What is the function of spongin?
Spongin, a modified type of collagen protein, forms the fibrous skeleton of most organisms among the phylum Porifera, the sponges. It is secreted by sponge cells known as spongocytes. Spongin gives a sponge its flexibility. True spongin is found only in members of the class Demospongiae.
What are the functions of the spicules and spongin skeleton?
The mineral skeleton is formed for the most part by units called spicules, either scattered throughout the sponge or united to form fibres; spicules are classified as megascleres, which function in support, and microscleres, which function in protection and also aid in support.
What is the function of Amoebocytes in sponges?
Amoebocytes have a variety of functions: delivering nutrients from choanocytes to other cells within the sponge; giving rise to eggs for sexual reproduction (which remain in the mesohyl); delivering phagocytized sperm from choanocytes to eggs; and differentiating into more-specific cell types.
What is spicules and spongin?
Skeletal structures of sponges are spicules and spongin fibres. Spicules are formed by carbonates of lime or silica in the form of needle like pieces. Spongin fibres are composed of a silk-like scleroprotein.
Why are spongin and spicules important to the sponge?
Spongin and spicules provide support and support the soft body parts of the sponges. The spicules give the sponges rigidity and form to the sponges.
What is the difference between Spongin and spicules?
Spongin is a modified type of collagen protein, and forms the “fibers” or “mortar” that hold spicules together. Spicules are the structural components of a sponge, or the “bricks,” and the shapes, sizes, and composition are unique for each species.
Why are Spongin and spicules important to a sponge?
Why are amoebocytes important?
Amoebocytes have a variety of functions: delivering nutrients from choanocytes to other cells within the sponge, giving rise to eggs for sexual reproduction (which remain in the mesohyl), delivering phagocytized sperm from choanocytes to eggs, and differentiating into more-specific cell types.
What are amoebocytes responsible for?
Amoebocytes are motile cells that can transform themselves into any other cell. They play a vital role in structure, digestion, reproduction, and regeneration. This lesson will explain the various roles these amoeba like cells play in sponges.
What are spongin fibers?
Spongin fibers are fine threads consisting of a soft granular axial core externally surrounded by concentric layers of spongin. Spongin contains large amounts of iodine.
What does the amebocyte do?
saɪt/) is a mobile cell (moving like an amoeba) in the body of invertebrates including echinoderms, molluscs, tunicates, sponges and some chelicerates. Depending on the species, an amebocyte may also digest and distribute food, dispose of wastes, form skeletal fibers, fight infections, and change into other cell types.
What does the skeleton of a sponge do?
Skeleton supports and protects the soft body parts of the sponges. Skeleton also serves as the basis of classification of the sponges into various classes like Calcarea, Hexactanellida and Desmospongia. Spongin is an organic, horny, elastic substance which resembles silk in chemical composition.
How are spongin fibers secreted in a sponge?
Spongin fibers are secreted by flask-shaped mesenchyme cells called as spongioblast cells. During the development the spongioblast cells are arranged in the rows and the spongin rods secreted by them are fused with the neighboring cells to form a long fiber.
Why are spicules important in the phylogeny of sponges?
The genetic control of spicule shapes makes them useful in the reconstruction of sponge phylogeny, although recent experiments have demonstrated the influence of environmental factors in modulating spicule size, shape, and the presence or absence of one or more spicule types. The implications of such variations in sponge taxonomy may be important.
How does silica deposition take place in a sponge?
Silica deposition is a fundamental process in sponges. Most sponges in the Classes Demospongiae and Hexactinellida secrete siliceous elements, which can subsequently fuse, interlock with each other, or form three-dimensional structures connected by spongin.