L. irrorata is an essential part of the salt marsh ecosystem. This is displayed in its strong relationship with Sporobolus alterniflorus, also known as Spartina alterniflora, a common vegetation found in abundance in Salt Marshes.[1]
Description
editL. irrorata is extremely temperature tolerant. The snail retracts its foot into it's shell when experiencing thermal stress which allows them to avoid water loss by evaporation and survive in high temperatures. [2]
Distribution
editSpatial distributions of L. irrorata in salt marshes likely depend on predation pressures and vary with geography.[1] It is possible that S. alterniflorus stem density plays a role in the local distribution of L. irrorata.[3]
Ecology
editHabitat
editL. irrorata can usually be found on the stock of S. alterniflorus and in some Salt Marshes on dead, fallen leaves of S. alterniflorus.[4] L. irrorata has also been observed to inhabit Spartina cynosuroides.[5]There were no significant differences in snail population density between S. alterniflorus and S. cynosuroides.[5] However, S. cynosuroides was observed to be a safer habitat due to it's superior height.[5] The shell size of the snail has been found to increase with decreasing elevation in Virginia salt marshes but the exact opposite has been found in South Carolina and Florida salt marshes.[1]
Feeding Habits
editThe diet of L. irrorata also consists of algal mats on the salt marsh floor, dead S. alterniflorus, live S. alterniflorus, marsh sediment.[6]L. irrorata is capable of having a strong top-down control of S. alterniflorus production by the grazing of live S. alterniflorus.[7]
Predation
editPredators of L. irrorata include Blue crabs, diamondback terrapins, clapper rail, and northern raccoons.[8] Predator cues for L. irrorata can be water related as well as airborne.[9] It is likely that chemicals in the incoming tide cue the snails to climb S. alterniflorus. It is also possible that blue crabs give off some compound which is aerosolized and detected by L. irrorata.[9] L. irrorata responds quickest to chemicals released when the shells of other snails are broken.[10]
In order to avoid predation, L. irrorata has the ability increase the thickness of their shell ridge which in turn decreases the size of their aperture opening.[1] This makes it difficult for predators to remove them from their shell. This is an essential function to have as Blue Crabs are commonly seen chipping away at the shell ridge in order to feed on the snail.[1]
Another method L. irrorata uses to avoid predation is vertical climbing of the grass Sporobolus alterniflorus. The snails climb up the grass during high tide to avoid predation and descend during low tide to feed. This is a very effective defense against predators.[11]
Impacts of the Deepwater Horizon Oil Spill
edit
The Deepwater Horizon Oil Spill had major impacts on the productivity, population density, and growth of L. irrorata in salt marshes along the Gulf of Mexico and southeastern United States. Snail densities were reduced by 80-90% on the oil covered salt marsh edges and 50% in the marsh interior.[8] The major loss of adult snails resulted in a reduced mean snail size in salt marshes. It was originally projected that it would take about 3-5 years for the L. irrorata population density to recover from the oil spill[8]. However, snail populations still have not made a full recovery nine years after the oil spill. It is now projected that it could take one to two decades for L. irrorata populations to fully recover at heavily oiled sites.[12]
References
edit- ^ a b c d e Rietl, Anthony J.; Sorrentino, Madelyn G.; Roberts, Brian J. (2018-06). "Spatial distribution and morphological responses to predation in the salt marsh periwinkle". Ecosphere. 9 (6): e02316. doi:10.1002/ecs2.2316.
{{cite journal}}: Check date values in:|date=(help) - ^ Iacarella, Josephine C.; Helmuth, Brian (2011-12). "Experiencing the salt marsh environment through the foot of Littoraria irrorata: Behavioral responses to thermal and desiccation stresses". Journal of Experimental Marine Biology and Ecology. 409 (1–2): 143–153. doi:10.1016/j.jembe.2011.08.011.
