MarLIN

information on the biology of species and the ecology of habitats found around the coasts and seas of the British Isles

Lobe shell (Philine aperta)

Distribution data supplied by the Ocean Biogeographic Information System (OBIS). To interrogate UK data visit the NBN Atlas.

Summary

Description

Philine aperta can grow up to 7 cm long, 3.5 cm wide and has a small internal shell that can be felt at the hind end of the animal. The soft body is four-lobed and whitish to pale yellow in colour with white dots. This species characteristically secretes sulphuric acid as a defence against predators.

Recorded distribution in Britain and Ireland

At a few recorded locations all around the British Isles.

Global distribution

Norway to the Mediterranean Sea, South Africa, Sri Lanka and the Philippines.

Habitat

A sublittoral sea slug spending most of its life beneath the surface of the sand/muddy sand in which it seeks its prey.

Depth range

0-500m

Identifying features

  • Quadripartite; right and left parapodial lobes, cephalic shield (head), and posterior mantle lobe over the visceral mass.
  • Whitish to pale yellow in colour with white dots; up to 7 cm in length.
  • Internal shell with very wide aperture; delicate, whitish in colour.

Additional information

No text entered

Listed by

- none -

Further information sources

Search on:

Biology review

Taxonomy

PhylumMollusca
ClassGastropoda
OrderCephalaspidea
FamilyPhilinidae
GenusPhiline
Authority(Linnaeus, 1767)
Recent Synonyms

Biology

Typical abundanceModerate density
Male size range7 cm
Male size at maturity
Female size rangeSmall-medium(3-10cm)
Female size at maturity
Growth formGlobose
Growth rateData deficient
Body flexibilityLow (10-45 degrees)
MobilityBurrower
Characteristic feeding methodPredator
Diet/food sourceCarnivore
Typically feeds onPectinaria koreni, Echinocyamus pusillus, foraminiferans, and small infaunal lamellibranchs and gastropods.
SociabilitySolitary
Environmental positionInfaunal
DependencyIndependent.
SupportsNo information
Is the species harmful?Yes

Sulphuric acid secretion from the skin give it some protection from predators, which include fish.

Biology information

  • Philine aperta lives just beneath the surface of fine sediment. The species 'ploughs' through the sediment as it moves and should not really be considered as burrowing species.
  • Although the species has an internal shell, this is small relative to the total body size and there is therefore, some flexibility.
  • A scavenging habit was observed under laboratory conditions on freshly killed bivalves.

Habitat preferences

Physiographic preferencesData deficient
Biological zone preferencesLower eulittoral, Sublittoral fringe, Upper infralittoral
Substratum / habitat preferencesFine clean sand, Muddy sand, Sandy mud
Tidal strength preferences
Wave exposure preferences
Salinity preferencesData deficient
Depth range0-500m
Other preferencesNo text entered
Migration PatternData deficient

Habitat Information

No text entered

Life history

Adult characteristics

Reproductive typePermanent (synchronous) hermaphrodite
Reproductive frequency Annual episodic
Fecundity (number of eggs)10,000-100,000
Generation timeInsufficient information
Age at maturityInsufficient information
SeasonApril - August
Life span2-5 years

Larval characteristics

Larval/propagule type-
Larval/juvenile development Planktotrophic
Duration of larval stage1-6 months
Larval dispersal potential Greater than 10 km
Larval settlement periodInsufficient information

Life history information

Longevity is believed to be 3-4 years. In Britain spawning has been recorded from spring to summer when flask-shaped egg masses are laid. Egg masses may each contain up to 50,000 white ova. Veliger larvae hatch after a few days.

Sensitivity reviewHow is sensitivity assessed?

