Description: Synonym: Tetilla zetlandica This is a very distinctive spherical sponge, varying in size from a large pea to a golf ball. It is a frequent species in deep water but rarely found in depths which divers can reach. The surface is conulose and there is usually one oscule with a raised rim.

Habitat: Usually below 40 m depth on open coasts and offshore.

Ecology: Often found inside cup shaped sponges, Axinella infundibuliformis and Phakellia ventilabrum.

Distribution: Shetland, Galway, Kerry Head shoals.

Similar Species: Two other spherical species of Craniella are reported from the area, Craniella cranium and Craniella infrequens. The common species Tethya citrina is similar in shape but yellow in colour.

Key Identification Features:

• White ball like sponge.

iNaturalist: Craniella zetlandica at iNaturalist World Species Observations database.

WoRMS: Craniella zetlandica at World Register of Marine Species. Accepted name: Craniella zetlandica (Carter, 1872). AphiaID: 171358.

Classification: Biota; Animalia; Porifera; Demospongiae; Heteroscleromorpha; Tetractinellida; Spirophorina; Tetillidae; Craniella