The Common Periwinkle Snail

Littorina Littorea

(All information found on GISD)

Introduction

The common periwinkle snail is a small marine snail found on the Atlantic coast of Europe and North America (as far as Maryland). It is the largest of the periwinkle snails and is considered an invasive species in North America. It has a spiraled, brown shell that can grow up to 52mm , but as the snail gets older this spiral tends to flatten out due to erosion. These snails only live for about 5 years, but tend to cause many problems in North America with their native snails and native algae. However, in Europe they are considered native and are used in many native dishes. Although this snail may be small it has a great impact on it's environment and the organisms around it.

Habitat

Found in the Atlantic in Europe and North America
- Originally introduced to North America in Nova Scotia, but can now be found as far south as Maryland
Can generally be found on rocks in low tide pools and shallow water
- Since they are aquatic they like to stay in wet areas, so they gather in groups on rocks in shallow water

Characteristics

Have lung-like organs that allow them to breath air, but can go for long periods without oxygen
Reproduce sexually, lay eggs (usually 2-9)
Largest periwinkle snail; have brown, pointed shells with whorls
Generally travel in large groups
Have “eye” tentacles, which helps them see and taste

Food/interactions

Herbivores
- Eats algae
They use their radula, which is a tongue like organ, to scrape algae off rocks to eat
- The use of their radula can actually erode rocks overtime
Their most common predator is actually humans
- They are often referred to as edible periwinkles
- They’re considered a delicacy in Europe and are used to make escargot!
Considered invasive in North America because of it's competes with species already native to North America
- it also causes the overgrowth of some types of algae

Taxonomy tree

Domain: Eukaryota
- Kingdom: Animalia

Phylum: Mollusca
- Class: Gastropoda
- Subclass: caenogastropoda
  - Order: Littorinimorpha
    - Family: Littorinidae
      - Genus: Littorina
        Species: Littorina Littorea

Domain: Eukaryote
- Multicellular
Phylum: Mollusca
- soft-bodied invertebrate
Class: Gastropoda
- Snails and slugs with a spiral shell
  - Subclass: Caenogastropoda
    - Marine snails
Order: littorinimorpha
- Large group of snails mainly marine snails, freshwater snails and land snails (used to be under mesogastropoda)
Family: Littorinidae
- Superfamily: littorinidae children
  - Periwinkle; small, round marine snails
Genus: Littorina
- Winkle; refers to small snails that can be eaten
Littorea
- Means shore

Figure 1: Explains the process of autophagy in cells

*Lipofuscin: basically an aging pigment. It can impair cell function and is found mostly in the liver, heart, and brain. For this experiment, however, we’re mainly focusing on the hepatopancreas, or digestive function.

*Autophagic: Self-eating, but in this instance it is talking about the breakdown of old/ damaged cells (waste) to create healthier cells.

Experiment

Scientists wanted to see if depriving common periwinkle snails of their oxidative food (i.e. algae) would improve their cell production rates and reduce the production of lipofuscin* in their digestive cells by removing damaged proteins.
The purpose of this study was to observe autophagic* functions.
They recorded the lipid peroxidation (MDA), lysosomal stability, neutral lipids, and lipofuscin of the snails (both deprived of food and not deprived)
Experiment lasted 7 days
Lowkey animal abuse (they literally took their shells off) , but it’s for scientific purposes I guess

Methods of Experiment

The scientists took common periwinkle snails with a shell length of 20-25 mm
They set up ecosystem tanks making sure every other factor besides food stayed the same- i.e. water temperature, light exposure (day and night) , and pH
10 snails were used in the experimental group as well as the control group with 2 replicates of each snail for research purposes. So in total 40 snails were used
One group was placed in an environment with algae while the other was placed in an environment without it
The snails were in this environment for 7 days and closely observed
After 7 days the scientists used biopsy tools to observe the snails’ hepatopancreas (which in snails is an organ comparable to the human liver)

Conclusion

The scientists proved their hypothesis was correct
- Depriving the snails of their oxygen rich food proved to be beneficial for their lysosomal stability, which means their bodies reduced the production of lipofuscin by getting rid of oxidatively damaged proteins faster through autophagy.
- This shows that the snails can ultimately survive better using autophagy, by making them healthier and potentially can help them live longer (which currently they only live about 5 years)

Figure 2: this graph shoes the data collected from the experiment. In graph A it shows that group T7 fasting has significantly lower levels of lipid peroxidation or degradation compared to the control group. In graph B the experimental group shows significantly higher lysosomal stability compared to the control group, which means through autophagy their healthy cell production was greatly improved.

References

Primary Source:

Global Invasive Species Database (2022) Species profile: Littorina littorea. Downloaded from http://193.206.192.138/gisd/speciesname/Littorina+littorea on 19-09-2022.

Secondary source:

Moore, Michael N, et al. “Anti-Oxidative Cellular Protection Effect of Fasting-Induced Autophagy as a Mechanism for Hormesis.” Proxy Login - University Libraries - USC, 8 Apr. 2015, https://www-sciencedirect-com.pallas2.tcl.sc.edu/science/article/pii/S0141113615000495.

Pictures courtesy of:

http://www.seashoretoforestfloor.com/common-periwinkle-littorina-littorea/

https://www.britannica.com/animal/periwinkle-marine-snail

https://www.jungledragon.com/specie/15558/common_periwinkle.html

http://www.kenstoreylab.com/animal-models-2/invertebrates-2/periwinkle-snail/

https://www.aphotomarine.com/snail_littorina_littorea_periwinkle_edible_winkle.html

Special thanks to Rewordify.com for helping me understand what this experiment and these scientists were talking about :) A LOT of complicated scientific words were used

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