Pila Ovata Research Articles

Eco-toxicological assessment of heavy metals in the freshwater apple snail (Pila ovata) from selected markets in Benin metropolis, Nigeria

Eco-toxicological assessment of heavy metals in the freshwater apple snail (Pila ovata) from selected markets in Benin metropolis, Nigeria

Distributional Patterns of Gastropoda Upstream and Downstream of Bujagali Hydropower Project along the Upper Victoria Nile

To better understand the gastropod community dynamics of fresh water snails in the Upper Victoria Nile (UVN), the spatial and temporal abundance changes in gastropod assemblage were assessed biannually from April 2006 to April 2021 at three transects. Biannual abundances of gastropoda were obtained by a ponar grab to examine changes in their community structure in relation to Bujagali Hydropower Project (BHP). The gastropod community consisted of nine speciesbelonging to five families (Thiaridae, Viviparidae, Ampullariidae, Bithyniidae and Planorbidae). Pulmonate species registered five species <i>(Anisus natalensis, Gyraulus sp., Segmentorbis sp., Bulinus sp. and Biomphalaria chaonomphola)</i>. Two of the pulmonates <i>(Bulinus sp. and B. chaonomphala)</i> are schistomiasis vectors. The pulmonates <i>(A. natalensis, Gyraulus sp., Segmentorbis sp.)</i> were rare and intermittently occurred with abundances up to 47 ind.m-2. Four prosobranch species <i>(Gabbia humerosa, Pila ovata, Melanoides tuberculata and Bellamya unicolor)</i> were encountered. Of these prosobranchs, <i>P. ovata</i> was the rarest while <i>M. tuberculata</i> and <i>B. unicolor</i> were the commonest. The gastropod community in the UVN was characterised by prosobranchs-dominated abundance which over the 16-year monitoring period often registered peak densities of > 1000 ind.m2. The inter-site Percent Similarity Index (PSI) (94-100%) indicated a high degree of similarity of gastropod community across the sites.

Effect of anthropogenicity on the temporal diversity and abundance of macro-invertebrates in Calabar River, Okomita, Cross River State, Nigeria

The influence of anthropogenicity on the abundance and diversity of macro-invertebrates was investigated in Calabar River, Okomita, Cross River State for a period of 24 months (August, 2014-September, 2016) in six sampling stations. Bank root macro-invertebrates were collected by kick sampling while substrata macro-invertebrate samples were collected with a van-Veen grab. Seasonal variations in the values of the macro-invertebrates abundance were determined by pooling together the values for the wet and dry seasons. The difference in values in the six stations in each season was tested for significant difference (p < 0.05) while the pooled differences in the two seasons were tested using unpaired (independent) student’s t-test. Spcies diversity was estimated using the Shannon-Wiener index (H’), species richness (d) and evenness (J) of individual distribution among species. All macro-invertebrate groups had highest percentage abundance in the dry season months. Seasonal percentage abundance of insects was significantly different (p˂0.05). Higher seasonal abundance of the total macro-invertebrates was recorded in the dry season and the seasonal variation was significant (p˂0.05). Lower number of pollution intolerant species of macro-invertebrates (Sudanonautes africanus, Orectochilus orbisonorum, Dineutus discolour, Phaon iridipennis, Pila ovata, Natica flammulata and Eulima fischeri) recorded during the rainy season was an indication that the river was more perturbed during the rainy season as a result of influx of pollutants from refuse dumps, farmlands, Okomita Market, abattoir and mechanic workshop. The results of the PCA revealed that DO, hardness, alkalinity, magnesium and cadmium were the most important parameters influencing the abundance of macro-invertebrates in Calabar River, Okomita. Intermediate values and values less than one of Shannon-Weiner diversity index were observed, indicating that Calabar River, Okomita is moving from moderately polluted state to severely polluted condition.

The diversity of fresh water snail fauna in Kiri dam, Adamawa State, North Eastern Nigeria

Freshwater Snails are crucial in assessing the ecological status of water bodies, besides their economic, public and veterinary health importance. Hence, the need to study the occurrence, and diversity of freshwater snails in Kiri dam where there is paucity of such information becomes imperative. Accordingly, this study was carried out between December, 2016 and July, 2018. Snails were searched for in the five contact sites identified using long handle metal scoop nets in accordance with standard procedure. Snails recovered were examined for natural infections. Eleven (11) different fresh water snail species were encountered including Bulinus globosus, Bulinus truncatus, Biomphalaria pfeifferi, Lymnaea natalensis, Lanistes ovum, Lanistes varicus, Pila ovata, Melanoides maculata, Melanoides tuberculata, Bellamya unicolor and Gabiella tchadiensis of the eleven different snail species examined, only Bulinus globosus Bulinus truncatus and Biomphalaria pfeifferi shed schistosome cercariae. The other 8 species did not have any natural infections. The study revealed that Kiri Dam harbours diverse species of fresh water snails including those of public health importance. The presence of naturally infected snails indicates that the people engaging in various activities in the dam, are predisposed to infections harboured by these snails.

