APHOTOMARINE

An educational resource dedicated mainly to the photography
and diversity of marine life that can be found in coastal waters
and intertidal areas of Great Britain and Ireland by David Fenwick.

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Portuguese or Rock oyster
Magallana gigas
- valves of single specimen 1

Portuguese or Rock oyster
Magallana gigas
- dorsal view shell 1

Portuguese or Rock oyster
Magallana gigas
- ventral view shell 1

Portuguese or Rock oyster
Magallana gigas
- with 1.0mm division rule 1

Portuguese or Rock oyster
Magallana gigas
- shell prior to cleaning 1

Portuguese or Rock oyster
Magallana gigas
- habitat / location 1

The dead shell above was found with live specimens on the lowershore under the Tamar road bridge at Saltash, Cornwall, 19.01.22.

Portuguese or Rock oyster
Magallana gigas
- group collected specimens 1

Portuguese or Rock oyster
Magallana gigas
- group in-situ 1

Portuguese or Rock oyster
Magallana gigas
- pair in-situ 1

Portuguese or Rock oyster
Magallana gigas
- pair in-situ 2

Portuguese or Rock oyster
Magallana gigas
- specimen on bare rock 1

Portuguese or Rock oyster
Magallana gigas
- reef / habitat being invaded 1

Portuguese or Rock oyster
Magallana gigas
- dorsal surface / collection 1

Portuguese or Rock oyster
Magallana gigas
- interior twelve specimens 1

Portuguese or Rock oyster
Magallana gigas
- interior three specimens 1

Portuguese or Rock oyster
Magallana gigas
- with 1.0mm division rule 2

Portuguese or Rock oyster
Magallana gigas
- shell with flesh / meat 1

The juvenile specimens above were found colonizing rocks at Chyandour, Penzance, Cornwall. 21.06.16. The sudden arrival of thousands, perhaps tens of thousands of non-native invasive oysters in an area of reef that was situated beside a Marine Conservation Zone was a cause for concern. The specimens here were also confusing as some looked very much like Ostrea chilensis, the Chilean oyster, and not Crassostrea gigas as one would expect. CEFAS, contacted via the Natural History Museum in London kindly agreed to DNA sequence the specimens to conclusively determine the species involved. The species was found to be the most common invasive oyster Crassostrea gigas.

Portuguese or Rock oyster
Magallana gigas
- in Penzance Harbour 1

Portuguese or Rock oyster
Magallana gigas
- in Penzance Harbour 2

Portuguese or Rock oyster
Magallana gigas
- in Penzance Harbour 3

Portuguese or Rock oyster
Magallana gigas
- in Penzance Harbour 4

Very numerous, specimens found on harbour walls, on road bridge pillars, under rocks and free on mixed sediment in Penzance Harbour, Penzance, Cornwall, 05.09.17.

Portuguese or Rock oyster
Magallana gigas
- on middleshore near Newlyn 1

Portuguese or Rock oyster
Magallana gigas
- on middleshore near Newlyn 2

Specimens above found on rocks on the middleshore south of Sandy Cove, Newlyn, Cornwall, 27.07.17.

Portuguese or Rock oyster
Magallana gigas
- live animal / habitat 1

Portuguese or Rock oyster
Magallana gigas
- live animal / habitat 2

Portuguese or Rock oyster
Magallana gigas
- live animal / habitat 3

Portuguese or Rock oyster
Magallana gigas
- top valve 1

Portuguese or Rock oyster
Magallana gigas
- top valve 2

Portuguese or Rock oyster
Magallana gigas
- top valve 3

Portuguese or Rock oyster
Magallana gigas
- left and right valves 1

Portuguese or Rock oyster
Magallana gigas
- left and right valves / inside 1

Images taken at Jennycliif Beach and Batten Bay, near Plymouth, Devon; and near the dock wall at Par Beach, near St. Austell, Cornwall.

Portuguese or Rock oyster
Magallana gigas
- 10mm dia. juvenile 1

Specimen above found on a rock on the middleshore at Chimney Rocks, Penzance, Cornwall, 18.04.18.

Scientific and European Names:
Magallana gigas, Crassostrea gigas, Pacific cupped oyster, Portuguese oyster, Japanese oyster, Rock oyster, Miyagi oyster, Wystrysen portiwgal, Japanse oester, Portugese oester, Huitre creuse, Huitre portugaise, Felsenauster, Pazifische auster, Portugiesische auster, Japanskt jatteostron.

The main objective of this website is in furthering environmental awareness and education through the medium of photography. To increase awareness and access to the wildlife of the region and help

people find and identify it. Sometimes the difference between species is obvious but many species can only be determined by observing microscopic characteristics that are specific to any one species.