Adults: Shell large (to 230 mm), somewhat elongate, slightly arched, hardly convex, medium weight to heavy. Spire low, visible in ventral view. Holes small, round, strongly raised, usually 7-10 open. Dorsal surface with tightly spaced, narrow, sharp, radial lamellae. Lamellae may be discontinuous between suture and row of holes. At row of holes, shell at distinct obtuse angle between dorsal surface and area in between row of holes and columella. Columella in anterior part of medium width forming acute angle between row of holes and columella proper, in posterior part forming broad convex shelf protruding over margin of shell, forming ledge below row of holes. Color uniform; rust red (east coast), white (west coast). Spire region usually eroded by scouring or boring organism, showing blueish nacre. Nacre with milky base color, patches with blue and green pigment color, and irregular dark conchiolin deposits. Nacre in spire region usually without red pigment. Muscle scar with indistinct border, broad spiral striation, and irregular crenellation.
Juveniles (< 30 mm): Shell slightly elongated, lightweight, depressed, flat, not arched. Holes medium sized, hardly raised, usually 5-7 open. Dorsal surface with spiral depression between suture and row of holes. Lamellae missing, no spiral cords, only approximately 50 fine spiral striations. Columella narrow over entire shell. Protoconch blood red. Earliest part of teloconch (to approximately 15 mm) always dark colored, subsequently either dark (east coast) or light (west coast). Nacre milky white in light specimens, blueish in dark specimens, no or little conchiolin deposits, spire region usually with red pigment. No muscle scar.

The « Midas Ear Abalone », locally known as « Perlemoen », is a large haliotid endemic to South Africa with a beautifully radiating wave-like sculpture. A grazing gastropod feeding primarily on encrusting algae as juveniles and a variety of seaweed and drift algae as adults, it is a common species inhabiting moderately exposed rocky shores from intertidal waters down to about -30m deep. It is the only comm.ercially important abalone species in South Africa, traditionally harvested for the meat and exported to Asian markets where the demand for its meat is very high. Since the 1960s it started to show signs of over-exploitation, and the stocks declined rapidly after entering the 21st Century leading to the South African government closing the fishery completely in February 2008. For the same reason it was listed in CITES Appendix III by South Africa on May 2007, although it was then deleted on June 2010. Nevertheless, illegal fishing and poaching continues today and products are often exported from nearby countries such as Namibia and Mozambique. Captive-bred aquacultural business also exist, producing live specimens often seen for sale on the markets of Hong Kong and China. Its shell is comm.only sold as home decor in the polished and dyed state, natural shells in good condition are surprisingly difficult to find. In its natural habitat it is usually heavily encruscted by marine overgrowth and the characteristic undulating sculpture is often completely concealed. The dorsum colouration may vary from yellowish to dark red, the internal is iridescent and often carry bluish patches in large specimens. Typical shell length around 150mm., extremely large specimens may exceed even 220mm.

The habitat of H. midae changes markedly with size. Animals up to 10 mm shell length live on red encrusting algae (Lithothamnion), between 10-35 mm under boulders, between 40 and 100 mm in narrow crevices, and specimens greater than 100 mm shell-length live on top of rock. The animals migrate from the intertidal area at sizes around 10 mm to 25 m depth with age, and prefer areas of intermediate exposure (Newman, 1968; Muller, 1984b).

Adults are easy to identify; the characteristic lamellae start to be formed in specimens of approximately 3 cm. Juvenile H. spadicea from South Africa are more elongate, convex, bear approximately a dozen spiral cords, and have larger holes. The red color in the nacre of the spire region may be found in H. spadicea and H. midae.

Type locality: Indian Ocean and Cape of Good Hope. By original designation.
Range: South Africa: St. Helena Bay to WestTranskei