Physical pressures

 IntoleranceRecoverabilitySensitivityEvidence/Confidence
High High Moderate Moderate
Philine aperta is an infaunal species and so loss of substratum would result in loss of the population. Intolerance is therefore, assessed as High. Recovery would be high due to the fast growth, fast reproductive rates of the species and recolonization from other areas as the species is common where it occurs.
Tolerant Not relevant Not sensitive Moderate
Philine aperta lives just beneath the surface of the sediment and is capable of moving through it. Therefore, smothering by a layer of 5 cm would have little or no effect on the species and a rank of not sensitive is recorded. Impermeable materials, such as concrete, oil or tar, are likely to have a greater effect.
Tolerant Not relevant Not sensitive Moderate
Philine aperta is a carnivore and lives buried under the sediment surface, therefore an increase in suspended sediments is unlikely to have an effect on the population or the burrowing organisms that they feed on.
No information
Not relevant Not relevant Not relevant Moderate
The subtidal position and soft-bodied nature of this species suggests that it is unlikely to tolerate desiccation. However, the species is sufficiently mobile and capable of burrowing therefore, it is likely to be able to move to an area which is more favourable. Recovery would be high, provided conditions were suitable, due to the fast growth, fast reproductive rates of the species and recolonization from other areas as the species is common where it occurs.
Not relevant Not relevant Not relevant Moderate
The subtidal position and soft-bodied nature of this species suggests that it is unlikely to tolerate emersion as it would suffer desiccation. However, the species is sufficiently mobile and capable of burrowing therefore, it is likely to be able to move to an area which is more favourable. Recovery would be high due, provided conditions were suitable, to the fast growth, fast reproductive rates of the species and recolonization from other areas as the species is common where it occurs.
No information
High High Moderate Moderate
The species is found predominantly on finer sediments which are associated with sheltered locations. Increased water flow rate is likely to change the nature of sediment and hence the character of the habitat as fine particles are washed away. Increased water flow rate could also sweep adults away and so intolerance is recorded as high.
No information
Low High Low Low
Spawning, hatching and time to metamorphosis are all temperature dependent. Spawning occurs during the warmest months of the year (April to August) (Lancaster, 1983). Laboratory results showed hatching occurred after 3.5 days at 23°C and 8 days at 13°C (Thompson, 1976) and time to metamorphosis occurred after 35-40 days at 12-13°C and 30 days at 15°C (Hansen & Ockelmann, 1991). A change in temperature at the benchmark level would be unlikely to have lethal effects however, and an intolerance of low is recorded. Colder temperatures would delay development and recruitment to a population.
No information
Tolerant Not relevant Not sensitive Moderate
Neither the species or the burrowing organisms on which it lives are dependant on light availability, so it would not be affected by a change in turbidity.
No information
High High Moderate Moderate
The species is found predominantly on finer sediments which are associated with wave sheltered locations. Increased wave exposure is likely to erode fine sediments and displace adult Philine aperta. Intolerance to wave exposure is therefore assessed as High.
No information
Tolerant Not relevant Not sensitive Low
The species probably has very limited capacity for noise perception.
Tolerant Not relevant Not sensitive Low
The species probably has very limited capacity for visual perception.
Intermediate High Low Moderate
The species is soft bodied and has a delicate internal shell and therefore likely to be damaged on impact by a passing scallop dredge. Therefore, a proportion of the population is likely to be lost and an intolerance of intermediate has been recorded. Recovery would be high due to the fast growth, fast reproductive rates of the species and recolonization from other areas, as the species is common.
Tolerant Not relevant Not sensitive Moderate
Philine aperta is sufficiently mobile to be able to deal with displacement provided a suitable substratum is found.

Chemical pressures

 IntoleranceRecoverabilitySensitivityEvidence/Confidence
No information No information No information Not relevant
Insufficient
information
Heavy metal contamination
No information No information No information Not relevant
Insufficient
information
Hydrocarbon contamination
No information No information No information Not relevant
Insufficient
information
Radionuclide contamination
No information No information No information Not relevant
Insufficient
information
Changes in nutrient levels
No information No information No information Not relevant
Insufficient
information
No information No information No information Not relevant
Insufficient
information
No information
No information No information No information Not relevant
Insufficient
information

Biological pressures

 IntoleranceRecoverabilitySensitivityEvidence/Confidence
No information No information No information Not relevant
Insufficient
information
No information No information No information Not relevant
Insufficient
information
Not relevant Not relevant Not relevant Low
It is extremely unlikely that this species would be subject to extraction as it has no commercial and limited research value. A small number may removed or damaged by benthic trawls and dredges.
Tolerant Not relevant Not sensitive Low
Philine aperta has no known obligate relationships.

Additional information

Importance review

Policy/legislation

- no data -

Status

Non-native

Importance information

-none-

Bibliography

  1. Fish, J.D. & Fish, S., 1996. A student's guide to the seashore. Cambridge: Cambridge University Press.

  2. Hansen, B. & Ockelmann, K.W., 1991. Feeding behaviour in larvae of the opisthobranch Philine aperta. I. Growth and functional response at the different developmental stages. Marine Biology, 111, 255-261.

  3. Hansen, B., 1991. Feeding behaviour in larvae of the opisthobranch Philine aperta. II. Food size spectra and particle selectivity in relation to larval behaviour and morphology of the velar structures. Marine Biology, 111, 263-270.

  4. Hayward, P., Nelson-Smith, T. & Shields, C. 1996. Collins pocket guide. Sea shore of Britain and northern Europe. London: HarperCollins.

  5. Hayward, P.J. & Ryland, J.S. (ed.) 1995b. Handbook of the marine fauna of North-West Europe. Oxford: Oxford University Press.

  6. 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.]

  7. Lancaster, S.M., 1983. The biology and reproductive ecology of Philine aperta (Opisthobranchia: Bullomorpha) in Oxwich Bay. Journal of Molluscan Studies, Suppl. 12A, 82-88.

  8. Thompson, T. E. & Brown, G. H., 1976. British Opisthobranch Molluscs. London: Academic Press. [Synopses of the British Fauna, no. 8.]

  9. Thompson, T.E., 1976. Biology of Opisthobranch Molluscs, vol. 1. London: The Ray Society.

Citation

This review can be cited as:

Wilson, E. 2000. Philine aperta Lobe shell. In Tyler-Walters H. and Hiscock K. (eds) Marine Life Information Network: Biology and Sensitivity Key Information Reviews, [on-line]. Plymouth: Marine Biological Association of the United Kingdom. Available from: http://www.marlin.ac.uk/species/detail/1412

Last Updated: 25/10/2000