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Anabantoids, the Labyrinth Fishes.
The Labyrinth fishes that we were accustomed
to call "Anabantids" actually fall
into four family groups. It's not really
that confusing. The gouramis are all in the
family Belontiidae, except for their kissing cousins, the Helostomatidae (Kissing Gouramis). But the original "Goramy,"
the edible Giant Gourami that is sometimes
mistakenly bought for aquaria, is one of
the Osphronemidae, along with Spike-Tailed Paradisefish. The
fourth family of Anabantoids are the Anabantidae themselves, like Anabas, the Climbing Perch, which is actually another
food fish, only rarely kept in aquaria. The
widely-distributed Anabantidae include the Bettas and Paradisefish, and
also the African Ctenopoma.
The modern biogeography of the labyrinth
fishes gives clues to where the group evolved.
It's generally agreed in principle that the
distribution of freshwater fishes provides
a clear link between the geological and biotic
evolutionary history of a region, because
the dispersal of fishes depends on direct
connections between river basins, and the
history of basin interconnections reflects
the transformations of regional geology.
The center of Anabantoid species diversity
lies in South-East Asia, ranging from India
to Borneo. The stem-group, the least-specialised
group, from which the other families have
diverged, appears to be the Anabantids, with
Ctenopoma a relict outlying genus, though it is distributed
all over Africa, where different species
are present in every major African watershed,
from the Nile to the Zambezi. So, doesn't
the modern distribution suggest that "primitive"
Anabantids developed in southern Laurasia,
before India came ashore from the south and
crumpled up the Himalayas? and that they
spread as far as Africa all across Iran and
Arabia during much wetter Paleocene-Eocene
climates, before those areas were uplifted,
and long before the Red Sea split open to
make a saltwater barrier?
Raising anabantoid young. The minute anabantoid fry are famously delicate.
At the age of some weeks they may die in
droves. The common explanation is that the
labyrinth organ is developing at that growth
phase, and that the young are especially
susceptible to drafts of cold, dry air. Could
be. A more recent alternative explanation
has a more credible ring to me. It suggests
that the fry are stressed by ammonia/nitrite/nitrate,
which is beginning to build up, the result
of constant feedings in bare-bottomed tanks
that depend on sponge filters for biofiltration.
Could I make a second alternative explanation?
Many adult fish carry a light but sustainable
load of skin and gill flukes, both in the wild and in captivity. Anabantoid
fishes don't rely strongly on their gills,
and may not show acute distress from a moderate
parasite load. Some flukes release eggs that
hatch into ciliate-like larvae. Others release
fully-developed trematodes. Either type of
fluke can be passed through contact from
a parent to the fry. A few flukes may be
of scant concern to a full-grown fish, but
it doesn't take many to overwhelm the developing
fry.
General labyrinth fish links.
First of all, you should check out "Labyrinth Fishes," the web's most informative strictly anabantoid
website, often up-dated by webmaster Philippe
Kerremans, with a unique feature: a search
machine that picks up references to any species
or species group that interests you from
all the newsgroup postings. The site also
offers clickable maps that give you lists
of the anabantoid fishes found in any specific
geographic area. And the links will get you
to the generally less informative websites,
maintained by associations, such as the Anabantoid Association of Britain, which does archive a couple of dozen articles,
with balanced coverage of the Anabantoids,
or, strictly for domesticated fancy show
Bettas, the U.S.-based International Betta Congress.
Betta splendens (Siamese Fighting Fish). Splendens does mean "splendid," just as
you always figured it did. But did you know
that when they were exported to Europe they
were first bred in France, in 1893? The splendiferous
veiltail bettas have been selected over generations,
but the wild form is still found all through
the lower Mekong basin in Thailand and Cambodia.
The stockier, duller-colored strains cultivated
in Thailand for fighting bear little resemblance
to long-finned aquarium strains.
Anyone simply referring to a "Betta"
(ever since the Beta-Max fiasco often mispronounced
"BAY-tuh" but you'd betta say "betta")
usually means one of those spectacular man-made
creations displayed in cramped jam jars at
your LFS. Some "wild-type" bettas
do creep into the market, though; so, if
you agree that a fish with two tails is not
a lot more attractive than a calf with two
heads, you should be glad to know that there
are magnificent wild betta species out there,
real enough and rare enough to lure even
the most fastidious connoisseur. Check out
some of the recent discoveries in this genus,
made in Sarawak and Sabah and other remote
sections of Malaysia during the last decade
or so, and reported in a brief illustrated
article, "The Fighting Fishes of Malaysia,"
hidden deep in the National University of
Singapore's inscrutable website www.science.nus.edu.sg/~webds/fish/fightfsh.htm
Knut Philippi of Hallettsville TX is working
out the kinks of importing from Southeast
Asia many wild species of Betta and Parosphromenus
that you'll never see at the LFS. He's got
photos and the briefest capsule info at his
site, Knut's World of Bettas: http://wildbetta.cjb.net/
Details of breeding bettas are familiar:
you'll find plenty of stuff in the links
that follow. But putting the female with
the male can be a little tricky sometimes,
even when she looks ripe. Al Castro offered
a good trick in Aquarium Fish: he put the female in a glass jar filled
to a half-inch from the top, set into the
male's tank so that the tank water also comes
to within a half-inch of the jar's top. When
she's ready, she'll jump the jar! (The jar
would protect her afterwards.)
