Morphometric measurements,condition indexing and dissection of fish

1. MORPHOMETRIC MEASUREMENTS
AND DISSECTION OF FISH
VIJAY
JRF
GandhiInstitute of
Technology

2. •Measuring the length, weight and girth of the fish.
TOTAL LENGTH FORK LENGTH
Notes : Do not pull the flexible tape measure along the curve of the fish

3. WEIGHT MEASUREMENTS
STANDARD LENGTH GIRTH MEASUREMENTS

4. FISH OVERVIEW

5. CONDITION INDEX
GONADOSOMATIC INDEX (GSI)
•Fish body weight and weight of gonad
•Identifying days and seasons of spawning ovaries of
females increase in size just prior to spawning.
Gonadosomatic Index (GSI)
Months
Spawning periods Spawning periods
•Food available to them in water and temperature of water also
Gonads

6. HISTOSOMATIC INDEX (HSI)

7. MATERIAL AND METHODSMATERIALS
•Distilled water
•Blotting paper
•Weighting balance
•Dissection kit including seizer,
•scalpel and blade, tissue paper etc
•Petri dish,watch glass
METHOD
Satirizethe body surface
Blot the fish
Recordthe body weight to the nearest milligram or Grams
dissect the fish and remove the liver and gonads
Removethe moisture of liver and gonads
Weigh the liver and gonads in grams
Liver
Gonads

8. Calculation
H.S.I= Weight of the liver X 100
Weight of the body
G.S.I. = Weight of the gonads X 100
Weight of the body
Note: Result will be documented in grams

9. BIOACCUMULATION
FACTOR (BAF)
•The bioaccumulation of the heavy metals (HM)
in fish tissues were quantified using
bioaccumulation factor (BAF).
•BAF is the ratio of the concentration of a
specific heavy metal in the tissue of the
organism, to the concentration that heavy metal
in the water
BAF= Concentration of HM in dry fish tissue mg/ Kg
Concentration of HM in water mg/ L

11. FISH DISSECTION
MATERIAL
•Newspaper or protective table cover
•Blotting paper
•Scissors, scalpels, filet knives, or
dissecting kits
•Dissecting trays or cutting boards
•Plastic gloves (non-latex)
•Distilled water and disinfectant liquid
•Garbage bag for waste disposal
•Dissecting microscope (optional)
•Hand lens (optional)
Petri dish and watch glass
PREPARATION FOR FISH DISSECTION
•Clean the surface of dissection area
•Cover the area with news paper then
butcher paper on top of news paper.

12. DISSECTION
• DISSECTION STEP 1
• Place the fish in the dissecting pan
• sterilizationof fish with distilled water

13. DISSECTION STEP 2 – Removal of Gills

15. DISSECTION STEP 3 – INCISION
•Alongthe dorsal side of the fish no higher than the lateral line incision toward
the head
•Be careful not to cut too deeply, might destroy some of the internal organs

16. Dissection of internal organs

17. CUT OPEN AS SHOWN
(1) (2)
(3)

18. IDENTIFICATIONOF MALE AND FEMALE

19. LIVER

21. DIGESTIVE SYSTEM

22. KIDNEY

23. HEART

24. SWIM BLADDER

25. Note – Once all organs are removed it can stored in saline solution
To prepare of 1000mL (1 liter) of normal saline.
Calculation :
0.9% NaCl solution - 0.9 gm in 100 ml
100 ml normal saline container 0.9 gm
1 ml normal saline container (0.9/100) gm
1000 ml normal saline container (0.9*1000)/100 gm= 9 gm
Apparatus required (needed) :
1. Chemical balance with weight box.
2. Volumetric flask / 1000 ml
3. Stirrer
4.Reagent bottle 1000 ml
5.Funnel
6.White paper and gum.

26. Procedure:
At first 9 gm of corium chloride (Na cl) are weighted
with balance.
600 ml of distilled water is taken in a
beaker/volumetric flask and added 9
gm NaCl Mixed it properly then distilled water is
added up to 1000 ml.
Then again mixed it with the help of stirrer.
Transferred it to the reagent bottle and labeled.
Now 1000 ml of normal saline is prepared.

27. Part C: Clean Up and Disposal
1. Once your group has finished observing and identifying the
structuresof the perch, it must be
disposed of safely. If there are any excess fluids in your
dissecting tray, please pour them down the
sink with plenty of water.
2. Place all fish and fish tissues directly into the garbage bag
provided by your teacher.
3. Wash your dissecting instruments and dry them to prevent
rusting.
4. Placing dissecting instrumentsback into the kit only when
fully dry.
5. Wash out the dissecting tray with soapy water and lay them
on a common bench to drip dry.
6. Dispose of your gloves with the fish waste and wash your
hands thoroughly.