Fish, like this large sting ray, are pulled on board and then removed from the nets. Prior to removing the sting rays, the stinger had to be snapped off. Otherwise, the flailing tail could impale unlucky fishermen. The stinger is a bone and cartilaginous adaptation that is finely serrated on both edges, like a multi-prong harpoon. The stinger is very difficult to remove and it caused more damage trying to pull the stinger out than to push it through to the other side of the wound!
Fish like sting rays and skates are extremely important to provide an oil that is coated on the boat hulls. This oil is created by village specialists and rendered down from the livers. While many of the local fisherfolk do not eat fish like sharks and stingrays on a regular basis, these fish are often sold to the local hotels in Karachi (where they are sold as scallops! You can take a scallop-shaped punch and punch out pieces of meat from the wings; when they are fried, most people can't tell the difference!).