Adult Snails Research Articles

Phenotypic characteristics of native edible snails Achatina fulica and Archachatina marginata in equatorial region of Cameroon

Between February and May 2019, in the equatorial forest urbanized area of Cameroon (Mfoundi), a study was conducted and aimed to contribute on a better understanding of the biodiversity of edible snails for their genetic improvement and conservation. A total of 693 adult snails of two species: Archachatina marginata and Achatina fulica were collected in the various localities (Odza, Mbankolo, Biyem-assi, Nyom, Nkolbisson and Simbok). Information about biometric morpho characters was collected using a survey sheet, an electronic scale of 7000g capacity with accuracy of plus or minus 1g, a sliding foot with an accuracy of plus or minus 0.01 millimeter. A digital camera will be used for the subsequent morphological assessment of the animals. Results revealed significant influence of locality on all the morphobiometric characteristics. The shell color of A. marginata was black with yellowish stripes and the red tip was the most frequent (62.85%); while for the species A. fulica it was brown with white stripes and white tip (76.09%). The most common color of the foot in A. marginata was brown with white traces (41.70%) and in A. fulica, it was black (82.50%). The number of shell turns in A. marginata was higher in the localities of Mbankolo (5.36±0.12) and Odza (5.38±0.05) while in A. fulica it was higher in the locality of Simbok (7.41±0.49). Concerning body measurements (in mm), the total body length of A. marginata was higher in Nkolbisson (88.10±1.30) and that of A. fulica was greater in Simbok (112.25±12.16). The live weight (g) of A. marginata was higher in Mbankolo (70±0.00) on the other hand, that of A. fulica was higher in Simbok (80±0.02) and Nyom (80±0.12). The diversity observed suggests that edible snails constitutes rich natural genetic resources enough variability to envisage genetic improvement and develop preservation schemes for these snails mostly collected from wild

Shell morphology of golden apple snails (Pomacea canaliculata) from several rice fields in Bali, Indonesia

Golden apple snail (Pomacea canaliculata) has wide adaptability and rice fields are ones of the habitats for the snail. Golden apple snail has phenotypic variations. This study conducted to determine the morphology of golden apple snail from several rice fields in Bali, Indonesia. Samples were taken at twelve locations in three districts. Three rice fields were taken in each location. Samples were taken in quadrate plot of 1x1m at four points each rice field. The morphological of the golden apple snail samples were observed. The results showed that the golden apple snail shells found in all locations has a variety of colors. The color was yellowish to dark brown. The shell also has a shell band and the shell band vary in their appearance. The color of the shell band was more visible on the darker shell. Range of shell heights found in all locations was 8.7-61.5 mm. Most of the golden apple snails found in all location was adult snails.

An assessment of the molluscicidal potential of Cucurbita maxima seed extracts on Biomphalaria pfeifferi and Bulinus globosus snails

Reports of snails’ resistance to niclosamide appeared recently and finding new molluscicides becomes necessary. We investigated the molluscicidal effects of Cucurbita maxima seed extracts on Biomphalaria pfeifferi, and Bulinus globosus snails under laboratory conditions. For B. pfeifferi, we tested seed extracts on juvenile and adult snails while only adult B. globosus were available for testing. Snails were exposed to water and crude ethanol extracts for 72 h and significant concentration-dependent mortality rates were observed. The number of B. pfeifferi juveniles collected was not enough for a comprehensive investigation against both solvents. We, therefore, tested them against water extracts only. A lethal concentration of 0.02 mg/mL killed 50% of the snails (LC50) for both water and ethanol extracts on adult B. pfeifferi snails. Our results suggest that pumpkin seed extracts have a significant molluscicidal effect on B. pfeifferi and B. globosus snails. The LC50 values for all the extracts in B. pfeifferi and B. globosus snails are within the threshold set for potential molluscicides by the World Health Organisation. We propose that C.maxima seed extracts be considered as potential molluscicidal agents in Schistosomiasis transmission control.

