Crustaceans

Where do crustaceans mostly reside?

In the sea, so they are aquatic.

What are 3 things that characterize crustaceans?

• Hard exoskeleton

• Two pairs of antennae

• Mandibles

What are the main crustacean body parts?

1. Head

2. Thorax

3. Abdomen

What have the head and the thorax in many crustaceans been merged to form?

Cephalothorax

What is the cephalothorax coevered by?

A carapace.

What differs in the exoskeleton of crustaceans that sets them apart from other arthropods?

It contains calcium carbonate, which is why their exoskeleton is so hard and stony.

What are the first two appendages in crustaceans? What do they bear?

“feelers” called antenna. They bear many sensory hairs

What can antennae serve as? 3 things.

1. A primary sense organ (in species such as crayfish)

2. Filter feeding

3. Water fleas use them as oars to push them through water

What are the third pair of appendages in crustaceans called?

Mandibles are are mouthparts used by most species to bite and grind food.

How are mandibles used in different ways?

1. to bite and grind food

2. In some species, mandible are bristly structures for filter feeding

3. Problike structures used to find+pick up detristus

4. Needlike structures used to such food from the host

How do the appendages on the thorax and abdomen vary between species? List examples.

1. (filter feeding)

2. (swimming)

3. (various other tasks)

What are the pair of large claws used for in crayfish? Where are they located?

To catch prey, pick it up, crush it, and cut it. It is located on the thorax.

What other appendages in a crayfish are also located on the thorax?

4 pairs of walking legs.

What are swimmerets and where they are located

Flipperlike appendages used for swimming. Located on the abdomen.

Where are the paddlike appendages ona crayfish located?

Second to last abdominal segment

What parts make up a large, flat tail in crayfish?

• Paddlelike appendages

• final abdominal segment

What happens when the muscles of the abdomen contract in a crayfish? What does this do?

The crayfish’s tail snaps forward, provideing a powerful swimming stroke that has the power to pull the animal backwards rapidly

What type of appendages do barnacles have?

Featherlike appendages used for filter feeding.

What are thoracic or abdominal appendages built like for in swimming or walking species?

Legs and paddles

What are some other modifications of appendages in crustaceans?

They may be adapted for carrying eggs, internal fertilization, burrowing, or spearing prey.