Michi,thanks for the insights. So let's see what will further happen with
P. thermalis.
The species has been 'revalidated' by Poeser 2003, but his reasoning is quite a joke:
This species was not investigated. However, since its type locality describes a
very specific environment, i.e., a sulphurous, hot spring, this species is considered valid as
long as P. sulphuraria (Alvarez, 1948) is also considered valid
The
P. mexicana looks really great. It is beyond me why such jewels are so rare in the hobby, while the shops are full of those unspeakable breeds which look like plastic and are probably not even derrived from pure species. Both
P. mexicana and the true
P. sphenops (in the early hobby literature confused with
P. formosa) have been introduced at the beginning of the 20th century, but since Regan (1906-08) has erroneously synonymized them, they were soon confused and possibly hybridized. Other strains, which would now be referrable to separate species (perhaps even including the sailfin mollies), have further contributed to the 'mishmash'.