Pink sea fan (Eunicella verrucosa)
|Size||Height: up to 50, usually 25 cm (1)|
- A relative of tropical corals, the pink sea fan is formed by a colony of small anemone-like polyps.
- Different pink sea fan colonies are thought to be separate sexes.
- Pink sea fans can live for up to 50 years, and their age can be determined by counting growth rings, much like those seen in trees.
- In their adult form, colonies never move and remain fixed to a substrate by a ‘holdfast’.
The pink sea fan is classified as Vulnerable (VU) on the IUCN Red List (2). Protected under Schedule 5 of the Wildlife and Countryside Act 1981 (3).
Pink sea fans (Eunicella verrucosa) are formed from a colony of tiny polyps; they may be a deep pink to white in colour (1), and attach to the substrate with a broad base. Branches occur two to four centimetres above this base from a column which can reach 0.8 centimetres in diameter. Branching occurs in one plane, and the whole fan is orientated at right angles to the prevailing current in order to maximise the efficiency of filter feeding (4). The anemone-like polyps emerge from warty bumps along the branches (1).
The pink sea fan is found in the waters of the south west of England between north Pembrokeshire and Dorset. It is also known from the west of Ireland (3) and around south-west Europe (4), reaching as far south as the Mediterranean (3). Old records indicate that this species was once present in the English Channel up to the Thames Estuary (1).
The pink sea fan attaches to rocky substrata such as large stable boulders or upward facing bedrock. They only occur at depths below the level where algae dominate, often below 15 metres (3), with moderately strong currents or wave action (1).
Although there is no direct information on the reproduction of the pink sea fan, it is thought that larvae are short-lived and settle soon after release (5). It is a slow growing and long-lived species (specimens may reach 50 years old) and if a population is entirely lost from an area, recolonisation is likely to be very slow (5). The age can be determined (destructively) by the presence of internal growth rings, much like those of a tree (1). The pink sea fan provides habitat for the sea fan sea slug, (Tritonia nilsohdneri) and the rare sea fan anemone (Amphianthus dohrnii) (6).
This species is extremely vulnerable to physical disturbance (1). In the 1960s the pink sea fan was collected as souvenirs, which may have caused a long-term reduction in populations. Climate change may be a future concern, and damage may occur as a result of strikes by careless scuba divers' fins and entanglement in fishing nets. Smothering by seaweeds and other species may also cause the death of pink sea fans (3). Although classified as Nationally Scarce, this species is likely to have a wider range than current records indicate (1).
The pink sea fan is fully protected against killing, taking or injuring, and sale. It is a UK Biodiversity Action Plan (UK BAP) priority species, the resulting Species Action Plan aims to maintain the present distribution of the sea fan (3). The pink sea fan occurs in the Marine Nature Reserves (MNRs) of Lundy and Skomer; the zones of these MNRs were developed specifically to reflect the sensitivity of this species (3). As the pink sea fan is the host species for the sea anemone Amphianthus dohrnii, which is also a UK BAP priority, the conservation of these two species goes hand-in-hand (3). A project by The Marine Conservation Society is currently monitoring and assessing pink sea fans (5).
For more information on this species:
The Marine Life Information Network (MarLIN) species account:
Information authenticated by Dr Keith Hiscock of the Marine Biological Association of the UK:
- Algae: simple plants that lack roots, stems and leaves but contain the green pigment chlorophyll. Most occur in marine and freshwater habitats.
- Larvae: stage in an animal's lifecycle after it hatches from the egg. Larvae are typically very different in appearance to adults; they are able to feed and move around but usually are unable to reproduce.
- Polyp: typically sedentary soft-bodied component of cnidaria (corals, sea pens etc), which comprise of a trunk that is fixed at the base; the mouth is placed at the opposite end of the trunk, and is surrounded by tentacles.
Hiscock, K. 2000. Pink sea fan, Eunicella verrucosa. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. (November, 2001)
IUCN Red List (April, 2011)
UKBAP Species Action Plan (November, 2001)
Marine Conservation Society (November, 2001)
- Hiscock, K. (2003) Pers. comm.
Marine Life Awareness Pages. (November, 2001)