Why Loaches Should Not Be Kept With Malawi Cichlids
A question that is asked time and again on the Loach forum is “Are loaches suitable for keeping with Malawi cichlids?”
This is usually with reference to the larger Botiine species, such as Clown Loaches (Chromobotia macracanthus), several species from the Yasuhikotakia genus (such as Y. modesta and Y. eos), in addition to those loaches from the Syncrossus genus (which are largely referred to as the ‘Tiger Botia’ group).
All too often, unscrupulous shops and misguided cichlid websites will state that the practice of keeping these two very different types of fish together in the same aquarium is acceptable. It is not. In this short article we aim to provide detailed information as to why the combination of these two types of fish is totally inappropriate.
Botiine loaches hail from fast flowing rivers and streams in Asia. The currents they encounter are primarily uni-directional and rather forceful, and the water parameters are soft and acidic. In some locations, for example, in some parts of Kalimantan, Clown Loaches can even be found in areas of blackwater, where waters are extremely acidic and with an almost undetectable hardness.
Conversely, Africa’s Lake Malawi has a very hard, alkaline composition. The average pH value of the lake is around 8.3, with an average hardness reading of 18dH. Forcing fish, that have evolved over thousands of years of living in a certain set of conditions, to live in conditions considered to be at the ‘other end of the scale,’ can have drastic effects on their osmoregulatory systems.
The temperature of the water in Lake Malawi varies throughout the year, with the average reading being 25oC (77oF). This is considered to be at the lower end of the temperature range to which many Botiine loaches are accustomed to. If you attempt to keep the Malawi cichlids at a temperature which suits the loaches, the cichlids may well suffocate. If your loaches are kept at lower temperatures, they could become even more stressed and therefore more susceptible to disease problems such as whitespot.
Lake Malawi is much larger than many people envisage, and it does have a certain amount of gentle tidal activity. However, the continual forceful one-way current found in the natural habitat of the streamlined Botiine loaches is not present.
Whilst they do consume a certain amount of green foods, the natural diet of Botiine loaches mainly consists of ‘meaty’ foods such as insect larvae, worms, and crustaceans. Malawi cichlids have adapted to eat the food that their environment provides, and in the aquarium, will eat it even if it is actually unsuitable for them. Many are herbivorous, and whilst some can be fed on crustacean based foods every now and again, mosquito larvae and worms (which loaches so relish) cannot be fed to the cichlids without causing them major digestive problems, such as ‘Malawi bloat’ which can be fatal.
Malawi cichlids are notoriously aggressive and should not be housed with other fish types, despite any examples you may have seen where other species have been forced to live with them in the confines of an aquarium. Some species of Malawi cichlid are less aggressive than others, but this lower level of aggression is still greater than what loaches should have to constantly live with, and which they would have no real escape from. As the cichlids reach sexual maturity, the aggression level heightens, and sensitive species such as loaches will not cope well with being exposed to this for any great length of time. They will be barely surviving in a permanently stressed out state, and are likely to succumb to whitespot or even physical injury. This even applies to the feistier loach species such as the Tiger Botia, whose aggression level, whilst considered high for a loach species, is no match for the relentless belligerence of Malawi cichlids.
Loaches like to have multiple hiding places within the aquarium in the forms of bogwood roots and cave piles made from inert rocks. Malawi cichlids also like a good deal of rock cover, but they are well-known diggers and can excavate large areas of substrate from beneath cave structures, leaving them very unstable. I don’t need to spell out the potential disasters that could occur.
One last thought. As mentioned earlier, the fish concerned have evolved over thousands of years to adapt to certain set of conditions. A handful of generations of breeding is not going to change thousands of years of evolution. You may see/hear of fish temporarily surviving in 'compromised' conditions, but their long-term health is likely to suffer. Mankind should not force fish to adapt to what we want, and keeping fish in such an unsuitable environment does not make anyone a better fishkeeper for ‘getting away with it’. The aquariums that we keep them in should first and foremostly be tailored to the fishes needs, not ours.
Further reading on osmoregulation and osmotic shock is highly recommended.