Mollusc Species Research Articles

Prevalence of bacterial pathogens in bivalve shellfish harvested from the brackish waters of Niger Delta, Nigeria

The presence of bacterial pathogens in bivalve shellfish harvested from the marine ecosystem globally has continued to raise serious food safety concerns, thereby undermining the nutritional and health benefits derived from their consumption. Four species of bivalve shellfish: Bloody cockle (Anadara senilis), Donax clam (Donax rugosus), Knife clam (Tagelus adansonaii) and Mangrove oyster (Crassosstra gasar) harvested from the brackish waters of the Niger Delta were assessed for their bacterial pathogens. Standard methods of analysis were employed to assess microbiological hazards accumulated by shellfish species. The results of the microbiological analysis revealed that the total viable count (TVC) was lower than the recommended limit (5.7 log cfu/g) for fresh bivalve shellfish while Vibrio cholerae, Vibrio parahaemolyticus, Salmonellaspp, Shigellaspp, Listeria monocytogenes and E. coli were far above the stipulated FDA standard for molluscian shellfish. The loads of microbiological hazards in bivalve species indicated that in all the locations, Bloody cockle and Donax clam accumulated more bacterial pathogens while the samples harvested from Ibeno and Iko Town brackish waters were lower in pathogenic loads when compared to shellfish harvested from Andoni and Bonny location. The result obtained in this study is of public health importance since, it will serve as a guide towards improved processing techniques and stimulate actions towards the development of novel surveillance as well as, prevention and control strategies, that will help to reduce foodborne disease outbreaks associated with shellfish.

Checklist of the marine malacofauna of Culuccia Peninsula (NW Sardinia, Italy), with notes on relevant species.

Culuccia is a small peninsula of about 3 km2 placed in north-western Sardinia (Italy) at the margin of the Maddalena Archipelago. The marine area surrounding this Peninsula is a Special Area of Conservation, included in the European Natura 2000 Ecological Network of protected areas, but until now, no information on biodiversity of this area is available. In 2021, a research project to study both terrestrial and marine biodiversity of Culuccia has started in order to fill this gap of knowledge. This work provides the first inventory of the marine malacofauna of the coast of Culuccia. Fifteen sites were sampled seasonally for one-year by using different sampling methods and the present study shows the results from approximately 50 scientific SCUBA and free dive surveys, carried out in all main marine habitats of the studied area. In total, 259 species of molluscs were recorded along the coasts of the Culuccia Peninsula (0-25 m depth), belonging to the classes Bivalvia, Gastropoda, Polyplacophora and Scaphopoda. Amongst the four classes recorded, gastropods were the most represented (66.90%; 173 species), followed by bivalves (28.10%; 73 species), polyplacophorans (4.60%; 12 species) and scapophods (0.40%; 1 species). Notes about distribution, conservation status and ecology for some valuable species are provided, together with images of representative species, consisting mainly of in situ photographs. Additionally, the present investigation recorded the presence of four alien species, whose Mediterranean distribution was extended to north-western Sardinia.

Molecular and structural analysis of Hdh-MIRP3 and its impact on reproductive regulation in female Pacific abalone, Haliotis discus hannai

Molluscan insulin-related peptides (MIRP) play a crucial role in various biological processes, including reproduction and larval development in mollusk species. To investigate the involvement of MIRP in the ovarian development of Pacific abalone (Haliotis discus hannai), the Hdh-MIRP3 was cloned from cerebral ganglion (CG). Hdh-MIRP3 cDNA was 993 bp long, encoded a 13.22 kDa peptide, comprising 118 amino acids. Fluorescence in situ hybridization confirmed the localization of Hdh-MIRP3 in the CG and ovary. Molecular docking revealed that Hdh-MIRP3 binds to the N-terminal region of Hdh-IRP-R. Tissue expression analysis showed the highest Hdh-MIRP3 expression in the CG, followed by ovarian tissue. Hdh-MIRP3 expression was significantly upregulated in the CG and ovary during the ripe stage of seasonal ovarian development and in effective accumulative temperature conditioned abalone. Furthermore, siRNA silencing of Hdh-MIRP3 significantly downregulated the expression of four reproduction-related genes, including Hdh-GnRH, Hdh-GnRH-R, Hdh-IRP-R, and Hdh-VTG in both the CG and ovary, and Hdh-MIRP3 as well. These results indicate that Hdh-MIRP3 acts as a regulator of ovarian development in Pacific abalone. Additionally, expression analysis indicated that Hdh-MIRP3 plays a role in embryonic and larval development. Overall, the present findings elucidate the role of Hdh-MIRP3 in reproductive development in female Pacific abalone.

