The gilled snails have a hard flat plate operculum attached on the rear of the foot. If needed, snails withdraw the head and foot into the shell and seal the opening with the operculum. Most gilled snails have separate sexes, while most lunged snails are hermaphroditic. Eggs are usually laid in gelatinous masses and attached to various submerged objects. Freshwater snails develop inside the egg mass and hatch as tiny snails with the slightly coiled shells. Ramshorn snails Planorbidae :. Pond snails Lymnaeidae :.
River snails Viviparidae :. Gallardo-Mayenco A, Toja J. Spatio-temporal distribution of Simuliids Diptera and associated environmental factors in two mediterranean basins of southern Spain.
The influence of physico-chemical and ecological factors on the distribution of freshwater snails in Manchok water intake in Kaduna state, Nigeria. Niger J Chem Res. Ofoezie IE. Distribution of freshwater snails in the man-made Oyan reservoir, Ogun state, Nigeria. Daldorph P, Thomas J. The effect of nutrient enrichment on a freshwater community dominated by macrophytes and molluscs and its relevance to snail control.
J Appl Biol. Macrophyte presence and growth form influence macroinvertebrate community structure. Aquat Bot. Relative influence of environmental variables on macroinvertebrate assemblages from an Iberian basin.
Population dynamics of freshwater snails Mollusca: Gastropoda at Qena governorate, upper Egypt. Egypt Acad J Biol Sci. Diversity, dynamic and ecology of freshwater snails related to environmental factors in urban and suburban streams in Douala-Cameroon central Africa. Aquat Ecol. Water quality standards white paper: chlorophyll- a criteria for public water supply lakes or reservoirs.
KDHE bureau of water. Topeka: KDHE; Freshwater snail distribution related to physico-chemical parameters and aquatic macrophytes in Giza and Kafr El-Shiekh governorates, Egypt. Sturrock RF. The schistosomes and their intermediate hosts. In: Mahmoud AAF, editor. London: Imperial College Press; Characterization of mosquito breeding sites in and in the vicinity of Tigray microdams. Ethiop J Health Sci.
Freshwater snail distribution related to environmental factors in Banco national park, an urban reserve in the Ivory Coast west Africa. Afr Zool. Recent urban growth and urinary schistosomiasis in Niamey, Niger. Trop Med Int Health. Distribution of freshwater snails in the river Niger basin in Mali with special reference to the intermediate hosts of schistosomes.
Download references. Our gratitude goes to laboratory assistants at the Department of Environmental Health Science and Technology, Jimma University, for support during field and laboratory activities. Finally, the surveys would not have been completed without the support of the local community who allowed us access to sampling sites. Box , Jimma, Ethiopia. Box , Hawassa, Ethiopia. You can also search for this author in PubMed Google Scholar.
AA helped to proof read the manuscript. MY was involved in field and laboratory activities. GMA participated in data analysis. All authors read and approved the final manuscript. Correspondence to Beekam Kebede Olkeba. Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material.
If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. Reprints and Permissions. Olkeba, B. Environmental and biotic factors affecting freshwater snail intermediate hosts in the Ethiopian Rift Valley region. Parasites Vectors 13, Download citation.
Received : 03 January Accepted : 01 June Published : 08 June Anyone you share the following link with will be able to read this content:. Sorry, a shareable link is not currently available for this article. Provided by the Springer Nature SharedIt content-sharing initiative. Skip to main content. Search all BMC articles Search. Download PDF. Abstract Background Knowledge of the distribution and habitat preference of freshwater snail intermediate hosts can provide information to initiate and set-up effective snail control programmes.
Methods Data on freshwater snails, physico-chemical water quality parameters, physical characteristics of habitat, predators and competitors, and anthropogenic activity variables were collected from sampling sites during the wet season of and Results It was found that Bulinus globosus Conclusions The findings reported herein suggest that integrated snail control strategies should be considered to control snails via protection of water bodies from disturbance by anthropogenic activities.
Background Snails are invertebrate animals of the class Gastropoda found in freshwater and other aquatic habitats around the world [ 1 ]. Methods Study area and location of sampling sites Data was collected from two spatially distinct agro-ecological zones, warm temperate rainy and tropical rainy climate zones, which are located in the Ethiopian Rift Valley Fig.
Full size image. Results Occurrence and abundance of freshwater snails A total of individual snails were collected from the sampling sites. Discussion This ecological investigation of gastropods focused on identifying environmental and biotic factors significantly affecting the occurrence and abundance of freshwater snail intermediate hosts in the Ethiopian Rift Valley.
Table 2 Descriptive statistics for the continuous predictor variables used to assess the occurrence and abundance of freshwater snail species in the Ethiopian Rift Valley Full size table.
Table 3 The frequency and percentages of the categorical predictor variables used to assess the occurrence and abundance freshwater snail species in the Ethiopian Rift Valley Full size table. Conclusions Generalized linear models indicated that physico-chemical water quality parameters, physical habitat characteristics and biotic factors were found to be the main variables determining the occurrence and abundance of snail species in the Ethiopian Rift Valley region.
Availability of data and materials Data supporting the conclusions of this article are included within the article and its additional files. Abbreviations NTU: nephelometric turbidity unit. References 1. Chapter Google Scholar 2.
