EO dissection in B. pinnicaudatus 1 of 2
I. Electric organ dissection in Brachyhypopomus pinnicaudatus.
Materials:
- A fish
- A scalpel
- Sterno saline with glucose
- Sylgard-coated dissection dish with 2-3 minutien pins
- Fine dissection scissors (Vannas spring scissors usually work best)
- 2 pair forceps (handling will be fairly rough, so don’t use your good forceps!)
1. Clip off a section of caudal tail filament from the fish. (Figs. A & B)
2. Trim off 3-4 mm of the tail tip (Fig B)
3. Pin the tissue in a dissection dish filled with Sterno saline (Fig C)
4. Using fine Vannas dissection scissors, make a continuous cut through the skin along the dorsal ridge, then cut the skin along the ventral ridge (Fig. D). When cutting the skin with the dissection scissors make your cuts as shallow as possible to avoid nicking the electrocytes.
5. Working on the caudal end now, grasp one piece of skin with a pair of forceps, then grasp the electric organ and the skin on the other side with another pair of forceps. Peel the skin off from caudal to rostral end (Fig. D).
6. Let the tissue sit for ~15 min in saline. Any electrocytes damaged during the dissection will shrink and become opaque as in the following figure. Electrocyte outline is indicated in red. The elecrocytes at the top of the tissue are damaged.
Note: the tissue at either end of the tail segment will be damaged by the pinning/grasping/pulling. This is unavoidable if you are going to complete the dissection quickly. Experience has shown that it is best to sacrifice a little tissue in the interest of completing the dissection quickly. Once the electric organ is exposed to the saline the electrocytes will remain quite happy for hours on end. Without removing the skin, the electrocytes decline rapidly.
Created: 9-Mar-07
Edited: 9-Mar-07
M. R. Markham