Common name: Calcareous Sponges

Calcarea, commonly known as calcareous sponges, are a class of marine sponges characterized by their calcium carbonate spicules. These spicules give the sponges their rigid structure and distinct appearance, often forming intricate and delicate patterns. Calcarea are exclusively marine and are typically found in shallow coastal waters, although some species can be found in deeper ocean environments.

Calcareous sponges are generally small, with some species only reaching a few centimeters in height. They exhibit a variety of shapes, ranging from tubular and vase-like to irregular and encrusting forms. The coloration of these sponges can vary widely, with some displaying vibrant hues while others are more subdued in color.

These sponges play an important ecological role in their environments. They are filter feeders, drawing water in through their porous bodies to extract nutrients and oxygen, which helps maintain water quality and clarity. Additionally, they provide habitat and shelter for a variety of marine organisms, contributing to the biodiversity of their ecosystems.

For reef aquarium enthusiasts, calcareous sponges can be a fascinating addition, though they require specific care conditions. They need stable water parameters, including appropriate calcium levels to support their skeletal structure. Maintaining good water flow is crucial to ensure they receive sufficient nutrients and oxygen. However, they are sensitive to changes in water quality and can be challenging to keep for novice aquarists.

Scientifically, Calcarea are interesting due to their simple body structure and biological significance. They are considered one of the oldest lineages of sponges, providing insights into the early existence of multicellular organisms. Their unique calcium carbonate spicules also make them a subject of interest in studies related to biomineralization processes.

1. 
   Common name: Yellow Calcareous Sponge

   Scientific name: Arthuria canariensis
2. 
   Common name: yellow Clathrina

   Scientific name: Clathrina clathrus
3. Common name: white lace sponge

   Scientific name: Clathrina coriacea
4. Common name: Lemon sponge

   Scientific name: Leucetta chagosensis
5. 
   Common name: Urn Sponge

   Scientific name: Leucilla nuttingi
6. Common name: Johnston's Sponge

   Scientific name: Leuconia johnstoni
7. Common name: White Sponge

   Scientific name: Leuconia nivea
8. 
   Common name: orange pipe sponge

   Scientific name: Leucosolenia botryoides
9. Common name: Leucosolenia complicata

   Scientific name: Leucosolenia complicata
10. Common name: Leucosolenia eleanor

    Scientific name: Leucosolenia eleanor
11. Common name: Heterorhaphis Sponge

    Scientific name: Pericharax heteroraphis
12. 
    Common name: Vase Sponge

    Scientific name: Sycon ciliatum