Morphometric measurements,condition indexing and dissection of fish
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The document summarizes the process of measuring and dissecting fish. It outlines the steps to measure various metrics of fish bodies externally including total length, fork length, weight, and girth. It then describes the process of dissecting fish internally and identifying and removing organs like the gills, digestive system, kidney, heart and swim bladder. The purpose is to calculate indices like the gonadosomatic index (GSI), histosomatic index (HSI), and bioaccumulation factor (BAF) which provide information about spawning periods, food availability, and heavy metal concentration in fish tissues respectively. Safety procedures for dissection and proper disposal of fish waste are also outlined.
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
- 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
- 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.