Prickly tube-sponge

Appearance

The prickly tube-sponge is a large, flexible, brown, sometimes red, tube that can be found as a singular tube or as a cluster. It has been known to reach up to 50 centimeters with specimens as small as 2 mm having been found, but it typically has an average diameter of 30 centimeters. Most of its surface is covered with spines or spine-like protrusions which tend to taper away towards the upper part of the tube.

Naming

The name crassa derives from the Latin word crassus meaning solid, thick, fat, or dense. Its common name, the prickly tube-sponge, comes from its physical appearance as it is a tube sponge and it is nearly completely covered in spines. It was previously named "Sclerochalina crassa," but was eventually moved to the genus "Callyspongia."

The genus "Callyspongia" belongs to the family Callyspongiidae. This family contains four genera: "Arenosclera, Callyspongia, Dactylia," and "Siphonochalina" with "Callyspongia" being the largest and containing over 180 species. They are under the phylum Porifera, making them a sponge. Specifically, they are Demosponges, which is the most diverse class in the phylum Porifera.

Habitat

These sponges are native to the Red Sea. Samples have been found in the southern Red Sea off the coasts of Sudan and Eritrea and in the northern Red Sea in the Gulf of Aqaba at Eilat. They are known to live in marine reef and marine benthic habitats, relatively close to shore. They have been found between a depth of 1–30 m, but they are more abundant at deeper depths. They live in waters with high salinity and warm temperatures, with water in the Red Sea never dropping below 21 °C.

Reproduction

Sea sponges can reproduce both sexually and asexually. They often switch between the two seasonally, to best grow their populations and take up space on the reef.

Food

"Callyspongia crassa" are filter feeders and suspension feeders, but they mainly filter feed. They filter feed because they lack true tissues and organs, so they can not have a digestive system similar to other animals. This sponge filter feeds by taking in water towards the base, filtering it to get the nutrients and food, and then expelling the leftover water out through the osculum. They are omnivores as their diet consists of both small plants and animals.