Diversity of digenean trematode larvae in snails from Lake Victoria, Kenya: First reports and bioindicative aspects

This study investigated the occurrence of digenean trematode larvae in snails from the Kenyan part of Lake Victoria. The survey included caenogastropod snails that have received less focus in parasitological studies in Africa: their trematodes are largely unknown. Out of 1145 snail specimens, 149 (13.0%) were infected with Digenea. The highest prevalence (P) was recorded in Melanoides tuberculata (64.5%), followed by Pila ovata (15.4%), Radix natalensis (9.5%), Bulinus ugandae (9.1%), Bellamya unicolor (8.9%), Biomphalaria pfeifferi (7.3%) and Biomphalaria sudanica (4.4%). Morphological and molecular analyses revealed 17 digenean species. Contrary to reports of low diversity of Digenea in caenogastropods, P. ovata harboured 8 species – at least twice as many as in each of the pulmonates. The following taxa are reported for the first time in the Lake Victoria region: Haplorchis pumilio, Thapariella prudhoei, Nudacotyle sp., Renicola sp. and Bolbophorus sp. An unknown cercaria belonging to the genus Haematoloechus is reported from P. ovata: a xiphidiocercaria possessing a long sword-shaped stylet (47–71 µm) which does not match any available literature records. From this study, H. pumilio from M. tuberculata (P = 69.4%), Fasciola gigantica from R. natalensis (P = 1.9%) and Bolbophorus sp. from Bu. ugandae (P = 4.6%) are species of veterinary or medical importance. Snails from the study site with little direct anthropogenic influence had the highest prevalence and diversity of digenean larvae, indicating that environmental conditions influence trematode occurrence.

Animal remains from the el-Hamra Christian complex in the el-Ga'ab Depression, West Dongola (Sudan)

The animal remains discussed in this paper come from three archaeological sites in the el‑Hamra Christian complex, excavated within the frame of the el‑Ga'ab Depression archaeological, ethnographical and ecological project. During two seasons in 2013/2014 and 2014/2015, a team directed by Yahia Fadl Tahir collected and examined a total of 89 mammal, five ostrich egg and 16 mollusk remains. The bone assemblage was divided into seven groups representing the most and least attractive parts of the carcass in terms of nutritional value. Identified species include sheep (Ovis aries) and goat (Capra hircus), while other animal remains include ostrich egg fragments and mollusk species: Pila ovata, Melanoides tuberculata and Lanistes carinatus. Similarities can be observed in livestock husbandry and subsistence patterns in the early Christian period in the Dongola region, where the economy depended on small mammals like sheep and goats to provide milk and meat.

Molecular phylogenetic location of a digenean larva isolated from the African ampullariid snail,<i> Pila ovata</i>, from Obazuwa in Edo State, Nigeria

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

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.

Community structure of molluscans in River Nile and its branches in Assiut governorate, Egypt

The present work aims to survey the benthic mollusc communities in River Nile and its branches in Assiut governorate, Egypt. Twenty-six species were recorded from the collecting sites during the period from March 2010 until March 2012. These species belong to fifteen families; eleven families of Gastropoda and four families of Bivalvia. The constant species in this survey were five species: Cleopatra bulimoides, Lanistes varicus, Lanistes carinatus, Melanoides tuberculata and Caelatura aegyptiaca. The accessory species were seventeen species: Mutela rostrata, Pila wernei, Sphaerium sp., Pila ovata, Bithynia connollyi, Lymnaea natalensis, Corbicula fluminalis, Theodoxus niloticus, Unio teretiusculus, Bellamya unicolor, Hydrobia aponensis, Pseudosuccinea columella, Valvata nilotica, Biomphalaria alexandrina, Bulinus truncates, Physa acuta and Gabbiella senaariensis and the accidental species were four species: Helisoma duryi, Succinea cleopatra, Corbicula fluminea and Gyraulus ehrenbergi. The species richness and diversity of molluscan community reach the maximum level in spring and summer months.

