Hobbies And Interests

Four Types of Sponges

People have used sponges throughout the centuries for a variety of purposes. Known for their strength, softness and versatility, sponges can have one of three types of bodies. Asconoid sponges are shaped like a tube perforated by pores, and the larger syconoid sponges have a tubular body with a simple osculum, or excretory opening. Syconoid sponges have thicker body walls, and and their pores form canals lined by choanoctyes, or collar cells. The third type of body is leuconoid, which belongs to the largest and most complex sponges.
  1. Species

    • About 5,000 species of sponges live in oceans and fresh bodies of water throughout the world. Although they are animals, sponges are mostly stationary after their larval stage. Sponge cells are specialized so that they perform different functions, such as digestion and reproduction. They have a system of pores and canals that take in water. Flagellae, or tiny whips on the collar cells, move the water along. Sponges have skeletons made up of collagen and needle-like spicules, which are made of calcium or silicon. All of this is wrapped in a gelatinous matrix called the mesohyl. Most sponges are filter feeders, and the currents bring their food to them.

    Calcarea

    • Calcarea sponges are the most primitive group of sponges. It's the only class to have asconoid and syconoid body plans. The Calcarea class is divided into two groups, calcinea and calcaronea, which can be distinguished by their larvae. Calcarea sponges reproduce sexually and asexually, by budding. The fertilized eggs develop inside the sponge. The larvae have flagellae, or tails. When they break out of the parent, they become free swimming.

    Hexactinellida

    • Hexactinellida are glass sponges. They're all upright and have structures at their bases that hold them to the ocean floor. They're different from other sponges in that their skeletons are made up of silica. They reproduce sexually. The larvae are incubated inside the sponge for a long time and then released. Unlike other sponge larvae, the larvae of Hexatinellida sponges lack flagellae. Unlike Calcarea sponges, which can move a little bit, Hexactinellida doesn't move at all.

    Demospongiae

    • Demospongiae sponges are variable and can range in size from a few millimeters to more than 2 meters tall. Their bodies can be fingerlike projections, lumps or large urns. They can also be brightly colored. Demospongiae reproduce sexually and asexually. Their larvae have flagellae that help them swim once they're released from the parent.

    Cliona

    • Cliona is a genus in the class Demospongiae. This type of sponge is unusual because it actively eats oysters, other mollusks and coral instead of filter feeding. Cliona will attach itself to an oyster or a clam, very slowly drill holes in it via chemical action, and insert itself through the shell while it devours the animal.


https://www.htfbw.com © Hobbies And Interests