This article was updated with a statement from PUB.
The ocellate river stingray, also known as the motoro stingray, is not native to Singapore.
All the same, one such stingray was spotted giving birth right here in one of our local reservoirs.
Distinguished by its black-edged, orange-yellow eye spots that almost resemble eyes, the species is, in fact, endemic to South America, and can be normally only found in places like the Amazon basin.
It possesses a venomous tail, and an incredibly sensitive electroreceptor system known as Ampullae of Lorenzini, also found in sharks, that picks up electric currents and fields released by hidden prey.
Premature pups
A Facebook user by the name of Rovena Chow posted a video of an ocellate river stingray giving birth to a bunch of pups in a local reservoir on Apr. 6.
The stingray's pups appeared translucent, pink, and quite small:
Photo via Rovena Chow
Chow described it as an "incredible moment", and other users expressed their awe in the comments section.
However, veteran nature guide and wildlife specialist Ivan Kwan commented on the post, noting that the pups were premature, based on their colouration.
He also noted that the species has come to become established in our reservoirs and rivers due to abandonment.
Screenshot via Facebook
Ivan also shared a video of a Motoro ray giving birth, showing what newborn pups typically look like if carried to term.
Unlike the translucent pups seen in Chow's video, they look almost like smaller versions of the mother stingray.
Screenshot from Moose MJ / YouTube
Stress from being caught
Female stingrays typically give birth once a year to about two to six pups at a time. They are also ovoviviparous, with the young hatching from eggs held within the female stingray.
Some Facebook users speculated that the premature births may have been the result of illegal fishing. One user suggested:
Screenshot via Facebook
"Capture-induced parturition", according to this research paper, refers to a phenomenon whereby sharks and rays tend to give birth or abort their young upon stress from being captured.
The study also noted that recreational fishing can cause stress-induced abortions and premature births in stingrays.
Aquatic pet trade
Stingrays are, in fact, a fairly common sight in our local reservoirs.
A paper published by researchers at the National University of Singapore (NUS) details how the ocellate river stingray is an invasive species that came to be established in local water bodies thanks to "being popular worldwide as ornamentals in the aquarium trade".
According to an article by The Straits Times (ST), these rays are seen as "status symbols", with expensive specimens sometimes priced as high as S$200,000.
The trade has, however, led to stingrays being released by irresponsible pet owners into local water bodies.
The NUS researchers also pointed out that the stingrays, given their venomous stingers, actually can do "serious harm" to humans. Thus, they constitute a "safety hazard" if permanently established in our reservoirs and rivers.
As an invasive species, they also can cause harm to the local environment.
They can crowd out native freshwater species, and compete with them for resources.
A Singaporean man was charged in 2017 for releasing three of these venomous rays into the Lower Seletar Reservoir.
PUB will remove such stingrays if spotted
PUB told Mothership in an Apr. 12 statement that motoro stingrays like the one seen here are likely released by someone into the reservoir.
"Such release risks disrupting the aquatic ecosystem and may also pose a risk to users of our reservoirs," PUB said.
PUB added that it conducts daily patrols at the reservoirs and will remove such stingrays if spotted.
Under the Public Utilities (Reservoirs, Catchment Areas and Waterway) Regulations, it is illegal to release animals into reservoirs and waterways and offenders may be fined up to S$3,000.
Members of the public should call the PUB hotline at 1800-2255-782 (1800-CALL-PUB), if they spot any person releasing animals into waterbodies.
Top photo from Rovena Chow/Facebook