Feeding competition between two goby species, Pomatoschistus lozanoi (de Buen) and P-minutus (Pallas) in a macrotidal saltmarsh

Two transient goby species (Pomatoschistus minutus and P. lozanoi) occurred in saltmarshes of the macrotidal Mont-Saint-Michel bay. They colonised the tidal creeks during each spring tide throughout the study conducted in 199 7. P. minutus swallowed a least 4 % of its body weight, its diet was domina ted by the most abundant resident amphipod of the saltmarshes, Orchestia ga mmarellus. P. lozanoi ingested less food during their stay in the creek (2. 4 % of its body weight). O. gammarallus also occurred in its diet, but mysi ds were the main food items both during flood and ebb. In addition to this trophic segregation, a temporal segregation was observed. In fact, Fl minut us stayed longer than P. lozanoi in the saltmarsh; it colonised creeks firs t and returned to coastal waters the last. These two predatory and sympatri c species have a different trophic behaviour that limits interspecific comp etition both from the trophic and temporal point of view. O 1999 Academie d es sciences / Editions scientifiques et medicales Elsevier SAS.