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The Mystery Solved At Last

By Trey Tabb

When the fishkeeping hobby first began in the United States, the keeping of America's native fishes was very common, as the selection of available exotic species was quite limited. As developments in technology made it easier and more practical over time to import and keep species from around the globe, interest in north american fish waned considerably. That's a shame, too, because many of our native fishes are every bit as alluring as any imported jewel from some far-flung corner of the earth.

This is a story about one of those fish, the Bluenose Shiner, Pteronotropis welaka. Discovered over a century ago in Welaka, Florida, hence the name, this fish has confounded all who have kept it since, prompting one of it's most faithful fans to coin it's nickname of "Pteronotropis ENIGMA." Even though the natural history and reproductive habits of this fish have been studied exhaustively, and despite hundreds of attempts under every conceivable condition, this fish has almost never spawned in captivity. The first success came 73 years after the fish was discovered, a long wait indeed, and that feat was duplicated only a few more times in the subsequent 35 years, with most of those successes being either accidental or accompanied by dozens of failures.

The Bluenose, being a North American temperate zone freshwater fish, has a definite spawning season, of early summer, brought about by certain environmental cues. That holds true for most non-tropical fishes, and for a great many tropical ones as well. Temperature, photoperiod, food availability, changes in hardness or pH or salinity and more can all serve as the cue, or combination of cues, which bring fish into spawning condition or even trigger spawning. The Bluenose is certainly no exception, and conditioning this fish requires months of effort. To make matters even more complicated, this fish is a "cuckoo" spawner, or nest associate, which deposits its eggs in the nest of another species, the Longear Sunfish, Lepomis megalotis. While this fish has spawned in aquaria some half a dozen times over the past century without the presence of a Longear nest, it really seems to strongly prefer having a nest handy.

Although getting this fish into robust spawning condition is relatively easy, the biggest problem with the Bluenose has always been the Longears. It stands to reason that providing the conditions which make Longears spawn would in turn provoke the Bluenoses to follow suit, but in practice that has proven untrue. In the first place, the Longears are a lot easier to please, so they may be eager to spawn while the Bluenoses are not. Another big problem is the fact that the Longears have a nasty habit of killing the Bluenoses when they are establishing their breeding territory. In nature, the Bluenoses simply stay away from the Longears until they see a good opportunity, and then they rush over to the nest to dump their eggs whenever the nest is momentarily unguarded. While certainly very problematic, that obstacle has been overcome in an amusing array of ways ranging from partitions to plastic sunfish in various attempts. A great many very highly skilled expert aquarists had tried and failed with this fish, so when I decided to make my own attempt to get it to spawn, I didn't really think that my chances of success were very good. However, I did have a theory.

Timing is everything for a cuckoo spawning fish. If the eggs are laid too early, they might hatch before the host's eggs are even laid, alerting the host to the intrusion. If they are laid too late, the host's fry may well eat the eggs, or fungus from infertile host eggs could kill the intruder's eggs, or the host may even be of the type that likes to clean and move the fry, which would destroy the unhatched eggs. Indeed, the eggs have to be laid at just the right time, which means the cuckoo spawner has to somehow know just when the right moment has arrived. When I was doing some research on a different species I wanted to try, the Rainbow Shiner, I learned that it too was a cuckoo spawner, and that when it's favorite host fish spawns, the Rainbows sprint upstream to the host nest for immediate spawning. How do they know the correct moment has arrived? They smell it. When the leftover milt from the male host fish drifts downstream, the Rainbows recognize the smell and know that the host nests are ready to parasitize. They ignore the smell of milt from the other "wrong" species which may also be spawning upstream. In further research I learned that the introduction of host species milt can often bring many other cuckoo spawning fish into breeding condition within a few days all by itself. I thought about the Bluenose Shiner, and all the times that fish in obvious spawning condition still refused to spawn, prompting their exasperated keepers to exclaim "what are WAITING for, you stupid fish?," and I suspected that I finally had the answer to that question.

