GB/T 18654.8-2026Inspection of germplasm for fishes - Part 8: Determination of oxygen consumption rate and critical asphyxiation point (English PDF)

Foreword

This document complies with the provisions of GB/T 1.1-2020 "Standardization Work Guidelines Part

1.Structure and Drafting Rules of Standardization Documents". Drafting. This document is Part 8 of GB/T 18654 "Fish Germplasm Inspection". GB/T 18654 "Fish Germplasm Inspection" has been published as follows: part.

1.Inspection Rules;

2.Sampling Methods;

3.Characteristic Determination;

4.Measurement of Age and Growth;

5.Dietary Analysis;

6.Determination of reproductive performance;

7.Ecological Characteristics Analysis;

8.Determination of Oxygen Consumption Rate and Critical Asphyxia Point;

9.Meat Percentage Determination;

10.Determination of muscle nutrient composition;

12.Karyotype Analysis;

13.Isozyme Electrophoresis Analysis;

1 Scope

GB/T 18654.8-2026 is the Chinese national standard covering how much oxygen a fish uses and the concentration below which it dies - the two numbers that set the stocking density of a pond and the aeration a farm has to run through a summer night. It replaces GB/T 18654.8-2008 and has been in force since 1 September 2026, one of the parts of the GB/T 18654 fish germplasm inspection series revised together. It was issued on 27 February 2026 and has been in force since 1 September 2026, replacing GB/T 18654.8-2008. The document is under the responsibility of the Ministry of Agriculture and Rural Affairs. This page is published from the official record of the 2026 edition; the clause text of a standard this recent is not yet in circulation, and the figures, limits and tables it contains are those of the document itself, delivered in full with the English translation.

This document describes the experimental conditions, reagents or materials, instruments and equipment, samples, experimental procedures, and methods for determining the oxygen consumption rate and critical asphyxiation point of fish. Experimental data processing methods. This document applies to the determination of oxygen consumption rate and critical asphyxiation point in fish.

4 Test conditions

4.1 The test should be conducted indoors in a quiet environment, away from direct sunlight.

4.2 The test water should be filtered and aerated, and the dissolved oxygen content should not be less than 7 mg/L.

4.3 During the experiment, the air temperature, water temperature, pH value, flow rate and salinity remained stable.

5.Reagents or materials Comply with the provisions of GB/T 7489 and HJ506.

6 Instruments and Equipment

6.1 Test apparatus for fish oxygen consumption rate and critical asphyxiation point The device should ideally consist of a water storage tank, a breathing chamber, water pipes and valves, and a dissolved oxygen meter, as shown in Figure

1.It is not limited to commercially available instruments. The breathing chamber shown in the diagram is a tank-type breathing chamber; a racetrack-type breathing chamber or other similar devices may also be used. The breathing chamber should preferably be transparent and airtight. A sealed cylindrical acrylic container (with a lid at one end, rubber sealing rings around the edges, and bolts to secure it tightly). The breathing chamber typically has a capacity of... The capacity ranges from 20L to.200L. The volume of the breathing chamber is selected based on the size of the sample fish. The mass ratio of sample fish to water is approximately 1.20.Dissolved oxygen... The measuring instrument should meet the requirements of HJ506.

6.2 Electrochemical Probe It meets the requirements of HJ506.

7 Samples

7.1 Sampling shall be carried out in accordance with the method of GB/T 18654.2.

7.2 The sample fish were of basically the same size and in good health. Each experimental group contained no fewer than 10 sample fish.

8 Test Procedure

8.1 Determination of Dissolved Oxygen Perform according to the methods of GB/T 7489 or HJ506.

9 Experimental Data Processing

9.1 Oxygen Consumption Rate The measured oxygen consumption of the sample fish each time is the difference between the dissolved oxygen levels of the water entering and leaving each time, calculated according to formula (1).

9.2 Critical Asphyxiation Point When 50% of the sample fish lose balance, become comatose, or lose the ability to swim, and the dissolved oxygen concentration does not fluctuate significantly, the dissolved oxygen level in the breathing chamber water... The measured value is the critical suffocation point. GB/T 18654.8-2026. Fish germplasm testing - Part 8. Determination of oxygen consumption rate and critical asphyxiation point ICS

50 National Standards of the People's Republic of China Replaces GB/T 18654.8-2008 Fish germplasm testing Part

8.Determination of Oxygen Consumption Rate and Critical Asphyxia Point Published on 2026-02-

27 Implemented on 2026-09-

01 State Administration for Market Regulation The State Administration for Standardization issued a statement.