Fig. 10. (A) The shear stresses surrounding a rotating abalone egg. Model output is displayed as a pressure map, with x and y axes oriented parallel or perpendicular to the direction of flow, respectively. Relative to flow, two 45° transects (broken lines) were established upstream and downstream of the modeled egg surface. G (s^–1) is fluid shear generated in the Taylor-Couette flow tank. (B) The relationship between F_swim/F_shear and distance from the modeled egg surface along a downstream (Left) or upstream (Right) transect. Sperm were modeled as prolate spheroids. (C) Distance from the modeled egg surface along a upstream transect where F_swim/F_shear=1, as a function of G. Local shears vary substantially near an egg surface and are incorporated into our models. Three specific conditions were evaluated: an abalone (Ab) egg (with or without rotation) and a brine shrimp (BS) egg (with rotation).