Freshwater Fauna Research Articles

Novel Aspects in Freshwater Fauna Conservation

Freshwater ecosystems, which include rivers, lakes, wetlands, springs, streams, and ponds, harbor a rich diversity of life, making them some of the most biologically productive environments on Earth. [...]

Update of the non-marine (terrestrial & freshwater) molluscs systematic inventory occurring in Santa Catarina State/ SC, Central Southern Brazil region

Introduction: The survey of the mollusc fauna (malacofauna) of a geopolitical region (State) is important from several aspects, reaching several important sectors of knowledge. So if all regions could do the same we would have within, a few years, expanded and completed the catalog of molluscs in Brazil, with much still to be added with regard to terrestrial and freshwater fauna. Objective: Updated general rеᴠiеw of the inventory of non-marine molluscs occurring in the Santa Catarina State/ SC, subtropical Central Southern portion of the Brazilian territory. Methodology: Organization of a occurring State species taxonomic checklist and their corresponding reference database, comprising the regional knowledge formally produced around the theme at least since the year 2003. Results and Conclusions: Confirmed and recorded regional total of 241 species (202 Gastropoda & 39 Bivalvia), among which at least 86 (79 Gastropoda & 7 Bivalvia) exhibit radicals synonymical (among others) changes recently reported through the global platform "MolluscaBase" and available literature of recent production, taxonomically included all in 95 genera (83 Gastropoda & 12 Bivalvia) and 40 families (35 Gastropoda & 5 Bivalvia), with aggregated additional information about their known biogeographical distribution in the territorial space of the State.

South! Phylogeography of the Antarctic fairy shrimp Branchinecta gaini and its closest Patagonian congener Branchinecta granulosa reveals a long-term association of freshwater fauna with the southern continent

AbstractBranchinecta gaini Daday, 1910 is the southernmost extant Anostracan species occurring in various localities across Maritime Antarctica. Since this region was almost completely glaciated during the Last Glacial Maximum, the identification of potential glacial refugia and the colonization sequence of freshwater habitats within Maritime Antarctica remains primary biogeographic objective for understanding the evolution of the Antarctic environment. To evaluate the history of B. gaini in Maritime Antarctica, we performed phylogeographic analyses of B. gaini and its closest Patagonian congener Branchinecta granulosa Daday, 1902. We sampled 47 populations from all three Antarctic bioregions where B. gaini occurs – South Orkney Islands, North-west and North-east Antarctic Peninsula. B. granulosa was represented by 8 populations from Patagonia. Molecular analyses of two mitochondrial (16S, COI) and one nuclear (ITS2) marker showed low overall mitochondrial variability and the ambiguous nature of ITS2 variability. The species assessment revealed insufficient genetic differentiation between B. gaini and B. granulosa to consider them two separate species. Therefore, the widely accepted idea that there is a species of Branchinecta endemic to Antarctica and sub-Antarctic islands should be omitted, and B. gaini should be synonymized with B. granulosa. Molecular clock analysis of COI for two substitution rates dated the separation of B. gaini from B. granulosa to the Pleistocene (170 – 502 ka BP and 17 – 50 ka BP, respectively). Therefore, Antarctic populations of B. gaini separated from Patagonian B. granulosa before or during the Last Glacial Maximum, indicating an older association with the southern continent than previously anticipated. The geographic distribution of haplotypes further suggests that B. gaini most likely survived at least the last glacial period in an as-yet unknown refugium in Antarctica.

Digital image processing: A new tool for morphological measurements of freshwater turtles under rehabilitation.

