By Ted Judy
Waiting for fish to spawn and fry to grow is like watching water boil. It seems to take forever. This week things are a little slow in the fish room. The next group of livebearers should be giving birth soon, two more rainbow fish species’ fry are surviving this month (knock on wood) and there are five pairs of characins/cyprinids set up to get some eggs from. And the waiting is finally over for one of my long-term projects: Steatocranus gibbiceps.
A buffalo head cichlid Steatocranus gibbiceps
S. gibbiceps is one of the buffalo head cichlids from the Congo River. This is an uncommon import that I purchased almost six months ago and have been waiting for a spawn ever since. The fish are relatively shy, so waiting for a spawn has been a bit like watching paint dry. All I really do is feed daily, water change weekly and use a flashlight to check on the fish (and to see if there are eggs in the caves) a couple times each week. Now that the female is raising a brood they are easier to see, and I have to ask myself, ‘Why do I have this fish?’. S. gibbiceps is a smaller version on the standard buffalo head, S. casuarius. The most noticeable difference between the two species, when the fish are young adults, is that the S. casuarius have scales with light edges and dark centers, and S. gibbiceps have scales with dark edges and light centers. Wow! Eye popping… All that color and shy to boot!
Looking around the fish room I can find several other fish that are not going to win many beauty contests. There are the Poecilia butleri from an obscure river in Mexico. These mollies are a lovely shade of light gray overlaid on a base of pale white. The males have a little yellow… very little yellow. I was gifted some cute little Xiphophurus andersi, one of the true swordtail platies, that is very rare in nature. Gravid females look like a robust female feeder guppy. Males have a little curved spike of a tail, but no color to speak off. Not that you can easily tell, since all they do is hide.
I just picked up two more species of Steatocranus: S. irvinei and S. glaber. They are still fry and I will probably have them for a year or more before they even consider the opposite sex attractive in a grade school I-slap-you-because-I-like-you kind of way. The S. irvinei has the reputation of being very, very mean, which is a great compliment to its flat-gray color and potential to grow over a foot in length.
Here’s a beauty! Xenotoca melanosoma… I am told that when the males of this endangered goodeid livebearer really color up they look like the bluing on a gun barrel. Apparently the females do not care, because they keep pumping out the babies and the males never seem to have to color up at all.
Why do I have all these fish that are chromatically challenged? Each species is either a challenge to breed or rare. The challenge to breed category needs no explanation. I like a challenge. Rare is important. In many cases the species is threatened or endangered in the wild. Sometimes wild populations are just fine, but they are protected and what we have in the hobby is all we will ever have. Regardless, it is important to keep, breed and distribute rare fish. Even though S. gibbiceps is not the most beautiful fish in the Congo River, it deserves a chance to be established in the hobby. For some species, like the Mexican goodeid livebearers, a chance to stay established in the hobby may be the only chance they have to remain in the world. So make a little space for the brown, mean and rare (they are not usually very expensive… unless I want them).
Posted December 16th, 2009. Add a comment
By Ted Judy
There are many species of tetras, barbs and danios that are not difficult to spawn. A good rule of thumb to figuring out a species’ difficulty is to compare prices at a fish store. Fish that are common and inexpensive are most often farm raised and easy to breed. The poster-fish for this group is the zebra danio Danio rerio. There are two challenges for the hobbyist breeder when working with these species. First, collecting the eggs can be impossible if the breeding tank is not set up to catch eggs. Second, raising the very small fry can be a challenge without the right foods ready when they are needed.
I breed most of the tetras, barbs and danios in 2.5 gallon tank. When the fish are very small, and lay a lot of eggs, I usually put a lot of yarn mops in the tanks. After a few days the fish have deposited plenty of eggs in the yarn. Some will get eaten, but there are enough hidden in the mops to meet my modest requirements (I do not really need or want more than a dozen fry). Larger species tend to be better at eating their eggs, so I use a false bottom in the tank made from a piece of plastic needle-point mesh cut to fit into the 2.5-gallon tank. I cut the screen so that it drapes in the bottom. I use a couple pieces of PVC to hold the plastic off of the glass.
A spawning mops hides the eggs from the parents so they do not get eaten.
Creating a false bottom using a screen is another way to separate parents from their eggs, and works best with larger species that tend to eat eggs off the spawning mop.
Once the screen is in place I add plants or yarn as a place for the fish to spawn. The eggs filter through the plants and then fall through the plastic mesh. Since the bottom of the tank is bare the eggs easily seen. After the eggs are laid I remove the fish, screen and pvc. I leave the plants and add a drop or two of methylene blue. I cover the top of the tank with a piece of cardboard to block the light. Most species’ eggs hatch in less than three days, and the fry are ready to eat a day later.
The first food I use is paramecium. If you do not have a paramecium culture there are products on the market, called fry foods, which are designed to provide small particles for baby fish. A good supplement to a food product is ‘sponge grunge’. Squeeze a well established sponge filter into the tank with the fry and some plants. The microorganisms in the sponge will start a colony that will feed to fry. After a few days the fry can eat microworms. One trick I use is to keep my microworm cultures very wet, about the consistency of a thick soup. The media in the culture contains all different sizes of the nematodes. When I feed from the culture, I scoop a little of the media onto my finger and swirl it into the tank with the fry. Yes, it clouds the water… but the fry do not care, and they are getting very small food.
