A colonial sea squirt (Morchellium argus)
Colonies of Morchellium argus.
Photographer: Paul Newland Copyright: Paul Newland
Distribution data supplied by the Ocean Biodiversity Information System (OBIS). To interrogate UK data visit the NBN Atlas.Map Help
| Researched by | Dr Keith Hiscock | Refereed by | This information is not refereed |
| Authority | (Milne Edwards, 1841) | ||
| Other common names | - | Synonyms | - |
Summary
Description
Clumps of pink or red lobes each about 4 cm long and consisting of many zooids. Distinguished from other polyclinids especially by the sand coating on the column.
Recorded distribution in Britain and Ireland
Recorded from all around the coasts of Britain and Ireland except parts of the eastern coast of England and parts of the eastern and southern coasts of Ireland. Few records from Shetland.Global distribution
Known from Britain and Ireland and parts of the French Atlantic coast.Habitat
Present on the shore mainly on vertical surfaces, under overhangs and in caves. In the sublittoral, often conspicuous amongst foliose algae in the lower infralittoral especially in wave sheltered areas.Depth range
+1 to -10 m chart datumIdentifying features
- Colonies of pink or red lobes joined at the base.
- Each lobe is about 4 cm long with a stalk diameter of about 1 cm.
- Each lobe has a long firm sand-coated stalk and a wider rounded head.
- The zooid has eight lobes on the oral siphon and a small pointed atrial languet with four red spots on the base of the oral siphon.
Additional information
No text entered
Listed by
- none -
Biology review
Taxonomy
| Phylum | Chordata | Sea squirts, fish, reptiles, birds and mammals |
| Class | Ascidiacea | Sea squirts |
| Order | Aplousobranchia | |
| Family | Polyclinidae | |
| Genus | Morchellium | |
| Authority | (Milne Edwards, 1841) | |
| Recent Synonyms | ||
Biology
| Typical abundance | Moderate density | ||
| Male size range | 4cm | ||
| Male size at maturity | |||
| Female size range | Small-medium(3-10cm) | ||
| Female size at maturity | |||
| Growth form | Cushion | ||
| Growth rate | |||
| Body flexibility | |||
| Mobility | |||
| Characteristic feeding method | Active suspension feeder, Non-feeding | ||
| Diet/food source | |||
| Typically feeds on | Suspended organic matter. | ||
| Sociability | |||
| Environmental position | Epifaunal | ||
| Dependency | Independent. | ||
| Supports | None | ||
| Is the species harmful? | Yes Moderate levels of toxicity were found against invertebrate larvae by Teo & Ryland (1995). | ||
Biology information
-none-Habitat preferences
| Physiographic preferences | Open coast, Offshore seabed, Strait / sound, Sea loch / Sea lough, Ria / Voe, Estuary, Enclosed coast / Embayment |
| Biological zone preferences | Lower eulittoral, Lower infralittoral, Sublittoral fringe, Upper infralittoral |
| Substratum / habitat preferences | Bedrock, Large to very large boulders, Small boulders |
| Tidal strength preferences | Moderately Strong 1 to 3 knots (0.5-1.5 m/sec.), Strong 3 to 6 knots (1.5-3 m/sec.), Very Weak (negligible), Weak < 1 knot (<0.5 m/sec.) |
| Wave exposure preferences | Exposed, Extremely sheltered, Moderately exposed, Sheltered, Ultra sheltered, Very sheltered |
| Salinity preferences | Full (30-40 psu), Variable (18-40 psu) |
| Depth range | +1 to -10 m chart datum |
| Other preferences | |
| Migration Pattern | Non-migratory / resident |
Habitat Information
No text enteredLife history
Adult characteristics
| Reproductive type | Permanent (synchronous) hermaphrodite | |
| Reproductive frequency | ||
| Fecundity (number of eggs) | 100-1,000 | |
| Generation time | <1 year | |
| Age at maturity | ||
| Season | June - October | |
| Life span | 1-2 years |
Larval characteristics
| Larval/propagule type | - |
| Larval/juvenile development | Lecithotrophic |
| Duration of larval stage | < 1 day |
| Larval dispersal potential | 100 -1000 m |
| Larval settlement period | Insufficient information |
Life history information
Eggs are about 0.34 mm diameter. Larvae are held in the atrial cavity and have a trunk about 0.8 mm long. The free-swimming period of the larva is about 2-3 hours. Berrill (1950) suggests that brooding colonies are present in September and October but records in the Plymouth Marine Fauna suggest breeding June to September.Sensitivity review
The MarLIN sensitivity assessment approach used below has been superseded by the MarESA (Marine Evidence-based Sensitivity Assessment) approach (see menu). The MarLIN approach was used for assessments from 1999-2010. The MarESA approach reflects the recent conservation imperatives and terminology and is used for sensitivity assessments from 2014 onwards.
