What is unique about calcarea?

What is unique about calcarea?

Memebers of the group Calcarea are the only sponges that possess spicules composed of calcium carbonate. These spicules do not have hollow axial canals. The Calcarea first appears at the base of the Lower Cambrian and has persisted until the present. Greater than 100 fossil genera are known.

How long do calcareous sponges live?

1 to 16 months
The life span of the species ranged from 1 to 16 months (mean: 4.7 months). Short life spans and variable growth rates have been observed in other species of the class Calcarea.

How many families does Calcarea have?

Number of classes and families: 1 class (Calcarea); 2 subclasses (Calcinea, Calcaronea); 5 orders (2 in Calcinea: Clathrinida, Murrayonida; 3 in Calcaronea: Leucosoleniida, Lithonida, Baeriida); 22 families; 75 genera; about 500 described species.

What is the order of calcarea?

In Calcaronea, three orders are recognized: Leucosolenida, Lithonida, and Baerida. Leucosolenida contains the majority of calcaronean species (9 families, 43 genera, 467 species, Van Soest et al., 2011). Their skeleton is composed of free spicules without calcified non-spicular reinforcements (Borojevic et al., 2000).

How many rays do Calcarea have?

Calcareous spicules, characteristic of the Calcarea, are composed chiefly of calcium carbonate in crystalline forms; e.g., calcite, aragonite. Most calcareous spicules have one axis (monoaxon), which is usually pointed at both ends; these spicules are called oxeas. Triaxons have three rays and are called triacts;…

How do Calcarea reproduce?

Reproduction occurs asexually by budding and sexually. Development of fertilized eggs takes place within the sponge. The larval stage has outer flagellated cells, often with spicules. The young break out of the parent’s mesohyl, and become free swimming larvae, but not for more than two days.

What does a Demosponge eat?

All sponges are filter feeders, subsisting on bacteria and other small organisms. Water bearing these food particles enters through outer pores. Choanocytes capture most of the food; however pinocytes and amoebocytes can also digest food.

How does the calcareous sponge reproduce?

What is the scientific name of Calcarea?

CalcareaCalcareous sponge / Scientific name

What is the osculum in a sponge?

The osculum (plural “oscula”) is an excretory structure in the living sponge, a large opening to the outside through which the current of water exits after passing through the spongocoel. Wastes diffuse into the water and the water is pumped through the osculum carrying away with it the sponge’s wastes.

Where can Demosponge be found?

Class Demospongiae. The Demospongiae is the largest Class in the Sponge Phylum (Porifera), it contains over 90% of living sponges, and nearly all the larger species. They can be found at all depths in both fresh and salt water. The skeleton can be siliceous, spongin, or both.