In 2003, the hit Pixar animation Finding Nemo sparked a craze for clownfish, with Singapore retailers reporting increased sales of the orange-and-white striped creatures that went for a couple of dollars.
This year, its sequel Finding Dory is inspiring a wave of interest in a new, more expensive breed: The blue tang, which is the kind of fish the movie's bubbly yet scatterbrained namesake is.
They cost $35 to $45 each and are available only at certain shops specialising in marine fish.
Some retailers here report an increase in sales as high as three- fold. But others say these are early days yet, as the film was released in Singapore only on June 16.
But along with the breed's popularity comes a concern: Animal welfare groups worry that fickle owners may eventually neglect or abandon their pets - which was what happened to the clownfish in 2003.
I will look at the customer and size him up to see if he’s a serious buyer with the proper knowledge and equipment.
MR HENRY KO of MarineLife Aquarium on doing his due diligence when assessing buyers who are interested in the blue tang fish
Mr Steve Yeong, 39, owner of Aquamarin, a distributor in Yio Chu Kang Road, says blue tang sales shot up from about 100 to 300 the week the movie was released.
Half of the fish was sold to smaller retailers, while the rest went to direct customers, he adds.
Over at retailer and distributor Fresh 'N' Marine Aquarium in MacPherson Lane, there has been a 10 per cent increase in blue tang sales this month, says owner Edmund Lim, 47.
Other shops say sales remain relatively constant.
Mr Victor Tan, 39, owner of Iwarna Aquafarm, an importer, wholesaler and retailer in Pasir Ris Drive, says: "There hasn't been much change. Blue tangs have always been a popular fish to buy because of their beautiful colour."
Some say that the spike in sales of blue tangs will not be as dramatic as clownfish because of the heftier price tag.
Mr Henry Ko, 63, owner of MarineLife Aquarium in Clementi, says: "Even if there is any increase in demand, it would not be the way Finding Nemo took the world by storm."
Blue tangs are more expensive than clownfish because they cannot be bred in captivity. They are found in the Indian and Pacific Oceans.
Animal welfare groups have been quick to discourage people from buying blue tangs.
"In their excitement, people may not realise that it takes a lot of time, effort and cost to keep an animal happy and healthy," says Dr Jaipal Singh Gill, executive director of the Society for the Prevention of Cruelty to Animals.
The blue tang can grow up to 30cm long and requires at least a 90cm-long tank, water at the right salinity level, a filtration system that maintains water temperature at between 26 to 28 deg C, as well as lighting, sand and rocks to mimic the fish's natural reef habitat.
"They are not a beginner's fish," says Mr Joseph Tan, 46, chairman of the Marine Aquarist Society (Singapore). He adds that blue tangs are also susceptible to parasites that cause white spots.
Animal welfare groups also emphasise that the onus is on shop owners to be responsible sellers.
Mr Ko of MarineLife Aquarium says he does his due diligence.
"I will look at the customer and size him up to see if he's a serious buyer with the proper knowledge and equipment."
Instead of buying fish, deputy chief executive Anbarasi Boopal of non-profit Acres (Animal Concerns Research & Education Society) suggests volunteering with Singapore wildlife protection groups for coastal clean-ups.
"This will go a long way for the blue tangs and clownfish in the wild, where they truly belong," says the 33-year-old.
•Additional reporting by Felicia Choo