Physical pressures
| Intolerance | Recoverability | Sensitivity | Evidence/Confidence | |
| High | High | Moderate | High | |
| Colonies are sessile and will therefore be lost along with their substratum. Larvae disperse in the water column so that, providing coonies survive nearby, recovery will occur following the late summer larval dispersal phase. | ||||
| High | High | Moderate | Moderate | |
| Colonies rely on being able to pump water for respiration and feeding and cannot extend to any great extent to above layer of smothering sediment. Whilst they may survive for a little time in conditions where they are unable to draw water though the siphons, it is expected that they would be killed by smothering that lasts more than a few days. Larvae disperse in the water column so that, providing colonies survive nearby, recovery will occur following the late summer larval dispersal phase. | ||||
| Low | High | Low | Moderate | |
| Colonies produce mucous which is shed to remove deposited silt. Colonies live in areas where high suspended sediment levels commonly occur and it is therefore expected that intolerance is low. Larvae disperse in the water column so that, providing colonies survive nearby, recovery will occur following the late summer larval dispersal phase. | ||||
| No information | ||||
| High | High | Moderate | Moderate | |
| Colonies are likely to dry and be damaged by exposure to air and especially sunshine in non-damp situations on the shore. Larvae disperse in the water column so that, providing colonies survive nearby, recovery will occur following the late summer larval dispersal phase. | ||||
| Intermediate | High | Low | Low | |
| Colonies live in the intertidal only in locations where damp conditions prevail (under overhangs and under boulders). In such a situation, there will be some tolerance to increased emersion times but it is likely that colonies will not survive during periods of hot drying weather. Larvae disperse in the water column so that, providing colonies survive nearby, recovery will occur following the late summer larval dispersal phase. | ||||
| No information | ||||
| Low | High | Low | Low | |
| Morchellium argus lives in a wide range of flow regimes. Larvae disperse in the water column so that, providing colonies survive nearby, recovery will occur following the late summer larval dispersal phase. | ||||
| No information | ||||
| Low | Very high | Very Low | Moderate | |
| Morchellium is in the middle of its geographical range in Britain and Ireland suggesting that it will survive slightly higher and lower temperatures. | ||||
| Intermediate | High | Low | Moderate | |
| Morchellium is in the middle of its geographical range in Britain and Ireland suggesting that it will survive slightly higher and lower temperatures. Crisp (1964) did not record any specific effects on Morchellium following the severe cold winter of 1962/63 but noted that compound ascidians were slower to recover from winter de-differentiation, or may have been killed in North Wales. | ||||
| Low | High | Low | Low | |
| Morchellium lives in areas such as the entrances to estuaries where highly turbid conditions occur from time-to-time especially as a result of river run-off. Morchellium does not rely on light penetration and so, although populations seem to be restricted to shallow depths, is unlikely to be affected by changes in light levels. | ||||
| No information | ||||
| Low | High | Low | Low | |
| Morchellium lives in a wide range of flow regimes although vigorous wave action may detach colonies. Larvae disperse in the water column so that, providing colonies survive nearby, recovery will occur following the late summer larval dispersal phase. | ||||
| No information | ||||
| Tolerant | Not relevant | Not sensitive | High | |
| Tunicates are not known to have organs sensitive to noise. | ||||
| Tolerant | Not relevant | Not sensitive | High | |
| Tunicates are not known to respond to visual presence. | ||||
| Intermediate | High | Low | Moderate | |
| Colonies are very flexible and soft providing a buffer against external abrasion from such factors as a fishing pot landing on a colony. Morchellium lives in a wide range of flow regimes although high currents or vigorous wave action may detach colonies. However, individuals and colonies may be scraped off the rock by an anchor or passing dredge. Intolerance is therefore assessed as intermediate. Larvae disperse in the water column so that, providing colonies survive nearby, recovery will occur following the late summer larval dispersal phase. | ||||
| High | High | Moderate | Moderate | |
| The colonies are attached permanently to the substratum and will not re-attach so that displacement, even if to a suitable habitat, would most likely result in mortality. Morchellium lives in a wide range of flow regimes although high currents or vigorous wave action may detach colonies. Larvae disperse in the water column so that, providing colonies survive nearby, recovery will occur following the late summer larval dispersal phase. | ||||
Chemical pressures
| Intolerance | Recoverability | Sensitivity | Evidence/Confidence | |
| No information | Not relevant | No information | Not relevant | |
| No information | Not relevant | No information | Not relevant | |
| No information | Not relevant | No information | Not relevant | |
| No information | Not relevant | No information | Not relevant | |
| Tolerant | Not relevant | Not sensitive | Moderate | |
| Morchellium occurs where nutrient levels are likely to reach high levels (at the entrance to estuaries). The species is dependant on food sources that are not likely to be affected by local nutrient concentrations. | ||||
| Intermediate | High | Low | Low | |
| Colonies occur in full and variable salinity conditions suggesting significant tolerance to at least lowered salinity. Larvae disperse in the water column so that, providing colonies survive nearby, recovery will occur following the late summer larval dispersal phase. | ||||
| No information | ||||
| No information | Not relevant | No information | Not relevant | |
Biological pressures
| Intolerance | Recoverability | Sensitivity | Evidence/Confidence | |
| No information | Not relevant | No information | Not relevant | |
| No information | Not relevant | No information | Not relevant | |
| Intermediate | High | Low | Moderate | |
| Larvae disperse in the water column so that, providing colonies survive nearby, recovery will occur following the late summer larval dispersal phase. | ||||
| Intermediate | High | Low | ||
| where extraction of other species from under boulder habitats results in the stones being left downside up, there will be significant damage to Morchellium colinies. However, most other forms of extraction of species that co-occur with Morchellium (especially deployment of pots or creels to catch shellfish) are unlikely to cause damage to Morchellium. | ||||
Additional information
Importance review
Policy/legislation
- no data -
Status
| National (GB) importance | - | Global red list (IUCN) category | - |
Non-native
| Native | - | ||
| Origin | - | Date Arrived | - |
Importance information
-none-Bibliography
Berrill, N.J., 1950. The Tunicata with an account of the British species. London: Ray Society.
