APHOTOMARINE

An educational resource dedicated mainly to the photography
and diversity of marine life that is found in the coastal waters
and rockpools of south-west England. Images by David Fenwick.

Beachcombing - List of trans-atlantic rafting species
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Trans-atlantic rafting molluscs

The list here has been made because of the volume of new species washing up on the beaches around the UK , winter 2015/16, that have originated from the east coast of the United States of America, Gulf of Mexico, Caribbean or beyond. Only rafting species have been listed, so animals that depend on either wood, seeds or flotsam e.g. plastic refuse and fishing gear, for getting across the Atlantic. Most cosmopolitan species have been left off the list. These are species that occur on both sides of the Atlantic. Pelagic species such as Gooseneck barnacles (Lepas) have been added, as these are frequently found on the shore and may come from a south-westerly direction, they also may be associated with trans-atlantic rafting species.

The list of molluscs and other species above has been produced to promote the current stranding of non-native species on our shores, its purpose, to alert beachcombers, scientists and the wider general public, of what is happening.

Its main intent however is to alert those who regularly visit beaches and who may find such species, as it is important that we make the best inventory possible. Because the information here is mainly for the general public I must remind those who write scientific papers that permission is needed to reproduce or part reproduce any list that appears here.

Bivales (Mollusca)

Anadara transversa (Say, 1822) - Transverse ark

Arca zebra (Swainson, 1833) - Turkey Wing

Martesia fragilis Verrill & Bush, 1898
- A Wood piddock

Martesia striata (Linnaeus, 1758)
- Striate wood piddock or Wood piddock

Chama congregata Conrad, 1833 - Corrugated jewel box clam or Corrugated jewelbox

Chama macerophylla Gmelin, 1791
- Leafy jewel box clam or Leafy jewelbox

Chama sarda Reeve, 1847 - Cherry jewel box clam

Spondylus tenuis Schreibers, 1793
syn. Spondylus ictericus - Digitate thorny oyster

Brachidontes exustus (Linnaeus, 1758)
- Scorched mussel

Musculus sp. - A Mussel (finder Dr. P. Gainey 1986)

Mytilus trossulus Gould, 1850
- Foolish or Pacific blue mussel (native)

Dendostrea frons (Linnaeus, 1758)
- Frond or 'Coon oyster

Ostrea equestris Say, 1834 - Crested or Horse oyster

Anomia simplex d'Orbigny, 1853
- Common jingle shell

Heteranomia squamula (Linnaeus, 1758)
- Prickly saddle oyster (cosmopolitan)

Pododesmus rudis (Broderip, 1834)
- False jingle shell

Aequipecten opercularis (Linnaeus, 1758)
- Queen scallop as Aequipecten heliacus (Dall, 1925)

Argopecten gibbus (Linnaeus, 1758)
- Atlantic calico scallop

Euvola ziczac (Linnaeus, 1758) - Zigzag scallop

Isognomon bicolor (C. B. Adams, 1845)
- Bicolor purse-oyster

Isognomon radiatus (Anton, 1838)
- Radial purse-oyster

Pinctada imbricata imbricata Röding, 1798
- Atlantic Pearl Oyster

Pteria colymbus (Röding, 1798) - A Wing oyster

Pinna carnea Gmelin, 1791 - Amber pen shell

Marine snails (Mollusca)

Cerithium litteratum (Born, 1778)
- Stocky cerith or Lettered horn shell

Stramonita floridana (Conrad, 1837)
- Florida rock snail

Sea slugs (Mollusca)

Fiona pinnata (Eschscholtz, 1831) - Noble aeolis

Other confirmed trans-atlantic rafting species

Cnidaria / Scyphozoa (True jellyfish)

Linuche unguiculata (Schwartz, 1788)
- Thimble jellyfish (non-native species)

Cnidaria / Hydrozoa (Sea firs / hydroids)

Millepora species - A Fire coral

Cnidaria / Scleractinia (Stony, Hard and Cup corals)

Astrangia species - A Stone coral

Bryozoa (Sea mats)

Akatopora tincta (Winston and Vieira 2013)
- A cheilostome bryozoan (non-native NW Atlantic species)

Membranipora tenuis Desor, 1848 ?
- A cheilostome bryozoan (cosmopolitan)

Foraminifera (Forams or Hole bearers)

Homotrema rubra (Lamarck, 1816)
- A non-native hole bearer or foram from USA

Annelida (Marine worms)

Spirobranchus americanus (Day, 1973)
- A Keeled tubeworm

Platyhelminthes (Marine flatworms)

Astrotorhynchus bifidus (McIntosh, 1874)

Crustacea (Barnacles)