Evaluation of the acute toxicity of refined petroleum products against Pila ovata (Gastropoda: Ampullariidae) and Poecilia reticulata (Teleostei: Poeciliidae)

Static and static-renewal evaluation of the acute toxicity of three refined petroleum products — petrol, kerosene and diesel — against two freshwater animals, the mollusc Pila ovata and the fish Poecilia reticulata, was conducted in the laboratory. Petrol, kerosene and diesel were found to be moderately toxic to the test species, the 96h LC50 values being in the low ml l−1 range, but there was no consistent trend in the levels of toxicity recorded under the bioassay conditions. However, there was no significant difference (p > 0.05) in the toxicities of petrol, kerosene and diesel to individual test species in both the static and static-renewal bioassays. There were significant differences (p < 0.05) in toxicities of kerosene and diesel against Poecilia reticulata between both bioassays, by a factor of 7–8. Pila ovata was more susceptible to kerosene and diesel by the same factor as Poecilia reticulata was in the static bioassay. Differential toxicity of the refined petroleum products varied with the species tested, indicating that ranking of the order of toxicity of refined petroleum products cannot be generalised.

Bioaccumulation of heavy metals (Cu, Zn, Fe) in freshwater snail (&lt;i&gt;Pila ovata&lt;/i&gt;; Oliver 1804) from Ikpoba River of Southern Nigeria

In this study, the levels and bioaccumulation behaviors of copper, zinc and iron were determined in various body organs, viz: viscera and shell of freshwater snail, Pila ovata (Oliver 1804) collected from the upper and lower catchments of Ikpoba River, southern Nigeria. Heavy metal concentrations in snail and sediment samples were measured using an atomic absorption spectrophotometer. The mean concentrations (µgg -1 ) of Cu, Zn and Fe in the snail were estimated to be as follow, 4.56 – 6.71, 35.35 – 77.09 and 1257.21 – 1762.59, respectively. This study showed that under natural conditions, P. ovata is capable of bioaccumulating trace essential metals to elevated levels especially Fe and Zn up to 10 times higher than that found in the sediment. The accumulation pattern was strongly correlated with the amount of trace metals in the sediments. Bioaccumulation of Cu, Zn and Fe varied between the viscera and the shell. The viscera had the highest concentrations (µgg -1 ) of all metals than the shells; Cu, 2.03 – 5.8 (Viscera), 0.05 – 3.30 (Shell), Zn, 23.64 – 45.02 (Viscera), 1.87 – 15.15 (Shell) and Fe, 360.33 – 1526.59 (Viscera), 83.99 – 373.93 (Shell), which suggest that ingestion may be the main uptake route of these essential metals. A holistic biomonitoring approach is therefore proposed for these impacted areas to guide regulators in a direction of improvement. Keywords : heavy metals, bioaccumulation, freshwater snail, sediment, Ikpoba River Journal of Aquatic Sciences Vol. 21(1) 2006: 23-28

Microbiological and Chemical Characteristics of Meat and Shucking Liquid Wastes of Freshwater Snail (&lt;i&gt;Pila ovata&lt;/i&gt;)

Freshwater snails (Pila ovata) obtained from local harvesters were aseptically shucked and eviscerated to obtain the shucking liquid waste and meat, respectively. The two samples were assessed for microbiological quality and nutrient composition. The mean total viable counts (TVCs) of the shucking liquid (4.6 x 105 cfu ml–1) was significantly (p = 0.05) higher than that of the meat (2.8 x 103 cfu g–1) sample. There were low fungal counts (< 102cfu g–1 or ml–1) in both samples while the total coliform counts of the shucking liquid was 2.8 x 102 MPN 100ml–1. The most prevalent bacteria isolated from both samples included Streptococcus faecalis, Pseudomonas sp, Klebsiella sp, Escherichia coli and Salmonella sp while one mould Penicillium digitatum occurred in both. However, Vibrio parahaemolyticus and Bacillsus sp occurred only in the meat sample. The snail meat contained 75.00, 4.05 and 15.00mg/dl of protein, cholesterol and carbohydrate, respectively, while higher protein and lower carbohydrate levels were obtained in the shucking liquid. The calcium (14.60 mg/dl) and iron (148 &mu;g/dl) contents of the shucking liquid were higher than that of the meat sample. Key words: Freshwater snail, shucking liquid, microbiological,chemical, meat. Nigerian Food Journal Vol.22 2004: 1-6