I'm very happy to report that my theory was apparently correct. The addition of Longear Sunfish milt to a tankful of Bluenose Shiners already in spawning condition will trigger spawning, possibly within hours! I don't yet know if the introduction of milt alone will bring the Bluenose into spawning condition, but I certainly hope it does, for as I'll describe later, conditioning this fish the traditional way is rather time consuming. It is my hope that some fish farmers reading this article will find ways to improve and perfect my method, finally allowing this fish to take its rightful place as a mass-produced hobby favorite.

Why all the fuss? Well, just look at the picture. This little beauty is a dazzler by any standard. The finnage is very unique in shape, and this fish makes good use of it by flaring up like a Betta on occasion. The dark blue-black band down the side is punctuated by numerous little silver scales which shine like a handful of diamonds scattered over a piece of black velvet. The large, showy fins have a nice pale to bright yellow color which is shown in good contrast by the black markings around the edges. Finally, of course, there is that glorious caerulean blue snout which gives this fish it's common name. The bright blue of a spawning male's snout is so bright that it can sometimes be the only thing visible to betray it's presence in the dark, deep murky water it likes to call home. The female is rather plain in comparison, but comely in her own way.

Looks aside, this fish has much more to offer as an aquarium species, but only for those who will give it the care it requires. They usually adapt well to aquarium life with some care, but just as often as not they go through a period of adjustment which is very hard for them. This is not a fish for the novice or casual hobbyist, so far at least, and even the experts have experienced problems. This fish is a challenge, but fortunately those who specialize in keeping native north american fishes thrive on challenge; it is partly why they keep such species in the first place. Otherwise, this little jewel of a fish is peaceful toward it's tankmates, lives in schools, doesn't tear up plants but loves to eat algae, only gets a little over two inches long, is willing to eat almost anything after some adjustment, and will live under a wide variety of tank conditions. In short, it is an almost perfect aquarium fish for those who take good care of it.

This fish lives in the southeastern United States of Florida, Georgia, Alabama, Mississippi, and Louisiana. With a distribution like that, it might seem that the fish is common. However, that is not the case. This fish is very picky about it's preferred habitat, and while it enjoys a wide distribution range, it can only be found in a few little spots scattered throughout that range. The same can be said about all the nine species in the genus of Pteronotropis, and in fact they share many other characteristics, most notably the annoying habit of preferring to live in really hard-to-reach places which can only be found after a long search. They are schooling fish, but to find more than a dozen at a time is a rare thing, and it may require a half-mile walk downstream to find some more, for they only congregate in those little spots where everything is juuuusst right. Each species has it's own preferences, and naturally, the Bluenose's preferences are for the most inaccessible and aggravating places imaginable. While the others mostly prefer tannic or clear, shallow water with little dropoffs and waterfalls and sandy bottoms, the Bluenose likes deep, dark, dank, murky water with mucky muddy bottoms once best described as "fetid mire." Collecting this fish is a real chore, and it is nearly certainly a lot more common than officially recognized simply because it is so hard to conduct fish sampling operations in the areas where it most likely occurs in greatest abundance.

Well, that's quite enough prefacing., so now I'll reveal the details of how I got this fish to spawn. This will be one of the stranger spawning accounts ever written, because while I went to a lot of trouble to set everything up for this little experiment, I wasn't around for the actual spawning. I currently work as a longhaul truckdriver, and so I had to enlist the aid of the lady who feeds my fish. Tina, a newcomer to the hobby, made observations and told me what she observed during telephone conversations every few days, and I told her what actions to take based on those observations. I prepared everything that she would need in advance in order to make things easy for her.

The Pteronotropis species are all very, very picky about water current, and it's one of the chief factors which determines where they choose to live and spawn. I decided to use fish caught in a pond instead of those from a stream, figuring that they wouldn't be as hard to please in an aquarium. This fish doesn't normally live in ponds, but I knew of one which was built by damming up a creek, and it was full of Bluenoses which were doing quite well after many years. I foolishly went alone, and after about four hours of hard work, I had managed to collect three males and five females. I took them home and put them in a little 10 gallon tank by themselves while I got their new tank ready.

