Pila Globosa Research Articles

Water quality and the presence of metals in crustaceans (Sartoriana spinigera) and mollusks (Pila globosa) close to an urban waste landfill in Kodda at Gazipur

Degradation of water and sediment quality along with other aquatic ecosystem components, due to urban waste is a significant concern that demands attention. Despite of the multifaceted use of the Konabari area within the Gazipur City Corporation of Bangladesh, limited studies have assessed the health of the floodplain ecosystem adjacent to urban waste landfills in Kodda. This research focuses on evaluating water quality parameters and the presence of metals and metalloids in water, sediment, and biota (invertebrates) in the lowland floodplain near the Kodda municipal landfill in Gazipur district. In December 2022, thirteen composite samples, including water, sediment, crustaceans (Sartoriana spinigera), and mollusks (Pila globosa), were collected from the designated sampling site. Surface and sub-surface (0–15 cm depth) water were collected using a water sampler for water quality analysis, and the presence of heavy metal and metalloid content of the water, sediment, crabs, and mollusks were analyzed using an atomic absorption spectrometer. The results indicated dissolved oxygen concentrations ranging from 0.30 to 5.81 mg/l (mean 3.1±2.37 mg/l). Certain locations directly affected by waste discharge exhibited alarmingly low dissolved oxygen levels (~0.71 mg/l), coupled with elevated temperatures and phosphate (PO43−) content (2–7.4 mg/l). The scarcity of heavy metal concentrations (<0.0677 mg/l) in water may be attributed to the constant flow of water preventing metal accumulation in the flowing water. However, sediment analysis revealed significantly higher concentrations (mean±Sd) of Fe (15240±1211 mg/kg), Mn (1122±180 mg/kg), Cu (44±5.5 mg/kg), Cr (28±3.2 mg/kg), Ni (39±2.4 mg/kg), As (3.7±0.89 mg/kg), and Zn (72±3.95 mg/kg) compared to other studies in various locations. Crustacean (Crab) samples showed concentrations of Cr, As, Pb, Cd, Zn, and Cu exceeding recommended permissible limits. Pila globosa emerged as an effective ecological bioindicator of aquatic pollution, with concentrations of Cr, Mn, Ni, Cu, Zn, and Pd exceeding recommended limits. Despite eco-environmental indices suggesting low to moderate contamination, the heavy metals and metalloids study indicated degradation of ecosystem health triggered by urban waste discharge. Consequently, the study recommends proper waste treatment in landfills and their transformation from open dumps to scientifically managed controlled waste landfills. Ann. Bangaldesh Agric. 27(2):175-189

The shells of edible freshwater snails as a biosorbent for multi-metal ions from wastewater: Implication in effluent purification and waste valorisation

The generation of waste shells of edible freshwater snails, Filopaludina bengalensis and Pila globosa, following human consumption and use in aquaculture, encourages their utilisation as a potential biomaterial. In this experiment, we employed the shell dust derived from F. bengalensis (FSD) and P. globosa (PSD) shells as a biosorbent of Cd2+, Co2+, Cr2O72- and Cu2+ from single- and multi-metal solutions. The results of batch adsorption experiments and characterisation of FSD and PSD using SEM, EDS, ICP-OES, FTIR, and XRD indicated that the metal ion removal process involved chemical adsorption (formation of CdCO3, Cu2CO3(OH)2 and CoCO3), ion exchange (reduced quantity of various elements on the shell dust following their release into the solution during adsorption) and surface precipitation. The best-fitted Langmuir isotherm specified monolayer adsorption with maximum adsorption capacity for Cd2+ (in single-metal system: FSD- 254.42, PSD- 327.76 mg/g; in multi-metal system: FSD: 93.79, PSD: 94.45 mg/g) and Cu2+ (in single-metal system: FSD- 234.63, PSD- 289.71 mg/g; in multi-metal system: FSD: 150.01, PSD: 160.51 mg/g). In multi-metal systems, the adsorption of Cd2+ and Cu2+ was antagonistic, and the adsorption of Co2+ and Cr2O72- was synergistic in nature. The thermodynamic parameters suggest that the adsorption is endothermic, feasible and spontaneous. The successful removal of metal ions from single- and multi-metal solutions and real wastewater recommended FSD and PSD as eco-friendly and low-cost biosorbent for wastewater amelioration with implication in waste valorisation.

