MORPHOMETRIC MEASUREMENTS

AND DISSECTION OF FISH

VIJAY JRF Gandhi Institute of Technology

•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

WEIGHT MEASUREMENTS

STANDARD LENGTH GIRTH MEASUREMENTS

FISH OVERVIEW

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

HISTOSOMATIC INDEX (HSI)

MATERIAL AND METHODS

MATERIALS

•Distilled water

•Blotting paper

•Weighting balance •Dissection kit including seizer,

•scalpel and blade, tissue paper etc

•Petri dish,watch glass

METHOD Satirize the body surface

Blot the fish

Record the body weight to the nearest milligram or Grams

dissect the fish and remove the liver and gonads

Remove the moisture of liver and gonads

Weigh the liver and gonads in grams

Liver

Gonads

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

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

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.

DISSECTION

• DISSECTION STEP 1

• Place the fish in the dissecting pan

• sterilization of fish with distilled water

DISSECTION STEP 2 – Removal of Gills

DISSECTION STEP 3 – INCISION

•Along the 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

Dissection of internal organs

CUT OPEN AS SHOWN

(1) (2)

(3)

IDENTIFICATION OF MALE AND FEMALE

LIVER

DIGESTIVE SYSTEM

KIDNEY

HEART

SWIM BLADDER

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.

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.

Part C: Clean Up and Disposal 1. Once your group has finished observing and identifying the structures of 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 instruments back 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.