Branched antenna sea fir (Nemertesia ramosa)
Distribution data supplied by the Ocean Biodiversity Information System (OBIS). To interrogate UK data visit the NBN Atlas.Map Help
Researched by | Angus Jackson | Refereed by | Dr Rob Hughes |
Authority | (Lamarck, 1816) | ||
Other common names | Branched sea beard, Branched antenna hydroid | Synonyms | - |
Summary
Description
Nemertesia ramosa is a colonial hydroid that lives in small aggregations. Individual colonies consist of an upright and irregularly branched stem up to about 15 cm in height. An individual may have several other colonies attached to the stem. The main stems bear whorls of fine side branches of even length and upwardly pointing, arranged in groups of 6. The hydroid is yellow/orange in colour and is usually more pigmented than the similar Nemertesia antennina.
Recorded distribution in Britain and Ireland
Widely distributed round all British and Irish coasts.Global distribution
In the North Atlantic; from Iceland down to north-west Africa. In the Mediterranean; the Straight of Gibraltar, some parts of the Spanish coast, Israel and Italy. In the Indian Ocean; coasts of South Africa and Mozambique.Habitat
The colonies of this species live in small aggregations, usually with several colonies attached to a single 'main' stem. The colonies are typically attached to hard substrata such as bedrock, boulders, pebbles and shells. The hydroid attaches to the substratum using hydrorhizae which form a holdfast. The species lives in slight to moderately flowing water and is intolerant of wave action. Nemertesia ramosa has very similar habitat preferences to Nemertesia antenninaDepth range
10-500Identifying features
- An orange-yellow hydroid or sea-fir that reaches 15 cm in height.
- The colony consists of an upright main stem (hydrocaulus) that branches occasionally and irregularly.
- The main stems bear fine, even length side (secondary) branches (hydrocladia) arranged in groups of six.
- Secondary branches are whorled (3-dimensional).
Additional information
No text entered
Listed by
- none -
Biology review
Taxonomy
Level | Scientific name | Common name |
---|---|---|
Phylum | Cnidaria | Sea anemones, corals, sea firs & jellyfish |
Class | Hydrozoa | White weeds, sea firs, sea beard and siphonophores; hydroids |
Order | Leptothecata | |
Family | Plumulariidae | |
Genus | Nemertesia | |
Authority | (Lamarck, 1816) | |
Recent Synonyms |
Biology
Parameter | Data | ||
---|---|---|---|
Typical abundance | High density | ||
Male size range | up to 15cm | ||
Male size at maturity | 7-10cm | ||
Female size range | 7-10cm | ||
Female size at maturity | |||
Growth form | Pinnate | ||
Growth rate | 2.6 - 4.6cm/month | ||
Body flexibility | |||
Mobility | Sessile, permanent attachment | ||
Characteristic feeding method | Passive suspension feeder | ||
Diet/food source | |||
Typically feeds on | seston | ||
Sociability | Colonial | ||
Environmental position | Epifaunal | ||
Dependency | Independent. | ||
Supports | Host See additional information | ||
Is the species harmful? | No |
Biology information
Very little information is directly available on Nemertesia ramosa. Completion of most of the fields has been done through extrapolation from the very similar species Nemertesia antennina.
The main stems of Nemertesia ramosa branch occasionally whereas those of Nemertesia antennina do not. The size at maturity for Nemertesia ramosa (a smaller species) may be less than that for Nemertesia antennina. Growth rates for Nemertesia ramosa may also be lower than those recorded for Nemertesia antennina. Growth rates are highest in the summer and lowest in the winter. An individual planula larva gives rise to a colony (sometimes referred to as an individual). These colonies (individuals) are gregarious. The feeding polyps of this species are too large to be withdrawn into the protective theca. Nemertesia ramosa is fed on by a variety of sea slugs including Doto fragilis, Doto cuspidata, Lomanotus genei, and by the sea spider Endeis spinosa.
Ansín Agís et al (2001) list the following species as epibionts on Nemertesia ramosa: Plumularia setacea, Clytia gracilis, Clytia hemisphaerica, Scalpellum scalpellum, Antennella secundaria, Aglaopheria tubulifera, Plumularia setacea, Obelia bidentata, Camapnularia hincksii, Zygophylax biarmata, Filellum serratum and Modeeria rotunda.
