How can you tell male and female lobsters apart?
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The differences between male and female lobsters can only be seen when they are turned on their backs. In the male lobster the two swimmerets (forked appendages used for swimming) nearest the carapace (the solid shell) are hard, sharp, and bony; in the female the same swimmerets are soft and feathery. The female also has a receptacle that appears as a shield wedged between the third pair of walking legs. During mating the male deposits sperm into this receptacle, where it remains for as long as several months until the female uses it to fertilize her eggs as they are laid.