BIOTIC

BIOTIC Species Information for Ahnfeltia plicata

Researched by

Will Rayment

Data supplied by

MarLIN

Refereed by

Dr Fabio Rindi

Taxonomy

Scientific name

Ahnfeltia plicata

Common name

A red seaweed

MCS Code

ZM186

Recent Synonyms

None

Phylum

Rhodophycota

Subphylum

Superclass

Class

Rhodophyceae

Subclass

Florideophycidae

Order

Ahnfeltiales

Suborder

Family

Ahnfeltiaceae

Genus

Ahnfeltia

Species

plicata

Subspecies

Additional Information

Taxonomy References

Fish & Fish, 1996, Dickinson, 1963, Dixon & Irvine, 1977, Maggs & Pueschel, 1989, Howson & Picton, 1997,

General Biology

Growth form

Foliose
Turf
Crustose soft

Feeding method

Photoautotroph

Mobility/Movement

Permanent attachment

Environmental position

Epilithic

Typical food types

Not relevant

Habit

Attached

Bioturbator

Not relevant

Flexibility

High (>45 degrees)

Fragility

Intermediate

Size

Medium(11-20 cm)

Height

Growth Rate

See additional information

Adult dispersal potential

None

Dependency

Independent

Sociability

Solitary

Toxic/Poisonous?

General Biology Additional Information

Growth rate
Maggs & Pueschel (1989) recorded observations on growth of Ahnfeltia plicata from Nova Scotia. 4 months after germination of carpospores, tetrasporophyte crusts had grown up to 2.6 mm in diameter. 2 months after germination of tetraspores, the basal holdfast had reached 1.1 mm in diameter, with numerous hair like fronds emerging. After 14 months the axes had grown up to 50 mm in length.
In a continuous spray culture with water at 8-11°C and light intensities of 40-60 µE/m²/s, mean apical growth of Ahnfeltia plicata was 17.2 µm/day over 19 days (Indergaard et al., 1986). Permanently immersed plants under the same conditions grew at approximately 7 µm/day. Conversely, percentage biomass increase was greater under the permanent immersion regime; 0.57% increase in mass/day vs. 0.20% for the plants in spray culture (Indergaard et al., 1986).

Biology References

Fish & Fish, 1996, Dickinson, 1963, Dixon & Irvine, 1977, Maggs & Pueschel, 1989, Indergaard et al., 1986, Bird et al., 1991,

Distribution and Habitat

Distribution in Britain & Ireland

Occurs on all coasts of Britain and Ireland. There is a paucity of records from south east England, reflecting a lack of suitable substrata.

Global distribution

Occurs in Europe from northern Russia to southern Portugal and in the Baltic Sea. Occurs in the Americas from arctic Canada to Mexico and is widely distributed in the Indian and Pacific Oceans.

Biogeographic range

Not researched

Depth range

lower shore to 22 m

Migratory

Non-migratory / Resident

Distribution Additional Information

Lüning (1990) suggested that Ahnfeltia plicata typically occurs as an understory algae beneath Laminaria sp. at depths of 1.5 to 4 m.

Substratum preferences

Bedrock
Cobbles
Pebbles
Coarse clean sand

Physiographic preferences

Open coast
Strait / sound
Enclosed coast / Embayment

Biological zone

Lower Eulittoral
Upper Infralittoral
Sublittoral Fringe
Lower Infralittoral

Wave exposure

Exposed
Moderately Exposed
Sheltered

Tidal stream strength/Water flow

Moderately Strong (1-3 kn)
Weak (<1 kn)

Salinity

Full (30-40 psu)
Variable (18-40 psu)
Reduced (18-30 psu)

Habitat Preferences Additional Information

Distribution References

Fish & Fish, 1996, Dickinson, 1963, Dixon & Irvine, 1977, Maggs & Pueschel, 1989, Lüning, 1990, JNCC, 1999, Picton & Costello, 1998, Lewis, 1964, Connor et al., 1997(a), Hardy & Guiry, 2003,

Reproduction/Life History

Reproductive type

Vegetative
Self-fertilization
Permanent hermaphrodite
See additional information

Developmental mechanism

Spores (sexual / asexual)

Reproductive Season

Insufficient information

Reproductive Location

Reproductive frequency

Annual protracted

Regeneration potential

Life span

6-10 years

Age at reproductive maturity

1-2 years

Generation time

Insufficient information

Fecundity

No information found

Egg/propagule size

Fertilization type

Larvae/Juveniles
Larval/Juvenile dispersal potential	Insufficient information	Larval settlement period
Duration of larval stage	Insufficient information

Reproduction Preferences Additional Information

Life span
No information was found concerning the longevity of Ahnfeltia plicata. However, it is a slow maturing perennial (Dickinson, 1963) and the thallus survives several years without considerable losses (Lüning, 1990). It likely to have a life span of 5-10 years, similar to other red seaweeds, such as Furcellaria lumbricalis.

Age at maturity
No definitive information was found concerning age at maturity. However, Maggs & Pueschel (1989) made observations of Ahnfeltia plicata from Nova Scotia. Tetrasporophyte crusts matured and released tetraspores after 15 months. Gametangial plants had produced abundant monosporangia after 14 months but no other reproductive structures were formed during this time.

Reproductive type
Ahnfeltia plicata has a heteromorphic life history (Maggs & Pueschel, 1989). Carpospores formed on the female thallus as a result of sexual reproduction give rise to the tetrasporophyte encrusting form. In turn, the tetraspores formed on the tetrasporophyte phase give rise to the erect, gametophyte plants. However, male gametophytes also give rise to monosporangia, producing monospores which also develop into gametophytes. Maggs & Pueschel (1989) suggest that the recycling of erect male gametophytes may be important in habitats which are unsuitable for the encrusting phase.

Timing of reproduction
Maggs & Pueschel (1989) recorded observations of reproduction by Ahnfeltia plicata in Nova Scotia. Spermatangia were present on male gametophytes between July and January. Carpogonia were present on female gametophytes between July and November, carposporophytes began development between September and November, and were mature between October and July. Monosporangia, which were only found on male plants in the intertidal, were present from November to January.

Reproduction References

Dickinson, 1963, Dixon & Irvine, 1977, Maggs & Pueschel, 1989, Lüning, 1990,