These guidelines to assess the quality/ freshness of whole fish by assessing the general quality attributes of fish viz: appearance of fish outer surface, conditions of fish eyes, gills, belly and vent in the demerit score. Each quality attributes has got sub quality attributes to assess the quality/ freshness of whole fish with different scale of measurements on each quality attributes. The description for checking/ evaluating the quality/ freshness of whole fish in terms of quality attributes is given below. Care must be taken to evaluate physically undamaged fish. Please avoid physically damaged fish from the lot when checking/ evaluating the quality/ freshness of fish.

The developed Fish Quality Index (FQI) ranges from 0 to 1, where 0 represents fish with excellent/ best quality and 1 represents fish with bad/worst quality.

APPEARANCE OF OUTER SURFACE The appearance of surface, status of skin and scales, presence of slime on the surface and stiffness of fish are examined.
1 APPEARANCE OF SURFACE Examine the surface of the whole fish and give appropriate score based on the visibility of surface.
2 SKIN Examine the skin of the whole fish whether they are firm or soft, and give appropriate score.
3 SCALES Examine the scales of the whole fish whether they are firm or loose, and give appropriate score. If scales are not found important for any particular species of fish always select ‘0’ from the demerit score, which will not affect the final Fish quality Index.
4 SLIME Examine the slime in the outer surface/ dorsal region of the whole fish, and based on its intensity in the outer surface/ dorsal region give appropriate score.
5 STIFFNESS Examine the rigor of fish by holding the fish horizontally, if the fish retains the horizontal position then the fish is in rigor stage, if the tail portion of fish is soft and bends then it is pre-rigor stage, if the tail portion of fish is hard and bends then it is post-rigor stage.
EYES The clarity of eye, its shape, visibility of iris and presence of blood are examined.
6 CLARITY Examine the eye clarity of the whole fish and give appropriate mark. If one eye is damaged then examine the other eye.
7 SHAPE Examine the shape of the eyes by looking directly at the eye to see whether the shape is normal or sunken, and give appropriate score.
8 IRIS Examine the iris of the eyes to see whether it is visible or not, and give appropriate score according to visibility.
9 BLOOD Examine the ingression of blood in the eyes and give appropriate score.
GILLS The color, presence of mucus and odour of gills are examined by lifting the opercula of the fish.
10 COLOUR Examine the colour of the gills and give appropriate score as per given scale.
11 MUCUS Examine the presence or absence of mucus in the gills and give appropriate score.
12 ODOUR Smell the gill and give appropriate score.
BELLY The colour changes of belly region and its firmness are examined.
13 DISCOLORATION Examine the colour changes in the belly region and give appropriate score.
14 FIRMNES Examine the firmness of belly region by pressing slowly and give appropriate score.
VENT The condition and odour of vent are examined.
15 CONDITION Examine the vent condition of fish to see whether it’s normal or exudate coming out and give appropriate score.
16 ODOUR Smell the vent part and give appropriate score.