Invertebrates have many different reproductive strategies. Squids and octopuses reproduce sexually. Other invertebrates use the broadcast method where both male and female gametes are released into the water in enormous quantities and left to unite by chance. Others reproduce asexually. Asexual reproduction results in a genetically identical copy of the parent and is characteristic of cnidarians such as corals and hydroids. and certain worms and sea squirts.
Many invertebrates are hermaphroditic, possessing both male and female sex organs.
Despite this they often lack the capability to self-fertilize and reproduce sexually, with both partners bearing young. Some invertebrate species change sex at different periods in their lives. For example, some shrimp species start life as males and later become females. Brusca, Richard C. and Gary J. Brusca. Gotshall, Daniel W. 1994.