Channel catfish (Ictalurus punctatus, Rafinesque, 1818) is one of the most important species for aquaculture in Mexico.
Pangasius hypopthalmus , known as Basa, is not officially recognized, but a lready cultured in different states. Weight Length relationship (WLR)
is
an useful that can be used for converting lengths into biomass, determining the fish condition, comparing fish growth among areas, and complement to species-specific reproduction and feeding studies.
An experiment was conducted submmiting fishes to growth-out conditions during 40 days using 1 m3 floating cages (three repetitions by population) at a density of 250 fishes/m3. Using f inal weights and furcal lengths, double logarithmic regression models were fitted to estimate a and b parameters. Fulton condition factor (K) was estimated.
The Figure 1, shows the logarithmic plots of data from Local Channel Catfish and Basa . The line of prediction estimated a b =3.02 (R2 >0.95) indicating isometric growth. Basa population WLR had a slightly lower b parameter (b= 2.92, R2 >0.95) that suggest a relative negative allometric of hipo-allometric, and can be interpreted as fishes that weigh less than their length predicts or, related to the better feeding condition of small organisms at the time of sampling. K for Channel Catfish and Basa catfish populations, were 1.84±0.127 and 1.65±0.179, respectively, with no statistical differences between populations (P>0.05).
The results indicates good and similar growth potential under commercial conditions and estimates can be used as reference information or prediction of biomass under commercial conditions .