Further information on where to look - Rocky shores contain an enormous variety of habitats and microhabitats. Before exploring it is worth finding out more about exactly where and how to search for molluscs here.
Very exposed rocky shore
Open shores with a vertical or strongly sloping profile, subject to considerable wave action. Characterised by a wide splash zone, many crevices, low algal diversity.
Associated species include:
- Patella vulgata
- Patella ulyssiponensis (S & W)
- Patella depressa (S & W)
- Melarhaphe neritoides
- Littorina saxatilis
- Littorina arcana (W)
- Littorina compressa (SW & W)
- Nucella lapillus
- Mytillus edulis
- Musculus discors
- Lasaea adansoni
Semi-exposed rocky shore
Less open than the above with a shallower slope and a greater diversity of algae including fucoids, Cladophora and Corallina. Still subject to moderately strong wave action. Often with large rocks. Undersides of rocks often colonised by bryozoans and serpulids.
Associated species include:
- Tectura testudinalis (N)
- Tectura virginea
- Helcion pellucidum
- Osilinus lineatus (SW & W)
- Gibbula umbilicalis (S & W)
- Gibbula cineraria
- Tricolia pullus
- Littorina littorea
- Littorina obtusata
- Littorina fabalis
- Lacuna pallidula
- Rissoa parva
- Rissoa interrupta
- Hiatella arctica
- Heteranomia squamula
- Turtonia minuta
Sheltered rocky shores
Often has extensive ledge systems with low wave action. Contains many pools, crevices and overhangs, and a high diversity of algae and other animals.
The fauna includes many of the species from the list for semi-exposed shores but less of the species on the exposed shore list. The additional fauna is almost endless depending on the degree of shelter and overall species richness of the site, however, the following are typical:–
- Calliostoma zizyphinum
- Lacuna vincta
- Lacuna parva
- rissoids
- Trivia arctica
- Trivia monacha
- Lamellaria latens
- Lamellaria perspicua
- Buccinum undatum
- Hinia incrassata
- Chlamys varia
- Venerupis senegalensis