Agenda 5/16

• Crayfish Intro PowerPoint

• Crawdad Hole Song

• Dissections: External Anatomy

Crayfish

Dirty Jobs: Crawdads

http://www.discovery.com/tv-shows/dirty-jobs/videos/crawfish-catcher.htm

I. External Features

A. Two segments:1. Cephalothorax:

a. Fused head and thoraxb. 13 segments covered by a hard

carapace 2. Abdomen:

a. 7 segments

Abdomen

Cephalothorax

Carapace (Cephalothorax)

I. External Features Cont.

C. Head1. Most anterior region

a. Antennae, antennules, eyes, and mouthparts

D. Thorax1. Posterior to the head

a. walking legs and chelipeds attached

b. Contains heart, liver, and gills

External View (Dorsal)

External View (Ventral)

Antennae

Antennule

Eye

II. Movement

A. Walking Legs1. Flexion, extension, and rotation

B. Swimmerets1. Creates currents to bring O2 to gills

C. Uropods1. Act as paddle for rapid movement

Walking Leg

Swimmeret

Uropod

II. Movement Cont.

A. Telson1. Between uropods, houses anuses

2. Further aids in rapid movement

B. Chelipeds1. Self defense

2. Grab and manipulate food

Cheliped

Telson

Agenda 5/19

• PowerPoint: Crayfish

• Video: Crayfish Dissection

• Dissection: external #16-18

Internal # 1-13

III. Digestive System

A. Mouth1. Food enters after broken down by structures

B. Mandibles1. Bite and crush food

C. 1st/2nd maxillae1. Move food to throw into mouth

D. Maxillipeds1. Food manipulation

Mandible

Maxilla

Maxillaped

III. Digestive System Cont. A. Esophagus

1. Carries food from mouth to stomach

B. Cardiac stomach1. Stores and chews food

C. Liver (digestive gland)1. Makes digestive enzymes

2. Completes digestion and absorbs nutrients

D. Intestine1. Carries solid waste to anus

E. Anus

Digestive Gland (Dorsal)

Digestive Gland (Lateral)

Esophagus

Intestine

Stomach

IV. Circulatory System

A. Heart1. Pumps blood

B. Dorsal abdominal artery1. Carries blood from heart to abdomen

Heart

V. Respiratory System

A. Gills1. Used for getting O2 from water

Gill

VI. Excretory System

A. Green Gland1. Filters liquid waste from blood

2. Like a primitive kidney

Green Gland

VII. Nervous System

A. Brain1. Coordinates senses and nerve messages

B. Ventral Nerve Cord1. Carries nerve impulses

C. Eyes1. Focus light

D. Antenna/antennules 1. Used for touch, taste, smell, and balance

Ventral Nerve Cord

Ventral Nerve Chord Posterior

Eggs

Female

Male

Gonad

Crayfish birth

Note* Swimmerets hold larva

•http://www.watchknowlearn.org/Video.aspx?VideoID=39090&CategoryID=13835

Dissection

• https://www.youtube.com/watch?v=W7F0jZgdc8A

Crawdad song

https://www.youtube.com/watch?v=23u8CeiN9OY

• http://www.gvsd.org/Page/1738

• http://www.watchknowlearn.org/Video.aspx?VideoID=43138&CategoryID=13835