Estuary;"Putative Sibling Species Pair";Reference;"Mean % COI genetic distance";N;"Brackish / estuarine (oligohaline)";"Marin e/ Estuarine (euryhaline)" "Canadian estuaries";"Gammarus tigrinus Sexton, 1939";"Gammarus lawrencianus Bousfield, 1956";"Steele and Steele (1991)";24.86;172/70 "North American estuaries";"Gammarus daiberi Bousfield, 1969";"Gammarus tigrinus Sexton, 1939";"Bousfield (1973)";14.54;4/172 "Deltaic Area, Holland";"Gammarus zaddachi Sexton,1912";"Gammarus salinus Spooner,1947";"Den Hartog (1964)";14.62;60/82 "Deltaic Area, Holland";"Gammarus salinus Spooner,1947";"Gammarus locusta (Linnaeus,1758)";"Den Hartog (1964)";26.35;82/94 "Deltaic Area, Holland";"Echinogammarus marinus (Leach, 1815)";"Echinogammarus obtusatus (Dahl, 1938)";"Den Hartog (1964)";33.29;36/31