your internet guide to all things catfish
by D. O. Carr
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
If you would like to contribute an article, please e-mail me. You will of course be credited for your work.
If you would like to donate any denomination of money to the site just click the above link button. All proceeds will go to running the site and hopefully to keep it going for a few years yet.
Print or e-mail this factsheet below