Freshwater shellfish, Pila globosa: a review on its ecological and economical importance, nutritive and ethno-medicinal values

The freshwater Indian apple snail, Pila globosa (Swainson, 1822), is well adapted to the equatorial and tropical regions of the planet, where there are periods of heavy rain that are followed by dry spells. It is the most important biotic component of the ecosystem and a dominating member of its communities, making it crucial for the health of the ecosystem. It has a significant economic importance in the international trade market. The flesh of P. globosa is used in aquaculture and as a human protein supplement because of its high protein and low fat content, along with essential fatty acids. The shell of P. globosa is a good source of minerals, especially calcium. P. globosa has been employed in traditional medicinal practices to treat diseases like high blood pressure, heart disease, asthma, rickets, rheumatoid arthritis, osteoporosis, calcium metabolism, bleeding piles, constipation, diarrhoea, smallpox, syphilis, dizziness, anxiety, nervousness, urticaria, night blindness, and conjunctivitis. It is also used to regulate body temperature, to speed up wound healing, to treat circulatory issues, to revive virility and vitality, to treat weakness, and for vision improvement. P. globosa has antimicrobial, anti-inflammatory, anti-oxidative, anti-cancer, and immune boosting properties, and it can be a benefit to mankind. This review provides an overview of the ecological and economic importance, nutritional and ethno-medicinal values of the snail P. globosa.

DNA Barcoding and Phylogenetic Analysis of Some Gastropod Molluscs (Class-gastropoda) from Three Ecological Habitats of Bangladesh

An attempt has been made for molecular characterization of gastropods from three different ecological habitats (marine, freshwater and terrestrial) in Bangladesh. A total of eight species of gastropod (Lissachatina fulica, Pila globosa, Pila virens, Brotia costula, Nerita articulata, Nerita balteata, Macrochlamys indica and Telescopium telescopium) were identified belongs to seven genera and six families. These species were confirmed through morphological studies and by adopting DNA barcoding using mitochondrial cytochrome c oxidase subunit I (COI) and 16S ribosomal RNA (16S rRNA) gene. The average GC content 39.53% and 33.40% were found for COI and 16S rRNA, respectively. Genetic divergence increased as predicted with higher taxonomic rank, ranging from 0% to 2.84% with an average 1.45% within species and 3.57% to 35.23% between species with a DNA barcoding gap of 0.73 for 16S. This study revealed that gastropod species can be discriminated using both COI and 16S rRNA gene. Phylogenetic relationships among identified species were established where individuals belonging to the same species were grouped under the same clade. Molecular characterization of remaining molluscan species of Bangladesh remains to be completed.
 Bioresearch Commu. 9(2): 1305-1309, 2023 (July)

MORPHOLOGY OF PILA GLOBOSA (GASTROPOD MOLLUSCA: AMPULLARIIDAE) WITHIN ENVIRONMENTAL VARIATION OF SOUTH-WESTERN BANGLADESH