Freshwater fauna is facing an uphill task for survival in the Ganga Basin, India, due to a range of factors causing habitat degradation and fragmentation, necessitating conservation interventions. As part of the ongoing efforts to conserve the freshwater fauna of the Basin, we are working on rehabilitating rescued freshwater chelonians. We carry out various interventions to restore rescued individuals to an apparent state of fitness for their release in suitable natural habitats. Morphometric measurements are crucial to managing captive wild animals for assessing their growth and well-being. Measurements are made using manual methods like vernier caliper that are prone to observer error experience and require handling the specimens for extended periods. Digital imaging technology is rapidly progressing at a fast pace and with the advancement of technology. We acquired images of turtles using smartphones along with manual morphometric measurements using vernier calipers of the straight carapace length and straight carapace width. The images were subsequently processed using ImageJ, a freeware and compared with manual morphometric measurements. A significant decrease in the time spent in carrying out morphometric measurements was observed in our study. The difference in error in measurements was, however, not significant. A probable cause for this may have been the extensive experience of the personnel carrying out the measurements using vernier caliper. Digital image processing technology can cause a significant reduction in the stress of the animals exposed to handling during measurements, thereby improving their welfare. Additionally, this can be used in the field to carry out morphometric measurements of free-ranging individuals, where it is often difficult to capture individuals, and challenges are faced in obtaining permission to capture specimens.

“The absence of normal’’; is it time for a Biocontamination Index for freshwater fauna in Aotearoa-New Zealand?

“The absence of normal’’; is it time for a Biocontamination Index for freshwater fauna in Aotearoa-New Zealand?

Nationwide Tracing of Two Top Freshwater Fish Invaders in Greece Using Environmental DNA Sampling

Alien fish invasions are causing devastating impacts on native freshwater fauna; thus, rigorous, non-invasive and cost-effective biomonitoring of lotic and lentic freshwaters to design and implement appropriate prevention and control measures is now a priority. In this study, we used a species-specific qPCR eDNA assay to monitor two of the most invasive fish species (Gambusia holbrooki and Pseudorasbora parva) in 15 river basins of Greece and validated these results with conventional fish sampling as well as existing field sampling data. Our monitoring provided new records of invasive species indicating basins for rigorous future monitoring and possible eradication attempts. The eDNA proved more sensitive as a detection tool (56% detection rate) compared to conventional electrofishing (50% detection rate) for G. holbrooki. In contrast, it proved less sensitive for detecting P. parva (38% accuracy) compared to electrofishing (44% accuracy), as evident by the two locations where the eDNA failed to detect the target species. Our study illustrates the potential of the eDNA method for regular, standardised monitoring of riverine habitats for invasive fish species by local managers for early detection. Finally, we discuss the application of eDNA in management interventions for identifying invasive species’ hotspots for management prioritisation, for early detection of invaders and for the monitoring of eradication/control actions.

An analysis of threats to endangered animal taxa in California's freshwater systems

Abstract This study analysed threats to federally and State‐listed endangered and threatened animal taxa in California, United States, and how threats varied by taxa, habitat use, spatial extent, severity, geographical region and endemic status using threat categories from the International Union for Conservation of Nature (IUCN) Red List Threats Classification Scheme and information from scientific literature and reports. A majority of the taxa evaluated were associated with freshwater habitats and were endemic to California. The most threatened taxonomic groups were fish, followed by mammals and birds. The number of threats was mostly evenly distributed across the State's three geographical regions (i.e., North, Central and South), and no single region had a disproportionately high number of endangered animal taxa. Freshwater taxa were the most affected in nearly every threat category, suggesting that freshwater taxa are more threatened than their terrestrial and marine counterparts. In descending order, the most prominent threats across all taxa were habitat loss, invasive species, climate change and altered hydrology. Threats identified as high severity also tended to have a high spatial extent and vice versa. This study shows that the numerous freshwater faunas in California are disproportionately affected by threats also found in other freshwater systems and Mediterranean‐climate regions, highlighting the scope of the freshwater biodiversity crisis in California. Managing priorities to target the most pervasive threats to endangered freshwater taxa documented in this study will help safeguard freshwater biodiversity against human threats in California and beyond.

