Echinoderms and Marine Arthropods: Unit 8

echinodermata means

spiny skin

Echinodermata are animals with…

bilateral symmetry as a larvae, and radial symmetry as an adult

Only this Phylum has the presence of a

water vascular system

Echinoderms have a

endoskeleton that is composed of calcium carbonate

What type of symmetry do echinoderms and cnidarians have?

Radial

Asteroidea (Sea Stars)

Cushion Star, Spiny Starfish

Holothuroidea (Sea Cucumbers)

Hairy Sea Cucumber, Giant California Sea Cucumber

Echinoidea (Sea Urchins & Sand Dollars)

Sand Dollar, Purple Sea Urchin, Long Spined

What is a water vascular system and how is it used in echinoderms?

Water enters system through the madreporite and circulates through a series of canals and tube feet.

What is a keystone species and why are sea stars considered a keystone species in the rocky intertidal zone?

A keystone species is a species that has a large effect on its ecological system. Sea stars are considered keystone species because they prey on other invertebrates which control their population.

Put the following structures in order from outside the echinoderm to the last structure in the water vascular system.

Ocean, Madreporite, Stone Canal, Ring Canal, Radial Canal, Ampullae, Tube Foot

What is the difference from Benthic and Pelagic?

Benthic: Bottom of the ocean, Pelagic: Ocean water

Holothuroidea (Food)

Scavengers, Feed on Debris

Asteroidea (Food)

Bi-valves (Clams, Oysters, and Mussels), Snails, Small Fish

Echinoidea (Food)

Algae, Plankton

How does ocean acidification impact marine animals with a calcium carbonate shell or endo/exoskeleton?

Ocean acidification impacts marine animals with calcium carbonate shells making it harder for them to build shells.

Give 4 reasons why the arthropods are the most successful group of animals on the earth.

Body segmentation (flexibility), a hard exoskeleton, jointed appendages, complex sensory organs

Under the walking legs are the ___ , so the crayfish walks, its creates waterflow across this structure so that it can extract oxygen from the water to breathe

Gills

Marine arthropods are in the subphylum…

Crustaceans

Like all arthropods, the marine arthropods have an exoskeleton made of chitin. Give two functions and one limitation

Important functions: protects animal and provides points of attachment for the muscles that move appendages limitation: bulky and heavy

Name 5 Crustaceans

Crabs, Crayfish, Barnacles, Krill, Copepod

Characteristics of barnacles

Only sessile crustaceans, attaches using secreted cement, feathery appendages, hermaphrodites, cross fertilize

Characteristics of Copepods

Most abundant type of zoo plankton in all of the ocean, single most important group of animal plankton, eat phytoplankton

Characteristics of Krill

Shrimp like feeders, bioluminescent, large swarms, consumed by whales, seals, penguins

How are barnacles different from crabs/lobsters/shrimp?

Barnacles are sessile and filter feed, whole crabs, lobsters and shrimp are motile.

Why is molting and why do arthropods molt?

The exoskeleton sheds and a new one is produced.

Why are arthropods most vulnerable after molting?

Their soft bodies are exposed to predators and they also have a difficult time moving.

How are swimmerets different from walking legs?

Swimmerets: create water currents and function in reproduction

Walking legs: important for locomotion which allows them to move across

How are maxillipeds different from chelipeds?

Maxillipeds: hold food during eating

Chelipeds: large claws used to capture prey

How do swimmerets, walking legs, and maxilipeds, and chelipeds have in common?

They are all jointed appendages

What are two types of zooplankton? What do they eat?

Ex: Copepods and Crustaceans

They eat phytoplankton