How do they find their mates?

How do males recognize females? Given that males and females look very similar from the vantage point of another horseshoe crab, how can they sucessfuly distinguish between the two sexes so that females with a male in tow?

The following 3 sets of experiments on horseshoe crabs demonstrate how different properties of their visual systems may be used in successfully migrating and finding mates.

Each of these three lines of investigation involves behavioral studies, electro-physiological studies, and observational techniques. Since research from one set of studies often builds on what has been learned in another, it is suggested that the viewer follow the investigations in order (part 1, then part 2, then part 3).

Part 1. Mate finding

Part 2. Shape discrimination

Part 3. Beach finding