Out of the ancient lake: Multiple riverine colonizations and diversification of the freshwater snails in the genus Semisulcospira around Lake Biwa

Ancient lakes are a hotspot of biodiversity. Freshwater species often experience spectacular species radiation after colonizing lakes from riverine habitats. Therefore, the relationship between the fauna of the ancient lakes and the surrounding riverine system has a special significance in understanding their origin and evolutionary history. The study of ancient lake species often focused on the lake colonization of riverine species. In contrast, far less attention has been placed on the reverse direction: the riverine colonization of the lake species, despite its importance in disentangling their complex evolutionary history. The freshwater snails in the genus Semisulcospira involve endemic groups that radiated in the ancient Lake Biwa. Using genetics and fossil records, we inferred that the ancestors of these lake-endemic Semisulcospira snails historically colonized the riverine habitats at least three times during the Middle Pleistocene. Each colonization resulted in the formation of a new lineage that was genetically and morphologically distinct from other lineages. Further, one of these colonizations was followed by hybridization with a cosmopolitan riverine species, which potentially facilitated the population persistence of the colonizers in the new environment. Despite their complex histories, all these colonizers were currently grouped within a single species, Semisulcospira kurodai, suggesting cryptic diversity in this species. This study highlights the significance of the riverine colonizations of the lake species to fully understand the diversification history of freshwater fauna in and around the ancient lakes.

Phylogenetic structure of body shape in a diverse inland ichthyofauna

Body shape is a fundamental metric of animal diversity affecting critical behavioral and ecological dynamics and conservation status, yet previously available methods capture only a fraction of total body-shape variance. Here we use structure-from-motion (SFM) 3D photogrammetry to generate digital 3D models of adult fishes from the Lower Mississippi Basin, one of the most diverse temperate-zone freshwater faunas on Earth, and 3D geometric morphometrics to capture morphologically distinct shape variables, interpreting principal components as growth fields. The mean body shape in this fauna resembles plesiomorphic teleost fishes, and the major dimensions of body-shape disparity are similar to those of other fish faunas worldwide. Major patterns of body-shape disparity are structured by phylogeny, with nested clades occupying distinct portions of the morphospace, most of the morphospace occupied by multiple distinct clades, and one clade (Acanthomorpha) accounting for over half of the total body shape variance. In contrast to previous studies, variance in body depth (59.4%) structures overall body-shape disparity more than does length (31.1%), while width accounts for a non-trivial (9.5%) amount of the total body-shape disparity.

Fish, Freshwater, and the Promise of Biodiversity History for Indonesian Studies

Freshwater fishes abound in Indonesia. They are everywhere in the archipelago—from rice fields and irrigation canals to brackish lagoons and highland rivers. They even populate the most unassuming bodies of water. Some species are found in the remotest of volcanic lakes while others call the blackest and most acidic peat swamps their home. Every island has its habitats and every habitat has its fishes, making Indonesia one of the world’s richest centers of ichthyofauna diversity. And yet, thinking with freshwater fishes—and their biodiversity history—has been largely absent from the field of Indonesian studies. A telling example of this biological blindspot can be found in the ways in which the Cornell Modern Indonesia Project (CMIP) has produced—and continues to constitute—Indonesia as an area of study and attachment. In CMIP’s Producing Indonesia: The State of the Field of Indonesian Studies, a landmark volume published in 2014, there were twenty-seven contributions that spanned the humanities and social sciences but none that looked at the role local scientists played in knowing the archipelago’s freshwater fauna or even broader the interplay between environment and society in shaping the study of modern Indonesia. In response, this essay centers the interplay between environment and society to show how it can open up new directions for future research and interdisciplinary collaboration. In doing so, and in particular, the paper argues that the story of fish and freshwater illustrates the promise of biodiversity history for the field of Indonesian studies in the age of environmental humanities and beyond.

Contribution to the Occurrence of the Blackfly (Diptera:Similiidae) in the Palestinian Territories, West Bank

