|
Home | Marine Aquariums |
Freshwater Aquariums |
Planted Aquariums |
Brackish Systems |
Ponds,
lakes & fountains |
Turtles & Amphibians |
Aquatic Business |
Aquatic Science |
Ask the WWM Crew a Question |
Please visit our Sponsors | ||||
During the discussions leading to this
article, I enquired of your Editor how he would define dwarf mbuna,
especially what upper size limit. 'Dunno, you're the
cichlid expert, I leave that sort of thing to you.' Editors
are so helpful!!! But I think establishing what we're talking
about is a good start here, as I personally wouldn't regard any
mbuna as dwarf cichlids in the usual sense, hence my original
enquiry. Many years ago I attended a lecture on dwarf
cichlids by Paul Loiselle, in which he defined a dwarf cichlid as
follows:
1)
Maximum (total) length 4
inches;
2)
Peaceful enough and otherwise suitable to be kept and
bred in a general community tank. OK, so point 1) gives us a starting point on
size, but where 2) is concerned we can immediately strike all
mbuna. And Paul in fact went on to say that his definition
immediately ruled out everything from Lake Malawi and Central
America. That was in 1981, and although I know that a number of
small mbuna, smaller than anything known back then, have been
discovered since, I've not yet seen any reason to argue with his
statement. It is possible to keep a single adult mbuna of some --
even most -- species in a general community, but the moment you add
another one, same species or different, trouble is likely to break
out.
So, regrettably, we can forget about the
conventional concept of a dwarf cichlid when defining dwarf
mbuna. We are instead really looking at smaller than average
mbuna. How small?
Four inches TL is nevertheless a reasonable
'cut-off' point for defining dwarf mbuna, as we need to
establish some sort of size delimiter. The next question is, however, are we
looking at normal, natural (wild) size or aquarium size? Wild
mbuna have quite tough lives, they have to survive on an often
impoverished diet, and they get a lot of exercise moving around feeding
and darting away to safety when they accidentally stray onto the patch
of an aggressive territory-holder, which happens all the time.
Sometimes they have to contend with strong currents or other turbulence
which make swimming hard work. By contrast, tank-bred mbuna have it
easy. A rich (usually too rich) diet is delivered frequently
(usually too frequently) by a doting owner, and instead of feeding all
day they get rather more than the food they actually need in a few
short sessions. Once they have settled down and established a
'peck order', there isn't generally too much chasing except
when a female is ready to breed. So all that food is converted
into growth. Not only that, but over generations of
captive breeding mbuna tend to become less aggressive. This is
probably because killing your female(s) is not a good survival
characteristic; so while a powerful male, able to hold territory
and thus get to breed, is at an advantage over weaker males in the
natural habitat, the reverse is true in captivity. It is rare for
a captive male to have to compete for females against conspecifics, we
usually keep just one male, to avoid constant warfare. So the
less aggressive male who doesn't regard unripe females as enemies
on his patch is at a genetic advantage in the aquarium.
The result is couch potato males that can
achieve a length significantly greater than their wild
counterparts. To take one example, Metriaclima
estherae, the Red Zebra. This fish can easily attain 4.5'
TL in captivity, but although I've handled about a hundred caught
at random for genetic sampling (fin clips) at Minos Reef in Mozambique,
not one was more than 3' long. The first imports I ever saw,
back in the 1970s, were more like 2.5'. Wild M. aurora
(also sampled) never exceeded 4'. But how many of us think of
any Metriaclima as a dwarf?! Then there is Metriaclima lanisticola
(still better known as M. livingstonii), which has a long
north-south range and measures about 3' maximum in the north
increasing to 6' in the south. What are we to do with that,
especially as the small-size populations seem to be more aggressive
than the large ones! The whole thing can also work in
reverse. Repeated brother-sister matings over many generations
can lead to a reduction in size, often with other 'faults' such
as melanism thrown in. We don't see too much of that though,
as serious hobby breeders know better, and most tank-breds are
farmed. But I have seen Labeotropheus fuelleborni reduced
from their normal 5-6 inches to less than four, black, and blind after
six generations of non-selective inbreeding. Such fishes are not
dwarf mbuna, they are abominations and you really don't want
anything to do with them. So, returning to the question of the size
limit for 'dwarf', I think the answer is to look at wild size,
as otherwise I'd have to rule out practically every known species,
and the few that remain may well rule themselves out after a few more
generations of the good life in captivity. Small is not always peaceful
So, what can we expect of our dwarf mbuna in
terms of behavior? Does their small size mean they are less
aggressive than the larger species? The answer, as with so many things cichlid,
is yes and no!
