Sponges — simple aquatic animals with dense, however porous, skeletons — are highly adjusted to your environments.

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A range of sponges period the seascape that Flower Garden banks National marine Sanctuary. From round to encrusting to branching, the colors and textures that sponges add to the intricacy of the reef. Credit: G.P. Schmahl


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Sponges are discovered in a wide variety of colors, shapes, and also sizes and also are frequently mistaken for plants. Scientists believe that their varied colorations may safeguard them native the sun’s harmful ultraviolet rays.


Sponges have been around for a really long time, v certain varieties having a fossil document that dates back approximately 600 million years to the faster (Precambrian) duration of earth’s history. The roughly 8,550 life sponge species are scientifically divide in the phylum Porifera, i m sorry is made up of four distinct classes: the Demospongiae (the most diverse, include 90 percent of all living sponges), Hexactinellida (the rare glass sponges), Calcarea (calcareous sponges), and also Homoscleromorpha (the rarest and also simplest class, only newly recognized, with roughly 117 species).

While sponges, prefer corals, room immobile aquatic invertebrates, they space otherwise totally different organisms with unique anatomy, feeding methods, and also reproductive processes. The main distinctions are:

Corals room complex, many-celled organisms. Sponges are very simple creatures with no tissues.All corals require saltwater to survive. While many sponges are uncovered in the ocean, numerous varieties are also found in fresh water and also estuaries.

Regardless of these differences, sponges are vital inhabitants of coral reef ecosystems. A diverse sponge population can impact water high quality on the reef as the sponges filter water, collect bacteria, and procedure carbon, nitrogen, and phosphorus. In nutrient-depleted coral reefs, part sponge species are believed to make carbon biologically available by excreting a type of “sponge poop” that other organisms feed on, thereby fueling productivity throughout the ecosystem. In this way, sponges protect the reef against extreme fluctuations in nutrient density, temperature, and also light, benefiting the survive of other reef organisms.

A sponge’s skeletal form adapts fine to its specific habitat, enabling it come live ~ above hard, rocky surfaces or soft sediments such together sand and mud. Some sponges even attach themselves to floating debris! hardly ever are they found fully free-floating.

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As water filters with a sponge’s porous exterior, the sponge gains part motion, receive food and also oxygen, and also dispels waste. Inside the sponge, tiny hairlike structures dubbed flagella create currents come filter bacteria the end of the sponge’s cells and trap food within them. Their strong skeletal structures help sponges stand up to the high volume the water the flows through them every day.