The Butterfly Goodeid, also called Butterfly Splitfin, used to live in clear, warm springs in Jalisco state, central western Mexico,
but is now classed as extinct in the wild. It has been exterminated by changes in its water quantity (extraction for human use) and quality (pollution).
The male, above, is smaller and more colourful than the female and has a distinctive yellow and black banded tail.
The female, above, looks like a different species, with a dark fleck on a yellowish body and a dark flecked tail.
She is a "live-bearer", ie gives birth to live young rather than eggs. They grow to 8-9cm.
Several zoos, aquaria and even hobbyists worldwide are part of a captive breeding programme to save the Butterfly
Goodeid from total extinction.