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The apple snail, Pomacea canaliculata (Lamarck, 1819), a freshwater snail listed as a pernicious invasive alien species by the World Conservation Union (IUCN), has caused serious agricultural and ecological harm worldwide. This species has inflicted significant agricultural and ecological damage on a global scale. Under conditions of extreme environmental stress, the apple snail enters a state of dormancy and remains in this dormant phase until environmental conditions become favorable again, which serves as a crucial survival strategy. In our study, we subjected apple snails to 30 days of air-exposure stress followed by rehydration to reactivate them. Our objective was to elucidate the underlying mechanisms associated with drought tolerance, dormancy, and subsequent arousal based on transcriptomic analyses. The results indicated that the groups subjected to 5-, 15- and 30-day air-exposure stress treatments (DRY05, DRY15 and DRY30) exhibited a general down-regulation of metabolism-related pathways. These pathways included starch and sucrose metabolism, linoleic acid metabolism, glutathione metabolism and glycosaminoglycan degradation, compared with the control (CK). In addition, the weighted correlation network analysis (WGCNA) identified two critical pathways: toll-like receptor signaling pathway and adherens junction. The down-regulation of these pathways indicated a decrease in immune levels during dormancy in apple snails. This may further lead to the inhibition of apoptosis and a reduction in energy expenditure, thereby sustaining vital activities. The up-regulation of intercellular adhesion and immune-related pathways upon reawakening (RCY01) further substantiates the presence of this tolerance mechanism during dormancy in the apple snail. This study provides a reference for understanding the tolerance of apple snails to extreme environments, and provides a basic theory for apple snail biocontrol research. [ABSTRACT FROM AUTHOR]

An increase in predation risk triggers a trait response of prey, which alters the interactions between the prey and other species, ultimately affecting other species in the ecosystem. Such predator‐driven trait‐mediated indirect effects (TMIEs) may have been shaped by long‐term evolutionary processes involving the organisms involved, but learning may also be important, especially in contemporary ecosystems experiencing repeated biological invasions. The apple snail Pomacea canaliculata is an important introduced pest of rice, Oryza sativa. Recently, the carrion crow Corvus corone has been found to prey on this species only in some areas, suggesting that learning is involved in this predation. In addition, apple snails can learn to escape from predators and exhibit predator‐specific responses. Thus, the "chain of learning" by the crow and the snail may shape novel TMIEs in the rice ecosystem. We conducted field and mesocosm experiments to test this hypothesis. In the field experiment, we simulated predation by crows in rice fields and investigated the behavior of apple snails. The snails exhibited escape behaviors in response to the simulated predation, and both the proportion of individuals showing the escape response and the degree of escape response were greater in fields with predation by crows than those without predation. In the mesocosm experiment, apple snails from fields with and without predation by crows were separately introduced into mesocosms simulating rice fields, and the behaviors of the snails and the number of remaining rice plants were recorded for 16 days at three levels of predation risk (daily, every 4 days, or no predation). Both the presence/absence of predation in the collection fields and simulated predation affected the escape responses of the snails. Moreover, damage to rice was more severe in mesocosms containing snails from fields without predation than those containing snails from fields with predation. These results suggest that the "chain of learning" causes TMIEs in agroecosystems. [ABSTRACT FROM AUTHOR]

Abstract An increase in predation risk triggers a trait response of prey, which alters the interactions between the prey and other species, ultimately affecting other species in the ecosystem. Such predator‐driven trait‐mediated indirect effects (TMIEs) may have been shaped by long‐term evolutionary processes involving the organisms involved, but learning may also be important, especially in contemporary ecosystems experiencing repeated biological invasions. The apple snail Pomacea canaliculata is an important introduced pest of rice, Oryza sativa. Recently, the carrion crow Corvus corone has been found to prey on this species only in some areas, suggesting that learning is involved in this predation. In addition, apple snails can learn to escape from predators and exhibit predator‐specific responses. Thus, the “chain of learning” by the crow and the snail may shape novel TMIEs in the rice ecosystem. We conducted field and mesocosm experiments to test this hypothesis. In the field experiment, we simulated predation by crows in rice fields and investigated the behavior of apple snails. The snails exhibited escape behaviors in response to the simulated predation, and both the proportion of individuals showing the escape response and the degree of escape response were greater in fields with predation by crows than those without predation. In the mesocosm experiment, apple snails from fields with and without predation by crows were separately introduced into mesocosms simulating rice fields, and the behaviors of the snails and the number of remaining rice plants were recorded for 16 days at three levels of predation risk (daily, every 4 days, or no predation). Both the presence/absence of predation in the collection fields and simulated predation affected the escape responses of the snails. Moreover, damage to rice was more severe in mesocosms containing snails from fields without predation than those containing snails from fields with predation. These results suggest that the “chain of learning” causes TMIEs in agroecosystems.

Several species of birds deliberately drop hard food items, such as walnuts and molluscs, from high places to break the shell and eat the content. Although the carrion crow Corvus corone preys on the introduced apple snail Pomacea canaliculata by directly breaking the shells with their beaks in paddy fields in Japan, snails living in ponds are too large and hard for crows to directly break the shells. We found that carrion crows dropped apple snails in and around dried ponds in winter in Marugame, Kagawa, Japan, and conducted detailed observations on their predation behaviour. The crows dropped the snails onto various substrates in and around Hachijo Pond, and the release point was higher when the substrate was wet mud than when it was concrete, rock, or grass. As carrion crows rarely prey on other freshwater snails in Japan, this foraging behaviour has likely developed since the introduction of apple snails in the 1980s. The intense predation by the crows likely reduced the snail density in this reservoir pond. [ABSTRACT FROM AUTHOR]