Effect of Herbicides Used in Horticulture (2,4-D, Glyphosate and Nicosulfuron) on Snails <i>Achatina fulica</i> (Bowdich, 1720)

2,4-Dichlorophenoxyacetic (2,4-D), glyphosate, and nicosulfuron, because of their modes of action and selectivity, are the most widely used herbicides in Ivorian horticulture. Fuels toxicity was the reason of many debates in the world because of their massive and uncontrolled use. They are frequently blamed for the reduction of soil fertility and terrestrial biodiversity observed in agricultural areas. In view of the debates raised by their toxicities, the use of these herbicides requires the greatest caution and clear information on the real risk incurred by the edaphic fauna by conducting ecotoxicity studies. The present study aims to evaluate the effect of 2,4-D, glyphosate and nicosulfuron herbicides on the growth and reproduction of Achatina fulica snails in microcosm. To do this, we treated each plot on which snail microcosms were placed with 2,4-D, glyphosate or nicosulfuron herbicides according to the manufacturer’s recommendations. The results showed for all the herbicides used, that after 28 days of exposure, the growth of juvenile snails was slowed down. The number of eggs laid per pair was reduced in adult snails. The egg hatchability test revealed a reduction in egg hatchability. In addition, each effect was dependent on the herbicide used. Thus, toxicity was found to be greater according to the following order: nicosulfuron ? glyphosate ? 2,4-D. From the results obtained, we concluded that 2,4-D, glyphosate, and nicosulfuron treatments under field conditions are a potential threat to the sustainability of snail species and therefore to soil life. The intensity of the effect depends on the toxicity of the herbicides used.

Influence of breeds and number of whorls on phenotypic traits and correlations among giant African land snails in Nigeria

Six hundred adult mature black-skinned snails with four and five whorls on the shellcomprising of 200 each of the breeds; Archachatina marginata, Achatina achatina and Achatina fulica were used for the study. Phenotypic traits measured from the snails included body weight (BDW), shell length (SHL), shell width (SHW), aperture length (APL), aperture width (APW), spiral length (SPL), spiral width (SPW), diagonal length (DAL), length between the aperture and first spiral (LAS). The data obtained were used to estimate simple statistics (mean, standard error and coefficient of variations) and correlation oefficients. The results showed high significant (p<0.01) breed effects on phenotypic traits as A.nmarginata snails with four (288.700g) and 5(394.500g) whorls were phenotypically and genotypically heavier, larger and wider than A. achatina (127.0g and 182.000g) and A. fulica (48.850g and 65.050g) with four and five whorls respectively. There were also high significant (p<0.01) disparity number of whorls effects on body weight and other phenotypic traits studied. There was only one strong, negative and significant (p<0.01) phenotypic correlation (r ) between SHL and LAS (r = – 0.650) recorded for A. achatina snails with four whorls while A. achatina snails with five whorls recorded few strong, negative and significant(P<0.01) phenotypic correlations between BDW and SHW (r = – 0.613), SHL and LAS (r = –0.641), SHW and APW (r = – 0.602). Similarly, A. fulica snails with four whorls recorded few strong, negative and significant (p<0.01) phenotypic correlations between BDW and SHW (r = – 0.627), SHL and APL (r = – 0.639), SHW and APW (r = – 0.657) and only one strong, negative and significant (p<0.01) phenotypic correlation between SHL and LAS (r = – 0.605) for A. fulica snails with five whorls. Again, Am snails with four whorls had only one strong, negative and significant(p<0.01) phenotypic correlation between BDW and SHL (r = – 0.720). The only two low, positive and significant (p<0.05) phenotypic correlations recorded in this study were between APL and APW ((r = 0.544) and between SPL and DAL (r = 0.583) for A. marginata snails with four and five whorls respectively. Thus, the breed type and number of whorls on snail shells strongly influenced estimates of phenotypic traits and correlation coefficients of giant African land snails in Nigeria. Also, that estimates of correlation coefficients of mature giant African land snails with higher whorls were (4 and 5) are scarcely strong, positive and significant. The study revealed and confirmed that A. marginata snails are phenotypically and genotypically heavier, larger and wider than A. achatina and A. fulica snails with 4 and 5 whorls. These estimates are recommended as strong and efficient tools for selection and up grading or improvement of giant African land snails genetic traits in Nigeria.

How do developmental and parental exposures to predation affect personality and immediate behavioural plasticity in the snail Physa acuta?

