Toby Modebelu (TM)

silica sponge.jpg spongebob.jpg

Basic anatomy of the silica sponge (7) (AA)
Basic anatomy of the silica sponge (7) (AA)

Classification/Diagnostic Characteristics:
Kingdom: Animalia
Phylum: Porifera
Class: Hexactinellida
Order: Lyssacinosida
Family: Euplectellidae
  • Hard skeletal elements called spicules made of hydrated silicon dioxide
  • No specific tissue types
  • Lives in mostly marine environments
  • No Nervous System
  • One of the simplest multicellular organisms (8)(KG)
  • Covered with tiny pores called ostia, which lead to an internal system of canals. These canal holes are lined with ciliated cells that sweep in water and nutrients.(8)(KG)

Biologists speculate that sponge choanocytes, or sponges that contain flagella, are very similar to the choanoflagellate cells that lived in late Precambrian seas. Biologists believe that this molecular evidence indicates that the ancient choanoflagellates are close relatives of all animals and are potentially a close relative to the common ancestor of all life on earth. (2)(BB-V)
Relationship to Humans:
Human pollution has led to a decline in the sponge population. Sponges were once used as material in helmets. The usage of sponges in helmets was to make the helmet softer and more comfortable. Skeletons of dead sponges are used by humans as a body washing tool.

Another name for this sponge is Venus' Flower Basket. In traditional Asian cultures, this particular sponge (in a dead, dry state) was given as a wedding gift because the sponge symbiotically houses two small shrimp, a male and a female, who live out their lives inside the sponge. They breed, and when their offspring are tiny, the offspring escape to find a Venus Flower Basket of their own. The shrimp inside the basket clean it and, in return, the basket provides food for the shrimp by trapping it in its tissues and then releasing wastes into the body of the sponge for the shrimp. (6) (MC)

Habitat and Niche:
Sponges can be found in aquatic environments. They can be found on ocean floors in most places around the world. Most sponges are located in shallow water along the coast and some are found very deep in the ocean where disturbance is kept at a minimum
Sponges are essentially a water filtering system for the ocean due to their water canal system.
Sponges feed by filtering tiny particles of food out of the water in which they live.(HSC)
Predator Avoidance:
The habitat of sponges allows it to avoid most of its predators. The depth of the ocean floor gives sponges the ability to go undetected by predators.

Many sponges shed spicules, tiny spike-like structures, to create a barrier that echinoderms (including sea stars and sea urchins) can't pass. Those echinoderms, without the shield of spicules, would be able to prey on the sponge. Also most sponges secrete toxins so as not to allow other sessile (fixed in one place, immobile) creatures from growing on or near them. (5) (BH)

Many of the sponges greatest threats are micro organisms and pathogens in the water around the sponge. Sponge with its many pores seems susceptible to infection by pathogens. Each cell in the sponge is capable of recognizing and defending itself with chemicals that are cytotoxic as well as antibiotic. By releasing these chemicals in controlled amounts the sponge is capable of manipulating the the types and the amount of micro organisms that attempt to invade them. Most sponges actually keep a steady amount of bacteria that are beneficial to the sponge inside of them similar to the humans intestine. (10) (DA)

Nutrient Acquisition:
Sponges remain stationary which causes for difficulty in acquiring nutrients. They feed on food particles that are in the water at their ocean level. A few species of sponges are carnivorous and trap their prey using their spicules as a hook.

Although adult sponges are sessile (they cannot move), they have evolved efficient means of acquiring nutrients. Flagellated cells called choanocytes on the interior of the cell use their flagella to pump water through the pores on the sides of the sponge, into the interior of the sponge, and out through the top opening of the sponge called the osculum. The flowing water allows the sponges to capture and ingest food particles, thus providing the sponge with the sustenance it needs to survive. [1] (FZ)
Reproduction and Life Cycle:
Sponges reproduce both sexually and asexually. Budding and regeneration are the two methods of asexual reproduction for sponges. Most species of sponges have the ability to produce eggs and sperm but don’t have the ability to self-fertilize. Because of this, water currents usually transport sperm from one sponge to another.

In asexual reproduction more specifically budding, a sponge has buds from the parent and the buds grow into sponges. This can happen since archaeocytes , a distinct type cell, allows the buds to grow into sponges.(9)(NC)

Fertilization occurs internally and planktonic larvae are released and float in the water for a few days until they settle and start growing. (8)(KG)

In freshwater sponges, when conditions become harsh or unfavorable such as cold temperatures, sponges produce asexual gemmules, super-resistant (to drying, freezing, lack of oxygen, etc.) buds which don't open up until conditions become favorable again, such that they will grow back even if the parent sponges dies. (13) (DM)

sponge cycle.1
Reproduction and life cycle of sponges (12) (WSS)
sponge development.png(PS)(14)

Growth and Development:
Sponge larvae float around after fertilization and then lodge itself somewhere and start to grow.
Silica Sponges have hard skeletal spicules made of hydrated silicon dioxide.
The silica sponge allows light to be reflected off of it making it look as though it is glowing. This is because the silica rods they are made of are glass like and as soon as light hits the rods, it is reflected inside the rods making them glow. (LC) 1

Sponges remain stationary.
Sensing the Environment:
Sponges have no cell specialization, additionally they have no nerves or muscles, but each individual cell has the ability to sense changes in the environment. (ES)

Gas Exchange:
Sponges have a water canal system. They take in water and food particles form the ocean then have a series of filter chambers which provides oxygen and removes carbon dioxide.

All over the sponge are small pores, called ostia. Ostia draw water into them, and circulate it throughout its body by the action of cells called choanocytes. These choanocyte cells contain whiplike structures called flagella, that move around and push water through the sponge. As water is drawn in and then and out of the sponge, food and oxygen are brought to the sponge and waste and carbon dioxide removed.(4)(CC)

Waste Removal:
Sponges remove waste by using their water canal system which excretes wastes after the waste has gone through the filter chambers.
Environmental Physiology:
Most species of sponges are marine. Their environment is the ocean floor. A small number of species live in fresh water.

Internal Circulation:
Because sponges do not have tissues or organs, but rather individual cells that work together to keep the organism alive, there is no clear internal circulatory system. Instead, they utilize amoiboid cells located within the wall structures. Amoiboid cells transfer materials from to cells. For example, an amoiboid cell make intake some nutrient and move to a non-food-collecting cell and give the cell the food. [11] (AY)

Chemical Control:
Review Questions:
1. What is the significance of sponges pores? Describe two ways that a sponge's pores are an integral part of their being. (SJ)
2. What are 2 products that humans have used the bodies or skeletons of sponges for? (JLev)
3. Why does the sponge have a "glowing" appearance? (E.S.S.)
4. Describe the adaptations of sponges to their sessile states. (AWC)
5. When disturbed, how does the sponge respond in its environment? (JLau)
6. How can sponges reproduce both sexaully and asexually? (SM)
7. What are choanocytes and what is their purpose? (BS)

Works Cited:

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