ESTIMATION OF WHOLE VOLUME OF GREEN SHELLED MUSSELS USING THEIR GEOMETRICAL ATTRIBUTES OBTAINED FROM IMAGE ANALYSIS

Aquacultured green shelled mussels are an important export product of New Zealand. Using image analysis, several geometrical attributes of live mussels were measured. The volume of individual live mussels was estimated by several methods. When the cubic splines method was applied to top and side view images, volume was estimated with a coefficient of determination of R-2 = 0.97. When only the top view area was used, the R2 decreased to 0.94. When the side view area was also included and empirical equations were fitted to estimate whole volume, the R-2 was 0.97. When measured length, width, and thickness were used to estimate volume, the R-2 was 0.95. There was a wide variation of the measured density of live mussels (1.05-1.27 g/cm(3)). Also, the condition index of the live mussels varied between 48 and 95. There was no correlation between the size of the mussel and its condition index. The mass of the mussel meat could not be accurately predicted by using the whole mass of the live mussel.