Habitat preferences
Parameter | Data |
---|---|
Physiographic preferences | Open coast, Offshore seabed, Sea loch or Sea lough, Ria or Voe, Estuary, Enclosed coast or Embayment |
Biological zone preferences | Lower circalittoral, Lower infralittoral, Upper circalittoral |
Substratum / habitat preferences | Bedrock, Cobbles, Gravel / shingle, Large to very large boulders, Maerl, Pebbles, Small boulders |
Tidal strength preferences | Moderately strong 1 to 3 knots (0.5-1.5 m/sec.), Very weak (negligible), Weak < 1 knot (<0.5 m/sec.) |
Wave exposure preferences | Extremely sheltered, Sheltered, Ultra sheltered, Very sheltered |
Salinity preferences | Data deficient |
Depth range | 10-500 |
Other preferences | No text entered |
Migration Pattern | Non-migratory or resident |
Habitat Information
The species is not tolerant of wave action. Where exposed to swell it is not usually found at less than 30 m. It may be found at shallower depths in sheltered locations. Some regeneration may occur from broken stems but this is generally found in few individuals.Life history
Adult characteristics
Parameter | Data |
---|---|
Reproductive type | Vegetative |
Reproductive frequency | Semelparous or monotely |
Fecundity (number of eggs) | 11-100 |
Generation time | <1 year |
Age at maturity | Insufficient information |
Season | Not relevant |
Life span | <1 year |
Larval characteristics
Parameter | Data |
---|---|
Larval/propagule type | - |
Larval/juvenile development | Lecithotrophic |
Duration of larval stage | < 1 day |
Larval dispersal potential | 10 -100 m |
Larval settlement period | Insufficient information |
Life history information
Very little information is directly available on Nemertesia ramosa. Completion of most of the fields has been done through extrapolation from the very similar species Nemertesia antennina from Hughes (1977).
- Males and females are separate but similar, differentiation being possible through the colour of the reproductive tissues, females being orange (yolk) and males white.
- Allocation of reproductive frequency is difficult. An individual colony will only reproduce once during its 4-5 month lifespan but this reproductive effort is probably spread over an extended period rather than a short episode. In Nemertesia ramosa, gonothecae have been observed in all months of the year with the exception of January, October, November and December (Ansín Agíl et al, 2001).
- Information on fecundity is sparse and has only been recorded for Nemertesia antennina as the mean length of reproductive areas in relation to the total length. Recorded values are only an estimate.
- The planula larvae are released from the gonothecae and drop off the end of the hydrocladium. They settle and metamorphose between 12 and 24 hours. This is the only mobile stage in the life cycle of Nemertesia antennina and therefore very important for dispersal.
- Dispersal distance is dependent on current speed, turbulence and the height at which the larvae are released but in Torbay, the distance is thought to be between 5 and 50 m.
- The dense larva reduces sinking rates by producing a mucous thread (without the thread the larvae sink at 5 mm per second in still water).
- Once the larva lands on the seabed, further dispersal is limited to crawling although this probably lasts for no more than 1-2 hours. Crawling speeds may reach up to 5 mm per minute on smooth surfaces so the planula larvae will probably not move further than 1 to 2 m before settlement.
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
Use / to open/close text displayed
Intolerance | Recoverability | Sensitivity | Evidence / Confidence | |
Substratum loss [Show more]Substratum lossBenchmark. All of the substratum occupied by the species or biotope under consideration is removed. A single event is assumed for sensitivity assessment. Once the activity or event has stopped (or between regular events) suitable substratum remains or is deposited. Species or community recovery assumes that the substratum within the habitat preferences of the original species or community is present. Further details EvidenceThis species is permanently fixed to the substratum so substratum loss would cause death. See information on recoverability below. | High | Moderate | Moderate | Low |
Smothering [Show more]SmotheringBenchmark. All of the population of a species or an area of a biotope is smothered by sediment to a depth of 5 cm above the substratum for one month. Impermeable materials, such as concrete, oil, or tar, are likely to have a greater effect. Further details. EvidenceNemertesia ramosa is an upright hydroid with a height of up to 15 cm. The colony structure is fairly tough and flexible. Smothering with 5 cm of sediment may cover over some individuals, others may just have the lower section of the main stem covered. Hughes (1977) found that maturing hydroids that had been smothered with detritus and silt lost most of the hydrocladia and hydranths. After one month, the hydroids were seen to have recovered but although neither the growth rate nor the reproductive potential appeared to have been affected, the viability of the planulae may have been affected. Therefore, an intolerance of intermediate has been recorded. | Intermediate | Very high | Low | Low |
Increase in suspended sediment [Show more]Increase in suspended sedimentBenchmark. An arbitrary short-term, acute change in background suspended sediment concentration e.g., a change of 100 mg/l for one month. The resultant light attenuation effects are addressed under turbidity, and the effects of rapid settling out of suspended sediment are addressed under smothering. Further details EvidenceNemertesia ramosa is a passive suspension feeder, extracting seston from the water column. Increased siltation may clog up the feeding apparatus, requiring energetic expenditure to clear. Recovery from the energetic expenditure of clearing the feeding apparatus is likely to take only a few days. | Intermediate | Immediate | Very Low | Low |
