Brick hifin swordtail.
Although it is true that the hifin characteristic must be present
in one parent for a fish to have a hifin dorsal, these branching
characteristics can be inherited from a normally finned fish. So
selecting a low-finned parent whose dorsal rays tend to branch
can sometimes yield a better, fuller dorsal than breeding two hifin
parents. Dr. Roy Levine demonstrated this in a series of articles
for the American Livebearer Association (ALA) in which he bred
hifin swordtails to other species of swordtail and platies, some with
spectacular results (Levine, 2008). I myself have crossed lyretail
swordtails with X. nezahualcoyotl, which is an uncommon wild
species of swordtail from northern Mexico, slightly different from
the petshop swordtail X. hellerii. Such hybridizations, although in
their infancy, may be the wave of the future for hifin and other
Because the hifin, lyretail, and pintail/brushtail genes are all
dominant, it is impossible to get a fancy-finned fish from two plain-finned parents, no matter what their backgrounds are. A female
plain-finned fish will only produce fancy-finned offspring if she
is mated to a fancy-finned male. Beware of breeders who advertise
fish with the “hifin genotype.” Genotype refers to the genetic
makeup of an organism, which may or may not have visible results.
A fish can only have the hifin genotype if it itself has a hifin. The
modifiers—genes that cause the rays of the dorsal to branch—can
certainly be inherited from normal-finned parents, but not the
fancy-fin gene itself.
A Third and Final
Debbie Graham Roy Levine
Although the hifin and lyretail traits both originated in America,
the final fancy-fin modification has its beginning in the tanks of
German aquarist Helmut Stallknecht (Harro Hieronimus, pers.
Black hifin; Dr. Roy Levine showed that crossing a hifinned fish with comm.). Called the pinselschwanz in German, it is called the
a normal-finned fish that has many branching rays in the dorsal fin
plumetail, brushtail, or pintail in English. These all refer to the
produces a broader and fuller hifin in some of the offspring.
same trait—the lengthening of the middle rays of the caudal fin,
as well as a slight lengthening of the pectoral fin, and possibly the
anal fin. However, some breeders (Darrell Mefford of Louisville,
Kentucky, for example) refer to a brushtail as a better specimen
with a lengthier, broader caudal appendage. In my experience,
the appendage becomes brushier as the fish ages anyway. On the
other hand, German aquarists seem to prefer a sharp tip (Harro
Hieronimus, pers. comm.). To each his own.
This trait involves a lengthening of the middle rays of the
caudal fin, along with a slight lengthening of the pectoral (side)
fins (Hieronimus, 2001). Just like the first two traits, this gene
is dominant, which means that if either parent of a brood of fish
carries a plumetail gene, about 50 percent of the offspring will be
plumetail. There are, however, a couple of things that make this
trait much easier to work with than the previous traits. In the
first place, both the hifin and lyretail traits are not apparent on
a baby fish. All of the youngsters appear to be normally finned
at birth, and they do not display the fancy fin traits until about
Combining the lyretail and plumetail traits produces a fish some four to six weeks of age. Not the plumetail! Baby plumetails
breeders call a crowntail.
display the plumetail trait at birth. This means that the sharp-eyed breeder can examine the offspring as soon as they are born
and remove the non-plumetail babies immediately, saving time
and energy. Also, neither of the hammers mentioned previously
affect the plumetails—the plumetail gene is not lethal, nor are the
males incapable of breeding. Thus, broods that consist entirely of
plumetails are possible—even common.
while branches in the ends of the dorsal fins yield a broader, more
spectacular dorsal. Because variatus platies normally have a large
number of branches in the dorsal, crosses with variatus platies
yield such broad-spreading dorsals. The secret of the delta topsail
platy variatus is thus revealed!