The destructive impact of invasive apple snail (Pomacea canaliculata) on young rice seedlings has garnered global attention, particularly in warm regions where rice production occurs. The preventative application of insecticide, particularly in areas with young rice seedlings and water depths exceeding 4 cm, has proven effective in mitigating this damage. In line with this recommendation, our study investigates the efficacy of site-specific drone-based insecticide applications to mitigate snail damage in rice paddies. These site-specific drone applications were strategically executed as directed by a highly accurate prescription map indicating the required insecticide quantity at specific locations. The prescription map was automatically generated through an advanced data processing program that used the aerial images acquired by a Real-Time Kinematic (RTK)-Unmanned Aerial Vehicle (UAV) as the input. Criteria were established to select the treatment locations; a value of below 4 cm from the top 95% percentile in the histogram of ground elevation data was used as a threshold to identify areas with a high-density of snail damage. The results demonstrated reductions in both the rates of rice damage and chemical usage following site-specific drone applications compared with the control fields. The findings in this study contribute to the advancement of effective site-specific pest control in precision agriculture. [ABSTRACT FROM AUTHOR]

Copyright of Revista de Ciências Agrárias is the property of Sociedade de Ciencias Agrarias de Portugal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this paper, the changes of superoxide dismutase (SOD) activity and malondialdehyde (MDA) content in hepatopancreas of Pomacea canaliculate in Guangzhou, Shanghai and Chengdu under different temperature, salinity and dissolved oxygen environmental stresses were studied to clarify the mechanism of environmental stress on the physiology of Pomacea canaliculate. The experimental results showed that under the stress of temperature, dissolved oxygen and salinity, the SOD activity and MDA content of the hepatopancreas of the snails increased first and then decreased, and reached the maximum value at 24 h~48 h, and returned to the initial level at 72 h. Under the combined temperature-salinity stress, the SOD activity and MDA content in the hepatopancreas of the snails were higher than those under the single factor stress, and the temperature and salinity showed a synergistic effect. Under single or complex stress, SOD activity and MDA content in liver and pancreas of the snails varied from region to region. [ABSTRACT FROM AUTHOR]

Background: In Kenya, rice (Oryza sativa L.) is mainly produced under irrigation by small‐scale farmers. Mwea irrigation scheme (MIS) in Kirinyaga County accounts for 80–88% of rice production. Here, rice is the main source of livelihood and a source of revenue generation for the county. However, a recently established invasive freshwater snail, Pomacea canaliculata (Lamarck) (family: Ampullariidae), a species of apple snail, presents a serious threat to rice production. Results: Household surveys, focus group discussions and key informant interviews highlight apple snail as a serious problem in MIS. Households that observed at least a moderate level of infestation (>20% of cultivated area) experienced significant reductions in rice yield (~14%) and net rice income (~60%). Farmers reported increased use of chemical pesticides for management of apple snail. In addition, the cost of hired labor for physical removal of egg masses and snails is resulting in substantial negative effects on net income. Farmer age, area of land owned, responsibility for decision‐making, receipt of extension advice, training, and membership of a farmer organization, were all statistically significant variables to explain farmers awareness of the need for area‐wide apple snail management. Conclusion: Strategies to limit the spread of apple snail are urgently needed. A Multi‐Institutional Technical Team (MITT) has been established to spearhead management efforts and consolidate advice to farmers on how to manage apple snail. However, without action to mitigate spread, the consequences could be disastrous for rice production and food security in Kenya, and for other rice growing regions across Africa. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The invasive golden apple snail Pomacea canaliculata has a strong reproductive capacity and has rapidly spread in Asian countries. Current control methods include physical, chemical, and biological approaches, but there has been limited research on the control of P. canaliculata in its different life stages. This study assessed the effectiveness of using giant river prawns Macrobrachium rosenbergii in controlling juveniles of P. canaliculata through a controlled indoor experiment. The density, size, and dispersal range of recently hatched juvenile snails were significantly lower among those kept with prawns than those kept without prawns, indicating a control effect of M. rosenbergii at least on P. canaliculata juveniles. Furthermore, the study speculates on the potential application of M. rosenbergii in the context of a rice–prawn symbiotic system of ecological farming to control invasive P. canaliculata. In terms of effectiveness and safety, its application might lead to a win-win situation for both rice-farm profits and the ecological benefits of invasive species control. [ABSTRACT FROM AUTHOR]

Simple Summary: In the adult freshwater snail, Pomacea canaliculata, their cephalic sensory tentacles can regenerate after experimental amputation. Immediately after the amputation, the wound closes and a hemocyte-rich blastema is formed, but whether hemocytes play a role in blastema formation and the regeneration process is not known. Here, we have analyzed the effects of the chemical depletion of phagocytic hemocytes on tentacle regeneration. The transient depletion of phagocytic hemocytes was achieved by injecting the snails with clodronate liposomes before tentacle amputation. Flow cytometry demonstrated the effects of clodronate liposomes on molluscan phagocytic hemocytes. Histological analysis, followed by an application of an in-house developed semi-automated hemocyte count protocol, documented that in phagocytic hemocyte-depleted snails, the regeneration process was significantly delayed. When the number of circulating phagocytic hemocytes was restored to the control values, the regeneration process recovered. The expression in the blastema of genes associated with hemocyte-mediated functions, like oxygen transport, clotting and inflammation, was evaluated using RT-qPCR. Consistent with flow cytometry and histochemical observations, the blastema from clodronate liposome-injected snails, presented significantly modified gene expression levels, thus reinforcing the hypothesis of an active role of hemocytes in the onset of tentacle regeneration. After amputation, granular hemocytes infiltrate the blastema of regenerating cephalic tentacles of the freshwater snail Pomacea canaliculata. Here, the circulating phagocytic hemocytes were chemically depleted by injecting the snails with clodronate liposomes, and the effects on the cephalic tentacle regeneration onset and on Pc-Hemocyanin, Pc-transglutaminase (Pc-TG) and Pc-Allograft Inflammatory Factor-1 (Pc-AIF-1) gene expressions were investigated. Flow cytometry analysis demonstrated that clodronate liposomes targeted large circulating hemocytes, resulting in a transient decrease in their number. Corresponding with the phagocyte depletion, tentacle regeneration onset was halted, and it resumed at the expected pace when clodronate liposome effects were no longer visible. In addition to the regeneration progress, the expressions of Pc-Hemocyanin, Pc-TG, and Pc-AIF-1, which are markers of hemocyte-mediated functions like oxygen transport and immunity, clotting, and inflammation, were modified. After the injection of clodronate liposomes, a specific computer-assisted image analysis protocol still evidenced the presence of granular hemocytes in the tentacle blastema. This is consistent with reports indicating the large and agranular hemocyte population as the most represented among the professional phagocytes of P. canaliculata and with the hypothesis that different hemocyte morphologies could exert diverse biological functions, as it has been observed in other invertebrates. [ABSTRACT FROM AUTHOR]

