• Source: Copyright David Upton

    Link: www.stingrayuk.co.uk

  • Source: copyright www.jjphoto.dk

  • Source: copyright www.jjphoto.dk

  • Source: copyright www.jjphoto.dk

Potamotrygon falkneri (mechacai)

A rarely imported ray which is very pretty. These fish are for specialists.


Fish information (behaviour and breeding):

Stingrays are not aggressive fish, but they will eat fish that are smaller than they are. Care should therefore be taken when deciding on the tank occupants. They are not particularly territorial and can therefore be kept with their own kind.

The following article has been provided by David Upton and is a general summary of how to keep Rays.

1. Research

Don’t just rush out and buy a ray on impulse. Find as much information that you can relating to the care of stingrays. First of all buy a copy of the Stingray Bible (Freshwater Stingrays from South America) a book by Dr. Richard Ross published by Aqualog. This book contains all the information that you will require to properly care for your ray. Including information regarding the danger that they provide because of the venomous sting they carry on their tail.

2. Commitment

Ensure that you have the time/commitment that these demanding fish require. If cared for correctly they may live for up to 20 Years & most of them grow to over 18” diameter.

3. Tank setup

Buy/setup the correct size of aquarium. A minimum tank size for even small Teacup sized rays would ideally be 75 gallons. The larger the tank the happier the ray. Substrate is a matter of preference either bare bottom or sand (non silica) or smooth fine gravel. Lighting is also a matter of preference; a single florescent tube is more than adequate. One must have item though is a heater guard because rays burn very easily. Tank decorations/ornaments are also optional although any item that is to be included in the tank must be smooth & free from any sharp edges that may damage them.

4. Filtration

Ensure that you provide the correct filtration. Always buy a filter unit that has a capacity that is far greater than the tank it is to be used with. Rays eat a lot and so produce a large amount of waste. Because of the amount of waste rays produce it is vital that your aquarium is fully cycled. Also use a filter/power head that will provide a good flow rate through the aquarium. Rays enjoy living in fast moving well-aerated water.

5. Water quality

A basic guide to the water quality that most rays require is as follows: Newly acquired rays require a pH range between 6.5 – 7.0, but once acclimatised most rays can survive within a pH range of 6.0 – 8.5. The main thing is to ensure that the pH stays at a constant level. Rays are very intolerant of fluctuating pH levels. Ammonia – 0 ppm, Nitrite – 0 ppm, Nitrate 5 – 10 ppm. In order to keep the water parameters at these desired levels large weekly/bi-weekly water changes must be carried out religiously. Temperature – 75-80 degrees Fahrenheit.

6. Feeding

Rays will readily eat a wide variety of foods once acclimatised. Suitable foods are as follows: Blood/black worms both live & frozen, Live Earthworms Frozen Krill, Live Ghost/River shrimp Whitebait, Raw Prawns, Pieces of fresh cut fish, Cockles/Mussels & Live Feeder fish. Live bloodworms & Earthworms are a good starter food for a newly acquired ray.

7. Tank mates

As a general rule any fish that will fit into a ray’s mouth will be eaten. Rays are fragile sensitive fish so you must choose any tank mates carefully to avoid adding an aggressive fish that my kill or upset your ray. Newly acquired rays are best kept alone until they adjust to their new surroundings & begin to eat & gain weight.

8. Choosing the correct type of ray.

The cheaper more commonly seen rays generally referred to, as Teacup rays are unfortunately not really suitable for the novice ray keeper. Although it is wise not to purchase any ray that is under 6” diameter. Small rays are very delicate & unless you have experience in their husbandry they are very difficult to keep alive. The rays generally referred to, as Teacups are usually either Potamotrygon Histrix or Reticulata. Although they are both very attractive rays & normally available at very affordable prices they are very difficult to keep. For a first ray I would recommend a Potamotrygon Motoro or Leopoldi. Both of these rays are very hardy & relatively easy to care for. They both cost more than you would pay for a Teacup but it will be money well spent because they are far more tolerant of water parameters etc.

9. Buying a ray

Never buy a ray that will not eat. A healthy Stingray will never refuse food. Ask the supplier to let you see the ray feed. A good LFS/Supplier should always be prepared to do this. Look for signs that the ray is healthy: A healthy ray should always be active & have a nice fat tail with no sign of the protruding pelvic bones showing (2 small triangular shaped bones, one either side of the tail at its base where it meets the disc) or a hollow dent in its forehead.

10. Acclimatising your new ray

Once you have bought your new ray & hurried home don’t rush & pop it into its new home like you would with a regular fish say after you have floated the bag in the tank for 15 minutes. Rays are very sensitive to changes in water chemistry. Because of this it is essential that you slowly adjust the water that the ray came in to suit the water in your tank. The easiest way is to first remove about ½ of the water out of the bag the ray is in & then connect an airline to your existing aquarium to use as a siphon & use a clamp to reduce the water flow to a steady drip. Then slowly add the existing tank water into the bag. Once you have replaced slightly more water in the bag than you have taken out you are ready to put the ray into its new home. Also leave the lights off for the first few days to allow the ray to adjust to its new surroundings.





These fish are vene

Family Group: Livebearers
Distribution Parana, Paraguay basin
Temperature 26-28C
Size Reaches a maximum diameter of around 20 inches
Water Parameters Soft and slightly acidic conditions are required
Water PH 6.0-6.7

Useful sources of information:

An excellent website devoted to Stingrays can be found at www.StingrayUK.co.uk. The site has been developed and maintained by David Upton who has an extensive knowledge of Rays and has kindly provided Tropicalfishfinder with the top photograph.


Shop stock

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