They are called chromatophores, I think.
> >
> > I have some Boesmany and the vertical dark stripes that
> > separate the front and back fish colors sometimes flash
> > sequentially like a marquis neon sign.
> >
> > <snip> I noticed my some of my praecox sometimes light a
> > >yellow stripe along their back. They can light this on
> > >and off quickly <snip>
This phenomenon is present in other puddle fishes of totally different
origins.
I've never seen any that could flash it on or off faster than *praecox*,
but pupfish from the American desert and gulf coast do a similar thing.
In *Cyprinodon nevadensis* and *variegatus*, the shiny area is a double
line from the front end of the dorsal to near each eye, making a
shallow, inverted "V." They flash it at the girls to attract them to the
breeding site. The color is a bright blue-white.
I have some new *Bedotia gaeyi* (Madagascar Rainbows) in a long
"tea-colored" tank. The other night, I thought they were lighting up
little blue sparkling portholes along the lateral line, just above the
dark stripe. Was I seeing things? Was it an artifact of the lighting?
I'm curious if this is actually common and everyone but we newbies have
seen it.
Wright
-- Wright Huntley, Fremont CA, USA, 510 494-8679 huntley1 at home dot com