You are right. Your guess is correct and for more details you can contact with Dr. Ramin in our Institute (IFRO) with Telephone No. 021 44580593.
Meanwhile, Amphiprion polymnus, also known as the saddleback clownfish or yellowfin anemonefish, is a Marine fish belonging to the family Pomacentridae which gathers clownfishes and damselfishes.
The Saddleback clownfish is a small sized fish which grows up to 13 centimeters (5.1 in). Its body has a stock appearance, oval shape, compressed laterally and with a round profile.
This orange caudal stripe color is different from the common pattern for polymnus. This fish is from the "polymnus complex", but could be another specie. Unfortunately a aquarists web site called rareclownfish.com is out of the web, their we could confirm. Geographic speciation is very common for clownfishes. Were this specimen was collected?
Color is highly variable in this Family, so it is not surprising that this specimen is slightly different than what may be expected. John Randal posted a similar picture on FishBase (http://www.fishbase.de/Photos/PicturesSummary.php?StartRow=1&ID=8086&what=species&TotRec=6). I know that FishBase has many errors, but Randal is a trusted source. His specimen came from Indonesia.