Phyllum Coelenterata – Cnidaria

Glass Sponges

Demosponges

Calcarea or Calcareous Sponges

Phyllum Porifera – Sponges

This phyllum consists of simple muticellular animals that are mostly found in aquatic habitats. Their unique characteristic is that their cells are held together so loosely that they do not form tissues. Most porifera have pores known as ostia found all over the body and have a large opening on the tops, called an osculum. They have a canal that supports the intake of food and oxygen, and have a support system made up of tiny needle like formations of silica, spongin fibres and calcium. Amazingly, the reproduction in this segment of the animal kingdom may be sexual, asexual or even budding. Some examples of porifera are sycon, spongilla and euptectella.

1. Old name - Coelenterata
2. Majority marine, but a few freshwater species.
3. Metazoan, with tissues, triploblastic, acoelomate.
4. Phylum exhibits polymorphism. The two main structural types are the polyp and the medusa.
5. May be solitary or colonial.
6. Typical larval form is planula.
7. Exhibit some form of radial symmetry.
8. Generally possess a ring of tentacles around the oral end.
9. The single body cavity is the coelenteron.
10. The body wall is three-layered.
11. Possess nematocysts, special cell organelles used for offense and defense, located in cnidoblast cells of epidermis and gastrodermis
12. Possess undifferentiated interstitial cells (mesoglea), which gave rise to sex cells and cnidoblasts, and are also involved in regenerative and reproductive processes
13. Nervous system a network and not centralized (nerve net)

1. Class Hydrozoa

1. Class Scypohozoa (Jelly fish)

1. Class Anthozoa

Дата добавления: 2014-12-23