Fish maw — the swim bladder of a fish — is one of the most expensive dried-seafood products in the world. A Chinese delicacy, it can fetch $450 to $1,000 per kilogram.

Totoaba fish swim bladder, known as maw, can reach around $8,500 (£6,000) per kg in Hong Kong and China, where it is a traditional seafood in the same vein as shark fin, sea cucumber and abalone.

So says when selecting fish maw and other premium dried seafood, consumers have to ensure that each piece is transparent, doesn’t have any worms or a bad smell and most importantly is 100% dry.

The royalty of ingredients are safely behind glass: dried fish maw (bladders), which sell for $4,500 for 1.2 pounds; packs of bird's nest, considered good for women's skin; abalone from Japan ...

Dried fish maw is famed in China as one of the “eight treasures” and ranks alongside bird nests and shark fin in the country’s traditional culinary and medicinal culture.

Dried fish bladders are not something most people would expect to compare to cocaine, and yet that appears to be the world in which we live. Recent reporting from Jo Chandler at Nature explores ...

But high-quality fish maw can sell for eye-watering prices of up to US$2,000 per kg, and its popularity has contributed to overfishing of endangered species such as croaker and sturgeon in recent ...

Different varieties of fish maw — dried swim bladders — on display in a shop in Hong Kong. Credit: Anthony Wallace/AFP/Getty.

Fish maw at Hoi Cheong Ho. Photo: David Wong On Des Voeux Road West, nicknamed “Dried Seafood Street”, about 200 shops have been providing Hong Kong families with their banquet staples for ...

Glossy floors, rough-sawn wood and diffused natural light create a calming atmosphere inside this private museum in Chinese city Shoutou, designed to display a collection of aged fish bladders.