Geodia conchilega Schmidt (1862) is an irregularly tuberose, orange sponge characteristically covered by attached pieces of shells and stones. Pores lie in sieves overlying incurrent subdermal spaces (chones); oscules similar. It is a Mediterranean species, recorded also from NW Spain.
Colour: Bright orange-yellow, yellowish brown inside; cortex whitish.
Shape, size, surface and consistency: Irregularly tuberose, with pieces of shell or small pebbles attached to the surface. Often agglutinating stones or insinuating in crevices. Size up to 8 cm in diameter. Surface hispid. Pores and oscules arranged in sieves overlying subdermal spaces (chones). Consistency hard.
Spicules: (Geodia conchilega spics) Megascleres: Oxeas, dichotriaenes and anatriaenes. Oxeas rather straight, only slight curved, gradually tapering: 1300-2320 x 20-32 µm. Dichotriaenes, occasionally orthotriaenes, with rather blunt ending rhabd: 1200-3000 x 20-50 µm, protocladi 500 µm, deuterocladi 135 µm; anatriaenes: 2000-4000 x 5-15 µm, cladi 65 µm; protriaenes: 1500-3000 x 5 µm, cladi 100 µm. Microscleres: Sterrasters, strongylasters (chiasters) and oxyasters: sterrasters globular, with a clear hilum, fairly constant in size: ca. 75 x 65 x 60 µm; strongylasters in two size categories: 5-10 µm and 15-30 µm; oxyasters likewise in two categories, small ones with numerous rays: 5-10 µm, and large ones with few rays: 20-30 µm.
Skeleton: There is a thin cortex of 600-3000 µm thick, carried by the cladomes of the dichotriaenes. The anatriaenes and oxeas pass through the cortex and cause the hispidation. The cortex contains a diffuse mass of sterrasters and chiasters. The choanosomal skeleton is pulpy, confused, with radiate skeleton apparent only in the peripheral parts. Riddles with foreign material, sand, shells, diatoms etc.
Ecology: Under stones in the intertidal and shallow water.
Distribution: NW Spain; Mediterranean.
Etymology: conchilega (Latin) = shell collector, referring to the pieces of shell adhering to the surface.
Type specimen information: Three type specimen are incorporated in the Graz Museum, LMJG 15281, 15282 and 15709. No type material in BMNH.
The species stands out among the Geodia species of the area by its encrusted surface and by the lack of small cortical oxeas.
Source: Sollas, 1888; Lendenfeld, 1894.