Monitoring arthropods under the scope of LIFE-SNAILS project: I - Santa Maria Island baseline data with implementation of the Index of Biotic Integrity.

The database we introduce is a pivotal component of the LIFE SNAILS project (Support and Naturalisation in Areas of Importance for Land Snails). This initiative is dedicated to safeguarding three endangered species of terrestrial molluscs, specifically, two snails (Oxychilusagostinhoi Martins 1981 and Leptaxisminor Backhuys, 1975) and a semi-slug (Plutoniaangulosa (Morelet, 1860)), all of which are single island endemics from Santa Maria Island and face significant threats towards their populations.In this study, we established a comprehensive database derived from a long-term arthropod monitoring campaign utilising SLAM (Sea, Land, Air, Malaise) traps. Although molluscs were not the primary focus, our findings serve as a credible proxy for evaluating the overall habitat quality for endemic invertebrates, with arthropods serving as principal indicators. From September to December of 2022, a total of 11 SLAM traps were installed and monitored monthly in eleven sites of mixed forests of Santa Maria Island. Based on the 33 available samples (11 sites x 3 sampling periods), we recorded a total of 118 taxa of arthropods (of which 94 were identified at species or subspecies level), belonging to three classes, 14 orders and 62 families. From the 94 identified taxa, a total of 21 species were endemic, 31 native non-endemic, 32 introduced and 10 indeterminate. We also provide additional information of the habitat quality (Index of Biotic Integrity), including general habitat and dominant species composition.We registered three new records to the Island, the native bug Piezodoruslituratus (Fabricius, 1794) (Hemiptera, Pentatomidae), the Azorean endemic beetle Phloeosinusgillerforsi Bright, 1987 (Coleoptera, Curculionidae) and the exotic ant Hypoponerapunctatissima (Roger, 1859) (Hymenoptera, Formicidae) and one new record for the Azores Archipelago, the native beetle Cephenniumvalidum Assing & Meybohm, 2021 (Coleoptera, Staphylinidae, Scydmaeninae).This publication not only contributes to the conservation of highly threatened endemic molluscs, through an assessment of habitat quality, based on arthropod communities and habitat description (e.g. native or exotic vegetation), but also provides an updated inventory of arthropods from Santa Maria Island.

Microbial education for marine invertebrate disease prevention in aquaculture

AbstractThe holobiont theory expands the notion of individual multicellular organisms as a community composed of a host and all its associated microorganisms. This concept has been extensively studied in the field of aquaculture, where increasing evidence has highlighted the importance of the host associated microorganisms in species fitness. Here, we focus our review on mollusc and crustacean species in which microbiota dysbiosis has recently been described in the context of various diseases, resulting in significant economic losses. Influencing the holobiont structure through the use of probiotics is a potential strategy that could improve the fitness or the robustness of cultivated species. We discuss here the possibility of developing microbiome targeted prophylactic approaches by promoting (1) methods to identify host microbial community that fosters good health status and (2) early life microbial education to favour long‐term resistance to stress or disease. This review aims to inform the aquaculture industry about potential strategies in rearing practices to mitigate diseases and economic losses.

Assessment of the health risks associated with the consumption of bivalve mollusks potentially contaminated with phycotoxins from the coastal ecosystem of the Ebrié lagoon, Côte d'Ivoire.