After a week most fry can eat baby brine shrimp and they are off to the races. With lots of food and frequent water changes they will grow fast.
I have ten 2.5-gallon breeding tanks in my fish room. From spawn to relocating the fry to a growout tank tanks about 10 – 15 days. If everything works out perfectly I could breed 20 – 30 species of ‘easy’ tetras, barbs and danios in thirty days. Plans rarely work out perfectly, however, and I am happy to be successful with 5 – 10 successful spawns each month.
Posted December 8th, 2009. Add a comment
By Ted Judy
I am quickly discovering that the limiting factor controlling the number of species that will breed in my fish room this year is tank space. More specifically, grow out space. I can set up many species in 2.5 gallon tanks and get eggs within just a couple days. The fry can stay in the small tanks for quite a while, but I need to move them if I want to use the tanks to spawn something else. The growing fry get moved to larger tanks, usually 10-gallons, but sometimes into larger tanks where I can mix the babies of different (easily separable) species. A few weeks ago I hit the wall on tank space. No more grow out space to move fish into. So I did what any average fish-addicted hobbyist would do… I built a new rack.
Like most fish room improvement projects the end product usually turns out to be a lot more expensive that what was originally planned. My intention was to build a rack that would hold up to fifteen 3-5 gallon plastic ‘shoe box’ bins and five 10-gallon tanks. What SHOULD have cost less than $100 to complete ended up closer to $800. (Don’t tell my wife!) Here is what happened…
The initial construction went as planned. I built a 2×4 rack with dado joints so that the weight of the water is not held by the screws. Making dado cuts without a radial arm saw is time consuming, but the rack is stronger. I was able to knock the rack out in two afternoons at a total cost of less than $50. So far, so good.
Using dado joints may be time consuming, but it is stronger and will support the weight of an aquarium well.
I had enough tanks to put a row of 2.5-gallon and 5.5-gallon tanks on top (I had planned to put bins up there, but the glass was empty), and a few older 10-gallon tanks on the bottom row. I started drilling ports in the air system to run filters in the new tanks and discovered that my 87 Watt linear piston air pump was not up to the job of servicing another two dozen air stones. That pump is rated for 60 outlets. Before starting the new rack I was already running 92. So, in order to continue a new pump HAD to be purchased. I bought the $435 120 Watt version. Oh yeah! Plenty of air now! (Though the checkbook is a little deflated.)
A 120 watt air pump is used to aerate all of the new tanks.
The plastic bins cost $3 each, and I started with ten. The size I bought hold about 3 gallons of water, but the surface area to volume ratio is excellent. Surface area is where oxygen transfer occurs. The greater the ratio, the better the bin or tank is for raising fry. A 10-gallon tank has a 20 sq. in./gallon ratio. My new bins have better than a 50 sq. in/gallon ratio! That means that with my water change schedule (50% every 2-3 days) I can keep as many fry in a 3-gallon bin as I can in a 10-gallon tank. Not bad for $3!
The large surface area to volume ratio in the plastic bins is great for fry since it promotes better oxygenation.
I planned to use some sponge filters I have laying around to filter the bins, but discovered that the filters are too tall. I had to go out and purchase filters with a lower profile. $5 per filter… that’s another unexpected $50 expense. (Do I have to count the cost of the fish I bought when I went to get the filters?)
Ten days after buying lumber I finally had the rack up and running. I immediately transferred the fry from all my 2.5-gallon breeder tanks into bins. Some of the rainbow fry need heat to grow well early in life, and I realized that a submersible thermostatic aquarium heater is probably a bad idea in a plastic bin. My room temperature stays in the mid 70’s (F), but I need to keep those ‘bows up in the 80-82F range.
I settled on trying to use commercially available heat cables that are marketed to reptile keepers. These are rubber-coated wires that do not get hot enough to burn wood or flesh, so they will be safe for plastic. I wanted to put the wire under the bins so the heat will rise into the water, but placing the weight of the water directly onto the wires is not a good idea. To create a gap for the wires I placed three strips of 3/8” thick wood slats under the bins. The wire will run under each bin twice, once in the front and once in the back. I needed two heat cables, one for each shelf of bins, and a rheostat to control the heat of the cables (in case they get too hot). Total cost for all that: about $100.
To avoid having the water crush the cables, the author used pieces of wood on underneath each bin.
In the end: $770
- $50 for lumber and hardware
- $435 for a new air pump (it really blows!)
- $25 for air valves, pvc to extend air system, and other ‘air supplies’
- $30 for the bins
- $80 for three new 10-gallon tanks with glass tops
- $50 for filters that fit
- $100 for heat cables and rheostat
Grow out space so I can continue to rack up spawns and bury Mike: priceless
I am happy with the new bins. The fry are growing fast in them. However, it only took two weeks to end up right back where I started… too many fry and not enough tank space. I need another rack!
Ted's completed DIY fishroom rack, ready to take on more fish!
Posted November 30th, 2009. Add a comment