Common Name: Olomina
Latin Name: Brachyrhaphis holdridgei
Origin: Central America
Temperature: 74-80º F
Ease Of Keeping: Easy
Aggressivness: Somewhat Aggressive
Adult Size: Females get to a bit less than 2″, with males maybe getting to 1.5″
Minimum Tank Size: 10 gallon
Feeding: They will readily take commercial foods, but really like small live insects.
Spawning Method: A hard livebearer, easy to breed. They will eat their fry though.
© Neil Hinckley Brachyrhaphis holdridgei is the most colorful Brachyrhaphis that I have come across.
It looks very similar to Brachyrhaphis roseni (and goes by the same common name, Olomina), but the colors are more intense, especially on the males. When in good breeding condition, the males got a very nice orange or yellow color cast to their bodies, in addition to their already bright red dorsal fin and dark vertical body stripes. Also, they do not have as distinct of a black crescent on the females anal fins, and the females dorsal fins are not quite as red as roseni. Also, there is a very slight iridescence around their eyes, an almost baby blue color.
It is interesting to note that when I have had a small population of these fish in a ten gallon there has typically only been one really well colored male, with all the rest remaining pale. I am not sure if this is because there are just some males that are more brightly colored than others, or if it is because they establish some sort of hierarchy of dominance in the tank, with the most dominant male becoming brightly colored. In either case there were a few brightly colored males in the 20L that we used to have some in.
The females get to about 2″ with the males getting to about 1.5″. They are also somewhat aggressive. For instance when I had them kept in a fairly high density in a 20L there were a couple Poecilia gilli (a type of mollie) that had made their way into the tank along with them. The gilli were always getting harassed and their fins ended up in shreds (they were removed of course.)
When we first got them in we had no major issues with getting them to adapt to tank life. They were eating flake food immediately after being brought in and allowed to settle for a twelve hours. There was one tank that got a bit of a fungal infection going in it, but a water change and an addition of a little salt (50ml in about eight gallons of water) saw them healthy again in a couple of days, and there were no resulting deaths.
Holdridgei are in the wild insectivores, and so they love a wriggly treat. They are quite fond of Daphnia and fruit flies, and I am sure any other insect or worm, such as blood worms or small beetles. They will eat a bit of vegetative matter, but not healthy plants. All that is really needed to bring out their best colors is some good quality flake food though.
A spanish nome for many of the small livebearers. It means much the same thing as the word “minnow” in english.
Other than that holdridgei are, in my opinion, the best Brachy for the home aquarium. They are colorful, fairly bold, adapt easily to commercial foods, and like most of the Brachys, are easy to breed. They are fry eaters though, so be sure to either have lots of hiding spots or separate out any females that you want to get fry from.