Owing to the community engagement of the gastropod collection in the south western ecosystems in Bangladesh, the gastropod molluscs are getting important attention in terms of edible and non-edible purposes while detailed morphological information about the gastropods is scarce in this area. The present research has investigated the morphological variability of the gastropod molluscs (Pila globosa) in the six localities of south-western coastal Bangladesh (such as, Khulna, Bagerhat, Satkhira, Gopalganj, Pirojpur and Jessore). A total of 2160 gastropod samples (Pila globosa) were collected from July to December monthly over the two consecutive years of 2013 and 2014. The results of the analyses revealed that the maximum monthly mean values of the dry shell mass and the dry body mass were found in November, indicating the complete growth and development of the gastropods in the coastal environment. One-way ANOVA and ANCOVA show that there is a significant morphological variability of Pila globosa among different localities in the south-west coastal Bangladesh, while the covariate of water salinity significantly affects the aperture length of it; the covariate of electrical conductivity of soil significantly affects both the height and aperture length; the covariate of sodium contents of the soil significantly affects the aperture length of the gastropod mollusc. The results also revealed that the morphological variability of the mollusc P. globosa is linked to complex ecological systems and habitat variation.

Filtration capabilities of freshwater mussel (Lamellidens marginalis) and apple snail (Pila globosa) and their potential impacts on freshwater integrated multitrophic aquaculture systems

Aim: The study aimed to assess the relative filtration rates of an indigenous freshwater mussel, Lamellidens marginalis and an indigenous freshwater snail, Pila globosa, and their suitability for incorporation into freshwater integrated multi-trophic aquaculture (FIMTA) systems. Methodology: An indoor experimental trial was conducted in a wet laboratory (temperature: 30.5 ± 0.5, light intensity: 2000 lux, light cycle: L: D: 12hr: 12hr). The trial was performed in glass aquaria in triplicate filled with algae rich water to assess their filtration rate. Simultaneously, the impacts of these two molluscs on inorganic nitrogen and phosphorus were evaluated. Results: L. marginalis exhibited filtration rates of 934.7± 0.07 cells min-1 mussel-1 and 13.79 ± 0.04 cells g-1 min-1) against 261.8 ± 10.15 cells min-1 snail-1 and 9.74±0.15 cells g-1 min-1 for P globosa. Similarly, the mussel also exhibited markedly higher turbidity and chlorophyll clearance capacity (p<0.05) in comparison to snail, especially during initial 6-12 hr when initial concentrations of algal population, turbidity and Chl-a were high. Notably, the oxygen consumption and ammonia excretion rates were greater for snail than mussel after 24hr and at the end of the experiment. Interpretation: The results provide quantitative information on the filtration capacity of two indigenous freshwater molluscs that have considerable local food as well as economic value and would pave the way for their utilization as ecological engineers, especially organic extractive in freshwater integrated multi-trophic aquaculture (FIMTA) system. It is concluded from the study that L. marginalis was more efficient in extracting almost four times algal cells than, P. globosa. Key words: Eutrophication, Filtration, Lamellidens marginalis, Pila globosa

Crystallographic characterization of naturally occurring aragonite and calcite phase: Rietveld refinement

This research has comprehended the crystallographic characterization of two naturally occurring calcium carbonates phases e.g. aragonite and calcite in Pila globosa (P. globosa) and eggshells respectively. The tools employed to confirm the phases of aragonite and calcite were X-ray diffractoion (XRD) and Fourier Transform Infrared (FT-IR) spectroscopy. Several important crystallographic parameters like crystallite size, lattice parameters, dislocation density, crystallinity index, microstrain, volume of the unit cell, relative intensity of a certain plane, preference growth, and specific surface area were taken into account while assessing the desired aragonite and calcite phases. A number of well-known models e.g. Straight-line model of the Scherrer model, the Monshi-Scherrer model, the Williamson-Hall model, the Sahadat-Scherrer model, and the three-peak model aided the estimation of crystallite size. In all the cases, the observed crystallite size of calcite was larger than that of aragonite. The percentage of calcite and aragonite in eggshell and P. globosa were assessed by Rietveld refinement method. Observed results revealed that 97.4% calcite and 2.6% aragonite phases are present in eggshell while in P. globosa these percentages exist inversely, i.e. 93.2% aragonite and 6.8% calcite phases.

Consumption of Pila globosa (Swainson) collected from organophosphate applied paddy fields: human health risks.

