Sponges and Microorganisms

Scientific Classification
Common Name:
Genus Species:
Approx. 5,000 Species

Why sponge-symbiotic microorganisms?

There are presently almost 5,000 different species of sponges identified within the Porifera Phylum. “Pore-bearing” in reference to sponges external pores or tiny holes. Scientist suggests that this pore on the sponges’ skin enables sponges to extract oxygen and food for survival. In doing so, sponges are able to intake and outtake filtered water through the mesohyl for all of its cells. Sponges act as a variable resource for Caribbean Seas because of their rapid ability to filter water. For a long time, sponges were initially thought to be plants until 1795. After further investigation, scientist concluded that sponges are the simplest form of multi-cellular animals in the Earth’s ocean. However, they are not like Homo sapiens because they contain no internal organs. Instead, sponges are solely consisting of microscope cells that are invisible to see to the naked eye. Special cells function together to develop tissues to form the sponge basic structure. With the absent of internal organs, sponges are held together in two ways. First being spicules, tiny needles like that stick out from the sponge that enables tissue to stick together. Not only does spicules hold the sponge together with their bristle and sharp thread-like over the entire external surface, but spicules also acts as a the sponges’ defense mechanism. Secondly, sponges’ cells are able to regenerate themselves into their extract shape if broken apart. This unique characteristic allows sponges to maintain its overall structure.
Figure 1. Cross section through a typical marine sponge showing leuconoid morphology and internal cell types (adapted from Bergquist, 1978) The body of the sponge is organized around the system of pores, ostia, canals and chambers that guide the water current from the inhalent canals to the exhalent oscules (Fig. 1).
Unlike in the coral reef, sponges have just been recently link to symbiosis processes. Symbiosis is the ecological process in which two or more different species interact with each other. The symbiosis process can either have a positive or negative effect on the host and its symbiont. In the coral reef, the symbiosis process between the corals and its photosynthesis’ microbe dinogflagellates is easily identified. However, sponges’ symbiosis with microorganisms is not as clear; in fact, the general symbiotic relationship remains a mystery. Marine sponges are very abundant in biodiversity. With that in mind, marine sponges contain highly diverse and dense microbial communities. More than 10 bacteial phyle (including Proteobacteria, Actinobacteria, Nitrospira, Chloroflexi, Planctomycets, Cyanobacteria, Acidobacteria) have been found in sponges, as well as both major lineages of Archaea and a range of unicellular eukaryotes such as diatoms and dinoflagellates.[[#_ftn1|[1]]Scientists are able to acknowledge the potential microbe can have a positive or negative impact on the host for photosynthesis, anaerobic metabolism, food source, pathogens, and/or parasite. Speculation between sponge and microbe is endless because of the little information gathered.
As mention earlier, sponges are excellent filter feeders as water is constantly circulating within and without the sponges’ canals. Filter feeding can provide method to transfer microorganisms and organic particles in and out of the sponge. Filter feeding contributes to the amount of microbes living within the sponges and enhances the sponge/microbe symbiotic relationship. In particular, the symbiotic relationship between the two benefits the marine environment greatly. Sponges are important members of the shallow and deep salt-water communities. Two examples, which easily illustrated this symbiotic relationship, are both nutrients supply by the photosynthetic symbionts and active microbes are derived from the microbes. Therefore, sponges and their microorganism associations provide assistance against their competitors - marine corals.

What do we really know about sponge-microbe symbiotic associations?

In relation to corals, the sponges symbiotic relationships has currently been in the limelight. The recent awareness and curiosity of the sponge/microbe interaction has largely been motivated by the discover bioactive molecules (Taylor et al .. 2007).[[#_ftn1|[1]]] Thus, the recent studies of the symbiotic association have been focus in relation to their dense biodiversity and biogeography. Within the last decade along, two publications on microbial symbiosis in marine sponges (Taylor //et al.//, 2007a; Vogel, 2008) emphasize the importance of microbes to sponge function. Both articles determine the importance of high density and diversity of abundant microbes to enable sponge function.
Fig 2. The basic structure of a signal microorganism found in a marine sponge. Various microorganisms have been found in sponges. Microbes includes Proteobacteria, Actinobacteria, Nitrospira, Chloroflexi, Planctomycets, Cyanobacteria, and Acidobacteria.
The questions raised and answered in both publications:
1. The importance of the symbiotic relationship to the sponges’ ability to function in its surrounding.
2. The significance of microbial associations to sponges’ health and digestion leading towards possible contributions to diseases.
3. The sensitivity of the symbiosis ability to adapt to the changing environmental temperatures and conditions.

