Sponges are a diverse group of sometimes common types, with about 5000 species known across the world. Sponges are primarily marine, but around 150 species live in fresh water. Sponges have cellular-level organization, meaning that that their cells are specialized so that different cells perform different functions, but similar cells are not organized into tissues and bodies are a sort of loose aggregation of different kinds of cells. This is the simplest kind of cellular organization found among parazoans.
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Sponges are a diverse group of sometimes common types, with about 5000 species known across the world. Sponges are primarily marine, but around 150 species.
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Sponges are a diverse group of sometimes common types, with about 5000 species known across the world.
Sponges are primarily marine, but around 150 species live in fresh water.
Sponges have cellular-level organization, meaning that that their cells are specialized so that different cells perform different functions, but similar cells are not organized into tissues and bodies are a sort of loose aggregation of different kinds of cells.
This is the simplest kind of cellular organization found among parazoans.
sponges include a system of pores (also called ostia) and canals, through which water passes.
Water movement is driven by the beating of flagellae, which are located on specialized cells called choanocytes (collar cells).
Sponges are either radially symmetrical or asymmetrical.
They are supported by a skeleton made up of the protein collagen and spicules
Reproduction by sponges is by both sexual and asexual means.
Sponges have three different types of body plans
Asconoid sponges are shaped like a simple tube perforated by pores. The open internal part of the tube is called the spongocoel; it contains the collar cells.
There is a single opening to the outside, the osculum.
Hydra have a saclike body and a circle of tentacles at around the body opening.
HYDRA
This opening is used for both taking in food and eliminating wastes.
Hydra don't have eyes but they can sense light
They will also reproduce easily, either asexually, by forming buds or by laying a single egg.
Hydra are carnivorus and will eat anything they can manage to catch including single celled animals, small crustaceans, worms, insects, and other tiny animals