Copyright of Acta Zoologica Lilloana is the property of Fundacion Miguel Lillo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Invasive apple snails negatively impact non-native habitats and human well-being. Here, the trophic position of Pomacea canaliculata in native habitats (Maldonado, Uruguay) and non-native habitats (Hangzhou, China and Hawaii, USA) are compared. Detritus samples and tissue samples from apple snails were collected in all sites. Trophic levels were calculated as the difference between the mean δ15N values of detritus samples and corresponding apple snail tissue samples, divided by the mean δ15N fractionation for nitrogen per trophic level in freshwater habitats. The mean δ15N values of detritus in sites served as a baseline (i.e., zero trophic level), allowing direct comparisons. Linear regression analysis established a correlation between species evenness and apple snail trophic level (R2 = 0.8602) in line with a Pearson's product-moment correlation value (−0.83) and 95% confidence interval (−0.87, −0.77). Normal quartile plots indicated two normally distributed subsets of apple snail trophic-level data: (1) a biodiverse subset containing the Uruguayan and Chinese lake sites and (2) the homogenized Hawaiian and Chinese creek sites. A precipice value for species evenness (separating biodiversity from homogenization), between (3.7) and (2.4), once descended to or surpassed separates statistically distinct, normal distributions of invasive apple snail trophic-level data from diverse versus homogenized habitats. [ABSTRACT FROM AUTHOR]

Information on the oxidative stress physiology parameters (OSPP) in general and as a function of the fluctuation of Mg, Ca and organic carbon present in soil and aquatic physico-chemical factors such as pH, temperature and salinity in particular are scanty in the amphibious snail Pila globosa. A spatio-temporal analysis of redox metabolism (as OSPP) followed by discriminant function analysis of the obtained data were performed in P. globosa sampled from the east-coasts of Odisha state, India (mostly along the Bay of Bengal) for environmental health assessment purposes. Results revealed that the OSPP are susceptible to seasonal synergistic variation of soil and physico-chemical factors. Overall, lipid peroxidation, total antioxidant capacity, activities of catalase, glutathione reductase had positive correlation whereas ascorbic acid, the reduced glutathione and the activity of superoxide dismutase had non-significant correlation with the soil Mg, Ca, organic carbon, and pH, temperature and salinity of water. In the summer season, the snails had a marked 51.83% and 26.41% higher lipid peroxidation level and total antioxidative activity as compared to the other seasons. Spatial variation of OSPP indicates that snails residing away from the Bay of Bengal coast had at least 4.4% lower antioxidant level in winter and 30% higher lipid peroxide levels in summer as compared to the rest of the sampling sites. Results on OSPP in P. globosa may be useful for monitoring the ecotoxic effects of environment using molluscs in general and P. globosa in particular. [ABSTRACT FROM AUTHOR]

The freshwater gastropod Pomacea canaliculata fulfills the ideal conditions of a bioindicator species since its digestive gland bioconcentrates elements toxic for human and ecosystems health. The aim of this work was to study the balance between production of free radicals and antioxidant defenses, and the generation of oxidative damage in the digestive gland of this mollusk after exposure (96 h) to three elements with differential affinities for functional biological groups: mercury (5.5 μg/L of Hg+2 as HgCl2), arsenic [500 μg/L of (AsO4) −3 as Na3AsO47H²O], or uranium [700 μg/L of (UO2) +2 as UO2(CH2COOH)2]. Bioconcentration factors of Hg, As, and U were 25, 23, and 53, respectively. Snails exhibited a sustained increase of reactive species (RS), and protein and lipid damage. Lipid radicals increased between 72 and 96 h, respectively, in snails exposed to U and Hg while this parameter changed early (24 h) in As- exposed snails. Snails showed protein damage, reaching maximum values at different endpoints. This redox disbalance was partially compensated by non-enzymatic antioxidant defenses α-tocopherol (α-T), β-carotene (β-C), uric acid, metallothionein (MTs). Snails consumed α-T and β-C in an element-dependent manner. The digestive gland consumed rapidly uric acid and this molecule was not recovered at 96 h. Digestive gland showed a significant increase in MTs after elemental exposure at different endpoints. The enzymatic antioxidant defenses, represented by the catalase and glutathione-Stransferase activities, seems to be not necessary for the early stages of the oxidative process by metals. This work is the first attempt to elucidate cellular mechanisms involved in the tolerance of this gastropod to non-essential elements. The bioconcentration factors and changes in the oxidative status and damage confirm that this species can be used as a bioindicator species of metal pollution in freshwater bodies. [ABSTRACT FROM AUTHOR]

The destructive impact of invasive apple snail (Pomacea canaliculata) on young rice seedlings has garnered global attention, particularly in warm regions where rice production occurs. The preventative application of insecticide, particularly in areas with young rice seedlings and water depths exceeding 4 cm, has proven effective in mitigating this damage. In line with this recommendation, our study investigates the efficacy of site-specific drone-based insecticide applications to mitigate snail damage in rice paddies. These site-specific drone applications were strategically executed as directed by a highly accurate prescription map indicating the required insecticide quantity at specific locations. The prescription map was automatically generated through an advanced data processing program that used the aerial images acquired by a Real-Time Kinematic (RTK)-Unmanned Aerial Vehicle (UAV) as the input. Criteria were established to select the treatment locations; a value of below 4 cm from the top 95% percentile in the histogram of ground elevation data was used as a threshold to identify areas with a high-density of snail damage. The results demonstrated reductions in both the rates of rice damage and chemical usage following site-specific drone applications compared with the control fields. The findings in this study contribute to the advancement of effective site-specific pest control in precision agriculture.

