Euplectella aspergillum
Euplectella aspergillum, often called the Venus' Flower Basket, is a hexactinellid sponge in the phylum Porifera inhabiting the deep ocean. This sponge was often given as a wedding gift in traditional Asian cultures because it symbiotically houses two shrimp, a female and a male.
E. aspergillum has glassy fibers five to twenty centimeters long and thin as human hair that attach it to the ocean floor. It extracts silica acid from seawater and converts it into silica, then forms it into an elaborate skeleton of glass fibers. This process is very intricate and is of high interest to fiber optics researches.
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 6-pointed siliceous spicules, which is why they are commonly known as glass sponges. The spicules are composed of 3 perpendicular rays giving them 6 points. Spicules are microscopic, pin-like structures within the sponge’s tissues that provide structural support for the sponge. It is the combination of spicule forms within a sponge’s tissues that helps identify the species.
E. aspergillum has glassy fibers five to twenty centimeters long and thin as human hair that attach it to the ocean floor. It extracts silica acid from seawater and converts it into silica, then forms it into an elaborate skeleton of glass fibers. This process is very intricate and is of high interest to fiber optics researches.
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 6-pointed siliceous spicules, which is why they are commonly known as glass sponges. The spicules are composed of 3 perpendicular rays giving them 6 points. Spicules are microscopic, pin-like structures within the sponge’s tissues that provide structural support for the sponge. It is the combination of spicule forms within a sponge’s tissues that helps identify the species.
Characteristics of a Nervous System in E. aspergillum
Although E. aspergillum does not have a nervous system, the activities that it involves itself in do lend themselves to the characteristics of a nervous system. In the case of glass sponges the 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. This is one example of the sponge responding to its environment and performing actions that correspond to those of a nervous system. The top end of the sponge has a sieve-like disc over the end and the sponge is anchored to the substrate by means of fine, hair-like fibres. These fibres are between 50 and 175mm long. Recent research has proved that these fibres have the same composition as fibre-optical cables like those used in modern telecommunications. They can trap and transmit light. It is believed that sponges do this to attract symbiotic algae or as an attractant for the shrimp which live within the sponge’s body cavity. Either way this is another example of the sponge controlling its activity as a result of the environment that it is in. Whether the growth of these fibers is voluntary or not, the sponge still shows signs of being self-aware, responsive, and sensitive, all of which are characteristic of a nervous system.
Adult sponges do lack neurons or any kind of nervous tissue, yet they still have the ability to execute movements that are coordinated all over their bodies. They do this by squeezing the water channels and expelling excess sediment as well as any other substances that can cause blockages. This in itself shows that sponges like E. aspergillum do perform movements that are similar to those carried out by nervous systems. In fact, sponges contain genes very similar to those that contain the instruction for the post-synaptic destiny, which is a vital signal-recieving structure in the neurons of all other animals. However in sponges these genes are only activated in "flask cells" that appear only in larvae and may provide some sensory capability while the larvae are swimming. This raises questions about whether flask cells represent the predecessors of true neurons or are evidence that sponges' ancestors had true neurons but lost them as they adapted to a sessile lifestyle
Adult sponges do lack neurons or any kind of nervous tissue, yet they still have the ability to execute movements that are coordinated all over their bodies. They do this by squeezing the water channels and expelling excess sediment as well as any other substances that can cause blockages. This in itself shows that sponges like E. aspergillum do perform movements that are similar to those carried out by nervous systems. In fact, sponges contain genes very similar to those that contain the instruction for the post-synaptic destiny, which is a vital signal-recieving structure in the neurons of all other animals. However in sponges these genes are only activated in "flask cells" that appear only in larvae and may provide some sensory capability while the larvae are swimming. This raises questions about whether flask cells represent the predecessors of true neurons or are evidence that sponges' ancestors had true neurons but lost them as they adapted to a sessile lifestyle