genetic structure of these species is consistent with a scenario of isolation for multiple populations in different refugia across Anatolia and subsequent secondary contact in the wake of ice retreat, which makes this region a hotspot of genetic diversity for both widespread and endemic avian species. Full article

(This article belongs to the Special Issue Selected Papers from International Eurasian Ornithology Congress (IEOC 2023))

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25 pages, 11779 KiB

Open AccessArticle

Benthic Diatoms on Macrophytes of the Israeli Mediterranean Coast

by Sophia Barinova, Larisa Ryabushko, Daria Balycheva, Anastasiia Blaginina, Elena Chiernyavsky and Armine Shiroyan

Diversity 2024, 16(6), 338; https://doi.org/10.3390/d16060338 - 11 Jun 2024

Viewed by 1484

Abstract

Benthic diatoms have been studied in different areas of the Mediterranean Sea, but no data have been available for Israeli coastal waters until the present time. In this work, the composition, ecology, and phytogeography of diatoms of the macrophytes epiphyton are presented for [...] Read more.

Benthic diatoms have been studied in different areas of the Mediterranean Sea, but no data have been available for Israeli coastal waters until the present time. In this work, the composition, ecology, and phytogeography of diatoms of the macrophytes epiphyton are presented for the first time. Altogether, 85 diatom taxa were found among the epiphyton of 25 species of green, brown, and red macroalgae from the Israeli coast between March and May of 2021. These diatoms represent three classes, 17 orders, 26 families, and 41 genera. The taxonomic composition, ecology, and phytogeography of species are discussed. The distribution of diatoms are compared to that of other macrophytes and anthropogenic loads across the shoreline. The dominant species are given. Ecological characteristics and abundance in communities of revealed species are represented and statistically analyzed. The index of saprobity S varies between 1.69–2.71. Sites that stressed aquatic communities are indicated. The influence of the anthropogenic loads on the coastal territories is defined as a major factor that stimulated diatom species richness. Sites with anthropogenic stress for aquatic communities are indicated. Based on the composition of bioindicators, it is concluded that the section of the Israeli coast studied is oligo-mesotrophic compared to the eutrophic Gulf of Tartus. Full article

(This article belongs to the Special Issue Biodiversity and Ecology in the Mediterranean Sea)

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14 pages, 5183 KiB

Open AccessArticle

BBS Gene Expression and Its Diversity in the Genus Dendrobium

by Tomoko Takamiya, Manako Saito, Aoi Miyamoto, Mio Oikawa, Liyue Zhang, Kazuki Yanagihashi, Erika Okawa, Yuuka Takahashi, Yui Suzuki, Misaki Watanabe, Tadahiro Yahagi, Keiichi Matsuzaki, Hiroshi Iijima, Tomohisha Yukawa and Yuki Ogura-Tsujita

Diversity 2024, 16(6), 337; https://doi.org/10.3390/d16060337 - 7 Jun 2024

Viewed by 379

Abstract

Dendrobium officinale Kimura & Migo in the genus Dendrobium of Orchidaceae is an important medicinal plant that produces various bibenzyl and phenanthrene derivatives. In some orchids, these derivatives have been reported to increase with fungal infection. Bibenzyl biosynthesis is regulated by bibenzyl synthase (BBS). [...] Read more.

Dendrobium officinale Kimura & Migo in the genus Dendrobium of Orchidaceae is an important medicinal plant that produces various bibenzyl and phenanthrene derivatives. In some orchids, these derivatives have been reported to increase with fungal infection. Bibenzyl biosynthesis is regulated by bibenzyl synthase (BBS). Although six genes of the BBS family have been registered from D. officinale, their gene regulation mechanisms are unclear. The infection of Dendrobium with mycorrhizal fungi also reportedly increases the expression of genes involved in biosynthesis; however, the effect of mycorrhizal fungi on bibenzyl production is unknown. The present study examined the effects of three mycorrhizal fungi isolated from D. officinale on BBS gene expression and bibenzyl production over time. One of the Tulasnellaceae operational taxonomic units induced BBS gene expression and increased two representative bibenzyls, gigantol and dendrophenol, at specific time points. Furthermore, 19 BBS sequences were cloned from 12 Dendrobium species, and a phylogenetic analysis was performed. The results indicated that repeated BBS gene duplication occurred during the evolution of the genus, and further duplication occurred after speciation. These results suggest that it is possible to optimize metabolite production by selecting suitable symbiotic fungi. Full article

(This article belongs to the Special Issue Distribution and Diversity of Orchids—2nd Edition)

