Azoospermia is the medical condition of a man whose semen contains no sperm. It is associated with infertility, but many forms are amenable to medical treatment. In humans, azoospermia affects about 1% of the male population and may be seen in up to 20% of male infertility situations. 1 Classification 1.1 Pretesticular.
Nematocysts are the stinging cells on tentacles of a cnidarian, like a jellyfish. Since jellyfish don't have any teeth, and their body consists of gelatin, it's hard to captur â¦ e prey.Nematocysts help jellyfish with feeding by stinging the prey in an attempt at trying to immobilizing the prey.hat is a Cnidarian? cnidarians, such as jelly fish, sea anemones, hydra, and corals, have tentacles surrounding their mouth. they are a hollow-bodied animal with two celled layers that are organ â¦ ized into tissues. the inner layer forms a digestive cavity where food is broken down.
Cnidaria: Life History and Ecology. Cnidarian ecology is a complex subject indeed, because it is cnidarians, in particular corals, that are the builders of some of the richest and most complex ecosystems on the planet, coral reefs.Other cnidarians are important as predators in the open ocean. Cnidarians generally occupy two major niches.They may use their cnidocysts to trap prey items. On the other hand, many cnidarians, anthozoans in particular, depend on zooxanthellae, symbiotic dinoflagellates within the tissues, to survive.ther cnidarians are important as predators in the open ocean. Cnidarians generally occupy two major niches. They may use their cnidocysts to trap prey items. On the other hand, many cnidarians, anthozoans in particular, depend on zooxanthellae, symbiotic dinoflagellates within the tissues, to survive.