This work focused on assessing of the risk associated with the consumption of bivalve mollusks, potentially contaminated with phycotoxins. The studied phycotoxins are saxitoxin (STX), okadaic acid (OA), dinophysistoxins (DTXs), yessotoxins (YTXs), pectenotoxins (PTX), azaspiracids (AZAs), and domoic acid (DA). These toxins were investigated in three species of bivalve mollusks (Anadara senilis, Crassostrea gasar, and Perna perna), originating from the Ebrié lagoon. Chemical analyses were carried out by LC-MS/MS, HPLC-FLD, and HPLC-UV. The level of OA and DTXs, STX, and DA was 10.92 µg OA eq./kg, 9.6 µg STX eq./kg, and 0.17 mg DA eq./kg, respectively. The level of PTXs and AZAs was 3.3 µg PTX-2 eq./kg and 13.86 µg AZA-1 eq./kg; that of YTXs was 0.01 mg YTX eq./kg. The daily exposure dose (DED) was 0.019 µg OA eq./kg bw for OA and DTXs; 0.285 µg DA eq./kg bw for DA; 0.006 µg PTX-2 eq./kg bw for PTXs; 0.016 µg STX eq./kg bw for STX; 0.01 µg YTX eq./kg bw for YTXs; and 0.024 µg AZA-1 eq./kg bw for AZAs for the oyster Crassostrea gasar. These estimated values are lower than the acute reference dose (ARfD) of each phycotoxin recommended by the European Food Safety Agency (EFSA). The risk of harmful effects is acceptable. The absence of risk is valid only for the study period (11 months) and concerns coastal populations living near the sampling points.

High-throughput analysis using 16S rRNA gene of bacterial communities present in selected bivalves and gastropods species from Bayug Island, Iligan City, Philippines

Abstract. Albarido NA, Tabugo SR. 2024. High-throughput analysis using 16S rRNA gene of bacterial communities present in selected bivalves and gastropods species from Bayug Island, Iligan City, Philippines. Biodiversitas 25: 431-438. Seashells, which include bivalves and gastropods, have global recognition for their significant contributions to the economy, ecology, and medicine. They hold value as a food source and are highly regarded as effective biological indicators. The objective of this study is to identify the bacterial communities present in selected edible species of bivalves (Pinctada margaritifera Linnaeus, 1758 and Anadara granosa Linnaeus, 1758) and gastropods (Canarium urceus Linnaeus, 1758 and Conus stercusmuscarum Linnaeus, 1758), through high-throughput sequencing metabarcoding. Bacterial samples were collected via a swabbing technique on the surface and inside parts of selected mollusc species, which were then placed on sterilized seawater for DNA extraction. Genomic DNA was isolated from the samples, and the V3-V4 region of the 16S rRNA gene was amplified and sequenced using the Illumina MiSeq platform. Four amplicon libraries were generated, representing the two bivalve and two gastropod species in the study area. Data analysis was conducted using the Parallel Meta Suite software. Upon quality control and processing, 173,489 amplicon sequence variants (ASVs) were obtained. Within the bacterial community, the most abundant genera included Stenotrophomonas, Vibrio, Serratia, Photobacterium, and Shewanella. The assessment of alpha diversity, using the Shannon index, indicated a higher diversity in A. granosa. Furthermore, the analysis using the PICRUSt algorithm within the Parallel Meta Suite unveiled the involvement of specific bacteria found in the selected gastropod and bivalve species in various functions. These functions encompass protein production, xenobiotic metabolism, biodegradation, and other metabolism-related processes, supporting these organisms' ecological and physiological roles.

Development and Testing of Species-Specific Primers for Detecting the Presence of the Northern Pacific Sea Star (Asterias amurensis) from Environmental DNA.

The starfish Asterias amurensis, a well-known predator of molluscan species in intertidal ecosystems, has caused substantial ecological and economic losses in North China such as offshore Qingdao. Effective monitoring and prevention measures are urged to minimize its negative impacts. Compared with traditional biomonitoring methods, environmental DNA technology has emerged as a powerful and cost-efficient tool for inferring species' presence and abundance. In this study, we developed a pair of species-specific primers (i.e., Ast-F and Ast-R) for the A. amurensis mitochondrial COI gene and tested its utility in amplifying and quantifying the DNA fragments from environmental samples under both laboratory and field conditions. The results of controlled water tank experiments demonstrated that the amount of eDNA released by A. amurensis was positively related to its biomass; after the removal of the starfish, the eDNA degraded significantly in 24h and remained detectable for 8days. The number of eDNA copies enriched tended to increase with smaller pore size of filter membrane and larger volume of filtered water. For field tests, we confirmed the validation of our approach in six locations in Qingdao by filtering 1000ml water per sample with a 0.45-µm pore size filtration. All the amplification products generated a single and bright band via gel electrophoresis, and the quantitative PCR results unveiled significant differences in eDNA copies. This study provided an eDNA-based approach for investigating the distribution and biomass of A. amurensis, which may help to formulate early warning and management strategies in coastal Qingdao and other regions.