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 (1.5mll-1 water) and high (2.5mll-1 water) agricultural doses for 48h 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 1.53µgl-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. 27µgl-1, respectively, for 3-48h. In the foot tissue, residues ranged from 4.36 to 15.54µgkg-1 for low-dose CPF, 7.1 to 18.05µgkg-1for high-dose CPF and from 5.28 to 12.3µgkg-1 and 8.94 to 18.21µgkg-1 for low and high dose of MCP, respectively, during 3 to 48h 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.

"In-vitro Effects of Chlorpyrifos and Monocrotophos on the Activity of Acetylcholinesterase (AChE) in Different Tissues of Apple Snail Pila globosa (Swainson, 1822)"

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.

Temporal morphometric analyses of Pila globosa in India for its use in aquaculture and food industry

BackgroundAlthough 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.ResultsThe 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.ConclusionThe 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.

Probiotic characterization and cholesterol assimilation ability of Pichia kudriavzevii isolated from the gut of the edible freshwater snail “Pila globosa”.

Excess cholesterol is one of the main causes of various metabolic diseases. Currently available therapeutic measures, lifestyle, and dietary interventions, as well as pharmaceutical agents, are inadequate for the regulation of cholesterol levels. Probiotic microorganisms have demonstrated the potential to lower cholesterol levels through various mechanisms, including the activity of bile salt hydrolase, production of enzyme-inhibiting compounds such as 3-hydroxy-3-methylglutaryl coenzyme A, and assimilation of cholesterol. In the present investigation a yeast culture designated as S-I, isolated from freshwater snail’s gut (Pila globosa), fulfilled probiotic attributes. The culture was found to be non-hemolytic and could tolerate a bile concentration up to 1.2%, pH 1.5–10; and temperature 42oC respectively. Additionally, 73.57% and 36.24% of S-I culture survived when exposed to the gastric environment for 90 and 180 min respectively, while 53% survived after 240 min incubation under the intestinal environment. The S-I culture could auto-aggregate (93.01%), as well as co-aggregate (77.89%) with gastrointestinal pathogens, an important property required for the probiotics to control the pathogens. The culture also inhibited C. albicans NCIM3557, E. coli NCIM3099, E. faecalis NCIM3040, S. aureus NCIM2408and P. aeruginosa NCIM2036 in-vitro. Other probiotic properties such as hydrophobicity (81%), bile salt hydrolase activity (86.30%), and tolerance to 8% NaCl (27.38%), as well as antibiotics, were found to be in favor of the S-I culture. Most importantly, S-I culture was found to assimilate 20.29% of cholesterol. Molecular characterization of this culture performed by 18S rRNA sequencing revealed that the S-I culture was Pichia kudriavzevii species with 97% similarity.

Distribution of freshwater Mollusca in Koothaippar wetland ecosystem Tiruchirappalli District Tamil Nadu

Freshwater Mollusca form an important animal group of the wetland ecosystems. The distribution and availability in terms of number of species needs scientific attention. Present study is an attempt to document the available Molluscan forms in Koothaippar wetlands of Tiruchirappalli District. This study was carried out between summer 2013 to post-monsoon 2017. Nine species were recorded and among them 6 species belong to Gastropoda representing 2 orders, 3 families, 3 genera while 3 species were bivalves representing 1 order, 1 family and 2 genera. Bellamya bengalensis, Lamellidens marginalis and Pila globosa were the predominantly present molluscan fauna and are distributed throughout the year. Five species of Molluscan fauna (Pila virens, Pila scutata, Bellamya dissimilis, Indoplanorbis exustus and Lamellidens corrianus) are less abundant and Parreysia favidens was found to be rare species of the ecosystem. These Molluscan forms, representing different families ranging from 34% of Ampullariidae, 33% of Unionoida, 22% of Viviparoidae and 11% of Planorbidae. Percent distribution of these shelled organisms indicate that they represent 3 orders viz., 56% of Architaenioglossa, 33% of Unionoida and 11% of Hygrophila.