Links. There's so much posted on the web about
Bettas There are six Yahoo WebRings
of Betta sites, more even than the WebRings
devoted to Sharks! I scarcely have anything
to add. A good place to start, with
basic information about keeping Bettas and
breeding them, is at the Betta Barracks:
http://www.betta-barracks.ourfamily.com/
Jeffrey Ong, a breeder in Singapore, has
a betta page with all the basics and none
of the cuteness that seems to plague betta
folks: http://www.geocities.com/TheTropics/Lagoon/1517
And Kaycy Ruffer describes breeding Betta splendens at her website. She's posted a fine pic of a black betta.
Colisa chuna (Honey Gourami). It's increasingly hard to find the natural
C. chuna from northern India (Assam) and Bangladesh;
it is replaced at your LFS by its hybrid
with the Dwarf Gourami, called a "Honey
Gourami" or by some other fanciful "uncommon"
name. A "Honey" Gourami, mis-identified
as a "variety" of Dwarf Gourami,
made the cover of Aquarium Fish for Feb. 1994. The genuine C. chuna, is a slightly delicate little beauty whose
males display an intense black throat patch
at breeding time but whose females are convicted
of the capital sin of being less colorful.
The females are different enough that Hamilton
and Buchanan described them as a separate
species in 1822, Colisa sota; the confusion of names remains to this
day.
The best brief illustrated entry on C. chuna is at Aquaworld.
Bob McDonnell's article on breeding C. chuna was at www.e-aquaria.com/honey.html . Dr Peter Gruendler has posted four excellent photos of his C. chuna spawning in a low-tech tank with plenty
of floating plants, where traces of ammonia
and even a little nitrite didn't seem to
make a difference, at pH 7.4. The watchful
male took his brood in his mouth and shifted
them from leaf to leaf.
Newly-free-swimming gourami fry are all extremely
small, so it's not easy to know what to feed
them. A useful 1998 Live-Food Digest thread rating green water, infusoria, microworms
and the biofilm on plants, even artificial
plankton for feeding C. chuna fry is in the Live-Food Digest archive.
Follow the thread through to get all the
good information and the excellent highly-informed
geek flavor.
Colisa labiosa (Thick-lipped gourami). Colisa labiosa and a very closely-related species, C. fasciata, have probably been blurred together into
hybrids for the hobby market. C. fasciata is sometimes quite earnestly called the "Giant
Dwarf Gourami," so if you were to see
some juveniles at the LFS, I guess you might
ask for "a small Giant Dwarf Gourami."
Though you'd be more likely to be seeing
the true Giant Goramy, Osphronemus goramy, featured on "Iron Chef," this
food fish has turned up in the aquarium trade
from time to time and could be given to a
naive friend as a cruel practical joke. But
scope this Goramy obituary!
A selected naturally-occuring variant of
either the real C. labiosa or its hybrid form, is the good-looking
"Sunset Gourami." That fish is
often confused in turn with the "Flame
Gourami," a name that should properly
identify a selected de-striped form of C. lalia . All utterly confusing, eh. Casually mis-identifying
photo captions in the TFH books on Anabantids
have us even more confused.
The "Sunset Gourami" is slightly
smaller than typical wild C. labiosa individuals. It might be a little drab in
the retail store. At home it's a warm pinky
golden brown with an orange-gold edge to
the dorsal and anal fins. The wild labiosa type is striped with pale blue and comes
from the heart of "Colisa country:"
northern India, Bangladesh and Burma. In
both kinds, females are less intensely colored
and plumper in form, and the rear corner
of their dorsal fin is more rounded than
it is on the males.
Spawning activity of C. labiosa was well described by Iggy Tavares in F.A.M.A., Feb. 1999, pp 42ff. He noted typical Colisa
mating action: the male building a bubblenest
in one corner of a planted (with silk plants)
aquarium while the female filled with eggs.
The male courted the female, who took refuge
among the artificial plants. When she was
ready, she came to him— a good point for Colisa marriage brokers to remember— under the
nest. There they did their rolling embrace;
he spat the eggs up into the nest, then chased
her off when she was spent. The fry hatched
after 30 hours and could be seen hanging
from the nest, while the male tended to any
stragglers.
Colisa lalia (Dwarf Gourami). This astonishingly handsome little fish
is so common in Northern India and Bangladesh
that it's been introduced to areas where
it wasn't native, to handle malaria mosquitos.
Escapes from fish farming have established
Dwarf Gouramis in Singapore and the nearby
southern end of the Malay peninsula, and
even in the Baram River of Kalimantan (Borneo),
where you can be sure Mother Nature never
placed it. In northern India, C. lalia take from 8 to 12 months to mature. Larval
fish from the summer spawnings overwinter
and mature by the peak temperatures of May
and June, when they start breeding repeatedly
til the cooling monsoon rains of July and
August dampen their ardor. Take this cue
and you can encourage spawning in the aquarium
by slowly raising water temperatures to about
82oF.
Wiljo Jonsson has a series of truly outstanding
close-focus pix showing Dwarf Gouramis spawning
at his site, among the "Akvariefiskar".
