Transcript Crayfish Dissection

Agenda 5/16
• Crayfish Intro PowerPoint
• Crawdad Hole Song
• Dissections: External Anatomy
Crayfish
Dirty Jobs: Crawdads
http://www.discovery.com/tv-shows/dirtyjobs/videos/crawfish-catcher.htm
I. External Features
A. Two segments:
1. Cephalothorax:
a. Fused head and thorax
b. 13 segments covered by a hard
carapace
2. Abdomen:
a. 7 segments
Abdomen
Cephalothorax
Carapace
(Cephalothorax)
I. External Features Cont.
C. Head
1. Most anterior region
a. Antennae, antennules, eyes, and mouthparts
D. Thorax
1. 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 Legs
1. Flexion, extension, and rotation
B. Swimmerets
1. Creates currents to bring O2 to gills
C. Uropods
1. Act as paddle for rapid movement
Walking Leg
Swimmeret
Uropod
II. Movement Cont.
A. Telson
1. Between uropods, houses anuses
2. Further aids in rapid movement
B. Chelipeds
1. 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. Mouth
1. Food enters after broken down by structures
B. Mandibles
1. Bite and crush food
C. 1st/2nd maxillae
1. Move food to throw into mouth
D. Maxillipeds
1. Food manipulation
Mandible
Maxilla
Maxillaped
III. Digestive System Cont.
A. Esophagus
1. Carries food from mouth to stomach
B. Cardiac stomach
1. Stores and chews food
C. Liver (digestive gland)
1. Makes digestive enzymes
2. Completes digestion and absorbs nutrients
D. Intestine
1. Carries solid waste to anus
E. Anus
Digestive Gland
(Dorsal)
Digestive Gland
(Lateral)
Esophagus
Intestine
Stomach
IV. Circulatory System
A. Heart
1. Pumps blood
B. Dorsal abdominal artery
1. Carries blood from heart to abdomen
Heart
V. Respiratory System
A. Gills
1. Used for getting O2 from water
Gill
VI. Excretory System
A. Green Gland
1. Filters liquid waste from blood
2. Like a primitive kidney
Green Gland
VII. Nervous System
A. Brain
1. Coordinates senses and nerve messages
B. Ventral Nerve Cord
1. Carries nerve impulses
C. Eyes
1. 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=W7F0j
Zgdc8A
Crawdad song
https://www.youtube.com/watch?v=23u8CeiN
9OY
• http://www.gvsd.org/Page/1738
• http://www.watchknowlearn.org/Video.aspx
?VideoID=43138&CategoryID=13835