Script for
Ocean Critters

This slideshow is designed for lower primary.  Main focus is to compare fresh and marine water and the critters in marine water that either make shells or bones.

Slide 1.  Ocean Critters  (1 slide loops)

·       Many organisms live in the oceans, some are large like whales and sharks.  Others are small like one celled protozoa.  

·       Some have shells like many invertebrates usually made of calcium carbonate or silica

·       Critters with shells may be preserved as fossils

·       Some are plants like the giant kelp to one celled diatoms

·       Some organisms like many land plants and fungi, cannot survive in salt water  

Slide 2.  What is difference between fresh and ocean water?  (1 video of rotating earth)

·       Water makes up about 71% of the earth’s surface

·       Ocean water makes up  96.5%.  Ocean water is salty created by erosion over time

·       Fresh water makes up 3.5% of total water and  is usually free from salts

·       Most land plants and animals require fresh water for their biological system to work.

Slide 3.  Fresh  Water  (2 slides fade)

·       Fresh water is created through melting ice, rain water

·       Has many “salts” dissolved in the water

·       Important nutrients for many critters

·       Helps them make shells

·       Fresh water is easier on organisms since they do not have to remove salts

Slide 4.  Salt Water  (2 slides fade)

·       Salt or marine water has a concentration of 35 parts per thousand or 3.5% of the weight of seawater comes from dissolved salts

·       Many ocean animals have to adapt

·       Fish, mammals, and reptiles have had to adapt to this salt content and develop systems to remove it through their digestive system


Slide 5.  Shell or Bone (2 slides fade)

·       Organisms in the oceans use shells to protect themselves

·       Organisms in the oceans that have bone have modified structure due to less gravity in waters

·       Invertebrates would have shells

·       Vertebrates would have bones

·       Shells can be made of calcium carbonate or silica dioxide

·       Bones are calcium phosphate

Slide 6   Ocean critter with Bones (3 slides fade)

·       Vertebrates like whales, most fish, otters have bones (vertebrates)

·       Fish have created a way to extract dissolved oxygen out of the water through gills

·       Created a way to remove salts through poop

·       Mammals and reptiles need to breathe atmosphere

Slide 7.  Ocean Critters with Shells (4 slides fade)

·       Uses a form of calcium carbonate and silica dioxide

·       Intricate ways for protection

·       Each organisms body and shell evolved together

Slide 8.   Diatoms (One Celled Plant)   1 video

·       Diatoms  have a siliceous  skeleton or frustule

·       They photosynthesize

·       Only found where light can penetrate

·       They are important as the beginning of food chair especially for Protista

·       Size is very small

Slide 9.    Foraminifers  (Protista, one cell) 

·       Protista with shell of calcium carbonate

·       Prefer warm water

·       Food for invertebrates

·       Live in mud (benthic) or water column (planktonic)

Slide 10.   Radiolarians  (Protista, one cell)

·       One celled protozoa that make siliceous skeletons or shells

·       Eats diatoms and many invertebrates eat

·       One of the oldest organisms in the fossil record

·       Prefers cold nutrient rich waters, upwelling zones     

Slide 11.  Porifera (Sponges)

·       Primitive invertebrate without organs

·       Eats through water pumped through and nutrients are captured, no active way of eating

·       Some sponges were used to clean hence the term “sponge”

Slide 12.  Cnidaria

·       Primitive invertebrate with limited organs like a stomach

·       There are many types without hard parts

·       Jellyfish have tentacles and noted for stinging cells

·       Sea anemone have tentacles that grow upward from a stalk

Slide 13.  Cnidaria (Corals)

·       “Stone Coral” refer to cnidaria with an internal shell

·       Polys or the living organisms are connected like an apartment house

·       Tentacles give the living coral color

·       To help support the living coral there are walls called septa

·       Coral prefer clean warm water

Slide 14.    Mollusca (Diverse Group)

·       Mollusk is a diverse group of organisms including clams to octopi

·       This shows the monoplacophora, Polyplacophora (chitins), Scaphopoda, bivalves, gastropods and Cephalopoda.

·       They have a “foot” that helps them move

·       They have a siphon to take water in so the organisms can filter out food

Slide 15.   Mollusca  (Gastropod)       

·       Both marine, land and fresh water

·       Shell is asymmetrical and spirals

·       Some are low or high spiral

·       Snails have antennae

·       Can be carnivore or herbivore

·       Carnivores have a “radula” that can bore into other shells and suck out food

Slide 16.  Mollusca (Bivalves)  

·       Bivalves have 2 equal shells, they are bilaterally symmetrical

·       Living part is protected by shell

·       Siphon comes out to filter water for food (filter feeder)

·       “Foot” helps movement in benthic zones

Slide 17.   Arthropods (crabs, lobsters)

·       External skeleton that molts as the animal gets larger

·       Skeleton is made of chiton, so “soft shell”

·       Includes crabs to small microscopic organisms; krill is eaten by Baleen whales

·       Processes claws for movement and protection

Slide 18.  Echinoderms  (Sand Dollars, Seastars)

·       Possess 5 part symmetry which moves water through their system

·       Hydraulic system is used for food, reproduction, movement

·       Includes sea urchins, seastars, sand dollars

·       Prefer warm water and makes shell of calcium carbonate

Slide 19.   Shells from Indian Ocean (1 video)

·       Indian Ocean is a very productive area

·       Nutrients from the rivers flowing into the Indian Ocean makes a productive area

·       Mollusca live along the shores and can be found as “shell beaches”

·       Indian shells are sold throughout the world

Slide 20.   Interpreting fossil layers (video)

·       In Santa Cruz County there is a beach side community called Capitola

·       It has a great beach but also exposed are some very steep cliffs

·       The video shows the view

·       If you look closer at the cliffs you see fossils

Slide 21.  Purisima Formation

·       A formation in geologic terms means an ancient environment that can be traced for distance

·       Purisima Formation reflects terraces where the clams live in the sandy mud

·       Large storms would rip up the clams and deposit them again into a storm layer deposit

Slide 22.  Rocks with Fossils (2 fades)

·       Rocks hold secrets and fossils can tell you what happened

·       Marine fossils are more abundant since they are buried easily

·       Rocks with radiolarians… these ribbon cherts (siliceous) are from the Marin Headlands just north of Golden Gate Bridge

·       Radiolarian represent areas that are cold water and upwelling conditions

·       Eden Canyon is an area that was sandy conditions and they show bivalves in the sandstones