Peociliopsis turrubarensis

Common Name: Olomina
Latin Name: Peociliopsis turrubarensis
Origin: Central America
Temperature: 74-82º F
Ease Of Keeping: Easy
Aggressivness: Not Aggressive
Lighting: Any
Adult Size: Males to about 1.25″, females to almost 2″
Minimum Tank Size: 10 gallon
Feeding: Will take commercial foods, but likes vegetables as well.
Spawning Method: An easy to breed livebearer. They will not normally eat their fry, though good cover helps.

Peociliopsis turrubarensis is a medium sized livebearer with a few interesting attributes. First of all, it bears it’s young in the same manner as one of the smallest livebearers, Heterandria formosa, called superfetation.
The simultaneous development of several broods within the ovary. Also spelled superfoetation.

However, they probably do the same thing for different reasons. While Heterandria formosa probably undergoes superfetation because of its small size, it is thought that Peociliopsis turrubarensis uses superfetation in order to maintain a competitive advantage. Because there are smaller broods that approach maturity at smaller intervals (usually about 2-5 fry every week to week and a half) the overall volume of the mother doesn’t vary much. This means that, unlike many of the other livebearers, the mother turrubarensis is just as fast when she is about to give birth as she is just after giving birth. It seems to me that turrubarensis fry are also a bit bigger than some of the other similarly sized livebearers, but as far as I know no actual research has been done to verify this. Also, because they have so few fry at a time they are less likely to eat their own fry. If the tank is heavily populated they get eaten, but as long as there is some cover and not too many adults the fry are relatively safe. Because of their small, frequent broods and their body color it is pretty much impossible to tell when these fish are pregnant.

Turrubarensis are not a showy fish, but they have a very streamlined shape, and in good conditions and with bountiful food they have a bright purple or blue ring around their eyes, as well as a purple sheen and dark vertical bars on their sides. The bars are most obvious in their fry, while they don’t usually get the iridescent ring around their eyes until they reach about a half inch in length. The females can probably get to almost 2″ in length, with the males getting to maybe an inch and a quarter.

Peociliopsis turrubarensis usually lives in estuaries and similar areas and so is used to, and likely prefers, having some salt in the water. I have kept them in just tap water and also in tanks with some added salt (usually about 50-100ml/gallon, so not much salt.) They have done well in all of these conditions. In fact these fish are similar in many ways to mollies. They like salt water, and live vegetative matter better than insects. In fact, in my experience they are very reluctant to take live insects such as fruit flies, preferring instead algae and algae flakes. The tank that they seemed to do the best in was a 20L that had heavy cover on one side (a ton of large plastic plants set in a little bit of gravel and long enough that they also covered about half of the surface of the tank.) This tank was allowed to develop green water, and the fish really seemed to thrive in it. Eventually some of the dead algae collected in the little bit of gravel in the tank and began to rot, and this caused the fry to have a hard time surviving in the tank, but the adults did just fine. With a little bit better maintenance I bet that this setup could be maintained indefinitely and it is a great way to breed the fish.

The fish that we brought in from Costa Rica had a number of babies in transport, and the vast majority of this young fish survived and were successfully raised to adulthood. Some of the adults had black spots on them, somewhat larger than ground pepper. These were a harmless nematode that have mostly dissapeared by now. The wild fish quickly adjusted to eating flake food, though they certainly don’t eat it with the same vigor that some of the other fish eat it. They do live to have some vegitables in their diet, and they also seem to do a bit better at temperatures in the upper seventies to around eighty.