Decrease in suspended sediment [Show more]Decrease in suspended sedimentBenchmark. An arbitrary short-term, acute change in background suspended sediment concentration e.g., a change of 100 mg/l for one month. The resultant light attenuation effects are addressed under turbidity, and the effects of rapid settling out of suspended sediment are addressed under smothering. Further details Evidence | No information | |||
Desiccation [Show more]Desiccation
EvidenceThe species is entirely sub-tidal and typically found below 10 m unless in very sheltered areas. Exposure to desiccating influences will probably cause death. See information on recoverability below. | High | Moderate | Moderate | Low |
Increase in emergence regime [Show more]Increase in emergence regimeBenchmark. A one hour change in the time covered or not covered by the sea for a period of one year. Further details EvidenceThe species is entirely sub-tidal and typically found below 10m unless in very sheltered areas. Emergence for an hour will probably cause death. See information on recoverability below. | High | Moderate | Moderate | Low |
Decrease in emergence regime [Show more]Decrease in emergence regimeBenchmark. A one hour change in the time covered or not covered by the sea for a period of one year. Further details Evidence | No information | |||
Increase in water flow rate [Show more]Increase in water flow rateA change of two categories in water flow rate (view glossary) for 1 year, for example, from moderately strong (1-3 knots) to very weak (negligible). Further details EvidenceThe species lives in very weak to moderate water flows. Increases above this may provide more food but may also prevent the individual hydranths of the colony from remaining extended and feeding therefore, an intolerance of intermediate has been recorded. | Intermediate | High | Low | Low |
Decrease in water flow rate [Show more]Decrease in water flow rateA change of two categories in water flow rate (view glossary) for 1 year, for example, from moderately strong (1-3 knots) to very weak (negligible). Further details Evidence | No information | |||
Increase in temperature [Show more]Increase in temperature
For intertidal species or communities, the range of temperatures includes the air temperature regime for that species or community. Further details EvidenceInsufficient | No information | No information | No information | Not relevant |
Decrease in temperature [Show more]Decrease in temperature
For intertidal species or communities, the range of temperatures includes the air temperature regime for that species or community. Further details Evidence | No information | |||
Increase in turbidity [Show more]Increase in turbidity
EvidenceThe species probably has very limited facility for visual perception. It occurs down to depths of 500 m so attenuation of light is probably of little importance. | Tolerant | Not relevant | Not sensitive | Low |
Decrease in turbidity [Show more]Decrease in turbidity
Evidence | No information | |||
Increase in wave exposure [Show more]Increase in wave exposureA change of two ranks on the wave exposure scale (view glossary) e.g., from Exposed to Extremely exposed for a period of one year. Further details EvidenceThe species is intolerant of high wave exposure and so is only found in sheltered areas. Increases in wave exposure above the preferred limits is likely to cause death, either through physical damage or prevention of feeding. See information on recoverability below. | High | Moderate | Moderate | Low |
Decrease in wave exposure [Show more]Decrease in wave exposureA change of two ranks on the wave exposure scale (view glossary) e.g., from Exposed to Extremely exposed for a period of one year. Further details Evidence | No information | |||
Noise [Show more]Noise
EvidenceThe species is likely to have limited facility for detecting noise. | Tolerant | Not relevant | Not sensitive | High |
Visual presence [Show more]Visual presenceBenchmark. The continuous presence for one month of moving objects not naturally found in the marine environment (e.g., boats, machinery, and humans) within the visual envelope of the species or community under consideration. Further details EvidenceThe species probably has very limited facility for visual perception. It occurs down to depths of 500 m. Visual disturbance is probably of little importance. | Tolerant | Not relevant | Not sensitive | High |
Abrasion & physical disturbance [Show more]Abrasion & physical disturbanceBenchmark. Force equivalent to a standard scallop dredge landing on or being dragged across the organism. A single event is assumed for assessment. This factor includes mechanical interference, crushing, physical blows against, or rubbing and erosion of the organism or habitat of interest. Where trampling is relevant, the evidence and trampling intensity will be reported in the rationale. Further details. EvidenceAlthough the species is quite flexible and robust, abrasion may cause displacement, physical damage to the colonies or death. For example, erect epifauna have been reported to be particularly vulnerable to damage by fishing gear. For example, Magorrian & Service (1998) reported that trawling for queen scallops resulted in removal of emergent epifauna and damage to horse mussel beds in Strangford Lough. They suggested that the emergent epifauna were more intolerant than the horse mussels themselves and reflected early signs of damage (Service & Magorrian, 1997; Magorrian & Service, 1998; Service 1998). Veale et al., 2000 reported that the abundance, biomass and production of epifaunal assemblages decreased with increasing fishing effort. Therefore, a passing scallop dredge is likely to damage or remove a proportion of the population and an intolerance of intermediate has been recorded. | Intermediate | High | Low | Low |
