[2] It is highly sought after by criminal organisations and a thriving black market exists for it, leading to a catastrophic decline in stocks.

The distance of the apex from the margin about equals one-fifth the greatest length of the shell.

The surface shows strong, elevated, radiating wrinkles or lamellae, but no spiral markings when adult.

[5] H. midae is endangered due to severe overfishing from uncontrolled poaching driven by consumer demand in East Asia; 90% of exports go to Hong Kong.

In most areas of former abundance, evidence indicates that populations have not been able to keep up with the level of poaching, leading to recruitment failure.

[6] The threat to the perlemoen led it to being banned from all types of harvesting and listed on CITES and the National Environmental Management: Biodiversity Act 10 of 2004 (NEMBA); it was later removed from both registers due to pressure from the fishing industry.