Achatina Research Articles

Control of invasive alien species: The Giant African snail (Lissachatina fulica) a difficult urban public management challenge

In view of the population growth trends and urbanization processes, one of the current challenges is the surveillance and control of invasive alien species within urban settings, particularly of those species that can serve as vectors or reservoirs of diseases with the potential to affect human health. In this regard, the present study evaluated the public management for the surveillance and control of African snails (Lissachatina fulica) in the city of Santiago de Cali in Colombia between 2016 and 2019 and proposed minimum guidelines for their surveillance and effective control in the urban settings of developing countries. The Giant African snails can be intermediate hosts of various microorganisms that have a great impact on urban public health. The latter may include parasitic, viral, bacterial, and fungal diseases, which are transported by the snail to homes or nearby areas exposing humans and animals to contagion. In the Colombian case the most important are Angiostrongylus parasites, which can cause eosinophilic meningoencephalitis, gastrointestinal disorders in humans and pulmonary hemorrhage in dogs. However, it is also possible that the same snails carry other nematodes such as Aleurostrogylus which can affect cats and dogs in urban areas. Comprehensive actions are required to address the problems related to urban invasive species such the African snail in Santiago de Cali as well as to develop environmental public policies and implement through municipal and state public management. We concluded that government action should be supported by reliable data to identify cases in situ, and to determine pest, environmental, and ecoepidemiological variables. Qualitative and quantitative data analyses will contribute to effective decision-making and the development of control protocols designed for each specific urban scenario.

Fine-scale geographical sampling and molecular characterization of the giant African land snail in its invasive range in Asia shows low genetic diversity, new haplotypes and the emergence of another haplotype from the Indian Ocean Islands

Abstract Native to East Africa, the giant African snail Lissachatina [=Achatina] fulica (Bowdich, 1822) is a tropical crop pest and one of the world’s top 100 invasive species. It is now present in at least 52 countries worldwide, with an actively expanding range. Lissachatina fulica was first introduced to India in 1847, but subsequent arrivals in India and local patterns of spread remain unclear. This study uses the 16S rRNA gene to identify the extent of genetic variation in India by sampling Indian populations and comparing them with published sequence data. A total of 307 snails were collected from 178 localities in India and from a single locality in the UAE, and the 16S rRNA gene was amplified and sequenced. Eight haplotypes were identified from India of which four are newly recognized. The new haplotypes identified in this study have increased the number of L. fulica 16S rRNA haplotypes from 19 to 23. Examination of haplotype and nucleotide diversities revealed that genetic variation is low in India, the UAE and across Asia as a whole. The number of haplotypes was higher in India when compared to other invasive regions but all of the Asian haplotypes appear to be closely related to the most common haplotypes in the Indian Ocean Islands. Heavy trade between the snail-infested and native-range countries suggests that the variation observed in India might be traced back to its native range, but the lack of sampling and paucity of sequences from East Africa currently prevents a comparison. Tracing back the emergent haplotypes by additional sampling could throw more light on the spread of L. fulica.

Breeding of the Giant African Edible Snail (Achatina achatina Linnaeus, 1758) in Gbado-Lite city, Democratic Republic of the Congo

The objective of this study was to evaluate the effect of the nature of the food ration on the size, weight, weight gain and ex situ reproduction of the snail (Achatina achatina) in Gbado-Lite. The results of this work show that variations in size [from 8.2±1.2 cm at feeding (D0) to 9.9±2.1 cm at day D84 (snail farm A) and from 8.4±1.1 cm to 10.2±1.8 cm (snail farm B)]; hatching rate [88.2% (snail house A) and 94.2% (snail house B)]; weight [460±18.5 g at loading (D0) to 760±26.3 g on day D84 (snail house A) and 475±10.9 g to 760±26.3 g (snail house B)]; mean absolute weight gain 84 days after loading [37.7±12.0 g (snail house A) and 36.5±9.6 g (snail house B)] were not statistically different between snail houses including mean daily weight gain (0.450±0.1 g/d vs. 0.363±0.1 g/d) and survival rate (90% vs. 100%). Both formulations have the same effect on the reproduction of Achatina achatina in captivity. It is therefore desirable that more in-depth studies be conducted with the aim of popularizing this non-conventional breeding in the city of Gbado-Lite. Thus, in the current context of biodiversity erosion linked to human activities as well as environmental factors, snail farming can contribute to empowerment, improved socio-economic conditions and household resilience to climate change. 

