Marine Sponges

Marine sponges are sessile animals that look like plants. They attached themselves to a rock, shell or seafloor when they are young and there live for the rest of their lives. They filter water through their porous body for the food they eat. They eat bacteria and other particles floating in the water as it moves through their body. They live on the seafloor in tide pools and the ocean floor after the larvae attaches itself to a surface where they live the rest of their life. Some sponges have been found living on ocean floors that are up to 8,800 meters (5.5 miles) deep.

Branching tube sponge, NOAA

Branching tube sponge, NOAA

5,000 species of sponges
There are over 5,000 named species with 99% of them living in salt water. Most marine sponges live in warm tropical waters. The fertilized eggs of sponges form larvae which live as plankton until they find a suitable place to settle and grow into an adult sponge.

Simplest multicellular animals
Sponges are the simplest of multicellular animals with bodies full of pores. They do not have heads, arms or internal organs. Instead, they have water flowing through their body up to 20,000 times their own volume each day. The water contains plankton, bacteria and oxygen they need to survive.

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How sponges filter water
The water is pulled into the sponges bodies through tiny pores that cover the outer surface of their body. Cells inside their body filter food from the water. Flagella pushes the water through canals in one direction as the sponges get their nutrition and oxygen before the water exits their body at another opening the oscula. The oscula is a large opening in the sponge’s body.

Phylum Porifera
All marine sponges belong to phylum Porifera. They come in a wide variety of shapes, sizes and colors. Some marine sponges form encrusting sheets on rocks while other create volcano-shaped mounds. Their tubes that the water flows through can be as small as one millimeter or as large as one meter. Their colors include gray, red, yellow and blue. Algae grows on some of them giving them a green color.

Organic carbon eating sponge
A marine sponge that lives in deep cavities in coral reefs gets its nutrition from organic carbon that is inedible to most coral reef inhabitants. The sponge absorbs and uses 50% of its body weight each day to make new cells.

Sponges recycle organic carbon
Researchers found the sponges didn’t grow in size but instead shed a large number of cells each day that provided nutrients for other coral reef inhabitants. The sponges are essentially recycling organic carbon that is used by other reef inhabitants.

Chemical compounds produced by sponges
Sponges are also being studied by biologists because many species have developed a wide variety of chemical compounds to protect them from their enemies. Sponges have been found to produce more elaborate compounds than any other animals living around coral reefs.

Sponges use chemical warfare
Many of these chemical compounds are used as a type of chemical warfare against other animals that are encroaching on where they live. Today scientists are hoping to use some of these chemical compounds to combat human cancers and to use them in other medicines that fight bacterial diseases.

More information about the oceans

The Oceans on our planet cover approximately 70% of the Earth. The water that covers our planet is essential to life on our planet. From space the Earth looks like a blue ball partly covered with white wispy clouds.

The Great Barrier Reef off the coast of Australia are one of the seven great wonders of the natural world. Find out more about this World Heritage Site.

The Mid Atlantic Ridge is a divergent plate boundary where continental plates are moving apart down the middle of the Atlantic Ocean.

Viperfish are one of the fiercest predators living in the deep ocean. Find out how they attract their prey with a “fishing lure” and impale their prey with fang-like teeth.

Oceanic Zones are specific areas of the ocean. Most ocean life lives in one specific zone. Marine biologists have discovered some animals, whales, can dive to great depths to hunt for food.

The 2004 Indian Ocean Tsunami lifted the seabed and moved it sideways along a 1,600 km (1000 mile) crack in the Earth’s surface. The Indian Plate slipped beneath the Burma Plate during the earthquake.

Rift Valleys are not caused by erosion but are created by tectonic activity. These valleys form when oceanic plates are moving in different directions forming a divergent boundary.

Marine Sponges are sessile animals that look like plants. Some sponges have been found living on the ocean floors that are over 8,800 meters (5.5 miles) deep.

Caribbean Spiny Lobsters are found in tropical and sub-tropical waters. They are also known as Florida spiny lobsters and are famous for their migration each year into deeper waters.

Rogue Waves for centuries were believed to be tall tales sailors told during shore leave. They said waves rose out of the sea as a vertical wall of water that crashed into a ship without warning.

Ghost Crabs live on beaches in tropical and sub-tropical regions. They are found along beaches from Rhode Island south to Brazil. They only need to wet their gills to live on land.

Black Smokers (hydrothermal vents) were discovered by scientists aboard the Alvin in 1977. An entire ecosystem lives around the chimneys with bacteria the base of the food chain.

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