Sponges Lecture Review

Flashcards covering the characteristics, feeding, support, diversity, response, reproduction, and ecological importance of sponges based on the lecture notes.

In which phylum are sponges classified?

Phylum Porifera

What are some fundamental characteristics of sponges regarding their internal organization?

Sponges have no tissues, no organs, and most lack symmetry.

What unique ability do sponges possess if broken down into individual cells?

Individual cells will reform a new sponge.

Describe the basic body structure of a sponge.

Sponges are composed of two layers of independent cells with a jellylike substance in-between.

What is the mouth-like opening at the top of a sponge called?

An osculum

How do sponges obtain food?

They are filter feeders that obtain food by filtering small particles out of the water.

What is the lifestyle of adult sponges?

They are sessile, meaning attached and staying in one place.

Where does digestion of nutrients take place in a sponge?

Within individual cells.

What are archaeocytes and what are their functions?

Archaeocytes are amoeba-like cells that secrete spicules (support structures) and are involved in digestion, egg and sperm production, and excretion.

What are spicules?

The support structures of sponges, secreted by archaeocytes.

Upon what are sponges classified into three classes?

The type of support system they have.

Which class of sponges has spicules composed of spongin fiber, silica, or both?

Demospongiae

Which class of sponges has spicules composed of calcium carbonate?

Calcarea

Which class of sponges has spicules of silica joined together to form a netlike skeleton, often with 6 rays?

Hexactinellida

Do sponges possess a nervous system?

No, sponges do not have nervous systems.

How do sponges detect and respond to external stimuli?

They have epithelial-like cells that detect stimuli like touch or chemical signals and respond by closing their pores.

List some methods of asexual reproduction in sponges.

Fragmentation, budding, and gemmules (sponge cells protected by spicules).

Describe the process of sexual reproduction in most sponges.

Eggs remain within the sponge, sperm are released into the water. After fertilization, the zygote develops into a free-swimming larva.

What is the ecological importance of sponges as a food source?

Sponges are food for some tropical fishes and turtles.

How do sponges contribute to marine habitats?

They form habitats for a variety of worms, fishes, shrimp, and symbiotic green algae.

Name two ways sponges are beneficial to humans.

Spongin fiber sponges are used for household scrubbing purposes, and they have potential use in pharmaceutical products.