Phylum Porifera

Phylum Porifera is an exclusive classification of aquatic animals. It belongs to the Animalia kingdom with a sponge-like structure. As it is a multicellular organism, the cells are arranged either randomly symmetrical or asymmetrical. They are simply called with the name of sponges. We can find around 5000 species so far with different shapes and colours. Each species has a distinct feature.


Porifera, a Latin word that means bearing pores.Because if it's a sponge-like structure, it can absorb and hold the water for a long time.


Structure

These species have a bundle of little needle-like structures called Spicules. And some of the big pores called Ostia which helps to draw into the interior canal called spongocoel. This water is filtered into the radical canal and split out from the organism through exit pores called the osculum. The only purpose of this water is helpful in their reproductive system; for the formation of eggs or for sending sperms.


Origin and Life cycle

In the beginning, the sponges are treated as plants due to their immobility. They look like algae in the sea bed. Later observations like preparing its own food, absence of chlorophyll, reproductive system, long life, etc. were confirmed that they belong to the animal kingdom.


They are found in shallow and deep seawater and in the beds of freshwater also. Besides, these features, sponges have the classification of four classes.


Classification of Porifera

Based on the Spicules which are made up of calcium carbonate, sponges can be classified into three classes. They are-


Calcarea:- These sponges are found in marine forms of living shallow water in small size. Calcarea Spicules form a skeleton that results in the cylindrical shape of the body for which the animal is symmetrical. Coeloblastula or amphiblastula helps in the development and the body may be organized like the asconoid or conoid type. In this, large cells are known as Choanocytes. Again these Choanocytes are sub-classified into two orders based on the structures. They are - Homocoela and Heterocoela.


Hexactinellida:- Large sponges are present in this. As the name itself says that it has six-rayed glossy Spicules which can help to grow long from 10 to 30 cms. They are mostly found in deep layers of the sea. They have finger-like canals and possess some inorganic elements. Its shape seems to be like a cup or vase. Euplectella, Hyalonema are some of the examples.


Demospongiae:- These sponges may be found from shallow to the depth of the sea in different colors with the presence of pigment granules. Mostly available species are of this category. The skeleton may or may not be present, and the body will be either in round shape or flattened shape. Oscarella, Plakina, Geodia are some of the examples.


Based on their unique feeding system, also, different classes have been classified, such as - carnivorous and many more. Also, we have subclasses in these categories which can be learned in the next grade.


Now we will see the characteristics of the Porifera in a detailed view.


Characteristics of Porifera

Different Characteristics of Porifera are Explained as Follows -

  • They are the sponge-like structure that can be helpful for the circulation of water.

  • These are marine aquatic organisms that can be found in shallow and deep freshwaters.

  • They grow and seem to be like plants.

  • They are available in a cylindrical, round, cup, vase-like shape based on the presence of pores.

  • Pores are arranged in symmetrical as well as asymmetrical which can hold and circulate water for a long time.

  • The entire development will be done inside only.

  • The reproductive system is done by both the ways called sexual and asexual like budding and fragmentation.

  • Sponges can prepare their own food as well as eat other organisms as well.

  • Its nutrition is holozoic.

  • It is a multicellular organism, but excretory and respiratory systems were absent.

  • The diffusion process also takes place in it.

  • It can regenerate its power automatically.


Reproduction

It plays a vital role in sponges. Because with this system only our scientists transformed this to animal kingdom from plant life. It can reproduce in both ways called sexual and asexual. Again in asexual, it undertakes the budding process as well as the fragmentation process. The sexual process is a combination of ova and sperm, just like common to all other species.

FAQ (Frequently Asked Questions)

1. What is Porifera?

Ans. Porifera is a multicellular organism that belongs to the animal kingdom, which doesn't have tissues and organs.

2. Write Some Examples of Porifera?

Ans. Sycon, Leucosolenia, Oly thus, Cla thing, Hya lone, Spongilla etc. are some of the examples.

3. Where do you Find These Porifera?

Ans. As these sponges are aquatic organisms, most of the species are found in Marines, some are at freshwater.some other at depth of seas.

4.Where does the Word Porifera Derived?

Ans. The word 'Porifera' was derived from the Latin which means 'bearing pores'. It was coined by Grunt.

5. How many Classes of Porifera do we Have?

Ans. We have many thousands of sponges there. These are classified into three groups based on different aspects. They are - Calcarea, Hexactinellida, Demospongiae.

6. What do Porifera Eat?

Ans. Some of the species of Porifera will eat small, tiny, floating organisms on sea level and some other species collect food from the filtered water.