  The properties of biological microswimmers are to a large extent determined
by fluid-mediated interactions, which govern their propulsion, perception of
their surrounding, and the steering of their motion for feeding or in pursuit.
Transferring similar functionalities to synthetic microswimmers poses major
challenges, and the design of favorable steering and pursuit strategies is
fundamental in such an endeavor. Here, we apply a squirmer model to investigate
the pursuit of pursuer-target pairs with an implicit sensing mechanism and
limited hydrodynamic steering abilities of the pursuer. Two hydrodynamic
steering strategies are applied for the pursuer's propulsion direction by
adaptation of its surface flow field, (i) reorientation toward the target with
limited maneuverability, and (ii) alignment with the target's propulsion
direction combined with speed adaptation. Depending on the nature of the
microswimmer propulsion (puller, pusher) and the velocity-adaptation scheme,
stable cooperatively moving states can be achieved, characterized by specific
squirmer arrangements and controllable trajectories. Importantly, pursuer and
target mutually affect their motion and trajectories.