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17 pages, 3254 KiB

Open AccessArticle

Genetic Population Structure of Lane Snapper Lutjanus synagris (Linnaeus, 1758) in Western Atlantic: Implications for Conservation

by Mayra Núñez-Vallecillo, Iván Vera-Escalona, Antonella Rivera, Konrad Górski and Antonio Brante

Diversity 2024, 16(6), 336; https://doi.org/10.3390/d16060336 - 7 Jun 2024

Viewed by 1477

Abstract

Genetic structure and connectivity information can be used to identify biological corridors and prioritize the conservation of areas that help maintain ecosystem integrity. Some marine fish, especially those of commercial interest, have been proposed as suitable indicators to identify potential marine biological corridors [...] Read more.

Genetic structure and connectivity information can be used to identify biological corridors and prioritize the conservation of areas that help maintain ecosystem integrity. Some marine fish, especially those of commercial interest, have been proposed as suitable indicators to identify potential marine biological corridors due to their high mobility among habitats and socioeconomic importance. In this study, we assessed the genetic structure of lane snapper populations in the Honduran Caribbean to evaluate connectivity and identify potential environmental barriers. Furthermore, we evaluated the genetic characteristics of the lane snapper on a larger spatial scale, including populations across the rest of its distribution range in the western Atlantic, using mtDNA and nuDNA markers. Our results demonstrate a significant genetic diversity of lane snappers in the Honduran Caribbean. Furthermore, despite their high dispersal potential, we observed genetic structuring in lane snapper populations on a larger spatial scale, resulting in the formation of two distinct groups throughout their distribution range: group 1 from Florida, the Gulf of Mexico, Honduras, and Colombia and group 2 from Puerto Rico and Brazil. This genetic differentiation can be attributed to oceanographic barriers such as river plumes and marine currents. These findings have the potential to significantly impact marine conservation and management efforts in the region, both at local and regional scales. It is anticipated that they will not only inform but also elicit a response, driving further action towards effective conservation measures. At a local scale, we recommend that conservation efforts focus on protecting critical habitats. At a regional scale, lane snappers should be included in the management plans of existing marine protected areas necessary to ensure the long-term sustainability of the species and the marine ecosystems in which it resides. Full article

(This article belongs to the Special Issue Diversity in 2024)

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19 pages, 6273 KiB

Open AccessArticle

Reptile Biodiversity and Vulnerability in Bolivia’s Beni Department: Informing Conservation Priorities in a Neglected Frontier

by Cord B. Eversole, Randy L. Powell, Luis R. Rivas and Dennis E. Lizarro

Diversity 2024, 16(6), 335; https://doi.org/10.3390/d16060335 - 7 Jun 2024

Viewed by 535

Abstract

The Department of Beni, in the country of Bolivia, is thought to host a significant level of biodiversity as a result of its tropical, moist, and diverse climate and landscape. However, the biodiversity of Beni is also considered poorly known and understudied due [...] Read more.

The Department of Beni, in the country of Bolivia, is thought to host a significant level of biodiversity as a result of its tropical, moist, and diverse climate and landscape. However, the biodiversity of Beni is also considered poorly known and understudied due to its inaccessible landscapes, socio-economic challenges, and an overall lack of biodiversity infrastructure. This emphasizes the need for comprehensive species inventories and the development of effective conservation policies and strategies. We conducted an assessment of biodiversity, environmental vulnerability, and conservation status of reptiles documented in Beni. We identified 169 reptile species, spanning three orders and twenty-five families that have been officially documented in Beni. Utilizing the Environmental Vulnerability Score (EVS), we classified these species into high (17.8%), medium (68.1%), and low (14.2%) vulnerability categories, while IUCN categorization revealed 1.8% of reptile species in Beni are classified as vulnerable and 0.6% as near threatened. We found significant differences in ecological drivers of vulnerability among species within all categories (high, medium, low), with habitat specificity and human persecution being significantly higher for high and medium-vulnerability species. Our results demonstrate the intricate vulnerabilities of Beni’s reptiles, highlighting the need for comprehensive, species-specific conservation strategies and planning. Most importantly, our results offer a consolidated framework of information on reptile biodiversity and conservation for researchers, conservationists, and policymakers to use and build upon in the future that will facilitate the development of biodiversity infrastructure not only in the Department of Beni but throughout Bolivia and the Neotropics Full article

(This article belongs to the Special Issue Biodiversity Conservation Planning and Assessment)

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13 pages, 1190 KiB

Open AccessArticle

Tardigrades of North America: Additions to Montana’s Biodiversity Including a New Species, Platicrista loloensis nov. sp. (Parachela, Hypsibioidea, Itaquasconinae)

by Chelsea N. Scheirer, William R. Miller and Jeffrey D. Miller

Diversity 2024, 16(6), 334; https://doi.org/10.3390/d16060334 - 6 Jun 2024

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Abstract

A total of 205 tardigrades representing two orders, five families, nine genera and ten species were extracted from a moss sample (104 tardigrades) and a lichen sample (101 tardigrades) collected near Missoula, Montana, in 2016. Three of the species are new to Montana [...] Read more.