English

African giant snail is a popular alternative source of animal protein in Ghana and many other countries. The meat is high in lean protein and mineral elements. Ready-to-use meat obtained from snails can compete with animal proteins found on the market. After shelling, snails produced some slime that interfered with preparation and processing of the meat. This study aimed to provide consumers with ready-to-use fresh snails conveniently available on the market. The best treatment for eliminating slime from snails was determined using a 2×10×3 factorial design. Vinegar plus salt treatment was the most effective slime removal treatment which led to a significant weight loss. Irradiation at all doses most effectively reduced the microbial load of snails after slime removal. A 6×4×3 factorial design was used for the shelf-life study. Irradiation at 1.5 and 3 kGy extended the shelf life of fresh snails by 14 extra days with the lowest microbial load. Radiation did not affect the fat and mineral content, but the protein content increased. Panelists preferred irradiated snails even though they had different odours and aromas. This study concluded that irradiating fresh snails even at lower doses can extend the shelf-life of fresh snails under refrigeration temperature.   Key words: Contamination, irradiation, Achatina achatina, A. marginata.

Extraction and Identification of Bioactive Compounds from Archachatina marginata (Giant African Land Snail).

Extraction and Identification of Bioactive Compounds from Archachatina marginata (Giant African Land Snail).

Public Health Risk of Foodborne Pathogens in Edible African Land Snails, Cameroon.

In tropical countries, land snails are an important food source; however, foodborne disease risks are poorly quantified. We detected Campylobacter spp., Yersinia spp., Listeria spp., Salmonella spp., or Shiga-toxigenic Escherichia coli in 57%–86% of snails in Cameroon. Snail meat is a likely vector for enteric diseases in sub-Saharan Africa countries.

Immunological indices of Giant African Land snails (Archachatina marginata) improved with fixed dose of vitamin C during acute heat stress

The study determined immunological indices of Giant African Land snail (Archachatina marginata) improved with fixed dose of vitamin C under acute heat stress (AHS). Prior to the AHS, vitamin C was administered for four weeks to two treatment groups, while other two treatment groups were not. Each treatment was monitored, haemolymph collected at 0, 30 and 60 minutes exposure times. Immunological cytokines: interferon gamma (IFN-γ) and interleukin 2 (IL-2); and total haemocyte counts (THC) were determined. Under AHS, vitamin C elevated (p <0.05) IFN-γ production (606.33 ± 302.86) compared to other groups with or without vitamin C administration (7.20 ± 1.58 vs. 73.20 ± 32.23 vs. 7.80 ± 1.36). IL-2 was not affected (p >0.05) by vitamin C under AHS. Highest (p <0.05) THC values was obtained with vitamin C administration under AHS, but reduced under no AHS. Exposure time affected (p <0.05) IFN-γ production and THC values, but not IL-2 (p >0.05). With fixed dose of vitamin C and exposure time, highest (p <0.05) IFN-γ values were obtained under AHS with vitamin C administration at 30 minutes and at 60 minutes in THC, compared to other groups. The study concluded that fixed dose of vitamin C at 150 mg kg-1 of feed was appropriate under AHS to boost the immune system of the animals.

Ecological invasion of the giant African snail Lissachatina fulica (Bowdich, 1822) in a semi-arid forest of western India.

The giant African snail Lissachatina fulica (Bowdich, 1822) (also known as Achatina fulica) is indigenous to the coastal region of con-tinental East Africa. It is one of the most invasive ecological pests in the world and threatens native flora, agriculture, human and animal health outside its natural range. While dry and semi-arid climatic re-gions are supposed to be immune to its invasion, our data show that this is not always the case. Ranthambhore National Park is dry, de-ciduous forest located in semi-arid part of western India. We have observed the progressive invasion of L. fulica in this fragile land-scape since its first introduction in 2010. Subsequently, it has spread over a large area at an alarming rate. We discuss the observations on behaviour and the factors responsible for the rapid spread of L. fulica in the park.

