Spongilla

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What is Spongilla?

It is a genus of sponges found in the freshwater, slow streams and lakes, belonging to the family Spongillidae. Spongilla genus sponges stick themselves to the logs and rocks and filter the water for numerous smaller aquatic organisms including bacteria, protozoans, and other free-floating pond organisms.


Spongilla genus sponges are freshwater sponges and are different from marine sponges as they get exposed to more harsh, diverse, and changing environmental conditions. For this reason, they have gemmules developed in them for dormancy.


Knowing about the gemmules, these are internal buds that are found in sponges and play an important role in asexual reproduction. An adult sponge can develop from these asexually reproduced masses of cells.


The process of the asexual reproduction performed by sponges is budding through external or internal buds (gemmules). Since the gemmules are resistant to drying out or desiccation, lack of oxygen, freezing, and can lie around for a longer time.


When conditions are favourable, the gemmules germinate and form a new sponge. Sponges also have spicules that are present on the dermal layer providing skeletal framework and protection.


Spongilla for the NEET exam is important; let’s discuss it in more detail.


Spongilla is classified under phylum Porifera and these belong to the class Demospongiae.  The common Spongilla species is Spongilla lacustris. Below is a tabular representation of the spongilla classification.


Classification of Spongilla

Kingdom

Animalia

Phylum

Porifera

Class

Demospongiae

Order

Spongillidae

Family

Spongillidae

Genus

Spongilla


Examples of Spongilla

Following are some of the spongilla examples which belong to different species:

  • Spongilla alba

  • Spongilla arctica

  • Spongilla chaohuensis

  • Spongilla cenota

  • Spongilla mucronata

  • Spongilla mucronata

  • Spongilla helvetica

  • Spongilla wagneri

  • Spongilla permixta

  • Spongilla prespensis

  • Spongilla shikaribensis


Structure of Spongilla

Let’s learn some points about the Spongilla structure from the following section:

  1. Spongilla is normally yellowish brown colored, consisting of multiple small individuals having a common flat base.

  2. Spongilla is a common freshwater sponge which is usually colonial and attached to sticks or wood pieces found in lakes and ponds.

  3. Every Spongilla individual is perforated with numerous Ostia and one osculum (which can be one for one individual or one for many individuals).

  4. Spongilla has a rhagon type of canal system and its skeleton comprises spongin fibres having silicious monaxon spicules.

  5. Being delicate in structure, sponges grow as encrusting or branching masses and because of the algae that thrive on them, they appear greenish many times.

  6. Spongilla may attain a volume of over 2.5 K cubic centimetres.


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Characteristics of Spongilla

In this section, we will discuss certain spongilla characteristics that help us to identify and understand their behaviour.

  • Spongilla may be unbranched/branched and consist of numerous Ostia found all over the surface.

  • Their colour ranges from light yellow to green and it depends upon the number of zoochlorellae living on them. Zoochlorella is a green algae having a symbiotic association with it.

  • As discussed earlier, spongilla is found in slow streams, lakes, and freshwater. These get attached to logs, sticks, and submerged plants.

  • Spicules which support its outer surface may be simple, tetraxial, or siliceous.

  • It has a leuconoid type of canal system which is complex and a system of interconnected canals leading to irregular symmetry to Spongilla. 

  • Water enters the Ostia and then to incurrent canals that open into flagellated chambers and these chambers are lined by choanocytes. Further, the flagellated chambers open into the excurrent canal and water here flows outside from the osculum.

  • Extensive division and shrinkage of the spongocoel leads to the formation of excurrent canals.

  • Diffusion is the process of gaseous exchange and excretion in Spongilla.

  • These feed on smaller organic particles and on them, many insects depend for feeding.

  • Spongilla can reproduce asexually or sexually.

  • Budding is the asexual reproduction through budding or gemmules formation.

  • These are hermaphrodite and each sponge can produce egg and sperm. One sponge’s sperm reaches another sponge’s Ostia and development takes place inside the cavity to produce free-swimming larvae.