Context: Alien freshwater snails pose a substantial risk to Australian native aquatic biota. Aims: This study aims to determine the thermal and salinity ranges of two introduced species within Australia, Pomacea sp. and Anentome sp., to facilitate predictions of their potential geographic range should they become widely established. Methods: Laboratory tests were conducted to assess behavioural responses of snails to altered temperature or salinity after different acclimation regimes. Key results: After acclimation at 25°C, Pomacea sp. had a median activity range of 13.5–38°C and Anentome sp. of 12–38.5°C. Higher acclimation temperatures produced observable effects, whereas lower acclimation temperatures did not. Salinity tolerances differed, with Pomacea sp. remaining active at up to 8 parts per thousand (ppt) (after acclimation at 25°C), with acclimation at 20°C resulting in a lower salinity tolerance. By contrast, Anentome sp. snails were active at up to 5 ppt after low salinity acclimation, demonstrating enhanced salinity tolerance compared with non-salinity acclimations. Conclusions: These results showed that both snails are capable of surviving temperatures and salinities that would allow invasion into subtropical and warm-temperate Australian aquatic systems. Implications: Free from the constraints of natural predators, competitors, and parasites, these snails should be of great concern to biosecurity agencies in Australia. Two exotic snail species, the 'apple snail' and the 'assassin snail', pose a particular threat to Australian freshwater ecosystems. In this study, we determined the ranges of temperature and salinity tolerances for these two species after acclimation to different conditions. Our results indicated that these species can tolerate temperatures and salinities that would allow them to survive in many Australian temperate and subtropical environments. [ABSTRACT FROM AUTHOR]

Invasive alien gastropods are a particularly pervasive taxonomic group worldwide, often causing substantial impacts on aquatic and terrestrial ecosystems. Yet, much remains unknown about this invasive group’s economic costs to human society. Here, we used the InvaCost database to evaluate the taxonomic, spatial, and temporal patterns of economic costs associated with invasive gastropods on the global scale. In total, 13 species of invasive gastropods caused a cumulative global cost of US$ 3.94 billion over the period 1966–2020, with a majority being attributed to aquatic species ($ 3.72 billion, 94.4 %, concentrated mostly in Asia) and only $ 0.22 billion (5.6 %, concentrated mostly in Europe) to terrestrial species. Among different regions, Asia (3.71 billion) reported the greatest costs, compared to far lower costs reported in Europe (214.50 million), North America (13.80 million), Oceania (2.69 million), South America (

Direct consequences of biological invasions on biodiversity and the environment have been largely documented. Yet collateral indirect effects mediated by changes in agri-environmental policies aimed at combating invasions remain little explored. Here we assessed the effects of recent changes in water management in rice farming, which are aimed at buffering the impact of the invasive apple snail (Pomacea maculata, Lamarck) on greenhouse gas emissions and diversity of waterbird communities. We used observational data from a 2-year field monitoring (2015–2016) performed at the Ebro Delta regional scale. We found that drying rice fields reduced methane emission rates by 82% (2015) and 51% (2016), thereby reducing the contribution of rice farming to climate change. However, there was a marked reduction (75% in 2015 and 57% in 2016) in waterbird diversity in dry fields compared with flooded fields, thus suggesting that post-invasion policies might hinder biodiversity conservation. Our results highlight the need for accounting for potential collateral effects during the policy decision-making process to design efficient agricultural management plans that lessen undesirable agri-environmental outcomes. [ABSTRACT FROM AUTHOR]

Studies on oxidative stress physiology on molluscs to monitor the aquatic environment, influenced by pollutants and stressors are very limited in general and in Indian apple snails, P. globosa in particular. The main focus of the present study was to establish the baseline data on a redox regulatory system in P. globosa sampled across the Indian subcontinent. Snails were sampled from different zones of India in three seasons (rainy, summer and winter) and the redox regulatory system (levels of antioxidant enzyme activities and small redox regulatory molecules) and oxidative stress indicator (lipid peroxidation) were analyzed. The observed elevated lipid peroxidation level in the summer season accompanied with elevated pH, salinity and temperature indicates induction of stress. In the summer season, the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione reductase (GR) enzymes were augmented, whereas the level of the free -SH group and the activities of glutathione peroxidase (GPx) and glutathione-S-transferase (GST) were found to be increased. Similarly, correlation analysis between the antioxidant system and aquatic parameters revealed that SOD, CAT and GR were influenced by pH as well as salinity, whereas CAT was strongly correlated with temperature. Collectively, our data indicate the use of P. globosa as a model organism to monitor and access the freshwater environment by determining the redox regulatory status of this animal. [ABSTRACT FROM AUTHOR]

