Asian Stingray Culture: Selective Hybridization

Within my research of the Potamotrygon, I have come across many fascinating unidentified Stingrays.  Within reason, all potamotrygon should have the ability to hybridize.  Selective Hybridization has been a staple of aquarium fish culture, primarily in Asia, for centuries.  Goldfish and Koi being the first 'developed' strain of aquarium fish, have evolved into hundreds of variations of the common goldfish, Carassius Auratus.

Selective Hybridization of Potamotrygon has already been taking place in Singapore and Thai fish culture for many years.  Before the ban of black stingrays from Brazil, some major breeding facilities had purchased a number of very prized fish stock in order to produce amazing offspring.

The Thai are the pioneers of cross breeding, and the initial thought of cross breeding different types of rays was carried out with a professional approach.  However, Thai culture holds their secrets close to family, and information is vague and sparse.  I have been lucky enough to speak with a few Asian stingray breeders, to provide this info.

In Asia, a new breed called 'Potamotrygon sp. 'SP' is being produced.  'SP', Meaning Special, could be any number of generations of hybridized ray, being referred to strictly by common name.  The owner of the breeding stock would be the only one who knew the genetics of his product. That is only if the person he purchased his breeding stock from, knew the genetics of the fish that produces his product.

After speaking with multiple individuals, I have heard several methods of production of the 'SP' type.  Some breeders prefer to set-up large outdoor ponds, and house a combination of different types of stingrays together and allow nature to 'run it's course.' Introducing new genetics periodically and separating offspring to grow out for selective patterns.

Others, are much more calculated in their endeavors, with a much more scientific nature to their production process.  Using secretive techniques such as growth enhancing gelatinous and pelletized foods and the use of photoperiod timing to accelerate reproduction.  They use isolation tanks and are very specific in which stingrays they wish to cross breed.

With the advances in the study of recessive traits, they have developed a techniques to dictate the desired pattern in the offspring. However, the success rate of a 'morphed' offspring is very low, as only 5-10% of the pups produced will have a sporadic 'SP' pattern like the cross bred rays to the column on the left.  Those rays are all Leopoldi x Motoro.  The other offspring produced will take on the traditional trait of one parent. Unwanted offspring are culled and quickly sold to the market.

"CB", a term for cross-breed in Asian breeding culture, is when you cross 2 distinct species, such as Leopoldi and Motoro.  When creating a "CB", the offspring tend to take on the form of one parent, or the other.  Through multiple generations, particular desired traits can become dominate in a strain, such as a marbled or scribbled type pattern.

"HB", a term for hybrid in Asian breeding culture, is when a fish looks like a distinct species, but has a dominate strain effecting its polymorphic coloration and pattern.  An example of "HB" would be a classic looking Leopoldi, with 15% Marble Motoro in it's genetics, to create what looks to be a 'Black Isle' stingray harvested from the wild.  These rays take many more generations to produce, and prices are reflective of this.

They have found that creating a dominate gene with the less abundant black ray species, and breeding them with females of brown rays, is most productive.  The 'brown rays', such as Castexi and Motoro, are much more prolific in their birthing process, and the chances of producing desired offspring is increased with each gestation period.

Many of the Unidentified Potamotrygon you see being sold as captive bred, could quite possibly have mixed genetics.  With the ease of hybridization within the potamotrygon family, it is also very believable that you could purchase an animal harvested from the wild, that does not contain pure genetics.  Until DNA testing is done, and a re-classification of the potamotrygon family is accomplished, we must assume that not all species are 100% true, no matter the point of origin.

-Miles

'Midnight Butterfly' - PDR HB SP (Special Leopoldi Hybrid)

Marble Motoro HB

Henleii SP

Mantilla HB

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