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Melanoides tuberculata (Müller, 1774) food preference when grazing on
Vaucheria geminata, Melosira varians and Oscillatoria found in Volusia Blue Spring
Shantinique “Kionna” GravesMentor: Dr. Work
http://ts3.mm.bing.net/th?id=H.4929270748479614&w=266&h=181&c=7&rs=1&pid=1.7
Exotic/Invasive species• What is an exotic species?
– Any plant or animal species that has been introduced into an area where they do not naturally occur. Termed: Non-native ("U.S. Fish & Wildlife Service.")
– Invasions of ecosystems by exotic species are increasing, especially in aquatic ecosystems (Byers, 2000)
http://www.aquaesfera.org/atlas/d/5686-4/Melanoides-tuberculata-12.jpg
Exotic/Invasive species• Impact
– Predation – exotic crab prey on native snail (Edgell and Rochette, 2008)
– Competition – invasive snail outcompeted native, aiding in invasion (Byers, 2000)
– Indirect effects – looked at all invasive species as a whole, where you can get total eradication, tolerance, consideration of being a “new” species and overall enrichment to ecosystems: helpful or harmful (Walther, Gian-Reto, et al., 2009) • Nutrient recycling• Selective grazing
Melanoides tuberculata
• Phylum: Mollusca– Class: Gastropoda
• Family: Thiaridae– Genus: Melanoides
• Common names: Red-rimmed melania or Malaysian trumpet snail (aquarium trade)
• Freshwater snail that burrows• Colonizing behavior (mostly asexual and
ovoviviparous) + longevity = successful invasion
https://taxo4254.wikispaces.com/file/view/Features%20of%20snail.jpg/530277828/501x271/Features%20of%20snail.jpg
https://taxo4254.wikispaces.com/file/view/Anatomy%20of%20combined.jpg/529987378/510x331/Anatomy%20of%20combined.jpg
Occurrences• M. tuberculata is originally a native to tropical and subtropical regions
of Africa and Asia (Wingard et al. 2008; Clench, 1969; Neck, 1985). They became exotic through release from the aquarium trade, in which they were imported for in the early 1930’s.
Black = present, Blue = widespread, Red = localized, Green = distributed within a country, Yellow = few reports of being occasionally seenhttps://taxo4254.wikispaces.com/file/view/Global%20distribution%20of%20MT.jpg/530325582/616x332/Global%20distribution%20of%20MT.jpg
http://nas2.er.usgs.gov/viewer/GetStaticMap.aspx?region=us&width=700&height=450&layer=na%20gl%20bnds%20sts%20rivers%20shuc6%20shuc8%20snativehuc%20maptitle%20logo%20legend%20copy&maptitle=Melanoides%20tuberculata%20&speciesid=1037
It was first spotted in the United States in Arizona in the 1950's (Murray, 1971; Dundee, 1974). They are very successful in Florida and Texas (Benson and Neilson, 2014).
Purpose
• Impact of exotic species– Predation– Competition– Indirect effects
• Nutrient recycling• Selective grazing
Volusia Blue Spring State Park• M. tuberculata likes to live
in areas humans inhabit• Prefer areas that have
slow or stagnant flow• Cause for concern:
– Exotic– Host for parasitic flukes
(liver and lung)– Effect on the biological
landscape (ecosystem)
Volusia Blue Spring algal bloomshttps://encrypted-tbn0.gstatic.com/images?
q=tbn:ANd9GcTjuInHokHTHDY20q-GJoOS9i7xSWjIcPrdfOBB2sqigpHjreT8LA
https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcRqCBXiSZhvR4XbMPukyH6n2hWo4eDk7weRkBvRlvIYBHAJaFML
http://www.landcareresearch.co.nz/__data/assets/image/0019/62272/melosira3.jpg
https://microscopesandmonsters.files.wordpress.com/2013/09/browney_melosira_1.jpg
http://pages.vassar.edu/viva/files/2013/08/IMG_6156.jpg
http://oceandatacenter.ucsc.edu/PhytoGallery/images_AM/Freshwater/oscillatoria3.jpg
Grazing• It is an aquatic herbivorous snail that feeds
on benthic and epiphytic algae– Mainly eat algae, such as microalgae
(diatoms)– Can also eat detritus and organic particles that
are deposited on the sediments (detritivore) (Subda Rao and Mitra, 1982)
– Generalist?