BACKGROUND: The ability to efficiently visualize and manipulate chromosomes is fundamental to understanding the genome architecture of organisms. Conventional chromosome preparation protocols developed for mammalian cells and those relying on species-specific conditions are not suitable for many invertebrates. Hence, a simple and inexpensive chromosome preparation protocol, adaptable to multiple invertebrate species, is needed. RESULTS: We optimized a chromosome preparation protocol and applied it to several planarian species (phylum Platyhelminthes), the freshwater apple snail Pomacea canaliculata (phylum Mollusca), and the starlet sea anemone Nematostella vectensis (phylum Cnidaria). We demonstrated that both mitotically active adult tissues and embryos can be used as sources of metaphase chromosomes, expanding the potential use of this technique to invertebrates lacking cell lines and/or with limited access to the complete life cycle. Simple hypotonic treatment with deionized water was sufficient for karyotyping; growing cells in culture was not necessary. The obtained karyotypes allowed the identification of differences in ploidy and chromosome architecture among otherwise morphologically indistinguishable organisms, as in the case of a mixed population of planarians collected in the wild. Furthermore, we showed that in all tested organisms representing three different phyla this protocol could be effectively coupled with downstream applications, such as chromosome fluorescent in situ hybridization. CONCLUSIONS: Our simple and inexpensive chromosome preparation protocol can be readily adapted to new invertebrate research organisms to accelerate the discovery of novel genomic patterns across the branches of the tree of life.

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Abstract Background Although the apple snail Pila globosa is used as indicator species for human consumption locally and as fish feed, research on it in general is very scanty. It is used in food industry, in aquaculture as fish bait and used as food in many regions of India and many other countries, but research on it has been started in the 1970s. Only 40 articles are available on this organism in PubMed indicating an urgent need of basic research on it especially work on its spatiotemporal morphometry Therefore, sampling of P. globosa was done from different parts of India in different seasons (summer, winter and rainy), and different morphometric studies were performed on this organism to draw baseline information. Analysis was conducted to study morphometry, the relationship between shell length and the weight and relative condition factor of Indian apple snail Pila globosa collected from five zones (east, west, north, south and centre) of India during 2018–2019 year. Results The shell length (SL) (46.5 ± 13.33), shell width (SW) (40.22±11.5 mm), spire length (SPL) (2.99±0.15 mm), base length (BL) (12.53±2.94 mm), aperture length (AL) (21.95±4.36 mm), aperture width (AW) (2.74±0.47 mm) and shell weight (WT) (31.08±13.76 g) were observed to be varied among the individual sampled across India. Different relationships for SL/SW (Log SW=0.9889 Log SL + 0.9444), SL/SPL (Log SPL = 0.1452 Log SL+0.3815), SL/BL (Log BL=0.7789 Log SL+0.5814), SL/AL (Log AL= 0.6518 Log SL+0.9111) and SL/AW (Log AW=0.4475 Log SL+0.1422) were observed by considering shell length as basic index. The relationship between shell length and shell weight was found to be Log WT=2.0263 Log SL+0.1098. The relative condition factor revealed uninterrupted and good environmental condition observed for apple snails. A negative allometric growth pattern was observed from the length–weight relationship. Conclusion The environments of apple snail in India are not contaminated, and the results can be used as baseline data in aquaculture for model analysis and can be used as a reference for drawing relationship among different morphometric indices of P. globosa in India, as there is no such information available on it. The data can also be used for mass scale production of P. globosa for consumption by human and use in aquatic industries as fish feed.

Abstract Following reports of an invasive snail causing crop damage in the expansive Mwea irrigation scheme in Kenya, samples of snails and associated egg masses were collected and sent to CABI laboratories in the UK for molecular identification. DNA barcoding analyses using the cytochrome oxidase subunit I gene gave preliminary identification of the snails as Pomacea canaliculata, widely considered to have the potential to be one of the most invasive invertebrates of waterways and irrigation systems worldwide and which is already causing issues throughout much of south-east Asia. To the best of our knowledge, this is the first documented record of P. canaliculata in Kenya, and the first confirmed record of an established population in continental Africa. This timely identification shows the benefit of molecular identification and the need for robust species identifications: even a curated sequence database such as that provided by the Barcoding of Life Data system may require additional checks on the veracity of the underlying identifications. We found that the egg mass tested gave an identical barcode sequence to the adult snails, allowing identifications to be made more rapidly. Part of the nuclear elongation factor 1 alpha gene was sequenced to confirm that the snail was P. canaliculata and not a P. canaliculata/P. maculata interspecies hybrid. Given the impact of this species in Asia, there is need for an assessment of the risk to Africa, and the implementation of an appropriate response in Kenya and elsewhere to manage this new threat to agriculture and the environment.

Unregulated use of chlorpyrifos (CPF) and monocrotophos (MCP) in agriculture casts adverse effects on non-target freshwater mollusc, Pila globosa and humans. Levels of CPF and MCP were assessed in the paddy field from the edible foot tissue of apple snail (Pila globosa) exposed to low (1.5 ml l−1 water) and high (2.5 ml l−1 water) agricultural doses for 48 h to determine human health risk associated with consumption of tissue. CPF and MCP were extracted by liquid–liquid extraction and analysed by QuEChERS method using GC–MS/MS. For low and high concentrations of CPF exposure, the pesticide residue levels in the paddy field water ranged from 4.43 to 1.08 and 5.13 to 1.53 µg l−1, respectively, whereas, for low and high concentrations of MCP exposure, the residue levels in water ranged from 16.43 to 5.78 and 31.41 to 9. 27 µg l−1, respectively, for 3–48 h. In the foot tissue, residues ranged from 4.36 to 15.54 µg kg−1 for low-dose CPF, 7.1 to 18.05 µg kg−1for high-dose CPF and from 5.28 to 12.3 µg kg−1 and 8.94 to 18.21 µg kg−1 for low and high dose of MCP, respectively, during 3 to 48 h of exposure. Pesticides in the tissue were lower than the recommended maximum residue limits. Estimated health risk for adults and children revealed that the estimated daily intake values did not exceed the threshold values of acceptable daily intake. Non-carcinogenic and carcinogenic health effects were less than the safe value of 1.0 and 1 × 10−6, respectively, suggesting that CPF and MCP residues from ingestion of apple snail posed low risks to both children and adults. This preliminary result suggests regular monitoring of pesticides residues in Pila globosa collected from the paddy field of India. [ABSTRACT FROM AUTHOR]