The Bacteriological Profiles of Freshwater Snail (Pila Ovata) Subjected to Microcosms Simulating Local Storage Conditions

Freshwater snails (Pila ovata) were collected and subjected to four different storage microcosms: body of stagnant water (BSW), body of water changed intermittently (BWCI), hibernating condition (HC) and depuration process (DP). Samples from the different microcosms were analysed for microbiological profiles and dynamics. A significant (P= 0.05) increase (≈1.30 log c.f.u g−1) occurred in samples exposed to BSW. In contrast, unappreciable change was observed in samples subjected to BWCI. Much higher microbial populations were found in the intestines. Hibernation resulted in initial (i.e. within the first 3 months) microbial decrease but increase occurred thereafter. A more heterogeneous bacterial flora was observed at the initial stage of HC but anaerobic spore-formers dominated at the end of the HC. A significant (P= 0.05) microbial decrease occurred within 2 days of DP but thereafter remained virtually unchanged. The pH of samples exposed to BSW increased drastically. The observed microbial profiles have demonstrated the impacts of different microcosms on the potential risk or safety of freshwater snails to consumers. These therefore have underscored the importance of adequate processing/cooking prior to consumption of freshwater snails.

Freshwater snails on Mafia Island, Tanzania with special emphasis upon the genus Bulinus (Gastropoda: Planorbidae)

AbstractA survey of freshwater snails on Mafia Island has been conducted that mapped the distribution and, by using a timed searching strategy, documented the relative levels of abundance of species. Twenty‐five freshwater habitats around the island were surveyed; snails were found in 15 sites (60%). From the total number of snails collected (n=240), prosobranchs (59%) outnumbered pulmonates (41%). Potential intermediate hosts of urinary schistosomiasis were encountered and these Bulinus species were further characterized by analysis of six enzyme systems (GPI, PGM, MDH, HBDH, GDH &amp; AcP), by inspection of DNA sequence variation within mitochondrial cytochrome oxidase sub‐unit I (COI) and nuclear ribosomal internal transcribed spacer (ITS). Three species of Bulinus were found: a single B. africanus group taxon, B. nasutus, and two B. forskalii group taxa, B. forskalii and a species presently identified as Bulinus sp. in this paper. The genera Pila, Lanistes and Bulinus were widespread across the island and dominated the fauna. The remaining taxa were found in lower numbers and often only at single sites. Three prosobranchs: Lanistes purpureus, Pila ovata and Melanoides tuberculata were found. In addition to Bulinus, the pulmonates included a small discoidal planorbid (?)Ceratophallus and an ancylid (a freshwater limpet). The factors that shape the dispersal and distribution of molluscs on Mafia were considered. Water chemistry could be an important variable as both pH (mean 6.37±0.99 SD) and conductivity (mean μS=149±135 SD) were significantly different from similar habitats on neighbouring Zanzibar Island (P&lt;0.001). The Mafian fauna is clearly associated with that of mainland Africa and Madagascar.

Experimental control of the schistosome-transmitting snailBiomphalaria pfeifferiby the ampullariid snailPila ovata

Adults of the African ampullariid snail Pila ovata were examined for their ability to control laboratory populations of the pulmonate snail Biomphalaria pfeifferi, a widespread, intermediate host of the human pathogen Schistosoma mansoni in sub-Saharan Africa. In a 6-week experiment conducted in large (100 × 60 × 60 cm) outdoor tanks containing floating macrophytes (Nymphaea caerula) and initially set up with one adult ampullariid for every three adult pulmonates, the numbers of B. pfeifferi egg masses were always about half those in similar tanks without P. ovata. Although, by week 6, the numbers of B. pfeifferi in the control tanks (without ampullariids) had increased 5-fold, from an initial mean of 30 snails/tank, there was no significant increase in the numbers of B. pfeifferi in the experimental tanks (containing ampullariids). Results of experiments conducted in indoor glass aquaria indicated that adult P. ovata rapidly attacked egg masses or neonates (< 2.5 mm shell diameter) of B. pfeifferi but had no effect on the adults. The adult ampullariids also significantly decreased cover by floating macrophytes over a 6-week period compared with that in similar but ampullariid-free aquaria. This decrease in plant cover is relevant to biological control of the schistosome vectors as macrophytes serve as food, shelter and oviposition sites for pulmonate snails. The present results indicate the ability of P. ovata to inhibit multiplication of B. pfeifferi populations, at least under laboratory conditions, both directly, through predation, and indirectly, by competition for resources. Pila ovata may therefore prove useful in the biological control of medically important, pulmonate snails.

