African Land Snail Achatina Fulica Research Articles

Nematodes of concern to public and animal health associated with the invasive snail Achatina fulica, in Sergipe, Northeastern Brazil

The giant African land snail Achatina fulica is known to be the intermediate host of a number of nematode species that are prejudicial to human and veterinary health, being also an agricultural and urban pest. The present study investigated the presence of nematodes in A. fulica and other terrestrial mollusks in 24 municipalities of Sergipe State, northeastern of Brazil, in the dry and rainy seasons. In 2019 and 2020, the specimens were collected in standard 20 m × 10 m plots (10 min/01 collector), while in 2021, they were collected by convenience sampling. The nematode species were identified based on sequencing of the mitochondrial Cytochrome C Oxidase Subunit I (COI) gene and the ribosomal nuclear Internal Transcribed Spacer (ITS 2). Specimens of A. fulica infected with Angiostrongylus cantonensis, a nematode that causes eosinophilic meningitis (EM) in humans and animals, were collected in four municipalities. Two nematodes of veterinary importance were also identified, Aelurostrongylus abstrusus and Cruzia tentaculata in seven municipalities. This is the first record of Cruzia tentaculata in Sergipe. Free-living nematodes were also found in 18 municipalities. One of these species – Caenorhabditis briggsae – was identified in the municipality of Itabaiana. Specimens of other mollusks species were also collected. Only one of these mollusks, C. fasciata from Japaratuba, was found infected with free-living nematodes. A. fulica showed greater positivity for nematodes in the dry season, especially in the regions of Lower São Francisco River, Greater Aracaju and South Central Sergipe. The probability of infection increased when mollusks were larger and more recurrent in plots. Given that A. cantonensis is the etiological agent of EM and was found associated to A. fulica in four municipalities, it will be important to implement programs of continuous monitoring of the mollusk's fauna, combined with educational programs that provide information necessary to control A. fulica.

Use of plant extracts to control activities of the invasive giant African land snail Achatina fulica

Giant African land snails (Achatina fulica; GALS) are a highly invasive herbivore and pose serious threats to native species and that could disrupt ecosystems. Various botanical extracts have been used as molluscicides to control mollusks for pest management. We aimed to identify the effects of neem (Azadirachta indica) and titepati (Artemisia vulgaris) to reduce GALS activities and survival using solutions of fresh neem leaf and titepati leaf, bark, and root. We found a fast movement in the GALS only in the extraction groups while the lethargic movement was lower in mulching method. A significant association of control groups with different extraction groups along with mulching treatment (p<0.05) however, no differences were observed among different extractions at 2.5% and 5% concentrations. Among the treatments, Neem leaf at 5% concentration was found to be effective as it helped immobilize the samples after ten days whilst other treatments required minimum 14 days to be effective. We recommend further studies of titepati and neem as control agents to reduce crop and vegetable damage from GALS.

First report, morphological and molecular characterization of Caenorhabditis brenneri (Nematoda: Rhabditidae) isolated from the giant African land snail Achatina fulica (Gastropoda: Achatinidae)

First report, morphological and molecular characterization of Caenorhabditis brenneri (Nematoda: Rhabditidae) isolated from the giant African land snail Achatina fulica (Gastropoda: Achatinidae)

Genetic characterization of Angiostrongyluslarvae and their intermediate host, Achatina fulica, in Thailand.

Angiostrongyliasis is a parasitic disease caused by nematodes of the genus Angiostrongylus. Distribution of this worm corresponds to the dispersal of its main intermediate host, the giant African land snail Achatina fulica. Genetic characterization can help identify parasitic pathogens and control the spreading of disease. The present study describes infection of A. fulica by Angiostrongylus, and provides a genetic outlook based on sequencing of specific regions. We collected 343 land snails from 22 provinces across six regions of Thailand between May 2017 and July 2018. Artificial digestion and Baermann's technique were employed to isolate Angiostrongylus larvae. The worm and its intermediate host were identified by sequencing with specific nucleotide regions. Phylogenetic tree was constructed to evaluate the relationship with other isolates. A. fulica from Chaiyaphum province was infected with A. cantonensis, whereas snails collected from Phrae and Chiang Rai provinces were infected with A. malaysiensis. The maximum likelihood tree based on 74 A. fulica COI sequences revealed monophyletic groups and identified two haplotypes: AF1 and AF2. Only AF1, which is distributed in all regions of Thailand, harbored the larvae of A. cantonensis and A. malaysiensis. Two mitochondrial genes (COI and cytb) and two nuclear regions (ITS2 and SSU rRNA) were sequenced in 41 Angiostrongylus specimens. The COI gene indicated that A. cantonensis was closely related to the AC10 haplotype; whereas the cytb gene revealed two new haplotypes: AC19 and AC20. SSU rRNA was useful for the identification of A. cantonensis; whereas ITS2 was a good genetic marker for differentiating between A. cantonensis and A. malaysiensis. This study provides genetic information about the parasite Angiostrongylus and its snail intermediate host. The data in this work may be useful for further study on the identification of Angiostrongylus spp., the genetic relationship between intermediate host and parasite, and control of parasites.