A total of 205 tardigrades representing two orders, five families, nine genera and ten species were extracted from a moss sample (104 tardigrades) and a lichen sample (101 tardigrades) collected near Missoula, Montana, in 2016. Three of the species are new to Montana and one is new to science, Platicrista loloensis nov. sp., which is distinguished by its smooth cuticle, the presence of internal cuticular bars at the base of the claws of legs II and III and a median cuticular bar between the claws of leg IV. Full article

(This article belongs to the Special Issue Investigating the Biodiversity of the Tardigrada)

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24 pages, 6684 KiB

Open AccessArticle

What Factors Determine the Natural Fruit Set of Cephalanthera longifolia and Cephalanthera rubra?

by Laurynas Taura and Zigmantas Gudžinskas

Diversity 2024, 16(6), 333; https://doi.org/10.3390/d16060333 - 6 Jun 2024

Viewed by 370

Abstract

The reproduction of rare and endangered plant species is one of the most important factors determining the stability and survival of their populations, and knowledge of the barriers to successful reproduction is essential for species conservation. Habitat loss and slow reproduction due to [...] Read more.

The reproduction of rare and endangered plant species is one of the most important factors determining the stability and survival of their populations, and knowledge of the barriers to successful reproduction is essential for species conservation. Habitat loss and slow reproduction due to low fruit set are usually considered the main threats to Cephalanthera longifolia and C. rubra (Orchidaceae). The aim of this study was to analyse the natural fruit set of these species during three consecutive years in Lithuania in the northern part of the temperate zone of Europe. Six populations of C. longifolia and three populations of C. rubra were studied each year from 2021 to 2023. During the study period, 49.3% to 54.4% of C. longifolia and 40.0% to 54.3% of C. rubra individuals produced no fruit. Over the three-year period, fruit set in individual populations of C. longifolia ranged from 5.2% to 19.5%, whereas fruit set in populations of C. rubra ranged from 4.1% to 18.8%. Significant weak or moderate correlations were found between plant height, inflorescence length and the number of flowers in the inflorescence and fruit set of both species. Flower position in the inflorescence had a significant effect on fruit set in both species, and the fruit set rate of lower flowers was higher than that of upper flowers. Significant but weak correlations were found between the fruit set and most of the environmental factors analysed. The results of this study suggest that the fruit set of C. longifolia and C. rubra is dependent on insect pollination of the flowers, which in turn is affected by habitat conditions. Full article

(This article belongs to the Section Biodiversity Conservation)

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15 pages, 968 KiB

Open AccessArticle

Trade-Off between Song Complexity and Colorfulness in Parid Birds

by Dieter Thomas Tietze and Antje Hahn

Diversity 2024, 16(6), 332; https://doi.org/10.3390/d16060332 - 5 Jun 2024

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Abstract

Passerines are the most successfully diversified bird order (around 60% of all avian species). They have developed complicated songs to defend their territories and to attract females for mating that can evolve quickly due to cultural transmission. Complex singing as well as plumage [...] Read more.

Passerines are the most successfully diversified bird order (around 60% of all avian species). They have developed complicated songs to defend their territories and to attract females for mating that can evolve quickly due to cultural transmission. Complex singing as well as plumage coloration of male birds are honest signals for potential partners and provide information about the males’ quality. To function as honest signals, both traits must be costly for the males. Of course, not all passerine species are equally clever or beautiful. Even within a single family of 50 to 70 species, relevant traits may vary considerably. Tits and chickadees (Paridae) comprise species of similar size, varying a lot in coloration and plumage pattern. The territorial songs are relatively short and simple. We investigated the relationship between song complexity and plumage coloration, taking phylogenetic relationships into account. We studied 55 out of the 64 species with 1084 song recordings retrieved from an online database. In the best model, besides colorfulness, body size had a negative impact on song complexity. Large colorful species were found to sing less complex songs. This result supports the hypothesis of a trade-off between costly traits and their likely intense signal function. This study contributes to a better understanding of how sexual selection influences the diversification of traits. In addition, we found that despite the relatively uniform size, the general negative correlation between body size and song frequency can be recovered. Some song traits are further influenced by distribution and thus by interspecific differences in climate niche. Full article