Experimental control of the schistosome-transmitting snail Biomphalaria pfeifferi by the ampullariid snail Pila ovata.

Adults of the African ampullariid snail Pila ovata were examined for their ability to control laboratory populations of the pulmonate snail Biomphalaria pfeifferi, a widespread, intermediate host of the human pathogen Schistosoma mansoni in sub-Saharan Africa. In a 6-week experiment conducted in large (100 x 60 x 60 cm) outdoor tanks containing floating macrophytes (Nymphaea caerula) and initially set up with one adult ampullariid for every three adult pulmonates, the numbers of B. pfeifferi egg masses were always about half those in similar tanks without P. ovata. Although, by week 6, the numbers of B. pfeifferi in the control tanks (without ampullariids) had increased 5-fold, from an initial mean of 30 snails/tank, there was no significant increase in the numbers of B. pfeifferi in the experimental tanks (containing ampullariids). Results of experiments conducted in indoor glass aquaria indicated that adult P. ovata rapidly attacked egg masses or neonates (< 2.5 mm shell diameter) of B. pfeifferi but had no effect on the adults. The adult ampullariids also significantly decreased cover by floating macrophytes over a 6-week period compared with that in similar but ampullariid-free aquaria. This decrease in plant cover is relevant to biological control of the schistosome vectors as macrophytes serve as food, shelter and oviposition sites for pulmonate snails. The present result indicate the ability of P. ovata to inhibit multiplication of B. pfeifferi populations, at least under laboratory conditions, both directly, through predation, and indirectly, by competition for resources. Pila ovata may therefore prove useful in the biological control of medically important, pulmonate snails.

Growth of Biomphalaria glabrata populations in the presence of the ampullariid snails Pila ovata, Lanistes carinatus and Marisa cornuarietis

Adults of three ampullariid species were examined for their ability to affect the population growth of Biomphalaria glabrata (M line strain) under laboratory conditions in which food (lettuce) was supplied ad libitum over an eleven week interval. Lanistes carinatus and Pila ovata were obtained from Kenya, and Marisa cornuarietis originated from the Dominican Republic. The presence of either 3 or 9 L. carinatus or 3 M. cornuarietis per 40 1 aquarium did not reduce the population size of B. glabrata below levels attained in control aquaria lacking ampullariids. The presence of 9 M. cornuarietis adults significantly reduced B. glabrata populations by week 10 of the experiment. Presence of 3 or 9 P. ovata per aquarium significantly reduced B. glabrata numbers below control levels starting at week four of the experiment. Aquaria with 9 P. ovata were observed to have fewer B. glabrata egg masses than control aquaria, but the number of egg masses observed was not significantly reduced in aquaria with 3 P. ovata or with 3 or 9 L. carinatus or M. cornuarietis. However, the presence of 3 or 9 adults of each ampullariid species resulted in a significant increase in the percentage of such egg masses that disappeared prior to expected hatching date and that were presumed to have been consumed. The results of this laboratory study suggest that further investigation of the role of ampullariids as biological control agents for pulmonate snails in sub-Saharan Africa should focus on P. ovata.

Studies on schistosomiasis in the Niger Delta: Schistosoma intercalatum in the urban city of Port Harcourt, Nigeria

Ova of S. intercalatum have been found in the urban city of Port Harcourt in the Niger Delta area of Nigeria, following examination of stool and urine samples from 1,709 persons (5-15 years of age) resident in various parts of the city. The ova occurred only in urine, with prevalence ranging from 1.0% to 9.8% with an overall prevalence of 5.7%. The intensity of the infection was low. Most infected individuals had counts of less than 500 ova in total bladder content. There was no significant difference in either the prevalence or intensity of the infection among the sexes (Male; prevalence 6.1%, intensity 527.3 vs Female; prevalence 5.4%, intensity 500.9). No case of infection with either S. haematobium or S. mansoni was encountered in the study. Malacological surveys in the gutters, creeks, streams and stagnant waterbodies within the city showed the presence of Lymnaea natalensis, Bulinus forskalii, Pila ovata, Melanoides tuberculata, Physa sp., Lanistes ovum and Segmentorbis sp. B. forskalii is indicated as the probable vector of S. intercalatum in the city. The growing problem of urban schistosomiasis in tropical Africa is discussed. Further studies on urban transmission and epidemiology of schistosomiasis in the Niger Delta area of Nigeria is also indicated.