Figure 2. Hydrothermal vents on the MAR with chemosynthetic bivalves and hydrocarbon seep areas on the western and eastern Atlantic margins with the B. boomerang species complex.

Left: Overview on North Atlantic vents and seeps. Vema and Romanche are large transform faults. Right: Locations of the 5°S and 9°S vent fields on the MAR. 5°S = SMAR vents Golden Valley, Clueless and Wideawake; 9°S = SMAR vent field Lilliput; Bb = Barbados Accretionary Prism; BS = Broken Spur; GoC = Gulf of Congo; GoM = Gulf of Mexico, Lo = Logatchev Hydrothermal Vent Field; LS = Lucky Strike; MG = Menez Gwen; Rb = Rainbow; SP = Snake Pit.