Size is never a reliable indication of
behavior where cichlids are concerned, and although Kribs
(Pelvicachromis pulcher) are generally regarded as dwarfs, I
would observe very carefully any community into which I had placed
them, having seen one pair keep six four-inch Uaru (Uaru
amphiacanthoides) confined to one upper corner of a 48'
aquarium and take turns to go over and issue reminders. By the
same token, some quite large or even very large cichlids can be
ludicrously peaceful. My Uaru didn't even try to fight
back! Temperament in fishes (and other animals) is
normally inherited and evolves to match environmental pressures.
Thus a cichlid that doesn't have to compete much for food and space
in the wild is liable to be peaceful (except maybe when defending
young), while one that has to fight tooth and nail to survive is going
to have an aggressive, territorial outlook on life. As most
Malawi enthusiasts will know, the amount of rocky habitat in the lake
is limited and occupied by a high population density of mbuna which
apparently have a psychological inability to cross sand or mud to find
somewhere less crowded. Hence wild mbuna are in the main
competitive (= aggressive), and even when this survival characteristic
has been reduced by the aquarium good life, there is still enough of it
left such that they can never really be termed peaceful.
Small cichlids from a competitive
environment often come with 'attitude', just like small people
do. They are at a size disadvantage when it comes to holding
their own, so they are often territorial out of proportion to their
size. It is a big mistake to assume that smaller means more
peaceful. This is probably why we see 'inverse
territoriality' in the species I mentioned earlier, Metriaclima
lanisticola. The small populations come from relatively
highly populated habitats, the largest come from the small Lake Malombe
south of Lake Malawi, where there isn't much competition at
all. Cynotilapia look like small Metriaclima
('zebras') but in my experience a 'Cyno' can see off a
Zebra without problem, even though larger size is often a deterrent to
attack! Of course, because they are cichlids and
their role in our lives is to confuse and cause us problems, there are
also small mbuna that are peaceful, eg Labidochromis. To
sum up, never make any assumptions regarding behavior based on size
alone. It is probably safer to assume small means stroppy if your
'homework' before purchase doesn't reveal anything on
character. Having established what we are talking about
under the heading 'Dwarf Mbuna', let us now look at some
individual genera that contain such fishes, and some of the relevant
species they contain.
Cynotilapia
Members of this genus 'top out' at
3.5-4' in males, with females usually smaller. As already
mentioned, small does not necessarily mean peaceful, and
'Cynos' exemplify this. They are plankton feeders in the
wild, but because territorial males are highly possessive of their
domains they have 'algae gardens' -- ungrazed areas of algae --
around their caves. That means they are successfully seeing off
even much larger algae-feeding mbuna such as Labeotropheus and
Petrotilapia - no mean achievement. Non-territorial males and females are
usually found in shoals where the food is; but trust me, the
moment you give a non-territorial male the opportunity to be
territorial in your tank, he is going to grab that opportunity.
These are gorgeous little mbuna, but they are more suited,
temperament-wise, to a tank of larger mbuna of similar
disposition. They are more than able to look after
themselves. Iodotropheus and Labidochromis
Members of these two genera are among the
most peaceful of the mbuna. Males don't hold permanent territories
where females will know where to find them when ready to spawn; as far
as I know it's simply a hit-and-miss case of 'boy meets
girl', and if girl is ripe, they spawn. This is a very
different lifestyle to most mbuna. Their feeding strategy is also
important. Because they require no breeding territory, they move
constantly around the rocky habitat and are apparently rarely attacked,
probably because they are recognized as harmless non-competitors.
Most Labidochromis species feed by winkling invertebrates out of
cracks, and have thus found a specialized feeding niche with little or
no competition from other mbuna species. They are often found in
large caves -- not the habitat of the algae-grazing mbuna, so again
less competition. The algae-feeding Labidochromis are
more difficult to explain. We do not know which feeding method
came first, but my guess is that the algae eaters evolved from the
insectivores. Their niche is an opportunistic mouthful of algae
here, another there, as they wander through the habitat. It is
easy to see how this behavior could have developed, maybe when insects
were short supply, and would not provoke attack from territorial
herbivores used to 'Labs' just 'passing
through'. Iodotropheus
are also algae-feeders but again do not stop long enough to cause
offence to any territory-holder. Perhaps they evolved a mobile
way of life because they were unable to compete effectively for
territory, as both known species (sprengerae and
stuartgranti) have very limited distributions and may be
survivors of once more widespread species that have been outcompeted
elsewhere. Aggression is neither necessary nor
desirable where there is no competition and no need for defense; if you
rely on being harmless to earn your living, picking fights would not be
a survival characteristic. Melanochromis
Members of this genus generally have a bad
reputation for being hard on females, but there are in fact several
small species that are not in that mold. These include the
well-known M. joanjohnsonae and what I term the M.