Balanus trigonus Darwin, 1854 - A Barnacle

Dosima fascicularis Ellis & Solander, 1786
- Buoy barnacle

Lepas (Anatifa) anatifera Linnaeus, 1758
- Common goose, Smooth goose-neck or Ship barnacle

Lepas (Anatifa) anserifera Linnaeus, 1767
- A Goose, Goose-neck or Stalked barnacle

Lepas (Anatifa) hillii Leach, 1818
- A Goose, Goose-neck or Stalked barnacle

Lepas (Anatifa) pectinata Spengler, 1793
- A Goose-neck or Duck barnacle

Conchoderma virgatum Spengler, 1789

Crustaceans (Amphipods)

Caprella andreae Mayer, 1890 - A Skeleton shrimps

Crustacea (Isopods)

Idotea metallica Bosc, 1802 - An Isopod

Crustacea (Crabs)

Planes minutus (Linnaeus, 1758)
- Columbus or Gulf-weed crab

Algae on flotsam

There are likely to be hundreds of species of algae, some microscopic, that cross the Atlantic on items of flotsam, which is why I'm not going to attempt to mention them all here, but just mention two or three interesting ones.

Anadyomene stellata (Wulfen) C.Agardh, 1823
- Common sea kale (non-native species)

Petalonia zosterifolia (Reinke) Kuntze, 1898
- A Brown algae

Likely trans-atlantic rafting molluscs

Arca imbricata Bruguière, 1789 - Mossy ark

Lunarca ovalis (Bruguière, 1789)
syn. Anadara ovalis - Blood ark clam

Isognomon alatus (Gmelin, 1791)
- Flat tree oyster

Chama florida Lamarck, 1819
- Pretty jewel box clam or Pretty jewelbox

Spondylus americanus Hermann, 1781
- Atlantic thorny oyster

Choristodon robustus (Sowerby I, 1834)
- An Atlantic petricolid

Mulinia lateralis (Say, 1822) - Dwarf surf or Coot clam

Brachidontes modiolus (Linnaeus, 1767) - Yellow mussel

Geukensia demissa (Dillwyn, 1817)
- Atlantic ribbed mussel

Mytilopsis leucophaeata (Conrad, 1831)
- Conrad's or Dark false mussel

Perna viridis (Linnaeus, 1758) - Asian green mussel

Plicatula gibbosa Lamarck, 1801 - Atlantic kitten's paw

Crassostrea gigas (Thunberg, 1793)
- Portuguese or Rock oyster

Crassostrea rhizophorae (Guilding, 1828)
- Mangrove or Mangrove cupped oyster

Crassostrea virginica (Gmelin, 1791)
- Eastern oyster

Atrina rigida (Lightfoot, 1786) - Stiff pen shell

Atrina serrata (G. B. Sowerby I, 1825)
- Saw-tooth pen shell

Atrina seminuda (Lamarck, 1819) - Half-naked pen shell

Pinna rudis Linnaeus, 1758
- Rough pen shell or Spiny fan-mussel

Costoanachis avara (Say, 1822)
- Greedy dove shell

Costoanachis sparsa (Reeve, 1859)
- Sparse dove shell

Cotonopsis lafresnayi (P. Fischer & Bernardi, 1856)
- Well-ribbed dove shell

Nitidella nitida (Lamarck, 1822) - Glossy dove shell

Lithopoma americanum (Gmelin, 1791)
- American Starsnail

There are many other molluscs and other species that could turn up in the UK, either on plastic flotsam, floats, buoys, orange or other colours of Scotty bait jars, fishing gear or on logs etc., the list above is just a general guide.

Other NW Atlantic / Gulf of Mexico / Caribbean
species of molluscs

Codakia orbicularis (Linnaeus, 1758) - Tiger lucine

Donax variabilis Say, 1822 - Coquina clam

Crepidula convexa Say, 1822
- Convex slippersnail / slipper limpet

Crepidula fornicata (Linnaeus, 1758)
- American slippersnail / slipper limpet

Crepidula plana Say, 1822
- Eastern white slippersnail / slipper limpet

Eupleura caudata (Say, 1822) - Thick-lipped Oyster Drill

Identification and recording --

I am quite prepared to receive records or images of any unusual find that appears around the UK and help identify biological material. E-mail

Further information -

Southwest Florida Shell Guide with
emphasis on Sanibel & Captiva

The Shells of Sunset Beach, North Carolina

Buying shells from Florida and the Gulf of Mexico

Florida Seashells And Fossils LLC

For more information on rafting and pelagic marine
species the following book is highly recommended.

The Essential Guide to Beachcombing and the Strandline

Marine Bivalve Images Gaping file or Flame shells Order Limoida