Kingdom:Animilia
Phylum:Porifera
Class: Either Demospongiae or Hexactinellida.
The sponge is part of the animal kingdom and is the oldest animal that still lives today. It was the first of the animal species to evolve from the common ancestor. It has a very basic structure and in general carries out very basic functions. Sponges were excluded from the Bilateria group because they do not have distinct tissue types. Also they are characterized by hard skeletal elements called spicules. The general body plan of the sponges is an aggregation of cells built around a water canal system. Also sponges have an extracellular matrix hat is composed of collagen, adhesive glycaproteins, and other molecules that hold the cell.
Relationship to humans
In the last two decades there has a been a significant rise of sponge aquaculture specifically by many third world countries. People use bath sponges for taking showers and scrubbing their skin. The sea sponge is additionally used for painting and household cleaning, however; artificial sponges are more efficient and have diminished their importance. Sponges are also an ingredient in antibiotics and cancer inhibiting drugs. (4) Also supposedly bottlenose dolphins in Shark Bay in Western Australia will attach marine sponge to its rostrum(the back of its snout) which supposedly protects the dolphin when it searches for food in the sandy bottom. This unique behavior is only exhibited by females in this specific bay.
Habitat and niche
Most sponge species live in the oceans, but a few do live in freshwater. They are normally found at the bottom of the ocean. Most sponges live in clear, calm waters where sediment doesn't get into their pores, which will both prevent the sponge from getting food and from breathing. Sponges that live in intertidal or shallow water are subject to strong waves and attach firmly to the substrate. Sponges that live in flowing water are flattened and are oriented at right angles to the direction of current flow, allowing them to intercept water and the food it contains as it flows past them.
Predator avoidance
One of the sponge's predators, the Sponge fly.
Silica sponges have hard mineral spicules in their skeletons. These siliceous (glass) spicules help keep the sponge rigid and provide defense by decreasing digestibility of the sponge. Additionally, the tough tissue is irritating to the mouth parts and guts of predators that attempt to consume the sponge. (6)
Even though silica sponges are sedentary animals and cannot swim away from any incoming predators, they are able to protect themselves by secreting poisons as their main weapon of defense. These poisons are believed to taste bad and smell bad to predators and therefore, they are driven away from the sponge. A cool fact though is that in the last two decades, these poisons and other biochemicals inside sponges have received special attention as potentially useful drugs for treatment of cancer and other diseases. (5)
Nutrient acquisition
Sponges are filter feeders. They draw water in through the pores located throughout their body wall into a central cavity (1).The water in the ocean or freshwater enter the sponge along with the food particles in it, by way of small pores and pass into water canals(a central atrium) where choanocytes capture food particles. Once captured, food is digested in food vacuoles or transferred to the amoeboid cells in the middle layer of the body wall for digestion (1). Choanocytes, the cells that make up the interior body walls of the sponges, have a flagella surrounded by a collar of microvilli, membrane protrusions that increase the surface area of the cells. The beating of the flagella pumps water carrying nutrients through the sponge, and the microvilli absorb the nutrients. (9)
Reproduction and life cycle
Sponges can reproduce both sexually and asexually. In sexual reproduction, a single sponge will produce both the eggs and sperm but the sponge will not self-fertilize. The water the sponge lives in will carry sperm from one individual sperm to another. Larvae develop from an egg that is fertilized. A larva will then swim around until it attaches onto an object. It later develops into a new sponge. In asexual reproduction, either buds or gemmates break from parents and develop into new sponges (budding) or regeneration occurs. (4). A sponge has both male and female reproductive organs ().
Growth and development
After sexual reproduction, the zygote divides by mitosis to form a hollow sphere called a blastula. The blastula enters the mobile larval stage and develops flagellum as it becomes an amphiblastula larva. Eventually the larva settles down and undergoes metamorphosis as the flagellum develop into collar cells (10).