Aims: The primary objective of the study was to gather evidence regarding the presence of black fly fauna in the Palestinian environment. The research extensively examined breeding sites and habitats, as well as studied the physiochemical parameters of the water in these breeding sites. Furthermore, the study assessed the potential impacts of these insects on both humans and animals
 Study Design: A cross- sectional study.
 Place and Duration of Study: From January 2023 to August 2023, a cross-sectional survey was conducted in the West Bank-Salfit district to collect larvae and adult blackflies within the Wadi Qana protected area.
 Methodology: In January 2023, a field survey was conducted in the Wadi Qana protected area (32.12582, 34.8952) in the Salfit district to study the freshwater fauna. A total of 220 larvae individual of the Blackfly were collected from the running water in the valley. Forceps used to collect specimens and preserved in 70% ethanol, while adults of this group were examined under a dissecting microscope. The specimens were identified using various identification keys [4,9,12].
 Results: During the study period, a total of 220 larvae were collected from breeding sites in the freshwater habitats of Wadi Qana. Two subgenera of blackflies were identified in the study area: Simulium (Wilhelmia) Enderlein and Simulium (Odgamia) Enderlein. The results indicate that blackflies breed in fast-flowing freshwater habitats covered by annual aquatic plants, with dissolved oxygen levels at 10.1 mg/L, pH average 8.2 and average temperature 21.6°C.
 No significant health effects were recorded or documented in the study area, except for the nuisance caused to humans and animals by the biting of blackflies.
 In conclusion, this study marks the first record and presence of the blackfly in the Palestinian environment. Further much more research is needed to explore their fauna, biology, ecology, habitats, distribution, and medical significance.
 Conclusion: blackfly was recorded for the first time in the Palestinian environment, more study research are needed to discussed the fauna, biology, ecology, habitats, distribution and the medically important.

Spatial priorities for freshwater fish conservation in relation to protected areas

Abstract Freshwater habitats are vital for both humans and nature owing to their exceptional biodiversity and valuable ecosystem services, but they are currently facing serious threats. The designation and management of protected areas have been proposed as the most feasible way to ensure conservation objectives for the future. However, traditional approaches have not protected freshwater fauna effectively, especially freshwater fish. Previous studies have identified the most irreplaceable terrestrial places to achieve conservation goals. Here, the aim was to investigate how the present network of protected areas preserves irreplaceable rivers for freshwater fish. The irreplaceability of the world's river basins was calculated using International Union for the Conservation of Nature Red List distribution maps, considering the rarity, richness, and conservation status of their freshwater fish fauna. The overlap between irreplaceable basins and the present network of protected areas was also calculated. The results highlight the conservation significance of tropical rivers, particularly those in the Neotropics. The subset of the basins covering 30% of the most irreplaceable land surface (in line with the United Nations 30by30 target) encompasses 99% of freshwater fish species. However, protected areas do not seem to provide sufficient protection to these basins, as 89% of their surface area lies outside protected areas. Only 7% of freshwater ecoregions meet the United Nations 30by30 target. Given the context of climate change, allocating new protected areas becomes crucial in providing better survival opportunities for freshwater fish species. Despite the limitations inherent to the absence of total knowledge of freshwater fish biogeography and the irreplaceability index itself, this study identifies priority sites for their conservation that may help inform decision‐making in the future to establish more effective protected areas.

Characterization of Microplastics and Mesoplastics and Presence of Biofilms, Collected in the Gualí Wetland Cundinamarca, Colombia

Wetlands are being contaminated by housing developments, effluents, industrial areas, and poor sanitation, resulting in the presence of plastic polymers and the development of biofilms on these materials, which represent an elevated risk to freshwater fauna and flora. The objective of this study was to characterize mesoplastics and microplastics, collected in the Gualí Wetland, Colombia, as well as to verify the presence of biofilms on such polymers. Nine water samples (36 L per sample) were evaluated at three points of the wetland; the size of the particles was determined by image analysis, the type of polymer through FTIR, and the presence of biofilms by microscopy. A total of 79 items/0.135 m3 were collected, 2 macroplastic items, 53 mesoplastic items, and 24 microplastic items. The presence of fragments (70%) and pellets (41%), with transparent (40%) and white (30%) being the predominant ones, was outstanding. Among the polymers, high-density polyethylene (HDPE) dominated, followed by expanded polystyrene. The results of SEM demonstrated the presence of diatoms on the surface of the plastic polymers. Furthermore, the results showed a greater amount of HDPE mesoplastics and microplastics in the shape of fragments and pellets. In addition, the presence of biofilms on these plastic particles can increase the adsorption of contaminants, negatively affecting this ecosystem. The outcome of this study can be used to identify bacteria that reside in biofilms associated with microplastics and mesoplastics.

