Day 13 Molluscs
Today is your test on worms
Phyla Mollusca
The phylum Mollusca includes animals like snails, clams, octopuses, squids, etc
-There are more species of Molluscs in the ocean than any other phylum.
-There are over 200,000 species of Molluscs
-The only phylum that has more species than that is the Arthropods on land
Watch this video on the phyla Mullusca. Create a box in your sketchbook, title it "The Phylum Mollusca" and take notes, write down interesting things that you learn from the video and include an image in your sketchbook. Make sure you understand the characteristics of molluscs and what they are.
Mollusc Characteristics
-Soft bodies (no bones)
-Enclosed in a calcium carbonate shell (most species)
-Body covered in a mantle (a thin layer of tissue that secretes the shell)
-Unsegmented
-Bilateral
-Ventral, muscular foot used for locomotion
-Radula (a tooth covered tongue)
-Gills
-Reduced coelom
Radula
Classes of Molluscs
There are many classes of Mollusks but we are only going to learn three.
Classes of Mollusk
-Class Bivalvia- Hinged between two shells, clams, mussels, oysters, scallops
-Class Gastropoda- Body distorted by torsion when there is a shell, Slugs, snails, Nudibranchs, Limpets
-Class Cephalopoda- Tentacles and siphon, squids, octopuses, cuttle fish, and the nautilus
These are the other five classes of molluscs that we are not going to learn in marine biology. Feel free to look them up, research them, or include them in your sketchbook if you are interested.
-Class Caudofoveata- Worm like deep water marine molluscs with a cylindrical shell
-Class Aplacophora- Lacking shell, mantle, and foot, worm like marine borrowers
-Class Polyplacophora- Have eight dorsal plates, Chitons
-Class Monoplacophora- Single arched shell, Neopilina
-Class Scaphopoda- Inclosed in a tubular shell, has tentacles, Dentalium
Class: Gastropoda (Stomach foot)
-Largest group of molluscs
-75,000 species
Common Name for all gastropods is Snail (Gastropod)
Orders of Snails
Order: Vetigastropoda
Order: Caenogastropoda
Order: Heterobranchia
Snails
The violet snail makes a raft of air bubbles
Adopt a snail assignment
-Choose a species of marine snail (must be marine).
-You are going to draw that snail or print a picture of it and write all about it. Write where it lives (location in the world), what habitat it lives in, what it eats, what eats it, and an interesting fact about that snail. Next class you are going to teach the class about the snail you adopted.
EVERYONE in the class has to choose a different species of marine snail. Here is the link to the Snail signup sheet
Snail Anatomy
Because the shell of a snail only has one opening their body plan is twisted. This twisted body plan is called torsion
Watch this video on cone snails. Create a box in your sketchbook, title it "cone snails" and write down interesting things that you learn from the video and include an image in your sketchbook.
This is an optional video. Just an extra cone snail video.
Order: Patellogastropoda
Common Name: True Limpets (Gastropod)
The limpet is a type of snail. They are a common snail to talk about in marine biology because they can be found in every tide pool.
Order: Archaeogastropoda
Family: Haliotidae
Common Name: Abalone (Gastropod)
Abalone and Limpet anatomy
Order: Nudibranchia
Common Name: Nudibranchs or Sea Slugs (Gastropod)
Some times called sea slugs
-The some times eat sponges
-They are usually poisonous
-Sometimes save the nematocysts of cnidaria that they have eaten and can then use the venom
-Lost their shell. Their mantel no longer creates a shell
-Have exposed gills
Watch this video on Sea SLugs. Create a box in your sketchbook, title it "sea slugs" and write down interesting things that you learn from the video and include an image in your sketchbook. There is a lot of information about sea slugs in this video. Write down some good information in your sketchbook.
Watch this video on Sneaky sea slugs. Create a box in your sketchbook, title it "sea slugs" and write down interesting things that you learn from the video and include an image in your sketchbook.
Watch this video on The watermelon sea slug. Create a box in your sketchbook, title it "watermelon sea slug" and write down interesting things that you learn from the video and include an image in your sketchbook.
Watch this video on The sea butterfly. Create a box in your sketchbook, title it "Sea Butterfly" and write down interesting things that you learn from the video and include an image in your sketchbook.
Class: Bivalvia (Two Valves)
(Too many different orders)
Common Name for all bivalves is Clam
This is an interested but optional video on using clams for science
Enjoy this video for a few seconds of a clam using its foot to collect salt.
Watch and enjoy this short Johnathan Bird video where he puts his hand in a giant clam
Family: Ostreoidea (A type of Clam)
Common Name: Oysters (Bivalvia)
Family: Mytilidae (Type of Clam)
Common Name: Mussels (Bivalvia)
Parts of a Mussel
-Umbo- oldest part of the shell
-Adductor muscles- used to close the valves
-Byssal threads- used by mussels to attach to things