Individuals differ in personality and immediate behavioural plasticity. While developmental environment may explain this group diversity, the effect of parental environment is still unexplored-a surprising observation since parental environment influences mean behaviour. We tested whether developmental and parental environments impacted personality and immediate plasticity. We raised two generations of Physa acuta snails in the laboratory with or without developmental exposure to predator cues. Escape behaviour was repeatedly assessed on adult snails with or without predator cues in the immediate environment. On average, snails were slower to escape if they or their parents had been exposed to predator cues during development. Snails were also less plastic in response to immediate predation risk on average if they or their parents had been exposed to predator cues. Group diversity in personality was greater in predator-exposed snails than unexposed snails, while parental environment did not influence it. Group diversity in immediate plasticity was not significant. Our results suggest that only developmental environment plays a key role in the emergence of group diversity in personality, but that parental environment influences mean behavioural responses to the environmental change. Consequently, although different, both developmental and parental cues may have evolutionary implications on behavioural responses.

Estimating growth, size-dependent mortality, and tag loss in a mark-recapture study: demography of wavy turban snails in Southern California, USA

Tagging studies are often used to measure survival and growth in wild populations. However, issues such as low returns of tagged animals, tag loss, and handling mortality can affect the precision and accuracy of demographic estimates if not accounted for. We conducted a mark-recapture study to measure the survival and growth of juvenile and adult wavy turban snails Megastraea undosa. Our study highlights several methodological advances, including a method for estimating a single growth function by analyzing the joint changes in length and weight of tagged animals; a simple method for estimating rates of tag loss when some animals are double tagged; and a way to estimate handling mortality by comparing encounter histories of animals immediately after tagging and after several weeks in the field. Tag loss was moderate (≈15% over a 100 d period) and handling mortality was substantial during the fall (≈55%), but negligible during the spring. If we did not account for tag loss and handling mortality, our estimate of survival would have been severely underestimated (≈46% lower over a 100 d period). After accounting for such effects, our study revealed that survival probably increased sharply with body size, but survival did not differ among seasons. These snails are slow-growing, mature after approximately 6 yr, and can routinely grow to >10 yr old. There is an emerging fishery for this species, and because our results suggest that the oldest snails have a very high reproductive value, measures that protect these large individuals are likely to be beneficial for the resilience of these populations.

Comparing Trace Element Bioaccumulation and Depuration in Snails and Mayfly Nymphs at a Coal Ash-Contaminated Site.

We examined the bioaccumulation of essential (Cu, Fe, Se, and Zn) and nonessential (As and Hg) trace elements in 2 aquatic invertebrate species (adult snails and mayfly nymphs) with different feeding habits at the site of a coal ash spill. Differences in food web pathway, exposure concentrations, and biological processing affected bioaccumulation patterns in these species. Mayflies had higher body burdens, but snails had higher retention of most elements studied. Environ Toxicol Chem 2020;39:2437-2449. © 2020 SETAC.

Nomads of northern coasts: distribution of <i>Aporrhais pespelicani </i>(Gastropoda: Stromboidea) in the Barents Sea

Gastropod Aporrhais pespelicani was recently recorded for the first time in several localities along the Murman Coast (SW Barents Sea). In all areas, only single specimens were collected with the exception of Kislaya Inlet where the dense population was found. We repeated field study in the Kislaya Inlet decade later after the first findings of the species. No living specimens were found at the place of the previous habitat of the population of Aporrhais pespelicani, however, two adult snails were collected in a remoted locality from the same waterbody. We hypnotize that distribution of Aporrhais pespelicani in the its northern edge of range fit to “core-satellite” metapopulation model, where Murman local populations representing “satellites” of the Norwegian “core”. There is no evident proof on the relation of recent records of Aporrhais pespelicani with range extension due to the climate change, as it was suggested before.