How Will the Distributions of Native and Invasive Species Be Affected by Climate Change? Insights from Giant South American Land Snails

Climate change and invasive species are critical factors affecting native land snail diversity. In South America, the introduced Giant African Snail (Lissachatina fulica) has spread significantly in recent decades into the habitat of the threatened native giant snails of the genus Megalobulimus. We applied species distribution modeling (SDM), using the maximum entropy method (Maxent) and environmental niche analysis, to understand the ecological relationships between these species in a climate change scenario. We compiled a dataset of occurrences of L. fulica and 10 Megalobulimus species in South America and predicted the distribution of the species in current and future scenarios (2040–2060). We found that L. fulica has a broader environmental niche and potential distribution than the South American Megalobulimus species. The distribution of six Megalobulimus species will have their suitable areas decreased, whereas the distribution of the invasive species L. fulica will not change significantly in the near future. A correlation between the spread of L. fulica and the decline of native Megalobulimus species in South America was found due to habitat alteration from climate change, but this relationship does not seem to be related to a robust competitive interaction between the invasive and native species.

First report of the presence of enterotoxin gene in coagulase-negative staphylococci recovered from meat of snails (Achatina achatina)

IntroductionIt has been suggested that coagulase-negative staphylococci can serve as reservoirs of virulence genes for other bacteria. This study assessed the presence of such genes in selected isolates recovered from meat of the giant African snail (Achatina achatina).Material and MethodsVirulence genes were detected using a polymerase chain reaction targeting specific primers. Two representative isolates were identified using 16S rRNA gene sequencing.ResultsThe results showed that the staphylococcal enterotoxin A gene (sea) was present in five out of the eight isolates studied. The isolates expressed resistance mainly to three antibiotics: chloramphenicol, norfloxacin and cloxacillin in descending order of incidence. Most importantly, the Staphylococcus sciuri isolate NEDU 181, in addition to being resistant to the three aforementioned antibiotics, also harboured the sea gene.ConclusionOur findings demonstrate, for the first time, the presence of toxigenic and antibiotic-resistant coagulase-negative Staphylococcus spp. in commercially-available fresh snail meat. With staphylococcal enterotoxin A known to survive cooking temperature, this presents a food safety concern.

Analysis of the Spatial Distribution of the African Crab in the City of Manaus / AM-Brazil

In 2003, the African snail was found for the first time in the city of Manaus, receiving from the Brazilian Institute of Environment and Renewable Resources the attribution of Achatina fulica, a species classified among the hundred worst invaders in the world. The present work presents the results of a study developed on the occurrence and the spatial distribution of this species in the capital of Amazonas. The methodological procedures were conducted through field collections, georeferencing and data projection on cartographic bases. As well as information on the conditions of precipitation, relative humidity and temperature, considering the influence of abiotic factors on the distribution of the species. The survey included 1,855 individuals, collected. The results reveal that temperature values ​​of 25 ° C accompanied by relative humidity rates of around 80% and average precipitation volumes of 17 mm bring together climatic conditions that favor the appearance of the mollusc in the city Manaus.

Socio-environmental assessment of the impact of the African snail, Lissachatina fulica (Férussac), 1821, on the population of Alto Paraíso de Goiás, Brazil

The introduction of the African snail Lissachatina fulica worldwide poses a risk to the environment, agriculture and human health. Considered a socio-environmental pest it causes problems to plantations and gardens, in addition to threatening native species. Also, it can be an intermediate host of worms that affect humans and mammals. This work aims to evaluate the socioenvironmental impact caused by L. fulica in Alto Paraíso de Goiás, Goiás, Brazil. Specifically, it aimed to analyze the residents' knowledge about L. fulica, if they were able to recognize the invasive snail and differentiate it from the giant native snail Megalobulimus sp., in addition to the community's ability to carry out actions to combat the invasive species. Semi-structured interviews were conducted, guided by a questionnaire, with the urban population, and an unstructured interview with a health surveillance agent in the municipality. The area of the city was divided into five zones and ten residences were visited in each zone. It was found that the residents most affected by L. fulica are those who live in the most urbanized region of the city, with 86% of respondents reporting seeing the animal in the city center. The presence of the Megalobulimus sp. was reported by four residents in the city's border regions with the native Cerrado. Most of the reports of the African snail in the houses occurred by residents of Alto Paraíso de Goiás who had plants in their backyard and personally took care of them.

