Antho brattegardi is a yellow encrusting sponge which is a member of the Rathlin Island circalittoral sponge communities. It has been found at several sites around the Irish Sea, in Pembrokeshire and SW Scotland. Elsewhere it is only known from a Norwegian fjord and from a deep-water coral reef near Mingulay, Scotland.

In brief

• Found on Rathlin Island and the Maidens, off Larne
• Lives on steep or vertical rockfaces in water of 25m or greater depth in moderate to strong tidal streams
• Not seasonal, this sponge probably remains in one place for many years
• Northern Ireland is a stronghold for this species
• Requires rock or Lophelia reef habitats in clean water with a minimum of turbidity

Species description: This sponge grows as encrusting patches from 2cm to 5cm in diameter and typically 2mm in thickness. The surface has a porous appearance and oscules with slightly raised transparent rims. The oscules are spaced typically 2cm apart and a surface network of transparent channels leads to each oscule. All individuals so far identified have been yellow in colour, whilst most Antho species are red or orange.

Life cycle: Reproduction is by swimming larvae which must find suitable substratum to settle on. Settlement in suitable water conditions and initial growth are probably when most mortality occurs due both to chance and to competition for space.

Similar species: There are a number of yellow encrusting sponges in our area and this species is not identifiable with certainty in situ.

How to see this species: Found on steep rockfaces in the circalittoral zone usually in places where there are many other encrusting sponges. Its bright yellow coloration makes this species conspicuous but it has no clear features which can be used to identify it in situ and requires microscopic examination of its spicules for confirmation.

Current status: This species has been found regularly at Rathlin Island and the Maidens, off Larne. There is a single record of a substantial patch from the wreck of the "Chirripo" at the entrance to Belfast Lough. All records are from 2005 onwards. Elsewhere it has been found in SW Scotland and Pembrokeshire, Wales. In deeper water it has been found on a Lophelia reef near Mingulay in the outer Hebrides, but not at reefs in deeper water on the edge of the continental shelf which have been surveyed using the same techniques.

Why is this species a priority in Northern Ireland?

• Rare - confined to a small population of one or two sites in Northern Ireland with Northern Ireland being a stronghold (S) consisting of either:

• >50% Irish population or
• >20% UK population/range
• At least 20% of international population of species or well-recognised subspecies occurring in Northern Ireland

Threats: The main threat to this species is degradation of water quality due to increased turbidity, pollution or nutrient enrichment. Inorganic silt clogs sponges making them unable to filter feed and such silt is artificially suspended into the water column by bottom-fishing activities. Some species of sponge can actively clean their surfaces to some extent and may become competitively able to displace other species if there is a shift in water quality. Polluted water may cause sponges to become diseased and may benefit some species at the expense of others by providing more bacteria and less plankton as food. Nutrient enrichment may have similar effects by changing the amounts of different types of plankton on which the sponges feed.

Action:

• Maintain the number of viable populations of the species
• Maintain the range of the species
• Establish appropriate management on appropriate historic sites

Objectives: Encourage sustainable use of the seas by avoiding consumption of fish and shellfish captured by bottom dredging and bottom trawling.

Conservation:

• Rathlin Island is a marine Special Area of Conservation
• The Maidens are a candidate SAC
• Discovered on Rathlin Island by the Rathlin Island sponge project in 2005

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

iNaturalist: Antho brattegardi at iNaturalist World Species Observations database.

WoRMS: Antho brattegardi at World Register of Marine Species. Accepted name: Antho (Jia) brattegardi van Soest & Stone, 1986. AphiaID: 827727.

Literature:

Picton, B.E. and Goodwin, C.E. (2007). Sponges of Rathlin Island. Journal of the Marine Biological Association of the United Kingdom 87(6): 1441-1458.
Roberts, J.M., Davies, A.J., Henry, L.A., Dodds, .LA. et. Al. (2009). Mingulay reef complex: an interdisciplinary study of cold-water coral habitat, hydrography and biodiversity. Mar Ecol Prog Ser 397: 139-1511.

Classification: Biota; Animalia; Porifera; Demospongiae; Heteroscleromorpha; Poecilosclerida; Microcionidae; Ophlitaspongiinae; Antho

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Bernard Picton (2026). Antho brattegardi. van Soest & Stone, 1986. [In] Priority species, Marine Biodiversity Portal NI. https://www2.habitas.org.uk/marbiop-ni/priorityaccounts.php?item=C8330. Accessed on 2026-07-28