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.
