BIOTIC

BIOTIC Species Information for Neocrania anomala

Researched by

Lizzie Tyler

Data supplied by

University of Sheffield

Refereed by

This information is not refereed.

Taxonomy

Scientific name

Neocrania anomala

Common name

A brachiopod

MCS Code

Recent Synonyms

Crania anomala

Phylum

Brachiopoda

Subphylum

Superclass

Class

Inarticulata

Subclass

Order

Acrotretida

Suborder

Family

Craniidae

Genus

Novocrania

Species

anomala

Subspecies

Additional Information

Unusually for the inarticulate brachiopods, the shell contains calcium carbonate. In brachiopods the valves of the shell are dorso-ventral, whereas in bivlave molluscs the valves are lateral.

Taxonomy References

Brunton & Curry, 1979, Howson & Picton, 1997, James et al., 1992, Rowell, 1960,

General Biology

Growth form

Bivalved

Feeding method

Passive suspension feeder
Active suspension feeder

Mobility/Movement

Permanent attachment

Environmental position

Epifaunal

Typical food types

Seston

Habit

Attached

Bioturbator

Not relevant

Flexibility

None (< 10 degrees)

Fragility

Intermediate

Size

Small(1-2cm)

Height

Not researched

Growth Rate

Insufficient information

Adult dispersal potential

Not researched

Dependency

Independent

Sociability

Solitary

Toxic/Poisonous?

General Biology Additional Information

The lophophore forms the main feeding organ. Mucus is not used in particle capture, only for transport. Neocrania anomala exhibits some degree of particle selectivity. There is a complex mechanism for particle rejection. There is little information on growth rate except that it is believed to be represented by an exponentially declining curve but dependent on depth, food, population density etc. Growth after the first year is slow. Four or five year classes can be identified. Neocrania anomala is capable of recovery from considerable damage to the shell and soft tissue. The adults can be maintained quite well in aquaria and are generally hardy organisms.

Biology References

Brunton & Curry, 1979, James et al., 1992, Atkins & Rudwick, 1962, Harper, 1991,

Distribution and Habitat

Distribution in Britain & Ireland

From the Firth of Clyde up the west coast of Scotland including the Hebrides, Shetland, the south coast of England and the Isle of Man. In Ireland along the south coast, the north-west and the north-east.

Global distribution

From the Canary Isles, the Britain Isles, the Faeroe Isles, Norway, Iceland and Spitzbergen.

Biogeographic range

Not researched

Depth range

Migratory

Non-migratory / Resident

Distribution Additional Information

Absent from the Irish Sea and from the east coast of Britain.

Substratum preferences

Other species (see additional information)
Bedrock
Large to very large boulders
Small boulders

Physiographic preferences

Open coast
Offshore seabed
Sealoch

Biological zone

Lower Infralittoral
Upper Circalittoral
Lower Circalittoral

Wave exposure

Moderately Exposed
Sheltered
Very Sheltered
Extremely Sheltered
Ultra Sheltered

Tidal stream strength/Water flow

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

Salinity

Full (30-40 psu)

Habitat Preferences Additional Information

Can often be found living on Modiolus sp. or empty scallop shells.

Distribution References

Brunton & Curry, 1979, James et al., 1992, Atkins & Rudwick, 1962, Harper, 1991, Rowell, 1960,

Reproduction/Life History

Reproductive type

Gonochoristic

Developmental mechanism

Lecithotrophic

Reproductive Season

April to November

Reproductive Location

Water column

Reproductive frequency

Annual protracted

Regeneration potential

Life span

6-10 years

Age at reproductive maturity

Generation time

Insufficient information

Fecundity

Egg/propagule size

122.5 µm diameter

Fertilization type

External

Larvae/Juveniles
Larval/Juvenile dispersal potential	100-1000m	Larval settlement period	Insufficient information
Duration of larval stage	2-10 days

Reproduction Preferences Additional Information

Longevity is suspected to be between 8-10 years. There is no obvious sexual dimorphism although the colour of the gonads may be distinguishing. Testes are light coloured white, pink, cream or blue and ovaries are orange-brown. Egg diameter is 120-125 microns. The species is free-spawning and fertilization is external in the surrounding water column. The eggs are more dense than seawater hatching into a free-swimming larval stage. The larvae are fully developed within three days and settle out in no more than a few days. Most of the literature suggests that dispersal ability is not great. Although the species may inhabit areas with water flow rates of up to 3 knots, the often restricted and sheltered habitat such as sea lochs may reduce dispersal ability. The breeding season in western Scotland has been inferred from the presence of recently settled juveniles. The larva may be able to delay settlement if the initial substratum is unsuitable or the water is too deep.

Reproduction References

James et al., 1992, Rowell, 1960, Long & Stricker, 1991,