They may grow to only 3cm and their general life span is about two years.
One can cost as little as $1 or up to $1,200, depending on the grading scales.
And, you can't eat them.
Keeping them requires the right kind of environment and a set-up that could be quite costly.
Yet these ornamental shrimps are gaining a gradual and steady following, among their admirers are students and working professionals.
A check with several shops indicated that there are many variations of shrimps, from crystal red to yamato, zebra and cherry.
Aquarist Chamber owner Alvin Chan, 35, started out as a hobbyist.
He recalls how the first year in 2007 was a real test as his attempts to keep the shrimps failed.
"No one could guide or teach the proper methods then and it was a year of failure," he says.
At that time, the fad was not catching on yet in Singapore and what few breeders there were, were still in experimenting stage.
Mr Chan says he "started to make progress" after he met a friend from Taiwan, who was willing to guide him.
Aware that there were other hobbyists who faced the same problem, Mr Chan started Aquarist Chamber in December 2013.
He has since expanded from ornamental shrimps to include a section on small- and medium-sized fishes such as wild discus and plecos.
But Mr Chan has not forgotten his initial aim. He says: "I still share my knowledge with other hobbyists to guide them."
That passion is evident from the way he interacts with customers, many of whom have become regulars at his shop in Upper Serangoon Road.
Customers are free to move around and spend hours observing colourful and patterned shrimp without feeling obliged to buy.
Mr Chan says: "Customer service is key and I don't believe in hard-sell. They must fall in love with the shrimps first."
And for an interested novice, Mr Chan says a basic start-up kit at home should include "an average 0.5-metre tank, chiller, canister filtration, soil, bacteria and appropriate minerals", which could cost up to $1,000, excluding the shrimps.
For someone like this reporter, who finds it hard to even keep guppies alive, it is hard to understand the fascination with shrimps - especially when it doesn't sound like a cheap hobby.
Mr Chan says: "One reason the interest is sustained is the sense of achievement when you find you are breeding good shrimps.
"There is also a sense of satisfaction from working through failed breeding attempts to find a solution or improvement to the system."
And the operators are confident the community will grow.
Mr Colin Chin, 31, owner of CRS Haven in Tampines, says: "We are always importing new breeds of shrimps and that keeps the hobbyists engaged."
CRS Haven, which has been specialising in ornamental shrimp since 2007, has recently introduced its own trademark Wondershrimp.
The species are kept in an open self-sustaining ecosystem that may appeal to those looking for shrimps that need less maintenance.
Mr Chin says in jest: "You can go on a holiday for a month, come back and they'd still be alive."
This article was first published on January 18, 2015.
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