Ircinia oros is a species belonging to the demospongia that is classified within the Dictyoceratida order and the Irciniidae family. It inhabits both well-lit and poorly lit areas, always associated with rocky bottoms and with the presence of gentle currents. It lives at depths ranging from 15 to 60 meters in the waters of the Mediterranean Sea.
The specimens of Ircinia oros have a spheroid shape that can reach up to 12 cm in diameter and up to 25 cm in height. Its consistency is firm and its color is light brown on the underside, and dark gray at the apices of the large siphonal openings present on its surface. This coloration is variable in intensity depending on exposure to light, ranging from dark brown specimens, to grayish and even totally whitish, although they always maintain the lighter color of the edges of their osculi or exhalant orifices. These siphonal openings have a conical shape and are regularly distributed over the surface. Between these exhalant orifices we find a multitude of small inhalant orifices, through which the specimen introduces the water that surrounds them, in order to capture the organic particles present.
The reproduction of Ircinia oros can be either asexual by gemmation, a method by which colonies of several specimens very close to each other can be formed. Sexual reproduction takes place through the release of sperm into the water column, which if captured by another specimen thanks to the filtration process, will be used to fertilize the eggs. The fertilized eggs develop for a period inside the specimen, and are released already in the form of a planktonic larva.
Ircinia oros can be confused with various sponges species. For example with Spongia offinalis, although this is less spherical, larger, and variable in color from light gray to black. Another species that can lead to confusion is Sarcotragus fasciculatus, also less globular and purple in color.
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