The Skeptical Aquarist

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.