Tethyida

Tethyida is an order of demosponges within the class Demospongiae. They are characterized by their spherical or ovoid shape and often have a dense cortex and a fibrous or granular interior. Tethyida sponges are found in marine environments worldwide, typically in shallow waters, often attached to rocky substrates or other hard surfaces.

Characteristics:

• Shape: Primarily spherical or ovoid, but can exhibit variations.
• Cortex: Usually a distinct and dense outer layer.
• Interior: Typically fibrous or granular.
• Skeleton: Possess a siliceous skeleton made up of spicules, often with distinct types of spicules arranged in specific patterns. Megascleres are common.
• Habitat: Predominantly marine, found in a range of depths but most frequently in shallower waters.
• Distribution: Globally distributed.
• Reproduction: Reproduce sexually and asexually.

Taxonomy:

Tethyida is a well-established order within the Demospongiae. The classification within the order has been subject to revisions based on morphological and molecular data. Important families within Tethyida often include Tethyidae.

Ecological Significance:

Tethyida sponges play a role in marine ecosystems, contributing to biofiltration and providing habitat for other organisms. They are an important component of benthic communities.

Fossil Record:

The fossil record of Tethyida sponges extends back to the Mesozoic era. Fossilized spicules and skeletal remains provide evidence of their evolutionary history and distribution.