[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Heterandria formosa - is it a Killi?



> H. formosa is as much a killifish as a lamp-eye and it is not in the same
genus as the guppy but the same family, as well as the suborder Poeciliidae.

What a teaser you are Tyrone!

> See
> http://www.calacademy.org/research/ichthyology/catalog/classif.html
Hey Tyrone!

Thank you both for the for the comforting words below and the great source.
I really could have used it a couple of weeks ago when spending hours
looking up something on Rainbows for a little club event.

Good thing after all those hours (which could have been spent pursuing
something one gets paid for) that the sites were free. (Then after muddling
through the on-line stuff, the new Rainbow book arrived from Germany the day
after and then Peter Unmack posted his research).

Your observation that none of the taxonomy games have changed the essential
nature of our killies is a source of solace for those of us who can't tell
one head bone from another nor really want to.

> Feeling confused?
> Irrelevant. Changing the relationships have not changed the fish. A
> lamp-eye is as much as killi to me today as it was last year.

Chip's nomination of Pygmy Livebearer for the "Hets" is a terrific idea.
(It's good to have a resource person and story teller of his stature on this
list too.)

Aren't the formosa the smallest vertebrate in North America? I think they
are all the way up to about the 6th smallest vertebrate world-wide now.
(They keep finding these little gobies in the Philippines.)

> Are livebearers killifish? Of course not! They have their own society.:-)

And yet, as if the taxonomists didn't confound us ordinary bums enough with
classification clarifications and revisions, now it seems that the
livebearering toothed carps and egg laying toothed carps have a history in
many ways intertwined.

John Dawes (in Livebearing Fishes: A Guide to Their Aquarium Care, Biology
and Classification 1991 & 1995) draws upon the work and conclusions of Lynne
Parenti and Mary Rauchenberger and a John Wourms 1981 study to really raise
some mind boggling thoughts for those (like me) who like everything sorted
out in neat little non-threatening categories. One of Parenti's contentions
is that livebearing is something that has evolved in several different
situations and should not be a criterion for graphing relationships or
drawing cardiograms.

So there is Poeciliid Tomeurus gracilis (something of a half way creature
between what we think of as our traditional killies and out traditional
livebearers) which internally fertilizes females who then lay eggs.

And now "our" Crenichthys and Empetrichthys are placed in the family with
the livebearing Goodieds! "Our" Oxyzygonectes (the white eyes) are placed
close to the livebearing Anableps (the four eyes).

Could it be that the Poeciliids and the Goodieds sprang from "our
killifish"?

To muddy the water further, Dawes notes that there are cases where another
honorary killie, the Japanese ricefish Oryzias latipes (the Medaka) seems to
have had females spawn with males only to eject fertile eggs some time
later.

Getting closer to "home", Rivulins such as Cynopoecilus melanotaenia and
Campellolebias brucei have modified anal fins which indicate that their
females in some situations could have their eggs fertilized within their
bodies.

Dawes even pulls out the case of a tetra which seems to practice internal
fertilization! (Never mind all those sharks and surf perches.)

Now for lots of us this of no consequence, for others of interest in such a
way as to make the hobby a little more interesting, and for some, for whom
relationships are terrifically important, it must be very significant.

For the purposes of this posting, let the complex relationships our killies
have with one another and with a bunch of livebearers allow us to raise
whatever we want in good conscience. Sometimes we get too elitist in our
aquatic specialties. (Specialization is fine but not at the price of putting
down others.)

Interesting that the West Coast weekend has both killie and livebearer
strands. Sue Bunte mentioned something similar yesterday with the
announcement of the Sacramento show.

I'll bet many of us who just keep killies once cut their aquatic teeth on
one of the commercial livebearers. Several confirmed killinuts also will
admit to having that tank of Het. formosa.

Let's hear it for the honorary killies!. Now if only these little Ellasoma
zonatum continue to grow well. :)

All the best!

Scott


---------------
See http://www.aka.org/AKA/subkillietalk.html to unsubscribe
Join the AKA at http://www.aka.org/AKA/Applic.htm