Examples of Microbes

THEONELLIDAE Theonella swinhoei Cebu. Mactan Island. Suba Basbas. Philippines.
There is an outstanding number of various microorganisms being found in sponges, Some of these microorganisms are determine to be
Proteobacteria, Actinobacteria, Nitrospira, Chloroflexi, Planctomycets, Cyanobacteria, Acidobacteria. The symbiotic microbial community is highly diverse in society presenting itself with numerous of different of shape and colors. One host sponge can possess up to a total volume of 40% of microorganisms. With that in mind, one host sponge can have multiples of different type of microbes at any given time. For example, a 1996 (Bewley et all … 1996) study showed the marine sponge T. swinhoei having multiples of different microorganisms at a given time. Through transmission electron microscopy, four distinct cell populations containing different microbes to be present in T. swinhoei. Eukaryotic sponge cells, unicellular heterotrophic bacteria, unicellular cyanobacteria and filamentous heterotrophic bacteria are the four microbes discover in marine sponge T. swinhoei.
The most common and refer to microorganism in the science field is cyanobacteria. Even though cyanobacteria are not closely related to algae, Cyanobacteria are often called “blue-green algae”. Cyanobateria most common characteristics are aquatic and photosynthetic; therefore, give the bacteria is nickname “blue-green algae”. Presenting it as an unicellular bacteria, but cyanobacteria have the ability to grow in colonies and cultured. In a recent study of sponges, cyanobacterial symbiosis were observed from the Red Sea’s coral reef using the acetylene reduction technique (Wilkinson and Frey). The acetylene reduction technique was use to determine the any nitrogen activity.
"Nitrogenase activity was detected in two sponges with cyanobacteria but not in a third with no cyanobacteria. This is the first demonstration of nitrogenase activity in an animal with symbiotic cyanobacteria. In two previous reports of nitrogen fixation in marine animals, the activity was attributed to bacteria in the gut."[[#_ftn1|[1]]

The study suggested that the symbiotic reaction between both the marine sponge and cynaobacteria has a positive effect
on the possibility to adapt to the changing environment. Although further studies are needed to determine cyanobacterial nitrogenase activity in sponges influencing nitrogen activity, it is possible the additional fixed nitrogen would be beneficial to sponges. The sponges’ nitrogen fixation would allow sponges to thrive more easily in topical waters. Tropical waters are presented to be low in available nitrogen and available nutrients. The excess amount of nitrogen fixation due to this symbotic relationship would benefit the sponges’ ability to grow.

Sponge-Microbe Association

Symbiosis is defined as two organisms living in a marital relationship. A symbiotic relationship solely depended upon the connection between the two organisms. Where in certain instance organisms cannot live or function correctly without its so-called “spouse”. Symbiosis is known to occur in extreme cases. Organisms that lived within other organisms is known to be extreme cases. Extreme cases may not often be associated with the three types of symbiosis parasitism, commensalism, and mutualism. The definition of symbiosis seemed to have a positive outcome for all organisms at hand; however, two of these three-symbiosis relationships provide a positive and negative relationship. Parasitism is a symbiosis in which one-organism benefits and the host does not. In this relationship, the host is harm and the parasite receives the most benefits. This one-way benefit system can be shown in similarly in the commensalism relationship. Where on species benefits and the other is neither hurt nor helped. Mutualism exemplifies the definition of symbiosis providing both partners benefits from the relationship

Marine Sponges
The sponge-microbe associations are represented through these three forms of symbiotic relationship –mutualism, commensalism, and parasitism. As mention earlier, the most widely know microbe symbiotic relationship between the sponge host and its symbiont is the sponges’ relationship with cyanobacteria. This symbotic relationship presents itself in a mutual relationship. A symbiosis relationship were both the host and the symbiont are both benefitted. The mutual relationship is identified by the cyanobacteria ability to provided nutrients to sponge and the sponge provides a protective shield for the bacteria. For example, cyanobacteria provide a source nutrient for its host that lives in tropical regions. Approximately 50% of the sponges
Thacker R W Integr. Comp. Biol. 2005;45:369-376 FIG. 3. Proportion of dry mass of L. chlorea and X. exigua lost after two weeks of shading. Open bars represent control sponges, while striped bars represent shaded sponges. Error bars represent one standard error. Shading generated a larger loss of mass in L. chlorea than in X. exigua. N = 10 in each treatment
energy is thrive from this association. Their energy requirement is fulfilled by the photosynthetic metabolism portion or cyanobacteria. The longetivity of sponges in gametes and larval stages and to the rapid growth of sponges to compete with other species (algae and coral) are achievable. The photosynthetic metabolism cyanobacterium provides an important source of nutrients and a defense mechanism for the sponge. A publication published by Robert W. Thacker represents an experimental study performed to show how cyanobacterial benefits the sponges. The marine sponge Lamellodysidea chloroea contains a significant amount of host-specific, filamentous cyanobacterium Oscillatoria spongeliae. The impact of cyanobacterial photosynthesis of L. chloroea hosts sponges were manipulated by the shading of the sponge-cyanobacteria associations. The hypothesis tested was derived directly from the mutual association. If cyanobacteria benefit their hosts, shading should reduce this benefit. With the use of partly shaded sponge, the result indicated that the shaded part of the L. Chloroea sponge lost more than 40% of its initial region. However, the illuminated half of the sponge did not have any changes. Therefore, these results indicated that photosynthesis of cyanobacteria has significant effects on growth of sponges.
[[#_ftn1|[1]]With that in mind, the studied also suggested that cyanobacteria in marine sponges could bombard host sponges if there is no control over the growth of cyanobacteria. Thus, host sponges are believed to have a controlling mechanism to inhibit the growth of cyanobacteria, for example, starving the symbiont.