{{cite journal}}: Check date values in:|date=(help) - ^ Kiehn, Whitney M.; Morris, James T. (2009-09). "Relationships betweenSpartina alterniflora andLittoraria irrorata in a South Carolina salt marsh". Wetlands. 29 (3): 818–825. doi:10.1672/08-178.1. ISSN 0277-5212.
{{cite journal}}: Check date values in:|date=(help) - ^ Crist, R. Wyle; Banta, William C. (1983-01-01). "Distribution of the Marsh Periwinkle Littorina irrorata (Say) in a Virginia Salt Marsh". Gulf Research Reports. 7. doi:10.18785/grr.0703.04. ISSN 0072-9027.
- ^ a b c Failon, Caroline Mackenzie; Wittyngham, Serina Sebilian; Johnson, David Samuel (2020-10). "Ecological Associations of Littoraria irrorata with Spartina cynosuroides and Spartina alterniflora". Wetlands. 40 (5): 1317–1325. doi:10.1007/s13157-020-01306-4. ISSN 0277-5212.
{{cite journal}}: Check date values in:|date=(help) - ^ Alexander, Steve (1979-01-01). "Diet of the Periwinkle Littorina irrorata in a Louisiana Salt Marsh". Gulf and Caribbean Research. 6 (3): 293–295. doi:10.18785/grr.0603.11. ISSN 1528-0470.
- ^ Silliman, Brian R.; Zieman, Jay C. (2001-10). "Top-Down Control of Spartina alterniflora Production by Periwinkle Grazing in a Virginia Salt Marsh". Ecology. 82 (10): 2830. doi:10.2307/2679964.
{{cite journal}}: Check date values in:|date=(help) - ^ a b c Zengel, Scott; Montague, Clay L.; Pennings, Steven C.; Powers, Sean P.; Steinhoff, Marla; Fricano, Gail; Schlemme, Claire; Zhang, Mengni; Oehrig, Jacob; Nixon, Zachary; Rouhani, Shahrokh (2016-01-19). "Impacts of the Deepwater Horizon Oil Spill on Salt Marsh Periwinkles ( Littoraria irrorata )". Environmental Science & Technology. 50 (2): 643–652. doi:10.1021/acs.est.5b04371. ISSN 0013-936X.
- ^ a b Carroll, John M.; Church, Morgan B.; Finelli, Christopher M. (2018-10-01). "Periwinkle climbing response to water- and airbone predator chemical cues may depend on home-marsh geography". PeerJ. 6: e5744. doi:10.7717/peerj.5744. ISSN 2167-8359. PMC 6171496. PMID 30294513.
{{cite journal}}: CS1 maint: PMC format (link) CS1 maint: unflagged free DOI (link) - ^ Wollerman, Lori; Duva, Maria; Ferrier, M. Drew (2003-09). "Responses of Littoraria irrorata say (Mollusca: Gastropoda) to water-borne chemicals: A comparison of chemical sources and orientation mechanisms". Marine and Freshwater Behaviour and Physiology. 36 (3): 129–142. doi:10.1080/10236240310001603756. ISSN 1023-6244.
{{cite journal}}: Check date values in:|date=(help) - ^ Vaughn, Caryn C.; Fisher, Frank M. (1988-11). "Vertical migration as a refuge from predation in intertidal marsh snails: A field test". Journal of Experimental Marine Biology and Ecology. 123 (2): 163–176. doi:10.1016/0022-0981(88)90167-0.
{{cite journal}}: Check date values in:|date=(help) - ^ Deis, Donald R.; Fleeger, John W.; Johnson, David S.; Mendelssohn, Irving A.; Lin, Qianxin; Graham, Sean A.; Zengel, Scott; Hou, Aixin (2020-11). "Recovery of the salt marsh periwinkle (Littoraria irrorata) 9 years after the Deepwater Horizon oil spill: Size matters". Marine Pollution Bulletin. 160: 111581. doi:10.1016/j.marpolbul.2020.111581.
{{cite journal}}: Check date values in:|date=(help)