For their size, male Dwarf Gouramis can be
unexpectedly aggressive, especially when
they're in bubble-nesting mood. Ordinarily
there's room for only one fully-colored dominant
male, even in a roomy planted tank. Other
males will be pale and harassed. Mixing color
varieties is unlikely to have an effect on
aggressive behavior. A pair of females, though,
can share the stress of the male's attentions.
Their natural rhythm in native waters also
suggests that, if territorial pre-spawning
behavior is making life too rugged for your
Dwarf Gourami's tankmates, you might try
lowering the temperature a bit.
Dwarf Gouramis arrived early in American
aquaria. They were mentioned in a 1908 book
by Otto Eggeling and Frederick Ehrenberg,
The Freshwater Aquarium and Its Inhabitants. Eggeling imported some tropical fish directly
from Calcutta. That's gourami country. Was
the Dwarf Gourami among them?
A good male Dwarf Gourami will show clean
uninterrupted diagonal scarlet stripes against
metallic turquoise blue; I've never seen
the point of eliminating the stripes through
selective breeding to create the "Turquoise
Dwarf Gourami," which invariably presents
creases and dings in its metalflake coat!
Moving in the other direction, selective
breeding has eliminated the blue stripes
altogether, to produce the "Flame Gourami."
"Sunset Gourami" however, was the
name applied to these red C. lalia varieties by Atsushi Sakurai, in Aquarium Fish of the World, Singapore, ca. 1990. He says these were
first bred in Singapore in 1980.
Dwarf Gouramis like to incorporate shreds
of floating plants into their bubble nest.
A couple of strands of Cabomba or Myriophyllum
will do just fine.
The traditional Dwarf Gourami holds a special
spot in my heart because, when I was about
eleven, it was the first egg-laying tropical
fish to spawn for me, in a 5-gallon aquarium
on the toilet tank in a bathroom that I shared
with my brothers. The memory is a high point
of our childhoods. There are three detailed
descriptions of Dwarf Gourami breeding at
www.thekrib.com. Another, written for the Ottawa Valley Aquarium
Society by Darin Cowan and Elizabeth Webster
(they err in calling the Dwarf Gourami Colisa sota but their description is still good) is
archived at Fishaholics.
Though the Dwarf Gourami used to be recommended
as a good beginner's fish, I couldn't recommend
it whole-heartedly now to anyone. Dwarf Gouramis
have weakened in the last forty years. Now
they come to your LFS riddled with the tell-tale
lumps in their musculature of encysted metacercariae
formed by dormant parasitic trematodes. And
Dwarf Gouramis are martyrs to Camallanus, an insidious intestinal nematode.
Natural females are larger than males, plumper,
more silvery. The females are often held
back from the retail market now, or else
they come to you "juiced" full
of methyl testosterone to give them spurious
butched-up color. Such hormone-treated individuals
may prove to be sterile, if they can be induced
to spawn. When you call for them at your
LFS, you'll likely be told "we get no
call for them." You may have more luck
at your unselective low-end chain store,
where the untreated females can slip through.
Buy three if you need one, and quarantine
them carefully, with treatments for skin
and gill flukes, ich, and possibly for intestinal
nematodes.
All in all, you have a seriously diminished
chance of witnessing the beautiful spawning
ritual that impressed me so many years ago.
Now, if you were planning to establish a
clean, disease-free, tank-raised strain of
carefully-selected fishes of the natural
type, I'd pay a premium for those. I wonder
how many other fishkeepers would too. So
in the meanwhile, maybe your best source
of Dwarf Gouramis could be the auction of
a local fish club: another reason to join,
eh?
Singapore is the world's center for mass-produced
gouramis, among many other hobby fish. There
they are raised in concrete-bottomed outdoor
ponds protected by netting. Chicken manure
fuels a rich soup of green water algae, which
can drive the pH as high as 10.3 during peak
hours of photosynthesis! You could get a
clear picture of the fish-farm management
techniques recommended for pond-raising gouramis—
and other fish— in Singapore at http://www.dbs.nus.edu.sg/fish or http://www.science.nus.edu.sg/~webdbs/fish/gourami/gourami.html, both links now scrubbed from the semi-official
National University site, which made the
following recommendations, circa 1998:
"Another technique that could be employed
is the use of hormones and/or chromosome
manipulations to produce all male generations
of fish, as is done with tilapia. This would
increase the yield of the more valuable male
fish and reduce the number of the less-valuable
females. Finally a more systematic approach
should be taken to producing hybrids between
the different color varieties of dwarf gourami
and between the different gourami species.
This would create new and more profitable
varieties of fish in the future."
These repellant techniques
are actually commonplace.
But if you were to
ask anyone in the wholesale
import-export trade,
these practices would
be flatly denied
as unfounded rumors.
Omnivore diet. We think of gouramis as omnivores, eating
some green plant material to supplement their
diet. An inspection of the guts of C. lalia in Singapore fishponds revealed these contents:
fauna (in descending order of volume): cladocerans
(e.g. Daphnia spp), copepods, ostracods ("seed shrimp;"
this is an unexpected food item!), rotifers,
insects, protozoa; flora (in descending order
of volume): cyanobacteria (yes! another surprise
eh?), green algae, diatoms, euglenoids ("green
water" protists). I was surprised not
to see molluscs (snails). With a menu like
this, you shouldn't be surprised that Dwarf
Gouramis spend all day picking over the plant
surfaces in a densely-planted aquarium.
