Factsheet 9

Macropodus erythropterus. Herder & Freyhof. 2002¹

The genus Macropodus has, after many years virtually unchanged, recently undergone some revisions and additions. Previous to the changes, there were, apparently three species; M. opercularis (the common paradise fish seen in many tropical fish outlets), M. ocellatus (once known as M. chinensis; a very hardy species capable of living comfortably in temperatures down to about 5&degC) and finally M. concolor, the black paradise fish.

The fish known as M. concolor is now understood to actually represent two species and as such the concolor name no longer applies, instead the two species are each known correctly as M. hongkongensis and M. spechti. A further new species is now described from Vietnam and is the subject of this article; “Macropodus erythropterus”.

My trio of Macropodus erythropterus were brought over from Fischhaus Zepkow in Germany by Pete Cottle & Pam Boyle, along with another trio that were promptly delivered to Andrew Smith of the AAGB. Both sets of trios were reasonably sized, immaculate fish and would be ready to spawn once settled down after their long journey.

My fish were placed in a 28 x 12 x 15 inch tank containing about 10 inches of water at a neutral PH. The tank is filtered by a large sponge filter set to run as slow as possible to minimise surface movement, no substrate is used and the tank is a mass of plant, mainly wisteria, java moss and hornwort which is left to float. Two plastic pipes were placed on the base to provide a refuge for the females.

The fish were fed tubifex, white worm, frozen bloodworm and flake and it was not long before one female was full of roe. The male initially built a magnificent nest, about 3 inches across and an inch high. He constantly kept adding bubbles to his nest, but could not coax the female into spawning, it was not long before he lost interest in his nest and it soon disappeared.

After about one month with no renewed activity, I floated a 6 inch square of polystyrene at the rear of the tank in the hope that this would encourage him to try again. The polystyrene did the trick and a new nest was built beneath it. Two days later I observed the female taking an interest, the male allowing her near the nest for the first time since its completion. Another two days passed before the spawning commenced, the male embracing the female until the eggs floated to the surface, many missing the nest completely. It was difficult to determine the number of eggs produced, but there were plenty!

I decided to remove as many eggs that had missed the nest as possible in order to hatch them in a separate tank, thus providing a safety net should the male eat the eggs or emerging fry. The slightly amber coloured eggs, measuring about 1mm were laboriously scooped from the surface using a 5ml plastic medicine spoon. This proved quite difficult as it emerged that the male would guard his eggs in the most ferocious manner! He constantly scanned the surface of the water, waiting for the spoon (or my hand!) to be within striking distance and then would leap from the water and take a “bite” at his target. Subsequently, both lots of eggs hatched and were successfully raised.

The eggs that I had removed were placed in an old show tank using water from the parent’s tank. At this stage I added a few drops of liquifry in the hope that it would produce some infusoria ready for when the fry needed to feed.

The first fry emerged after 48 hours, measuring approximately 3mm; they spent the first part of their lives floating upside down, their large buoyant yolk sac hindering their efforts to move around. After a further 48 hours, the yolk sacs were all but gone and feeding commenced. A combination of microworms and Liquifry were used for the first four days, and then the liquifry was replaced by powdered flake, pre-soaked to sink.

As the fry grew, the size of powdered flake was increased and other dried foods including high-protein granules were crushed and mixed in with the flake to provide variety. Frozen artemia, Cyclops and daphnia were also used.

At about three weeks the biggest fry had reached 5mm and some were seen to eat white worm provided for the parents! At six weeks, some fry had grown to 10mm and had evolved into little miniatures of their parents.

While I had intended keeping the PH at neutral it did “crash” down to 5.0 with absolutely no ill effects noticed on either adults or fry, proving that they do not seem to be fussy as to water parameters.

In conclusion, this species is proving to be easy to keep, breed and rear. I do not think that the species will become very popular amongst fish keepers in general as it is an aggressive species and to some, may not seem too colourful, although in my opinion, the fish is an attractive species, and well worth the tank space.

A review of the paradise fishes of the genus Macropodus in Vietnam, with a description of two new species from Vietnam and Southern China. (Perciformes:Osphronemidae).

   1. Ichthyological exploration of Freshwaters 13: pages 147 to 167

© Mark Nazer, 2003. This fact sheet may not be reproduced in any form without the permission of the author.