Info on Halfbeaks:
From Scott, Peter W (1988, 1997), A Fishkeeper's Guide to Livebearing Fishes, Tetra Press, China.
(I rephrased or made syntax changes when the author referred to information in previous paragraphs referring to other species)
The Hemirhamphidae or Halfbeaks are fairly widespread in the streams and ponds of Southeast Asia and the Malay Peninsula (p.14)
Some species of livebearers seem to prefer to be alone while others prefer company. Mixing genera of the smaller species seems to work well. For example, Quintana atrizona or Priapella intermedia mix well with Heterandria formosa. Demogenys (Halfbeaks) also prefer the company of other species (pp.19-20)
Halfbeaks find [aquarium] salt beneficial, especially for breeding. The usual amount added is 0.5 - 1.5mg/l (half to one and a half teaspoon per gallon). If more than this is used, plant growth can be inhibited. (p.24)
Most plants are fairly happy in the moderately hard, mildly alkaline water of livebearer aquarium. If the water is slightly saline to suit the more delicate Mollies of Halfbeaks, a number of plants can be acclimatized to living in [low-end] brackish water. It takes a few days of building up the salt level. Some browning of the leaves will occur, but the plants will settle down. (Author recommends Vallisnera spiralis, Valisnera tortifolia). (p.30)
Halfbeaks are "one-sided" with their modified anal fin being referred to as the andropodium. The
gonopodium bends to one side and the male can only mate with a female with a genital opening inclined to the opposite side. That is a right-handed male mates with a left-handed female. (p.36)
As for food I found no specific info for Halfbeaks in the book so I figure you should post your experience so we all learn from it.
Halfbeaks (and Poeciliids) can store sperm, so that one mating can provide enough for brood production over a period of several months. (p.40)
Pepetj
Santo Domingo
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