Text by David Marshall, Ryedale Aquarist Society
Photograph by Arthur Frisby, Wyke Show Society
Ctenopoma ocellatum is endemic to the Congo River system of
Zaire. The first aquarium specimens arrived into Europe at a
time when awe and wonder had not been overtaken by geographical
correctness, so the first labyrinth fish enthusiasts to see
ocellatum linked their amazing cross-striped foreground pattern,
to that of the battle formation of locked together diamond-shaped
shields used by the famous Zulu warriors of Southern Africa
and came up with the common name of Zulu Perch.
Sadly, in modern times, this common name has given way to the
blander sounding Eyespot Ctenopoma (Climbing Perch) in reference
to the ocellus marking at the caudal peduncle. This ocellus
acts to confuse potential predators, as when the Zulu Perch
breaks cover it is hard to tell, in unclean water, what is head
and what is tail.
The Zulu Perch has a very leaf-like body shape (always reminding
me of the ace of spades symbol), moulded by nature to blend
into riverine debris, and uses this to its advantage as, using
the pectoral fins as steering accessories, it will drift through
the water looking like a fallen leaf before suddenly engulfing
unwary prey in the shape of smaller fish species and other edible
foods.
For protection against both predatory fish species and fishing
birds evolution armed the Zulu Perch with an array of spines
that are present on the hind margins of the gill cover (which
is why the Manyspined Bushfish was scientifically named Ctenopoma
multispinis) and please note that these razor sharp accessories
show no respect to human fingers! As an added protection Zulu
Perch tend, in the wild, to live an almost nocturnal lifestyle.
Closely related to the Asian Climbing Perch (genus Anabas)
these fish also have the ability to haul their bodies overland
for short distances, in order to move from one body of water
to another. During my fish studies I have come across no legends
relating to this activity as regards the Zulu Perch but many
such legends and superstitions surround Ctenopoma multispinis.
The people of Zimbabwe believing that this particular fish 'falls
with the rain', basing their beliefs on the fact that it is
not uncommon for specimens to be caught many kilometers from
the nearest body of water in the hours following heavy periods
of rainfall.
The Zulu Perch, which can grow to 15cm, requires a spacious
aquarium with one of 90x30x30cm the minimum size. Remember to
follow the airspace rule for labyrinth fish, leaving a space
of 2.5cm between water surface and condensation shield, as deprived
of the chance to gulp at atmospheric air the Zulu Perch are
unable to maintain their labyrinth organ in full working order
and thus effectively drown (many a Siamese Fighting Fish, Betta
splendens, has been lost in aquaria due to this reason). The
Zulu Perch will do well with a pH of 7.5 and a temperature of
25 C.
From both my own experiences and those of fellow labyrinth
fish enthusiasts it is clear that not all Zulu Perch share the
same need to seek shelter. Some will only be truly happy when
provided with places of concealment, in the form of tall plants
and large pieces of Mopani wood, whereas others prefer to stay
in open water at all times. Thankfully, and unlike some other
members of the Ctenopoma genus, the Zulu Perch does not have
a reputation for doing death leaps from aquaria, although a
tight fitting lid should be employed in order to prevent any
such potential escape acts.
Feeding this particular specie is never a problem - in fact
some, in particular females, will gorge themselves into a state
of obesity if given the chance. Commercially produced aquarium
flakes and pellets, pieces of Thai crabstick, prawns and diced
carrot are all taken with equal gusto.
Although they will make an extra meal of any other fish small
enough to fit into their mouths, the Zulu Perch can be kept
alongside large Barbs (in particular Tinfoil's), Silver Dollars,
Oreochromis species, large loricarins and Synodontis catfish.
Once settled in such company they tend to relax any nocturnal
activity and can become very outgoing. In lightly stocked aquaria
this can, on occasions, cause problems as the Zulu Perch, in
particular lone females, have the ability to 'take control'
and when this occurs will pick out individual tank mates to
nip and chase causing as much psychological as physical damage!
Please remember that all Ctenopoma can be extremely long lived,
with many records existing of those which have lived in excess
of 20 years, so please give thought to this before making a
purchase as Zulu Perch (like Koi and Osphronemus) need to be
with aquarists committed to their long term care.
What we know about the reproductive aspects of these fish is
that, at maturity, males often develop small spikes on some
of their scales. Females are more rounded in appearance. During
spawning no bubblenest, as is the case of their Microctenopoma
cousins, is in evidence and as the female releases her eggs
these are fertilised by the male and float at the water surface.
Sadly, although this fish is now commercially produced, we have
no published accounts of a successful aquarium spawning to refer
to
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