Hello Robert -
I have used MIX software from Ichthus Data Systems in Canada to fit
fish length frequency data to Von Bertallanfy growth curves. This
program is available for IBM's and clones (and I believe UNIX boxes) as
well as Macintosh (which I use). I'm not sure if anyone has ever used
it for turtle data. The authors (Peter McDonald is one that I remember
off hand) offer to help people use the program, for free.
Since I am at home now, I don't have the complete reference and address
available. I could get it to you on the 7th of Jan. when I return to
work if you still need it.
Marine Resources Division
P.R. DNER, San Juan, Puerto Rico