(This article belongs to the Special Issue Selected Papers from International Eurasian Ornithology Congress (IEOC 2023))

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15 pages, 1715 KiB

Open AccessArticle

Spatial, Temporal, and Interspecific Differences in Composition of Stable Isotopes in Fishes in Maryland Coastal Bays

by Chelsea Richardson, Paulinus Chigbu and Ali Ishaque

Diversity 2024, 16(6), 331; https://doi.org/10.3390/d16060331 - 4 Jun 2024

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Abstract

Carbon (δ¹³C) and nitrogen (δ¹⁵N) isotopes were used to evaluate spatial, temporal, and interspecific differences in trophic relationships of four fish species (Paralichthys dentatus, Anchoa mitchilli, Leiostomus xanthurus, and Bairdiella chrysoura) in Maryland’s coastal [...] Read more.

Carbon (δ¹³C) and nitrogen (δ¹⁵N) isotopes were used to evaluate spatial, temporal, and interspecific differences in trophic relationships of four fish species (Paralichthys dentatus, Anchoa mitchilli, Leiostomus xanthurus, and Bairdiella chrysoura) in Maryland’s coastal bays. The δ¹³C values for all species were more enriched in 2017 than in 2018, a year of higher-than-average rainfall that likely caused higher amounts of terrestrial carbon to enter the estuary. There were significant differences among species in the δ¹³C values, with L. xanthurus being the least depleted (−17.2‰ in 2017; −18.8‰ in 2018). Spatially, the δ¹³C values of the species, particularly P. dentatus and B. chrysoura, were more depleted in the northern bays, which have a higher nutrient content and receive more freshwater inflow directly from tributaries, than the southern bays. The observed δ¹³C values (−19.5 ± 0.2‰ to –17.2 ± 0.3‰), however, indicate that marine phytoplankton was the primary carbon source of the fishes. Overall, A. mitchilli was the most enriched in δ¹⁵N (13.0‰), and L. xanthurus was the most depleted (10.2‰). δ¹⁵N was more enriched in fish from the more human-impacted northern bays than in fish from the southern bays, though this might also have stemmed from the differences in the diet composition of the species in the northern and southern bays. A. mitchilli had the highest trophic level, while L. xanthurus and P. dentatus had the lowest trophic levels. Niche breadth was widest in L. xanthurus compared to the other fish species, suggesting a higher variability in diets among L. xanthurus individuals, leading to specialized diets. There was a high niche overlap between B. chrysoura, A. mitchilli, and L. xanthurus, which indicates they fed on similar prey resources. Full article

(This article belongs to the Special Issue Marine Ecosystem Functioning and Food Webs under Climate Change)

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11 pages, 1905 KiB

Open AccessArticle

The Effects of Sampling-Site Intervals on Fish Species Richness in Wadeable Rivers: A Case Study from Taizi River Basin, Northeastern China

by Mingqiao Yu, Zhao Li, Qian Zhao and Sen Ding

Diversity 2024, 16(6), 330; https://doi.org/10.3390/d16060330 - 4 Jun 2024

Viewed by 367

Abstract

Fish play an important role in river ecosystems, and the conservation of their diversity is a common goal worldwide. It is still unclear how fish monitoring programs should be developed in order to rationalize the monitoring of fish diversity in rivers. To help [...] Read more.

Fish play an important role in river ecosystems, and the conservation of their diversity is a common goal worldwide. It is still unclear how fish monitoring programs should be developed in order to rationalize the monitoring of fish diversity in rivers. To help address this issue, we conducted a comparative study of fish species richness obtained through three site-interval monitoring programs (SS1: 3 km interval scheme; SS2: 6 km interval scheme; SS3: 9 km interval scheme) in wadeable rivers in northeastern China. Here, a total of 18 fish species and 4 rare species were collected from 3 rivers. The cumulative species-richness curves showed that SS1 had the highest species richness in a single river and in the whole region, and the species richness gradually decreased with increasing site intervals. The results of the cumulative percentage of species richness indicated that SS1 and SS2 could achieve a level of 80% of potential species richness, while only SS1 could achieve a level of 90% of potential species richness in the Lanhe River (where no rare species were present). However, the results of cumulative species richness per unit of effort indicated that SS2 and SS3 had higher input-output benefits. These results suggested that rare species were more susceptible to monitoring programs and that SS2 was more advantageous in terms of obtaining species richness and cost-effectiveness. This study provides a reliable reference for river fish-monitoring program development. Full article

