The cuttlebone of this species is small, two-thirds to three-quarters the length of the mantle, and positioned in its anterior. Characteristic of the genus "Metasepia", the cuttlebone is rhomboidal in outline. Both the anterior and posterior of the cuttlebone taper gradually to an acute point. The dorsal surface of the cuttlebone is yellowish and evenly convex. The texture throughout is smooth, lacking bumps or pustules. The dorsal median rib is absent. A thin film of chitin covers the entire dorsal surface. The cuttlebone lacks a pronounced spine; if present, it is small and chitinous. The striated zone of the cuttlebone is concave, with the last loculus being strongly convex and thick in the front third. The sulcus is deep and wide and extends along the striated zone only. Striae (furrows) on the anterior surface form an inverted V-shape. The limbs of the inner cone are very short, narrow, and uniform in width, with the U-shape thickened slightly towards the back. The cuttlebone of "M. pfefferi" does not possess an outer cone, unlike that of most other cuttlefish species.