When we first considered keeping Metriaclima estherae I had reservations about including them in the mix. They were candidates because my spouse wanted something that looked like goldfish – for our mbuna tank I did not! As it turns out I had nothing to regret as the velvety smooth coloring of the orange females is unlike the scalier carp-ish appearance of goldfish, and I had the good fortune to locate a reliable source for the blue x red strain.

            Adult female:

 

M. estherae is one mbuna species about which there is much confusion and conflicting information in circulation.  The commonly held view is that in Lake Malawi they consist mainly of blue males and orange females. Orange males and ‘orange blotch’ (OB) fish do occur in the wild, but are rare and belong to the same species. Some sources claim that it is simply a matter of different collection points, and that orange males are found in one location and blue in another, however this view does not seem to be prevalent. The majority of the fish exported for the aquarium trade are collected from the Minos Reef area, where the coloring is said to be most intense.  Fish of yellow or even brownish coloring are reportedly found in other areas, however these less attractive variants are seldom if ever collected for export.

Many photos of blue male M. estherae show the fish with faint vertical barring. Some fine examples do exist of blue males with no visible barring at all though. Here it gets difficult to locate any definitive references as to whether these variants are found sympatrically or at different collection points, however the consensus seems to be that both barred and non-barred blue x red M. estherae hail from the general area of Minos Reef.  I have kept and bred the latter for a few years now and can attest to those I have showing no barring whatsoever, regardless of mood. The ‘red x red’ strain commonly found in the aquarium hobby (where both males and females are orange) has been line-bred from the wild strain in order to consistently produce only orange males. The ‘Cherry Red Zebra’ that has become popular recently is the result of further line-breeding to produce a deeper color of orange bordering on red.

            Adult Male:

Blue males bear a strong resemblance to Metriaclima callainos. Depending on mood the fish’s color can change from nearly white when it is displaying breeding or territorial behavior to the turquoise color typical of M. callainos to a darker grey-blue when in more subdued moods. M. callainos and M. estherae are known to readily interbreed and should therefore not be kept together. Care should also be taken when purchasing blue x red M. estherae to ensure one is not actually getting a mix of M. estherae and M. callainos. For adult fish, features that most easily distinguish blue male M. estherae from M. callainos include a faint orange fringe to the caudal and dorsal fins. An orange hue to the blue coloring of the male M. estherae is also sometimes apparent.

There are many who claim that M. estherae and Labidochromis caeruleus (the ‘Yellow Lab’) should not be kept together either due to a high risk of hybridization. While this cross no doubt does happen I have not yet witnessed it. This is perhaps due to keeping the M. estherae in a good male to female ratio (ie: 1:5) along with a substantial number of L. caeruleus. It may also have something to do with the blue x red (ie ‘wild’) strain itself: male cichlids are often not especially choosy, so unless the fish are kept in improper ratios and/or in too small tanks (where an aggressive male can harass a lone female into submission) in a sense it is the female that ultimately decides if the spawning will take place. If this is the case then it stands to reason that blue x red M. estherae and L. caeruleus kept in proper ratios are no more at risk of hybridization than is normal in general with mbuna, because the con-specific male candidates a blue x red female would normally choose from look nothing like L. caeruleus. The same could not necessarily be said of the red x red strain of M. estherae. Whether line-breeding over many generations to produce orange instead of blue males affects the red x red females’ perception of what their con-specifics should look like is beyond the scope of this article however. Whatever the reason, I have grown on a good number of spawns of M. estherae blue x red and L. caeruleus from the same mix and haven’t noticed anything amiss so far. Of course it behooves me to remain vigilant in case that luck should run out! A sensible precaution, in addition to appropriate stocking and ratios, is to grow the young on to a size of 2” or more before releasing them into the hobby. At that size, some warning signs should become apparent in at least some of the offspring if the fish were cross-bred. (It is also much easier to sell them at 2” or more.)

As juveniles, blue x red M. estherae are easily sexed from the start. Females are a pale orange that intensifies to a rich glowing orange as they grow, whereas males are a dark color (almost black) right at birth. Since orange males do rarely occur in the wild it is presumably possible to have one appear among a brood of blue x red M. estherae in the aquarium, however the rarity of this is such that it can be reasonably assumed that orange fish are females.

           Fry With Yolksacks (tumbled)

As with most mbuna M. estherae will tolerate some deviation from the normal water parameters of Lake Malawi providing the change is not sudden and the water quality is otherwise good. I have kept and bred them successfully in a PH of 7.4. Breeding is typical of mbuna: good water quality plus males and females = breeding. Clutch sizes are in the 15-40 range dependent on the maturity of the female. They are fairly prolific and regular breeders, and it is often possible to sell the offspring to local stores as they have eye-catching color at a young age.

M. estherae is a stout little fish, and in my experience, not one that grows quite as fast or as large as some sources would suggest. While blue x red M. estherae are not exactly ‘slow’ growers, my Labidochromis caeruleus, not known for speedy growth, have kept pace (although the M. estherae are admittedly stockier). My Pseudotropheus acei on the other hand, have rapidly dwarfed the M. estherae, the largest of which (male) is only passing the 4” mark at 2.5 years of age, compared to a 6” P. acei of the same age. I should note that I have seen some red x red male M. estherae that are positively huge compared to my blue males. This could be down to diet or to the individual fish. These examples however, coupled with the general perception of the red zebra as more of a large boisterous ruffian than what I have seen with the blue x red strain, suggests that there may be something more to it. Further sub-speciation not yet fully understood perhaps (hardly impossible with Malwi cichlids)? Or maybe the explanation lies in the fact that most red x red fish in the aquarium trade are descended from many generations raised in captivity on much richer diets than in the wild. For several decades blue x red M. estherae were not imported, in part due to political instability in the area where they are found. Most blue x red to be found in the aquarium trade today stem from recently imported stock, and are not nearly as far removed from the wild as the average red x red.  

Diet-wise M. estherae are generally regarded as omnivorous. They are nonetheless mbuna and the diet should include a decent percentage of vegetable matter. A combination of a good quality pellet and spirulina flakes will do nicely. The occasional treat such as krill (with exoskeleton) is appreciated. As with all Malawi cichlids, land-based protein (eg: beefheart, etc.) is definitely to be avoided!

In terms of aggression this is a fish that holds its own without being a trouble-maker towards other species, in my experience. Just one male M. estherae should be kept per tank unless the tank is very large, and the female to male ratio should be at least 3:1, with 4:1 or 5:1 to one being better. Hobbyists occasionally report rogue males terrorizing their tank, however I haven’t seen this. Those accounts all seem to relate to males of the red x red strain, which may or may not simply be due to there being more accounts of red x red fish to draw on as they are at present still more common in the hobby. For a brief while I observed some spectacular battles between my blue male and my dominant Cynotilapia afra. It was pretty much a draw, neither fish was damaged and peace was restored. The picture below is a fair illustration of how white the male M. estherae can turn when excited.

              Male Sparring With C. Afra

All in all, ‘red zebra’ are hardy and manageable enough for those just starting with African cichlids, yet their qualities will still endear them to the more experienced. They brighten up any tank and mix well with most other mbuna species. The bluex red variant provides the added bonus of giving the appearance of two species in one, and being able to sex the fish right from birth has its advantages as well.