Waste leachate induces histological alterations in Limicolaria aurora (Jay, 1839) digestive gland

Unsanitary open dumping and burning of wastes in dumpsites results to constant leaching of waste pollutants into the surrounding environment with attendant harmful consequences on wildlife and public health. Here, we investigated the histological effects of Onitsha municipal waste leachate on the Giant African land snail, Limicolaria aurora (Jay 1839). The histopathological effects of waste leachate on the digestive cells of the snails were examined following standard protocols. Snails were exposed to different concentrations (0, 6.25, 12.5, 25.0 and 50.0%) of the leachate for a total duration of 21 days. Histological results obtained showed that waste leachate caused dose and duration dependent alterations in the digestive glands of L. aurora. Obvious histological variations were observed in snails exposed to 50% concentrations of the leachate compared to other doses. Observed histological changes were mainly degeneration of the digestive tubules, fragmentation and disappearance of the digestive cells, marked increase in excretory cells, necrosis and epithelia sloughing. This study therefore highlights the potential toxicity of waste leachate of causing mild to severe damage in the tissues of organisms. Reinforcing the fact, that waste leachate contains a mix of toxic substances that could pose a severe injury to the biological system of surrounding biota, including humans.

The giant African snail Achatina (Lissachatina) fulica Bowdich, 1822 as an intermediate host of Aelurostrongylus abstrusus (Railliet, 1898) in the Rio de Janeiro state, Brazil.

Aelurostrongylus abstrusus is a metastrongilid nematode that causes feline aelurostrongylosis. The adult life stage parasitizes the lungs of wild and domestic felids. Terrestrial mollusks act as its intermediate host, and birds, amphibians, and small mammals act as paratenic hosts. Aelurostrongylus abstrusus presents a worldwide distribution, and in Brazil it has been recorded in most states. The present study investigates the occurrence of Aelurostrongylus abstrusus in terrestrial mollusks from urban areas of two out of the six Mesoregions of Rio de Janeiro state: Metropolitana and Centro Fluminense (46 municipalities). Larvae were recovered from the tissue of the mollusks collected during the surveys and identified based on morphology and sequences of the Internal Transcribed Spacer 2 (ITS2). In all, 2791 mollusks, belonging to 14 different species, were collected. Larvae of A. abstrusus were recovered from two species: Achatina fulica in 22 out of 46 municipalities, and from the slug Latipes erinaceus in 1 out of 46 municipalities. Aelurostrongylus abstrusus was recorded in half (50%) of the municipalities of the Metropolitana Mesoregion and in 44% of those of the Centro Fluminense Mesoregion. Results indicate a strong association between A. abstrusus and A. fulica, since 99% of the mollusks infected with A. abstrusus were A. fulica. This study recorded A. abstrusus in the Centro Fluminense Mesoregion and naturally parasitizing L. erinaceus for the first time. Despite the high number of mollusks infected with A. abstrusus and their wide distribution in Rio de Janeiro State, there are still few reports of infection in Brazilian felids, probably given that this is an under-diagnosed parasitosis in this country. Further studies in other regions of the Rio de Janeiro State, and other Brazilian States, focusing on intermediate and definitive hosts, particularly in the urban environments where they coexist, are needed. These studies will enable further understanding of the epidemiology and prevention of aelurostrongylosis.

Evaluation of Heterocyclic Aromatic Compound Dye (Methylene Blue) on Chitosan Adsorbent Sourced from African Snail Shell: Modelling and Optimization Studies