Eobania vermiculata as a potential indicator of nitrate contamination in soil

The effects of nitrates were analysed on the land snail Eobania vermiculata, a good bioindicator to assess the effects of certain pollutants in soil. It is known that the molluscs are very sensitive to contamination substances and can be used as sentinel organism for environmental pollution assessment. The nitrates are present in fertilizers and in food additives and their excess can not only be harmful to the environment but also dangerous for the humans. Indeed, in the mammals the nitrates are converted into nitrites and can cause a series of complications as the formation of methaemoglobin and cancers. In this study, adult organisms of E. vermiculata were exposed to soil containing 2000 mg/L of nitrates for 30 days to evaluate the stool microbiome and the histological changes at the level of the foot. Eggs of these snails were similarly treated to observe their hatching, survival and development. Histological changes were observed at level of the foot of adult snails exposed to nitrate and in their stools was evident an increase of bacteria, especially those that have a high ability to exploit nitrates and nitrogen as nutrients. Instead, the treated eggs showed changes in hatching, hypopigmentation of newborn snails and a decrease of their survival in time. The overall information obtained from these endpoints can provide important information regarding the quality of the environment. In addition, they also showed that the invertebrate organism E. vermiculata despite being a simple organism is very useful and efficient for ecotoxicological studies.

Molluscicidal Assessment of Aqueous Extract of Moringa oleifera Lam Seed on Bulinus Snail for the Control of Schistosomiasis

Aims: This research is essentially on the Molluscicidal assessment of Aqueous extract of Moringa oleifera Lam seed on Bulinus Snail for the control of Schistosomiasis.
 Study Design: This is a controlled study where a total of 810 Bulinus snails were collected from three different streams with each stream representing a community from each of the three senatorial zones of Anambra state where schistosomiasis was endemic. Aqueous extract of Moringa oleifera (Lam) seed at different concentrations were used on the Bulinus snails to determine their molluscidal properties.
 Place and Duration of Study: Two hundred and Seventy (270) Bulinus snails were collected from streams representing each of the three senatorial zones of Anambra state viz; Obutu Lake, Omogho town, Orumba North Local Government Area (Anambra South), Agulu Lake, Agulu town, Aniocha Local Government Area (Anambra Central) and Omambra River, Omor town, Ayamelum Local Government Area (Anambra North) This research was carried out between November 2018 to April 2019.
 Methodology: Aqueous dilutions of the grinded Moringa oleifera (Lam) seed were exposed to the Bulinus snails from the various streams for 24 hours, after which the snails were removed from the experimental test solution and washed thoroughly with dechlorinated tap water and transferred to containers with fresh dechlorinated tap water for another 24 hours of recovery. The snails were incubated at 28 ± 5°C and fed with lettuce leaves.
 Results: Aqueous Moringa oleifera Lam seed extract was toxic to Bulinus adult snails in a dose dependent manner and the total Lethal Concentration (LC50 and LC90) values determined after 24 hours exposure from the whole streams were 468 ppm and 813 ppm respectively.
 Conclusion: Aqueous seed extract of Moringa oleifera Lam was toxic to Bulinus snail even at low concentrations.

Effets aigus de l’exposition à la tartrazine (E102) sur le comportement et l’histologie d’un modèle biologique l’escargot terrestre Helix aspersa

Introduction. Tartrazine is an azofood additive widely used in the pharmaceu-cal, cosmetic, food, and other industries. Objective. To assess the effects of tartrazineon the attitude to move and to eat, and histological changes in digestive, and renal sys-tem, after an acute treatment on a biological model the snail Helix aspersa. Material and Methods. Snails were exposed orally, and by contact to flour contaminated with this dye for 24 hours. Adult snails were divided into two groups of 20 animals each. The control group fed flour alone. The experimental group was administered orally with flour treated with tartrazine (200mg/g flour). Results. The observation of behaviour revealed inhibitory effects of tartrazine on locomotion, and nutrition of snails. Histolo-gical examination of intestines, hepatopancreas, and kidney of treated animals showed altered tissue structures, with advanced degeneration of digestive tubules, connective tissue, and smooth muscle fibers of the walls surrounding the three organs, in response to tartrazine, compared to controls. Conclusion. This study suggests that acute exposure to tartrazine may lead to disorders in locomotor, and nutritional behavior, in addition to tissue alterations. Therefore, this study on behavior, supported by histological changes in H. Aspersa can be used as potential biomarkers of exposure to other azodyes.