johanni group -- johanni, interruptus,
cyaneorhabdos. The latter three are smaller
and more peaceful than most of the genus and the first two of them have
orange rather than banded females. I am convinced that they are
actually members of a separate genus (or genera) as although they
conform to the current definition of Melanochromis, the
horizontal bands are in quite different positions to in M.
auratus, for example. I don't think joanjohnsonae
belongs in the genus, either! M. dialeptos is also smaller
than my 4' limit and looks very much like a small
auratus. The territoriality of these species seems to
be variable -- I have read in several books that johanni
isn't territorial, and mine were quite peaceful, but I have watched
some real battles between males in the lake. Answer, keep one
male and nothing else with a similar provocative stripe pattern, as
with all banded Melanochromis. Metriaclima
The majority of the members of this genus
are far too big to fall into the dwarf category, but a few do, notably
M. sp. 'membe deep' from Likoma, and M. sp.
'msobo' and M. sp. msobo heteropictus' from the
Tanzanian shore of the lake. The 'Membe' is really small
(three inches in males, one of the very smallest mbuna) There is a
question mark over whether these three belong in the genus at all as
their coloration isn't at all characteristic, and some authors put
them in Pseudotropheus (where they certainly don't belong,
see below). They are territorial like other Metriaclima
and tend to 'attitude'. As mentioned earlier, some other
Metriaclima also conform to the size limit when wild-caught, and
in my experience are relatively peaceful, more so than the three listed
here. Pseudotropheus
Pseudotropheus
is polyphyletic, in other words its members are not all descended
from a single species as the definition of a genus requires; this
is scientifically recognized and hence the genus is slowly being broken
up into separate genera. At present it contains a large group
known as the 'elongatus group' (all elongate and
slender) and a lot of 'odd' species whose generic status is
largely a mystery.
The elongatus group contains a fair
number of dwarf species, mostly undescribed, the best known being
Ps. 'elongatus ornatus' or just 'ornatus' and
Ps. flavus, better known as Ps. sp.
'dinghani'. The group comes with a big 'but' -- I
am convinced that these elongate mbuna are not all closely related and
probably belong in at least two separate genera. In my experience
those with no bars between the eyes grow larger and are considerably
more aggressive (sometimes downright murderous) than the smaller
species with interorbital bars and a fairly civilized
temperament. So while there are 'dwarfs' here, don't
make any rash assumptions on the basis of the
name. One of the best known and most popular of
the 'oddments' is Ps. demasoni, a true dwarf that
attains only about three inches. It is non-territorial in the
wild, though may occupy territory if given the opportunity (no
competition to keep it in its place) in captivity. This is,
however, perhaps the only species that can be termed a true dwarf in
the traditional sense of very small and peaceful. The genus contains a number of other species
of similar small size - for example Ps. minutus, Ps. sp.
'polit', Ps. pulpican, and Ps. saulosi -- but
less equable temperament, ranging from rather to very
territorial. Ps. pulpican
deserves a special word of explanation. You may also
find this species as Cynotilapia and Pseudotropheus in
the literature, and the species name will probably mean nothing you at
all until I tell you that this is the little cichlid we have known for
decades as Kingsizei! It looks like a Cyno, feeds like both a
Cyno and (mainly) a 'zebra', and its teeth don't fit with
either. Moving up slightly in size we have Ps.
heteropictus (3.5', aggressive) and the well-known Ps.
socolofi (4', rarely aggressive). Tank-bred Socolofi
are, of course, significantly larger, but usually peaceful compared
with many smaller species. In conclusion
So where does all this leave us? Well,
essentially dwarf mbuna aren't substantially different to other
mbuna, they are just smaller. They may well be over-aggressive
for their size, and need just as much space as larger species. So
if you were dreaming of a 24' mbuna community filled with peaceful
dwarf species, please forget it!
References
Konings,
A. 2003 Back to Nature Guide to Malawi
Cichlids (2nd edition). Cichlid Press, El Paso, USA.
208 pp.
'
' 2007
Malawi Cichlids in their Natural Habitat (4th edition).
Cichlid Press, El Paso, USA. 424 pp. |
|
Features: |
|
Featured Sponsors: |