Displacement [Show more]DisplacementBenchmark. Removal of the organism from the substratum and displacement from its original position onto a suitable substratum. A single event is assumed for assessment. Further details EvidenceThe colonies of this species are permanently attached either to the substratum or to other colonies. On displacement individual colonies would be unable to re-attach and therefore an intolerance of high has been recorded. See information on recoverability below. | High | Moderate | Moderate | Low |
Chemical pressures
Use [show more] / [show less] to open/close text displayed
Intolerance | Recoverability | Sensitivity | Evidence / Confidence | |
Synthetic compound contamination [Show more]Synthetic compound contaminationSensitivity is assessed against the available evidence for the effects of contaminants on the species (or closely related species at low confidence) or community of interest. For example:
The evidence used is stated in the rationale. Where the assessment can be based on a known activity then this is stated. The tolerance to contaminants of species of interest will be included in the rationale when available; together with relevant supporting material. Further details. EvidenceInsufficient | No information | No information | No information | Not relevant |
Heavy metal contamination [Show more]Heavy metal contaminationEvidenceInsufficient | No information | No information | No information | Not relevant |
Hydrocarbon contamination [Show more]Hydrocarbon contaminationEvidenceInsufficient | No information | No information | No information | Not relevant |
Radionuclide contamination [Show more]Radionuclide contaminationEvidenceInsufficient | No information | No information | No information | Not relevant |
Changes in nutrient levels [Show more]Changes in nutrient levelsEvidenceInsufficient | No information | No information | No information | Not relevant |
Increase in salinity [Show more]Increase in salinity
EvidenceInsufficient | No information | No information | No information | Not relevant |
Decrease in salinity [Show more]Decrease in salinity
Evidence | No information | |||
Changes in oxygenation [Show more]Changes in oxygenationBenchmark. Exposure to a dissolved oxygen concentration of 2 mg/l for one week. Further details. EvidenceCole et al. (1999) suggest possible adverse effects on marine species below 4 mg/l and probable adverse effects below 2mg/l. However, there is no information about Nemertesia ramosa tolerance to changes in oxygenation. | No information | No information | No information | Not relevant |
Biological pressures
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Intolerance | Recoverability | Sensitivity | Evidence / Confidence | |
Introduction of microbial pathogens/parasites [Show more]Introduction of microbial pathogens/parasitesBenchmark. Sensitivity can only be assessed relative to a known, named disease, likely to cause partial loss of a species population or community. Further details. EvidenceInsufficient | No information | No information | No information | Not relevant |
Introduction of non-native species [Show more]Introduction of non-native speciesSensitivity assessed against the likely effect of the introduction of alien or non-native species in Britain or Ireland. Further details. EvidenceInsufficient | No information | No information | No information | Not relevant |
Extraction of this species [Show more]Extraction of this speciesBenchmark. Extraction removes 50% of the species or community from the area under consideration. Sensitivity will be assessed as 'intermediate'. The habitat remains intact or recovers rapidly. Any effects of the extraction process on the habitat itself are addressed under other factors, e.g. displacement, abrasion and physical disturbance, and substratum loss. Further details. EvidenceIt is highly unlikely that the species would be extracted for any reason. | Not relevant | Not relevant | Not relevant | Low |
Extraction of other species [Show more]Extraction of other speciesBenchmark. A species that is a required host or prey for the species under consideration (and assuming that no alternative host exists) or a keystone species in a biotope is removed. Any effects of the extraction process on the habitat itself are addressed under other factors, e.g. displacement, abrasion and physical disturbance, and substratum loss. Further details. EvidenceNemertesia ramosa has no known obligate relationships. | Tolerant | Not relevant | Not sensitive | Low |
Additional information
Recoverability. Detailed information on reproduction in this species is not known although fecundity is not particularly high. The larvae of Nemertesia ramosa are passive drifters, quite dense and have limited dispersal potential, dependent on water flow rates near the seabed. In a study of the long-term effects of scallop dredging in the Irish Sea, Bradshaw et al. (2002) noted that Nemertesia spp. increased in abundance, presumably because of their powers of regeneration, good local recruitment and ability to colonize newly exposed substratum quickly. In Nemertesia antennina, reproduction occurs regularly, there being three generations per year. The presence of adults stimulates larval settlement therefore if any adults remain, reproduction is likely to result in local recruitment.
