RE: [Killietalk] arnoldi story

["Tranquility Base" <TranquilityBase at netzero_net>]

Hi Folks:

Let me tell you guys a little story.

When I was in college my Biology T/A was working on his doctoral
dissertation. He was trying to prove that poison Ivy was a distant relative
to the Spanish Cork Tree. If he succeeded, he would achieve his doctorate
degree and get to demand a higher pay check.

But in fact I am pretty sure that few wineries are likely to start sealing
their finest vintages with poison Ivy vines.

My point?

With all of the real needs this world has like pollution, over population,
curing AIDS diabetes and cancer, there will always be some uninspired
talentless PhD candidates that have little better to do than reclassify
something that relatively few people really care about. As killies make for
cool photos to attach to scientific papers, now published in color, I think
that they and we are unfairly targeted.

One scientist divides the species while the next groups them back together.
As I recall Occidentalis and Todi were once 'Large Rolofia' Then they were
lumped together with the Aphys, subdivided off with the Fundulopanchax and
finally split off into the Callopanchax group. I'm not entirely too sure,
but the new Callopanchax group looks suspiciously like the Large Rolofia
group we started off with in the first place.  (Sorry about the spelling
folks. I'm too rushed to look it up tonight.)

I suppose that there is nothing wrong with a system that produces more
highly paid PhDs than ever before, but for me, I don't get too concerned
when someone reclassifies a fish, sooner or later someone else will
reclassify it into something I like better.

Peace,

~RJ~



-----Original Message-----
From: killietalk-bounces at aka_org [mailto:killietalk-bounces at aka_org]On
Behalf Of Wright Huntley
Sent: Monday, January 05, 2004 5:58 PM
To: killifish discussion list
Subject: Re: [Killietalk] arnoldi story




Chris wrote:

> Wright,
>
> How does one differentiate between two closely related species.

Back when I got into the hobby (early '50s), it was really easy. If they
produced fertile offspring they were the same species. If they didn't,
they were not. Then the water started getting muddy... :-)

> I don't
> believe that there is any magic number of restriction fragment length
> polymorphisms (RFLPs) that determines species.  If there were it would
> take all the fun out of taxonomy.  Different species have different
> numbers of   RFLPs between them depending on how broad the gene pool of
> that species is.

Agreed.

> Some species, like ours (H. sapiens sapiens), have a very small gene
> pool and all members are very closely related. Where as other species
> have much broader gene pools and individuals are not as genetically
> similar.

This tends to be particularly true when the reproductive isolation is
fairly recent, but wasn't always constant, historically. Look at Desert
Pupfish for a good example. Floods and varying water levels allowed all
kinds of genetic combinations at times. At other times they have gone
centuries in complete isolation.

>
> I know you are a dog person so lets use this for instance, according to
> Coppinger, et al, it is not possible to differentiate between Dog, wolf,
> Coyote, and Jackal DNA.  The line between species is too vague.  They
> share too many genes and the distribution of genes is somewhat random
> among the whole group.

This is where species definition frequently becomes more a matter of law
and full-employment-for-game-wardens policy than a matter of science. :-)

Collector ego trips also make defining new species highly desirable. It
gets even worse when Brazil gives a cash award for each new species
defined. I'm not impressed when the difference between species depends
on the relative length of the 7th and 8th anal fin rays. :^) Many SA
Annuals are getting close to being that absurd.

>
> I'm far from an expert on this so please correct me if I'm mistaken.
> Actually I'm not disagreeing with your hypothesis I just don't think we
> are at the point where we can say this male is not the same species as
> this female when those species are very closely related.

As an expert in molecular biology and taxonomy, I'm a pretty good
electrical engineer. ;-)

I believe (without proof) that closely-related species, like FIL and ARN
tend to select mates of their own species when in the wild, but can
create somewhat fertile offspring if they are forced into the company of
a mate of the other species after collection. When that happens,
fertility may never be good, and probably drops with each new generation.

FIL and ARN females are distinguished by the points on the ARN caudal
and the rounded caudal of the FIL female. Otherwise, they might be
pretty hard to tell apart. Question is, are they kept strictly apart at
the holding site of the commercial collector? Is the collector
unscrupulous enough to send females from one site and males from another
to reduce breeder competition? Are we sharp enough to catch such subtleties?

I'm particularly suspicious of the *Paludopanchax* sub-species as they
all have shown real breeding problems after a generation or two in
captivity, and they are collected practically within walking distance of
each other, usually commercially shipped out of Lagos, Nigeria. That
part of the world is better known for bigger scams (I am getting
$25,000,000 just for letting them use my bank account), but honesty and
honorable behaviour isn't given much value in that region.

I really don't know enough genetics to know if a DNA test could be
devised to clearly distinguish these closely related (and, in the case
of *arnoldi*, highly variable) species. I don't think we will get
long-term survival in the hobby without such a test or a whole lot of luck.

I'll be interested in seeing how the KCC *arnoldi* initiative works out.
In fact, I'd like to be a part of it, if more breeders are needed.

Wright

--
Wright Huntley -- 760 872-3995 -- Rt. 001 Box K36, Bishop CA 93514

     "...there are only a limited number of things that government
  can do more effectively than individuals or other organizations
  can do."
      -- T. Sowell


To join the AKA see http://www.aka.org/pages/join.html
Archives are at http://fins.actwin.com/killietalk/


To join the AKA see http://www.aka.org/pages/join.html
Archives are at http://fins.actwin.com/killietalk/