Apple snail is a source of animal protein that has a high enough protein. Protein can be hydrolyzed by natural proteases, which one is bromelain. Enzymatic hydrolysis can produce hydrolysates containing peptides and amino acids that contribute to umami taste. The purpose of this study was to determine the effect of hydrolysis time and bromelain concentration on the physicochemical properties of apple snail hydrolysate. The optimal result in this study were used as natural flavor enhancer. This study used a completely randomized design with two factors. Factor I was the hydrolysis time (6 hours, 12 hours, and 18 hours) and factor II was the concentration of the bromelain (5%, 10%, and 15%). Based on the results showed that apple snail hydrolysate was influenced by hydrolysis time and bromelain concentration. The optimal result in this study was 18 hour hydrolysis treatment with 15% bromelain enzyme concentration had a yield 68.16%, degree of hydrolysis 72.09%, soluble protein 9.03%, total peptide 10.84 mg/mL, and glutamic acid 107.47 ppm. The application of apple snail protein hydrolysate give characteristics of flavor enhancers as follows: soluble protein 7.76%, glutamic acid 99.42 ppm, solubility 94.79%, water absorption 5.80 mL/g, hedonic test color 4.10 (neutral), aroma 5.05 (like slightly), and taste 5.10 (like slightly). [ABSTRACT FROM AUTHOR]

The present work investigated the meat yield of the gastropod Pomacea dolioides (Reeve, 1856), and sensorially evaluated its main organoleptic properties. The average meat yield of P. dolioides was 11.9 ± 3.4%, of which 10.9 ± 3.3% was for young females, 12.5 ± 2.8% for adult females, 12.1 ± 4.2% for young males, and 12.4 ± 2.2% for adult males. No significant difference was found in meat yield between sex, but a significant difference was detected in size. A significant difference was also found in the sensory analysis, as the treatment in which the gastropods were fed with grass and ration obtained the best evaluation, reaching over 70% approval for all meat attributes. Although the meat yield of P. dolioides was low, its general quality was satisfactorily accepted by the panellists. The meat of this commercially unexploited gastropod is a source of low-cost protein for people with dietary food limitations and underprivileged populations of the Amazon region, and might constitute an alternative and supplementary source of income for local animal producers. [ABSTRACT FROM AUTHOR]

The impact of two organophosphorus insecticides [Chlorpyrifos (CPF) and Monocrotophos (MCP)] on non-target wild natural gastropod, Pila globosa (apple snail) from the paddy fields was studied. The activity of acetylcholinesterase (AChE) was monitored on foot-muscle and hepatopancreas tissues of control and exposed snails. In the foot- muscle AChE inhibition progressed and reached 54.19% and 63.13% of the control, whereas, the AChE inhibition in the hepatopancreas reached 46.96% and 53.67% over control after 48 hours of exposure to 1.5 mL.L-1 and 2.5 mL.L-1 CPF respectively. After 48 hours of MCP exposure at 1.5 mL.L-1 and 2.5 mL.L-1 separately, the AChE inhibition of foot muscle was 49.07% and 57.59% respectively while in hepatopancreas it was 44.65% and 48.84% respectively. Our results show more inhibition of AChE activities on the foot-muscle than hepatopancreas in a concentration and time-dependent manner with greater severity by CPF in comparison to MCP. AChE inhibition increased with the increasing exposure time. [ABSTRACT FROM AUTHOR]

Background: Although the apple snail Pila globosa is used as indicator species for human consumption locally and as fish feed, research on it in general is very scanty. It is used in food industry, in aquaculture as fish bait and used as food in many regions of India and many other countries, but research on it has been started in the 1970s. Only 40 articles are available on this organism in PubMed indicating an urgent need of basic research on it especially work on its spatiotemporal morphometry Therefore, sampling of P. globosa was done from different parts of India in different seasons (summer, winter and rainy), and different morphometric studies were performed on this organism to draw baseline information. Analysis was conducted to study morphometry, the relationship between shell length and the weight and relative condition factor of Indian apple snail Pila globosa collected from five zones (east, west, north, south and centre) of India during 2018–2019 year. Results: The shell length (SL) (46.5 ± 13.33), shell width (SW) (40.22±11.5 mm), spire length (SPL) (2.99±0.15 mm), base length (BL) (12.53±2.94 mm), aperture length (AL) (21.95±4.36 mm), aperture width (AW) (2.74±0.47 mm) and shell weight (WT) (31.08±13.76 g) were observed to be varied among the individual sampled across India. Different relationships for SL/SW (Log SW=0.9889 Log SL + 0.9444), SL/SPL (Log SPL = 0.1452 Log SL+0.3815), SL/BL (Log BL=0.7789 Log SL+0.5814), SL/AL (Log AL= 0.6518 Log SL+0.9111) and SL/AW (Log AW=0.4475 Log SL+0.1422) were observed by considering shell length as basic index. The relationship between shell length and shell weight was found to be Log WT=2.0263 Log SL+0.1098. The relative condition factor revealed uninterrupted and good environmental condition observed for apple snails. A negative allometric growth pattern was observed from the length–weight relationship. Conclusion: The environments of apple snail in India are not contaminated, and the results can be used as baseline data in aquaculture for model analysis and can be used as a reference for drawing relationship among different morphometric indices of P. globosa in India, as there is no such information available on it. The data can also be used for mass scale production of P. globosa for consumption by human and use in aquatic industries as fish feed. [ABSTRACT FROM AUTHOR]

