Observations on food and feeding habits of the common smooth hound shark, Mustelus mustelus in the Mediterranean Sea at Alexandria coast, Egypt

The present study aimed to provide information on the food and feeding of the common smoothhound shark, Mustelus mustelus in Egyptian Mediterranean waters at Alexandria, Egypt. A total of 306 specimens of M. mustellus were monthly collected from the commercial catch at Alexandria coast of the Mediterranean Sea, from June 2020 to May 2021. Results revealed that the annual average feeding activity of the whole population of M. mustelus constitutes 65.40% of the total examined stomachs. According to season, the highest recorded feeding activity was noted during summer (73.86%) and spring (71.01%), and the lowest value (55.56%) occurred during winter. According to life stages, the annual average value of heavy, good, and medium stomachs constitutes 64.77%, 71.57% and 60.92% of the total examined stomachs in juveniles, sub-adult and adult fish, respectively. Results showed that M. mustelus is essentially a predator shark, consuming a wide range of aquatic food. The major recorded animal foods are crustaceans and fish. The other minor items included Mollusca and Nemertea. In the whole population of M. mustelus, crustaceans were the most preferred food items (52.58%) followed by fishes (33.53%); they displayed seasonal fluctuation in fish’s diet. The diet of the fish showed considerable variations in different-sized groups and during consecutive seasons within the same-sized group. This study concluded that Mustelus mustelus in the Egyptian Mediterranean waters at Alexandria is considered a moderately feeder active fish, with considerable differentiation in their diet during different life stages, and seasons.