Fig. 4

Derivation of the adipose morphology value from the relationship between lipid droplet size and adipose depot size. (a) Diameter of subcutaneous adipose lipid droplets (LDs) plotted against total depot area. Light grey dots represent individual LDs; dark grey dots represent the mean LD diameter per fish. Black line was fitted using a generalised additive model (GAM; R2=0.85, n=194 fish). (b) Distribution of morphology values, calculated as the residual deviation of each fish’s mean LD diameter from the GAM fit in (a). Positive values indicate larger LDs than expected (hypertrophic); negative values indicate smaller LDs than expected (hyperplastic). Black line shows a normal density fit. (c) Morphology value plotted against number of LDs per fish, showing an inverse relationship (linear model, p=3.9 × 10–6, n=194 fish). Fish with hypertrophic morphology tend to have fewer, larger LDs, while fish with hyperplastic morphology have more numerous, smaller LDs.