Asexual (hydra)
Hydrozoa reproduces asexually by budding. The cavity of bud is continuous with that of the parent. The bud pinches off and drops to leave a separate existence.
Sexual (hydra)
The testes and ovaries are formed in the body wall. There are many sperm released into the water. The eggs are fertilized in the ovaries. The embryo breaks loose from the parent and matures as young hydra.
Some species of hydra are hermaphroditic. i.e. One individual produces both egg and sperm.
ObeliaMedusas are produced as buds and they reproduce sexually. The fertilization takes place externally.
Scyphozoa
Asexual
Medusas are produced by budding from polyp stage.
Sexual
There are separate sexes. The fertilization occurs in the water. The zygote develops into ciliated larva which attaches to rocks and develops into polyp form.
Anthrozoa
Asexual
Many of the species reproduce by budding.
Sexual
There are separate sexes. The gonads are kept in the gastrovascular cavity. the zygote develops into ciliated larva which attaches to rocks and develops into polyp form.
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