Porifera, also known as sponges, are simple aquatic animals with porous bodies and no true tissues. They feed through pores and have cells that perform specialized functions. There are over 8,000 known species of marine and freshwater sponges that vary greatly in size, shape, and skeleton composition. Sponges are classified into three main classes: Calcarea, Hexactinellida, and Demospongiae. Cnidaria are aquatic animals that have stinging cells called nematocysts. They have radial symmetry and go through medusa and polyp life stages. The four main classes of Cnidaria are Hydrozoa, Cubozoa, Scyphozoa, and Anth

1. PORIFERA
General characteristics:
-They feed through pores on their outer walls.
-Cells are not organised to tissues or organs.
- Different cells perform different functions.
-They are both asexual and sexual.
-Their skeleton is made up of collagen and
spicules.
-Porifera are also known as Sponges
-There are more than 8,000 known species of
Porifera in the world.

2.  Classification of porifera:
There are about 5,000 species of sponge, mostly marine and few freshwater
species. In sea they occur up to a depth of 8,500 m and mostly flourish in warm
waters. Size can vary from a few cm to several metres. The body shape is highly
variable.
Class CALCAREA
(=CALCISPONGIAE) Class HEXACTINELLIDA Class DEMOSPONGIAE.
Small marine (=HYALOSPONGIAE). M Massive frame sponges
sponges with arine glass sponges with with sponging fibres and
calcareous spicules. 6-rays spicules. siliceous spicules.

3. CNIDARIA
 General characteristics:
- All Cnidaria are armed with stinging cells called nematocysts.
- There are four major groups of Cnidaria: Anthozoa, Cubozoa, Hydrozoa, and
Scyphozoa.
-They have radial symmetry.
- At some point in their lives they develop a medusa and a polyp stage.
-Medusa- a free-swimming bell, shaped stage, with tentacles extending below the bell.
-Polyp- Vase shaped, sedentary stage of Cnidarian life cycle.
-They have a gastrovascular cavity that serves as a mouth for eating prey and as an anus.
-They are free-swimming and floating at different stages in their life.

4.  Classification of cnidaria:
Class Hydrozoa: Hydrozoas. Hydra, Obelia,
Gonionemus, Physalia
Class Cubozoa:Sea wasps. Tripedalia
Class Scyphozoa:Jellyfish. Aurelia, Pelagia,
Cyanea
Class Anthozoa: Sea anemones and corals.
Metridium, Pennatula, Gorgonia, Astrangia

5. By:
Lizaveta Ramanouskaya
Cristina Gómez Herrero

6. By:
Lizaveta Ramanouskaya
Cristina Gómez Herrero