The gelling properties of a 0.46 wt % semi-dilute aqueous suspension of well-characterized nanocrystalline cellulose particles extracted from the tunic of marine animals were studied by measuring the time evolution of linear viscoelastic moduli at various frequencies. The results show the existence of a gel time characterized by a frequency-independent loss angle, which suggests that gelling is due to the growth of self-similar clusters, whose fractal dimension was determined.