Crisp, D.J. (ed.), 1964. The effects of the severe winter of 1962-63 on marine life in Britain. Journal of Animal Ecology, 33, 165-210.
Crisp, D.J., Southward, A.J. & Southward, E.C., 1981. On the distribution of the intertidal barnacles Chthamalus stellatus, Chthamalus montagui and Euraphia depressa. Journal of the Marine Biological Association of the United Kingdom, 61, 359-380.
Howson, C.M. & Picton, B.E., 1997. The species directory of the marine fauna and flora of the British Isles and surrounding seas. Belfast: Ulster Museum. [Ulster Museum publication, no. 276.]
JNCC (Joint Nature Conservation Committee), 1999. Marine Environment Resource Mapping And Information Database (MERMAID): Marine Nature Conservation Review Survey Database. [on-line] http://www.jncc.gov.uk/mermaid
MBA (Marine Biological Association), 1957. Plymouth Marine Fauna. Plymouth: Marine Biological Association of the United Kingdom.
Picton, B.E. & Costello, M.J., 1998. BioMar biotope viewer: a guide to marine habitats, fauna and flora of Britain and Ireland. [CD-ROM] Environmental Sciences Unit, Trinity College, Dublin.
Teo, S.L.-M. & Ryland, J.S., 1995. Potential antifouling mechanisms using toxic chemicals in some British ascidians. Journal of Experimental Marine Biology and Ecology, 188, 49-62.
Datasets
Centre for Environmental Data and Recording, 2018. Ulster Museum Marine Surveys of Northern Ireland Coastal Waters. Occurrence dataset https://www.nmni.com/CEDaR/CEDaR-Centre-for-Environmental-Data-and-Recording.aspx accessed via NBNAtlas.org on 2018-09-25.
Dorset Environmental Records Centre, 2018. Ross Coral Mapping Project - NBN South West Pilot Project Case Studies. Occurrence dataset:https://doi.org/10.15468/mnlzxc accessed via GBIF.org on 2018-09-25.
Fenwick, 2018. Aphotomarine. Occurrence dataset http://www.aphotomarine.com/index.html Accessed via NBNAtlas.org on 2018-10-01
Kent Wildlife Trust, 2018. Kent Wildlife Trust Shoresearch Intertidal Survey 2004 onwards. Occurrence dataset: https://www.kentwildlifetrust.org.uk/ accessed via NBNAtlas.org on 2018-10-01.
Manx Biological Recording Partnership, 2018. Isle of Man historical wildlife records 1990 to 1994. Occurrence dataset:https://doi.org/10.15468/aru16v accessed via GBIF.org on 2018-10-01.
National Trust, 2017. National Trust Species Records. Occurrence dataset: https://doi.org/10.15468/opc6g1 accessed via GBIF.org on 2018-10-01.
NBN (National Biodiversity Network) Atlas. Available from: https://www.nbnatlas.org.
Norfolk Biodiversity Information Service, 2017. NBIS Records to December 2016. Occurrence dataset: https://doi.org/10.15468/jca5lo accessed via GBIF.org on 2018-10-01.
OBIS (Ocean Biodiversity Information System), 2023. Global map of species distribution using gridded data. Available from: Ocean Biogeographic Information System. www.iobis.org. Accessed: 2023-03-31
South East Wales Biodiversity Records Centre, 2018. SEWBReC Marine and other Aquatic Invertebrates (South East Wales). Occurrence dataset:https://doi.org/10.15468/zxy1n6 accessed via GBIF.org on 2018-10-02.
Citation
This review can be cited as:
Last Updated: 09/11/2006
