Note from Aquarticles: This species has also
variously been called ansorgii and ansorgeii.
Ctenopoma ansorgei
by Barry Lynch
from Wet Pet Gazette, Norwalk Aquarium Society
Volume 53 / Issue 1, July-Sept. 2004
Aquarticles
Introduction:
There are approximately 15 species of Ctenopoma, all of which originate in
Africa. Ctenopoma, like bettas and gouramis, are labyrinth fish - meaning they possess an
extra respiratory organ (the "labyrinth") which allows them to supplement their
oxygen in-take by taking oxygen directly from the air. They are also bubble nest
builders/breeders. The Ctenopoma ansorgei (sometimes referred to as the
"Ornate Ctenopoma" - a name which never really caught on) is, in my opinion, the
most distinctive and beautiful of all ctenopoma. Males reach three inches; the females are
considerably smaller. Both sexes have nicely proportioned bodies highlighted by dorsal and
anal fins which evenly extend from head to tail. Depending upon their mood, the basic
coloration can be green, orange or brown or, more usually a combination thereof.
Additionally, there are six vertical broad brown stripes which cross the body and extend
through the dorsal and anal fins. In display mode, the males are especially stunning.
Background:
Many years ago, I was thumbing through the pages of my first tropical fish book - probably
an Innes book - when I came across a picture of a Ctenopoma ansorgei. I remember
thinking at the time: "Why don't they ever have beautiful fish like this in the pet
store?" My request for some from the local pet store proprietor was greeted by a
blank stare. Through the years, many beautiful fish and beautifully developed varieties
have been introduced to the hobby - cardinal tetras, killies, betas, discus and various
helleri swordtails to name a few. Nevertheless, I'd periodically return to the question:
"Where is the Ctenopoma ansorgei?"
Early last spring, I was conversing with Joe Mulvey at the House of Fins on various
matters. We got to talking about our dream fish - the fish we always wanted but never had.
Of course, I mentioned the Ctenopoma ansorgei. To my surprise, Joe indicated the
fish were occasionally available at the wholesaler. A week later Joe called with the news
that he'd found ten in a small tank at the wholesaler and had picked up six for me - four
males and two females. I immediately raced over to the store to pick them up. I was not
disappointed. Even in the plastic bag, their distinctive markings readily showed.
Aquarium Set-Up:
I felt a 20 gallon long tank would provide plenty of space. Having read the water they
come from is warm, slightly acidic and often oxygen-poor, I decided to mimic these
conditions. The temperature was maintained at 80 degrees; the pH at 6.8. Minimal aeration
was provided by one small sponge filter. In addition to some gravel and several artificial
plants, the tank contained quite a bit of Java moss and water sprite. Although the fish
seemed comfortable in these surroundings, the fish were rarely visible. A week later, I
introduced some adult guppies as dither fish. This worked beautifully as, within an hour,
the ctenopoma were out and about.
Nutrition:
Ctenopoma readily take both live and frozen food. Mine have thrived on a regimen of frozen
bloodworms in the morning and either frozen or live brine shrimp in the evening. The
ctenopoma also supplement their diet by stalking and feasting on the fry produced by four
robust female guppies.
Note: Forget flake food. The first time I introduced flake food, a number tested it and
immediately spat it out. Thereafter the flake food was ignored. On the other hand,
although I've never tried it, based upon my experience with a Ctenopoma acutirostre
(which thrives on freeze-dried krill), they probably would take freeze-dried foods.
Breeding:
One evening about a month after getting the fish, I observed that all four males were in
display mode. Their coloration was brilliant. It appeared they were all displaying to one
egg-laden female. The next morning I set up a 10 gallon breeding tank (similar conditions
to the 20 gallon except the pH was a more acidic 6.5) and moved in the female and a
randomly selected male.
Within a day, the male had commenced construction of a bubble nest. His efforts, at
first seemed haphazard - i.e. a few bubbles were scattered here and there throughout the
water sprite. He ultimately settled on a site in a rear corner of the tank. Unfortunately,
the location made the nest very difficult to view. Regretfully, I also missed the spawning
activity. My first indication that spawning had occurred was the discovery three days
later that the male had driven the female to the opposite corner of the tank. According to
the literature, this meant they had spawned and that the male was now protecting the nest
from all intruders to include the female. I immediately removed the female and left the
male to guard the nest and hopefully some fry.
The next day (the fifth following introduction of the ctenopoma to the tank) I saw my
first baby. It was swimming erratically - suggesting to me that it hadn't fully extricated
itself from the egg. While I was watching, the male swooped in and ate it. It is my
understanding the male generally protects the fry. Perhaps the male recognized a defective
baby. In any event, I chose not to take any chances and removed the male.
Ctenopoma Fry:
Over the next several days I would periodically sit in front of the tank hoping to catch a
glimpse of ctenopoma fry - to no avail. Although frustrated, I was not particularly
concerned given the number of potential hiding places (gravel, Java moss, water sprite,
etc.). I started adding some baby brine shrimp to supplement whatever infusoria was in the
tank. After a week of feeding invisible fish (the only baby I'd seen was the one eaten by
the father), my patience ran out. I had to know if I had babies.
In essence, this meant tearing the tank down - a process that took over three hours.
(Removing the gravel without damaging any babies that might be there took the longest.)
