Alpheus lobidens De Haan, 1849 is a pantropical Indo-West Pacific shrimp species, which invaded into the Mediterranean Sea as Lessepsian migrant. The shrimps (a total of 872 specimens 11-59 mm long) were collected in the Oman Sea during the low tide. The stomachs of 861 shrimps contained food, 602 of stomachs were full. Shrimps feed mainly on detritus (28.1-54.9%), fungi (23.7-47.3%), plants (1.9-20.0%), and dead crustaceans (4.5-11.0% of the stomach content). Eggs of polychaetes were also common in the stomachs. Larger shrimps had lesser share of detritus in the stomachs, while the proportion of plants and polychaete eggs increased. The data show that A. lobidens is an obligatory detritofagous, micromycetofagous and herbivorous species. Dead animals and polychaete eggs may be an additional source of food. Algae, dead crustaceans and cnidarians most likely are available for shrimp only sporadically. A. lobidens may thus be considered as a sanitary species of the littoral zone.