Microstructure Analysis and Chemical and Mechanical Characterization of the Shells of Three Freshwater Snails.

The shells of freshwater snails are discarded as waste, which qualify as biological materials with prospective multiple uses. To substantiate this proposition, an attempt was made to elucidate the physical and chemical properties of the shells of three freshwater snails, namely, Bellamya bengalensis, Pila globosa, and Brotia costula. The shells were prepared for electron microscopy and assessment of the calcium carbonate content, apart from the Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), and nanoindentation studies. The results indicated that the calcium carbonate content (y) of the shells ranged between 87 and 96% of the total weight (x) and complied with a power regression equation: y = 0.801x1.016; R2 = 0.994; r = +0.998; P < 0.001. Observations through SEM depicted different snail species-specific arrangement patterns of calcium carbonate crystals in the diverse layers of shells. The XRD, FTIR, and EDS observations revealed the dominance of the aragonite form of the calcium carbonate crystal in the microstructures of each snail shell with the occurrence of different shell surface functional groups. The Brunauer–Emmett–Teller analysis elucidated the surface textures of shell dust taken from each snail species; in addition, the nanohardness properties indicate the shells as a tough biocomposite exoskeleton. Species-specific variations in the shell morphology, microstructure, and calcium carbonate content were prominent for the three freshwater snails considered for the study. Nonetheless, the physical and chemical properties substantiate that the shells of B. bengalensis, P. globosa, and B. costula qualify as biological materials for sustainable use in various fields including bioremediation, biocatalyst, biomedical applications, and a source of lime. Since the shells of the freshwater snails are discarded as aquaculture waste, subsequent use as a biological material will support the “waste made useful” paradigm in sustainability, both from ecological and economic perspectives.

Diversity of gastropods and bivalves in the mangrove ecosystem of Paradeep, east coast of India: a comparative study with other Indian mangrove ecosystems

ABSTRACTThe diversity of gastropods and bivalves from the mangrove ecosystem of Paradeep, east coast of India, was studied for the first time. The collected primary data and secondary data were compiled to prepare an updated checklist of mangrove-associated gastropods and bivalves of India. In total, 22 species were recorded during the field surveys of Paradeep mangroves of which 19 are gastropod and three are bivalves. The compilation of secondary data with the present primary data revealed the occurrence of 274 species of mangrove-associated gastropods and bivalves in India. The gastropods were represented by 182 species belonging to 50 families and bivalves were represented by 92 species belonging to 27 families. Neritidae, Muricidae, Nassariidae and Ellobiidae are observed to be the dominant gastropod families in the mangrove ecosystem of India and Teredinidae and Veneridae are the dominant families of Bivalvia. Maximum species diversity has been recorded from mangroves of Andaman and Nicobar Islands (91 species) and Maharashtra (83 species). Twenty-eight species of gastropods and bivalves inhabit the mangrove ecosystem of Odisha. The present study also reports the range extension of Monetaria moneta, Neritina smithii and Pila globosa in the mangrove ecosystem of Paradeep.

Record of Some Digeneans, Infecting Freshwater Fishes, Snails, and Amphibians in India, Using 28S Ribosomal DNA Marker

Eleven species of digenetic trematodes are recorded herein in an attempt to chart the trematode biodiversity in Kakraiya Lake of District Barabanki, U.P., infecting freshwater fishes, snails, and frogs. The species are Opisthorchis attuai and Isoparorchis hypselobagri from Wallago attu; Diplostomulum minutum from Heteropneustes fossilis; Buchephalopsis karvai from Xenentodon cancila; Cephalogonimus mukerjius, and Kaurma sp. from Pila globosa; Pseudodiplodiscoides murtyi from Bellamya bengalensis; Mesocoelium sociale from Duttaphrynus melanostictus; Diplodiscus amphichrus, Halipegus mehransis, and Halipegus barabankiensis n.sp. from Euphlyctis cyanophlyctis. Among the eight species considered as valid so far O. attuai, I. hypselobagri, M. sociale, B. karvai, P. murtyi, D. amphichrus, H. mehransis and C. mukherjius have been described well only at the adult stage, whereas the morphology of D. minutum, and Kaurma sp. at the metacercarial stage has been described, which further awaits to trace their life cycle. The present results show that H. barabankiensis represents distinct entities from a molecular and morphological point of views, which leads to the description of a new species. All these trematode species were subjected to morphological, morphometric, and molecular analysis. Partial nucleotide sequences of the 28S ribosomal gene were obtained from these trematode species and deposited in the GenBank. The phylogenetic reconstruction based on the 28S rRNA gene placed the studied species within the respective families, and their validity is discussed.