A late Oligocene molluscan fauna and Oligocene coastal outcrops from Vilsund, NW Denmark

Abstract: A rich late Oligocene molluscan fauna from a coastal cliff at Vilsund on the island of Mors, Jylland, Denmark, was studied. A summary of the upper Palaeogene sedimentary sequence in NW Jylland is given and lithostratigraphical and biostratigraphical correlations are suggested. The molluscan fauna contains 120 species, and the nonmolluscs are briefly mentioned. The new species Mitromorpha (Mitrolumna) danica n. sp. and Cerithiopsis vilsundensis n. sp. are established. Mitromorpha (Mitrolumna) danica n. sp. is the first representative of the gastropod genus Mitromorpha Carpenter, 1865 and subgenus Mitrolumna Bucquoy, Dautzenberg & Dollfus, 1883 from the Cenozoic of Denmark. Eubela (s. lat.) zetes (Kautsky, 1925) represents the oldest record of the genus Eubela Dall, 1889. Andersondrillia Schnetler & Beyer, 1990 is considered to be a junior synonym of Benthomangelia Thiele, 1925. The bivalve genus Cubiostrea Sacco, 1897 is recorded from the upper Oligocene of the North Sea Basin for the first time. In the systematical part, several species are treated, including 16 species which have not been recorded previously from the Danish upper Oligocene; a synopsis of the representatives of the genus Streptodictyon Tembrock, 1961 in the Danish Oligocene is also given. Aphanitoma ingerae Schnetler & Palm, 2008 is transferred to the genus Mitromorpha, subgenus Mitrolumna. The fauna is compared with other Danish and German late Oligocene faunas and palaeoecological interpretations are suggested. As many of the mollusc species have not previously been illustrated from the Dan– ish upper Oligocene, the fauna is extensively illustrated. Dinocyst assemblages have been studied to help date the investigated successions. The assemblages indicate that the glauconitic clay from Vilsund should be assigned to the provisionally named stratigraphical Unit X in Śliwińskaet al. (2012) or the lowermost Brejning Formation. Unit X was previously only known from the interval 61.5–67.5 m in the Harre-1 borehole. Schnetler & Beyer (1990) assigned the glauconitic clay in the coastal cliff at Mogenstrup to the Brejning Formation, but dinocyst studies herein indicate that these strata should be assigned either to Unit X, most likely the upper part, or the lowermost Brejning Formation (see Appendix). This interpretation is supported by the foraminifers and the pectinid species Palliolum hausmanni (Goldfuss, 1835). The occurrence of other nearby outcrops of differing Oligocene ages is demonstrated. The outcrops are described and dated by means of dinocysts and foraminifers and include a section showing a depositional contact between the lowermost Rupelian Viborg Formation and Chattian Branden Clay. The age of the Mogenstrup section is also demonstrated by means of dinocysts.

RADIOCARBON AND URANIUM PROFILES IN MARINE GASTROPODS AROUND THE JAPANESE ARCHIPELAGO

ABSTRACT In this study, we investigate the distribution of radiocarbon and uranium in the calcified opercula of Turbo sp. collected from Ryukyu region and Chiba, Japan, to explore the potential of U/Th dating using mollusks collected from the Japanese archipelago. We acquired high-resolution radiocarbon and uranium concentration measurements using single-stage accelerator mass spectrometry and laser ablation−inductively coupled plasma−mass spectrometry. Our results show that uranium in the opercula of modern Turbo sp. is unevenly distributed at concentrations 1000 times less than those in coral skeletons. Radiocarbon found in the calcified opercula samples record ambient seawater radiocarbon values as well as coral skeletons. Uranium in the calcified opercula of Holocene Turbo marmoratus were also unevenly distributed and concentrated within the opercula in a different manner than observed in modern samples, suggesting uranium exchange after death. Our results suggest variable uptake of uranium isotopes into mollusk shells and highlights the need for rigorous sample selection criteria when choosing mollusks species for U/Th dating around Japan.