Macropodus opercularis (Paradisefish). Don't reduce this magnificent
fish to a "Paradise Gourami." This
is the "Paradisefish," period! It was
the first tropical fish (not a goldfish)
to reach Europe, exported to France in 1869
from Canton, where it had long been a traditional
fish for garden pools. Kept like goldfish
in glass vases in unheated European drawing-rooms,
Paradisefish survived and even spawned, before
the aquarium hobby really got under way.
And this is still a good way to keep them,
isolated in an unheated but planted aquarium
that is kept at room temperatures. My experience
has been that they aren't trustworthy in
a community, but Dr. Thomas Seehaus disagrees
with this general reputation.
Certainly M. opercularis need no heater; they are comfortable even
when water temperature dips below 60o. Males
will scrap fiercely with each other, once
they've reached adult size. And females kept
with a male are going to need some extra
space and pretty dense plant cover. I had
one male who lived solo for a long while
in a rectangular gallon glass vase with only
a single small potted Anubias and some Water
Sprite at the surface, with half an inch
of gravel to encourage bacterial nitrification
and regular 50% water changes. You do have
to keep Macropodus covered with a glass lid
at all times. Like many fish from weedy waters,
they have learned that often the only way
out of a constricted tangle is a good jump
over the top. At my place, that's a poor
gamble: Carpetfish!
This fish has a large natural range that
extends from Indochina and the northern Philippines
in the far south, into Korea. From Korea,
admirers introduced it into Japan. An inadvertent
release from a garden pond during a flood
in 1917 established M. opercularis in the wetlands of Niigata prefecture in
Japan, where Takashi Amano noticed them when
he was a boy. Doubtless it must also be human
intervention that carried these strictly
freshwater fish to the Ryukyu Islands and
to Okinawa. These islands weren't connected
with the mainland even during the deepest
marine regression at the height of the Ice
Age.
So, knowing they have such a wide natural
distribution, you're not going to be surprised
that there is a continuum of variation in
wild populations of Macropodus opercularis. Besides the richly-colored usual version,
there is a blond aquarium version with a
strong blue cast, owing to its genetically-suppressed
melanin cells and erythrocytes. Those are
the black- and red color-bearing cells in
the skin. The suppressed red coloration still
gets evoked in a kind of negative way, since
the ventral fins in the blond variant lack
the handsome red leading edge and tail markings
and the body stripes are washed out. In these
"blond" fishes the blue opercular
eye-spot also lacks its red margin. Though
they're often on the market and I've kept
them myself, I don't see the esthetic value
of this variant, as you can surmise.
There exist very strongly melanistic populations
of "Black Paradise Fish" that some
people like to call "Macropodus opercularis concolor," though they usually have to add that so-called
"hybrids" with the usual coloration
exist. Though M. opercularis concolor was imported into Germany in the 1930s,
the line has been diluted with outbreeding
to the regular color form. In these "concolor " types you can still see that the
dark scales connecting the eye to the bold
ocellated gill-spot are not suppressed; they
are still represented by a strip of darkest
scales that still leads to a smudge, all
masked by the general melanism of this dark
variant, which gives a black rim to every
scale and black edges to the anal fin. Can
you tell that this is the version of Paradisefish
to seek out, in my opinion? The darkest Paradisefish
I've seen on the web is Adam Lundie's photo
at www.fishprofiles.com, which really shows this fishes' sombre
glory.
A wild population of Black Paradise Fish
were discovered in the 1990s, during a survey of Hong Kong wetlands conducted by Prof. David Dudgeon. At first
they were taken for examples of M. opercularis concolor, but in 2002 they were described as a new
species, M. hongkongensis. I think they haven't appeared in the market
yet.
I also hear about a "new purple strain"
that loses its color as it matures. I'm skeptical.
Sounds like another dyed fish to me.
The Paradisefish is an ambush predator. In
the still and densely weedy waters that Paradisefish
come from, a predator could waste more energy
than it was likely to gain, if it tried to
pursue prey over any distance at all. So
Macropodus opercularis lurks just under the water surface, perhaps
waiting for an insect moving at the surface
within striking distance. This is why it
is content in such a small tank. Mature males
are intensely territorial and can't be housed
together: in fact when a large dark dominant
male rushes at another, even though the other
is safely housed behind a glass partition,
the aggressive move can cause the subordinate
male to turn pale and roll sideways in submission.
Females can also compete vigorously, with
head-to-tail broadside displays and menacing
slow reciprocal circling. Escalating threat
displays may culminate in shivering and sinking
of both fishes in unison, with spread opercula.
The dominant female darkens her colors. Submission
displays include a sideways roll to expose
the flank and, in more intense confrontation,
a head-up pose.
In a weed-choked backwater, a nearby male
may be quite invisible; I think this may
be why part of a dominant male's courting
and territorial repertory also involves breaking
the water surface repeatedly with his nape.
Loud splashes and ripples advertise his size
and strength— and distract you from the tv.
The ocellus or outlined eye-spot on the gill-cover (operculum) gave the fish its specific name, and whenever
you see that a fish has evolved an opercular
spot like a fierce eye, it's very likely
that gill-flaring will be one of its aggressive
moves. It surely is true in this case.
All this elaborated ritual, by the way, is
an effective way to minimize actual physical
damage to males during pre-spawning competitions.
