Procedure
Part A: Planarian Anatomy

• Use the image below or in the Lab Report to identify the following structures:
-Anterior intestine
- Cerebral Ganglion
- Lateral Nerve cord
- Mouth
- Pharynx
- Eye cup

Diagram of a planarian with leader lines pointing a variety of structures. A is pointing to a muscular structure that can be protruded though the mouth to suck up food. B is pointing to a single anterior branch of the digestive system. C is pointing to an anterior structure where the lateral nerve cords meet. D is pointing to a cluster of photoreceptors shaped by a cup of pigmented cells. E is pointing to a structure that is located on the ventral surface near the middle of the body, not the head. F is pointing to paired cords that run from the anterior to the posterior of the worm and lie along the ventrolateral sides of the animal. There are many cross branches connecting the two cords.

Part B: Observing Normal Planarian Anatomy in a Living specimen

• With a soft paintbrush transfer a few planarians to a petri dish with spring water.      
• Look at them under the dissecting scope.       
• Use Figure 9.3 to find anatomical structures.       
• Make a planarian squeeze so you can observe both dorsal and ventral surfaces:
-  Take two coverslips
-  Make a ring with petroleum jelly on one coverslip and add a drop of spring water in the middle of the ring.
-  Use a paintbrush to transfer a planarian to the jelly well.
-  Press a second coverslip on gently.
-  Place the squeeze on a slide and observe both sides with a dissecting scope.
-  Answer the questions in Part B of the Lab Report.
• When you are done release the planarian from the squeeze and let it recover.
• Use a different planarian to observe behavior

Part C: Observing Normal Planarian Behavior

• Using a different planarian (let the one from the squeeze recover).
• Place the planarian in a petri dish of spring water.
• Make observations about how the planarian moves in Part C of the Lab Report.
• Flip the planarian over and answer questions in Part C of the Lab Report.
• Poke both anterior and posterior ends and make observations in Part C of the Lab Report.
• Stroke both anterior and posterior ends and make observations in Part C of the Lab Report.
• Add a small drop of liver juice in one part of the dish and create a slight current with a pipette toward the animal and record your observations in Part C of the Lab Report.
• Cover half a petri dish with paper and leave it in the widow near the light. Check it every 15 minuets for an hour. Record your observations in Part C of the Lab Report.

Part D: Planarian Regeneration & Definitions

Figure 9.5- different wats to cut a planarian and what the regenerated organisms will look like. A a cut made to separate the anterior and posterior halves of a single planarian will result in 2 new planarians. B a cut that separates a single planarians left and right halves results in two new planarians. C - on top shows a thin cut taken from the anterior part of the planarian results in a worm with 2 heads growing from the thin cut facing in opposite directions. Below it shows a thin cut taken from the posterior part of the worm results in 2 tails growing out in opposite directions from the thin cut. D shows a T-cut separating the left and right side of the head only results in a a single worm with two heads facing in the same direction.

• You will be making all the cuts shown in Figure 9.5.
- Using a sharp razor separate anterior from posterior (A). Place the anterior piece in a petri dish of spring water labeled "Anterior- A". Place the posterior piece in a petri dish of spring water labeled "Posterior-A".
- Using a sharp razor separate left from right sides (B). Place the right side in a petri dish of spring water labeled "Right-B". Place the left side in a petri dish labeled "Left-B".
- Use a sharp razor to cut a thin slice from anterior and from the posterior end (C) of a planarian. Place the thin anterior piece in a petri dish labeled "Thin Anterior-C". Place the thin posterior piece in a petri dish of spring water labeled "Thin Posterior-C". Dispose of unused pieces of the planarian.
- Use a sharp razor to create a T-cut like the one shown in Figure 9.5D. Place the T-cut planarian in a petri dish of spring water labeled "T-cut-D".
• Be sure to place each of these is a separate and clearly marked dishes. We will examine them next week to see if they regenerated and which parts are regenerated.
• Answer remaining questions in Part D of the Lab Report.