Diversity of Freshwater Macroinvertebrate Communities in Los Tuxtlas, Veracruz, Mexico

The objective of this work is to contribute to the knowledge of the freshwater macroinvertebrate communities of Los Tuxtlas, Veracruz, Mexico. For this region, there is only limited knowledge of its aquatic crustaceans and mollusks. A total of 13,399 freshwater macroinvertebrates were collected from four river sections in each of the three sub-basins of the region using the Surber network in four seasons of an annual cycle (2021–2022) and were preserved in 70° alcohol. Organisms belonging to seven phyla, nine (sub)classes, 21 (sub)orders and 65 families were identified. The most abundant orders were Ephemeroptera (42.03%), with greatest abundance of the family Baetidae, and the orders Trichoptera (19.11%), Diptera (15.43%), and Coleoptera (3.98%). Four families exceeded 10% relative abundance, and together they total 61.02%: Baetidae (23.84%), Hydroptilidae (13.58%), Leptohyphidae (13.03%), Chironomidae (10.57%), and Elmidae (3.23%). The order Plecoptera was recorded for the first time in Los Tuxtlas, with three families. The orders Hydrachnidae and Ostracoda, as well as six families of the order Ephemeroptera, with only one previously recorded family, and six more families of the order Diptera, were also documented. Two species of invasive aquatic mollusks were found in several rivers and basins. In this work, a high diversity of freshwater macroinvertebrates occurred compared to other sites studied in Veracruz and Mexico, and new records of these taxa are provided for the region of Los Tuxtlas.

Radiological hazard assessment of 210Po in freshwater mussels (Sinanodonta jourdyi) and golden apple snail (Pomacea canaliculata) in Vietnam.

210Po is a significant source of ionizing radiation that people are exposed to through food globally. This paper presents the wide range of accumulation level of 210Po in the organs of two species of shellfish including freshwater mussel (Sinanodonta jourdyi) and golden apple snail (Pomacea canaliculata), common freshwater species in Vietnam. There was a significant correlation between 210Po activity in muscle to their mass and size of freshwater mussels. In contrast, there was no relation between other organs of both species with their mass and size. The annual effective dose due to consumption of freshwater mussels ranged from 68.7 to 291 μSv year-1 with a mean value of 138 μSv year-1 for muscle and from 321 to 4560 μSv year-1 with a mean value of 1422 μSv year-1 for the hepatopancreas. Meanwhile, the AED for golden apple snail was recorded to be higher with values ranging from 105 to 2189 μSv year-1 with mean value of 673 μSv year-1 for muscle and from 468 to 4155 μSv year-1 with a mean value of 2332 μSv year-1 for hepatopancreas. Thus, the consumption of these two types of shellfish is considered relatively safe, but the hepatopancreas gland must be removed before processing.

IDENTIFIKASI HEWAN INVERTEBRATA PADA FILUM MOLUSKA DI PESISIR PANTAI KENJERAN SURABAYA

One way to identify an object is to make observations to a place to find objects that will be examined, in this article we take invertebrate animal objects in the mollusca phylum on Kenjeran Beach Surabaya. Phylum mollusca are a group of soft-bodied and invertebrate animals with shell-protected bodies. Data collection was carried out using exploration and observation methods, with research data analysis techniques using descriptive analysis techniques. 5 species of mollusca were obtained on the Kenjeran Coast, namely sea snails (Bolinus brandaris), Hiatella arctica, Sorgenfreispira brachystoma, Eupleura caudata and Keoang mas (Pomacea canaliculate). The existence of this study aims to recognize invertebrate animals in the mollusk phylum and the important characteristics of the species we found there.

Monospecific mangrove reforestation changes relationship between benthic mollusc diversity and biomass: Implication for coastal wetland management

Anthropogenic causes are overtaking natural factors to reshape patterns of biodiversity and ecosystem functioning. Mangrove reforestation aimed at reversing losses of mangroves has been conducted worldwide for several decades. However, how reforestation influences the link between ecological processes that shape community diversity and the consequent effects on ecosystem functions such as biomass production is less well known. Here we used data collected before and after mangrove planting to examine the effects of reforestation on molluscan species richness and biomass production by testing the changes in species richness, compositional similarities, distance-decay effects (community similarity decreases with increasing geographical distance) in metacommunity across a regional scale of 480 km (23–27 °N) in southeast Chinese coasts. Additionally, we further detected the impact of landscape configuration caused by different intensities of reforestation on the mollusc community. After the mangrove reforestation, mollusc species richness and biomass increased significantly. The increases in species richness and biomass of mollusc community were mediated by reducing distance-decay effect, indicating an increase in relationship strength between species richness and biomass might be associated with a decrease in distance-decay effect with rising mangrove habitat. We highlight the importance of considering the effects of anthropogenic changes on the relationship between biodiversity and ecosystem functioning. Quantifying the distance-decay effect of these influences enables management decisions about coastal restoration to be based upon ecological mechanisms rather than wishful thinking or superficial appearance.