PubMed Article Google Scholar 3. Google Scholar 4. PubMed Article Google Scholar 5. Google Scholar Article Google Scholar PubMed Article Google Scholar PubMed Google Scholar Book Google Scholar PubMed Central Google Scholar Chapter Google Scholar Article Google Scholar Download references. View author publications. Ethics declarations Ethics approval and consent to participate Not applicable.
Consent for publication Not applicable. Competing interests The authors declare that they have no competing interests. Additional information Publisher's Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Supplementary information. Additional file 1: Table S1. Output of the logistic regression model. Additional file 2: Table S2. Output of the zero-inflated Poisson regression model. About this article. Cite this article Olkeba, B. Copy to clipboard. Bogan, K. Brown, N. Burkhead, J. Cordeiro, J. Garner, P. Hartfield, D. Lepitzki, G. Mackie, E. Pip, T. Tarpley, J. They can be found in almost any freshwater habitat, including ponds, streams, lakes, and rivers Hamrsky.
Many freshwater snails are amphibious, so they can also be found in moist soil, or among plants found near bodies of water. North America has approximately species of freshwater snails Burch. Within Missouri, there are at least 50 species that come under 8 different families, and each family has multiple genera that come under it Wu et al.
This webpage gives examples of one species within each genus of the 8 different families. According to the Missouri Department of Conservation, freshwater snails originated in saltwater habitats approximately million years ago. Eventually, some of these snails adapted to freshwater habitats, and finally, to land. Aquatic snails with lungs also known as pulmonates are the ones that adapted to life on land. Interestingly, it is also hypothesized that some of the freshwater pulmonate snails seen today are descendents of land snails that readapted to living in freshwater habitats.
Freshwater snails are characterised as having a soft body, which is protected by a hard outer shell which is composed of calcium carbonate and other proteins. For most species, the shell is symmetrical, and twisted into a spiral, however, the specific characteristics of these shells, such as shape and color differ from species to species Burch. The reason why this shell is spiral is because most snails have coiled bodies, so the shell is coiled in order to accomodate the body.
It is also important to note that while externally snails might display bilateral symmetry, their internal organs are typically positioned in an asymmetrical manner Burch. However, some parts of the body, known as the head and the foot can be seen outside of the shell when the snail is active. Most snails have the ability to withdraw their head and foot back into their shell if they are threatened by predators, or during unfavourable climatic conditions Burch.
Snails have several orifices in the head and foot parts of their body. Other than the mouth, the side at which these orifices are located depends on the coiling of the snail. In dextral snails, the openings are on the right, whereas in sinistral snails, the openings are on the left Burch.
There are two main types of aquatic snails: those with gills, and those with lungs. Both of these types of aquatic snails have several species in Missouri Wu et al.
Gilled snails breathe underwater like a clam. A long tube-like structure draws water into the mantle, which is the tissue that connects the body to the shell. Here, the gills extract oxygen from the water, allowing the snail to breathe Missouri Department of Conservation.
These gilled snails also have a structure known as an operculum. This structure is attached to the foot, and seals the opening when the snail goes back into the shell Burch.
This structure protects the snail from predators and even prevents it from drying out in case it is out of water for extended periods of time.
Lunged snails, on the other hand, breathe through lung-like structures that are present within the mantle Missouri Department of Conservation.
Many of these lunged snails go above water to breathe, however, many also stay constantly underwater. Unlike gilled snails, lunged snails do not have an operculum Hamrsky. How snails reproduce is species dependent. Most gilled snails have separate sexes, while lunged snails are hermaphroditic, meaning that each individual can function as both male and female Missouri Department of conservation.
Eggs are generally laid in clutches, and in a large gelatinous mass. The snails develop fully within the egg, and hatch as tiny snails with shells which are slightly coiled Hamrsky. Freshwater snails are usually omnivores. They generally tend to eat algae, macrophytes and other dead plant and animal debris Hamrsky. The specific diets can differ from species to species. There are two major ways through which snails eat.
The first is through a mouthpiece known as a radula, which has many small teeth like structures in it. During this process, snails scrape against rocks, or the ground, and collect any algae, and food attached to it. This process is known as scraping or grazing Hamrsky.
The other way through which snails eat is through ciliary or filter feeding. This occurs when the snail moves its cilia, causing it to draw in water, along with other nutrients and microorganisms. The water is filtered by the cilia, allowing the snail to consume the nutrients and microorganisms.
This means that they intake water with nutrients, and microorganisms, and then filter the water out, consuming the nutrients and microorganisms.
According to the Missouri Department of Conservation, freshwater snails play an intermediate role in food chains. They consume plants and animal debris, and later become food for larger animals such as fish and birds.
Several fish have adapted specialized throat teeth for cracking through snail shells. Many freshwater snails are intermediate hosts for parasitic flatworms known as trematodes Missouri Department of Conservation. These worms causes a disease known as schistosomiasis commonly known as snail fever in warm-blooded animals. According to the World Health Organization, people get infected by these parasites when larval forms of it penetrate the skin when there is contact with infested water.
These larval parasites are released into water by freshwater snails.
0コメント