The shell of Acanthocardia aculeata can reacha size of 50–115 mm. This shell is robust, broadly oval, with a heart-shaped profile, equivalve and inflated, with crenulated margins. The surface shows 20-22 prominentradialribs, with rows of sharp spines, especially at sides. The basic coloration is usually pale brown. The interior is white, with grooves extending throughout the inside.