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.
Cnidarians are classified into four main groups: non-moving (sessile) Anthozoa (sea anemones, corals, sea pens); Cubozoa (box jellies);swimming Scyphozoa (jellyfish); and Hydrozoa, a broad group that includes all the freshwater cnidarians as well as many marine forms.There are about 10, 000 species of Cnidarians.nidaria is a phylum containing over 9,000 species found only in aquatic and mostly marine environments. All cnidarians have radial symmetrical. There are two major body forms among the Cnidaria-the polyp and the medusa. Sea anemones and corals have the polyp form, while jellyfish are typical medusae.