MOLLUSCAN DIVERSITY WITH PARTICULAR EMPHASIS TO SNAILS IN DISTRICT GAUTAM BUDH NAGAR (U.P.) INDIA

Present investigation reveals molluscan diversity of the 4 selected sites viz., Tilpata Karanbas, Manhcha, Latifpur and Atta Gujran in the vicinity of district Gautam Budh Nagar (U.P.). As many as 22 species of molluscs under 9 families were collected. There were 19 species of snails viz ., Bellamya bengalensis , B. dissimilis , B. crassa , Lymnaea ( Pseudosuccinea ) acuminata f. hians , L. luteola f. ovalis , L. acuminata f. patula , L . ( Radix ) auricularia , L . ( Lymnaea ) stagnalis , L . acuminata f. gracilior , Pila globosa , Indoplanorbis exustus , Gyraulus convexiculus , G. pankongensis , Planorbis planorbis var. tangitarensis , Hydrobioides nassa, Thiara ( Melanoides ) tuberculata , Thiara ( Thiara ) scabra, T. ( M .) trigrina and Brotia ( Antimelania ) costula under 6 families. The other molluscs were Parreysia ( Parreysia ) favidens , Corbicula striatella and Lamellidens marginalis . There has been a marked variation in the composition of molluscan species collected from different habitats.

Abundance-Biomass Comparison approach to assess the environmental stressors in Diyawannawa wetland in monsoonal and non-monsoonal seasons

Abundance-Biomass Comparison (ABC) approach is a graphical approach that compares the abundance and biomass of organisms in order to predict the environmental stress level of an ecosystem. The present study was conducted in selected sites located at non-rehabilitated and rehabilitated areas of the Diyawannawa wetland in Sri Lanka in the monsoonal and non-monsoonal seasons. The ABC was performed on the macrobenthic mollusk species collected from the study sites. Eight species of macrobenthic mollusks, namely, Bithynia tentaculata, Melanoides turbeculata, Melanoides turriculus, Thiara scabra, Lamellidens marginalis, Pila globosa, Gyraulus saigonensis and Lymnaea stagnalis were recorded during the study period. Based on Principal Component Analysis, B. tentaculata, and, P. globosa were identified as characteristic gastropod species that could be used to classify study sites in the rehabilitated and non-rehabilitated areas of this tropical wetland system. In the monsoonal season, overlapping cumulative percentage dominance of abundance and cumulative percentage dominance of biomass curves in sites A, B, and F indicated partially disturbed environmental conditions. The site C of the non-rehabilitated area, showed a typical undisturbed condition and the sites D and E of the rehabilitated area the cumulative percentage dominance of biomass curve was located above the abundance curve, indicating disturbed environmental conditions in these sites during monsoonal season. During the non-monsoonal season in all the sites except site F of the rehabilitated area, the cumulative percentage dominance of abundance curve was located above the biomass curve, indicating undisturbed environmental conditions in these sites. In the site F, the cumulative percentage dominance of abundance and the cumulative percentage dominance of biomass curves were crossing each other, indicating partially disturbed environmental conditions at this site. The values of the W statistic, which ranged from 0.004 to 0.374 in the non-monsoonal season and ranged from 0.1 to 0.2 in the monsoonal season, and pollution and water quality categorization by modified biotic index (MBI) were in agreement with the results of the ABC approach.

