Euplectella aspergillum

Last updated:

Geographic Range

This sponge species is found in the western Pacific Ocean near the Philippine Islands. Other species in this genus are found in oceans all around the world (Bayer and Owre 1968; Pearse and Buchsbaum 1987; Britannica.com 1999-2000).

Habitat

This species is found attached to rocky areas of the seafloor. It is found from 100 to 1000 m below the surface, and is most common at depths greater than 500 m (Bayer and Owre, 1968; Coleman 1991; Pearse and Buchsbaum, 1987).

Physical Description

E. aspergillum is radially symmetric and of moderate size, ranging from 7.5cm up to 1.3m in height. The majority are between 10cm and 30cm tall. The 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. Surrounding this beautiful skeleton is a net of living tissue called a trabecular net, which is created by the fusion of amoeboid cells called archaeocytes. Within this trabecular net are elongated, finger-like chambers covered in choanocytes, which open into the spongocoel. Choanocytes are another class of cells, they have whip-like flagella that they vibrate in order to move water through the sponge. Both the external and internal surfaces are covered by this trabecular net. The chambers throughout the body are irregular. The end result is a funnel or vase-like shape. Hence the name, 'Venus's-Flower-Basket.' At its base, E. aspergillum has a tuft of elongated spicules that attaches it to the ocean bottom (Buchsbaum and Pearse, 1987; Hickman, Roberts, and Larson 1997; Kaestner 1967).

Reproduction

"Little is known about their reproduction". Details of reproduction of E. aspergillum are not known, therefore we can only explain the normal forms of reproduction in Porifera in general. Many times when unfavorable conditions occur sponges will resort to asexual reproduction. In marine sponges using asexual reproduction, amoebocytes attach themselves around the deteriorating sponge. Later epithelial cells surround the amoebocytes, and when the deteriorating sponge is all gone a new animal grows from the clump of cells. Some sponges have two sexes, and individuals have only one sex, but it is likely that E. aspergillum is hermaphroditic, producing both male and female gametes at different times. Archaeocytes and choanocytes have both been observed maturing into gametes, and these maturations are similar to those found in higher animals. Sperm enter the sponge through the inhalant current and then fertilize the ova. A carrier cell, an amoebocyte, effects fertilization of the ovum so that not just sperm and ova are involved. Then the carrier cell and the sperm both reach the ovum, and form a cytostome, which engulfs both the carrier cell and sperm. This zygote then goes through radial holoblastic cleavage forming cells all similar in size and shape. Then the embryo forms a free-swimming larva, which eventually develops into the new sponge. (Bayer and Owre, 1968; Kaestner, 1967)

Behavior

Because E. aspergillum is found at such great depths the information about its active life is limited. This is a sessile animal that protrudes from the rocky ocean bottoms also making it a benthic (bottom dweller) animal (Buchsbaum and Pearse 1987; Hickman, Roberts, and Larson 1997; Kaestner 1967).

Food Habits

E. aspergillum's staple food is microscopic organisms and organic debris. These are filtered out of the water that flows through the sponge. (Britannica.com, 1999-2000).

Economic Importance for Humans: Positive

No positive benefits recorded.

Economic Importance for Humans: Negative

No adverse affects recorded.

Conservation Status

Through researching this invertebrate animal, and not finding a great deal of information I have come to the conclusion that since E. aspergillum is found at such great depths, the status of its population is not known.

Other Comments

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" (Jensen,1979).

Contributors

Beau McKenzie Soares (author), Fresno City College, Jerry Kirkhart (editor), Fresno City College.

Glossary

Pacific Ocean

body of water between the southern ocean (above 60 degrees south latitude), Australia, Asia, and the western hemisphere. This is the world's largest ocean, covering about 28% of the world's surface.

World Map

benthic

Referring to an animal that lives on or near the bottom of a body of water. Also an aquatic biome consisting of the ocean bottom below the pelagic and coastal zones. Bottom habitats in the very deepest oceans (below 9000 m) are sometimes referred to as the abyssal zone. see also oceanic vent.

coastal

the nearshore aquatic habitats near a coast, or shoreline.

native range

the area in which the animal is naturally found, the region in which it is endemic.

sessile

non-motile; permanently attached at the base.

Attached to substratum and moving little or not at all. Synapomorphy of the Anthozoa

References

Bayer, F., H. Owre. 1968. The Free-Living Lower Invertebrates. New York: The Macmillan Company.

Britannica.com, 1999-2000. "Venus's Flower Basket" (On-line). Accessed October 27, 2000 at http://www.britannica.com/seo/v/venuss-flower-basket/.

Buchsbaum, R., M. Buchsbaum, J. Pearse, V. Pearse. 1987. Animals Without Backbones. Chicago and London: University of Chicago Press.

Coleman, N. 1991. Encyclopedia of Marine Animals. Australia: Angus & Robertson.

Hickman, C., L. Roberts, A. Larson. 1997. Integrated Principles of Zoology. New York: The McGraw-Hill Companies, Inc..

Jensen, A. 1979. Wildlife of the Oceans. New York: Chanticleer Press, Inc..

Kaestner, A. 1967. Invertebrate Zoology. New York: A Division of John Wiley & Sons.

Pearse, V., J. Pearse, M. Buchsbaum, R. Buchsbaum. 1987. Living Invertebrates. Pacific Grove, California: The Boxwood Press.