Integument
The outside of a sponge is very rough and hard. It is made up of three layers: outer, middle, and inner. The outer layer consists of flat epidermal cells; the middle layer is composed of a gelatinous substance and amoeboid cells; the inner layer is made up of flagella and collar cells also called choanocytes (1). The epidermal cells, pinacocytes, are thin, leathery and tightly packed together. (9)
Movement
Adult sponges are sessile and do not move. However, the larva which are released into the water after sexual reproduction possess cilia which they use to swim through the water. Eventually these larva attach to a surface and grow into adult sponges. (7)
Sensing the environment
The sponge body is different than most animals because it constantly changes its shape to fine-tube to its filter feeding system. This change is done by the amoeboid movement(like an amoeba's) of cells inside the sponge, and they change from one form to another. Sponges have no legitimate nervous system, since they hardly have any cell diversification. Although they do have many of the same enzymes and proteins we use in our own nervous systems. Even though
they don't have a nervous system, some sponges will actually contract if their body is touched. (11)
Gas exchange:
Respiration starts when the water around the sponge makes contact with the pinacocytes on the outermost layer of the sponge. Then the water is then absorbed through the pores when the morocytes, the small muscles, open them. Choanocytes, flagellated structures, absorb the oxygen. Archaoecytes move the oxygen through the tubes to other parts of the sponge. The rest of the oxygen is directly taken in by the cell membranes of the sponge. The unnecessary or leftover water and gases are pumped through the atrial cavity and out the osculum.(6)
Waste removal:
The sponges are very thin considering their walls only consist of two cell layers. This allows the cells of the sponge to directly remove waste into the environment and maintain homeostasis. Sponges don't have a mouth or an anus, hence they don't have a very sophisticated excretory system. Their waste is removed in one of three different ways: diffusion, osmosis, and cell transport. Porifera have spores on the outer cell layer of their body, which allows them to excrete their waste. Also they have an oscula, which is the large opening that the waste goes through.(2)
Environmental physiology (temperature, water and salt regulation)
Sponges live in environments that they have already been acclimated or can acclimate to.
Internal circulation
Water enters the organisms through the pores, and the nutrients are absorbed individually by cells (3). Since there are only two layers of cells the transport between different cells is easy and doesn't really have an organized system.
Chemical control (i.e. endocrine system)
Sponges lack chemical control/endocrine system.
Review Questions
1. How do sponges reproduce both asexually and sexually?
2. What are the different ways that these stationary sponges protect themselves?
Silica sponge (porifera)
Table of Contents
Classification/Diagnostic characteristics
Kingdom:Animilia
Phylum:Porifera
Class: Either Demospongiae or Hexactinellida.
The sponge is part of the animal kingdom and is the oldest animal that still lives today. It was the first of the animal species to evolve from the common ancestor. It has a very basic structure and in general carries out very basic functions. Sponges were excluded from the Bilateria group because they do not have distinct tissue types. Also they are characterized by hard skeletal elements called spicules. The general body plan of the sponges is an aggregation of cells built around a water canal system. Also sponges have an extracellular matrix hat is composed of collagen, adhesive glycaproteins, and other molecules that hold the cell.
Relationship to humans
In the last two decades there has a been a significant rise of sponge aquaculture specifically by many third world countries. People use bath sponges for taking showers and scrubbing their skin. The sea sponge is additionally used for painting and household cleaning, however; artificial sponges are more efficient and have diminished their importance. Sponges are also an ingredient in antibiotics and cancer inhibiting drugs. (4) Also supposedly bottlenose dolphins in Shark Bay in Western Australia will attach marine sponge to its rostrum(the back of its snout) which supposedly protects the dolphin when it searches for food in the sandy bottom. This unique behavior is only exhibited by females in this specific bay.
Habitat and niche
Most sponge species live in the oceans, but a few do live in freshwater. They are normally found at the bottom of the ocean. Most sponges live in clear, calm waters where sediment doesn't get into their pores, which will both prevent the sponge from getting food and from breathing. Sponges that live in intertidal or shallow water are subject to strong waves and attach firmly to the substrate. Sponges that live in flowing water are flattened and are oriented at right angles to the direction of current flow, allowing them to intercept water and the food it contains as it flows past them.Predator avoidance
Silica sponges have hard mineral spicules in their skeletons. These siliceous (glass) spicules help keep the sponge rigid and provide defense by decreasing digestibility of the sponge. Additionally, the tough tissue is irritating to the mouth parts and guts of predators that attempt to consume the sponge. (6)
Even though silica sponges are sedentary animals and cannot swim away from any incoming predators, they are able to protect themselves by secreting poisons as their main weapon of defense. These poisons are believed to taste bad and smell bad to predators and therefore, they are driven away from the sponge. A cool fact though is that in the last two decades, these poisons and other biochemicals inside sponges have received special attention as potentially useful drugs for treatment of cancer and other diseases. (5)
Nutrient acquisition
Sponges are filter feeders. They draw water in through the pores located throughout their body wall into a central cavity (1).The water in the ocean or freshwater enter the sponge along with the food particles in it, by way of small pores and pass into water canals(a central atrium) where choanocytes capture food particles. Once captured, food is digested in food vacuoles or transferred to the amoeboid cells in the middle layer of the body wall for digestion (1). Choanocytes, the cells that make up the interior body walls of the sponges, have a flagella surrounded by a collar of microvilli, membrane protrusions that increase the surface area of the cells. The beating of the flagella pumps water carrying nutrients through the sponge, and the microvilli absorb the nutrients. (9)Reproduction and life cycle
Sponges can reproduce both sexually and asexually. In sexual reproduction, a single sponge will produce both the eggs and sperm but the sponge will not self-fertilize. The water the sponge lives in will carry sperm from one individual sperm to another. Larvae develop from an egg that is fertilized. A larva will then swim around until it attaches onto an object. It later develops into a new sponge. In asexual reproduction, either buds or gemmates break from parents and develop into new sponges (budding) or regeneration occurs. (4). A sponge has both male and female reproductive organs ().Growth and development
After sexual reproduction, the zygote divides by mitosis to form a hollow sphere called a blastula. The blastula enters the mobile larval stage and develops flagellum as it becomes an amphiblastula larva. Eventually the larva settles down and undergoes metamorphosis as the flagellum develop into collar cells (10).
