4.+Porifera

Porifera - Zack Agelas clathrodes



More than 9000 species. They are the simplest multicellular animals. Three main types of sponges: glass sponges, demosponges, and calcareous sponges Agelas clathrodes have a red-orange color and are paler internally. (2) Tissues and organs are absent. Develops a thickness of no greater to 10 cm thick decorated with many small holes (especially on the side away from the current) Flesh is firm and tough and rough to the touch
 * Classification/Diagnostic Characteristics:**

Are related to humans in that both species share gene regulation, as histone-based gene regulation is used in sponges and humans. ([|7])
 * Relationship to Humans:**

All live in aquatic environments, the vast majority live in the ocean. They inhabit reefs and walls while preferring areas with some water movement. (2) Agelas clathrodes are common to Florida, the Bahamas and the Caribbean (2)
 * Habitat and Niche:**

Have a toxic substance that they use to prevent predators from eating them. Its bright color is an indication to predators that it is very bitter
 * Predator Avoidance:**

They are filter-feeders, meaning they move food-containing water through their bodies, either to a central opening, or a series of channels, and absorbed the food using specialised food absorbing cells called choanocytes.
 * Nutrient Acquisition:**

Both sexually and asexually
 * Reproduction and Life Cycle:**
 * Generally, individuals produce both sperm and eggs but don't self-fertilize. Water current carries sperm from one to another.
 * Asexually, through budding
 * Agelas clathrodes has both the reproductive organs of both males and females and as such is known as a hermaphrodite and will produce both sperm and eggs over a short reproductive period. In the process of releasing both the eggs and sperm, the eggs are fertilized and develop into larvae while covered with other cells that are thought to provide a food source to the larvae once it emerges from the egg. Agelas clathrodes studied in Curacao over a two year period demonstrated limited reproductive activity. The species also reproduces asexually, often when the sponge has a piece broken off which drifts to another location on the ocean floor where the piece will grow to adulthood.
 * Some reproduce by producing gemmules
 * Gemmules are cyst-like spheres that are made by wrapping shells of spongin around clusters of special amoeba-like cells called archeocytes that are full of nutrients and often reinforced with spicules ([|3])

Egg cells are fertilised within an adult sponge. They then develop into a larval stage, with cilia to propel them to a new habitat. They eventually land, and develop into a juvenile, and then an adult([|4]). spicules are structures that give them form. size range from 1 m to 2 mm
 * Growth and Development:**

Flesh is tough and resilient, and firm while the surface is rough in texture. (1)
 * Integument:**
 * Structure of a sponge:
 * water flows through the ostia, which are tiny holes in the outer boundary that act as mouths
 * cells inside the atrium, the hollow inside of the sponge, filter nutrients from the water as it is pumped through the body
 * water flows out of the sponge body through the Osculum, the large external opening at the top of the sponge

Not possessing any muscles that would allow it to move, the elephant ear sponge remains fixed to a substrate for its entire life, only covering new area through growth. However, parts of the sponge might detach and flow away from the parent, finding a new surface to attach to and grow on, essentially allowing the species to reproduce asexually despite its hermaphroditic nature. ([|1])
 * Movement:**

Porifera, sponges, lack a nervous system; however, they are still able to sense external stimuli. Porifera undergo a mechanism called the inflation/contraction response when they filter feed. During this mechanism, the Porifera's pores fill with water, and when the osculum, feeding pore of the organism accumulates many unwanted particles, they contract rapidly to expel the particles out with unwanted water. Calcium peaks inside the sponge's cells cause the sponge's flow of water to change, and the change in fluid flow rate causes the sponge to contract, proving that even without a sensory system, a sponge can interact with its environment. ([|10])
 * Sensing the Environment:**

Respiratory system is absent. Diffusion through the exterior cells is the means through which gas exchange happens. Sponges have porous canals throughout their bodies in which water can flow through. ([|5])
 * Gas Exchange:**

They allow water to flow through sponges and the water provides food and oxygen along with means for waste removal. Cells in the sponge's walls filter oxygen and food (bacteria) from the water and diffusion to get rid of their metabolic waste. (__ [|5] __) ([|6])
 * Waste Removal:**

Porifera live in water, from the deepest seas to the shallowest coasts most species are marine, can be found in all oceans 3% live in fresh water //A. clathrodes// are found in the ocean at depths ranging from 8.5 m to 110 m below the surface, at temperatures from 23.534°C to 27.388°C. The concentration of oxygen in their habitats is 4.543 mL/L to 4.854 mL/L, and the salinity ranges from 35.339 PPS to 37.203 PPS.
 * Environmental P hysiology (temperature, water, and salt regulation): **

They do not have an internal circulatory system. They obtain oxygen by the constant flow of water through their bodies. (__ [|5] __)
 * Internal Circulation:**

Since they don't have a system for circulating hormones, Porifera don't have an endocrine system as we would think of it [|(14)], but they do have chemical pathways for signals to intracellular signaling ([|15])([|16])
 * Chemical Control (i.e. endocrine system): **

1. How do these organisms reproduce? How is it that the can reproduce both sexually and asexually? 2. What are agelas clathrodes' method of waste removal? Describe the process. 3.How does agelas clathrodes get nutrients from their environment? 4. Porifera don't have a nervous system, but different cells in their body do communicate with each other. How do they do this? 5.Describe the life cycle of a sponge
 * Review Questions:**

Hillis, David M. “Animal Origins and Diversity.” //Principles of Life //, Sinauer Associates, 2015, pp. 460–463. (1) https://www.britannica.com/animal/sponge-animal (2) https://thephylumporiferaproject.wikispaces.com/Orange+elephant+ear+sponge+%28Agelas+clathrodes%29 (3) http://www.mesa.edu.au/porifera/porifera01.asp (4) [] (5) https://sites.google.com/a/hillers.org/the-orange-elephant-ear-sponge/circulatory-and-respiratory-systems (6) https://collections.tepapa.govt.nz/topic/2419 (7) https://www.earthlife.net/inverts/porifera.html https://www.sciencedaily.com/releases/2017/04/170411104532.htm https://adlayasanimals.wordpress.com/2013/10/23/sponges-phylum-porifera/ (10) [] https://link.springer.com/article/10.1007%2FBF00301981 http://www.wetwebmedia.com/SpongePIX/Agelas%20clathrodes%20(1).jpg http://eol.org/pages/332694/details (14) https://endocrine4lifexhs.weebly.com/porifera.html (15) http://www.sciencedirect.com/science/article/pii/089203549090016L (16) https://www.ncbi.nlm.nih.gov/pubmed/2531072
 * Sources**

1. Agelas clathrodes can reproduce both sexually and asexually. They do not self-fertilize; however, they can asexually reproduce through a process called "budding". On the other hand, they can sexually reproduce because they typically produce sperm and eggs and the environment they live in promotes fertilisation. The water carries the sperm and egg and upon coming into contact, they are fertilised and develop into an organism. 2. Similarly to how they use their environment to reproduce, agelas clathrodes also use their environment as means of waste removal. Due to the fact that they do not have circulatory systems, these organisms allow water do diffuse freely into and out of their body. Through this diffusion, sponges prevent nutrients such as oxygen and bacteria from being removed while the metabolic waste materials directly diffuse out of their systems. 3. Agelas clathrodes takes advantage of the natural currents and allows food to come to them, filtering it out of the water once it does. 4. Porifera use ligand based signals, similar to hormonal systems in more complex organisms, though no formal system for distributing these chemical messengers exists. 5.After being fertilised, the sponge develops into a larva, which finds a new location and grows into a sessile adult sponge.
 * Answers to Review Questions:**