by TFH Magazine on May 21, 2010 at 6:13 am
By Ted Judy
Some species of aquarium fish are very well documented in hobby (and scientific) literature, and many, many more are not. What should you do if published advice is lacking? Use the power of observation to help figure out what the fish wants and needs. During the entire process of keeping and trying to breed a fish species, learning from the fish themselves may be the best, if not the only, way to get the clues you will need to be successful.
What do similar species do?
Two species that are in the same genus, or even the same family, will have behavioral similarities. I have kept and bred several species of mouth-brooding Betta species. When I first obtained Betta krataios I really had no idea if there was anything special the fish needed, so I set up a dark tank with lots of hiding places and a tangled mix of Anubias sp. plants and yarn. That is the environment that worked well for other similar species such as B. falx and B. edithae, and it worked well for B. krataios as well.
Observe during the quarantine period.
I use the quarantine period to make some initial observations of the fish. This has proven very useful to me when working with small tetras and barbs. There are so many different species that even some that are closely related will behave differently enough to suggest using a different strategy when trying to breed them. For example, there are two very similar dwarf barbs from West Africa that are hard to find information about: Barbus hulstaerti and B. candens.
I first bred B. hulstaerti and discovered the hard way that in small tanks the males will kill each other. I chose to use a pair-breeding strategy using one pair in a 2.5-gallon tank with a lot of tangled plants and yarn. I was able to get a few eggs from the pair, but not very many because the fish only lays a few eggs each day. When I first obtained B. candens I suspected that they would be the same, but during quarantine I did not see any fighting. I spawned them in the same 2.5-gallon set up, but with a group of 8 fish instead of just a pair, and they produced many more eggs and fry than a single pair of B. hulstaerti did.
Learn the language.
Fish communicate with a combination of color pattern and movement. An observant aquarist will learn to read some of these signals. Females of the Pelvicachromis genus of cichlids, for example, have a specific color pattern for each stage of their reproductive cycle. A courting female looks different than when she is tending eggs, and shows a different pattern when she is guarding free-swimming fry. Once the language is understood a quick glance at a female krib will tell you if there are eggs or fry in the tank, even if the pair is doing a great job of keeping the babies hidden.
Learning the signals a fish gives with color pattern and body posture is also important for the health and conditioning of fish. Most fish have a stress pattern that they express when they are being bullied or the conditions in the tank are not right. There visual clues for disease or poor water quality, such as clamped fins or “scratching,” the flicking of the body against the substrate or an object in the tank. Watching the fish is a part of the fun of keeping them, so a few minutes observing for possible problems should not be a burden.
A short pencil vs. a long memory
They say that memory is the second thing to go. I have forgotten what the first thing is! Taking notes is especially useful when solving a problem through the process of elimination. The first time I worked at breeding neon tetras Paracheirodon innesi I found the eggs difficult to hatch and the fry frustratingly hard to raise. I played with many different combinations of pH, hardness, temperature, food density and light intensity until I found a combination that worked. Had I not taken notes down I would have repeated some unsuccessful combinations.
Taking note of dates is important as well. Livebearing fish have gestation periods, and being able to predict when a female will give birth can prevent babies from being eaten by other fish. When I put livebearers together to spawn I mark the date on the front of the tank, as well as the date of the first possible day fry could appear. That way I know when to separate gravid females into birthing tanks.
Let the fish guide you.
Even when there is a lot of information about a species available to read, sometimes the fish will still surprise you. I have yet to see a fish read the books. The fish will tell us what they like and do not like. All we have to do is pay attention and learn to read the signals.