What is the most common class of sponges?
class Desmospongia
The skeletons of the class Desmospongia are composed of spicules made up of silica and skeletal fibers made from spongin, a type of collagen protein. Desmospongia is the most abundant class of sponges alive today. More than 90% of all known sponge species are found within the class desmospongia.
Is Hexactinellida a class?
Hexactinellida are characterized by having siliceous hexactine (six-pointed) spicules, making them the second class within the major sponge group Silicea. They also construct two different body plans: sycon and leucon.
What is the common name of phylum Porifera?
sponges
Phylum Porifera (“pori” = pores, “fera” = bearers) are popularly known as sponges.
What are the classes of sponges?
Sponges are classified within four classes: calcareous sponges (Calcarea), glass sponges (Hexactinellida), demosponges (Demospongiae), and the recently-recognized, encrusting sponges (Homoscleromorpha).
What is the meaning of Hexactinellida?
Hexactinellids (glass sponges) are deepwater marine sponges that have skeletons of siliceous (glass) spicules with a distinctive triaxonic (cubic three-rayed) symmetry. Unlike the other two main classes of sponges (Calcarea and Demospongiae), glass sponges lack either a calcareous or organic skeleton.
What is the phylum of a jellyfish?
Phylum Cnidaria
Corals and Jellyfish: Phylum Cnidaria.
Which one is the example of class Demospongia?
Included are the yellow tube sponge, Aplysina fistularis, the purple vase sponge, Niphates digitalis, the red encrusting sponge, Spiratrella coccinea, and the gray rope sponge, Callyspongia sp.
What is Hexactinellida scientific name?
HexactinellidaGlass sponges / Scientific name
What are the 3 main classes of Porifera sponges )?
The approximately 5,000 living sponge species are classified in the phylum Porifera, which is composed of three distinct groups, the Hexactinellida (glass sponges), the Demospongia, and the Calcarea (calcareous sponges).
What are the two types of hexactinellids?
Within each of the two subclasses of hexactinellids are sponges with loose skeletons-spicules held together by living tissue-and sponges with fused skeletons. Sponges of both designs are essentially vase-shaped, with a large central or atrial cavity, usually with one opening, the osculum.
What is the range of a hexactinellid?
Hexactinellid sponges are known at depths from 30 to 22,200 ft (9.14–6,770 m) in all oceans. There are no records of this class in freshwater. The fossil record suggests that their historical range was similar. The vast majority of hexactinellids live at depths greater than 1,000 ft (304.8 m).
When did Hexactinellida first appear?
The Precambrian fossil record of Hexactinellida is relatively sparse, but the group began to flourish in the Cambrian (541-485 Ma) and radiated into a number of taxa with diverse skeletal designs, most of which did not survive into the Mesozoic (252-66 Ma).
Are there any Hexactinellids not listed by the IUCN?
Not listed by the IUCN. This is the most intensely studied hexactinellid, because of its occurrence within scuba range on the coast of British Columbia, Canada, and its high rate of survival in the laboratory. Reiswig, Henry M. “Class Hexactinellida Schmidt, 1870.”