Table of Contents
Do sponges have bodies?
Many sponges have internal skeletons of spongin and/or spicules of calcium carbonate or silica. Primarily, their body consists of a thin sheet of cells over a frame (skeleton).
What do sponges have instead of bones?
The mesohyl functions as an endoskeleton in most sponges, and is the only skeleton in soft sponges that encrust hard surfaces such as rocks. More commonly the mesohyl is stiffened by mineral spicules, by spongin fibers or both.
What are the body parts of a sponge?
Parts
- archaeocytes (amoebocytes)
- choanocyte – also called collar cells, choanocytes line the inner cavity of the sponge.
- epidermis (pinacocyte)
- flagellum whip-like structure of a choanocyte;
- mesohyl (mesenchyme) the gelatinous layer between the outer body of the sponge and the spongocoel (the inner cavity).
Is a sponge a vertebrate?
Sponges are simple invertebrate animals that live in aquatic habitats. Although the majority of sponges are marine, some species live in freshwater lakes and streams.
What are the 3 sponge body forms?
Sponges have three body types: asconoid, syconoid, and leuconoid. Asconoid sponges are tubular with a central shaft called the spongocoel. The beating of choanocyte flagella forces water into the spongocoel through pores in the body wall. Choanocytes line the spongocoel and filter nutrients out of the water.
What are the six major parts of a sponge?
Structural features
- incurrent pores – ostia (sing. ostium)
- excurrent openings -oscula (sing. osculum) (tree sponge photo)
- spongocoel.
- skeletal elements -protein and spicules (see diagrams in web article)
How are sponges different from all other animals?
The animal nature of sponges, first described in 1755, was confirmed in 1765 after observations of their water currents and the changes in diameter of the openings into their central cavity. In structure, function, and development, sponges are distinct from other animals; one of their most noticeable features is that they lack organs.
Why are sponges described as’asymmetrical’?
Sponges are asymmetrical. They have no front or back, and no right or left side. The choanocytes are specialized cells that use flagella to move a current of water through the sponge, the water leave through to osculum (Shown on the right).
Are there sea sponges that have eyes and ears?
Sea sponges. They’re not exactly the cuddliest of creatures. They don’t have eyes, limbs, ears, a mouth or even a brain.
Where are sponges located in the animal kingdom?
Many zoologists have regarded sponges as occupying an isolated position in the animal kingdom and classify them in the subkingdom Parazoa; however, molecular data suggest that both sponges and more-complex animals evolved from a common ancestor.