Invasive species threaten biodiversity, ecosystem functions, and human health around the world. Accurate and reliable species delineation and identification are prerequisites for any effort to control the introduction of new species and the spread of those already introduced. The advent of DNA assisted taxonomic tools has fueled the development of diverse and innovative approaches often touted as simple, inexpensive, and universally applicable for addressing impediments to rapid identification of non-native species. Ampullariidae (apple snails) are a family of freshwater snails with at least five species that have been introduced outside their native range and a prime example of how taxonomic uncertainty may hamper our understanding of invasion biology. Matsukura et al. (Appl Entomol Zool 43(4):535–540, 2008) and Cooke et al. (Conserv Genet Resour 4(3):591–593, 2012) developed species-specific PCR primers as rapid, simple, and inexpensive approaches to distinguishing among and identifying the most notorious and widespread invasive apple snails, Pomacea canaliculata and Pomacea maculata, and a third species in the aquarium trade, Pomacea diffusa. Neither approach was evaluated within the context of the overall genetic diversity of the target species, or with consideration for the species diversity within the family. To evaluate both shortcut approaches, the primers were tested for their utility in delineating and identifying the target species and other closely related taxa, including 24 apple snails representing 21 species. The results indicate that the primers are of limited taxonomic utility, and fail to consistently identify the target taxa, or congenerics. More importantly, use of these primers without additional data leads to misidentifications, potentially endangering native biodiversity and allowing novel introduced species to go undetected. [ABSTRACT FROM AUTHOR]

Apple snails Pomacea canaliculata and Pomacea maculata are herbivorous freshwater gastropods native to South America and are introduced species widespread in western and southern Japan. Although they affect rice culture and are invasive to native ecosystems, high‐resolution distribution data are not available for these species. I mapped the distribution of Pomacea species using the citizen science approach, by asking volunteers to report the geographical location along with the presence or absence of apple snail egg capsules or snail shells during 2017–2019. In total, 1,304 present and 508 absent records were collected, which revealed the distribution outlines of apple snails, especially in the Kansai area. Here, I provide a dataset of observation dates, location coordinates, volunteer names, and supplemental information. The complete data set for this abstract published in the Data Paper section of the journal is available in electronic format in MetaCat in JaLTER at http://db.cger.nies.go.jp/JaLTER/metacat/metacat/ERDP-2020-19.1/jalter-en. [ABSTRACT FROM AUTHOR]

The Snail Kite (Rostrhamus sociabilis plumbeus) is a wetland-dependent raptor that feeds primarily on aquatic apple snails (Pomacea sp.). In the United States, Snail Kites are endangered and breed exclusively in south and central Florida. Here we report that in 2018 and 2019, Snail Kites bred approximately 175 km north-northwest of the current northernmost breeding range. We combine historical and present information to interpret this new breeding event. Breeding occurred at Payne’s Prairie Preserve State Park, an isolated wetland in Alachua County, Florida, USA, that was impacted in 2017 by high water levels due to Hurricane Irma and invasion of exotic apple snails (P. maculata). Counts of Snail Kites within the area rose steadily throughout 2018 and 2019 from 1 to a high of 84 individuals. We discovered 3 nests with eggs or chicks in 2018, and 75 nests in 2019, with nest success rates of 100% and 40%, respectively. To our knowledge, sightings within the county from 1968 to 2017 occurred on only 7 occasions, and nesting was observed only once, in 1919. From 2005 to 2019, the extent of Snail Kite breeding in counties across Florida was greater than previous years. However, long-term range expansion may depend on maintenance of wetland conditions as well as a number of factors including snail availability, drought, hydrology, predation, and temperature. [ABSTRACT FROM AUTHOR]

Global change is the origin of increased occurrence of disturbance events in natural communities, with biological invasions constituting a major threat to ecosystem integrity and functioning. The apple snail (Pomacea maculata) is a freshwater gastropod mollusk from South America. Considered one of the 100 most harmful invasive species in the world, due to its voracity, resistance, and high reproductive rate, it has become a global problem for wetland crops. In Catalonia, it has affected the rice fields of the Ebre Delta since 2010 with significant negative impact on the local economy. As a gastropod mollusc it possesses statocysts consisting of a pair of sacs, one located on each side of the foot, that contain multiple calcium carbonate statoconia. This study shows the first ultrastructural images of pathological changes in the sensory epithelium of the statocyst of apple snail adults with an increase in the severity of the lesions over time after exposure to low frequency sounds. Sound-induced damage to the statocyst could likely result in an inhibition of its vital functions resulting in a potential reduction in the survival ability of the apple snail and lead to an effective mitigation method for reducing damage to rice fields.

Aquatic habitats have been highly modified by human actions that reduce their native diversity and create conditions suitable for tolerant alien species. Pomacea maculata was detected in 2009 in both the alluvial plain and the final stretch of the Ebro River. Since then, a permanent population has stabilized in the littoral area of the river where the water level fluctuates according to the river discharge. Melanopsis tricarinata is an endemic snail species highly affected by the reduction in its natural habitat. Currently, the two species do not share the same reaches in the river, but the possibility exists, as the distribution of the P. maculata is constantly increasing. This study aims to analyse the diets and to assess the responses of both snails to global change. The diet of both species was analysed in the field and their responses to water warming and dryness compared under laboratory conditions. This study includes the calculation of future river water temperatures based on air temperature projections. In addition, based on water discharge management scenarios, the study estimated the increase in dry river bed area. The diet of both snail species was similar and based on Cladophora. P. maculata better resisted high temperatures and dry conditions than M. tricarinata. The projections of water temperatures showed an increase in daily temperatures, especially in summer. The hydraulic model suggested that a relevant increase in dry river bed areas will occur. Overall, these results provide insight into the global change factors that could favour P. maculata spread in the river and the reduction in suitable habitat for M. tricarinata and will be useful for future decisions of water discharge management. [ABSTRACT FROM AUTHOR]