Redefining operant conditioning of escape behaviour in Lymnaea stagnalis

The escape behaviour is one of the many behavioural responses that can be operantly conditioned in a stimulus-dependent manner in both vertebrates and invertebrates. By exposing the pond snail Lymnaea stagnalis repeatedly to a negative reinforcement its natural tendency to explore its surroundings can be operantly conditioned in both adult and aged snails. When adult snails were trained with 100 mM of KCl their number of escapes was significantly decreased and the latency to first escape was significantly increased. Our behavioural protocol allowed us to investigate memory acquisition, consolidation, and retrieval in pre- and post-training sessions over different days. From the 3rd day of training the learned response was strengthened: the number of the escapes in the post-test session remained significantly reduced even when animals were presented with distilled water. Moreover, adult snails exposed to the negative reinforcement for at least 4 days started to escape significantly less than the control group also in the pre-test session. This effect became more pronounced in the following days and was accompanied by a significant increase in the latency to first escape at the beginning of the pre-test on day 6 and 7. Aged snails, instead, showed selective deficiencies when operantly conditioned: memory retention appeared only after 7 days, while memory retrieval could not be induced. This redefined paradigm can help unravelling a variety of sophisticated cognitive phenomena in L. stagnalis and could be employed also to study the basis of memory impairment occurring during neuro-aging.

Effects of salinity on survival, growth and reproduction of the invasive aquatic snail Pomacea canaliculata (Gastropoda: Ampullariidae)

Pomacea canaliculata, a freshwater snail native to tropical and temperate South America, has become an important invader and agricultural pest throughout tropical and subtropical regions around the world. Colonization of various aquatic habitats by P. canaliculata in coastal regions of South China and its establishment potential in estuaries have raised great concern, yet little is known about the biological response of the snail and its tolerance under saline environments. We first examined the salinity tolerance of P. canaliculata using a total of 30 experimental juvenile snails exposed to eight salinity levels (from 0 to 14 psu in 2 psu steps). Daily survival of the snails was measured for each salinity treatment over 30 days. Based on salinity exposure test, influence of salinity on snail reproduction was investigated for a period of 30 days using 30 adult snails exposed to four salinity treatments (0, 2, 4 and 6 psu). Each salinity test replicated three times. Pomacea canaliculata could tolerate salinity levels ranging from 0 to 6 psu in which probability of survival was greater than 72% during a 30 days exposure. Lethal time leading to 50% mortality (LT50) of the snail declined from 71 days at 0 psu to 27 days at 6 psu. Pomacea canaliculata could ingest and reproduce normally at salinities ranging from 0 to 4 psu. Average mass daily gain, specific growth rate, and the hatching of egg clutches decreased significantly with elevated salinities. Results show a general threshold response of P. canaliculata to salinity. This freshwater snail falls into “2nd degree” euryhaline limnobionts tolerating salinities of 3–8‰.

Evaluation of the Molluscicidal, Artemicidal and Cytotoxic Activities of the Lectin from Opuntia ficus-indica Cladodes (OfiL)

Background: Biomphalaria glabrata is an intermediate host for the larvae of Schistosoma mansoni, which is distributed widely in the tropics. B. glabrata control is important to minimize the spread of schistosomiasis and natural compounds have been sought for use against this disease. The Artemia salina bench-top bioassay has been used to investigate the ecotoxicity of many natural compounds, and its results also correlate well with the in vitro cytotoxicity of natural compounds to tumor cells.
 Aims: To evaluate deleterious effects of the Opuntia ficus-indica lectin (OfiL) on B. glabrata, A. salina and human cancer cell lines.
 Methods: OfiL was isolated following a previously established protocol. The effects of OfiL on B. glabrata were investigated by determining survival of adults as well as development and hatching of embryos. The concentration required to kill 50% (LC50) of A. salina nauplii was determined. The cytotoxicity was determined using the human cell lines Hep-2 (human larynx epidermoid carcinoma), NCI-H292 (human lung mucoepidermoid carcinoma) and K562 (chronic myelocytic leukemia).
 Results: The development of most embryos (92.5–97.5%) treated with 1, 10 and 100 µg/mL of OfiL was found to be delayed, and dead (2.2–3.3%) and malformed (0.3–5.2%) embryos were also observed. OfiL did not kill B. glabrata adults, but a high percentage (30–45%) of the embryos generated by snails incubated with the lectin exhibited malformations. OfiL exhibited toxicity against A. salina (LC50: 61.02 µg/mL) but did not display cytotoxicity against the tumor cell lines evaluated.
 Conclusion: In conclusion, this study showed that OfiL can be a tool for schistosomiasis control that acts by impairing the viability of B. glabrata eggs and the fecundity of adult snails.