FUN FACTS[[#_ftn1|[1]]

1. Many sponges, especially coral reef species, have a mutualistic symbiosis with bacteria
and cyanobacteria. The sponge provides a home for the bacteria and algae. The cyanobacteria provide the sponge with nutrients from photosynthesis, which increases sponge growth rate and competitive ability. Sponges can also gain nutrition from bacteria.
2. In Antarctica, sponges comprise 75% of the benthic biomass at 100–200 m (328–656 ft.) depths.
3. The tropical encrusting sponge, Terpios, grows on living and nonliving substrates including corals, hydrocorals, molluscs, and algae. It grows an average of 23 mm (0.91 in.) a month. Experiments have shown that it is toxic to living corals.
4. Commensalism is common among all sponges due to their porous nature, which makes them an ideal habitat. A single sponge in Florida was found to have over 16,000 alphaeid shrimps living in it. A study from the Gulf of California found approximately 100 species of plants and animals in a 15 x 15 cm (5.9 x 5.9 in.) section of sponge.
5. There are about 150 species of freshwater sponges.
6. Some sponges are able to regenerate damaged or missing parts.


[[#_ftnref1|[1]]]"The Ecology of Marine Sponge-associated Microorganisms." Department of Microbial Ecology. Faculty of Life Sciences University of Vienna. Web. 28 Apr. 2011.

[[#_ftnref1|[1]]]Taylor, Michael, Peter Schupp, and Peter Steinberg. "Host Specificity in Marine Sponge-associated Bacteria, and Potential Implications for Marine Microbial Diversity." Wiley Online Library. 19 Dec. 2003. Web. 28 Apr. 2011. <http://onlinelibrary.wiley.com/doi/10.1046/j.1462-2920.2003.00545.x/full>

[[#_ftnref1|[1]]]"Nitrogen Fixation in Coral Reef Sponges with Symbiotic Cyanobacteria." Nature Publishing Group : Science Journals, Jobs, and Information. 07 June 1979. Web. 28 Apr. 2011. <http://www.nature.com/nature/journal/v279/n5713/abs/279527a0.html>.

"Animal Life." Animals: Porifera, Cnidaria, Ctenophora. Web. 28 Apr. 2011. <http://users.tamuk.edu/kfjab02/Biology/BIOLOGY%20II/Taxa/b1313_ch18.htm>.

  • Robert W. Thacker
Impacts of Shading on Sponge-Cyanobacteria Symbioses: A Comparison between Host-Specific and Generalist AssociationsIntegr. Comp. Biol. (2005) 45(2): 369-376 doi:10.1093/icb/45.2.369 http://icb.oxfordjournals.org/content/45/2/369.full


"Animal Life." Animals: Porifera, Cnidaria, Ctenophora. Web. 28 Apr. 2011. <http://users.tamuk.edu/kfjab02/Biology/BIOLOGY%20II/Taxa/b1313_ch18.htm>.
Bewley, Holland, and Faulkner. "Two Classes of Metabolites from Theonella Swinhoei Are Localized in Distinct Populations of Bacterial Symbionts." Pubmed.gov. 15 July 1996. Web. 28 Apr. 2011. <http://www.ncbi.nlm.nih.gov/pubmed/8698116>.
"The Ecology of Marine Sponge-associated Microorganisms." Department of Microbial Ecology. Faculty of Life Sciences University of Vienna. Web. 28 Apr. 2011.
Ianni, Sarah. "About Sponges." Tree of Life Web Project. Havergal College, 2005. Web. 28 Apr. 2011. <http://www.tolweb.org/treehouses/?treehouse_id=3431>.
"Nitrogen Fixation in Coral Reef Sponges with Symbiotic Cyanobacteria." Nature Publishing Group : Science Journals, Jobs, and Information. 07 June 1979. Web. 28 Apr. 2011. <http://www.nature.com/nature/journal/v279/n5713/abs/279527a0.html>.
Taylor, Michael, Peter Schupp, and Peter Steinberg. "Host Specificity in Marine Sponge-associated Bacteria, and Potential Implications for Marine Microbial Diversity." Wiley Online Library. 19 Dec. 2003. Web. 28 Apr. 2011. <http://onlinelibrary.wiley.com/doi/10.1046/j.1462-2920.2003.00545.x/full>.
Webster, Nicole, and Linda Blackall. "What Do We Really Know about Sponge-microbial Symbioses[quest]." Nature Publishing Group : Science Journals, Jobs, and Information. ISME Journal, 30 Oct. 2008. Web. 28 Apr. 2011. <http://www.nature.com/ismej/journal/v3/n1/full/ismej2008102a.html>