A bright yellow sponge, first described in 2007, that grows on limestone.

In brief

• This sponge is a distinctive bright yellow colour.
• It is only found at a few sites in Britain and Ireland.
• In Northern Ireland it can be found at some sites around Rathlin Island.
• Grows on limestone.
• Northern Ireland is a stronghold for this species.

Species description: This massive sponge is a distinctive bright yellow colour, with a habit of bridging crevices and may burrow into the rock. The surface is smooth and slightly glossy and there are conspicuous circular oscules with slightly raised rims.

Life cycle: Unknown.

Similar species: Cliona celata is similar in colour but always has well-defined inhalent pore sieves.

How to see this species: Found on limestone rocks at Rathlin Island and several sites on the west coast of Ireland at depths of 20-40 m. Usually out of the light, beneath overhangs or in caves. Currently only known from select sites on the West and North coasts of Ireland. Aside from the island of Ireland there are only 3 other records from this region, all from Wales.

Current status: Rare. Northern Ireland, specifically Rathlin Island, is a currently regarded as as stronghold for this species.

Why is this species a priority in Northern Ireland?

• Criterion 3: Rare or restricted range – rare breeding species confined to 5 hectads or less (based on expert judgement).
• Criterion 4: NI stronghold or endemic – both stronghold range/population and designation as ‘endemic’ subject to expert judgement.

Threats: No specific threats known, but vulnerable to habitat degradation or loss of water quality due to only being found in a few specific sites.

Action: Records of new sites for this species, with details of habitat and population are always valuable. Observations with a photograph can be recorded using iNaturalist, find the MBDP-NI iNaturalist project here.

Alternatively, records can be sent to CEDaR, National Museums Northern Ireland, 153 Bangor Road, Cultra, Holywood, County Down, BT18 0EU. Tel 028 9039 5257, e-mail cedar.records@nationalmuseumsni.org, or via the online portal.

Objectives:

• Maintain the number and size of viable populations.
• Maintain the range of this species.
• Monitor the populations at key sites.

Conservation:

• Rathlin Island is a Marine Protected Area with multiple designations.
• There is Habitat Action Plan for Fragile Sponge and Anthozoan Communities on Rocky Habitats.
• The Maidens are a Marine Protected Area with multiple designations.

Distribution Map from NBN: Spongosorites calcicola at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Spongosorites calcicola at iNaturalist World Species Observations database.

WoRMS: Spongosorites calcicola at World Register of Marine Species. Accepted name: Spongosorites calcicola Picton & Goodwin, 2007. AphiaID: 255161.

Classification: Biota; Animalia; Porifera; Demospongiae; Heteroscleromorpha; Suberitida; Halichondriidae; Spongosorites

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Picton, B.E., Keatley, L. & Morrow, C.C. (2026). Spongosorites calcicola. Picton & Goodwin, 2007. [In] Priority species, Marine Biodiversity Portal NI. https://www2.habitas.org.uk/marbiop-ni/priorityaccounts.php?item=C5070. Accessed on 2026-09-13