Year of the Ratfish

They hide in the darkness in the deepest, coldest depths of the ocean, occasionally coming out of the gloom to the delight of scuba divers.

But those in the capital will not have to don diving gear to catch a glimpse of the elusive ratfish, because, from this week to October, they will be able to come upfront with the diminutive creature with the long tail, at the Beijing Aquarium.

"It's the Year of the Rat, so we sent ratfish to Beijing, hoping it can bring good luck to China!" said Gordon Campbell, premier of British Columbia, Canada.

The Vancouver Aquarium delegation held an official ceremony this week to celebrate the collaboration between the aquariums of Vancouver and Beijing.

Hu Weiyong, general manager of the Beijing Aquarium, said this is his aquarium's first display of cryogenic fish such as the ratfish, which live in temperatures between 10-12 C. The aquarium mainly exhibits temperate and subtropical species that prefer 22-28 C waters.

Ratfish forage for food in the sand and mud, so one of the best ways to find them in their natural environment is to swim out onto the sand flats at night, where they can usually be spotted gliding in the water, mouths agape and sifting through the silt in search of clams and small crustaceans.

When caught in the beam of a diver's flashlight, their ghostly silhouettes shimmer metallically and their eyes glow a frosty emerald green.

Ratfish slightly resemble sharks. They have the same cartilaginous skeletons but, unlike sharks, their upper jaws are fused to their brain cases. They also have a flap of skin called an operculum, which covers their gill arches. Another immediately obvious difference is the way they swim. Ratfish move forward by flapping their broad pectoral fins while their skinny, whip-like tails undulate from side to side in a vaguely shark-like way.

Treasures of Canada's Pacific Coast is an exhibition at the Beijing Aquarium featuring six displays of British Columbia's marine fish and invertebrates, including the ratfish, rockfish and sea anemones. The exhibition also features a video presenting British Columbia's diverse and rich coastline.

(China Daily 05/31/2008 page6)