Effect of water temperature and population density on the population dynamics of Schistosoma mansoni intermediate host snails
Abstract Background Mathematical models can be used to identify areas at risk of increased or new schistosomiasis transmission as a result of climate change. The results of these models can be very different when parameterised to different species of host snail, which have varying temperature prefer...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
BMC
2014-11-01
|
| Series: | Parasites & Vectors |
| Subjects: | |
| Online Access: | https://doi.org/10.1186/s13071-014-0503-9 |
| _version_ | 1797811709475291136 |
|---|---|
| author | Nicky McCreesh Moses Arinaitwe Wilber Arineitwe Edridah M Tukahebwa Mark Booth |
| author_facet | Nicky McCreesh Moses Arinaitwe Wilber Arineitwe Edridah M Tukahebwa Mark Booth |
| author_sort | Nicky McCreesh |
| collection | DOAJ |
| description | Abstract Background Mathematical models can be used to identify areas at risk of increased or new schistosomiasis transmission as a result of climate change. The results of these models can be very different when parameterised to different species of host snail, which have varying temperature preferences. Currently, the experimental data needed by these models are available for only a few species of snail. The choice of density-dependent functions can also affect model results, but the effects of increasing densities on Biomphalaria populations have only previously been investigated in artificial aquariums. Methods Laboratory experiments were conducted to estimate Biomphalaria sudanica mortality, fecundity and growth rates at ten different constant water temperatures, ranging from 13-32°C. Snail cages were used to determine the effects of snail densities on B. sudanica and B. stanleyi mortality and fecundity rates in semi-natural conditions in Lake Albert. Results B. sudanica survival and fecundity were highest at 20°C and 22°C respectively. Growth in shell diameter was estimated to be highest at 23°C in small and medium sized snails, but the relationship between temperature and growth was not clear. The fecundity of both B. sudanica and B. stanleyi decreased by 72-75% with a four-fold increase in population density. Increasing densities four-fold also doubled B. stanleyi mortality rates, but had no effect on the survival of B. sudanica. Conclusions The optimum temperature for fecundity was lower for B. sudanica than for previously studied species of Biomphalaria. In contrast to other Biomphalaria species, B. sudanica have a distinct peak temperature for survival, as opposed to a plateau of highly suitable temperatures. For both B. stanleyi and B. sudanica, fecundity decreased with increasing population densities. This means that snail populations may experience large fluctuations in numbers, even in the absence of any external factors such as seasonal temperature changes. Survival also decreased with increasing density for B. stanleyi, in contrast to B. sudanica and other studied Biomphalaria species where only fecundity has been shown to decrease. |
| first_indexed | 2024-03-13T07:27:44Z |
| format | Article |
| id | doaj.art-bd4eb35abad245d8a57289c386a43779 |
| institution | Directory Open Access Journal |
| issn | 1756-3305 |
| language | English |
| last_indexed | 2024-03-13T07:27:44Z |
| publishDate | 2014-11-01 |
| publisher | BMC |
| record_format | Article |
| series | Parasites & Vectors |
| spelling | doaj.art-bd4eb35abad245d8a57289c386a437792023-06-04T11:17:39ZengBMCParasites & Vectors1756-33052014-11-01711910.1186/s13071-014-0503-9Effect of water temperature and population density on the population dynamics of Schistosoma mansoni intermediate host snailsNicky McCreesh0Moses Arinaitwe1Wilber Arineitwe2Edridah M Tukahebwa3Mark Booth4School of Medicine, Pharmacy and Health, Durham UniversityVector Control Division, Ministry of HealthVector Control Division, Ministry of HealthVector Control Division, Ministry of HealthSchool of Medicine, Pharmacy and Health, Durham UniversityAbstract Background Mathematical models can be used to identify areas at risk of increased or new schistosomiasis transmission as a result of climate change. The results of these models can be very different when parameterised to different species of host snail, which have varying temperature preferences. Currently, the experimental data needed by these models are available for only a few species of snail. The choice of density-dependent functions can also affect model results, but the effects of increasing densities on Biomphalaria populations have only previously been investigated in artificial aquariums. Methods Laboratory experiments were conducted to estimate Biomphalaria sudanica mortality, fecundity and growth rates at ten different constant water temperatures, ranging from 13-32°C. Snail cages were used to determine the effects of snail densities on B. sudanica and B. stanleyi mortality and fecundity rates in semi-natural conditions in Lake Albert. Results B. sudanica survival and fecundity were highest at 20°C and 22°C respectively. Growth in shell diameter was estimated to be highest at 23°C in small and medium sized snails, but the relationship between temperature and growth was not clear. The fecundity of both B. sudanica and B. stanleyi decreased by 72-75% with a four-fold increase in population density. Increasing densities four-fold also doubled B. stanleyi mortality rates, but had no effect on the survival of B. sudanica. Conclusions The optimum temperature for fecundity was lower for B. sudanica than for previously studied species of Biomphalaria. In contrast to other Biomphalaria species, B. sudanica have a distinct peak temperature for survival, as opposed to a plateau of highly suitable temperatures. For both B. stanleyi and B. sudanica, fecundity decreased with increasing population densities. This means that snail populations may experience large fluctuations in numbers, even in the absence of any external factors such as seasonal temperature changes. Survival also decreased with increasing density for B. stanleyi, in contrast to B. sudanica and other studied Biomphalaria species where only fecundity has been shown to decrease.https://doi.org/10.1186/s13071-014-0503-9SchistosomiasisSchistosoma mansoniBiomphalariaMalacologyClimate changeEcology |
| spellingShingle | Nicky McCreesh Moses Arinaitwe Wilber Arineitwe Edridah M Tukahebwa Mark Booth Effect of water temperature and population density on the population dynamics of Schistosoma mansoni intermediate host snails Parasites & Vectors Schistosomiasis Schistosoma mansoni Biomphalaria Malacology Climate change Ecology |
| title | Effect of water temperature and population density on the population dynamics of Schistosoma mansoni intermediate host snails |
| title_full | Effect of water temperature and population density on the population dynamics of Schistosoma mansoni intermediate host snails |
| title_fullStr | Effect of water temperature and population density on the population dynamics of Schistosoma mansoni intermediate host snails |
| title_full_unstemmed | Effect of water temperature and population density on the population dynamics of Schistosoma mansoni intermediate host snails |
| title_short | Effect of water temperature and population density on the population dynamics of Schistosoma mansoni intermediate host snails |
| title_sort | effect of water temperature and population density on the population dynamics of schistosoma mansoni intermediate host snails |
| topic | Schistosomiasis Schistosoma mansoni Biomphalaria Malacology Climate change Ecology |
| url | https://doi.org/10.1186/s13071-014-0503-9 |
| work_keys_str_mv | AT nickymccreesh effectofwatertemperatureandpopulationdensityonthepopulationdynamicsofschistosomamansoniintermediatehostsnails AT mosesarinaitwe effectofwatertemperatureandpopulationdensityonthepopulationdynamicsofschistosomamansoniintermediatehostsnails AT wilberarineitwe effectofwatertemperatureandpopulationdensityonthepopulationdynamicsofschistosomamansoniintermediatehostsnails AT edridahmtukahebwa effectofwatertemperatureandpopulationdensityonthepopulationdynamicsofschistosomamansoniintermediatehostsnails AT markbooth effectofwatertemperatureandpopulationdensityonthepopulationdynamicsofschistosomamansoniintermediatehostsnails |