The discovery of contact feeding in discus fry was a breakthrough for discus breeders of the
time, who had difficulty feeding the fry in the absence of their parents.
their fry to feed off their body slime, the
production of which increased dramatically
coincident with spawning.
I am relatively sure that other breeders
achieved success in this very same way,
but to my knowledge no record of their
accomplishment, prior to Wolfsheimer’s
article, exists in the American aquarium
hobby literature. In fact, Wolfsheimer
himself notes in his 1957 article that his
eight young specimens/breeding stock were
originally bred by Lois Saphian of St. Louis,
Missouri, and that “her own story appeared
last year in this magazine.” However, she
nowhere mentions this parental behavior in
her article. (Given that the going price for
discus at that time was about $350 per pair,
the key to breeding success was no doubt
kept a carefully guarded secret among those
who succeeded.) As such, Wolfsheimer’s
1957 article is the first-published landmark
account of contact feeding in discus in
America, though maybe not in the world.
Wolfsheimer (1957) notes that the
newly free-swimming fry went to and hung
on to the sides of both parents, who he
surmised were supplying their protective
slime as a first food. He also describes
the fry transfer from the sides of one of
the parents to the other. After about a
week, the fry first ventured away to eat
rotifers and brine shrimp nauplii. Indeed,
the article is accompanied by a photo of
newly free-swimming fry hanging from
the parent’s side, and a second photo of
clearly more advanced fry—possibly two
to three weeks old by size—nipping off
slime. Wolfsheimer reports that just in
advance of the spawning, the prospective
parents “seem to acquire an extra-heavy
coating of this protective slime. When light
reflects off them as they turn into a certain
position, their sides seem to be covered
almost frost-like in appearance. Possibly
certain estrogen hormones are stimulated
and react to over-produce during these pre-spawning periods.”
The popular account that appears in the
1960 National Geographic features several
more photos of discus contact feeding, and
one incredible photo showing young whose
size suggests they may be as much as four
to five weeks old, being transferred from
the side of one parent to the other.
In this article, Wolfsheimer cites the
work of Hildemann (1959) who had, by
this time, proven that spawning discus do
indeed demonstrate hypertrophy of their
lateral epidermal mucus gland cells and
secretions, and that the parents do indeed
feed their young with it. In contrast, the
British aquarists R. and G. Skipper (1956–
1957) in England wrote a series of articles
for the magazine Water Life, documenting
their eventual success in breeding and
rearing discus babies and describing
fry hanging/feeding behavior, but they
suggested it was the microorganisms living
on the body slime—not the slime itself—
that was feeding the youngsters.
Additionally, noted American
ichthyologist Myron Gordon published
another popular account of Wolfsheimer’s
observations, including many of his photos
titled “The Surprising Story of Hitch-hiking
Discus Babies,” which appeared in 1957 in
the journal Animal Kingdom.
Next month, in the second installment of
this column, I will describe how Hildemann
(1959) cleverly proved his “mucus ingestion
hypothesis” and nailed down the biology of
contact feeding in cichlids.
Au, Dick. 1998. Back to Nature: Guide to Discus. Aqualog.
Germany. 128 pp.
Gordon, Myron. 1957. “The Surprising Story of Hitch-hiking Discus Babies.” Animal Kingdom: Bulletin of the
New York Zoological Society 60:170–174.
Hildemann, W. H. 1959. “A Cichlid Fish, Symphysodon
discus, With Unique Nurture Habits.” The American
Naturalist 93(868): 27–34.
Skipper, R., and G. Skipper. 1956. “More news about the
British-bred Pompadours.” Water Life 11:267–268.
Skipper, R., and G. Skipper. 1956. “Pompadours successfully bred in Britain.” Water Life 11:126–129.
Skipper, R., and G. Skipper. 1957. “Those British-bred
Pompadours—the story completed.” Water Life
Wolfsheimer, Gene. 1957. “Discus Spawn... Again.” The
Aquarium 26( 1): 3–5.
Wolfsheimer, Gene. 1960. “The Secret of the Discus
Fish.” National Geographic