In this article, the modelling and optimization of five operational process parameters involving initial concentration, adsorbent dosage, contact time, temperature and pH of the solution as it affects the treatment of aqueous solution contaminated with methylene blue, a heterocyclic aromatic compound, on chitosan sourced from African Snail Shell were studied using response surface methodology (RSM) and artificial neural network (ANN) techniques coupled with genetic algorithm. The single and interactive effects of the variables were examined by way of analysis of variance (ANOVA). A comparison of the model techniques was done and an evaluation was carried out with some selected error functions. Both modelling and optimization tools performed creditably well. However, the hybrid ANN-GA proved to be a superior modelling and optimization technique with excellent generalization ability which gave an average absolute deviation between the experimental and predicted data of both response variables considered. The insightful relative importance of the process variables based on the renowned Garson and Olden’s algorithm methods coupled with step by step approach initiated in the Matlab environment were equally investigated. The findings from this study revealed in clear terms that pH and initial concentrations were the most influential parameters and the maximum value of 99.28% of methylene blue removed at optimum conditions affirmed that the chitosan adsorbent is viable for the treatment of effluents from the textile industry.

Polycyclic aromatic hydrocarbons in giant African snails Archachatina marginata (Swainson, 1821) (Gastropoda: Pulmonata Achatinidae) from southern Nigeria

Giant African snails were collected from different zones in southern Nigeria, and analyzed for their polycyclic aromatic hydrocarbon (PAH) content. The purpose was to provide information on the health risk arising from exposure to PAHs through consumption of these snails. A mixture of acetone/dichloromethane/n-hexane was used for the Soxhlet extraction of PAHs from the snail samples, and the resulting extracts were assayed by gas chromatography-mass spectrometry (GC-MS). The concentrations of the Ʃ17 PAH concentrations varied from 290 to 4180, 48–4150, 23–1560, 303–2970, and 2230–2880 µg kg−1 for snails purchased in Warri, Port Harcourt, Calabar, Onitsha, and Benin City zones respectively. The benzo(a)pyrene (BaP) concentrations in 53% of these snails exceeded the permissible limit of 6.0 µg BaP kg−1 in molluscs meant for consumption by humans. The PAH4 concentrations in 42% of these snail samples exceeded the specified limit of 35 µg kg−1 for molluscs. The hazard index (HI) from consumption of snails from these zones was less than one, while the total cancer risk relating to the consumption of snails from these zones by adults and children was of the order of 10−4 and 10−6, respectively. There is a need for caution in the consumption of snails from these regions because higher intake values than those assumed in this work could pose considerable carcinogenic risks to the consumers. The source analyses indicated PAHs in these snail samples originated from oil spills, biomass combustion, traffic emissions, and gas flaring.

Prediction of Antibacterial Peptides against Propionibacterium acnes from the Peptidomes of Achatina fulica Mucus Fractions.

Acne vulgaris is a common skin disease mainly caused by the Gram-positive pathogenic bacterium, Propionibacterium acnes. This bacterium stimulates the inflammation process in human sebaceous glands. The giant African snail (Achatina fulica) is an alien species that rapidly reproduces and seriously damages agricultural products in Thailand. There were several research reports on the medical and pharmaceutical benefits of these snail mucus peptides and proteins. This study aimed to in silico predict multifunctional bioactive peptides from A. fulica mucus peptidome using bioinformatic tools for the determination of antimicrobial (iAMPpred), anti-biofilm (dPABBs), cytotoxic (ToxinPred) and cell-membrane-penetrating (CPPpred) peptides. Three candidate peptides with the highest predictive score were selected and re-designed/modified to improve the required activities. Structural and physicochemical properties of six anti-P. acnes (APA) peptide candidates were performed using the PEP–FOLD3 program and the four previous tools. All candidates had a random coiled structure and were named APAP-1 ori, APAP-2 ori, APAP-3 ori, APAP-1 mod, APAP-2 mod, and APAP-3 mod. To validate the APA activity, these peptide candidates were synthesized and tested against six isolates of P. acnes. The modified APA peptides showed high APA activity on three isolates. Therefore, our biomimetic mucus peptides could be useful for preventing acne vulgaris and further examined on other activities important to medical and pharmaceutical applications.

Development in Pesticides for Control and Prevention of African Giant Snails, Achatina Fulica in Jalgaon, Dapoli Dist. Ratnagiri (M.S.)

