Complex sentence: The female scalloped hammerheads undergo migration offshore at a smaller size than males because the larger classes of the hammerhead, such as those from 100 to 140 cm long, travel deeper down.
Split into simpler sentences: The female scalloped hammerhead undergo migration offshore at a smaller size than males. This is because the larger classes of the hammerhead, such as those from 100 to 140 cm long, travel deeper down.