In small tanks, where escape is impossible,
signals get crossed and fish can be damaged.
There's nothing "natural" about
fishes actually fighting.
Warmer temperatures encourage spawning behavior. Spawning involves a bubble nest.
I've noticed that
you can keep a male
for
long periods with
duckweed and floating
water
sprite overhead,
and he won't be inspired
to blow a single
bubble. Then introduce
a
plant with a bladed
leaf on a long leaf
petiole—
Amazon Sword would
do if you didn't
have
a big Cryptocoryne—
and watch him go
to work.
Try this for yourself.
My suspicion is that
rootless floating
plants don't register
to
him as suitable anchors
for a nest, and that
a blade leaf on a
long sturdy stalk
represents
a plant that's firmly
anchored in the mud.
There is survival
value in his choice:
a
bubble nest in floating
plants is at the
mercy of a freshening
current and could
be
swept away, whereas
one fixed to the
stems
of a rooted plant
offers a more stable
center
to his territory.
In Germany, Dr Thomas Seehaus has found M. opercularis to be no more aggressive than, say, dwarf
cichlids, but his beautiful photos show you the rich tangle of rootlets and
leaves his magnificent fish inhabit. Though
very small fish, or guppies with flaglike
tails are not suitable tankmates, he has
found that Paradisefish scarcely pay attention
to other species, as long as they are not
in reproductive mode and the territory round
the bubblenest isn't invaded. (I feel, conversely,
that the dense tangle of a clearly-defined
territory defuses some aggression.)
Thomas Seehaus has been consciously developing
a breeding line of Paradisefish to be as
much like wild-caught species as possible.
Over the years he has kept an eye out for
outstandingly beautiful and robust fish to
breed with his own stock. Recently, with
changed policies in Viet Nam, some wild-caught
Macropodus from Vietnam have been imported
to Germany, and Seehaus received a wild-caught pair from the neighborhood
of Quong Nam in Da Nang Province. He describes the wild form as less stocky
than his established aquarium strain, with
a more consistently displayed tailfin and
and an even blue background coloring that
only broke into speckles on the breast area.
His peaceful and somewhat lethargic Macropodus
pair showed no mutual aggression. When the
male was removed for a couple of weeks and
then returned, the female recognized him,
displayed for him, and the two spawned successfully
the following day. He noted her pale breeding
coloration.
But you should follow the link to the site,
at least to see what I'd consider the proper
environment for Macropodus.
Good spawning photos of a blond pair of Paradisefish,
also showing the nest and close-ups of fry
are at Wiljo Jonsson's site.
There are more pix
and a good informative
entry for M. opercularis at AquaWorld.
All in all, Macropodus opercularis is a seriously under-rated fish.
By the way, I'd be interested in finding
a copy of David Dudgeon, Tropical Asian Streams: Zoobenthos and Ecology, Hong Kong U. Press, 1997, to read the account
of M. opercularis there.
Pseudosphromenus cupanus dayi (Brown Spike-Tailed Paradisefish). This is a local sub-species of Pseudosphromenus cupanus, with native haunts in Sri Lanka. (Some writers
want to see it as a species on its own.)
Aquarium breeding activities have inadvertently
spilled populations of this sub-species into
the waters of the Mekong delta. By the way,
the curious mis-spelling of a genus name
that was meant to be "like Osphronemus" appeared in the original description
(a printer's error?) and is now cast in eternal
bronze by the rules of scientific nomenclature!
If you're intrigued by Anabantoids, but you
are uninspired by flashy and commonplace
bettas and degenerate gouramis, this is an
unusual labyrinth fish to keep, if you can
find it. If you do run into these fishes
at your LFS, you probably won't be impressed
with their pallid brown-and-tan coloring,
but once you get them comfortable in a typical
anabantoid weed-swamp they will color within
hours. This fish has a warm pinkish tan body
with two horizontal broken black stripes
that meet at the base of the tailfin. The
scales on the upper body are lightly tipped
black. The throat has a red blush; the unpaired
fins are a brick orange, darkening almost
to black, and tipped pale blue. The central
rays of the caudal fin are extended, with
black tips. And the ventral fins are brilliant
scarlet, tipped pale blue. Pretty stylish.
The fishes are shy, mild-mannered and graceful.
They move with an eelish, Betta-like stealth
through dense plant cover, using unobtrusive
rowing movements of their transparent pectorals,
though they are perfectly capable of a quick
dash for cover when alarmed. They lurk under
floating vegetation, their upturned mouths
adapted for feeding on water-surface insects.
Fruit flies make a welcome addition to their
diet; they're a little less fond of picking
food out of the gravel. They tolerate a wide
range of temperatures, from as low as 60o to 90oF.
Males will ordinarily ignore each other.
But they have a low-key subtle repertory
of aggressive threat signals. Ordinarily
the pennant-shaped ventral fins are carried
folded back hydrodynamically against the
body and are not used for active swimming
or balance. But when a male comes to a stop,
he back-waters with his transparent pectorals
and extends his ventral fins for a brake,
unfolding their bright red flags. This everyday
swimming technique has become stereotyped
into a defiant stance you could call "alert
display." In a slightly more aggressive
move, the more aggressive male smoothly follows
the other at a distance of 3 or 4cm. This
may be kept up for half a minute at a time,
but I never saw this "dogging"
escalate into a chase. Slightly more aggressive
again is "tail display," in which
a male faces his rival and swings his tail
to the side, holding his body in a curve.
