Mollusca

The organisms in the phylum Mollusca are called molluscs. Molluscs are characterized as soft bodied organisms that generally have a protective shell. There are at least 50,000 species that are currently living; Molluscs are the one of the most diverse types of animals. (4) This group consists of species from class of bivalves, gastropods, and cephalopods. Their habit varies greatly from terrestrial to aquatic environments. (4) Mollusks have bilateral symmetry. Some of the main characteristics of Molluscs are their radula, a tongue with teeth, a mantle that is between the shell and the body, or like in squids, protects their insides, and all kinds of molluscs have some kind of food/tentacle that helps them move or burrow depending on the species.(3)

Species 1:

Brown Turban Snail - Tegula brunnea (1)

Habitat: Canopy of Kelp Forest (1)

Niche: Food source for sea otter and crabs and it's also a predator of algae (2)

Adaptation: When it is ripped off the ocean floor, it can easily right itself. It has formed the ability to grab pebbles/gravel with its foot and move it from front to back to change its center of gravity. This helps it stay upright and reattach to a rock or kelp. (1)

Life Cycle:

They release sperm and eggs into the ocean where they eggs will be fertilized (1)
The embryos develop into a larvae stage which is planktonic (5)
Then they become juvenile veligers which develop into adult Snails (5)

Sources:

1. "Brown Turban Snail." Brown Turban Snail, Kelp Forest, Invertebrates, Tegula Brunnea at the Monterey Bay Aquarium. Accessed January 23, 2017. https://www.montereybayaquarium.org/animal-guide/invertebrates/brown-turban-snail.

2. "LIMPETS." LiMPETS: Rocky Intertidal Monitoring - Turban Snails. Accessed January 23, 2017. http://sandybeach.limpetsmonitoring.org/invert_turban.php.

3. "Molluscs." Biology Education. Accessed January 23, 2017. http://www.biologyeducation.net/natural-history/molluscs/.

4. "The Mollusca." The Mollusca. Accessed January 23, 2017. http://www.ucmp.berkeley.edu/taxa/inverts/mollusca/mollusca.php.

5. "Tegula Brunnea Philippi, 1848." Tegula Brunnea, Brown Turban Snail. Accessed January 23, 2017. http://filaman.geomar.de/Summary/SpeciesSummary.php?ID=3092&genusname=Tegula&speciesname=brunnea.

Species 2:

Brown Turban Snail - Norrisia norrisii (3)

Habitat: Found in lower rocky intertidal zone, where they graze on algae. Commonly found in shallow subtidal, particularly in kelp forests. (commonly seen crawling up and down stipes of the giant kelp) (3)

Niche: Solitary shells of the snails are then occupied and adopted by hermit crabs to provide shelter. The Brow Turban Snail is also a main food source for sea otters and starfish (1)

Adaptation: Snail is able to retreat into it's shell when picked up or moved from it's position on kelp or rock. Has an "operculum" which is a hard and protective covering that grows with the snail to protect it from predation (1)

Life Cycle: (2)

Starts with the young hatching
- Progresses to adolescent snail feeding until it reaches age of reproduction
The snails would then mate and lay eggs
- Eggs will be deposited in a nest below the soil
Some snails reproduce by spawning
Sometimes rely on external fertilization to reproduce

Sources:

1.) "Brown Turban Snail." Brown Turban Snail, Kelp Forest, Invertebrates, Tegula Brunnea at the Monterey Bay Aquarium. Accessed January 27, 2017. https://www.montereybayaquarium.org/animal-guide/invertebrates/brown-turban-snail.

2.) "Life Cycle of a Snail." Facts About Snails. September 17, 2014. Accessed January 27, 2017. https://factsaboutsnails.com/snail-facts/life-cycle-of-a-snail/.

3.) "Norrisia Norrisi." Norrisia Norrisi. Accessed January 27, 2017. http://www.gastropods.com/3/Shell_2413.shtml.

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