The tank I used was a 30 gallon "long." I covered the bottom with pea-sized gravel to a depth of two inches, and then I covered that gravel with another inch of plain black potting soil, the kind with nothing added to it. I wet the soil and packed it down pretty hard, and then I covered it with a thin 1/4 inch layer of smaller grade dark brown gravel. Then I covered it all with saran wrap, placed a saucer on top of the wrap and filled the tank with water. It didn't work as well as I had hoped it would, but the water was a lot clearer when I was done than it would have been without the saran wrap. In fact, removing the wrap made the biggest mess, but it would have been worse without that thin layer of gravel over the mud. I should mention that the water I used was a mix of two-thirds distilled water and one-third water from the pond where I got the fish, which I filtered before use. I usually go half and half, but I spilled a bucket on the way home. As for decor, I used a whole bunch of fake plants around the back and ends of the tank, leaving the front clear for swimming space. The filtration was a combination of an Aquaclear 200 mounted on the back near one end, and a small 100gph canister filter. The intake for the canister was on the same end as the Aquaclear, while the output hose was mounted on the other end, pointed at the opposite front corner, and only one inch down from the water's surface. I added a little amazon extract as well. All in all, it wasn't too bad a mockup of the original pond. As a finishing touch I used a lightstrip from an old 10gallon eclipse hood for illumination, and it was set over on the end with the Aquaclear, leaving one end brightly lit and the other much darker. This works very well with other members of this genus, and they usually tend to stay on the darker end. Finally, I hooked up a chiller unit to bring the water temperature down for mimicking winter. These fish need to be overwintered before they will spawn in the spring. Some breeders have a "cold room" in their house which serves the purpose, but down here in the south we have to use a chiller if we want to simulate winter in the middle of summer. The fish were introduced to the tank before I started to drop the temperature, and the water parameters were as follows: pH- 6.6, hardness- 7DH, temp- 74F, photoperiod- 11 hours. After letting the fish get settled for a day, I left specific instructions on a little calendar which told Tina what to do and when. Over the next month, the photoperiod was decreased to 8.5 hours per day, and the temperature was lowered to 59-60. A 25% water change was conducted with distilled water that I had set out for the purpose. When I got home, things were pretty much right where I had expected them to be, and the tank was nearly fully in winter mode. I checked the food supply to make sure that Tina had enough food at the ready to feed the fish, and enough distilled water for weekly 15% water changes. The fish were fed the best foods I could scrounge up for them, in order to help build up their eggs. They liked to munch on spirulina wafers, and they ate plenty of daphnia and ostracods. Oddly enough, they wouldn't eat brineshrimp at all, even though many other people who have kept this fish report brineshrimp to be one of their favorites. I guess mine were just a bad batch or something. They also ate mosquito larvae, the smaller the better, and good old Tetra brand flake food. If I had thought about it at the time, I would have added Cyclop-eze to the menu. I hit the road again, knowing that everything was just fine and dandy.

Unfortunately, things didn't remain fine and dandy. I had planned to keep the fish winterized for three months, but Hurricane Ivan didn't agree. That storm wreaked havoc on my whole fishroom, as well as my goldfish ponds and numerous other things. Almost everything was trashed beyond hope, and the power was out for over a week. That of course meant no more chiller, and by the time I got home, the temperature had already risen to 66F, a good month ahead of schedule. I got things put back together and running, and was considering starting all over again, but I noticed that the fish were looking a lot friskier than they had looked the last time I saw them. The females were plump, and the fins of the males had grown quite a bit, which they do as spawning season approaches. Finally, the blue on the males' snouts was intensifying and spreading. I decided that going backward was probably not such a good idea, so it was time to let the springtime come to the Bluenoses' tank. I set up a new schedule of twice-weekly waterchanges and photoperiod increases of 15 minutes every two days. Then I set up another tank, a 20 gallon high, right next to the Bluenose tank on the end opposite from the filter. That tank was a very simple setup containing only one single male Longear Sunfish and an undergravel filter. Then I went to a nearby sportfish farm run by an aquaintance of mine to get some Longear milt. He had been hit hard by the hurricane as well, and didn't have any handy, so we had to milk, or strip, some males for their milt. I took it home and put it in the fridge, where he assured me it would last long enough for my purposes.

