HIFIN
Features
This mutation causes the dorsal fin (the fin on top) to extend in length. Currently breeders breed for additional height and length. Males often display more impressive fins than females, and the length of the dorsal fin increases as the fish ages.
Nomenclature
This trait was originally introduced to the hobby in the early ’60s, found on fancy X. hellerii. It was sold under the name “Simpson Swordtail”, after its discoverers. Because platys lack a swordtail, the name “Simpson Swordtail” was dropped in favor of the more inclusive name “Hifin” (alternatively spelled “Hi-Fin”). “Sailfin” is another market term that emerged recently, but these are merely hifins with slightly different modifiers, and “topsail” platys are similarly just another synonym.
History
This trait was originally introduced to the hobby on swordtails in the early ’60s under the name “Simpson Swordtail”. It has been bred into both maculatus, variatus, and in a few scattered examples, X. montezumae. Due to the lack of a sword I imagine, the name “Simpson Swordtail” was dropped into the more descriptive “Hi-Fin” platy, swordtail, etc. See "One Little Fish and Thelma L. Simpson" for an account of the trait's discovery.
Genetics
Although the gene is dominant, a fish cannot be homozygous for Hifin (HH), as two doses of the gene are lethal. In order to produce Hifins, a breeder would need to cross a Hifin (Hh) to another Hifin (Hh), yielding 66% Hifins, or a Hifin (Hh) to a normal fin (hh) yielding 50% Hifins. This implies a true-breeding hifin strain is impossible. However, several strains have been described that yield nearly 100% Hifin offspring!
Availability
Hifin platys and variatus are very common and can be found in most pet stores with poor hifins. Swordtails are less common, but can often be found for sale on Aquabid, where the best examples can go for hefty sums.
This mutation causes the dorsal fin (the fin on top) to extend in length. Currently breeders breed for additional height and length. Males often display more impressive fins than females, and the length of the dorsal fin increases as the fish ages.
Nomenclature
This trait was originally introduced to the hobby in the early ’60s, found on fancy X. hellerii. It was sold under the name “Simpson Swordtail”, after its discoverers. Because platys lack a swordtail, the name “Simpson Swordtail” was dropped in favor of the more inclusive name “Hifin” (alternatively spelled “Hi-Fin”). “Sailfin” is another market term that emerged recently, but these are merely hifins with slightly different modifiers, and “topsail” platys are similarly just another synonym.
History
This trait was originally introduced to the hobby on swordtails in the early ’60s under the name “Simpson Swordtail”. It has been bred into both maculatus, variatus, and in a few scattered examples, X. montezumae. Due to the lack of a sword I imagine, the name “Simpson Swordtail” was dropped into the more descriptive “Hi-Fin” platy, swordtail, etc. See "One Little Fish and Thelma L. Simpson" for an account of the trait's discovery.
Genetics
Although the gene is dominant, a fish cannot be homozygous for Hifin (HH), as two doses of the gene are lethal. In order to produce Hifins, a breeder would need to cross a Hifin (Hh) to another Hifin (Hh), yielding 66% Hifins, or a Hifin (Hh) to a normal fin (hh) yielding 50% Hifins. This implies a true-breeding hifin strain is impossible. However, several strains have been described that yield nearly 100% Hifin offspring!
Availability
Hifin platys and variatus are very common and can be found in most pet stores with poor hifins. Swordtails are less common, but can often be found for sale on Aquabid, where the best examples can go for hefty sums.