''Agelas flabelliformis'', also known as the elephant ear sponge, is a species of

demosponge Demosponges or common sponges are sponges of the class Demospongiae (from + ), the most diverse group in the phylum Porifera which include greater than 90% of all extant sponges with nearly 8,800 species A species () is often de ...

. It takes the form of a large leathery slender flap and is found in the Caribbean area at depths down to .

Description

The elephant ear sponge consists of a large thin flap of spongy material attached edgewise to the

substrate Substrate may refer to: Physical layers *Substrate (biology), the natural environment in which an organism lives, or the surface or medium on which an organism grows or is attached ** Substrate (aquatic environment), the earthy material that exi ...

by a short peduncle or stem about in diameter. It is usually less than thick but may reach a height and width of a metre (yard) or so. There is often a central lobe with two side flaps. The consistency is firm and leathery but also fragile. On one side it has many large, circular osculi (holes) scattered across the surface. On the other side are small pores and a few, widely dispersed, irregular osculi and some groups of smaller ones. Each vent is surrounded by a collar or rim of thickened skin. The tissue forming the sponge is strengthened by the incorporation of a single type of mineralised

spicule Spicules are any of various small needle-like anatomical structures occurring in organisms Spicule may also refer to: *Spicule (sponge), small skeletal elements of sea sponges *Spicule (nematode), reproductive structures found in male nematodes ( ...

. These spicules are classified as acanthostyles and consist of curved rods, with one end pointed and with whorls of spines on the shaft. The spicules are embedded in the sponge's tissues where they form a mesh-like, interlocking skeleton. The colour of this sponge is yellowish-brown, fawn or dark brown, sometimes with pale edges and it is said to resemble a piece of tanned cow-hide. It is similar in appearance to '' Agelas dispar'' but can be distinguished from that species by the size and shape of the spicules in its skeleton.

Distribution

The elephant ear sponge grows on rocks in the eastern Caribbean Sea and the Bahamas. The depth range is normally but it is found at shallower depths in caves.

Biology

Like other sponges, the elephant ear sponge feeds by drawing water in through its pores,

filtering Filtration is a physical process that separates solid matter and fluid from a mixture. Filter, filtering, filters or filtration may also refer to: Science and technology Computing * Filter (higher-order function), in functional programming * Fil ...

out the

bacteria Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, prokaryotic microorganisms. Typically a few micr ...

and other fine organic particles and expelling the water through the osculi. Sponges are unable to defend themselves physically from

predators Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill ...

but many have developed chemicals that make them distasteful to fish. The tissues of this sponge contain several

secondary metabolite Secondary metabolites, also called ''specialised metabolites'', ''secondary products'', or ''natural products'', are organic compounds produced by any lifeform, e.g. bacteria, archaea, fungi, animals, or plants, which are not directly involved ...

s, two of which have been shown to have

immunosuppressive Immunosuppression is a reduction of the activation or efficacy of the immune system. Some portions of the immune system itself have immunosuppressive effects on other parts of the immune system, and immunosuppression may occur as an adverse react ...

properties.

References

{{Taxonbar, from=Q3516975 Agelasida Animals described in 1883