Contamination Status and Acute Dietary Exposure Assessment of Paralytic Shellfish Toxins in Shellfish in the Dalian Area of the Yellow-Bohai Sea, China

The Yellow-Bohai Sea is an important semi-enclosed continental shelf marginal seas with an intensive aquaculture industry in China. The current study analyzed the contamination status and the time variations of paralytic shellfish toxins (PSTs) in shellfish between 2019 and 2020 from the Yellow-Bohai Sea in the Dalian area and estimated the acute health risks to consumers in China. A total of 199 shellfish samples (including 34 Pacific oysters, 25 Mediterranean blue mussels, 34 Manila clams, 36 bay scallops, 34 veined rapa whelks and 36 bloody clams) were analyzed from four representative aquaculture zones around the Yellow-Bohai Sea in Dalian. Among the samples, scallops and blood clams were the shellfish species with the highest detection rate of PSTs (94.4%), and the highest level of PSTs was detected in scallops with 3953.5 μg STX.2HCl eq./kg (μg STX.2HCL equivalents per kg shellfish tissue), followed by blood clams with 993.4 μg STX.2HCl eq./kg. The contents of PSTs in shellfish showed a time variation trend, and autumn was the season of concern for PST contamination in Dalian. For general Chinese consumers, the probability of acute health risks to shellfish consumers from dietary exposure to PSTs was around 13%. For typical consumers in coastal areas of China, especially those with higher shellfish intake, there was an acute health risk associated with exposure to PSTs through shellfish consumption during the occurrence of harmful algal blooms. It is suggested that the government continue to strengthen the monitoring of the source of PSTs and the monitoring of harmful algal blooms and give reasonable advice on shellfish consumption for consumers in coastal areas, such as not eating scallop viscera.

The shellfishery in Chile: an analysis of 26 years of landings (1960-1985)

This work compiles Information on the development of the Chilean shellfish fishery. The landings and exportations valúes are analysed between 1960 and 1985. Correlations between work-force (number of artisanal shellfishermen), landing and económica! valúes of shellfish exportation are presented. A panoramic view of landings and their exportation for the main shellfish species is given. Moreover, an analysis of the present shellfish legal regulation in the country is compiled. Finally, we discuss the present State of the art regarding the basic knowledge on these resources accumulated in the country and identify gaps and the future lines of research that should be developed.

Carbon storage in mollusk shells: An overlooked yet significant carbon sink in terrestrial ecosystems

Mollusks, the second largest animal family, are found in a variety of ecosystems. As they grow, their shells absorb carbon and form calcium carbonate, making them an important storage place for carbon. However, the amount of carbon deposited in the carbonate shells of terrestrial mollusks throughout modern and geological history has not been quantified. In this study, we first conducted an investigation of carbon deposits in shells from various mollusk species at 470 modern surface soil sample sites across diverse terrestrial ecosystems in China. The deciduous broadleaf forest and shrublands exhibited a higher carbon deposition rate of ∼1.37 ± 2.15 and ∼1.56 ± 2.92 g C m−2/yr−1, while croplands and grasslands displayed a rate of ∼1.11 ± 1.95 and 1.07 ± 1.78 g C m−2/yr−1, respectively. Using geostatistical methods, we estimated the total shell carbon deposition of grassland, forest, shrublands, and croplands in China to be ∼3.39–5.45 × 106 t C yr−1, constituting ∼1.68–2.71 % of China's terrestrial carbon sink, an overlooked portion in previous studies. Additionally, we provided quantitative data on shell carbon fluxes spanning a remarkable 20,000-year period through over ten fossil sequences from loess deposits. The results underscore the continuous and abundant carbon deposition in mollusk shells across various locations for at least 20,000 years, highlighting the persistence and substantial accumulation of shell carbon deposits over time. Remarkably, we estimated that the total shell carbon deposition of loess sediments in China and the world over the past 20,000 years may reach 1.10 × 108 t C and 1.29 × 109 t C, roughly equivalent to an afforestation area of 2.32 × 106 km2 and 2.72 × 107 km2, respectively.