(This article belongs to the Special Issue Monitoring and Conservation of Aquatic Organism in the Yangtze River Basin)

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19 pages, 4875 KiB

Open AccessArticle

Macrobenthic Assemblages and the Influence of Microhabitat in a High-Mountain Lake (Northwest Italy)

by Alice Gabetti, Alessandra Maganza, Camilla Mossotto, Barbara Rizzioli, Giuseppe Esposito, Marco Bertoli, Elisabetta Pizzul, Elena Bozzetta, Marino Prearo and Paolo Pastorino

Diversity 2024, 16(6), 329; https://doi.org/10.3390/d16060329 - 3 Jun 2024

Viewed by 351

Abstract

High-mountain lakes are freshwater ecosystems situated above the tree line which are known for their remote locations and limited accessibility. These ecosystems host simplified biotic communities primarily concentrated in the littoral zone and dominated by benthic macroinvertebrates that serve as bioindicators of environmental [...] Read more.

High-mountain lakes are freshwater ecosystems situated above the tree line which are known for their remote locations and limited accessibility. These ecosystems host simplified biotic communities primarily concentrated in the littoral zone and dominated by benthic macroinvertebrates that serve as bioindicators of environmental pressures. A two-year monitoring investigation was performed in July 2022 and July 2023 at Nero Lake (Cesana Torinese, Northwest Italy). Five sites along the lakeshore were selected for sampling physicochemical water parameters and macrobenthos. All collected data were analysed to compare trends across years and within specific sites. The results revealed that Nero Lake exhibited consistent macrobenthic communities across the two years studied, but significant differences were observed in its microhabitats. This suggests that substrate type and physicochemical water parameters strongly influence community composition. Chironomidae larvae and Mollusca were the dominant species, showing distinct associations with different substrates and environmental factors from one year to another. These findings contribute to our understanding of the intricate relationships between benthic macroinvertebrates and their environments, highlighting the necessity of detailed, small-scale assessments to comprehend ecosystem dynamics and develop effective conservation strategies. Full article

(This article belongs to the Special Issue High-Mountain Lakes, Indicators of Global Change: Ecological Characterization and Environmental Pressures-2nd Edition)

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41 pages, 1934 KiB

Open AccessArticle

Changes in Population Densities and Species Richness of Pollinators in the Carpathian Basin during the Last 50 Years (Hymenoptera, Diptera, Lepidoptera)

by Attila Haris, Zsolt Józan, Ladislav Roller, Peter Šima and Sándor Tóth

Diversity 2024, 16(6), 328; https://doi.org/10.3390/d16060328 - 3 Jun 2024

Viewed by 1811

Abstract

Temporal changes in population densities and species richness of three main pollinator groups—moths and butterflies (Lepidoptera); bees, wasps and sawflies (Hymenoptera); and hoverflies, horseflies, tachinids and bee flies (Diptera)—were investigated in the Carpathian Basin. Maintaining pollinator diversity is a crucial factor for preserving [...] Read more.

Temporal changes in population densities and species richness of three main pollinator groups—moths and butterflies (Lepidoptera); bees, wasps and sawflies (Hymenoptera); and hoverflies, horseflies, tachinids and bee flies (Diptera)—were investigated in the Carpathian Basin. Maintaining pollinator diversity is a crucial factor for preserving our biodiversity and ecosystems; furthermore, several pollinator species have a strong economic role in maintaining crop and fruit cultures. Our conclusions are based on our three and four decades of faunistic surveys in various regions of the Carpathian Basin. Analyzing and comparing our data with the historical data of the last 50 years, we concluded that densities of some pollinators declined during the past decade and a half (Symphyta, hoverflies), although populations of several species of Mediterranean origin grew (Aculeata) and new species even migrated from the warmer regions. In numerous cases, this decrease was dramatic: more than 90% decline of certain butterfly species were detected. On the other hand, the composition of pollinator fauna significantly changed due to the disappearance of some mountainous or mesophile species. The main reason for the decrease in pollinator communities is due partly to climatic change and partly to anthropogenic factors. Different groups of pollinators react differently: some groups like Syrphidae, Tachinidae, most of the butterfly families and bumblebees suffered a strong decline in the last two decades; other warm-loving groups like most of Aculeata and horseflies and bee flies showed a significant increase in population densities. Our conclusion: in our region, the pollinator crisis is present but moderate; however, there is a clear sign of the gradual transition of our pollinator fauna towards the Mediterranean type. Full article

(This article belongs to the Special Issue Emerging Effects of Pollinator Loss on Biodiversity)

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