scholarly journals Toxicity of Metals to a Freshwater Snail,Melanoides tuberculata

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
M. Shuhaimi-Othman ◽  
R. Nur-Amalina ◽  
Y. Nadzifah

Adult freshwater snailsMelanoides tuberculata(Gastropod, Thiaridae) were exposed for a four-day period in laboratory conditions to a range of copper (Cu), cadmium (Cd), zinc (Zn), lead (Pb), nickel (Ni), iron (Fe), aluminium (Al), and manganese (Mn) concentrations. Mortality was assessed and median lethal times (LT50) and concentrations (LC50) were calculated. LT50and LC50increased with the decrease in mean exposure concentrations and times, respectively, for all metals. The LC50values for the 96-hour exposures to Cu, Cd, Zn, Pb, Ni, Fe, Al, and Mn were 0.14, 1.49, 3.90, 6.82, 8.46, 8.49, 68.23, and 45.59 mg L−1, respectively. Cu was the most toxic metal toM. tuberculata, followed by Cd, Zn, Pb, Ni, Fe, Mn, and Al (Cu > Cd > Zn > Pb > Ni > Fe > Mn > Al). Metals bioconcentration inM. tuberculataincreases with exposure to increasing concentrations and Cu has the highest accumulation (concentration factor) in the soft tissues. A comparison of LC50values for metals for this species with those for other freshwater gastropods reveals thatM. tuberculatais equally sensitive to metals.

2011 ◽  
Vol 7 (9) ◽  
pp. 9-14 ◽  
Author(s):  
Ramesh Devkota ◽  
Prem Bahadur Budha ◽  
Ranjana Gupta

Because Nepal has been virtually unexplored with respect to its trematode fauna, we sampled freshwater snails from grazing swamps, lakes, rivers, swamp forests, and temporary ponds in the Chitwan district of central Nepal between July and October 2008. Altogether we screened 1,448 individuals of nine freshwater snail species (Bellamya bengalensis, Gabbia orcula, Gyraulus euphraticus, Indoplanorbis exustus, Lymnaea luteola, Melanoides tuberculata, Pila globosa, Thiara granifera and Thiara lineata) for shedding cercariae. A total of 4.3% (N=62) infected snails were found, distributed among the snail species as follows (B. bengalensis - 1, G. orcula - 11, G. euphraticus - 8, I. exustus - 39, L. luteola - 2 and T. granifera - 1). Collectively, six morphologically distinguishable types of trematode cercariae were found: amphistomes, brevifurcate-apharyngeate (likely mammalian schistosomes), clinostome, gymnocephalus (likely fasciolid), longifurcate-pharyngeate and xiphidiocercaria. I. exustus had the highest prevalence of trematode infection, and harbored all the noted cercarial types except gymnocephalus cercariae. One double infection (xiphidiocercaria and longifurcate-pharyngeate cercaria) was found in this snail. Amphistome cercariae were common in G. euphraticus, G. orcula, and I. exustus. The highest prevalence of infection (38.3%) was recorded among snails collected from temporary ponds.DOI: http://dx.doi.org/10.3126/hjs.v7i9.2183 Himalayan Journal of Sciences Vol.7 Issue 9 2011 pp.9-14


2020 ◽  
Vol 32 ◽  
Author(s):  
Denise Tieme Okumura ◽  
Odete Rocha

Abstract: Aim In the present study has analyzed several aspects of the life history traits of Melanoides tuberculata, an exotic species, under laboratory conditions, and its response to some stressors has also been applied. Methods Sensitivity to two toxic substances was tested. The mollusks were collected and cultured in the laboratory under controlled conditions of temperature of 25 ± 1 °C and ad libitum food regime. Growth rates and biomass were experimentally obtained and the individual growth curve obtained. Results The experiment lasted 287 days and the maximum shell lengths registered was 11.67 mm. The growth curve indicated a rate of 3.98 year-1 and a maximum theoretical length of 10.61 mm. The mean post-embrionary development time until first reproduction was 275 days and the size of the primipara was 10.13 mm. An accelerated growth of juveniles was observed with fast increase in the shell length until sexual maturity, but growth rate decreased afterwards as more energy was devoted to reproduction. Under the combination of 25 °C and fed on alternate days, M. tuberculata had a slow growth and a long-life expectancy under laboratory conditions. The tolerance of this mollusk to temperature as a stressor ranged between 16 °C and 37 °C, being the optimum temperature situated between 29 °C and 34 °C. The LC(I)50-24h for reference substances were: 0.70 g L-1 for KCl and 9.05 g L-1 for NaCl. Conclusion Based on these results, we can conclude that M. tuberculata is a species tolerant to temperature and salinity, what partially explains to accordance to its wide and rapid dispersion throughout tropical waters.


