Evaluation of red seaweed Gracilaria arcuata as dietary ingredient in African catfish, Clarias gariepinus.
Shamlol, Nasser A. Al-Asgah a, El-Sayed M. Younis a,*, Abdel-Wahab A. Abdel-Warith a,b, Faozi S. . 2016
The aimof this study was to evaluate the use of driedmarine seaweed, Gracilaria arcuata for
the first time as dietary ingredient in partial substitution of fishmeal on the growth performance, feed
utilization and body composition of African catfish, Clarias gariepinus. Four experimental diets were
formulated:D1 as a control group;D2; D3 andD4which included 10%, 20%and 30%G. arcuata meal
respectively.One hundred and eighty African catfishweighing 9.62±0.42 g, (mean±SE)was divided
into four groups corresponding to the different feeding regimes. The final body weight of the fishes
showed significant differences (P<0.05) between the control (D1); D2 and other treated groups D3
and D4, with weights of 66.98, 59.60, 47.34 and 30.73 g recorded for D1, D2, D3 and D4, respectively.
Significant differences (P<0.05) were also evident inweight gain, specific growth rate, and feed utilization
between treatment and control groups. However, no significant differences (P>0.05) were
observed between the control group and fishes fed D2 for all previous parameters. Protein productive
value, protein efficiency ratio, daily dry feed intake and total feed intake were also significantly lower
in fish fed with a diet containing G. arcuata than in the control group and D2 which contains 10% of
G. arcuata. Overall, the results of the experiment revealed that African catfish fed a diet with G. arcuata
included in 20%and 30%levels showed poorer growth and feed utilization than the control group and
D2. However, the study recommended that C. gariepinus can accept this ingredient up to 10%in their
diets.More defined experiments therefore seem to be necessary in order to determine the maximumlevel
of this marine seaweed in diets with amino acid supplementation for African catfish.