The effort was worth it. In the end, I moved 36 babies (two tiny dots for eyes and small
transparent bodies) to a gravel-free 5 gallon tank containing a small sponge filter, Java
moss and water sprite.
Over the next two weeks, the babies still tended to be invisible. Occasionally, when I
approached the tank, I'd catch a glimpse of one or more dive-bombing into the Java moss.
By the time I reached the tank, they'd disappeared. I finally tired of this and resolved
to wait them out. After about five minutes of sitting in front of the tank with my nose
almost pressed against the glass, a tiny head emerged from the Java moss and then another
and then another. The next thing I knew there were 30 plus sets of eyes fixedly staring at
me from the Java moss. There was no movement whatsoever. They were as curious about me as
I was of them. After another five minutes, I slowly got up and departed - feeling that we
had finally introduced ourselves. It may be coincidence; but, from that point on, the fish
openly fed and swam in front of me.
As the fry grew, one thing became very noticeable - individual growth rates varied
tremendously. At one point in time, the largest ones were ten to fifteen times larger than
the smallest ones! I became alarmed that I had a sizable bunch of runts. Fortunately, over
time the size differential disappeared. I suspect but cannot state with certainty that the
larger ones matured into adult males and the smaller ones into the smaller females.
The 20 gallon tank which originally housed the six adults (they together with ten of
their young were sold at the NAS October auction) has served as the grow-out tank for the
remaining ctenopoma. The fry proved very hardy - 35 of the original 36 have survived into
adulthood. At eight months, the young are larger than the six adults were when auctioned.
The remaining 25 together with their guppy companions seem at home in their 20 gallon
tank. There has not, however, been any bubble nest building. This suggests they may be too
crowded for some normal activities. Over the next few months, I hope to find some new
homes for many of the ctenopoma.
Behavior:
I have discussed ansorgei with several people who have maintained them. Three terms which
keep coming up are "inactive","seclusive" and "aggressive."
(i) Inactive: There is some truth to this. Ctenopoma do not swim aimlessly
about. Following each feeding, they retire to secluded parts of the tank to digest their
meal in privacy. After about an hour they re-emerge. Some will rest at or near the bottom.
Some will hover/glide head down (positioned like a headstander) in a stalking fashion.
These may periodically display. A few will wander through the water sprite perhaps looking
for possible bubble nest sites. At all times, the ctenopoma present an appearance of
extreme alertness. Of course, a guppy producing babies will galvanize the activity. An
egg-laden female will do the same.
(ii) Seclusive: As indicated earlier, I too initially experienced seclusivity.
But, the use of guppy dither fish eliminated this situation both with the adults and later
with the juveniles as they approached adulthood. On one occasion, thinking the young
adults no longer required the dither fish, I removed the guppies. The ctenopoma
immediately disappeared and remained that way (except at mealtime) for several days. I
relented and returned the guppies. Within two hours, the ctenopoma were once again active
throughout the tank. It appears dither fish are essential if you really want to enjoy your
ctenopoma.
(iii) Aggressive: Quite frankly, I simply haven't seen aggressive behavior. In
the nine months I've maintained them, I've seen no fights and not one nipped fin. (Note:
When I first introduced guppies, I foolishly used double swordtails. Like many fish, the
ctenopoma were unable to resist the swords. I replaced the double swordtails with regular
guppies and have experienced no further fin nipping.) Even when the four males were vying
for the attention of the egg-laden female, they merely displayed and did not fight.
I suppose their feeding behavior appears aggressive but it proves harmless. When the
food is introduced, the fish do not amble up and leisurely swallow. Rather, most (both
males and females) immediately display and attack the food. Each fish will swoop in, grab
a bloodworm or shrimp, swoop out and then swoop back in for another. Seeing 25 ctenopoma
do this at the same time is a sight to behold.
Ansorgei as Community Tank Fish:
I haven't tried it so anything I say here is pure supposition. At one time, I considered
adding a few to a 30 gallon community tank but rejected the idea due to the presence of
dwarf honey gourami. I feared competition for bubble nest sites which the gourami would
clearly lose. However, based upon the good experience with the guppy dither fish, I
believe the ctenopoma would be fine in an appropriate community tank. Such a tank should
not have fish small enough to be swallowed whole. Nor should it have larger aggressive
fish which might induce the ctenopoma into permanent hiding.
Ansorgei as Show Fish:
I decided to enter three of the adults in the NAS October fish show - a male in the
"Anabantoid Other" class and a pair in the "Miscellaneous Pairs"
class. Neither entry placed. This did not come as a great surprise. I had had some concern
regarding their transition from a highly planted to a bare tank. What they did was simply
sit on the bottom with muted color. I had been advised by a friend with considerable show
experience to acclimate the fish by isolating them in bare tanks for 30 days prior to the
show. While I'm sure this would have helped, it was not something I was willing to do.
What I should have done was put some water sprite into the show tanks. (This is
permissible under Show rules.) It undoubtedly would have made them feel more at home. And,
what a sight it would have been if the male had commenced building a bubble nest and
started displaying for the female! Whatever. While the ctenopoma did nothing to impress
the judges, they certainly caught the attention of participants at the ensuing NAS
auction. I happily used the proceeds to purchase some emperor tetras and Limia vittata
- both of which, I'm pleased to say have produced nice healthy fry.
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