"Tail display" brings the extended
fin rays into prominent view, so that the
rival sees that he is faced with a sexually-mature
male. In the type, P. cupanus, of which I was keeping the dayi subspecies, coloration is variable, but
it's interesting to note that all the variant populations have these behaviorally
essential bright orange to reddish ventral
fins and all have the caudal fin produced
to a point. We may selectively breed fishes
for arbitrarily-selected features that we
find appealing, but if left to themselves
female Spike-Tailed Paradisefishes apparently
select for masculine features that have a
function in aggressive display: red-flag
ventral fins and impressively extended black
tail fin-rays. They're important in the Spike-Tailed
Paradisefish message system.
A pair spawned for me under a coconut shell. (Often you
read of P. cupanus spawning in a bubble nest contained under
a broad leaf, in mid-water.) The female performed
a waggling head-down dance that induced the
male to circle her and nip at her flanks.
For her part, she was as aggressive as he
was. The dim shadows at the top of the coconut
shell seemed to attract them. There was no
trace of bubble-nest building. The episodes
of pre-spawning behavior were interrupted
by intervals of feeding and the usual solitary
cruising. Within a couple of hours of her
first enticing dance, spawning commenced.
The male circled round the dancing female
with increasing excitement, as they rose
up into the darkness under the shell. He
embraced her in his tense curved flanks (this
reads like a romance paperback with an embossed
metallic cover) and they rolled together,
paused a moment, and she expelled 7 to 10
eggs, each slightly less than 1mm in diameter.
The eggs sank slowly, and when the spawning
pair recovered, which seemed to take slightly
longer after each embrace, they would both
catch up the eggs and carry them up to the
roof of their coconut-shell cave. A few bubbles
were caught up there, too rudimentary really
to term a "bubble nest." Then an
episode would follow of checking the lower
side of the coconut shell for any overlooked
eggs, and a little search in the nearby gravel.
Then the female would initiate the next embrace
sequence, with a renewed head-down waggling
dance.
A "sneaker" male? The extraordinary thing about this spawning
sequence is that a second male in the 10-gallon
tank found a cramped hideout under a nearby
shard of coconut. There he lurked like a
bandit behind a rock in a western, about
ten centimeters away, waiting his chance,
and at the right moment, he joined in the
embrace. The spawning pair seemed too preoccupied
to chase him away. Did he contribute his
milt? He certainly took some eggs in his
mouth and rose up in the darkness to the
roof of the shell. Where he deposited them?
Where he ate eggs? I can't tell you. If this
was a so-called "sneaker" male,
it's a well-documented tactic among some
Lake Malawi cichlids. The surprises for me
weren't over with the spawning. Afterwards
it was the female who took over guard duties
and chased off both males. But even her spawning
behavior waned after forty-eight hours, and
there were no fry that I found.
Links. The best description of Pseudosphromenus cupanus dayi posted on the Web, with photos that include
some breeding shots, is Russell Carroll's.
Grant Gussie's good brief newsletter article,
"Pseudosphromenus dayi," is archived at the Calgary Aquarium Society website and at http://labyrinth.aquariumsite.org/
Trichogaster leeri (Pearl Gourami). One of the ten most beautiful freshwater
tropical fishes. Why do so many aquarists
struggle with the aggressive T. trichopterus and ignore this equally hardy, gentler beauty?
Bleeker, who first described many of the
Dutch East Indies' fishes, named this one
in 1852 to compliment his colleague, the
physician Dr. J. M. van Leer.
Warmth is more important to Pearl Gouramis
than water hardness or pH. Sexing immature
Pearl Gouramis may be difficult. Sex of mature
fish is easily determined: as a male matures,
the rear corner of his dorsal fin will become
more pointed and will eventually get to be
pennantlike. By contrast, the female's dorsal
keeps the rounded rear corner that all juveniles
have. As they both begin to be ripe, the
male's throat and belly will redden to a
fiery flame-orange glow. Females are slightly
smaller and plump. Towards breeding time,
the female will noticably swell with roe.
The fish aren't shy, once they've settled
in. Touching, testing and nudging is constant,
with the threadlike pectoral fins in full
play. Keep a single male with a small harem
of females, to cut down on sparring. Pearl
Gouramis get to be a full 4" (12cm);
they are cramped in any less space than what
a long 20-gallon tank affords. Dense planting,
especially a tangle of floating Water Sprite,
cuts down on territorial aggression, and
the Pearl Gourami will choose an especially
broad leaf to stabilize the bubble nest,
which may be large and untidy. The eggs contain
a droplet of oil that makes them buoyant.
You might offer a chunk of floating corkbark
for this,— or a margarine container lid,
as does Heather Hertziger.
Here's another species that originated in
the vast flat savannas drained by the Great
Sunda River during the glacial age and then
got isolated in separate relict populations
in Malaya, Sumatra and eastern watersheds
of Borneo, when the level of the South China
Sea rose and drowned the plain. The fish
are seldom found in open water. They prefer
shallow, thickly overgrown still, even stagnant
waters of ponds and slow streams.
