Distribution and feeding habits of two surgeonfish, Zebrasoma xanthurum and Ctenochaetus striatus in the Gulf of Aqaba, Red Sea

Abstract EN

The distribution and feeding habits of Zebrasoma xanthurum (Blyth, 1852) and Ctenochaetus striatus(Quoy and Gaimard, 1824) have been studied fora period of 13 months on the coral reefs at Naama Bay, Gulf of Aqaba, Red Sea.

Z.

xanthurum was a grazer whereas C.

striatuswas a detritus feeder.

Dentition and alimentary tracts reflected on the food habits of.

each species.

The feeding rate in Z.

xanthurum was higher than in C.

striatus; however, both species exhibited definite daily patterns.

Feeding was very lowin the morning, peaks in late afternoon and drops sharply as night approaches.

The amount of food in the stomach was very low, however, the food weight in the whole gut reaches up to 30 % offish body weight daily.

In Z.

xanthurum, brown algae were the main food items (44.4 %), followed by red algae (26.4 %), blue green algae (18.2 %), green algae (4.7 %) and diatoms (2.4 %).

Animal food contributed only 2.1 % of the diet.

In C.

striatus, substrates (sand and fragments of dead corals) were the most abundant (58.6 %) component in the stomach, followed by diatoms (8.6 %), red algae (7.6 %), brown algae (6.7 %) and blue-green algae (5.6 %).

AnimaIfoods constituted 10.3 % of diet and included foraminifera (3.6 %), sponges (2 %), coelentrates (1.4 %) and fish eggs (1.6 %).

The different food items in both species exhibited seasonal fluctuations in relative abundance.