Hypothesis• Does M. tuberculata have a
food preference for one of the dominant algae found in Volusia Blue Springs State Park?
• We hypothesized that M. tuberculata would have a food preference for Vaucheria geminata.
Methods
Statistical analysis• One-way ANOVA with Tukey multiple
comparisons to compare algal weight loss between treatments
Results• M. tuberculata had a food preference
– for Vaucheria geminata
Figure 1. Overall average algae wet weight loss after the experiment Snails: p < 0.0001, Algae: p < 0.0001, Interaction: p =0.033
Does preference change with type of algae present?
• We wanted to know if placement mattered among the algae
• With and without snails
Figure 2. Vaucheria algal wet weights compared to Melosira and Oscillatoria with and without snails.
P = 0.541 Not Statistically Significant
Figure 3. Melosira algal wet weights compared to Vaucheria and Oscillatoria with and without snails
P < 0.0001 Statistically Significant
Figure 4. Oscillatoria algal wet weights compared to Vaucheria and Melosira with and without snails
P < 0.24 Not Statistically Significant
Discussion• Does M. tuberculata have a food
preference for one of the algae found in Volusia Blue Springs State Park?– Supported
• Interesting finding:– Placement in treatments was important
Discussion Cont.• Placement was important
– Vaucheria was the most eaten and placement did not matter
– Oscillatoria was the least eaten and placement did not matter
– However, placement mattered when it came to Melosira• More Melosira was consumed when
Oscillatoria was present than Vaucheria
Future research• Do they eat other types of algae?• Growth on different types of algae• Patterns of algal growth and proximity
of Melanoides to different taxa• Competition?• Larger sample size
Acknowledgements• Stetson Biology Department• Dr. Work• Friends & Family• Blue Spring State Park
Work cited
Benson, A.J., and M.E. Neilson. (2014) Melanoides tuberculata. USGS Nonindigenous Aquatic Spesies Database, Gainesville, Fl. http://nas.er.usgs.gov/queries/FactSheet.aspx?SpeciesID=1037 Revision Date: 2/28/2013 (Accessed 14 March 2014)
Byers, J.E. (2000) Competition between Two Estuarine Snails: Implications for Invasions of Exotic Species. Ecology 81(5): 1225-1239
Clench, W.J. (1969) Melanoides tuberculata (Muller) in Florida. Nautilus 83: 72Dundee, D.S., (1974) Catalog of introduced mollusks of eastern North America (north of Mexico). Sterkiana 55: 1-37Edgell, T.C. and Rochette, R. (2008) Differential snail predation by an exotic crab and the geography of shell-claw covariance in
the Northwest Atlantic. Evolution 62(5): 1216-1228Murray, H.D., (1971) The introduction and spread of thiarids in the Unites States. The Biologist 53(3): 133-135Neck, R.W. (1985) Melanoides tuberculata in extreme southern Texas. Texas Conchologist 21(4): 150-152"U.S. Fish & Wildlife Service." FAQs. N.p., n.d. Web. 06 Apr. 2015.Walther, Gian-Reto, et al. (2009) "Alien species in a warmer world: risks and opportunities." Trends in ecology & evolution
24(12): 686-693.Wingard, G.L., Murray, J.B., Schill, W.B., Phillips, E.C. (2008) "Red-Rimmed Melania (Melanoides tuberculatus) - A Snail in
Biscayne National Park, Florida - Harmful Invader or Just a Nuisance?" USGS United States Geological Survey http://pubs.usgs.gov/fs/2008/3006/pdf/fs2008-3006.pdf (Accessed 13 February 2014)
Questions?