Sponge Regeneration

the sponges most amazing ability

While it is no secret that certain animals can regenerate lost body parts, sponges are undoubtedly the best at it. As sponges can be cut up tiny pieces or even mashed up into a paste and as long as they have two special cells called collencytes (which produce mesohyl the gelatinous matrix in the sponge that forms a sort of psuedotissue) and archeocytes (which produce all the other cells in the sponges body) the sponge will survive and reform into the sponge it once was(although they will look different . As long as a fragment of a sponge has these two cells the animal can survive the most brutal of Injuries and in a few weeks be back to its normal filter feeding self. Making sponges one of the most awesome animals ever!

Image source

A stunning Chromodoris quadricolor (Nudibranchia - Chromodorididae) on Red Fire Sponge, Negombata corticata (formerly Latrunculia corticata).

Photo credit: ©Norbert Probst | Locality: Hurghada, Egypt, Red Sea

Yellow Tube Sponge

Aplysina fistularis

© moralcoral

The few species of demosponge that have entirely soft fibrous skeletons with no hard elements have been used by humans over thousands of years for several purposes, including as padding and as cleaning tools.

By the 1950s, though, these had been overfished so heavily that the industry almost collapsed, and most sponge-like materials are now synthetic.

Sponges and their microscopic endosymbionts are now being researched as possible sources of medicines for treating a wide range of diseases. Dolphins have been observed using sponges as tools while foraging.



and it is beautiful

A new species of sponge have been discovered in the Mediterranean by an international group of scientists, Sympagella delauzei is the name given to this new type of glass sponge (Hexactinelida), measuring 8 to 14 cm, is found at depths between 350 and 500 meters.

The study, published in the Journal of the Marine Biological Association of the United Kingdom, also details the recent discovery of some specimens near Atlantic areas such as mountains Gorringe in Portugal, although it is possible its distribution in other areas such as north Africa and Macaronesia

It has always been believed that the Mediterranean was not an environment conducive to the presence of glass sponges, as these are found in colder waters, being common in polar waters or at depths water environments. In the Mediterranean, even in the deepest areas, water temperatures barely drop below 13 C°. However, as demonstrated by this discovery, this sea still holds many secrets and surprises.


Xestospongia testudinaria

…a large species of Petrosiid barrel sponge that occurs in waters around the Philippines, Australia, much of the western and central Indian Ocean, Indonesia, Malaya and New Caledonia. Like other members of the genus Xestospongia X. testudinaria can grow quite large, but in intertidal zones they will grow significantly smaller (around 3-8 inches). Like other sponges X. testudinaria is a filter feeder and will filter the water around it for nutrients. 


Animalia-Porifera-Demospongiae-Haplosclerida-Petrosiidae-Xestospongia-X. testudinaria

Image(s): Albert Kok

Venus’s Flower Basket Glass Sponge | ©NOAA Okeanos Explorer Program, Gulf of Mexico 2012 Expedition

A spectacular group of Venus’s Flower Basket Glass sponges (Euplectella aspergillum)with a squat lobster in the middle, photographed in the Gulf of Mexico, North.

Euplectella aspergillum is a sessile animal that protrudes from the rocky ocean bottoms. Its skeleton contains hexactine (six-rayed) siliceous spicules and in addition contains a latticework of fused siliceous spicules. This is where is gets the name “glass sponge” because quite literally it is made of glass, making it the most exquisite example of the class Hexactinellida, but also as precarious and as brittle as glass can be.

One very unique feature about the E. aspergillum is that very often you can find some abyssal shrimp within the cavity produced by the lattice structure that makes up the sponge. Sometimes young male and female shrimp enter this cavity while they are still larva and over time they begin to feed and grow. The small shrimp grow and become too large to leave the silicon cavity of the sponge. It is customary in Japanese culture to give this elegant glass sponge away as a wedding gift symbolizing the wedding vow, “Till death us do part”.

Animalia - Porifera - Hexactenellida - Lyssacinosidea - Euplectellidae - Euplectella - E. aspergillum


Glass sponges (class Hexactinellida) are often no taller than 1 m, but they may grow together to form sponge reefs, reaching as great as 20 m in height. Many species inhabit relatively deep waters (200–2000 m) and are known for their beautiful, intricate patterns made of siliceous spicules. Sponges in this class are so fragile that when they are brought to the surface, their delicate forms usually collapse.

(Photo source(s))


A diver releases a harmless dye near the epidermis of the sponge, and the dye can be seen filtered out through the osculum.

The February issue of Conservation Biology is out, and it’s FREE! 

On the cover is a green sponge (Lubomirskia baicalensis), endemic to Lake Baikal, Russia. Worldwide sponges contribute to the function and integrity of marine and freshwater benthic communities, but the conservation status of only a minority of species is known. A lot of great content in the February issue. 

Venus’ Flower Basket - Euplectella aspergillum

This is the bleached skeleton of the Venus’ Flower Basket, Euplectella aspergillum, belonging to the small group of glass sponges (Hexactinellida - Euplectellidae), characterized by a skeleton composed of microscopic, silica spicules. 

The body structure of these animals is a thin-walled, cylindrical, vase-shaped tube with a large central atrium. The body is composed entirely of silica in the form of six-pointed siliceous spicules, which is why they are commonly known as glass sponges. Spicules are microscopic, pin-like structures within the sponge’s tissues that provide structural support for the sponge. These spicules ‘weave’ together to form a very fine mesh which gives the sponge’s body a rigidity not found in other sponge species and allows glass sponges to survive at great depths in the water column. Overlying the spicule framework there is more siliceous tissue called a syncytium which forms very fine fibres which look rather like a cobweb over the framework.