Phylogenetic Affinities of Indian Apple Snails: An Insight into the Tibetan Tectonic Terranes

Gastropods belong to a hyper-diverse clade of molluscs and encompass limpets, slugs and snails. Interestingly, gastropods have effectively colonized land, freshwaters and marine habitats. However, the relationships among and within its constituent taxa remained in flux for decades due to delimitation in their morphological and anatomical features and hence molecular approach has taken a lead. An understanding into the history of Tibetan tectonic terranes is attempted in this article to derive through the phylogeny of Pila. In our study, we have re-evaluated the relationships within Ampullariidae by collecting the species of Pila globosa and Pila virens (India) and analyzed them comparing with 18S rDNA sequences from public domain. Obtained sequences are evaluated through Maximum Likelihood method in MEGA v 5 which clearly established a single cluster for the three individual taxons namely P. globosa with high bootstrap support. Pila virens showed a paraphyletic cluster with Pila ovata. A low bootstrap value of a few species of Pila possibly inferred rapid speciation among them. The novel observation in the present study is that P. virens forming a secondary cluster with the species from Vietnam namely Pila polita, Pila conica and Pila ampullacea has authenticated that the south India and Vietnam are in the same latitude namely 9–20°N, supporting the paleomagnetic data which unravelled that India collided with Asia around 57 mya in the Coenozoic era, whereas ampullariids must have been in co-existence since the Cambrian Period indicating their long evolutionary affinity and zoo-geographical relationship.

In-Silico Construction of Phylogenetic Relationships Between Ampullariidae and Viviparidae Families (Gastropoda: Caenogastropoda) Using Partial Mitochondrial COI Sequences

Freshwater biota especially molluscs are more vulnerable because even the slightest change in the quality of their habitat possibly leads to their mortality. In addition, their importance is felt that particularly molluscs contribute toward carbon sequestering from the environment as atmospheric carbon gets deposited as carbonates in their shell which constitute 10% of their body mass. Hence, the molecular phylogenetic relationships of two families inhabiting freshwater streams viz., Ampullariidae and Viviparidae considering the genera dwelling in Indian subcontinent namely Pila globosa and Bellamya bengalensis using the partial nucleotide sequence of mitochondrial COI gene were of considerable importance in building conservational strategies. The phylogenetic analysis of ampullariid and viviparid species inferred that these two chosen families were paraphyletic and rooted on the genera of Cyclophoroidea and possibly with Saulea vitrea as the connecting link.

Assessment of Aquatic Faunal Diversity in the Ratargul Swamp Forest at Sylhet in Bangladesh

The study was conducted to asses the aquatic faunal diversity in the Ratargul Swamp Forest during the period from November 2014 to October 2015. For the systematic study of aquatic fauna, the quadrate method along with transect was used where 4 transects were selected in the swamp forest each with 5 stations based on topography and vegetation. A total of 24 species of aquatic fauna belonging to 18 families were identified during the period, which were crustaceans (7), molluscs (4), fishes (12) and annelid (1). Among them, fishes were the most dominant and abundant groups. The crustaceans, molluscs, fishes and annelid were shown different pattern of density and diversity within the Transects. The density of individuals in Ratargul Swamp Forest varied from station to station within a range of 8 to 40 Indm-². The lowest Simpson’s Index of Diversity was 2.76 in T-4, which was situated in the transitional area between forested land and relatively deep lake within the forest. Leptocarpus potamiscus, Nandus nandus, and Pila globosa were the dominant shrimp, fish and mollusc species in the T-4, respectively. The highest Simpson’s Index of Diversity was 3.89 in T-3, which was situated along the bank of a small channel within the forest. Nematopalaemon tenuipes, Puntius ticto, and Pila globosa were the dominant shrimp, fish and mollusc species in T-3, respectively.J. Environ. Sci. &amp; Natural Resources, 9(2): 51-64 2016