Fishing historical sources: a snapshot of 19th-century freshwater fauna in Spain

Historical information is needed to describe in a robust manner long-term changes in the distribution of organisms, although it is in general scarce or contained in non-scientific sources. Gazetteers (or geographical dictionaries) constitute a potential source of historical species records, which has not been accurately explored yet. The dictionary edited by Pascual Madoz between 1845 and 1850 extensively described the geography, population and socioeconomic aspects in Spain. The dictionary included abundant information on wild animals and plants, with a special focus on socioeconomically relevant species. Here, we present a database generated by collecting and georeferencing the mentions to freshwater fauna records in the Madoz, which includes 10,750 occurrence records of 39 freshwater-associated taxa from 5,472 localities. This database has been made public and usable (following FAIR criteria) in GBIF. Most of the records correspond to fish (10,201 records, 94.9% of total; 33 taxa), followed by crayfish (418 records, 3.9% of total; one species). Annelids (one taxon), amphibians (one taxon), reptiles (one taxon) and mammals (three species) sum up to 132 records (1.2% of total). The database presented here can be used to estimate the baseline ranges of many freshwater species, which should inform present-day management for the conservation and recovery of endangered species and freshwater communities.Graphical abstract

Freshwater Fauna of Invertebrates of the Northern Slopes of the Central Caucasus

Freshwater Fauna of Invertebrates of the Northern Slopes of the Central Caucasus

Pharmaceuticals and personal care products (PPCPs) in surface water and fish from three Asian countries: Species-specific bioaccumulation and potential ecological risks

In Asian developing countries, undeveloped and ineffective sewer systems are causing surface water pollution by a lot of contaminants, especially pharmaceuticals and personal care products (PPCPs). Therefore, the risks for freshwater fauna need to be assessed. The present study aimed at: i) elucidating the contamination status; ii) evaluating the bioaccumulation; and iii) assessing the potential risks of PPCP residues in surface water and freshwater fish from three Asian countries. We measured 43 PPCPs in the plasma of several fish species as well as ambient water samples collected from India (Chennai and Bengaluru), Indonesia (Jakarta and Tangerang), and Vietnam (Hanoi and Hoa Binh). In addition, the validity of the existing fish blood–water partitioning model based solely on the lipophilicity of chemicals is assessed for ionizable and readily metabolizable PPCPs. When comparing bioaccumulation factors calculated from the PPCP concentrations measured in the fish and water (BAFmeasured) with bioconcentration factors predicted from their pH-dependent octanol–water partition coefficient (BCFpredicted), close values (within an order of magnitude) were observed for 58–91 % of the detected compounds. Nevertheless, up to 110 times higher plasma BAFmeasured than the BCFpredicted were found for the antihistamine chlorpheniramine in tilapia but not in other fish species. The plasma BAFmeasured values of the compound were significantly different in the three fish species (tilapia > carp > catfish), possibly due to species-specific differences in toxicokinetics (e.g., plasma protein binding and hepatic metabolism). Results of potential risk evaluation based on the PPCP concentrations measured in the fish plasma suggested that chlorpheniramine, triclosan, haloperidol, triclocarban, diclofenac, and diphenhydramine can pose potential adverse effects on wild fish. Results of potential risk evaluation based on the PPCP concentrations measured in the surface water indicated high ecological risks of carbamazepine, sulfamethoxazole, erythromycin, and triclosan on Asian freshwater ecosystems.