Integument
The outside of a sponge is very rough and hard. It is made up of three layers: outer, middle, and inner. The outer layer consists of flat epidermal cells; the middle layer is composed of a gelatinous substance and amoeboid cells; the inner layer is made up of flagella and collar cells also called choanocytes (1). The epidermal cells, pinacocytes, are thin, leathery and tightly packed together. (9)Movement
Adult sponges are sessile and do not move. However, the larva which are released into the water after sexual reproduction possess cilia which they use to swim through the water. Eventually these larva attach to a surface and grow into adult sponges. (7)Sensing the environment
The sponge body is different than most animals because it constantly changes its shape to fine-tube to its filter feeding system. This change is done by the amoeboid movement(like an amoeba's) of cells inside the sponge, and they change from one form to another. Sponges have no legitimate nervous system, since they hardly have any cell diversification. Although they do have many of the same enzymes and proteins we use in our own nervous systems. Even thoughthey don't have a nervous system, some sponges will actually contract if their body is touched. (11)
Gas exchange:
Respiration starts when the water around the sponge makes contact with the pinacocytes on the outermost layer of the sponge. Then the water is then absorbed through the pores when the morocytes, the small muscles, open them. Choanocytes, flagellated structures, absorb the oxygen. Archaoecytes move the oxygen through the tubes to other parts of the sponge. The rest of the oxygen is directly taken in by the cell membranes of the sponge. The unnecessary or leftover water and gases are pumped through the atrial cavity and out the osculum.(6)Waste removal:
The sponges are very thin considering their walls only consist of two cell layers. This allows the cells of the sponge to directly remove waste into the environment and maintain homeostasis. Sponges don't have a mouth or an anus, hence they don't have a very sophisticated excretory system. Their waste is removed in one of three different ways: diffusion, osmosis, and cell transport. Porifera have spores on the outer cell layer of their body, which allows them to excrete their waste. Also they have an oscula, which is the large opening that the waste goes through.(2)Environmental physiology (temperature, water and salt regulation)
Sponges live in environments that they have already been acclimated or can acclimate to.Internal circulation
Water enters the organisms through the pores, and the nutrients are absorbed individually by cells (3). Since there are only two layers of cells the transport between different cells is easy and doesn't really have an organized system.Chemical control (i.e. endocrine system)
Sponges lack chemical control/endocrine system.Review Questions
1. How do sponges reproduce both asexually and sexually?2. What are the different ways that these stationary sponges protect themselves?
References
1. http://animals.about.com/od/sponge1/p/porifera.htm2. http://www.mhhe.com/biosci/genbio/maderbiology7/graphics/mader07b/online_vrl/images/0574bl.jpg (picture)
3. http://www.mcwdn.org/Animals/Sponges.html
4. http://animal.discovery.com/marine-life/sponge-info.htm
5. https://www.ebiomedia.com/prod/BOsponges.html
6. www.int-res.com/articles/meps/195/m195p125.pdf
7. http://tolweb.org/treehouses/?treehouse_id=4291
8. http://a-z-animals.com/animals/sponge/
9. http://www.ucmp.berkeley.edu/porifera/pororg.html
10. http://siera104.com/bio/porifera.html
11.http://faculty.washington.edu/chudler/invert.html
12. Textbook