Feeding ecology of the angelfish species Pomacanthus asfur and Pomacanthus maculosus.

The feeding ecology of the angelfish species Pomacanthus maculosus and Pomacanthus as fur was studied at the coral reefs of Massawa in Eritrea, a country situated at the westcoast of the Red Sea. These angelfishes are active during the day and feed mainly by nipping the substrate within a small home range. The feeding activity in terms of bite rate was investigated during different parts of the day for both species, but the intraspecific variation was to high to draw conclusions about variation in feeding activity during the day. Looking at the entire day, P.asfur has a higher bite rate than P.maculosus. Stomach contents were analysed in order to determine diet and interspecific overlap. Sponges and algae made up the largest part of their diverse diets, so both species can be regarded omnivorous. The stomach contents of P.maculosus were clotted in packages, those of P.as fur consisted of pulvensed material. The digestive tracts of these angelfishes are structurally similar. Their fairly strong stomach, long intestine and terminal sac makes them well adapted to their omnivorous way of feeding. P.as fur has a relatively longer intestine than P.maculosus and together with the fact that its stomach content is already more pulverised, it seems to have a higher capacity for nutrient absorption than P.macu!osus.