Temperature Impacts on the Cardiac Activity of the Snail Pomacea canaliculata from Shatt Al-Arab Region, Basrah, Iraq

The effects of temperature on an exotic aquatic snail Pomacea canaliculata (Lamarck, 1819) collected from the Shatt Al-Arab intertidal zone were investigated. A series of laboratory experiments were conducted during the summer period of 2017. Individuals of new born snails hatched in the laboratory from adult snails were collected from Shatt Al-Arab intertidal zone, and subjected to five fixed temperatures: 15, 25, 35, 40 and 45 Cº, after short term thermal acclimation. The heartbeats (HB) were counted at each temperature level. The results showed significant direct increase of HB from 15 Cº (19.8 HB/min) up to 25 Cº (76 HB/min) (P<0.05) as well as from 25 Cº to 35 Cº (93 HB/min). At 40 Cº the snail HB shows only slight insignificant increase (79 HB/ min). At 45 ºC the HB became irregular and showed negative thermo cardiac activity (HB dropped to 50.4/min). The minimum HB rate of 11/min was recorded at 15 Cº and the maximum value of 119 HB/min was recorded at 40 Cº. The study concluded that P. canaliculata can be highly stressed when exposed to extreme temperature experienced during the prolonged summer months and will no longer tolerate living in the intertidal zone of Shatt Al-Arab.

Assessment of the molluscicidal activity of wormwood (Artemisia dubia, Wallich) leaves ethanolic extract on Oncomelania hupensis quadrasi, Möllendorff

This study assessed the in vitro molluscicidal activity of Artemisia dubia (wormwood) leaf ethanolic extract against adult and juvenile Oncomelania hupensis quadrasi and profiled its qualitative phytochemical content. The plants and snails were collected locally. There were 8 concentrations used for adult and juvenile snails: distilled water and 1% ethanol as negative controls; niclosamide (2 mg/L) as a positive control; and different concentrations of wormwood ethanolic extracts for adult snails including 3.98% (T1), 4.46% (T2), 5% (T3), 5.61% (T4), and 6.30% (T5) and for juvenile snails including 7.94% (T1), 8.91% (T2), 10% (T3), 11.22% (T4), and 12.59% (T5). Each treatment was replicated 5 times with 20 snails per replicate. Results showed that the concentrations that were statistically comparable with niclosamide (2 mg/L) were 6.30% (T5) with 92% mortality for adults and 10% (T3), 11.22% (T4), and 12.59% (T5) for juveniles with 94%, 95%, and 98% mortality, respectively (P > 0.05). The qualitative phytochemical tests for secondary metabolites revealed the presence of tannins, saponins, and terpenoids. Independently or in combination, these secondary metabolites may be responsible for the mortality of the snails. This study indicates the possibility of using wormwood ethanolic extract as a potent and a possible alternative for synthetic molluscicides.

Ecotoxicology and environmental safety toxicity of pyrethroid cypermethrin on the freshwater snail Chilina parchappii: Lethal and sublethal effects.