The outstanding description of breeding Pearl
Gouramis is posted at the "NotCatfish" site. This description applies to breeding all
kinds of Anabantoids. It offers detailed
techniques for encouraging spawning behavior,
by setting up the male alone in a planted
aquarium, by raising temperatures slowly
to the low 80s, lowering the water level
gradually, and cutting down on feed, all
to mimic the dry season. The breeding description
also punctures the old tale of Anabantoid
fry perishing in droves as their labyrinths
were developing. You've heard that old tale
endlessly, and I have always given it credit
myself. Perhaps the real killer, it would
seem, is ammonia levels that can rise in
overcrowded fry tanks, which force the fry
gasping to the surface before they begin
to succumb. All in all, this is a very worthwhile
description.
You should also read Terry French's extended description of breeding Pearl Gouramis and raising fry
at the C.A.F.E. website.
The indefatigable Kaycy Ruffer, who has bred
everything she can get her hands on, found
that her T. leeri spawned in a mere 10-gal. tank; she describes
the event at her website.
And Heather Hertziger's article on breeding them and raising the fry offers
a few twists of her own.
Another excellent account of breeding T. leeri, by then 16-year-old Graham Nicholls, is at
AquaWorld e-magazine. )
Trichogaster trichopterus. Three-Spot, Blue,
Gold or Opaline Gourami. We rarely see the wild type of T. trichopterus, which is the plain silvery "Three-Spot
Gourami." The blue variant, which originally
came from Sumatra, took its place in aquaria
long ago. The "Opaline" variant
of T. trichopterus was first bred for the market by a Mr. Cosby,
of Texas, I remember hearing. The pleasure
I get from a good example of an Opaline Gourami
lies in its quite natural air; it doesn't
look like a "bred-up" fish to me.
Of T. trichopterus' numerous domesticated color variants, the
"Opaline" is the handsomest, I
feel, for in the golden form the gold is
never unalloyed, but always dirtied with
black that doesn't complement the ground
color.
Opaline Gouramis are too carelessly bred.
A private hobbyist with a good eye (that's
you) could make improvements in just a few
generations. What are the "points"
of a good Opaline Gourami? In my own opinion,
a good Opaline Gourami shouldn't reveal either
of the flank spots that inspired the name
"Three-Spot Gourami" that is given
to the natural form of the species. (The
"third" spot was the eye, as you
are tired of hearing.) Instead, the spots
should be completely subordinated to an all-over
marbleized patterning of steel blue and dark
ink blue. There are well-placed clear turquoise
spots in the fins. Crimped or clipped pectoral
fins aren't just less picturesque; the "feelers"
are dotted with taste buds, and they feature
importantly in aggressive and courting behavior
for all the "threadfin" gouramis.
When males' chemoreceptive "nares"
at the end of the "feelers" were
experimentally cauterized or clipped, the
fish seldom built nests or spawned successfully.
Make sure the threadfins are uncompromised
when you buy your fish. There are pix of
"poor" Opaline Gouramis all over
the web; a rare good one that displays the
"points" I mean is illustrated
at www.animalatlas.com.
In preparation for spawning, the male stimulates
the female by his courting and nest-building
behavior. The aquarium water contains his
steroid glucuronides, which promote the maturing
of her eggs. Females also produce pheromones.
In U. of Hawaii tests, male T. trichopterus distinguished among water containing a ripe
female, an unripe female and empty water.
The upshot is, that if you are ripening a
male and a female, it helps to have them
in the same aquarium, separated by a divider.
If they are in adjacent tanks, you might
hasten the ripening process by exchanging
a cup of water between the tanks.
What is the "right" temperature
for T. trichopterus Gouramis? Tests at Windward College HI showed
that nest-building and egg production occur
at temperatures between 73 and 84°F,
with no "optimal" temperature within
that range. (No egg production occurs at
68°F.)
T. trichopterus has a highly developed repertory of threat
displays that are played out like poker hands
in establishing a dominance structure. I'd
like to describe them, since I've never seen
them all described, and I'm curious to hear
whether your observations support this vocabulary.
Aggression, in increasing order of urgency:
1. Alert stop, with threadfins extended.
2. Thread-fin grope, using one or both pectorals.
3a. Flank display, with fins flared. In a more intense action
this display can cut off the other fishes'
movement with a T-block, and the flank display can be intensified
with a shimmy wave.
3b. Reverse flank display, a kind of broadside 69. It can be intensified
with contact, in a slip-motion. If both fishes respond aggressively, slip-motion
evolves naturally into a spin chase.
3c. Face-off. This can be intensified with gill flare, a gullet flare becoming a yawning gape. And the effect of a face-off is made more
aggressive with tail flexing, in which the tail is flexed to the side
in order to show it.
4. Charge feint can evolve into a chase.
5. Butting is more aggressive still. Anal fin butting
is more intense when it's in the genital/vent
area and most aggressive when the throat
is the target.
6. Mouth pull can include a "kissing" rasp.
7. Color changes can accompany all these aggressive actions.
Darkening is aggressive; blanching is submissive.
8. Vocalizations.
Submission (also in approximate order of
intensity)
1. Back-pedal.
2. Sinking, head down, or more intensely, head up.
3. Rising for air. A "time-out" signal.
4. Tilt
5. Body curve.
6. Blanching.
For the voyeuristically inclined, Dave's Aquarium site has excellent photos of the spawning embrace,
the bubble nest entwined in floating plants,
and the young hatchlings. Dave gives a good
short description of the action, too.
