The amazing number of guppy varieties available for the aquarium today is almost unending, with new colour combinations, and finnage developments coming on stream to the aquarium market regularly. The large bodied, extravagantly finned, intricately coloured specimens are so far removed from their tiny, but very pretty, wild relations, it is difficult to appreciate that they are indeed from the same roots. Some of the former hardiness has certainly been lost in this evolutionary process, but in general guppies remain easily kept, undemanding, aquarium fish.
There are few aquarium fish that share all the virtues of the platy fish. The “moon” platies are available in an amazing range of colours and colour combinations. Some have finnage development to add to the enhancement of their overall appeal. A naturally placid, tolerant, nature is a valued quality. The “variatus” platies are often less reliable regarding their temperament, but share all the other qualities of the “moon” platies otherwise, and tend to have more streamlined bodies, compared to the plump profile of their “moon” cousins.
Of all the live-bearing fish in the hobby, the Swordtails have a special appeal. Probably to do with the impressive but manageable size, or maybe more so due to the stylish extension to the male’s caudal fin, which gives the species its common name. Like the Platies, Swordtails have been developed with a huge range of colours, and finnage variations. There are Hi-fin and lyretail versions within the range of colour forms and combinations. Some males can be boisterous, but with a good diet, enough space, and more than one female to court, the risk of this vice can be reduced significantly.
The Mollies have been developed way beyond their natural forms, except it is true to say that there are natural sailfin species to be found in the wild. However domestic line-breeding has worked to emphasise this magnificent feature. The fact that Mollies will tolerate being kept in full-strength seawater is an indication that at least some salt content in the aquarium water is often necessary for their well-being. Without it “Molly spot” fungus outbreaks will often invade the bodies of vulnerable strains. Some varieties are more susceptible to this condition than others.