Lobed Oscarella Sponge
The lobed Oscarella sponge (Oscarella lobularis) is a soft, crust-like sponge of the Mediterranean that comes in several colors, including blue, yellow and brown.
The lobed Oscarella sponge (Oscarella lobularis) is a soft, crust-like sponge of the Mediterranean that comes in several colors, including blue, yellow and brown. It belongs to the homoscleromorphs, sponges with a surprising amount in common with other animals.
🧬 Field Guide Specimen: Open Lobed Oscarella Sponge in the CRV Science Field Guide to log the specimen, see its place among the Metazoa lineages in the Cladogram Explorer, and test your recall in the Red List conservation game.
Sponges With Real Epithelia: Why Does That Matter?
Homoscleromorph sponges have a layer of cells joined by junctions and resting on a basement membrane, similar to the epithelia of other animals. This discovery bears on the question of whether animal tissues arose once, early in evolution, or more than once.
No Skeleton at All
Oscarella lacks spicules, leaving it with a flexible, mucus-covered body that spreads over rocks in shaded caves and crevices. It can change shape continuously by remodeling its tissue.
A Model for Early Animals
Genome and developmental studies of Oscarella are used to reconstruct the toolkit of genes present in the first animals. The relations of sponge groups to each other and to other animals remain debated.
Lobed Oscarella Sponge at a Glance
| Property | Value |
|---|---|
| Scientific name | Oscarella lobularis |
| Kingdom | Animalia |
| Phylum | Porifera |
| Class | Homoscleromorpha |
| Order | Homosclerophorida |
| Family | Oscarellidae |
| Field Guide group | Porifera: Sponges (Basal Metazoans) |
| Diagnostic feature (Field Guide) | Smooth, velvety, lobed encrusting sheet completely devoid of both mineral spicules and spongin fibers; possesses true basal membrane with collagen IV. |
| Class | Homoscleromorpha |
| Spicules | None |