Branchiobaetis megasinus sp. nov. a accessory gills (vertical arrows) between coxa and prosternum on foreleg and bubble-like membranous swellings (horizontal arrows) b foreleg of final instar larva c claw d foreleg femur e foreleg tibia f foreleg tarsus. Scale bars: 0.5 mm (b); 0.1 mm (d, e, f).