Notes on two shallow water isopods (Crustacea: Peracarida: Isopoda: Idoteidae) from Kino Bay, Gulf of California, Mexico

Two species of isopods of the family Idoteidae were collected in the same sample, among sea grasses, in the northern Gulf of California, Mexico. The first species, Synidotea harfordi Benedict, 1897, was more abundant (46 specimens) than the second species, Eusymmerus antennatus Richardson, 1899 (eight specimens). Synidotea harfordi has previously been considered uncommon in the Gulf of California, and more like a component of warm-temperate to colder-water fauna. The male of E. antennatus has not been illustrated but SEM photographs are provided and show angular margins of the first three pereonites and a sharply bent lateral margin of the telson. Females also have angular first pereonites. All previous illustrations show rounded pereonites margins. Buccal appendages of E. antennatus are illustrated and compared with previous descriptions.