BIOTIC

BIOTIC Species Information for Lacuna vincta

Researched by

Angus Jackson

Data supplied by

MarLIN

Refereed by

Dr John Grahame

Taxonomy

Scientific name

Lacuna vincta

Common name

Banded chink shell

MCS Code

W292

Recent Synonyms

Lacuna carinata Kozloff, 1987.

Phylum

Mollusca

Subphylum

Superclass

Class

Gastropoda

Subclass

Prosobranchia

Order

Mesogastropoda

Suborder

Family

Littorinidae

Genus

Lacuna

Species

vincta

Subspecies

Additional Information

The taxonomy of the Gastropoda has been recently revised (see Ponder & Lindberg 1997, and Taylor 1996). Ponder & Lindberg (1997) suggest that Mesogastropoda should be included in a monophyletic clade, the Caenogastropoda.

Taxonomy References

Howson & Picton, 1997, Campbell, 1994, Hayward & Ryland, 1995b, Ponder & Lindberg 1997, Taylor, 1996, Bieler, 1992,

General Biology

Growth form

Turbinate

Feeding method

Herbivore

Mobility/Movement

Crawler

Environmental position

Epifaunal

Typical food types

Detritus, periphytic microalgae, macroalgae epidermis.

Habit

Free living

Bioturbator

Not relevant

Flexibility

None (< 10 degrees)

Fragility

Robust

Size

Small(1-2cm)

Height

Insufficient information

Growth Rate

Insufficient information

Adult dispersal potential

100-1000m

Dependency

Independent

Sociability

Solitary

Toxic/Poisonous?

General Biology Additional Information

Lacuna is a northern genus and the British Isles are near the southern edge of the range of this species. Lacuna vincta is rare in France but in north-east England densities have been recorded at 300 per square metre. In eastern Canada over 1,500 have been recorded per square metre. Adults die after spawning and very few can be found on the shore after April ( in southern Britain). The population is at a maximum in July (in southern Britain). Immediately after metamorphosis the young snail is about 0.55mm high. The brown bands on the shell develop following settlement. There is a very slight but not conclusive sexual dimorphism with the females being slightly larger. As the snail eats, the radula becomes worn down. Teeth are replaced through new growth. The form of the teeth varies depending on what the snail typically feeds on. This is important for determining feeding effectiveness. Sharp teeth are used for rasping and eating macroalgae whereas broader blunter teeth are used for scraping microalgae from the surface of plants. They do not graze algal film on rocks like the similar winkles.

Biology References

Hayward et al., 1996, Graham, 1988, Hayward & Ryland, 1995b, Martel & Chia, 1991a, Padilla et al., 1996, Fretter & Graham, 1994, Fretter & Manly, 1977, Grahame, 1977,

Distribution and Habitat

Distribution in Britain & Ireland

Found on all British and Irish coasts.

Global distribution

Circumboreal extending south to Brittany.

Biogeographic range

Not researched

Depth range

Low shore to 40

Migratory

Seasonal (reproduction)

Distribution Additional Information

The species is found on a wide variety of coasts round the British Isles. It occasionally settles from the plankton as high as the mid tide level but is more typically found much further down the shore. The larvae settle out on a variety of algal species. The preferred species in the British Isles include Fucus serratus, Laminaria spp. and on red algal turf, particularly Lomentaria articulata. Also sometimes found on Zostera spp. Lacuna vincta has been recorded in salinities as low as 12-13 psu. Larval settlement from the plankton may occur in water velocities of 2.2m/s. There is a possible inshore migration by subtidal individuals in spring for breeding. The species requires considerable shelter from wave action and water flow. It acquires this shelter by selecting suitable habitats Exposure to adversely strong water currents may result in lifting of the foot and production of long sticky mucus threads allowing passive drifting in the water column to disperse to better conditions.

Substratum preferences

Algae

Physiographic preferences

Open coast
Sealoch
Ria / Voe
Estuary

Biological zone

Wave exposure

Moderately Exposed
Sheltered
Very Sheltered
Extremely Sheltered

Tidal stream strength/Water flow

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

Salinity

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

Habitat Preferences Additional Information

Distribution References

Campbell, 1994, Hayward et al., 1996, Hayward & Ryland, 1995b, Fretter & Graham, 1994, Fretter & Manly, 1977, Martel & Diefenbach, 1993,

Reproduction/Life History

Reproductive type

Gonochoristic

Developmental mechanism

Planktotrophic

Reproductive Season

All year

Reproductive Location

Insufficient information

Reproductive frequency

Annual protracted

Regeneration potential

Life span

<1 year

Age at reproductive maturity

<1 year

Generation time

<1 year

Fecundity

1,000-1,500 eggs per spawn

Egg/propagule size

Ca 100 µm

Fertilization type

Larvae/Juveniles
Larval/Juvenile dispersal potential	>10km	Larval settlement period	Peak May/June or September: See additional info.
Duration of larval stage	1-6 months

Reproduction Preferences Additional Information

In the field the species survives for a year or less. Survival rates are very low. Only 2-5 percent of the population will reach maturity. An estimate of the number of eggs per female per season is 53,500. Each spawn mass contains 1,000 - 1,500 eggs. The egg mass has a definite ring doughnut shape and the colour of the mass varies with diet. Individual egg size is around 100 microns. Development inside the egg takes 2.5 to 3.5 weeks. Spawning occurs throughout the year but there is a distinct peak. In southern Britain this peak is in winter resulting in main larval settlement in late May / early June. Further north settlement peaks in September. Cold temperatures may delay oviposition. Settlement is probably induced by organic properties of substrata beneficial to the adult rather than the presence of or exudate from other individuals of the species.

Reproduction References

Martel & Chia, 1991a, Grahame, 1994, Fretter & Graham, 1994, Fretter & Manly, 1977, Smith, 1973,