2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Mohammad Shuhaimi-Othman ◽  
Nadzifah Yakub ◽  
Nur-Amalina Ramle ◽  
Ahmad Abas

Adults of freshwater ostracodStenocypris major(Crustacea, Candonidae) were exposed for a four-day period in laboratory conditions to a range of copper (Cu), cadmium (Cd), zinc (Zn), lead (Pb), nickel (Ni), iron (Fe), aluminium (Al), and manganese (Mn) concentrations. Mortality was assessed, and median lethal times (LT50) and concentrations (LC50) were calculated. LT50and LC50increased with the decrease in mean exposure concentrations and times, respectively, for all metals. LC50s for 96 hours for Cu, Cd, Zn, Pb, Ni, Fe, Al, and Mn were 25.2, 13.1, 1189.8, 526.2, 19743.7, 278.9, 3101.9, and 510.2 μg/L, respectively. Metals bioconcentration inS. majorincreases with exposure to increasing concentrations, and Cd was the most toxic toS. major, followed by Cu, Fe, Mn, Pb, Zn, Al, and Ni (Cd>Cu>Fe>Mn>Pb>Zn>Al>Ni). Comparison of LC50values for metals for this species with those for other freshwater crustacean reveals thatS. majoris equally or more sensitive to metals than most other tested crustacean.


1983 ◽  
Vol 78 (3) ◽  
pp. 335-341 ◽  
Author(s):  
Frederico Simões Barbosa ◽  
Dirceu P. Pereira da Costa ◽  
Francisco Arruda

For the development of laboratory experiments on the competitive interacitons between freshwater snail populations, special snail rooms were set up in the main building of the Research Center "Aggeu Magalhães". In the current paper, the first of a series on this subject, the general methodology of the laboratory work is described in detail. Using indoor cement channels in which a uniform seminatural environment was created, interactions of freshwater snail populations can be studied with minimal interference of the usual variables. Controlled indoor environmental techniques, as described in the current paper, may also be utilized in different types of experiments in malacology, and represent a substantial technical advance in malacological work.


Paleobiology ◽  
2020 ◽  
Vol 46 (3) ◽  
pp. 356-378
Author(s):  
Kristopher M. Kusnerik ◽  
Guy H. Means ◽  
Roger W. Portell ◽  
Mark Brenner ◽  
Quan Hua ◽  
...  

AbstractTaphonomic processes are informative about the magnitude and timing of paleoecological changes but remain poorly understood with respect to freshwater invertebrates in spring-fed rivers and streams. We compared taphonomic alteration among freshwater gastropods in live, dead (surficial shell accumulations), and fossil (late Pleistocene–early Holocene in situ sediments) assemblages from two Florida spring-fed systems, the Wakulla and Silver/Ocklawaha Rivers. We assessed taphonomy of two gastropod species: the native Elimia floridensis (n = 2504) and introduced Melanoides tuberculata (n = 168). We quantified seven taphonomic attributes (aperture condition, color, fragmentation, abrasion, juvenile spire condition, dissolution, and exterior luster) and combined those attributes into a total taphonomic score (TT). Fossil E. floridensis specimens exhibited the greatest degradation (highest TT scores), whereas live specimens of both species were least degraded. Specimens of E. floridensis from death assemblages were less altered than fossil specimens of the same species. Within death assemblages, specimens of M. tuberculata were significantly less altered than specimens of E. floridensis, but highly degraded specimens dominated in both species. Radiocarbon dates on fossils clustered between 9792 and 7087 cal BP, whereas death assemblage ages ranged from 10,692 to 1173 cal BP. Possible explanations for the observed taphonomic patterns include: (1) rapid taphonomic shell alteration, (2) prolonged near-surface exposure to moderate alteration rates, and/or (3) introduction of reworked fossil shells into surficial assemblages. Combined radiocarbon dates and taphonomic analyses suggest that all these processes may have played a role in death assemblage formation. In these fluvial settings, shell accumulations develop as a complex mixture of specimens derived from multiple sources and characterized by multimillennial time-averaging. These findings suggest that, when available, fossil assemblages may be more appropriate than death assemblages for assessing preindustrial faunal associations and recent anthropogenic changes in freshwater ecosystems.