In the present study the occurrence of the Giant African snail, Achatina fulica reported from Jalgaon, Dapoli District Ratnagiri (M.S), India in various field during rainy season but their occurrence is throughout the year. Due to hibernation, these are not much active as compared to rainy season. According to native people of the area, severe plant and vegetable loss was not only due to infestation but also due to the stinking smell of the mucus layer in wetland dry conditions released by the Giant African snail, Achatina fulica different plants. The pest, also classified as a large-scale invader, has been known to be difficult to exterminate without harming nearby organisms as well as ecosystems. Hence, there should be a proper method of control measure of this pest. The following article describes possible methods of control measures researched since ages chemical as well as non-chemical. Even though a lot were proven to be unsuccessful, some methods do play an important role in the extermination of this species with respect to collective efforts, destruction scale, costings etc.Mechanical extermination is a lot more effective than the chemicals introduced which have a possibility of getting washed away due to rains or other possible circumstances. This article mainly focuses on discussing previously studied control methods and defining the criteria needed to develop a suitable pesticide.

POST AESTIVATION DYNAMICS OF THE FEMALE REPRODUCTIVE ORGANS OF GIANT AFRICAN LAND SNAILS (ARCHACHATINA MARGINATA): HISTOLOGICAL AND HISTOCHEMICAL PERSPECTIVE

The study was carried out to monitor the recovering of the tissue of the female reproductive organs of Giant African Land Snail (Archachatinamarginata) (GALS) post aestivation. The histological and histochemical changes were examined at 0, 3 and 6 weeks of post aestivation. The experiment was conducted using forty (40) reproductively matured and apparently healthy snails, laid out in a completely randomized design, with 2 snails replicated four times. The histological and histochemicalsections were observed for tissue structural alteration, lipid, calcium and glycogen accumulation (or depletion) with H & E, Von Kossa and PAS staining techniques respectively. Prominent basement membrane with underlying supportive tissue was observed at the 6th week aestivation lengths. At the 3rd week of arousal, there were clearer lumen and mass of densely packed cells around the epithelium. The emergence of secretory epithelium cells were also observed at the 3rd week post dormancy. The control showed cells which were sparsely packed, oblique with a diminished structural conformation. At arousal, circular or pear shaped follicles were observed in the tissue of the albumin gland with conspicuous glandular cells and appearance of lumen. The follicles got progressively enlarged with rehydration (3P – 6P), closing up the intercellular spaces. The vagina showed a diminished lumen prominently lined with ciliated columnar epitheliumwith outstanding muscular walls which did not show substantial recovery within the investigated arousal periods. The Albumin gland tissues of Archachatinamarginata were positive for glycogen deposition. Intracellular storage form of carbohydrate (glycogen) was marginally evident in the 6th week aestivation section. On arousal, substantial improvement was not observed within the post aestivation period.

POST AESTIVATION DYNAMICS OF THE MALE AND HERMAPHRODITIC REPRODUCTIVE ORGANS OF GIANT AFRICAN LAND SNAILS (ARCHACHATINAMARGINATA): HISTOLOGICAL AND HISTOCHEMICAL PERSPECTIVE

The male reproductive organs and hermaphrodite ducts of the Giant African Land Snail (Archachatinamarginata) were examined histologically and histochemically at 0, 3 and 6 weeks post aestivation. The transverse section of the tissue of little hermaphrodite duct aestivated for 6 weeks (control) resulted in clear, wide and highly branched lumen lined with ciliated cuboidal epithelium. The post aestivation section at the 3rd week did not differ substantially. At the 6th week post aestivation, the muscular wall took a wavy and more branching appearance. The common hermaphrodite duct revealed a conspicuous intercellular spaces and sparse composition of the cellular components. The lumens were inflated with thick peripheral walls. The post aestivation sections tended toward recovery with much cellular prominence with discernible boundaries. The vas deferens generallyappeared organized with respect to segmentations and arrangement in the control. Adherence of cell mass and granules were typical features of the 6th week aestivated tissue. At arousal, these features diminished with farther dispersed cells and loosed connective tissues. Thepenis displayed multiplied and larger cell mass with clear lumen and increasing peripheral thickness. It can therefore be concluded that tissues of the male and hermaphroditic organs retained their firm conformation for six weeks dormancy period, Ca and lipid droplet regressed considerably. At arousal no substantial rejuvenation was attained 3rd week post aestivation but at the 6th week, adjustment toward reproductive preparation was observed with considerable calcium built up.