The Giant African Land Snail Achatina fulica (Bowdich, 1720) as a Candidate Species for Bioregenerative Life Support Systems

The Giant African Land Snail Achatina fulica (Bowdich, 1720) as a Candidate Species for Bioregenerative Life Support Systems

Assessing Geographic Conchological Variations of the Different Banding Patterns in the Invasive Giant African Land Snail Achatina fulica From the Philippines

 Abstract—Population of the invasive giant African snail Achatina fulica in the Philippines show conspicuous shell variations, which involve banding pattern, colour, size, and shape. Generally, shell shape and colour of land snails have been related to environmental factors. Therefore, the objective of this study is to determine and assess shape variations across population of geographically isolated shells with different banding patterns. Morphological analysis was performed on a total of 1309 matured shells from 15 different geographical locations across the Philippine island. Relative warp analysis revealed variation shell shape which could be slender-shaped or round-shaped. A variation in spire-whorl length coupled with aperture size was also observed. Canonical variance analysis scatter plot presented overlapping of populations from different geographical locations. Though there were no directly observable differences on the consensus shape superimposition of each geographically isolated population, results of multivariate analysis, Kruskal-Wallis test, and cluster analysis showed significant relationship of shell morphology of different banding patterns to geographical locations. However, the scattered distribution and short distance variation suggested a higher intrapopulation variation rather than interpopulation. Phenotypic plasticity, common in land snails, could be another explication for the observed intrapopulation conchological variations and that differentiation could also be due to multitude reactions to endogenous and exogenous factors.

Consequences of Aestivation in the Giant African Land Snail Achatina fulica Bowdich (Gastropoda: Achatinidae)

The consequences of aestivation in the giant African land snails Achatina fulica Bowdich occurring in Calcutta, India have been studied. It was noted that these snails under laboratory conditions, during aestivation had to face the hazards when the body weight was reduced by 50.33 %, the heart rate was reduced by 85 %, the oxygen consumption rate was reduced by 83 %, the blood sugar level was reduced by 50 %, the concentration on Ca++ and Mg++ ions was increased by 50 and 34 %, respectively, and the amount of haemolypmh protein was increased by 33 %, for survival. The effects were not much rigorous in aestivated snails in the field due to interruption of aestivation because of occasional shower. Though the snails, irrespective of size-groups had to face the consequences of aestivation, the extent of effect is very much influenced by the water content of the snail’s body concerned.

Factors inducing aestivation of the giant African land snail Achatina fulica Bowdich (Gastropoda: Achatinidae)

The giant African land snails Achatina fulica Bowdich occurring in Kolkata, West Bengal, India undergo aestivation with the advent of adverse conditions by the end of October or early part of November, each year. Experiments were conducted to study the factors inducing aestivation in these snails. It is revealed that the type of plant-foods, the length of starvation, the degrees of temperature and the percentages of relative humidity are the factors inducing aestivation in A. fulica of course, just at the onset of aestivation. It is also observed that, depending upon the severity of these factors the snails required different number of days to aestivate. Even, under similar situation individuals belonged to lower size groups started aestivation earlier than those of the snails belonged to higher size groups. The cumulative effects of certain above mentioned factors sometimes, either delayed or accelerated the process of aestivation.

First Record of Giant African Land Snail Achatina fulica from Rajasthan

First Record of Giant African Land Snail Achatina fulica from Rajasthan

Hydrogen peroxide generating alcohol and aldehyde oxidases in the giant African land snail, Achatina fulica

AbstractHydrogen peroxide generating alcohol oxidase (membrane bound) and aldehyde oxidase (cytosolic) were detected in tissues of the giant African land snail Achatina fulica. The highest specific activities were found in the kidney followed by the digestive gland. Solubilised digestive gland alcohol oxidase had a pH optimum of approximately 7.2. The enzyme oxidises a broad range of aromatic and aliphatic (C2C16) primary alcohols. Subcellular fractionation of digestive gland homogenate indicates that alcohol oxidase is most likely located in the endoplasmic reticulum. Cytosolic aldehyde oxidase was active with aromatic and aliphatic aldehyde but is not active with purines. A digestive role is suggested for these two enzymes. © Wiley‐Liss, Inc.