Question

1. Describe the general organization, feeding mode and life cycle of a sponge. Be sure to include the following terms:  spicule, choanocyte, spongocoel, osculum, mesohyl, amoebocytes. Are sponges able to move?  If so, how and why?

Answer 1

Introduction;

The sponges are marine living majorly. The larvae of the sponges able to swin, whereas the adults can't move(sessile) stick to one place. These sponges are classified as four calsses calcareous sponges, glass sponges, desmosponges and encrusting sponges.

The differentiation between the diffey types of sponges takes place by the prsey and composition of the spicules and spongin.

Desmosponges have spongin but not spicules. The calcareous sponges have calcium spicules. Hemoscleromorpa sponges have small spicules. Hexactinellid sponges have silica spicules.

General chacteristics:

Sponges doesn't have organs, tissues and body symmetry. The body volume is build up by the water accumulated in the body ( through the central cavity). The nutrients are deposited in the central cavity and leaves through the osculum. Sponges have internal spicules made of calcium or silca.

Water is essential for the sponges to perform feeding, gas exchany and excretion.

Sponges are cylinder in shape with central large cavity called spongocoel. The water enter into spongocoel through the pores and exit through osculum.sponges exhibit diversity.

Choanocytes are also called collar cellls are located in various locations depending on the type of sponge. The collar cells located on the inner portion of some space through which the water enters. Pinocytosis lie outside of the sponges.

The cell body is embedy with mesohyl. The food particles are trapped by the collar cells and enter into the body. The collar cells perform vital function in reproduction. Chonacytes will form into sperm for the sexual reproduction.

Amoebocytes are other important cells in sponge.

The sponges are sessile and they deed on the phagocytosis process.

Life cycle

The reproduction done by both sexual and asexual methods. Asexual reproduction is by budding. The sexual reproduction is by mesohyl. The male gametes are released into water get trapped by the collor cell means the spermatozoa trapped by the collor cells.

The sperm carried to egg and fertilization occurs and the blastula is relased into water. The released blastula settle and form into adult sponge.

Locomotion:

Sponges don't move fast hence, thay are considered as slow moving animals. Most of the sponges move less than a millimeter vin a day. Most of the sponges are termed as sessile, which means they stick to one place and dont move at all. They pump large amount of water into the bodies and filter the tiny and organic organisms and consume them as food.