A long, detailed article describing techniques
for commercial breeding Trichogaster trichopterus in Hawaii is posted by the Center for Tropical
and Sub-Tropical Aquaculture at www.biofilter.com. It has some points that will be interesting
to you, too. These breeding techniques apply
equally well to the other Trichogaster species, and to Colisa also.
Badids, the "not-labyrinth" fishes.
The few genera of Badis and now Dario make up the family Badidae. They are related
to the Nandids, the "leaffishes"
and they are close cousins of the ancestor
of all the labyrinth fishes. Probably their
own ancestors were related to cichlid ancestors
somewhere even earlier, before the close
of the Jurassic. The Badids are Laurasian
fishes from the northern supercontinent of
the Mezozoic Era, whereas Cichlids got started
in Gondwana, the southern supercontinent.
The Badid family homeland ranges from the
Ganges lowlands of India, eastwards to the
mid-Mekong in Thailand, south into peninsular
Thailand and north into mountainous upper
Burma and southern China. You see what a
strong range overlap there is with the Anabantoid
families.
Badis ruber ("Badis badis burmanicus"). Badis ruber is recently re-established as a senior synonym
for the more familiar designation of this
fish as a sub-species, B. badis burmanicus. The "Burma Badis" occurs in southern
Burma and the mid reaches of the Mekong,
in slow-moving streams and weedy ditches.
Recognizable from other Badis by the large
dark blotch on the caudal peduncle, this
little fish maxes out at 8cm/3 in.
Sven Kullander and R. Britz have revised
the family Badidae, with a new genus, Dario, for three small Badid species, that are
among the smallest Perch-like fishes known,
and ten new Badis spp. There's an abstract of their article at
the Swedish Museum of Nat. Hist site. At the same site, B. ruber and other new Badis species from Burma are illustrated from museum specimens and
briefly mentioned by C.J. Ferraris, S. Kullander
and F. Fang.
My four were new to me as I first set these
notes down in March 2003. I'd been told not
to try them in a community, even quite a
gentle one, because they'd be outcompeted
for food. I'll be lucky if they deign to
eat any flake feed at all, another source
warned me, and sure enough, they haven't.
I saw right away that they are little ambush
predators. They lurk, threateningly immobile,
challenging one another. I provided plenty
of coconut-shell hideouts, because I heard
they prefer a cave as the heart of their
mini-territory, in a 10-gallon tank stuffed
with young Java Fern, where the water circulation
is mild. Temp 71-77°F. My water is very
soft, lightly buffered with some crushed
coral to keep it about pH6.8.
In early September, after many weeks of heat
and tank temperatures into the low 80s, I
lost one of the males, with internal bacterial
infections that appeared as popeye and intestinal
edema. Several web posters are suggesting
that too much heat promotes such bacterial
infections in Badis. My fishes have been
raised almost exclusively on blackworms,
too rich a diet I know, but they have never
looked at any flake feed.
Don Kinyon had six juvenile Badis badis he located through the Internet; he set
them up in a 40g. at about 74°F with
bogwood, inverted flower pots, Java Fern
and Java Moss, with some Croaking Gouramis
and Corydoras for company. His Badis accepted
frozen and freeze-dried foods, white worms,
chopped earthworms and mosquito larvae. A
male's breeding dress, black body with blue
fins, first alerted him that there were fry
under one of the flowerpots-- about a hundred
of them. See his article, which was first published in the Potomac
Valley Aq. Soc. journal, Delta Tale, vol 30, pp2-3.
Old ichthyological engravings illustrate
M. van Oijen's article about the convoluted
history of this species' names, "Badis badis (Hamilton, 1822): een bron van misverstanden"
at the Dutch NBAT site.
And there's a nice informative illustrated article on Badis badis at the Aquaworld site.
The web's prettiest series of Badis badis photos, showing the color changes that gave
this fish the nickname "Chameleonfish,"
is at the Apist-o-Rama site. But the widest range of Badis (and Dario) spp. photos (with English captions), including
rare and recently-discovered Burmese ones,
is in Nonn Panitvong's Thai website, siamensis.org (click on "article").
Several short reviews of Badis are at the
Age of Aquariums site.
Arthit Prasartkul bred his pair of Dario dario (aka "Badis bengalensis") the newly-discovered (1999) miniature
"Scarlet Gem" Badid. You'll have
to excuse his artful vertical layout. It's
at www.aquabox.info under "article."
Dave Sanchez started a Badis research group,
badisbadis@yahoogroups.com, in Jan 2002,
originally as a spinoff from the Apisto Study
Group. He has Badis ruber breeding in a community, taking up residences
in PVC pipe. When the young have absorbed
their yolksacs and are clearly showing their
eyes, he siphons them out and raises them
in plastic shoeboxes, like killies, with
strands of Java Moss, a technique he calls
a "very simple and very prolific way
to get a whole lot of these guys real quick."
Some sample alerts from the Yahoo Badis group:
Petsmart outlets (KS) had Scarlet Badis from
the FL wholesaler Segrest. Jan 2003.
William King warns that the fry are susceptible
if they aren't steadily fed, even as large
as half an inch.
Francine noticed that the male of the B. badis pair intimidates the female into a frozen
position by just being near her, a behavior
I'm already noticing in B. ruber.
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