uite a number of articles have been written over the years about
Hoplosternum pectorale - the smallest of the three species
of Hoplosternum. However having kept this fish for about
five years, spawned them and their offspring on many occasions
I feel some of my observations may be of interest.
H.
pectorale when full grown is about four inches in
length, colour varies from dark tan to almost nigger
brown with darker spots.
I feel that water conditions probably influence the
intensity of colouring. Males are often slightly darker
than females with much thicker rays on the leading edge
of the pectoral fins - these rays are curved in both
sexes but the curve is very pronounced in the male,
also, as well as having thicker rays in the pectoral
fins, males have more colour in them, sometimes they
are almost orange and whereas the rest of the fin is
clear in the female nearly all males have a white mark
in the middle of the pectoral fin. When viewed from
above in a shallow dish these characteristics are very
easily seen.
This fish is a very
efficient scavenger and pokes its long barbels into
all corners for food,it being omnivorous and will accept
almost anything you like to offer. It is also adept
at folding back the barbels and digging well down into
the gravel for Tubifex. Incidentally all my catfish
(Corydoras and Hoplosternum) are kept on sharp
quartz gravel and I have never had any damage to the
whiskers.I am convinced that any barbel damage to catfish
is caused by adverse bacterial conditions. One more
point, H. pectorale would appear to be very useful
for the eradication of Planarians - more than 1 can
say for Corydoras. Now for spawning this interesting
fish, a very interesting event - all one requires is
a pair of the fish and a small polystyrene meat dish!
First of all prepare the dish - these are usually about
half an inch deep - by trimming off about an inch all
round this leaves the tray about an eighth of an inch
deep. A spawning tank can be prepared (18" x 10"
x 10" will do) but this is not necessary as the
fish will oblige in your community tank.
Feed the fish well (I use tinned dog food and Bemax
mixed together and fed at night). When the female looks
nice and plump - the lateral line becomes more pronounced
when she is - put the polystyrene tray in the tank face
down and within a few hours the male will have found
it and started a bubble nest. The nest is made by taking
in air at the surface and expelling it under the tray
at the same time beating it into small bubbles with
the pectoral fins. You will now get the idea of the
edge on the tray as it holds the nest together.Incidentally
nest building is accomplished in an upside down position
and I am almost sure that when in spawning condition
the male gets darker on the ventral surface. When the
nest is almost complete you will start to hear grunts
and burps - audible some distance from the tank - from
the male. When the male has finished the nest the female
will start to take an interest in it and will start
to do dummy runs through it - upside down like the male
pressing herself against the.'roof' meanwhile the male
circles around underneath. After a while - presumably
when she thinks everything is to her liking she will
approach the male and start to nudge him and they will
circle around under the nest. In due course they will
assume the 'T' position with the female's mouth at the
male's vent - I have a feeling she may actually take
a ventral fin into her mouth - she then swims a short
distance away and will rest in the plants for a few
moments and then return to the nest at which stage one
or two eggs can just be seen held in her ventral fins.Inverting
herself she now ploughs through the nest and applies
the egg or eggs to the polystyrene hood, once this has
been completed the 'T' position is resumed as soon as
possible and the whole process is repeated many times
until up to two hundred eggs have been laid. On one
occasion when two females were ready together they both
spawned with the male simultaneously.Once spawning is
completed the female goes back to the bottom of the
tank and the male takes up position under the nest to
keep it topped up with bubbles and also guard it, put
your finger in the tank at the edge of the nest and
you will be surprised at the punch he can pack! The
eggs when first laid are pale flesh colour about pin
head size.
Depending on temperature they will hatch in four to
five days during which time they will get darker and
are dark brown when ready to hatch. If your fish are
in the community tank this is the stage to lift out
the nest - mind your fingers - and float it in another
tank to hatch. If you have the fish in a spawning tank
- the female having been removed after spawning - the
male can be left until all the eggs have hatched and
the tiny fry fallen to the bottom of the tank when he
can be removed. The fry when first hatched look like
eighth inch long dark brown tadpoles and will immediately
hide themselves in various corners and under larger
stones. Feeding is the same as for Corydoras fry
and with good feeding the fry will reach half an inch
in six to eight weeks. Incidentally I have seen it recommended
that raising the temperature to 80oF induces spawning,
this I agree with for controlled spawnings but my adults
have spawned at 75oF in the community tanks. Incidentally
if my adults have spawned in the community tank I have
lifted the nests out to hatch in other tanks that I
have fry of other fish in and have found this quite
successful. 1 have purposely not mentioned water conditions
as in my area, Greenock, Scotland, tap water is useless
for fish breeding being heavily dosed with alumina to
precipitate out the peat stain. I therefore have to
top up my tanks with rain water adjusted with bicarb
to neutralise the acidity - things are not easy here.
Suffice to say 1 think Hoplosternum likes the
water slightly on the acid side. I hope this article
will tempt others of you to try this interesting and
to me - easy fish.
This article first appeared in the
Catfish Association of Great Britain Newsletter in 1986.
(Editor) Since this article was
produced, pectorale is no longer in the Hoplosternum
genus and now goes under the name of Lepthoplosternum
pectorale with five other species, beni,
altamazonicum,
stellatum, ucamara and tordilho.
