Physiology of Finfish and Shellfish (2+1)

4.4.10. Energy budjet for a hypothetical fish

The relation of non-protein respiration quotient to the percentages of carbohydrate and for metabolized. Illustration

Non-protein respiratory quotient	K cal/l oxygen consumed	Calories derived from
		carbohydrate (%)	Fat (%)
0.707	4.686	0	100.0
0.720	4.702	4.8	95.2
0.760	4.571	19.2	80.8
0.800	4.801	33.4	66.6
0.840	4.850	47.2	52.8
0.880	4.899	60.8	39.2
0.920	4.948	74.1	25.9
0.960	4.998	87.2	12.8
1.000	5.047	100	0

The maximum derobic RQ is unity and nitrogen quotient is 0.148 and any value above that indicates the anaerobic fraction. Anaerobic fraction can be calculated by substracting the aerobic fraction from the total value.

The RQ value for carbohydrate is 1

Fat is 0.71

Protein is 0.81

The metabolisable energy values are 8.66 kcal/gm of distant carbohydrate and 5.66Kcal/gm and digestible protein. Considering other excretory metabolic pathyways of various food source the amount of energy physiologically available to fish from carbohydrate, fat and protein appears to be approximately 4.1, 9.45 and 4.8 kcal/gm respectively.

i. Glucose RQ

C₆H₁₂O₆+6o2 → 6CO₂ + 6H₂O

6CO₂ / 6O₂ → RQ:1

ii. Fat: Tripalmitin

6C₃H₅ (C₁₅H₃₁COO)₃ + 145O₂ → 102CO₂+98H₂O

N

102CO₂ / 145O₂ = 0.703 → 0.71

iii. Protein Respiratory Quotients: 0.81, 0.70, 0.75, 0.80, 0.85, 0.9, 0.95, 1.0

Vs

Calorific value of oxygen: 4.686, 4.739, 4.801, 4.862, 4.924, 4.985, 5.047