This is a small rare red seaweed or alga discovered and named in 1985 for the first time in the world. It has no common name.

In brief

• Small red marine algae found at seven sites in Northern Ireland: Rathlin Island, Murlough Bay, Torr Head, Loughan Bay and Ringfad Point in County Antrim and on Lighthouse Island and near Rue Point in County Down
• Known only from below low water (the sublittoral) to a depth of 15m on cobbles and pebbles
• It is scarce with Northern Ireland being an Irish stronghold for this species
• The only threat is to its habitat
• The most obvious stage of its life cycle is of a plant which is soft and mucilaginous growing in tufts, mature plants up to 8cm long. The other stages are small or microscopic.

Species description: This alga has three stages (or phases) in its life cycle; each is different in appearance. The upright stage is soft, gelatinous and no more than 8cm long, 6cm wide and a few millimetres thick. It is flattened and divided in a leaf-like manner with marginal proliferations. Rose pink in colour. Under the microscope the blades can be seen to be composed of a filamentous axis bearing whorls branchlets. These whorls branchlets branch to form a cortex.

The second stage is microscopic and concerned with the fertilization and release of spores. The third stage (or phase) grows in a crust-like manner, is of firm texture, small, only 6mm in diameter and is bright red in colour. It also releases spores. The second and third stages are very small, one is microscopic.

Life cycle: The life cycle of the red algae is complex. The upright (gametophyte) stage of this species has male and female sex cells. After fertilization the second stage (or phase), which is microscopic, develops (the carposporophyte), it remains attached to the female plant and when mature it produces spores (carpospores). These spores, when released, grow and develop to form a crust-like alga quite different in appearance from the other stages and closely attached to a substrate. This crust-like stage (the tetrasporophyte) produces spores in fours which, when released, settle and grow to form the upright (gametophyte) stage, thus completing the cycle.

Similar species: This species is a flattened plant quite distinct from other species of Schmitzia.

How to see this species: Schmitzia hiscockiana has been recorded from seven sites in Northern Ireland: Rathlin Island, Murlough Bay, Torr Head, Loughan Bay and Ringfad Point in County Antrim and Lighthouse Island and near Rue Point in County Down. It occurs only where there is strong wave action or tides at depths of 4-17m on cobbles and pebbles. It is best searched for by scuba-diving.

Current status: Schmitzia hiscockiana has been found at seven sites in Northern Ireland, in County Antrim and County Down.

Why is this species a priority in Northern Ireland?

• Scarce with Northern Ireland being an Irish stronghold for this species.

Threats: The only threat is to its habitat.

Action:

• The status of Schmitzia hiscockianawill be surveyed and monitored and appropriate conservation action undertaken if required.

What

Objectives: No relevant action.

Conservation:

• Rathlin Island is designated as a SAC.

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

iNaturalist: Schmitzia hiscockiana at iNaturalist World Species Observations database.

WoRMS: Schmitzia hiscockiana at World Register of Marine Species. Accepted name: Schmitzia hiscockiana Maggs & Guiry, 1985. AphiaID: 145603.

Literature:

Maggs, C.A. and Guiry, M.D. (1985). Life history and reproduction of Schmitzia hiscockiana sp. nov. (Rhodophyta, Gigartinales) from the British Isles. Phycologia 24: 297–310.

Morton, O. (1994). Marine Algae of Northern Ireland. Ulster Museum, Belfast.

Classification: Biota; Plantae; Biliphyta; Rhodophyta; Eurhodophytina; Florideophyceae; Rhodymeniophycidae; Gigartinales; Calosiphoniaceae; Schmitzia

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Osborne Morton (2026). Schmitzia hiscockiana. Maggs et Guiry. [In] Priority species, Marine Biodiversity Portal NI. https://www2.habitas.org.uk/marbiop-ni/priorityaccounts.php?item=ZM5590. Accessed on 2026-07-28