Factsheet 15

Carlhubbsia stuarti. Rosen & Bailey 1959¹

The genus is named after the eminent American ichthyologist Carl L. Hubbs of the University of California. This species is named for Dr. L. Stuart who discovered this and a number of other species. It was discovered in the River Polochic in Guatemala.

This is a fairly easy species of livebearer to both keep and breed. I obtained a pair of these fish in May 2003 and the female was already gravid.

They were housed in a 24 x 15 x 12 tank in hard water at about 21°C. The young were born after a couple of weeks and were in livebearer terms, simply enormous. They were at least twice the size of a newly born guppy. Feeding brine shrimp was almost a waste of time as they needed vast quantities to satisfy their quite voracious appetite. They were able to accept grindal worm and white worm from birth and readily took to chopped tubifex worms. The female of S.L. 25mm. produced 32 fry and these all survived to adulthood. The young fish as expected with the above diet, grew rapidly and were around 20mm S.L. within 3 months. As the males started to develop, they were separated from the females. I believe (with little scientific evidence whatsoever!) that both male and female livebearing fish are more likely to achieve their full potential if raised separately. It is probably all to do with that old, old thing called sex. Those who have difficulty in reading that word have only themselves to blame!! The young fish need plenty of space to grow and frequent water changes are recommended. The female will produce a batch of fry every 4 to 6 weeks. I have found that the gestation period varies slightly – probably because it may be difficult to accurately determine the date of actual conception and to the ambient temperature in the fish house. The largest number of fry born that I have had, currently stands at 43. Adult fish will accept a very varied diet. The whole range of dried, frozen and live foods are all consumed with relish.

Carlhubbsia stuarti is a fairly shy fish and certainly could not be accused of being boisterous. The pregnant females generally do not like being moved to another tank. It is well at home both in a community tank and in a species tank.

   1. Zoologica 44. 5-8.

© Pete Cottle, 2004. This fact sheet may not be reproduced in any form without the permission of the author.