The evolutionary journey of freshwater crabs of the genus Potamon (Decapoda: Brachyura: Potamidae)

AimFreshwater ecosystems host a rich biodiversity, including freshwater crabs. The family Potamidae is a diverse group of freshwater crabs with a Palearctic and Oriental distribution. Specifically, the genus Potamon is found in the Middle East, Southern Europe, and Northern Africa. Potamon species are considered true freshwater crabs due to their total independence from the marine environment, which makes them idea organisms to study historical freshwater connectivity dynamics. In this study we aim to elucidate the phylogenetic relationships of the genus Potamon and discuss the historical freshwater connectivity in the Mediterranean region. MethodsHere we use up to eleven genetic markers to reconstruct a robust phylogenetic tree of the group and use Bayesian methods to time-calibrate the tree. We further use historical biogeography methods implemented in a Bayesian framework to assess the ancestral distribution ranges of the group. ResultsIn this study we generate the most complete dataset for the group, covering practically the whole distribution range of the genus. We obtained a robust phylogenetic hypothesis and evaluated the times of divergence of the group. The result of the historical biogeography shows the evolution of historical distribution ranges of species of Potamon.Main conclusions.The Mediterranean Sea is placed in a key intersection for the exchange of fauna and flora. Here we present evidence for the potential of freshwater fauna exchange, through the Mediterranean Sea after a period of desiccation and the loss of contact with the ocean. The origin of Potamon genus is found to be in Western Asia, probably Eastern Iran.

Identifying the current and future status of freshwater connectivity corridors in the Amazon Basin

AbstractThe Amazon Basin features a vast network of healthy, free‐flowing rivers, which provides habitat for the most biodiverse freshwater fauna of any basin globally. However, existing and future infrastructure developments, including dams, threaten its integrity by diminishing river connectivity, altering flows, or changing sediment regimes, which can impact freshwater species. In this study, we assess critical rivers that need to be maintained as freshwater connectivity corridors (FCCs) for selective freshwater species—long‐distance migratory fishes and turtles (both with migrations >500 km) and river dolphins. We define FCCs as river stretches of uninterrupted river connectivity that provide important riverine and floodplain habitat for long‐distance migratory and other species and that maintain associated ecosystem functions. We assessed more than 340,000 km of river, beginning with an assessment of the connectivity status of all rivers and then combining river status with models of occurrence of key species to map where FCCs occur and how they could be affected under a scenario of proposed dams. We identified that in 2019, 16 of 26 very long (>1000 km) rivers are free‐flowing but only 9 would remain free‐flowing if all proposed dams are built. Among long and very long rivers (>500 km), 93 are considered FCCs. Under the future scenario, one‐fifth (18) of these long and very long FCCs—those that are of critical importance for long‐distance migrants and dolphins—would lose their FCC status, including the Amazon, the Negro, Marañón, Napo, Ucayali, Preto do Igapó Açu, Beni, and Uraricoera rivers. To avoid impacts of poorly sited infrastructure, we advocate for energy and water resources planning at the basin scale that evaluates alternative development options and limits development that will impact on FCCs. The results also highlight where corridors could be designated as protected from future fragmentation.

The Species Composition and Occurrence of Free-Living Flatworms (Plathelminthes) in the Freshwater Fauna of the Middle Volga Region

The Species Composition and Occurrence of Free-Living Flatworms (Plathelminthes) in the Freshwater Fauna of the Middle Volga Region

The Inland Cladocera and Copepoda Fauna in Greece

Greece is situated in the East Mediterranean region and in the Balkan peninsula, i.e., a European biodiversity hotspot with high endemism in subterranean and freshwater fauna, highlighting the need to understand its biodiversity. A literature search was undertaken to present a checklist of cladocerans and copepods based on a compilation of published and current data, from 1892 up to 2022 from inland surfaces and subterranean water bodies from different regions of Greece. For Cladocera, 80 species were recorded (9 families with 35 genera). The most diverse families were Chydoridae (20 genera with 33 species) and Daphniidae (5 genera with 27 species). For copepoda, 134 taxa were recorded, in surface water bodies (12 families with 34 genera), subterranean water bodies (7 families with 27 genera), and parasitic copepods (3 families with 3 genera). The most diverse families in surface waters were Cyclopidae (15 genera with 41 taxa) and Diaptomidae (5 genera with 17 species), while those in subterranean waters were Cyclopidae (11 genera with 35 taxa) and Canthocamptidae (6 genera with 17 taxa). More species are expected to be discovered after sampling understudied regions, especially islands, as well as water bodies such as temporary pools, swamps, ditches, puddles, and the littoral parts of lakes, while molecular studies are needed to clarify various cases of complex taxonomy.