The polka dot stingrays would swim towards him, flapping their discs like flamenco dancers, and gliding gracefully like butterflies. Watching them at feeding time makes for some of the happiest moments for private investor and businessman Lim Ngeok Kong, 58.

“As they grow, they morph and more white dots will appear on their body,” said Malaysia-born Lim, who became a Singapore citizen in 2013.

“By the end of 2011, I had accumulated 40 Black Diamond (BD) stingrays,” he said, adding that he had spent a small fortune on them.

He bought them mostly online from suppliers in Taiwan, the Netherlands, Germany, Thailand and Singapore, where the import of fish is quite easy and shipping is door-to-door.

His relationship with freshwater stingrays was “not love at first sight”. He had no intention to rear them, initially. (Also read: You don’t want to mess with stingrays).

But, eventually, Lim fell in love with stingrays and began to buy more beautiful ones.

In May 2010, he bought a pair of P13 rays for his daughter. She found the rays to be “very cute” and asked her father to buy them as her birthday present, during a fish farm visit.

When he enquired about the price of the rays, he was shocked.

He said: “I paid S$2,600 (RM7,682) for a pair of 10cm diameter black stingrays with white polka dots known as P13.” This species of freshwater stingrays is known as Potamotrygon Leopoldi P13; they are endemic to the Xingu River basin in Brazil.

Three months later, he “inherited” them when she left for Perth to further her studies.

When he took over his daughter’s stingrays, he began his research into the care of these creatures.

Lim prefers to keep his Black Diamond rays in a pond, rather than in a tank, as this allows a better view of the gorgeous polka dotted rays.

He said there’s still very little information about these rays on the Internet. Most hobbyists he knows do their best to rear them.

“The female ray which my daughter named Big Mama bred twice and the pups were sold. I also sold all the pups bred by my rays. I don’t want the hassle of keeping them as they need a lot of attention,” he said.

New additions

After three years, some females gave birth to pups of 7.6cm to 10cm in diameter. Typically, they give birth to four to six pups at a time.

From 2013 to 2016, Lim sold the pups through a middleman as he did not intend to grow his collection.

The proceeds from the sales were used for the upkeep of the existing rays (for food, equipment, tanks, electricity and water). Maintaining the rays is very costly – food alone costs about S$1,000 (RM2,947) monthly. The estimated expenditure is about S$2,000 (RM5,894) per month to maintain all 40 rays. Many of his rays are mature and the females are ready to breed.

Lim explained: “I’m not very keen to breed the rays because during mating, for reasons unknown, the male will attack and bite off big parts of the disc of the female. This cause the females to lose some of their white spots and good looks.”

To keep all his rays, Lim converted his fish pond into a stingray pond, and gave away the fish to friends and neighbours. He also has seven glass tanks (measuring 1.8m x 0.9m x 0.7m) in various parts of his three-and-a-half storey house in Upper Bukit Timah, Singapore. Typically, it is recommended to rear a maximum of four rays in a tank as they will grow to adult size of about 56cm in diameter in about two years.

Lim’s family was not very happy with his newfound hobby, especially when he cluttered the house with everything “fish”. However, they put up with him when they saw how happy he was keeping the rays.

He continued his research online almost daily and began to realise that keeping rays is indeed a very demanding hobby. It requires many pieces of equipment and a lot of time to ensure that water parameters are good (pH value, fresh water). Also, fresh prawns are their preferred food. His 40 stingrays typically consume 20kg of prawns every 10 days. It takes a lot of time to prepare all the prawns to feed the various sizes of rays.

Lim also has to scrub the glass tanks once a week, for better viewing. Nevertheless, he gets much satisfaction and pleasure seeing them swim around in the tanks. They grow more beautiful in the adult stage and have more interesting spots emerging on their backs.

Daily, after Lim returns from work, all his time would be spent admiring and caring for his rays – sometimes until midnight – and meddling with a malfunctioning gas pump or adjusting the pH value of the water.

Ornamental fishes

As a boy, Lim liked keeping ornamental fish. At 15, he had 15 fish tanks (0.6m x 0.3m x 0.4m) and a pond (1.5m x 2.5m) to keep them. He went to the rivers with his fish-loving buddies to catch more fish and prawns.

“We would keep the nicer fish and use the others as food for bigger fish. Those were the happy days,” he beamed.

In 1980, he gave up his hobby when he went to study at the National University of Singapore.

He graduated with an engineering degree in 1984.

In 2008, when he rebuilt his present house in Singapore, he started to rear fish again. He even built a fish pond as part of the landscape for his house. He kept common fish like barbs, loaches and goldfish which he could easily buy from the local fish shops.

The spotting around the rim is one of the characteristics of the P13 Black Diamond ray. Other key features are the colour black and the contrasting white spots. Different rays have different spotting patterns.

With the Internet and the help of a pond specialist, he gained more knowledge in fish-rearing. He knew fish’s faeces is harmful and will kill the fish if too much accumulate in the tank. So he built a separate filter tank to remove or convert the harmful ammonia from the faeces. After that, his fish had a very low death rate.

In June last year, after many tiring years of keeping the rays, Lim decided to only keep rays in his pond and sell off those in the tanks and tidy up the house.

“I managed to sell them at a good price and recouped my initial investment. Now, I only have 10 mature stingrays in my pond, and one tank. This is to separate the males from the females to prevent breeding. I’m into keeping rays as a hobby and not for money so I choose not to breed them,” Lim said.

“I enjoy my rays better now, as it is more manageable and, at the same time, I free up the space in my house for my other hobby – collecting sculptures.”

Good ray hobbyist

When he had 40 rays, Lim was quite well known among the ray-keeping community. His visitors are amazed at the rays and, for many, it is their first time seeing such beautiful fish.

Lim said: “The ray-keeping community regards me as a good stingray hobbyist because I can rear them from pups to adult rays with only one death out of 40. This is very rare. A lot of fish hobbyists try to keep Black Diamonds but most of them die within a year or so. I guess these hobbyists either do not know the requirements of the water parameters or are simply negligent.”

When handling rays, he cautions: “Don’t put your hand in the water!”

He explained: “This is because all stingrays will sting when provoked. I read on the Internet that the sting is so painful that these stingrays are also known as ‘I-wish-I-were-dead’ fish.”