The Cent Fonts Aquifer: An Overlooked Subterranean Biodiversity Hotspot in a Stygobiont-Rich Region

The South of France is a biodiversity hotspot within Europe. Here, we present a comprehensive review of surveys conducted in the Cent Fonts aquifer, an overlooked subterranean biodiversity hotspot embedded in a region rich in stygobiotic species and threatened by climate change and water abstraction projects. Key studies, spanning from 1950 to 2006, show a progression in survey methods and results, although troglobiotic species remain poorly documented. With 43 stygobiotic species recorded, the Cent Fonts is the richest stygobiont hotspot in France. Most species are regional endemics, a quarter of which are considered vulnerable by the IUCN. The Cent Fonts also hosts several relict species and is the type locality of four species. Such a high biological value clearly deserves to be preserved. Our analysis warns of a possible decline in biodiversity, as eight of the species recorded in the 20th century were absent from the 2006 survey, suggesting potential threats of unknown origin. The capture of the Cent Font springs for water abstraction is discussed as a potential threat to this ecosystem and its unique biodiversity. Three new species of stygobiotic molluscs are described, one of which was collected in the Cent Fonts.

Fauna of sone groups of invertebrates of Erebuni State Reserve (Armenia

Aim. The aim of the work is to research the fauna of invertebrates in the Erebuni State Reserve. Material and Methods. As research material served invertebrates gathered in the Erebuni State Reserve. The work was carried out at the Scientific Centre for Zoology and Hydroecology, National Academy of Sciences, Republic of Armenia in the period 2019–2023. The material was from our own collections, as well as from collections of insects and mollusks of the Institute of Zoology. The identification and collection of insects and mollusks were done using standard methods. Results. An overview of some groups of invertebrates in the Erebuni State Reserve is here provided for the first time. As a result of the research, 35 species of Diptera, 15 species of Coleoptera, 44 species of Lepidoptera,10 species of aphids and 12 species of mollusks were identified. Some species are listed in the “Red Book” of Armenia and are under the protection of the state, and there are rare species and species found in the Republic of Armenia only in the reserve. 15 species of insects identified by us develop on 4 plant species included in the “Red Book” of Armenia. Conclusion. The Erebuni State Reserve is represented by a rather diverse and valuable fauna of invertebrates studied by us, including a number of rare and protected species. Species of invertebrates associated in their development with valuable wild, economically important and protected plants have been identified in the reserve. Identification of species diversity and trophic relationships of some groups of insects that develop on rare and protected plants of the reserve is relevant for natural areas under state protection, of which the Erebuni State Reserve is one.

Co-infection of two eukaryotic pathogens within clam populations in Arcachon Bay.

The parasitic species Perkinsus olseni (= atlanticus) (Perkinsea, Alveolata) infects a wide range of mollusc species and is responsible for mortality events and economic losses in the aquaculture industry and fisheries worldwide. Thus far, most studies conducted in this field have approached the problem from a "one parasite-one disease" perspective, notably with regards to commercially relevant clam species, while the impact of other Perkinsus species should also be considered as it could play a key role in the disease phenotype and dynamics. Co-infection of P. olseni and P. chesapeaki has already been sporadically described in Manila clam populations in Europe. Here, we describe for the first time the parasitic distribution of two Perkinsus species, P. olseni and P. chesapeaki, in individual clam organs and in five different locations across Arcachon Bay (France), using simultaneous in situ detection by quantitative PCR (qPCR) duplex methodology. We show that P. olseni single-infection largely dominated prevalence (46-84%) with high intensities of infection (7.2 to 8.5 log-nb of copies. g-1of wet tissue of Manila clam) depending on location, suggesting that infection is driven by the abiotic characteristics of stations and physiological states of the host. Conversely, single P. chesapeaki infections were observed in only two sampling stations, Ile aux Oiseaux and Gujan, with low prevalences 2 and 14%, respectively. Interestingly, the co-infection by both Perkinsus spp., ranging in prevalence from 12 to 34%, was distributed across four stations of Arcachon Bay, and was detected in one or two organs maximum. Within these co-infected organs, P. olseni largely dominated the global parasitic load. Hence, the co-infection dynamics between P. olseni and P. chesapeaki may rely on a facilitating role of P. olseni in developing a primary infection which in turn may help P. chesapeaki infect R. philippinarum as a reservoir for a preferred host. This ecological study demonstrates that the detection and quantification of both parasitic species, P. olseni and P. chesapeaki, is essential and timely in resolving cryptic infections and their consequences on individual hosts and clam populations.