><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><>
If you reply to this message, it will go to all FISH-SCI members.
><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><>

Dear Listers:
        We were trying to compare growth curves from several populations of 
Argentine silversides from nearby localities (lakes). We have estimates of 
von Bertalanfy's parameteres for all of them and have to compared overall  
growth performance for the stocks. Pauly´s and Delluchi Quinn indices were 
tested for resolution when comparing populations.
        Since we also have estimated survival parameters for those samples 
it came across to us that, by estimating biomass curves for each cohort, a 
population index could come out for consideration. We call it "age of 
population biomass maxima", that is the age at which the cohort reache it´s 
maximum biomass. It seems to us that it integrates overall growth 
performance and survival and improves resolution comparing with those 
indices that consider only growth.  
        Having made severel spacialized refernce searches, suprisingly we 
have not found any relevant ones.
        I would thus appreciate any suggestions or literature citations 
that might help us solve the problem.
        Thank you,

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Eduardo Sendra
Instituto de Limnologia Dr Raul A Ringuelet
CC 712 (1900) La Plata,
Pcia. de Buenos Aires, Argentina
<[log in to unmask]>          

><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><>
       To leave the Fish-Sci list, Send blank message to:
        mailto:[log in to unmask]
 For information send INFO FISH-SCI to [log in to unmask]
><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><>