Importance review
Policy/legislation
- no data -
Status
National (GB) importance | - | Global red list (IUCN) category | - |
Non-native
Parameter | Data |
---|---|
Native | - |
Origin | - |
Date Arrived | - |
Importance information
In Torbay, Nemertesia antennina, a similar species, has been recorded as hosting more than 150 epizoic species, most of which are not present on other local substrata.Bibliography
Ansín Agís, J., Ramil, F. & Vervoort, W., 2001. Atlantic Leptolida (Hydrozoa, Cnidaria) of the families Aglaopheniidae, Halopterididae, Kirchenpaueriidae and Plumulariidae collected during the CANCAP and Mauritania-II expeditions of the National Museum of Natural History, Leiden, the Netherlands. Zoologische Verhandelingen, no. 233, 268 pp.
Bradshaw, C., Veale, L.O., Hill, A.S. & Brand, A.R., 2002. The role of scallop-dredge disturbance in long-term changes in Irish Sea benthic communities: a re-analysis of an historical dataset. Journal of Sea Research, 47, 161-184. DOI https://doi.org/10.1016/S1385-1101(02)00096-5
Gili, J-M. & Hughes, R.G., 1995. The ecology of marine benthic hydroids. Oceanography and Marine Biology: an Annual Review, 33, 351-426.
Hayward, P.J. & Ryland, J.S. (ed.) 1995b. Handbook of the marine fauna of North-West Europe. Oxford: Oxford University Press.
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.]
Hughes, R.G., 1977. Aspects of the biology and life-history of Nemertesia antennina (L.) (Hydrozoa: Plumulariidae). Journal of the Marine Biological Association of the United Kingdom, 57, 641-657.
Hughes, R.G., 1978. Life-histories and abundance of epizoites of the hydroid Nemertesia antennina (L.) Journal of the Marine Biological Association of the United Kingdom, 58, 313-332.
Jones, N.S., 1951. The bottom fauna of the south of the Isle of Man. Journal of Animal Ecology, 20, 132-144.
Magorrian, B.H. & Service, M., 1998. Analysis of underwater visual data to identify the impact of physical disturbance on horse mussel (Modiolus modiolus) beds. Marine Pollution Bulletin, 36 (5), 354-359. DOI https://doi.org/10.1016/s0025-326x(97)00192-6
Picton, B.E. & Morrow, C.C., 2004. Nemertesia ramosa Lamouroux, 1816. http://www.habitas.org.uk/marinelife/species.asp?item=D5990, 2004-09-14
Service, M. & Magorrian, B.H., 1997. The extent and temporal variation of disturbance to epibenthic communities in Strangford Lough, Northern Ireland. Journal of the Marine Biological Association of the United Kingdom, 77, 1151-1164.
Service, M., 1998. Recovery of benthic communities in Strangford Lough following changes in fishing practice. ICES Council Meeting Paper, CM 1998/V.6, 13pp., Copenhagen: International Council for the Exploration of the Sea (ICES).
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.
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, 2022. Isle of Man historical wildlife records 1990 to 1994. Occurrence dataset:https://doi.org/10.15468/aru16v accessed via GBIF.org on 2024-09-27.
NBN (National Biodiversity Network) Atlas. Available from: https://www.nbnatlas.org.
OBIS (Ocean Biodiversity Information System), 2024. Global map of species distribution using gridded data. Available from: Ocean Biogeographic Information System. www.iobis.org. Accessed: 2024-12-11
South East Wales Biodiversity Records Centre, 2023. SEWBReC Marine and other Aquatic Invertebrates (South East Wales). Occurrence dataset:https://doi.org/10.15468/zxy1n6 accessed via GBIF.org on 2024-09-27.
Citation
This review can be cited as:
Last Updated: 15/09/2004