A Detailed Study about Spongillas

Under the phylum Porifera of Animalia kingdom, a special type of organism called Spongilla is found. It is a genus of different kinds of species resembling sponges that we use in our daily life. This genus comes under the family of spongillidae of order spongilida and class demosponge. These are found in both freshwater  and marine environments having a leuconoid body. Siliceous spicules build the skeleton of the body and that gives the organism a slight rigid structure to hold it together. Leonard Plukenet was the first person to discover such peculiar creatures found in lakes, ponds, streams and in most steady water bodies. These mostly stay in the water bodies by attaching themselves to a base or substrate which can be rocks, floating logs or even on the ground so are famously known as sessile organisms. 


Scientists have discovered the various beneficial services they provide to nature in terms of filtering the water they live in. This is done by the specialised parts available in the spongilla such as ostia and osculum. In turn, this filtered water gets available to the various aquatic organisms and microorganisms thus maintaining the balance of diversity in that ecosystem.


For reproduction, every spongilla produces both sperm and egg in its body so are known as hermaphroditic organisms. Only eggs get released in the water and reach the body cavity of the spongilla through the gateway of ostia. Inside the body, cavity larvae develop after the fertilisation or fusion of egg and sperm.

FAQs on Spongilla

1. What is Chitin in Spongilla?

Chitin is an important structural component present within the skeletal fibres of the freshwater sponge named Spongilla lacustris. After experiments and staining, it has been observed that this sponge’s chitin is much closer to alpha chitin which is known to be present in other animals, rather than to beta chitin. It has also been found that this important structural biopolymer in marine and freshwater sponges was already present in the common ancestor.

2. What are the Important Parts in Spongilla Structure?

The structure of spongilla consists of ocular fringe, spicules, spongocoel, Ostia, bud and substratum. Gemmules are an important part of sponges which are the internal buds and involved in asexual reproduction. It is a mass of cells reproduced asexually and is capable of turning into a new adult sponge.

3. Which are the various types of Spongilla found in nature?

After the discovery of sponges in the 1960s we have come to know about almost 200 species of sponges. To name some are Spongilla alba, Spongilla Arctica, Spongilla chaohuensis, Spongilla chenota , Spongilla mucronata, Spongilla helvetica, Spongilla wagneri, Spongilla permixta, Spongilla prespensis, Spongilla shikaribensis, Spongilla sarasinorum, Spongilla Stankovici, Spongilla wagneri, Spongilla lacustris, spongilla jiujiang ensis, Spongilla gutenbergiana, All these sponges have been identified by different discoverers who also have named them such as Linnaeus, Annandale, Carter, Weltner, Topsent, Hadzici, Sasaki, Arndt and many others.

4. What are the differences between Marine sponges and freshwater sponges?

Sponges can be found on the surface and beneath in every type of water bodies be it freshwater or marine. Among the 200 species yet identified and studied most of them are found in marine and brackishwater environments. As we all know the environment in vast oceans is harsher and experiences more diurnal variation. Moreover, the water contains more salt than freshwater. So the sponges of freshwater have developed gemmules which are now known to be the major difference between the two.

5. Are the sponges that we use in our daily lives the same as those of the organism Spongilla?

Sponges that we use in our daily lives are artificially created or manufactured in industries. Because it is a good absorbent of fluid so it comes in handy for cleaning up the liquid from various surfaces. The structure of these sponges is such that there are empty spaces inside it in which the water remains or gets soaked in. The body of living sponges or Spongilla also has similar structures and may have got the name actually according to the sponges we use. But because these living sponges are always inside the water or floating over it so all the spaces are filled up with water molecules and not Air.

6. Which chapter of Biology deals with the study about Spongilla?

Sponges as organisms have reserved a very special position in the taxonomic classification of unicellular and multicellular organisms in Biology. The entire phylum of Porifera under the kingdom of Animalia consists of sponges. And because sponges are multicellular organisms so they have got all the body parts essential for survival and performing different functions of the body. So these are studied under the chapter on the Biological classification of the organism. For a detailed study on this particular topic, resources are available on the Vedantu website.

7. Are the Information mentioned in the articles on the Vedantu website accurate?

Vedantu Online Courses is providing online education to students across India for the last couple of years. There are various products and resources available on the website to make the learning process more easy and effective as well as enjoyable. So it also provides the full description of every topic that the students get to know about in their course of study. The students who want to know more about any topic they come across while reading their course books with limited information, can search it on the website and get it downloaded in the PDF format too to refer to it in future. These resources are designed by the best of experts in their field and are thus, quite accurate and reliable. All these PDF articles are available free of cost to the students who have registered themselves on the portal.

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