Abstract
The present study attempted to provide information on the abundance and distribution of dusky spine foot, Siganus luridus (Rüppell, 1829), with respect to the food and feeding habits of this species along the Gulf of Aqaba, Red Sea, Egypt. A total of 649 fish specimens were monthly collected from different localities in the Gulf of Aqaba during the period from January to December 2018. After collection, the stomach contents were examined to determine the feeding activity and food items. The abundance and size structure of target species were recorded and estimated using underwater visual census (UVC). Results showed that the fish are moderate actively fed. The annual average of feeding activity constitutes 63.09% of the total stomachs examined. The lowest value of feeding activity was recorded during winter (45.07%), while its highest was during autumn (88.28%). The rabbitfish, Siganus luridus is essentially herbivorous consuming a wide range of plant food. Algae (99.73%) were by far the most dominant and preferred food item consumed by the fish, mainly brown algae (87.73%), followed by the turf algae (8.31%) and the red algae (3.69%). Seagrass is sporadically consumed (0.04%) and rubble (0.23%) was found in the stomachs with minor percentages. The highest abundance of S. luridus in the algal habitat was recorded during July, August, September, October, and November, while the lowest occurred during December, January and February. On the other hand, the highest abundance of S. luridus in coral reef habitats was recorded during spring and summer. In conclusion, the highest abundance of S. luridus depends on the algal habitat; in autumn by the end of the spawning season, the highest feeding activity was observed. On the other hand, the highest abundance of fish in the coral reef habitat was recorded during spring and summer in the spawning period of the fish since they use the coral reef as a nursery ground. Besides, opening up the space on the substratum by grazing the algae is necessary to facilitate the colonization of corals.