The aim of the present work was to study the effect of the pyrethroid cypermethrin (CYP) on the non-target freshwater snail Chilina parchappi. Initially, the sensitivity of adult snails to CYP was evaluated via the 96-h LC50 test. Then, snails were exposed to subtethal CYP concentrations (0.1 and 10mg/l) for 1, 4 and 10 days and the digestive glands were dissected for biomarkers analyses. Enzymatic activity of catalase (CAT), glutathione peroxidase (GPx) and glutathione-S-transferase (GST), as well as total glutathione reduced (GSH) levels, were determined. Histological analyses of morphology, intracellular accumulation of lipofucsins and neutral lipids accumulation in the digestive gland were also evaluated. As compared to other molluscs, C. parchappi showed high resistance to CYP exposure evidenced by the 96-h LC50 value (44.59mg/l). Snails exposed to sublethal CYP concentrations showed a statistically significant increase (p<0.01) in GST (79-116%) and GPx (45-190%) activities with respect to controls. However, CAT activity showed a tendency to decrease with CYP treatment but was not statistically significantly different compared to control. Only high CYP concentration caused a statistically significant increase (p<0.01) in GSH content (95-196%). There was evidence of structural changes in the digestive gland of snails exposed to CYP, showing a dose-dependent response. In exposed snails, some of the main symptoms included a reduction in the thickness of the epithelium, vacuolisation of the digestive cells and an increase in the number of excretory cells. Accumulation of lipofuscins (933-1006%) and neutral lipids (403%) were statistically significantly higher (p<0.05) in snails exposed to CYP compared to control. This study showed that C. parchappii is quite tolerant to CYP exposure and that at sublethal concentrations, GSH metabolism could play a protective role against the pesticide harm in snails. Therefore, it would be interesting to study the response of this organism to other environmental stressors to assess its potential use in monitoring programs.

Study on the Development of Spiral babylonia snail Tiger Snail Juvenil Eggs (Babylonia spirata Linnaeus, 1758) in the Laboratory

Several marine gastropods are known to have high economic value, one of which is the Spiral babylonia snail. They commonly exploited for meat, shell, or operculum. Tiger snail meat is commonly exported and consumed by fishermen. Its shell is used as a material for industrial lime and for omamen. Operculum is commonly used as a medicinal and perfume ingredient). However, the recent production has decreased due to the limited information of seasonal catch. One way to overcome these obstacles is through culture activities. The provision of seeds is an important link in the culture system, therefore the study of the spawning process and larval development is an important requirement for the development of larval rearing techniques. This study aims to determine the development process of juvenil eggs and the survival rate of tiger snails reared in the laboratory.. The study was conducted at the Laboratory of Marine Farm Subdivision in Kudus, Pt Pura Bahari, Jepara Regency. This sudy used experimental method with descriptive data analysis. Adult tiger snails were caught from Bunga waters, Demak. The snails were reared in a rectangular tube filled with 15 cm filtered sea water and 5 cm of sand. Egg capsules were reared in a 4 liters circular tube with continuous aeration. The hatched larvae were reared in a 300 liters circular tube filled with filtered seawater, continuously aerated and fed with Chlorella plankton . Our result showed that tiger snails spawn naturally and produce egg capsules. The incubation period for the capsule is 6 days, then develop into veliger larva for 12 days. The veliger larvae metamorphosed,and become juvenil. The lowest survival rate observed in the veliger stage. The survival rate of the egg and the intracapsular trochopore stages were quite high (tube I = 98.413%; tube II = 98.238%; tube III = 90.476%), then the lowest was in the veliger stage (tube I = 3,468%; tube II = 2.603%; tube III = 2,598%) and the juvenil stage is quite high compared to the previous phase (tube I = 3,413%; tube II = 2,479%; tube III = 2,351%).

Survival analysis of laboratory - bred smooth - shelled Oncomelania snails in Yunnan Province

To investigate the survival period of Yunnan Province-derived smooth-shelled Oncomelania snails bred in laboratory. Oncomelania snails were sampled from Heqing and Yongsheng counties where schistosomiasis is endemic, and uninfected adult snails were collected and bred in laboratory. The survival period of snails sampled from these two counties was compared. The 1-, 2-, 3- and 4-year survival rates of laboratory-bred smooth-shelled snails sampled from Yunnan Province were 72.36%, 29.11%, 13.08% and 0.21%, respectively, and were 74.66%, 38.91%, 19.46% and 0.45% for snails derived from Heqing County, and 70.36%, 20.55%, 7.51% and 0 for snails sampled from Yongsheng County, respectively. The mean and median survival period of Yunnan Province-derived adult snails was 20.90 and 20.67 months, and there were significant differences between the snails sampled from Heqing and Yongsheng counties in terms of the mean (22.94 vs. 19.13 months, P < 0.05) and median survival period (21.63 vs. 19.81 months, P < 0.05). The mean survival period of Yunnan Province-derived smooth-shelled adult snails is approximately 20 months in laboratory, and the survival varies in geographical areas.