Venus’ Flower baskets are deep sea animals found in the western Pacific Ocean near the Philippine Islands.

References: [1] - [2]

Photo credit: ©Martyn L Gorman

What makes the 3 classes of sponges unique?

Imagine diving on a tropical coral reef and seeing all sorts of colorful sponges, some large, some small, some barrel shaped and some tube shaped. You might wonder: are all of these sponges functioning in a similar way? Do all sponges look like these? The answer is no, not even close.

There are three classes of sponges, all within one phylum called Porifera. Almost all of these filter water to obtain food - like the ones we focus on for our project exploring how sponges change the water chemistry on coral reefs - but some use a different life strategy altogether.

Sponges in all three classes have microbes that live within them as symbionts (symbionts are organisms of different types that live/exist together). This is an important relationship for sponges and an important concept for our project!

First, the class Demospongia comprises the largest and most widespread group of sponges and these are what people typically think of when they think of sponges. Demosponges have silica (glass) spicules that help give structure to the sponge body (like a skeleton) and protein fibers called spongin, which gives them a resilient quality. Demosponges come in all sorts of sizes, shapes and colors as shown in the photo below.

  • Photo courtesy of Saspotato on Flickr under the creative commons license 

They are found in tropical, temperate, polar, shallow, and deep water, and in freshwater. The sponges that were harvested (and still are on a smaller scale) for bathing belong to the genera Spongia and Hippospongia, are also a demosponges but these have no spicules.

  • Historical photo of sponge auction in Key West. Photo courtesy of Florida Sea Grant on Flickr under the creative commons license.

One unique demosponge I want to mention here is the carnivorous kind. Yes, I said carnivorous sponges! These typically live in deep water were there is less food in the water column. Theses sponges have hooked spicules that help them capture small crustaceans – like shrimp and amphipods, and even small fish! You can think of these as a sponge version of the venus fly trap plant.

The harp sponge is carnivorous and was discovered in 2012 off the coast of California at over 3,000 m depth by Monterey Bay Aquarium Research Institute. See more info here

Pictured below is one kind of carnivorous sponge, courtesy of NOAA photo library, that can trap small animals with filaments (typically seen with long filaments not shown here) that readily capture small animals that have fine hair-like appendages called setae.

  • NOAA photo library, creative commons license

The second class is Hexactinellida, or the glass sponges. These have silica spicules, which are often quite large and beautiful with 4 to 6 points on each spicule. The glass sponges are typically found in deeper waters (>1,000 ft or 300 m) and can form large reefs, such as found in deep water off the coast of British Columbia and Washington state.

Rather than pumping, these sponges rely on current to move water through their bodies so they can capture particles of food. They have a unique characteristic of being able to rapidly send electrical signals across their bodies so that they can respond to stimuli- perfect for grabbing that fast moving piece of detritus!

  • Venus’s flower basket glass sponge. Photo courtesy of NOAA photo library on Flickr under the creative commons license

One unique example of a glass sponge is the species known as Venus’s flower basket (pictured above). This sponge has a symbiotic relationship with a small shrimp. Two shrimp, one male and one female, live inside the sponge their entire lives. When the shrimp produce offspring (larvae), the larvae are released and travel to find another sponge to settle in. The shrimp get a great home with constant food supply and they help clean the sponge.

The last class is Calcareathe calcareous sponges. The spicules in these sponges are made of calcium carbonate rather than silica. These are less common than demosponges but still found in marine waters worldwide, even in shallow water that you might dive in.

The photo below is from a NOAA Ocean Exploration cruise that I participated in that was organized by researchers at The South Carolina Department of Natural Resources and the College of Charleston’s Grice Marine Lab. The lovely looking calcareous sponge we collected using the submersible The Johnson Sea Link II was from ~150 m depth off the coast of Georgia and South Carolina is pictured below (On the left side of the calcareous sponge is another kind of sponge).

This guest-post is written by Cara Fiore (@clfiore). 
Cara is a post-doctoral researcher at Woods Hole Oceanographic Institute. Among other things, she studies how sponges influence water chemistry in reefs (and elsewhere). You can learn about her ongoing research at experiment.com/sponges.


Chalice Sponge (Heterochone calyx)

Also sometimes known as the Goiter Sponge, the Chalice sponge is a species of glass sponge (Order: Hexactinellida) that occurs in deep off of the western seaboard of North America. Heterochone calyx is commonly seen growing in large “forests” on the upper portions of seamounts, where currents concentrate food particles.  Like most sponges H. calyx is a filter feeder and will filter the water around it for nutrients. 


Animalia-Porifera-Hexactinellida-Hexasterophora-Hexactinosida-Sceputrulophora-Aphrocallistidae-Heterochone-H. calyx



Pink Tube Sponge  Haliclona mediterranea

Haliclona mediterranea is a species of encrusting sponge with fleshy body, but soft and delicate, in the form of small cones on top, which can have a maximum height of 8 cm. Its color is quite striking, pink or purple. This sponge lives in caves or rocky bottoms, at depths between 10 and 50 m, but almost always in dark or protected from direct light.

This species is distributed in the Aegean Sea, western Mediterranean, and also some localities in the North Atlantic Ocean.

[Animalia - Porifera - Demospongiae - Haplosclerida - Chalinidae - HaliclonaHaliclona mediterranea Griessinger, 1971]

References: [1] - [2]

Photo credits: [Top: ©Giuseppe De Cristofaro | Locality: Bacoli, Punta Pennata, Italy, 2011] - [Bottom:  ©Giorgio | Locality: Monte Argentario, Tuscany, Italy, 2006]