Author(s):  
N. E. Yuldashev ◽  

The article presents the results of studying the new and affordable means for freshwater snail control. It was found that mineral fertilizers – ammonium sulfate at a concentration of 0.05–0.2%, and potassium chloride at a concentration of 0.2–0.3% cause the death of snails of the genera Lymnae and Planorbis in 24–72 hours after application. Hydrogen peroxide at a concentration of 1:40000 and potassium permanganate at a concentration of 1:400000 also kill snails within 24–48 hours. Commonly available products also have pronounced molluscicidal action: table salt (NaCl) and baking soda (NaHCO3) at concentrations of 0.3–0.5%. Changing the pH in the habitat of snails, i.e. waters in snail biotopes, towards acidity (3.8–6.2) and alkalinity (8.0–8.4) also result in the death of snails, and the optimal environment is with pH = 7.8. These means are safe for animals and the environment, as evidenced by the results of experiments carried out on sheep, which were administered with molluscicide solutions forcibly using a probe in an amount of 1.5 liters and by free drinking for 3 days.


2021 ◽  
Author(s):  
Sydney Stork ◽  
Joseph Jalinsky ◽  
Maurine Neiman

Once-useful traits that no longer contribute to fitness tend to decay over time. We address whether the expression of mating-related traits that increase the fitness of sexually reproducing individuals but are likely less useful or even costly to asexual counterparts seems to exhibit decay in the latter. Potamopyrgus antipodarum is a New Zealand freshwater snail characterized by repeated transitions from sexual to asexual reproduction. The frequent coexistence of sexual and asexual lineages makes P. antipodarum an excellent model for the study of mating-related trait loss. We used a mating choice assay including sexual and asexual P. antipodarum females and conspecific (presumed better choice) vs. heterospecific (presumed worse choice) males to evaluate the loss of behavioural traits related to sexual reproduction. We found that sexual females engaged in mating behaviours with conspecific mating partners more frequently and for a greater duration than with heterospecific mating partners, while asexual females seemed to lack the ability to make a choice. These results suggest that selection acting to maintain mate choice in asexual P. antipodarum is weak or ineffective relative to sexual females and that asexual reproduction likely contributes to the evolutionary decay of behavioural traits in this system.


2020 ◽  
Vol 19 (3B) ◽  
Author(s):  
Soenarwan Hery Poerwanto ◽  
Dian Antika Kusuma Dewi ◽  
Giyantolin Giyantolin

The life cycle of Digenea subclass trematodes  that mostly involves snails as intermediate host in the larval stage in the form of sporocysts, redia and cercariae. This study aims to determine the species of freshwater snails, populations and stages of trematoda larvae that infect freshwater snails in the paddy fields and also the factors that influence the population of trematoda larvae. This research method uses purposive random sampling. Snails were collected from paddy fields in Sleman Regency, Yogyakarta City and Bantul Regency, Special Region of Yogyakarta. Snails and Trematodes larvae were identified based on morphological characters with a microscope. The results showed that the species of freshwater snail as  an inang antara  of Trematode was Lymnaea sp. (96.9%), Pomacea canaliculata (2.6%), and Brotia sp. (0.5%). The total population of trematoda larvae in freshwater snails was 4329 individuals with the largest population in Sleman Regency (2784 individuals). Trematode larval stages found were sporocysts (4.8%), redia (8.3%), Leptocercous type cercariae (35.2%), and Furcocercous type cercariae (51.7%). The most trematode larvae found in  fresh water snail was  Furcocercous type cercariae. Factor affecting trematode larvae population are the species and abundance of freshwater snail. 


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