- Asexual by budding, fragmentation

- Sexual by hermaphroditic release of sperm and ova into the water

Cnidaria (Jellyfish, corals, sea anemones, hydras)

- Asexual by budding, fragmentation, strobilation (in some jellyfish)

- Sexual by the production and release of sperm and ova into the water to fertilize externally

Platyhelminthes (Flatworms)

- Asexual by fission, fragmentation

- Sexual by hermaphroditic internal fertilization and cross-fertilization between two individuals

Nematoda (Roundworms)

- Sexual by internal fertilization with specialised male and female organs

Annelida (Segmented worms)

- Asexual by fragmentation

- Sexual by both cross-fertilization between individuals and self-fertilization, depending on the species

Mollusca (Clams, snails, octopus)

- Sexual by internal fertilization, with specialised male and female organs

Arthropoda (Insects, spiders, crustaceans, centipedes and millipedes)

- Sexual by internal fertilization, with specialised male and female organs

Echinodermata (Sea urchins, sea stars, sea cucumbers)

- Asexual by fission, fragmentation, or autotomy (self-amputation)

- Sexual by external fertilization, releasing sperm and ova into the water.

Chordata (Fish, amphibians, reptiles, birds, and mammals)

- Sexual by internal fertilization, with specialised male and female organs