BIOTIC Species Information for Saccorhiza polyschides
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Researched by | Nicola White |
Data supplied by | MarLIN |
Refereed by | This information is not refereed. |
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Taxonomy |
Scientific name | Saccorhiza polyschides |
Common name | Furbelows |
MCS Code | ZR359 |
Recent Synonyms | Saccorhiza bulbosa |
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Phylum | Chromophycota |
Subphylum | |
Superclass | |
Class | Phaeophyceae |
Subclass | |
Order | Laminariales |
Suborder | |
Family | Phyllariaceae |
Genus | Saccorhiza |
Species | polyschides |
Subspecies | |
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Additional Information | No text entered |
Taxonomy References |
Norton, 1970, Norton & Burrows, 1969, |
General Biology |
Growth form | Forest Foliose
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Feeding method | Photoautotroph
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Mobility/Movement | Permanent attachment
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Environmental position | Epilithic Epifloral
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Typical food types | Not relevant |
Habit | Attached |
Bioturbator | Not relevant |
Flexibility | High (>45 degrees) |
Fragility | Robust |
Size | Large(>50cm) |
Height | |
Growth Rate | 145 mm/week |
Adult dispersal potential | None |
Dependency | Independent |
Sociability | Solitary |
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Toxic/Poisonous? | No |
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General Biology Additional Information | - Saccorhiza polyschides is a fast growing, annual and opportunistic species. The obvious plant is a gender-less sporophyte which grows up to 4 m long and may grow at 2 m a month at the peak of the growth season in late spring. The large sporophytes are present on the shore from May until winter. In autumn they commence fruiting and start to decay, leaving behind the bulbous holdfast, which remains on the shore until it is washed off in late winter.
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The unusual holdfast of Saccorhiza polyschides is formed from a hollow bulbous growth above the sapling holdfast which expands to overwhelm it, sending out secondary haptera to attach to the substratum.
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The shape of the frond varies with the degree and nature of water movement. In sites of low water current plants produce broad undivided fronds, while those in areas of strong currents have long deeply divided fronds. Plants from wave exposed locations have short fronds divided into few sections. Experiments have shown that these variations are due to phenotypic rather than genotypic variation (Norton, 1978).
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Biology References |
Norton, 1970, Norton & Burrows, 1969, Norton, 1978, Birkett et al., 1998(b), |
Distribution and Habitat |
Distribution in Britain & Ireland | Recorded from the all coasts of Britain and Ireland, but absent from Northumberland to the Solent. |
Global distribution | Recorded from the coast of Norway as far north as Rorvik. It extends south to Britain, Ireland, France, Spain, and Morocco as far as Cape Jubi. It also penetrates into the eastern Mediterranean and there are isolated reports from the coast of Italy. |
Biogeographic range | Not researched |
Depth range | 0 -35m |
Migratory | Non-migratory / Resident |
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Distribution Additional Information | - Saccorhiza polyschides colonizes abraded surfaces such as sand-scoured rocks or boulders that are mobile in winter and is characteristic of much disturbed substrata.
- Plants grow to a maximum depth of 35 metres in Cornwall. The lower depth limit of the plants may be controlled by grazing from the sea urchin %Echinus esculentus%. When urchins have been removed, the lower limit of Saccorhiza polyschides has been found to extend by 3m.
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The species is not found in areas of reduced salinity. Lowered salinity reduces the rate of development and growth is irreversibly inhibited below 9 psu. The species competes for space with %Laminaria hyperborea% and the upper limit of Saccorhiza polyschides is related to the lower limit of %Laminaria hyperborea%. Where %Laminaria hyperborea% is absent the species may extend up to the extreme low water springs mark.
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Substratum preferences | Bedrock Large to very large boulders Small boulders Cobbles Pebbles
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Physiographic preferences | Open coast Offshore seabed Strait / sound Sealoch Ria / Voe
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Biological zone | Sublittoral Fringe Upper Infralittoral
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Wave exposure | Moderately Exposed Sheltered Very Sheltered Extremely Sheltered Ultra Sheltered
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Tidal stream strength/Water flow | Very Strong (>6 kn) Strong (3-6 kn) Moderately Strong (1-3 kn) Weak (<1 kn) Very Weak (negligible)
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Salinity | Full (30-40 psu)
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Habitat Preferences Additional Information | |
Distribution References |
Norton, 1970, Norton & Burrows, 1969, Birkett et al., 1998(b), Norton & South, 1969, Hardy & Guiry, 2003, |
Reproduction/Life History |
Reproductive type | Alternation of generations
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Developmental mechanism | Spores (sexual / asexual)
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Reproductive Season | October to May |
Reproductive Location | Insufficient information |
Reproductive frequency | Semelparous |
Regeneration potential |
No |
Life span | <1 year |
Age at reproductive maturity | <1 year |
Generation time | <1 year |
Fecundity | Insufficient information |
Egg/propagule size | Zoospores ca 5 µm diam. |
Fertilization type | External |
Larvae/Juveniles |
Larval/Juvenile dispersal potential | 100-1000m |
Larval settlement period | Insufficient information |
Duration of larval stage | <1 day |
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Reproduction Preferences Additional Information | - Saccorhiza polyschides has a typical Laminarian life history in which a macroscopic diploid sporophyte alternates with a microscopic haploid gametophyte.
- The species is an annual. Sporophytes typically have a life span of less than 10 months. However, plants produced late in the season may over-winter and live for 14-16 months.
- The base of the lamina, the stipe frills and the bulb are covered in unilocular sporangia, which produce zoospores by meiosis. Each sporangia contains 128 zoospores. The flagellated zoospores are about 5 microns in diameter and possess an eyespot which makes them strongly phototactic. The zoospores may be transported at least 200 m from the parent and they loose their flagella after 24 hrs and settle on the available substrata. 75% of the zoospores settle on the substrata with 24 hours.
- The zoospores develop into microscopic dioecious gametophytes. Gametophytes take the form of unicellular or filamentous structures. The male gametophytes are more branched than the females and have more numerous, smaller and paler cells. These become fertile in under 10 days in optimal conditions. Male gametophytes release motile sperm that fertilize eggs of female gametophytes, the resultant zygote develops into the new sporophyte.
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Reproduction References |
Norton, 1970, Norton & Burrows, 1969, Birkett et al., 1998(b), |