Abstract The rudimentary recycling of electronic waste (e-waste) has been banned in China since the late 2000s, leaving many abandoned e-waste sites. However, knowledge is limited on the concentrations and fates of the e-waste derived contaminants such as polychlorinated biphenyls (PCBs) in these abandoned sites. In this work, we assessed the temporal trend of PCB concentrations in the year 2010, 2012, and 2016 at an abandoned e-waste site in South China, using apple snail as a bioindicator. The mean ∑PCBs concentrations in apple snails sampled in 2016 (53.2 ng/g dry weight) was approximately 11-fold higher than that (4.68 ng/g dry weight) in apple snails from a reference site. The result suggested that the abandoned e-waste recycling site was still heavily polluted by PCBs, despite of the fact that crude e-waste recycling processes have been prohibited for nearly 10 years. The concentrations of ∑PCBs were significantly decreased in 2016 compared to those in 2010 (mean: 115 ng/g dry weight) and 2012 (mean: 92.3 ng/g dry weight), but there were no significant differences in the concentrations between 2010 and 2012. Regarding the congener profiles, the contributions of lower chlorinated congeners (tri- and tetra-PCBs) in the snails tended to be higher over the years. The ∑PCBs in snails were significantly correlated with those in soils. Additionally, PCB profiles in snails resembled those in soils. These results suggested that apple snails can be used as an ideal bioindicator for PCBs in the paddy soils. Field determined biota-soil accumulation factors (BSAFs) for PCBs ranged from 0.31 to 1.9, with most of the values being 1–2; indicating that theoretical BSAFs can be used to predict the bioaccumulation of PCBs in the snails with a reasonable degree of certainty. Graphical abstract Unlabelled Image Highlights • PCBs in apple snails from the abandoned e-waste site decreased during 2010–2016. • The contribution of lighter PCB congeners increased over the years. • Theoretical BSAFs could predict the bioaccumulation of PCBs in apple snails. • Apple snail is a suitable bioindicator for PCBs in paddy field soils. [ABSTRACT FROM AUTHOR]

The Limpkin (Aramus guarauna) is a medium-sized wading bird found in peninsular Florida and Central and South America, whose distribution is strongly tied to the presence of apple snails (genus Pomacea). Historically, Limpkins have been infrequently observed in the lower Apalachicola-Chattahoochee-Flint (ACF) watershed, including Lake Seminole, the most downstream reservoir in the system. In the past decade in Lake Seminole, a rapid increase in the nonnative P. maculata has been documented. In 2016, a Limpkin was observed in the lake, and we made efforts to document all subsequent Limpkin observations there. In the following year, we observed Limpkins (including several mating pairs) each month from February to July 2017. Limpkins were only observed in the Flint River section of the reservoir, the same area where the greatest abundance of P. maculata has been documented. We hypothesize the rapid increase of P. maculata is responsible for the recent regular Limpkin observations at the lake because observations of Limpkins prior to the recent expansion of P. maculata were rare and infrequent. Apple snails are likely to expand within the southeastern United States in the future, thereby creating additional suitable habitat for Limpkins and other specialist avian predators of apple snails. [ABSTRACT FROM AUTHOR]

The African apple snail, Pila ovata, is a common local delicacy in the southern regions of Nigeria but little information is available on their parasite fauna. In this investigation, P. ovata collected from a freshwater pond in Obazuwa in Edo State, Nigeria, were screened for parasites. Xiphidio cercariae and sporocysts collected from infected snails were molecularly characterized using partial large sub-units of ribosomal DNA. Phylogenetic reconstruction based on the sequenced data indicated that the parasite belonged to an un-described genus/family within the super family Microphalloidea of digenetic trematodes. Future lifecycle elucidation studies will attempt to describe adult stages of the parasite, identify its definitive host and investigate its possible zoonotic importance. [ABSTRACT FROM AUTHOR]

This study investigated the feasibility of using an invasive snail, Pomacea canaliculata, as a food source and water purifier for the commercial breeding of the loach Misgurnus anguillicaudatus. The predatory potential of M. anguillicaudatus (3.5-5.5 g) against hatchling snails was evaluated in aquaria and simulated paddy fields. Some hatchling snails left the water to avoid being preyed upon by the loaches, and approximately 10 hatchlings died per day in the presence of five loaches in aquaria, whereas a weaker snail control effect was observed in the simulated paddy fields. The growth of rice seedlings (Oryza sativa) was not reduced by the presence of hatchling snails alone, but the shoot biomass of seedlings coexisting with snails was promoted after introducing the loaches. Additionally, the presence of P. canaliculata adults improved the aquatic environment in the short term for loach breeding by decreasing the turbidity of the water. Importantly, M. anguillicaudatus (12-18 g) mortality decreased and its weight increased in the presence of adult snails. [ABSTRACT FROM AUTHOR]

The albumen gland of Pomacea canaliculata secretes the perivitelline fluid (PVF) surrounding the developing embryo which gives its eggs a highly effective defence against environmental factors and predators. Although previous studies have determined the functions of some PVF proteins extracted from P. canaliculata eggs, knowledge of the protein composition of PVF is still limited. In this study we use LC-MS/MS to identify 87 proteins from the albumen gland of P. canaliculata, 53 of which (60.9%) were annotated using the KEGG database. These classified into five functional groups: metabolism (54.7%); genetic information processing (9.4%); environmental information processing (3.8%); cellular processes (11.3%); and organismal systems (20.8%). The analyses found 12 proteins related to innate immunity and three proteins linked to defence against predation, providing important information for studies on embryo survival strategies and the invasive capabilities of P. canaliculata. [ABSTRACT FROM AUTHOR]