After that I made a waterchange in the tank myself, this time making sure to stir up some of the muddy bottom on the end of the tank next to the Longear's tank. When I was done, a 3 or 4 inch patch of mud was gone, leaving an exposed pit in the underlying gravel, which looked sort of like a longear nest. I didn't want the Bluenoses to get accustomed to the pit earlier and subsequently ignoring it later, so I made it only after adding the Longear so the Bluenoses would possibly think that the Longear had made the nest. I checked the various parameters, and found the following: pH- 6.8, hardness- 6, temp 66, and photoperiod 8.5 hours per day. I hit the road.

A few days later I called Tina for a status report. The temp had risen to 67 or 68, the photoperiod was 9 hours per day, and the shiners were avoiding the end of the tank next to the Longear's tank. That was excellent news, for it meant that they could see the Longear and were trying to avoid his nesting area. I told Tina to continue on schedule and watch for any important developments. In another two weeks the photoperiod was up to 10.5 hours per day, and the temperature had risen to 73-74F, and the fish were doing their courtship behaviors. I really wish that I could have been there to see it. Tina said it was spectacular, with the full colors, fully flared fins, and the males doing some head-to-tail full-body shimmy sort of dance toward each other in an intimidation display. I had her do one last waterchange, a 25% one instead of the usual 15%, and increase the photoperiod by another 15 minutes. The next day things were looking about the same, so I had her go to the fridge and thaw the little vial of milt until it was runny, but not too warm. Once it was ready, she was to put it into the tank, as early in the morning as she could, and then go back one half-hour later to shut down the filters, and then go back again one more hour later to put the piece of cardboard I had prepared in between the two tanks so the shiners couldn't see the sunfish. I should point out that she was really starting to get fed up with me by this time, but she was a real trooper. After that, I told her all she would have to do would be simply feed the fish, and just flake food at that. She was happy.

About 5 or 6 days later I called to see what had happened. I was very nervous, but tried not to get my hopes up too much. I couldn't believe the news when I heard it; the tank was full of little baby fish which were hanging out at the water's surface along the glass edges of the tank. YES! YES!! YES!!! My jubilation didn't last very long, though, for at that moment I realized that I had made a critical blunder. I had not prepared any food for the fry. I never really expected that there would BE any fry, and the hurricane cleanup crew had destroyed my golfish pond full of greenwater. Not that it mattered, really. Water changes were one thing, but there was no way I was going to get Tina to feed the fry greenwater, complete with yummy aufwuch scrapings from the aquatic plants, even if I had it already bottled up and ready to use. That really annoyed me, too, since the fry of this genus are as easy to raise as guppies after that first week of greenwater. As for the fry, they are about 1/4 inch long and have only one half the girth of newborn guppies. They are remarkably fast and agile swimmers which stay at the surface of the water, well away from the adults.

When I got home, I checked the water parameters once again, finding the following: pH- 6.9, temp- 75, photoperiod- 10.75 hours/day, hardness- 5. I don't think any of these changed much after the spawning, so that's probably what the parameters were when they spawned. By the time I got home, most of the fry had already starved to death, and the adults weren't looking very good, either. Fungus had set in, due very likely to infertile eggs and dead fry, and it had spread like wildfire. I was only able to find 6 surviving fry, and they've all since perished. Tina and my mom estimate that there were about 50 fry visible at any given time for about a week. I don't know how many times the fish spawned, but it's common for the other fish in this group to spawn several times, once every few days, for about two weeks. Those others are simple egg-scatterers, though, so I doubt that's the case with these cuckoo spawners. The Bluenose is an avid egg eater, by the way, which leads me to conclude that they did indeed use the nest I provided them. If they hadn't, they would have eaten the eggs and there would never have been so many fry. The large size of the pea gravel allowed the eggs to fall beyong the reach of the spawning fish.